Increase version number to 0.3.8

Add instructions to install on Arch Linux through AUR.

.checkpatch.conf

@@ -16,6 +16,12 @@
 # Show file line, not input line
 --showfile
 
+# Don't expect SPDX tag in the first line of a file
+--ignore SPDX_LICENSE_TAG
+
+# Don't expect Signed-off-by lines in commit messages
+--no-signoff
+
 # List of ignored rules
 # ---------------------
 
@@ -53,6 +59,9 @@
 # Prefer stdint.h types over kernel types
 --ignore PREFER_KERNEL_TYPES
 
+# Don't ask to replace sscanf by kstrto
+--ignore SSCANF_TO_KSTRTO
+
 # Parentheses can make the code clearer
 --ignore UNNECESSARY_PARENTHESES
 

.gitignore

@@ -5,3 +5,7 @@ rgbgfx
 *.o
 *.exe
 .checkpatch-camelcase.*
+
+test/pokecrystal/*
+test/pokered/*
+test/ucity/*

.travis-checkpatch.sh

@@ -0,0 +1,48 @@
+#!/bin/bash
+
+echo "Checking code style..."
+
+# Return failure as soon as a command fails to execute
+
+set -e
+
+# Download checkpatch.pl and related files
+
+echo "Getting checkpatch.pl..."
+
+mkdir checkpatchdir
+
+wget https://raw.githubusercontent.com/torvalds/linux/master/scripts/checkpatch.pl
+mv checkpatch.pl checkpatchdir/checkpatch.pl
+chmod +x checkpatchdir/checkpatch.pl
+
+touch checkpatchdir/const_structs.checkpatch
+touch checkpatchdir/spelling.txt
+
+# Run checkpatch.pl on the new commits
+
+echo "Running checkpatch.pl..."
+
+fname=$(mktemp)
+rc=0
+
+git remote set-branches --add origin develop
+git fetch
+
+make CHECKPATCH=checkpatchdir/checkpatch.pl checkpatch > $fname
+
+cat $fname
+
+if grep "ERROR" $fname; then
+    # At least one error found
+    echo "Code style errors have been found!"
+    rc=1
+else
+    echo "No code style errors found, your patches are ready!"
+fi
+
+# Cleanup
+
+rm -rf checkpatchdir
+
+exit $rc

.travis-deps.sh

@@ -2,7 +2,7 @@
 
 if [ $TRAVIS_OS_NAME = "osx" ]; then
     brew update
-    brew install libpng pkg-config
+    brew install libpng pkg-config md5sha1sum
 else # linux
     sudo apt-get -qq update
     sudo apt-get install -y -q bison flex libpng-dev pkg-config

.travis.yml

@@ -6,9 +6,14 @@ install:
   - sudo make install
 os:
   - linux
+  - osx
 compiler:
   - clang
   - gcc
 script:
-  - cd test
-  - ./run-tests.sh
+  - cd test && ./run-tests.sh
+matrix:
+  include:
+    - env: _="checkpatch"
+      script:
+        - ./.travis-checkpatch.sh

CONTRIBUTING.rst

@@ -70,11 +70,14 @@ copyright and the reference to the MIT License.
 3. Create a new branch to work on. You could still work on ``develop``, but it's
    easier that way.
 
-4. Sign off your commits: ``git commit -s``
+4. Compile your changes with ``make develop`` instead of just ``make``. This
+   target checks for additional warnings. Your patches shouldn't introduce any
+   new warning (but it may be possible to remove some warning checks if it makes
+   the code much easier).
 
 5. Follow the Linux kernel coding style, which can be found in the file
    ``Documentation/process/coding-style.rst`` in the Linux kernel repository.
-   Note that the coding style isn't writen on stone, if there is a good reason
+   Note that the coding style isn't written in stone, if there is a good reason
    to deviate from it, it should be fine.
 
 6. Download the files ``checkpatch.pl``, ``const_structs.checkpatch`` and
@@ -90,4 +93,4 @@ copyright and the reference to the MIT License.
 8. Create a pull request against the branch ``develop``.
 
 9. Be prepared to get some comments about your code and to modify it. Tip: Use
-   ``git rebase -i origin/develop`` to modify chains of commits.
+    ``git rebase -i origin/develop`` to modify chains of commits.

CONTRIBUTORS.rst

@@ -28,8 +28,12 @@ Other contributors
 
 - Christophe Staïesse <chastai@skynet.be>
 
+- David Brotz <dbrotz007@gmail.com>
+
 - The Musl C library <http://www.musl-libc.org>
 
+- obskyr <powpowd@gmail.com>
+
 - The OpenBSD Project <http://www.openbsd.org>
 
 - Sanqui <gsanky@gmail.com>

Makefile

@@ -26,7 +26,7 @@ PNGLDLIBS	:= `${PKG_CONFIG} --static --libs-only-l libpng`
 
 VERSION_STRING	:= `git describe --tags --dirty --always 2>/dev/null`
 
-WARNFLAGS	:= -Wall -Werror
+WARNFLAGS	:= -Wall
 
 # Overridable CFLAGS
 CFLAGS		:= -g
@@ -48,6 +48,7 @@ all: rgbasm rgblink rgbfix rgbgfx
 rgbasm_obj := \
 	src/asm/asmy.o \
 	src/asm/charmap.o \
+	src/asm/constexpr.o \
 	src/asm/fstack.o \
 	src/asm/globlex.o \
 	src/asm/lexer.o \
@@ -61,7 +62,7 @@ rgbasm_obj := \
 	src/version.o
 
 src/asm/asmy.h: src/asm/asmy.c
-src/asm/locallex.o src/asm/globlex.o src/asm/lexer.o: src/asm/asmy.h
+src/asm/locallex.o src/asm/globlex.o src/asm/lexer.o src/asm/constexpr.o: src/asm/asmy.h
 
 rgblink_obj := \
 	src/link/assign.o \
@@ -160,6 +161,7 @@ install: all
 
 # Target used to check the coding style of the whole codebase. '.y' and '.l'
 # files aren't checked, unfortunately...
+
 checkcodebase:
 	$Qfor file in `git ls-files | grep -E '\.c|\.h' | grep -v '\.html'`; do	\
 		${CHECKPATCH} -f "$$file";					\
@@ -169,6 +171,7 @@ checkcodebase:
 # to the HEAD. Runs checkpatch once for each commit between the current HEAD and
 # the first common commit between the HEAD and origin/develop. '.y' and '.l'
 # files aren't checked, unfortunately...
+
 checkpatch:
 	$Qeval COMMON_COMMIT=$$(git merge-base HEAD origin/develop);	\
 	for commit in `git rev-list $$COMMON_COMMIT..HEAD`; do		\
@@ -180,7 +183,7 @@ checkpatch:
 # Target for the project maintainer to easily create web manuals.
 # It relies on mandoc: http://mdocml.bsd.lv
 
-MANDOC	:= -Thtml -Ios=General -Oman=%N.%S.html -Ostyle=manual.css
+MANDOC	:= -Thtml -Ios=General -Oman=%N.%S.html -Ostyle=mandoc.css
 
 wwwman:
 	$Qmandoc ${MANDOC} src/rgbds.7 > docs/rgbds.7.html
@@ -193,6 +196,25 @@ wwwman:
 	$Qmandoc ${MANDOC} src/link/rgblink.5 > docs/rgblink.5.html
 	$Qmandoc ${MANDOC} src/gfx/rgbgfx.1 > docs/rgbgfx.1.html
 
+# This target is used during development in order to prevent adding new issues
+# to the source code. All warnings are treated as errors in order to block the
+# compilation and make the continous integration infrastructure return failure.
+
+develop:
+	$Qenv make -j WARNFLAGS="-Werror -Wall -Wextra -Wpedantic \
+		-Wno-sign-compare -Wchkp -Wformat=2 -Wformat-overflow=2 \
+		-Wformat-truncation=1 -Wformat-y2k -Wswitch-enum -Wunused \
+		-Wuninitialized -Wunknown-pragmas -Wstrict-overflow=5 \
+		-Wstringop-overflow=4 -Walloc-zero -Wduplicated-cond \
+		-Wfloat-equal -Wshadow -Wcast-qual -Wcast-align -Wlogical-op \
+		-Wnested-externs -Wno-aggressive-loop-optimizations -Winline \
+		-Wundef -Wstrict-prototypes -Wold-style-definition \
+		-fsanitize=shift -fsanitize=integer-divide-by-zero \
+		-fsanitize=unreachable -fsanitize=vla-bound \
+		-fsanitize=signed-integer-overflow -fsanitize=bounds \
+		-fsanitize=object-size -fsanitize=bool -fsanitize=enum \
+		-fsanitize=alignment -fsanitize=null"
+
 # Targets for the project maintainer to easily create Windows exes.
 # This is not for Windows users!
 # If you're building on Windows with Cygwin or Mingw, just follow the Unix
@@ -200,7 +222,7 @@ wwwman:
 
 mingw32:
 	$Qenv PKG_CONFIG_PATH=/usr/i686-w64-mingw32/sys-root/mingw/lib/pkgconfig/ \
-		make CC=i686-w64-mingw32-gcc YACC=bison WARNFLAGS= -j
+		make CC=i686-w64-mingw32-gcc YACC=bison -j
 	$Qmv rgbasm rgbasm.exe
 	$Qmv rgblink rgblink.exe
 	$Qmv rgbfix rgbfix.exe
@@ -208,7 +230,7 @@ mingw32:
 
 mingw64:
 	$Qenv PKG_CONFIG_PATH=/usr/x86_64-w64-mingw32/sys-root/mingw/lib/pkgconfig/ \
-		make CC=x86_64-w64-mingw32-gcc YACC=bison WARNFLAGS= -j
+		make CC=x86_64-w64-mingw32-gcc YACC=bison -j
 	$Qmv rgbasm rgbasm.exe
 	$Qmv rgblink rgblink.exe
 	$Qmv rgbfix rgbfix.exe

README.rst

@@ -55,8 +55,17 @@ To install RGBDS with all of the current changes in development (as seen on the
 .. code:: sh
 
     brew install rgbds --HEAD
+    
+1.3 Arch Linux
+~~~~~~~~~~~~~~
 
-1.3 Other UNIX-like systems
+To install RGBDS through the AUR run
+
+.. code:: sh
+
+    yaourt -S rgbds
+
+1.4 Other UNIX-like systems
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 No official binaries of RGBDS are distributed for these systems, you must follow

docs/gbz80.7.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>GBZ80(7)</title>
 </head>
 <body>
@@ -34,8 +34,12 @@ Note: All arithmetic/logic operations that use register
   is assumed it's register <b class="Sy" title="Sy">A</b>. The following two
   lines have the same effect:
 <div class="Pp"></div>
-<div class="D1"><code class="Li">OR A,B</code></div>
-<div class="D1"><code class="Li">OR B</code></div>
+<div class="Bd" style="margin-left: 5.00ex;">
+<pre class="Li">
+OR A,B 
+OR B
+</pre>
+</div>
 <h1 class="Sh" title="Sh" id="LEGEND"><a class="selflink" href="#LEGEND">LEGEND</a></h1>
 List of abbreviations used in this document.
 <dl class="Bl-tag">
@@ -1144,7 +1148,17 @@ Cycles: 3
 <div class="Pp"></div>
 Bytes: 1
 <div class="Pp"></div>
-Flags: None affected.
+Flags:
+<ul class="Bl-bullet Bl-compact">
+  <li class="It-bullet"><b class="Sy" title="Sy">Z</b>: Set from bit 7 of the
+      popped low byte.</li>
+  <li class="It-bullet"><b class="Sy" title="Sy">N</b>: Set from bit 6 of the
+      popped low byte.</li>
+  <li class="It-bullet"><b class="Sy" title="Sy">H</b>: Set from bit 5 of the
+      popped low byte.</li>
+  <li class="It-bullet"><b class="Sy" title="Sy">C</b>: Set from bit 4 of the
+      popped low byte.</li>
+</ul>
 <h2 class="Ss" title="Ss" id="POP_r16"><a class="selflink" href="#POP_r16">POP
   r16</a></h2>
 Pop register <var class="Ar" title="Ar">r16</var> from the stack.
@@ -1156,7 +1170,11 @@ Bytes: 1
 Flags: None affected.
 <h2 class="Ss" title="Ss" id="PUSH_AF"><a class="selflink" href="#PUSH_AF">PUSH
   AF</a></h2>
-Push register <b class="Sy" title="Sy">AF</b> into the stack.
+Push register <b class="Sy" title="Sy">AF</b> into the stack. The low byte's bit
+  7 corresponds to the <b class="Sy" title="Sy">Z</b> flag, its bit 6 to the
+  <b class="Sy" title="Sy">N</b> flag, bit 5 to the
+  <b class="Sy" title="Sy">H</b> flag, and bit 4 to the
+  <b class="Sy" title="Sy">C</b> flag. Bits 3 to 0 are reset.
 <div class="Pp"></div>
 Cycles: 4
 <div class="Pp"></div>
@@ -1689,7 +1707,7 @@ Flags: See <a class="Sx" title="Sx" href="#XOR_A,r8">XOR A,r8</a>
   <a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.</div>
 <table class="foot">
   <tr>
-    <td class="foot-date">January 26, 2018</td>
+    <td class="foot-date">February 23, 2018</td>
     <td class="foot-os">RGBDS Manual</td>
   </tr>
 </table>

docs/index.html

@@ -1,32 +1,36 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
+<!DOCTYPE html>
 <html>
 <head>
-	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
-	<title>General Information</title>
-	<link rel="stylesheet" type="text/css" href="./style.css">
+  <meta charset="utf-8"/>
+  <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
+  <title>General Information</title>
+  <link rel="stylesheet" type="text/css" href="mandoc.css">
 </head>
 <body>
 <h1>RGBDS — Rednex Game Boy Development System</h1>
 <h2>Table of Contents</h2>
+<ol>
+  <li>General information
+    <ul>
+      <li><a href="rgbds.7.html">RGBDS general information</a></li>
+      <li><a href="rgbds.5.html">RGBDS object file format</a></li>
+    </ul>
+  <li>Language description
+    <ul>
+      <li><a href="rgbasm.5.html">RGBASM language description</a></li>
+      <li><a href="rgblink.5.html">RGBLINK linkerscript language description</a></li>
+      <li><a href="gbz80.7.html">GBZ80 CPU instruction set description</a></li>
+    </ul>
+  <li>Command line usage
+    <ul>
+      <li><a href="rgbasm.1.html">RGBASM command-line usage</a></li>
+      <li><a href="rgblink.1.html">RGBLINK command-line usage</a></li>
+      <li><a href="rgbfix.1.html">RGBFIX command-line usage</a></li>
+      <li><a href="rgbgfx.1.html">RGBGFX command-line usage</a></li>
+    </ul>
+</ol>
+<h2 id="GitHub Repository">GitHub Repository:</h2>
 <ul>
-	<li><a href="rgbds.7.html">RGBDS general information</a>
-</ul>
-<ul>
-	<li><a href="rgbasm.5.html">RGBASM language description</a>
-	<li><a href="rgblink.5.html">RGBLINK linkerscript language description</a>
-	<li><a href="gbz80.7.html">GBZ80 CPU instruction set description</a>
-</ul>
-<ul>
-	<li><a href="rgbasm.1.html">RGBASM command-line usage</a>
-	<li><a href="rgblink.1.html">RGBLINK command-line usage</a>
-	<li><a href="rgbfix.1.html">RGBFIX command-line usage</a>
-	<li><a href="rgbgfx.1.html">RGBGFX command-line usage</a>
-</ul>
-<ul>
-	<li><a href="rgbds.5.html">RGBDS object file format</a>
-</ul>
-<h3 id="GitHub Repository">GitHub Repository:</h3>
-<ul>
-	<li><a href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>
+  <li><a href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a></li>
 </ul>
 </body>

docs/mandoc.css

@@ -0,0 +1,203 @@
+/* $Id: mandoc.css,v 1.22 2017/07/16 18:45:00 schwarze Exp $ */
+/*
+ * Standard style sheet for mandoc(1) -Thtml and man.cgi(8).
+ */
+
+/* Global defaults. */
+
+html {		max-width: 100ex; }
+body {		font-family: Helvetica,Arial,sans-serif; }
+table {		margin-top: 0em;
+		margin-bottom: 0em; }
+td {		vertical-align: top; }
+ul, ol, dl {	margin-top: 0em;
+		margin-bottom: 0em; }
+li, dt {	margin-top: 1em; }
+
+a.selflink {	border-bottom: thin dotted;
+		color: inherit;
+		font: inherit;
+		text-decoration: inherit; }
+* {		clear: both }
+
+/* Search form and search results. */
+
+fieldset {	border: thin solid silver;
+		border-radius: 1em;
+		text-align: center; }
+input[name=expr] {
+		width: 25%; }
+
+table.results {	margin-top: 1em;
+		margin-left: 2em;
+		font-size: smaller; }
+
+/* Header and footer lines. */
+
+table.head {	width: 100%;
+		border-bottom: 1px dotted #808080;
+		margin-bottom: 1em;
+		font-size: smaller; }
+td.head-vol {	text-align: center; }
+td.head-rtitle {
+		text-align: right; }
+span.Nd { }
+
+table.foot {	width: 100%;
+		border-top: 1px dotted #808080;
+		margin-top: 1em;
+		font-size: smaller; }
+td.foot-os {	text-align: right; }
+
+/* Sections and paragraphs. */
+
+div.manual-text {
+		margin-left: 5ex; }
+h1.Sh {		margin-top: 2ex;
+		margin-bottom: 1ex;
+		margin-left: -4ex;
+		font-size: 110%; }
+h2.Ss {		margin-top: 2ex;
+		margin-bottom: 1ex;
+		margin-left: -2ex;
+		font-size: 105%; }
+div.Pp {	margin: 1ex 0ex; }
+a.Sx { }
+a.Xr { }
+
+/* Displays and lists. */
+
+div.Bd { }
+div.D1 {	margin-left: 5ex; }
+
+ul.Bl-bullet {	list-style-type: disc;
+		padding-left: 1em; }
+li.It-bullet { }
+ul.Bl-dash {	list-style-type: none;
+		padding-left: 0em; }
+li.It-dash:before {
+		content: "\2014  "; }
+ul.Bl-item {	list-style-type: none;
+		padding-left: 0em; }
+li.It-item { }
+ul.Bl-compact > li {
+		margin-top: 0ex; }
+
+ol.Bl-enum {	padding-left: 2em; }
+li.It-enum { }
+ol.Bl-compact > li {
+		margin-top: 0ex; }
+
+dl.Bl-diag { }
+dt.It-diag { }
+dd.It-diag {	margin-left: 0ex; }
+b.It-diag {	font-style: normal; }
+dl.Bl-hang { }
+dt.It-hang { }
+dd.It-hang {	margin-left: 10.2ex; }
+dl.Bl-inset { }
+dt.It-inset { }
+dd.It-inset {	margin-left: 0ex; }
+dl.Bl-ohang { }
+dt.It-ohang { }
+dd.It-ohang {	margin-left: 0ex; }
+dl.Bl-tag {	margin-left: 10.2ex; }
+dt.It-tag {	float: left;
+		margin-top: 0ex;
+		margin-left: -10.2ex;
+		padding-right: 2ex;
+		vertical-align: top; }
+dd.It-tag {	clear: right;
+		width: 100%;
+		margin-top: 0ex;
+		margin-left: 0ex;
+		vertical-align: top;
+		overflow: auto; }
+dl.Bl-compact > dt {
+		margin-top: 0ex; }
+
+table.Bl-column { }
+tr.It-column { }
+td.It-column {	margin-top: 1em; }
+table.Bl-compact > tbody > tr > td {
+		margin-top: 0ex; }
+
+cite.Rs {	font-style: normal;
+		font-weight: normal; }
+span.RsA { }
+i.RsB {		font-weight: normal; }
+span.RsC { }
+span.RsD { }
+i.RsI {		font-weight: normal; }
+i.RsJ {		font-weight: normal; }
+span.RsN { }
+span.RsO { }
+span.RsP { }
+span.RsQ { }
+span.RsR { }
+span.RsT {	text-decoration: underline; }
+a.RsU { }
+span.RsV { }
+
+span.eqn { }
+table.tbl { }
+
+/* Semantic markup for command line utilities. */
+
+table.Nm { }
+b.Nm {		font-style: normal; }
+b.Fl {		font-style: normal; }
+b.Cm {		font-style: normal; }
+var.Ar {	font-style: italic;
+		font-weight: normal; }
+span.Op { }
+b.Ic {		font-style: normal; }
+code.Ev {	font-style: normal;
+		font-weight: normal;
+		font-family: monospace; }
+i.Pa {		font-weight: normal; }
+
+/* Semantic markup for function libraries. */
+
+span.Lb { }
+b.In {		font-style: normal; }
+a.In { }
+b.Fd {		font-style: normal; }
+var.Ft {	font-style: italic;
+		font-weight: normal; }
+b.Fn {		font-style: normal; }
+var.Fa {	font-style: italic;
+		font-weight: normal; }
+var.Vt {	font-style: italic;
+		font-weight: normal; }
+var.Va {	font-style: italic;
+		font-weight: normal; }
+code.Dv {	font-style: normal;
+		font-weight: normal;
+		font-family: monospace; }
+code.Er {	font-style: normal;
+		font-weight: normal;
+		font-family: monospace; }
+
+/* Various semantic markup. */
+
+span.An { }
+a.Lk { }
+a.Mt { }
+b.Cd {		font-style: normal; }
+i.Ad {		font-weight: normal; }
+b.Ms {		font-style: normal; }
+span.St { }
+a.Ux { }
+
+/* Physical markup. */
+
+.No {		font-style: normal;
+		font-weight: normal; }
+.Em {		font-style: italic;
+		font-weight: normal; }
+.Sy {		font-style: normal;
+		font-weight: bold; }
+.Li {		font-style: normal;
+		font-weight: normal;
+		font-family: monospace; }

docs/rgbasm.1.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBASM(1)</title>
 </head>
 <body>
@@ -27,7 +27,7 @@
 <table class="Nm">
   <tr>
     <td><b class="Nm" title="Nm">rgbasm</b></td>
-    <td>[<span class="Op"><b class="Fl" title="Fl">-EhVvw</b></span>]
+    <td>[<span class="Op"><b class="Fl" title="Fl">-EhLVvw</b></span>]
       [<span class="Op"><b class="Fl" title="Fl">-b</b>
       <var class="Ar" title="Ar">chars</var></span>]
       [<span class="Op"><b class="Fl" title="Fl">-D</b>
@@ -89,6 +89,13 @@ The <b class="Nm" title="Nm">rgbasm</b> program creates an object file from an
   <dd class="It-tag">Add an include path.</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
+  <dt class="It-tag"><a class="selflink" href="#L"><b class="Fl" title="Fl" id="L">-L</b></a></dt>
+  <dd class="It-tag">Disable the optimization that turns loads of the form
+      <b class="Sy" title="Sy">LD [$FF00+n8],A</b> into the opcode
+      <b class="Sy" title="Sy">LDH [$FF00+n8],A</b> in order to have full
+      control of the result in the final ROM.</dd>
+  <dt class="It-tag">&#x00A0;</dt>
+  <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#M"><b class="Fl" title="Fl" id="M">-M</b></a>
     <var class="Ar" title="Ar">dependfile</var></dt>
   <dd class="It-tag">Print <a class="Xr" title="Xr">make(1)</a> dependencies to
@@ -120,7 +127,11 @@ The <b class="Nm" title="Nm">rgbasm</b> program creates an object file from an
 <h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
 Assembling a basic source file is simple:
 <div class="Pp"></div>
-<div class="D1">$ rgbasm -o bar.o foo.asm</div>
+<div class="Bd" style="margin-left: 5.00ex;">
+<pre class="Li">
+$ rgbasm -o bar.o foo.asm
+</pre>
+</div>
 <div class="Pp"></div>
 The resulting object file is not yet a usable ROM image &#x2014; it must first
   be run through <a class="Xr" title="Xr">rgblink(1)</a> and
@@ -138,7 +149,7 @@ The resulting object file is not yet a usable ROM image &#x2014; it must first
   <a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.</div>
 <table class="foot">
   <tr>
-    <td class="foot-date">January 26, 2018</td>
+    <td class="foot-date">February 24, 2018</td>
     <td class="foot-os">RGBDS Manual</td>
   </tr>
 </table>

docs/rgbds.5.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBDS(5)</title>
 </head>
 <body>
@@ -65,7 +65,9 @@ REPT    NumberOfSymbols   ; Number of symbols defined in this object file.
         LONG    LineNum   ; Line number in the file where the symbol is defined. 
  
         LONG    SectionID ; The section number (of this object file) in which 
-                          ; this symbol is defined. 
+                          ; this symbol is defined. If it doesn't belong to any 
+                          ; specific section (like a constant), this field has 
+                          ; the value -1. 
  
         LONG    Value     ; The symbols value. It's the offset into that 
                           ; symbol's section. 
@@ -121,6 +123,7 @@ REPT NumberOfSections
             BYTE    Type         ; 0 = BYTE patch. 
                                  ; 1 = little endian WORD patch. 
                                  ; 2 = little endian LONG patch. 
+                                 ; 3 = JR offset value BYTE patch. 
  
             LONG    RPNSize      ; Size of the buffer with the RPN. 
                                  ; expression. 

docs/rgbds.7.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBDS(7)</title>
 </head>
 <body>
@@ -26,9 +26,13 @@
 <h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
 To get a working ROM image from a single assembly source file:
 <div class="Pp"></div>
-<div class="D1">$ rgbasm -o bar.o foo.asm</div>
-<div class="D1">$ rgblink -o baz.gb bar.o</div>
-<div class="D1">$ rgbfix -v -p 0 baz.gb</div>
+<div class="Bd" style="margin-left: 5.00ex;">
+<pre class="Li">
+$ rgbasm -o bar.o foo.asm 
+$ rgblink -o baz.gb bar.o 
+$ rgbfix -v -p 0 baz.gb
+</pre>
+</div>
 <h1 class="Sh" title="Sh" id="SEE_ALSO"><a class="selflink" href="#SEE_ALSO">SEE
   ALSO</a></h1>
 <a class="Xr" title="Xr">rgbasm(1)</a>, <a class="Xr" title="Xr">rgbfix(1)</a>,
@@ -52,13 +56,14 @@ To get a working ROM image from a single assembly source file:
   <dt class="It-ohang"></dt>
   <dd class="It-ohang">2017, Bentley's repository is moved to a neutral name. It
       is now maintained by a number of contributors at
-      <a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.
-      2018, codebase relicensed under the MIT license.</dd>
+      <a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.</dd>
+  <dt class="It-ohang"></dt>
+  <dd class="It-ohang">2018, codebase relicensed under the MIT license.</dd>
 </dl>
 </div>
 <table class="foot">
   <tr>
-    <td class="foot-date">January 26, 2018</td>
+    <td class="foot-date">March 7, 2018</td>
     <td class="foot-os">RGBDS Manual</td>
   </tr>
 </table>

docs/rgbfix.1.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBFIX(1)</title>
 </head>
 <body>
@@ -28,6 +28,8 @@
   <tr>
     <td><b class="Nm" title="Nm">rgbfix</b></td>
     <td>[<span class="Op"><b class="Fl" title="Fl">-CcjsVv</b></span>]
+      [<span class="Op"><b class="Fl" title="Fl">-f</b>
+      <var class="Ar" title="Ar">fix_spec</var></span>]
       [<span class="Op"><b class="Fl" title="Fl">-i</b>
       <var class="Ar" title="Ar">game_id</var></span>]
       [<span class="Op"><b class="Fl" title="Fl">-k</b>
@@ -67,6 +69,32 @@ The <b class="Nm" title="Nm">rgbfix</b> program changes headers of Game Boy ROM
       <b class="Fl" title="Fl">-C</b> takes precedence.</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
+  <dt class="It-tag"><a class="selflink" href="#f"><b class="Fl" title="Fl" id="f">-f</b></a>
+    <var class="Ar" title="Ar">fix_spec</var></dt>
+  <dd class="It-tag">Fix certain header values that the Game Boy checks for
+      correctness. Alternatively, intentionally trash these values by writing
+      their binary inverse instead. <var class="Ar" title="Ar">fix_spec</var> is
+      a string containing any combination of the following characters:
+    <div class="Pp"></div>
+    <dl class="Bl-tag Bl-compact" style="margin-left: 5.40ex;">
+      <dt class="It-tag" style="margin-left: -5.40ex;"><a class="selflink" href="#l"><b class="Cm" title="Cm" id="l">l</b></a></dt>
+      <dd class="It-tag">Fix the Nintendo logo
+          (<i class="Ad">0x104</i>&#x2013;<i class="Ad">0x133</i>).</dd>
+      <dt class="It-tag" style="margin-left: -5.40ex;"><a class="selflink" href="#L"><b class="Cm" title="Cm" id="L">L</b></a></dt>
+      <dd class="It-tag">Trash the Nintendo logo.</dd>
+      <dt class="It-tag" style="margin-left: -5.40ex;"><a class="selflink" href="#h"><b class="Cm" title="Cm" id="h">h</b></a></dt>
+      <dd class="It-tag">Fix the header checksum (<i class="Ad">0x14D</i>).</dd>
+      <dt class="It-tag" style="margin-left: -5.40ex;"><a class="selflink" href="#H"><b class="Cm" title="Cm" id="H">H</b></a></dt>
+      <dd class="It-tag">Trash the header checksum.</dd>
+      <dt class="It-tag" style="margin-left: -5.40ex;"><a class="selflink" href="#g"><b class="Cm" title="Cm" id="g">g</b></a></dt>
+      <dd class="It-tag">Fix the global checksum
+          (<i class="Ad">0x14E</i>&#x2013;<i class="Ad">0x14F</i>).</dd>
+      <dt class="It-tag" style="margin-left: -5.40ex;"><a class="selflink" href="#G"><b class="Cm" title="Cm" id="G">G</b></a></dt>
+      <dd class="It-tag">Trash the global checksum.</dd>
+    </dl>
+  </dd>
+  <dt class="It-tag">&#x00A0;</dt>
+  <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#i"><b class="Fl" title="Fl" id="i">-i</b></a>
     <var class="Ar" title="Ar">game_id</var></dt>
   <dd class="It-tag">Set the game ID string
@@ -141,10 +169,8 @@ The <b class="Nm" title="Nm">rgbfix</b> program changes headers of Game Boy ROM
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#v"><b class="Fl" title="Fl" id="v">-v</b></a></dt>
-  <dd class="It-tag">Validate the header and fix checksums: the Nintendo
-      character area (<i class="Ad">0x104</i>&#x2013;<i class="Ad">0x133</i>),
-      the header checksum (<i class="Ad">0x14D</i>), and the global checksum
-      (<i class="Ad">0x14E</i>&#x2013;<i class="Ad">0x14F</i>).</dd>
+  <dd class="It-tag">Equivalent to <b class="Fl" title="Fl">-f</b>
+      <b class="Cm" title="Cm">lhg</b>.</dd>
 </dl>
 <h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
 Most values in the ROM header are only cosmetic. The bare minimum requirements
@@ -179,7 +205,7 @@ The following will duplicate the header (sans global checksum) of the game
   <a class="Lk" title="Lk" href="https://github.com/rednex/rgbds">https://github.com/rednex/rgbds</a>.</div>
 <table class="foot">
   <tr>
-    <td class="foot-date">January 26, 2018</td>
+    <td class="foot-date">March 11, 2018</td>
     <td class="foot-os">RGBDS Manual</td>
   </tr>
 </table>

docs/rgbgfx.1.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBGFX(1)</title>
 </head>
 <body>
@@ -43,7 +43,28 @@
 </table>
 <h1 class="Sh" title="Sh" id="DESCRIPTION"><a class="selflink" href="#DESCRIPTION">DESCRIPTION</a></h1>
 The <b class="Nm" title="Nm">rgbgfx</b> program converts PNG images into the
-  Nintendo Game Boy's planar tile format. The arguments are as follows:
+  Nintendo Game Boy's planar tile format.
+<div style="height: 1.00em;">&#x00A0;</div>
+The resulting colors and their palette indices are determined differently
+  depending on the input PNG file:
+<ul class="Bl-dash">
+  <li class="It-dash">If the file has an embedded palette, that palette's color
+      and order are used.</li>
+  <li class="It-dash">If not, and the image only contains shades of gray, rgbgfx
+      maps them to the indices appropriate for each shade. Any undetermined
+      indices are set to respective default shades of gray. For example: if the
+      bit depth is 2 and the image contains light gray and black, they become
+      the second and fourth colors - and the first and third colors get set to
+      default white and dark gray. If the image has multiple shades that map to
+      the same index, the palette is instead determined as if the image had
+      color.</li>
+  <li class="It-dash">If the image has color (or the grayscale method failed),
+      the colors are sorted from lightest to darkest.</li>
+</ul>
+<div style="height: 1.00em;">&#x00A0;</div>
+The input image may not contain more colors than the selected bit depth allows.
+  Transparent pixels are set to palette index 0.
+<h1 class="Sh" title="Sh" id="ARGUMENTS"><a class="selflink" href="#ARGUMENTS">ARGUMENTS</a></h1>
 <dl class="Bl-tag">
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
@@ -58,14 +79,14 @@ The <b class="Nm" title="Nm">rgbgfx</b> program converts PNG images into the
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#F"><b class="Fl" title="Fl" id="F">-F</b></a></dt>
   <dd class="It-tag">Same as <b class="Fl" title="Fl">-f</b>, but additionally,
-      the input PNG file is fixed to have its parameters match the command
-      line's parameters.</dd>
+      the supplied command line parameters are saved within the PNG and will be
+      loaded and automatically used next time.</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#d"><b class="Fl" title="Fl" id="d">-d</b></a>
     <var class="Ar" title="Ar">depth</var></dt>
-  <dd class="It-tag">The bitdepth of the output image (either 1 or 2). By
-      default, the bitdepth is 2 (two bits per pixel).</dd>
+  <dd class="It-tag">The bit depth of the output image (either 1 or 2). By
+      default, the bit depth is 2 (two bits per pixel).</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#h"><b class="Fl" title="Fl" id="h">-h</b></a></dt>
@@ -79,15 +100,16 @@ The <b class="Nm" title="Nm">rgbgfx</b> program converts PNG images into the
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#p"><b class="Fl" title="Fl" id="p">-p</b></a>
     <var class="Ar" title="Ar">palfile</var></dt>
-  <dd class="It-tag">Raw bytes (8 bytes for two bits per pixel, 4 bytes for one
-      bit per pixel) containing the RGB15 values in the little-endian byte order
-      and then ordered from lightest to darkest.</dd>
+  <dd class="It-tag">Output the image's palette in standard GBC palette format -
+      bytes (8 bytes for two bits per pixel, 4 bytes for one bit per pixel)
+      containing the RGB15 values in little-endian byte order. If the palette
+      contains too few colors, the remaining entries are set to black.</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#P"><b class="Fl" title="Fl" id="P">-P</b></a></dt>
-  <dd class="It-tag">Same as <b class="Fl" title="Fl">-p</b>, but the pallete
-      file output name is made by taking the input filename, removing the file
-      extension, and appending <i class="Pa" title="Pa">.pal</i>.</dd>
+  <dd class="It-tag">Same as <b class="Fl" title="Fl">-p</b>, but the palette
+      file output name is made by taking the input PNG file's filename, removing
+      the file extension, and appending <i class="Pa" title="Pa">.pal</i>.</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#t"><b class="Fl" title="Fl" id="t">-t</b></a>
@@ -120,7 +142,7 @@ The <b class="Nm" title="Nm">rgbgfx</b> program converts PNG images into the
   <dd class="It-tag">Trim the end of the output file by this many tiles.</dd>
 </dl>
 <h1 class="Sh" title="Sh" id="EXAMPLES"><a class="selflink" href="#EXAMPLES">EXAMPLES</a></h1>
-The following will take a PNG file with a bitdepth of 1, 2, or 8, and output
+The following will take a PNG file with a bit depth of 1, 2, or 8, and output
   planar 2bpp data:
 <div class="Pp"></div>
 <div class="D1">$ rgbgfx -o out.2bpp in.png</div>

docs/rgblink.1.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBLINK(1)</title>
 </head>
 <body>
@@ -82,7 +82,7 @@ The arguments are as follows:
     <var class="Ar" title="Ar">overlayfile</var></dt>
   <dd class="It-tag">The ROM image to overlay sections over. When an overlay ROM
       is provided, all sections must be fixed. This may be used to patch an
-      existing binray.</dd>
+      existing binary.</dd>
   <dt class="It-tag">&#x00A0;</dt>
   <dd class="It-tag">&#x00A0;</dd>
   <dt class="It-tag"><a class="selflink" href="#o"><b class="Fl" title="Fl" id="o">-o</b></a>

docs/rgblink.5.html

@@ -8,7 +8,7 @@
     td.head-vol { text-align: center; }
     div.Pp { margin: 1ex 0ex; }
   </style>
-  <link rel="stylesheet" href="manual.css" type="text/css" media="all"/>
+  <link rel="stylesheet" href="mandoc.css" type="text/css" media="all"/>
   <title>RGBLINK(5)</title>
 </head>
 <body>

include/asm/constexpr.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of RGBDS.
+ *
+ * Copyright (c) 1997-2018, Carsten Sorensen and RGBDS contributors.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef RGBDS_ASM_CONSTEXPR_H
+#define RGBDS_ASM_CONSTEXPR_H
+
+#include <stdint.h>
+
+struct ConstExpression {
+	union {
+		int32_t nVal;
+		struct sSymbol *pSym;
+	} u;
+	uint32_t isSym;
+};
+
+void constexpr_Symbol(struct ConstExpression *expr, char *tzSym);
+void constexpr_Number(struct ConstExpression *expr, int32_t i);
+void constexpr_UnaryOp(struct ConstExpression *expr,
+		       int32_t op,
+		       const struct ConstExpression *src);
+void constexpr_BinaryOp(struct ConstExpression *expr,
+			int32_t op,
+			const struct ConstExpression *src1,
+			const struct ConstExpression *src2);
+int32_t constexpr_GetConstantValue(struct ConstExpression *expr);
+
+#endif /* RGBDS_ASM_CONSTEXPR_H */

include/asm/fstack.h

@@ -42,7 +42,7 @@ void fstk_Dump(void);
 void fstk_AddIncludePath(char *s);
 uint32_t fstk_RunMacro(char *s);
 void fstk_RunRept(uint32_t count);
-FILE *fstk_FindFile(char *fname);
+FILE *fstk_FindFile(char *fname, char **incPathUsed);
 int32_t fstk_GetLine(void);
 
 #endif /* RGBDS_ASM_FSTACK_H */

include/asm/main.h

@@ -12,15 +12,16 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#include "extern/stdnoreturn.h"
+#include "helpers.h"
 
 struct sOptions {
-	char gbgfx[4];
 	char binary[2];
-	int32_t fillchar;
-	bool verbose;
-	bool haltnop;
+	char gbgfx[4];
 	bool exportall;
+	int32_t fillchar;
+	bool haltnop;
+	bool optimizeloads;
+	bool verbose;
 	bool warnings; /* True to enable warnings, false to disable them. */
 };
 
@@ -45,7 +46,7 @@ void opt_Parse(char *s);
  * It is also used when the assembler goes into an invalid state (for example,
  * when it fails to allocate memory).
  */
-noreturn void fatalerror(const char *fmt, ...);
+noreturn_ void fatalerror(const char *fmt, ...);
 
 /*
  * Used for errors that make it impossible to assemble correctly, but don't

include/extern/err.h

@@ -17,7 +17,7 @@
 
 #include <stdarg.h>
 
-#include "extern/stdnoreturn.h"
+#include "helpers.h"
 
 #define warn rgbds_warn
 #define vwarn rgbds_vwarn
@@ -34,10 +34,10 @@ void vwarn(const char *fmt, va_list ap);
 void warnx(const char *fmt, ...);
 void vwarnx(const char *fmt, va_list ap);
 
-noreturn void err(int status, const char *fmt, ...);
-noreturn void verr(int status, const char *fmt, va_list ap);
-noreturn void errx(int status, const char *fmt, ...);
-noreturn void verrx(int status, const char *fmt, va_list ap);
+noreturn_ void err(int status, const char *fmt, ...);
+noreturn_ void verr(int status, const char *fmt, va_list ap);
+noreturn_ void errx(int status, const char *fmt, ...);
+noreturn_ void verrx(int status, const char *fmt, va_list ap);
 
 #endif /* ERR_IN_LIBC */
 

include/extern/stdnoreturn.h

@@ -1,29 +0,0 @@
-/*
- * This file is part of RGBDS.
- *
- * Copyright (c) 2014-2018, RGBDS contributors.
- *
- * SPDX-License-Identifier: MIT
- */
-
-#ifndef EXTERN_STDNORETURN_H
-#define EXTERN_STDNORETURN_H
-
-#if __STDC_VERSION__ >= 201112L
-	/* C11 or newer */
-	#define noreturn _Noreturn
-#elif __cplusplus >= 201103L
-	/* C++11 or newer */
-	#define noreturn [[noreturn]]
-#elif __GNUC__ > 2 || (__GNUC__ == 2 && (__GNUC_MINOR__ >= 5))
-	/* GCC 2.5 or newer */
-	#define noreturn __attribute__ ((noreturn))
-#elif _MSC_VER >= 1310
-	/* MS Visual Studio 2003/.NET Framework 1.1 or newer */
-	#define noreturn _declspec(noreturn)
-#else
-	/* Unsupported, but no need to throw a fit */
-	#define noreturn
-#endif
-
-#endif /* EXTERN_STDNORETURN_H */

include/gfx/gb.h

@@ -12,14 +12,15 @@
 #include <stdint.h>
 #include "gfx/main.h"
 
-void png_to_gb(const struct PNGImage png, struct GBImage *gb);
-void output_file(const struct Options opts, const struct GBImage gb);
+void raw_to_gb(const struct RawIndexedImage *raw_image, struct GBImage *gb);
+void output_file(const struct Options *opts, const struct GBImage *gb);
 int get_tile_index(uint8_t *tile, uint8_t **tiles, int num_tiles,
 		   int tile_size);
-void create_tilemap(const struct Options opts, struct GBImage *gb,
+void create_tilemap(const struct Options *opts, struct GBImage *gb,
 		    struct Tilemap *tilemap);
-void output_tilemap_file(const struct Options opts,
-			 const struct Tilemap tilemap);
-void output_palette_file(const struct Options opts, const struct PNGImage png);
+void output_tilemap_file(const struct Options *opts,
+			 const struct Tilemap *tilemap);
+void output_palette_file(const struct Options *opts,
+			 const struct RawIndexedImage *raw_image);
 
 #endif

include/gfx/main.h

@@ -31,6 +31,21 @@ struct Options {
 	char *infile;
 };
 
+struct RGBColor {
+	uint8_t red;
+	uint8_t green;
+	uint8_t blue;
+};
+
+struct ImageOptions {
+	bool horizontal;
+	int trim;
+	char *mapfile;
+	bool mapout;
+	char *palfile;
+	bool palout;
+};
+
 struct PNGImage {
 	png_struct *png;
 	png_info *info;
@@ -39,12 +54,14 @@ struct PNGImage {
 	int height;
 	png_byte depth;
 	png_byte type;
-	bool horizontal;
-	int trim;
-	char *mapfile;
-	bool mapout;
-	char *palfile;
-	bool palout;
+};
+
+struct RawIndexedImage {
+	uint8_t **data;
+	struct RGBColor *palette;
+	int num_colors;
+	int width;
+	int height;
 };
 
 struct GBImage {

include/gfx/makepng.h

@@ -11,10 +11,11 @@
 
 #include "gfx/main.h"
 
-void input_png_file(const struct Options opts, struct PNGImage *img);
-void get_text(struct PNGImage *png);
-void set_text(const struct PNGImage *png);
-void output_png_file(const struct Options opts, const struct PNGImage *png);
-void free_png_data(const struct PNGImage *png);
+struct RawIndexedImage *input_png_file(const struct Options *opts,
+				       struct ImageOptions *png_options);
+void output_png_file(const struct Options *opts,
+		     const struct ImageOptions *png_options,
+		     const struct RawIndexedImage *raw_image);
+void destroy_raw_image(struct RawIndexedImage **raw_image_ptr_ptr);
 
 #endif /* RGBDS_GFX_PNG_H */

include/helpers.h

@@ -0,0 +1,22 @@
+/*
+ * This file is part of RGBDS.
+ *
+ * Copyright (c) 2014-2018, RGBDS contributors.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef HELPERS_H
+#define HELPERS_H
+
+#ifdef __GNUC__
+	/* GCC or compatible */
+	#define noreturn_	__attribute__ ((noreturn))
+	#define unused_		__attribute__ ((unused))
+#else
+	/* Unsupported, but no need to throw a fit */
+	#define noreturn_
+	#define unused_
+#endif
+
+#endif /* HELPERS_H */

include/link/assign.h

@@ -36,8 +36,9 @@ void CreateSymbolTable(void);
 struct sSection *GetSectionByName(const char *name);
 int32_t IsSectionNameInUse(const char *name);
 void SetLinkerscriptName(char *tzLinkerscriptFile);
-int32_t IsSectionSameTypeBankAndFloating(const char *name,
-					 enum eSectionType type, int32_t bank);
+int32_t IsSectionSameTypeBankAndAttrs(const char *name,
+				      enum eSectionType type, int32_t bank,
+				      int32_t org, int32_t align);
 uint32_t AssignSectionAddressAndBankByName(const char *name, uint32_t address,
 					   int32_t bank);
 

include/link/script.h

@@ -11,9 +11,9 @@
 
 #include <stdint.h>
 
-#include "extern/stdnoreturn.h"
+#include "helpers.h"
 
-noreturn void script_fatalerror(const char *fmt, ...);
+noreturn_ void script_fatalerror(const char *fmt, ...);
 
 void script_Parse(const char *path);
 

include/linkdefs.h

@@ -66,7 +66,8 @@ enum eSymbolType {
 enum ePatchType {
 	PATCH_BYTE	= 0x00,
 	PATCH_WORD_L	= 0x01,
-	PATCH_LONG_L	= 0x02
+	PATCH_LONG_L	= 0x02,
+	PATCH_BYTE_JR	= 0x03
 };
 
 #endif /* RGBDS_LINKDEFS_H */

include/version.h

@@ -11,7 +11,7 @@
 
 #define PACKAGE_VERSION_MAJOR (0)
 #define PACKAGE_VERSION_MINOR (3)
-#define PACKAGE_VERSION_PATCH (5)
+#define PACKAGE_VERSION_PATCH (8)
 
 const char *get_package_version_string(void);
 

src/asm/asmy.y

@@ -17,6 +17,7 @@
 
 #include "asm/asm.h"
 #include "asm/charmap.h"
+#include "asm/constexpr.h"
 #include "asm/fstack.h"
 #include "asm/lexer.h"
 #include "asm/main.h"
@@ -28,8 +29,10 @@
 #include "common.h"
 #include "linkdefs.h"
 
+uint32_t nListCountEmpty;
 char *tzNewMacro;
 uint32_t ulNewMacroSize;
+int32_t nPCOffset;
 
 static void bankrangecheck(char *name, uint32_t secttype, int32_t org,
 			   int32_t bank)
@@ -104,18 +107,6 @@ size_t symvaluetostring(char *dest, size_t maxLength, char *sym)
 	return length;
 }
 
-static uint32_t str2int(char *s)
-{
-	uint32_t r = 0;
-
-	while (*s) {
-		r <<= 8;
-		r |= (uint8_t)(*s++);
-	}
-
-	return r;
-}
-
 static uint32_t str2int2(char *s, int32_t length)
 {
 	int32_t i;
@@ -339,8 +330,9 @@ static void if_skip_to_else(void)
 				break;
 
 			case '\"':
-				src++;
+				src += 2;
 				inString = false;
+				break;
 
 			default:
 				src++;
@@ -447,15 +439,15 @@ static void updateUnion(void)
 	char tzString[MAXSTRLEN + 1];
 	struct Expression sVal;
 	int32_t nConstValue;
+	struct ConstExpression sConstExpr;
 }
 
 %type	<sVal>		relocconst
-%type	<nConstValue>	const
+%type	<sConstExpr>	const
 %type	<nConstValue>	uconst
 %type	<nConstValue>	const_3bit
 %type	<sVal>		const_8bit
 %type	<sVal>		const_16bit
-%type	<sVal>		const_PCrel
 %type	<nConstValue>	sectiontype
 
 %type	<tzString>	string
@@ -463,38 +455,38 @@ static void updateUnion(void)
 %token	<nConstValue>	T_NUMBER
 %token	<tzString>	T_STRING
 
-%left	T_OP_LOGICNOT
-%left	T_OP_LOGICOR T_OP_LOGICAND T_OP_LOGICEQU
-%left	T_OP_LOGICGT T_OP_LOGICLT T_OP_LOGICGE T_OP_LOGICLE T_OP_LOGICNE
-%left	T_OP_ADD T_OP_SUB
-%left	T_OP_OR T_OP_XOR T_OP_AND
-%left	T_OP_SHL T_OP_SHR
-%left	T_OP_MUL T_OP_DIV T_OP_MOD
-%left	T_OP_NOT
-%left	T_OP_DEF
-%left	T_OP_BANK T_OP_ALIGN
-%left	T_OP_SIN
-%left	T_OP_COS
-%left	T_OP_TAN
-%left	T_OP_ASIN
-%left	T_OP_ACOS
-%left	T_OP_ATAN
-%left	T_OP_ATAN2
-%left	T_OP_FDIV
-%left	T_OP_FMUL
-%left	T_OP_ROUND
-%left	T_OP_CEIL
-%left	T_OP_FLOOR
+%left	<nConstValue>	T_OP_LOGICNOT
+%left	<nConstValue>	T_OP_LOGICOR T_OP_LOGICAND T_OP_LOGICEQU
+%left	<nConstValue>	T_OP_LOGICGT T_OP_LOGICLT T_OP_LOGICGE T_OP_LOGICLE T_OP_LOGICNE
+%left	<nConstValue>	T_OP_ADD T_OP_SUB
+%left	<nConstValue>	T_OP_OR T_OP_XOR T_OP_AND
+%left	<nConstValue>	T_OP_SHL T_OP_SHR
+%left	<nConstValue>	T_OP_MUL T_OP_DIV T_OP_MOD
+%left	<nConstValue>	T_OP_NOT
+%left	<nConstValue>	T_OP_DEF
+%left	<nConstValue>	T_OP_BANK T_OP_ALIGN
+%left	<nConstValue>	T_OP_SIN
+%left	<nConstValue>	T_OP_COS
+%left	<nConstValue>	T_OP_TAN
+%left	<nConstValue>	T_OP_ASIN
+%left	<nConstValue>	T_OP_ACOS
+%left	<nConstValue>	T_OP_ATAN
+%left	<nConstValue>	T_OP_ATAN2
+%left	<nConstValue>	T_OP_FDIV
+%left	<nConstValue>	T_OP_FMUL
+%left	<nConstValue>	T_OP_ROUND
+%left	<nConstValue>	T_OP_CEIL
+%left	<nConstValue>	T_OP_FLOOR
 
-%token	T_OP_HIGH T_OP_LOW
+%token	<nConstValue>	T_OP_HIGH T_OP_LOW
 
-%left	T_OP_STRCMP
-%left	T_OP_STRIN
-%left	T_OP_STRSUB
-%left	T_OP_STRLEN
-%left	T_OP_STRCAT
-%left	T_OP_STRUPR
-%left	T_OP_STRLWR
+%left	<nConstValue>	T_OP_STRCMP
+%left	<nConstValue>	T_OP_STRIN
+%left	<nConstValue>	T_OP_STRSUB
+%left	<nConstValue>	T_OP_STRLEN
+%left	<nConstValue>	T_OP_STRCAT
+%left	<nConstValue>	T_OP_STRUPR
+%left	<nConstValue>	T_OP_STRLWR
 
 %left	NEG /* negation -- unary minus */
 
@@ -504,7 +496,7 @@ static void updateUnion(void)
 %token	<tzSym> T_POP_SET
 %token	<tzSym> T_POP_EQUS
 
-%token	T_POP_INCLUDE T_POP_PRINTF T_POP_PRINTT T_POP_PRINTV
+%token	T_POP_INCLUDE T_POP_PRINTF T_POP_PRINTT T_POP_PRINTV T_POP_PRINTI
 %token	T_POP_IF T_POP_ELIF T_POP_ELSE T_POP_ENDC
 %token	T_POP_IMPORT T_POP_EXPORT T_POP_GLOBAL
 %token	T_POP_DB T_POP_DS T_POP_DW T_POP_DL
@@ -580,10 +572,13 @@ asmfile		: lines;
 
 /* Note: The lexer adds '\n' at the end of the input */
 lines		: /* empty */
-		| lines line '\n' {
-			nLineNo += 1;
-			nTotalLines += 1;
-		}
+		| lines {
+				nListCountEmpty = 0;
+				nPCOffset = 1;
+			} line '\n' {
+				nLineNo += 1;
+				nTotalLines += 1;
+			}
 ;
 
 line		: label
@@ -648,6 +643,7 @@ simple_pseudoop : include
 		| printf
 		| printt
 		| printv
+		| printi
 		| if
 		| elif
 		| else
@@ -655,9 +651,9 @@ simple_pseudoop : include
 		| import
 		| export
 		| global
-		| db
-		| dw
-		| dl
+		| { nPCOffset = 0; } db
+		| { nPCOffset = 0; } dw
+		| { nPCOffset = 0; } dl
 		| ds
 		| section
 		| rsreset
@@ -802,16 +798,28 @@ ds		: T_POP_DS uconst
 		}
 ;
 
-db		: T_POP_DB constlist_8bit_entry comma constlist_8bit
-		| T_POP_DB constlist_8bit_entry_single
+db		: T_POP_DB constlist_8bit_entry comma constlist_8bit {
+			if ((nPass == 1) && (nListCountEmpty > 0)) {
+				warning("Empty entry in list of 8-bit elements (treated as 0).");
+			}
+		}
+		| T_POP_DB constlist_8bit_entry
 ;
 
-dw		: T_POP_DW constlist_16bit_entry comma constlist_16bit
-		| T_POP_DW constlist_16bit_entry_single
+dw		: T_POP_DW constlist_16bit_entry comma constlist_16bit {
+			if ((nPass == 1) && (nListCountEmpty > 0)) {
+				warning("Empty entry in list of 16-bit elements (treated as 0).");
+			}
+		}
+		| T_POP_DW constlist_16bit_entry
 ;
 
-dl		: T_POP_DL constlist_32bit_entry comma constlist_32bit
-		| T_POP_DL constlist_32bit_entry_single
+dl		: T_POP_DL constlist_32bit_entry comma constlist_32bit {
+			if ((nPass == 1) && (nListCountEmpty > 0)) {
+				warning("Empty entry in list of 32-bit elements (treated as 0).");
+			}
+		}
+		| T_POP_DL constlist_32bit_entry
 ;
 
 purge		: T_POP_PURGE {
@@ -877,13 +885,13 @@ global_list_entry : T_ID
 
 equ		: T_LABEL T_POP_EQU const
 		{
-			sym_AddEqu($1, $3);
+			sym_AddEqu($1, constexpr_GetConstantValue(&$3));
 		}
 ;
 
 set		: T_LABEL T_POP_SET const
 		{
-			sym_AddSet($1, $3);
+			sym_AddSet($1, constexpr_GetConstantValue(&$3));
 		}
 ;
 
@@ -912,7 +920,7 @@ charmap		: T_POP_CHARMAP string comma string
 		}
 		| T_POP_CHARMAP string comma const
 		{
-			if (charmap_Add($2, $4 & 0xFF) == -1) {
+			if (charmap_Add($2, constexpr_GetConstantValue(&$4) & 0xFF) == -1) {
 				fprintf(stderr, "Error parsing charmap. Either you've added too many (%i), or the input character length is too long (%i)' : %s\n", MAXCHARMAPS, CHARMAPLENGTH, strerror(errno));
 				yyerror("Error parsing charmap.");
 			}
@@ -929,21 +937,28 @@ printt		: T_POP_PRINTT string
 printv		: T_POP_PRINTV const
 		{
 			if (nPass == 1)
-				printf("$%X", $2);
+				printf("$%X", constexpr_GetConstantValue(&$2));
+		}
+;
+
+printi		: T_POP_PRINTI const
+		{
+			if (nPass == 1)
+				printf("%d", constexpr_GetConstantValue(&$2));
 		}
 ;
 
 printf		: T_POP_PRINTF const
 		{
 			if (nPass == 1)
-				math_Print($2);
+				math_Print(constexpr_GetConstantValue(&$2));
 		}
 ;
 
 if		: T_POP_IF const
 		{
 			nIFDepth++;
-			if (!$2) {
+			if (!constexpr_GetConstantValue(&$2)) {
 				/*
 				 * Continue parsing after ELSE, or at ELIF or
 				 * ENDC keyword.
@@ -975,7 +990,7 @@ elif		: T_POP_ELIF const
 				 */
 				skipElif = true;
 
-				if (!$2) {
+				if (!constexpr_GetConstantValue(&$2)) {
 					/*
 					 * Continue parsing after ELSE, or at
 					 * ELIF or ENDC keyword.
@@ -1007,10 +1022,11 @@ endc		: T_POP_ENDC
 
 const_3bit	: const
 		{
-			if (($1 < 0) || ($1 > 7))
+			int32_t value = constexpr_GetConstantValue(&$1);
+			if ((value < 0) || (value > 7))
 				yyerror("Immediate value must be 3-bit");
 			else
-				$$ = $1 & 0x7;
+				$$ = value & 0x7;
 		}
 ;
 
@@ -1021,26 +1037,7 @@ constlist_8bit	: constlist_8bit_entry
 constlist_8bit_entry : /* empty */
 		{
 			out_Skip(1);
-			if (nPass == 1)
-				warning("Empty entry in list of 8-bit elements (treated as 0).");
-		}
-		| const_8bit
-		{
-			out_RelByte(&$1);
-		}
-		| string
-		{
-			char *s = $1;
-			int32_t length = charmap_Convert(&s);
-
-			out_AbsByteGroup(s, length);
-			free(s);
-		}
-;
-
-constlist_8bit_entry_single : /* empty */
-		{
-			out_Skip(1);
+			nListCountEmpty++;
 		}
 		| const_8bit
 		{
@@ -1063,18 +1060,7 @@ constlist_16bit : constlist_16bit_entry
 constlist_16bit_entry : /* empty */
 		{
 			out_Skip(2);
-			if (nPass == 1)
-				warning("Empty entry in list of 16-bit elements (treated as 0).");
-		}
-		| const_16bit
-		{
-			out_RelWord(&$1);
-		}
-;
-
-constlist_16bit_entry_single : /* empty */
-		{
-			out_Skip(2);
+			nListCountEmpty++;
 		}
 		| const_16bit
 		{
@@ -1089,8 +1075,7 @@ constlist_32bit : constlist_32bit_entry
 constlist_32bit_entry : /* empty */
 		{
 			out_Skip(4);
-			if (nPass == 1)
-				warning("Empty entry in list of 32-bit elements (treated as 0).");
+			nListCountEmpty++;
 		}
 		| relocconst
 		{
@@ -1098,24 +1083,6 @@ constlist_32bit_entry : /* empty */
 		}
 ;
 
-constlist_32bit_entry_single : /* empty */
-		{
-			out_Skip(4);
-		}
-		| relocconst
-		{
-			out_RelLong(&$1);
-		}
-;
-
-const_PCrel	: relocconst
-		{
-			if (!rpn_isPCRelative(&$1))
-				yyerror("Expression must be PC-relative");
-			$$ = $1;
-		}
-;
-
 const_8bit	: relocconst
 		{
 			if( (!rpn_isReloc(&$1)) && (($1.nVal < -128) || ($1.nVal > 255)) )
@@ -1135,8 +1102,39 @@ const_16bit	: relocconst
 
 relocconst	: T_ID
 		{
-			rpn_Symbol(&$$, $1);
-			$$.nVal = sym_GetValue($1);
+			/*
+			 * The value of @ needs to be evaluated by the linker,
+			 * it can only be calculated by the assembler in very
+			 * few cases (when the base address of a section is
+			 * known).
+			 *
+			 * '@' is a bit special in that it means different
+			 * things depending on when it is used:
+			 *
+			 * - JR/LD/ADD/etc: It refers to the first byte of the
+			 *   instruction (1 byte offset relative to the value
+			 *   stored in the ROM).
+			 * - DB/DW/DL: It refers to the address of the value
+			 *   that is being saved (0 byte offset relative to the
+			 *   value stored in the ROM.
+			 *
+			 * This offset must be added whenever '@' is added to a
+			 * RPN expression so that the linker can calculate the
+			 * correct result of any expression that uses '@'.
+			 */
+			if ((strcmp($1, "@") == 0) && (nPCOffset != 0)) {
+				struct Expression sTemp, sOffset;
+
+				rpn_Symbol(&sTemp, $1);
+				sTemp.nVal = sym_GetValue($1);
+
+				rpn_Number(&sOffset, nPCOffset);
+
+				rpn_SUB(&$$, &sTemp, &sOffset);
+			} else {
+				rpn_Symbol(&$$, $1);
+				$$.nVal = sym_GetValue($1);
+			}
 		}
 		| T_NUMBER
 		{
@@ -1195,18 +1193,60 @@ relocconst	: T_ID
 			rpn_Number(&$$, sym_isConstDefined($4));
 			oDontExpandStrings = false;
 		}
-		| T_OP_ROUND '(' const ')'		{ rpn_Number(&$$, math_Round($3)); }
-		| T_OP_CEIL '(' const ')'		{ rpn_Number(&$$, math_Ceil($3)); }
-		| T_OP_FLOOR '(' const ')'		{ rpn_Number(&$$, math_Floor($3)); }
-		| T_OP_FDIV '(' const comma const ')'	{ rpn_Number(&$$, math_Div($3, $5)); }
-		| T_OP_FMUL '(' const comma const ')'	{ rpn_Number(&$$, math_Mul($3, $5)); }
-		| T_OP_SIN '(' const ')'		{ rpn_Number(&$$, math_Sin($3)); }
-		| T_OP_COS '(' const ')'		{ rpn_Number(&$$, math_Cos($3)); }
-		| T_OP_TAN '(' const ')'		{ rpn_Number(&$$, math_Tan($3)); }
-		| T_OP_ASIN '(' const ')'		{ rpn_Number(&$$, math_ASin($3)); }
-		| T_OP_ACOS '(' const ')'		{ rpn_Number(&$$, math_ACos($3)); }
-		| T_OP_ATAN '(' const ')'		{ rpn_Number(&$$, math_ATan($3)); }
-		| T_OP_ATAN2 '(' const comma const ')'	{ rpn_Number(&$$, math_ATan2($3, $5)); }
+		| T_OP_ROUND '(' const ')'
+		{
+			rpn_Number(&$$, math_Round(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_CEIL '(' const ')'
+		{
+			rpn_Number(&$$, math_Ceil(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_FLOOR '(' const ')'
+		{
+			rpn_Number(&$$, math_Floor(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_FDIV '(' const comma const ')'
+		{
+			rpn_Number(&$$,
+				   math_Div(constexpr_GetConstantValue(&$3),
+					    constexpr_GetConstantValue(&$5)));
+		}
+		| T_OP_FMUL '(' const comma const ')'
+		{
+			rpn_Number(&$$,
+				   math_Mul(constexpr_GetConstantValue(&$3),
+					    constexpr_GetConstantValue(&$5)));
+		}
+		| T_OP_SIN '(' const ')'
+		{
+			rpn_Number(&$$, math_Sin(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_COS '(' const ')'
+		{
+			rpn_Number(&$$, math_Cos(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_TAN '(' const ')'
+		{
+			rpn_Number(&$$, math_Tan(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_ASIN '(' const ')'
+		{
+			rpn_Number(&$$, math_ASin(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_ACOS '(' const ')'
+		{
+			rpn_Number(&$$, math_ACos(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_ATAN '(' const ')'
+		{
+			rpn_Number(&$$, math_ATan(constexpr_GetConstantValue(&$3)));
+		}
+		| T_OP_ATAN2 '(' const comma const ')'
+		{
+			rpn_Number(&$$,
+				   math_ATan2(constexpr_GetConstantValue(&$3),
+					      constexpr_GetConstantValue(&$5)));
+		}
 		| T_OP_STRCMP '(' string comma string ')'
 		{
 			rpn_Number(&$$, strcmp($3, $5));
@@ -1226,111 +1266,115 @@ relocconst	: T_ID
 
 uconst		: const
 		{
-			if ($1 < 0)
-				fatalerror("Constant mustn't be negative: %d", $1);
-			$$ = $1;
+			int32_t value = constexpr_GetConstantValue(&$1);
+			if (value < 0)
+				fatalerror("Constant mustn't be negative: %d", value);
+			$$ = value;
 		}
 ;
 
-const		: T_ID					{ $$ = sym_GetConstantValue($1); }
-		| T_NUMBER				{ $$ = $1; }
-		| string				{ $$ = str2int($1); }
-		| T_OP_LOGICNOT const %prec NEG		{ $$ = !$2; }
-		| const T_OP_LOGICOR const		{ $$ = $1 || $3; }
-		| const T_OP_LOGICAND const		{ $$ = $1 && $3; }
-		| const T_OP_LOGICEQU const		{ $$ = $1 == $3; }
-		| const T_OP_LOGICGT const		{ $$ = $1 > $3; }
-		| const T_OP_LOGICLT const		{ $$ = $1 < $3; }
-		| const T_OP_LOGICGE const		{ $$ = $1 >= $3; }
-		| const T_OP_LOGICLE const		{ $$ = $1 <= $3; }
-		| const T_OP_LOGICNE const		{ $$ = $1 != $3; }
-		| const T_OP_ADD const			{ $$ = $1 + $3; }
-		| const T_OP_SUB const			{ $$ = $1 - $3; }
-		| T_ID  T_OP_SUB T_ID
+const		: T_ID					{ constexpr_Symbol(&$$, $1); }
+		| T_NUMBER				{ constexpr_Number(&$$, $1); }
+		| T_OP_HIGH '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_LOW '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| string
 		{
-			if (sym_IsRelocDiffDefined($1, $3) == 0)
-				fatalerror("'%s - %s' not defined.", $1, $3);
-			$$ = sym_GetDefinedValue($1) - sym_GetDefinedValue($3);
+			char *s = $1;
+			int32_t length = charmap_Convert(&s);
+			constexpr_Number(&$$, str2int2(s, length));
+			free(s);
 		}
-		| const T_OP_XOR const			{ $$ = $1 ^ $3; }
-		| const T_OP_OR const			{ $$ = $1 | $3; }
-		| const T_OP_AND const			{ $$ = $1 & $3; }
-		| const T_OP_SHL const			{ $$ = $1 << $3; }
-		| const T_OP_SHR const			{ $$ = $1 >> $3; }
-		| const T_OP_MUL const			{ $$ = $1 * $3; }
-		| const T_OP_DIV const
-		{
-			if ($3 == 0)
-				fatalerror("division by zero");
-			$$ = $1 / $3;
-		}
-		| const T_OP_MOD const
-		{
-			if ($3 == 0)
-				fatalerror("division by zero");
-			$$ = $1 % $3;
-		}
-		| T_OP_ADD const %prec NEG		{ $$ = +$2; }
-		| T_OP_SUB const %prec NEG		{ $$ = -$2; }
-		| T_OP_NOT const %prec NEG		{ $$ = ~$2; }
-		| T_OP_ROUND '(' const ')'		{ $$ = math_Round($3); }
-		| T_OP_CEIL '(' const ')'		{ $$ = math_Ceil($3); }
-		| T_OP_FLOOR '(' const ')'		{ $$ = math_Floor($3); }
-		| T_OP_FDIV '(' const comma const ')'	{ $$ = math_Div($3,$5); }
-		| T_OP_FMUL '(' const comma const ')'	{ $$ = math_Mul($3,$5); }
-		| T_OP_SIN '(' const ')'		{ $$ = math_Sin($3); }
-		| T_OP_COS '(' const ')'		{ $$ = math_Cos($3); }
-		| T_OP_TAN '(' const ')'		{ $$ = math_Tan($3); }
-		| T_OP_ASIN '(' const ')'		{ $$ = math_ASin($3); }
-		| T_OP_ACOS '(' const ')'		{ $$ = math_ACos($3); }
-		| T_OP_ATAN '(' const ')'		{ $$ = math_ATan($3); }
-		| T_OP_ATAN2 '(' const comma const ')'	{ $$ = math_ATan2($3,$5); }
+		| T_OP_LOGICNOT const %prec NEG		{ constexpr_UnaryOp(&$$, $1, &$2); }
+		| const T_OP_LOGICOR const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICAND const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICEQU const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICGT const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICLT const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICGE const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICLE const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_LOGICNE const		{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_ADD const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_SUB const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_XOR const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_OR const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_AND const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_SHL const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_SHR const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_MUL const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_DIV const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| const T_OP_MOD const			{ constexpr_BinaryOp(&$$, $2, &$1, &$3); }
+		| T_OP_ADD const %prec NEG		{ constexpr_UnaryOp(&$$, $1, &$2); }
+		| T_OP_SUB const %prec NEG		{ constexpr_UnaryOp(&$$, $1, &$2); }
+		| T_OP_NOT const %prec NEG		{ constexpr_UnaryOp(&$$, $1, &$2); }
+		| T_OP_ROUND '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_CEIL '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_FLOOR '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_FDIV '(' const comma const ')'	{ constexpr_BinaryOp(&$$, $1, &$3, &$5); }
+		| T_OP_FMUL '(' const comma const ')'	{ constexpr_BinaryOp(&$$, $1, &$3, &$5); }
+		| T_OP_SIN '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_COS '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_TAN '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_ASIN '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_ACOS '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_ATAN '(' const ')'		{ constexpr_UnaryOp(&$$, $1, &$3); }
+		| T_OP_ATAN2 '(' const comma const ')'	{ constexpr_BinaryOp(&$$, $1, &$3, &$5); }
 		| T_OP_DEF {
 				oDontExpandStrings = true;
 			} '(' T_ID ')'
 		{
-			$$ = sym_isConstDefined($4);
+			constexpr_Number(&$$, sym_isConstDefined($4));
 			oDontExpandStrings = false;
 		}
 		| T_OP_STRCMP '(' string comma string ')'
 		{
-			$$ = strcmp($3, $5);
+			constexpr_Number(&$$, strcmp($3, $5));
 		}
 		| T_OP_STRIN '(' string comma string ')'
 		{
 			char *p = strstr($3, $5);
 
 			if (p != NULL)
-				$$ = p - $3 + 1;
+				constexpr_Number(&$$, p - $3 + 1);
 			else
-				$$ = 0;
+				constexpr_Number(&$$, 0);
 		}
-		| T_OP_STRLEN '(' string ')'		{ $$ = strlen($3); }
+		| T_OP_STRLEN '(' string ')'		{ constexpr_Number(&$$, strlen($3)); }
 		| '(' const ')'				{ $$ = $2; }
 ;
 
 string		: T_STRING
 		{
-			strcpy($$, $1);
+			if (snprintf($$, MAXSTRLEN + 1, "%s", $1) > MAXSTRLEN)
+				warning("String is too long '%s'", $1);
 		}
 		| T_OP_STRSUB '(' string comma uconst comma uconst ')'
 		{
-			strncpy($$, $3 + $5 - 1, $7);
-			$$[$7] = 0;
+			uint32_t len = $7;
+			if (len > MAXSTRLEN) {
+				warning("STRSUB: Length too big: %u", len);
+				len = MAXSTRLEN;
+			}
+
+			if (snprintf($$, len + 1, "%s", $3 + $5 - 1) > MAXSTRLEN)
+				warning("STRSUB: String too long '%s'", $$);
 		}
 		| T_OP_STRCAT '(' string comma string ')'
 		{
-			strcpy($$, $3);
-			strcat($$, $5);
+			if (snprintf($$, MAXSTRLEN + 1, "%s%s", $3, $5) > MAXSTRLEN)
+				warning("STRCAT: String too long '%s%s'", $3, $5);
 		}
 		| T_OP_STRUPR '(' string ')'
 		{
-			strcpy($$, $3);
+			if (snprintf($$, MAXSTRLEN + 1, "%s", $3) > MAXSTRLEN)
+				warning("STRUPR: String too long '%s'", $3);
+
 			upperstring($$);
 		}
 		| T_OP_STRLWR '(' string ')'
 		{
-			strcpy($$, $3);
+			if (snprintf($$, MAXSTRLEN + 1, "%s", $3) > MAXSTRLEN)
+				warning("STRUPR: String too long '%s'", $3);
+
 			lowerstring($$);
 		}
 ;
@@ -1602,12 +1646,12 @@ z80_jp		: T_Z80_JP const_16bit
 		}
 ;
 
-z80_jr		: T_Z80_JR const_PCrel
+z80_jr		: T_Z80_JR const_16bit
 		{
 			out_AbsByte(0x18);
 			out_PCRelByte(&$2);
 		}
-		| T_Z80_JR ccode comma const_PCrel
+		| T_Z80_JR ccode comma const_16bit
 		{
 			out_AbsByte(0x20 | ($2 << 3));
 			out_PCRelByte(&$4);
@@ -1668,6 +1712,14 @@ z80_ldio	: T_Z80_LDIO T_MODE_A comma op_mem_ind
 			$2.nVal &= 0xFF;
 			out_RelByte(&$2);
 		}
+		| T_Z80_LDIO T_MODE_A comma T_MODE_C_IND
+		{
+			out_AbsByte(0xF2);
+		}
+		| T_Z80_LDIO T_MODE_C_IND comma T_MODE_A
+		{
+			out_AbsByte(0xE2);
+		}
 ;
 
 z80_ld		: z80_ld_mem
@@ -1716,7 +1768,8 @@ z80_ld_mem	: T_Z80_LD op_mem_ind comma T_MODE_SP
 		}
 		| T_Z80_LD op_mem_ind comma T_MODE_A
 		{
-			if ((!rpn_isReloc(&$2)) && ($2.nVal >= 0xFF00)) {
+			if (CurrentOptions.optimizeloads &&
+			    (!rpn_isReloc(&$2)) && ($2.nVal >= 0xFF00)) {
 				out_AbsByte(0xE0);
 				out_AbsByte($2.nVal & 0xFF);
 			} else {
@@ -1769,7 +1822,8 @@ z80_ld_a	: T_Z80_LD reg_r comma T_MODE_C_IND
 		| T_Z80_LD reg_r comma op_mem_ind
 		{
 			if ($2 == REG_A) {
-				if ((!rpn_isReloc(&$4)) && ($4.nVal >= 0xFF00)) {
+				if (CurrentOptions.optimizeloads &&
+				    (!rpn_isReloc(&$4)) && ($4.nVal >= 0xFF00)) {
 					out_AbsByte(0xF0);
 					out_AbsByte($4.nVal & 0xFF);
 				} else {

src/asm/charmap.c

@@ -32,12 +32,10 @@ int32_t readUTF8Char(char *dest, char *src)
 
 		dest[i] = src[i];
 
-		i++;
 		if (state == 0) {
-			dest[i] = '\0';
+			dest[++i] = '\0';
 			return i;
 		}
-		dest[i] = src[i];
 	}
 }
 

src/asm/constexpr.c

@@ -0,0 +1,231 @@
+/*
+ * This file is part of RGBDS.
+ *
+ * Copyright (c) 1997-2018, Carsten Sorensen and RGBDS contributors.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "asm/asm.h"
+#include "asm/constexpr.h"
+#include "asm/lexer.h"
+#include "asm/main.h"
+#include "asm/mymath.h"
+#include "asm/rpn.h"
+#include "asm/symbol.h"
+
+#include "asmy.h"
+
+void constexpr_Symbol(struct ConstExpression *expr, char *tzSym)
+{
+	if (!sym_isConstant(tzSym)) {
+		struct sSymbol *pSym = sym_FindSymbol(tzSym);
+
+		if (pSym != NULL) {
+			expr->u.pSym = pSym;
+			expr->isSym = 1;
+		} else {
+			fatalerror("'%s' not defined", tzSym);
+		}
+	} else {
+		constexpr_Number(expr, sym_GetConstantValue(tzSym));
+	}
+}
+
+void constexpr_Number(struct ConstExpression *expr, int32_t i)
+{
+	expr->u.nVal = i;
+	expr->isSym = 0;
+}
+
+void constexpr_UnaryOp(struct ConstExpression *expr,
+		       int32_t op,
+		       const struct ConstExpression *src)
+{
+	if (src->isSym)
+		fatalerror("Non-constant operand in constant expression");
+
+	int32_t value = src->u.nVal;
+	int32_t result = 0;
+
+	switch (op) {
+	case T_OP_HIGH:
+		result = (value >> 8) & 0xFF;
+		break;
+	case T_OP_LOW:
+		result = value & 0xFF;
+		break;
+	case T_OP_LOGICNOT:
+		result = !value;
+		break;
+	case T_OP_ADD:
+		result = value;
+		break;
+	case T_OP_SUB:
+		result = -value;
+		break;
+	case T_OP_NOT:
+		result = ~value;
+		break;
+	case T_OP_ROUND:
+		result = math_Round(value);
+		break;
+	case T_OP_CEIL:
+		result = math_Ceil(value);
+		break;
+	case T_OP_FLOOR:
+		result = math_Floor(value);
+		break;
+	case T_OP_SIN:
+		result = math_Sin(value);
+		break;
+	case T_OP_COS:
+		result = math_Cos(value);
+		break;
+	case T_OP_TAN:
+		result = math_Tan(value);
+		break;
+	case T_OP_ASIN:
+		result = math_ASin(value);
+		break;
+	case T_OP_ACOS:
+		result = math_ACos(value);
+		break;
+	case T_OP_ATAN:
+		result = math_ATan(value);
+		break;
+	default:
+		fatalerror("Unknown unary op");
+	}
+
+	constexpr_Number(expr, result);
+}
+
+void constexpr_BinaryOp(struct ConstExpression *expr,
+			int32_t op,
+			const struct ConstExpression *src1,
+			const struct ConstExpression *src2)
+{
+	int32_t value1;
+	int32_t value2;
+	int32_t result = 0;
+
+	if (op == T_OP_SUB && src1->isSym && src2->isSym) {
+		char *symName1 = src1->u.pSym->tzName;
+		char *symName2 = src2->u.pSym->tzName;
+
+		if (!sym_IsRelocDiffDefined(symName1, symName2))
+			fatalerror("'%s - %s' not defined", symName1, symName2);
+		value1 = sym_GetDefinedValue(symName1);
+		value2 = sym_GetDefinedValue(symName2);
+		result = value1 - value2;
+	} else if (src1->isSym || src2->isSym) {
+		fatalerror("Non-constant operand in constant expression");
+	} else {
+		value1 = src1->u.nVal;
+		value2 = src2->u.nVal;
+
+		switch (op) {
+		case T_OP_LOGICOR:
+			result = value1 || value2;
+			break;
+		case T_OP_LOGICAND:
+			result = value1 && value2;
+			break;
+		case T_OP_LOGICEQU:
+			result = value1 == value2;
+			break;
+		case T_OP_LOGICGT:
+			result = value1 > value2;
+			break;
+		case T_OP_LOGICLT:
+			result = value1 < value2;
+			break;
+		case T_OP_LOGICGE:
+			result = value1 >= value2;
+			break;
+		case T_OP_LOGICLE:
+			result = value1 <= value2;
+			break;
+		case T_OP_LOGICNE:
+			result = value1 != value2;
+			break;
+		case T_OP_ADD:
+			result = value1 + value2;
+			break;
+		case T_OP_SUB:
+			result = value1 - value2;
+			break;
+		case T_OP_XOR:
+			result = value1 ^ value2;
+			break;
+		case T_OP_OR:
+			result = value1 | value2;
+			break;
+		case T_OP_AND:
+			result = value1 & value2;
+			break;
+		case T_OP_SHL:
+			if (value1 < 0)
+				warning("Left shift of negative value: %d",
+					value1);
+
+			if (value2 < 0)
+				fatalerror("Shift by negative value: %d",
+					   value2);
+			else if (value2 >= 32)
+				fatalerror("Shift by too big value: %d",
+					   value2);
+
+			result = value1 << value2;
+			break;
+		case T_OP_SHR:
+			if (value2 < 0)
+				fatalerror("Shift by negative value: %d",
+					   value2);
+			else if (value2 >= 32)
+				fatalerror("Shift by too big value: %d",
+					   value2);
+
+			result = value1 >> value2;
+			break;
+		case T_OP_MUL:
+			result = value1 * value2;
+			break;
+		case T_OP_DIV:
+			if (value2 == 0)
+				fatalerror("Division by zero");
+			result = value1 / value2;
+			break;
+		case T_OP_MOD:
+			if (value2 == 0)
+				fatalerror("Division by zero");
+			result = value1 % value2;
+			break;
+		case T_OP_FDIV:
+			result = math_Div(value1, value2);
+			break;
+		case T_OP_FMUL:
+			result = math_Mul(value1, value2);
+			break;
+		case T_OP_ATAN2:
+			result = math_ATan2(value1, value2);
+			break;
+		default:
+			fatalerror("Unknown binary op");
+		}
+	}
+
+	constexpr_Number(expr, result);
+}
+
+int32_t constexpr_GetConstantValue(struct ConstExpression *expr)
+{
+	if (expr->isSym)
+		fatalerror("Non-constant expression");
+	return expr->u.nVal;
+}

src/asm/fstack.c

@@ -87,6 +87,8 @@ static void pushcontext(void)
 		(*ppFileStack)->nREPTBlockSize = nCurrentREPTBlockSize;
 		(*ppFileStack)->nREPTBlockCount = nCurrentREPTBlockCount;
 		break;
+	default:
+		fatalerror("%s: Internal error.", __func__);
 	}
 
 	nLineNo = 0;
@@ -152,6 +154,8 @@ static int32_t popcontext(void)
 		nCurrentREPTBlockSize = pLastFile->nREPTBlockSize;
 		nCurrentREPTBlockCount = pLastFile->nREPTBlockCount;
 		break;
+	default:
+		fatalerror("%s: Internal error.", __func__);
 	}
 
 	free(*ppLastFile);
@@ -174,12 +178,13 @@ int32_t fstk_GetLine(void)
 		return nLineNo; /* ??? */
 	case STAT_isREPTBlock:
 		break; /* Peek top file of the stack */
+	default:
+		fatalerror("%s: Internal error.", __func__);
 	}
 
 	pLastFile = pFileStack;
 
 	if (pLastFile != NULL) {
-		ppLastFile = &pFileStack;
 		while (pLastFile->pNext) {
 			ppLastFile = &(pLastFile->pNext);
 			pLastFile = *ppLastFile;
@@ -229,7 +234,7 @@ void fstk_AddIncludePath(char *s)
 		fatalerror("Include path too long '%s'", s);
 }
 
-FILE *fstk_FindFile(char *fname)
+FILE *fstk_FindFile(char *fname, char **incPathUsed)
 {
 	char path[_MAX_PATH];
 	int32_t i;
@@ -257,8 +262,10 @@ FILE *fstk_FindFile(char *fname)
 		 * space had been available. Thus, a return value of `size` or
 		 * more means that the output was truncated.
 		 */
-		if (snprintf(path, sizeof(path), "%s%s", IncludePaths[i], fname)
-		    >= sizeof(path))
+		int fullpathlen = snprintf(path, sizeof(path), "%s%s",
+					   IncludePaths[i], fname);
+
+		if (fullpathlen >= (int)sizeof(path))
 			continue;
 
 		f = fopen(path, "rb");
@@ -268,6 +275,8 @@ FILE *fstk_FindFile(char *fname)
 				fprintf(dependfile, "%s: %s\n", tzObjectname,
 					path);
 			}
+			if (incPathUsed)
+				*incPathUsed = IncludePaths[i];
 			return f;
 		}
 	}
@@ -281,7 +290,8 @@ FILE *fstk_FindFile(char *fname)
  */
 void fstk_RunInclude(char *tzFileName)
 {
-	FILE *f = fstk_FindFile(tzFileName);
+	char *incPathUsed = "";
+	FILE *f = fstk_FindFile(tzFileName, &incPathUsed);
 
 	if (f == NULL)
 		err(1, "Unable to open included file '%s'", tzFileName);
@@ -289,7 +299,8 @@ void fstk_RunInclude(char *tzFileName)
 	pushcontext();
 	nLineNo = 1;
 	nCurrentStatus = STAT_isInclude;
-	strcpy(tzCurrentFileName, tzFileName);
+	snprintf(tzCurrentFileName, sizeof(tzCurrentFileName), "%s%s",
+		 incPathUsed, tzFileName);
 	pCurrentFile = f;
 	CurrentFlexHandle = yy_create_buffer(pCurrentFile);
 	yy_switch_to_buffer(CurrentFlexHandle);
@@ -347,7 +358,7 @@ void fstk_RunMacroArg(int32_t s)
 
 	pushcontext();
 	nCurrentStatus = STAT_isMacroArg;
-	sprintf(tzCurrentFileName, "%c", (uint8_t)s);
+	snprintf(tzCurrentFileName, _MAX_PATH + 1, "%c", (uint8_t)s);
 	CurrentFlexHandle = yy_scan_bytes(sym, strlen(sym));
 	yy_switch_to_buffer(CurrentFlexHandle);
 }
@@ -410,7 +421,7 @@ void fstk_Init(char *s)
 
 	nMacroCount = 0;
 	nCurrentStatus = STAT_isInclude;
-	strcpy(tzCurrentFileName, tzFileName);
+	snprintf(tzCurrentFileName, _MAX_PATH + 1, "%s", tzFileName);
 	CurrentFlexHandle = yy_create_buffer(pCurrentFile);
 	yy_switch_to_buffer(CurrentFlexHandle);
 	nLineNo = 1;

src/asm/globlex.c

@@ -14,12 +14,15 @@
 #include <string.h>
 
 #include "asm/asm.h"
+#include "asm/constexpr.h"
 #include "asm/lexer.h"
 #include "asm/main.h"
 #include "asm/rpn.h"
 #include "asm/symbol.h"
 #include "asm/symbol.h"
 
+#include "helpers.h"
+
 #include "asmy.h"
 
 bool oDontExpandStrings;
@@ -93,9 +96,18 @@ static int32_t ascii2bin(char *s)
 		s += 1;
 		convertfunc = binary2bin;
 		break;
+	default:
+		/* Handle below */
+		break;
 	}
 
-	if (radix == 4) {
+	if (*s == '\0') {
+		/*
+		 * There are no digits after the radix prefix
+		 * (or the string is empty, which shouldn't happen).
+		 */
+		yyerror("Invalid integer constant");
+	} else if (radix == 4) {
 		int32_t c;
 
 		while (*s != '\0') {
@@ -216,7 +228,7 @@ uint32_t PutMacroArg(char *src, uint32_t size)
 	return 0;
 }
 
-uint32_t PutUniqueArg(char *src, uint32_t size)
+uint32_t PutUniqueArg(unused_ char *src, uint32_t size)
 {
 	char *s;
 
@@ -307,6 +319,7 @@ const struct sLexInitString lexer_strings[] = {
 	{"sp", T_MODE_SP},
 	{"[c]", T_MODE_C_IND},
 	{"[$ff00+c]", T_MODE_C_IND},
+	{"[$ff00 + c]", T_MODE_C_IND},
 
 	{"a", T_TOKEN_A},
 	{"b", T_TOKEN_B},
@@ -368,6 +381,7 @@ const struct sLexInitString lexer_strings[] = {
 
 	{"include", T_POP_INCLUDE},
 	{"printt", T_POP_PRINTT},
+	{"printi", T_POP_PRINTI},
 	{"printv", T_POP_PRINTV},
 	{"printf", T_POP_PRINTF},
 	{"export", T_POP_EXPORT},
@@ -578,7 +592,7 @@ void setup_lexer(void)
 	lex_FloatAddRange(id, '@', '@');
 	lex_FloatAddRange(id, '#', '#');
 
-	//@ID
+	// "@"
 
 	id = lex_FloatAlloc(&tIDToken);
 	lex_FloatAddFirstRange(id, '@', '@');

src/asm/lexer.c

@@ -6,6 +6,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -14,6 +15,7 @@
 #include <ctype.h>
 
 #include "asm/asm.h"
+#include "asm/constexpr.h"
 #include "asm/fstack.h"
 #include "asm/lexer.h"
 #include "asm/main.h"
@@ -110,6 +112,21 @@ void yy_delete_buffer(YY_BUFFER_STATE buf)
 	free(buf);
 }
 
+/*
+ * Maintains the following invariants:
+ * 1. nBufferSize < capacity
+ * 2. The buffer is terminated with 0
+ * 3. nBufferSize is the size without the terminator
+ */
+static void yy_buffer_append(YY_BUFFER_STATE buf, uint32_t capacity, char c)
+{
+	assert(buf->pBuffer[buf->nBufferSize] == 0);
+	assert(buf->nBufferSize + 1 < capacity);
+
+	buf->pBuffer[buf->nBufferSize++] = c;
+	buf->pBuffer[buf->nBufferSize] = 0;
+}
+
 YY_BUFFER_STATE yy_scan_bytes(char *mem, uint32_t size)
 {
 	YY_BUFFER_STATE pBuffer = malloc(sizeof(struct yy_buffer_state));
@@ -145,7 +162,10 @@ YY_BUFFER_STATE yy_create_buffer(FILE *f)
 	size = ftell(f);
 	fseek(f, 0, SEEK_SET);
 
-	pBuffer->pBufferRealStart = malloc(size + 2 + SAFETYMARGIN);
+	/* Give extra room for 2 newlines and terminator */
+	uint32_t capacity = size + 3;
+
+	pBuffer->pBufferRealStart = malloc(capacity + SAFETYMARGIN);
 
 	if (pBuffer->pBufferRealStart == NULL)
 		fatalerror("%s: Out of memory for buffer!", __func__);
@@ -155,9 +175,10 @@ YY_BUFFER_STATE yy_create_buffer(FILE *f)
 
 	size = fread(pBuffer->pBuffer, sizeof(uint8_t), size, f);
 
-	pBuffer->pBuffer[size] = '\n';
-	pBuffer->pBuffer[size + 1] = 0;
-	pBuffer->nBufferSize = size + 1;
+	pBuffer->pBuffer[size] = 0;
+	pBuffer->nBufferSize = size;
+
+	/* Convert all line endings to LF and spaces */
 
 	char *mem = pBuffer->pBuffer;
 	uint32_t instring = 0;
@@ -171,20 +192,44 @@ YY_BUFFER_STATE yy_create_buffer(FILE *f)
 		} else if (instring) {
 			mem += 1;
 		} else {
-			if ((mem[0] == 10 && mem[1] == 13)
-				|| (mem[0] == 13 && mem[1] == 10)) {
+			/* LF CR and CR LF */
+			if (((mem[0] == 10) && (mem[1] == 13))
+			 || ((mem[0] == 13) && (mem[1] == 10))) {
 				mem[0] = ' ';
 				mem[1] = '\n';
 				mem += 2;
-			} else if (mem[0] == 10 || mem[0] == 13) {
+			/* LF and CR */
+			} else if ((mem[0] == 10) || (mem[0] == 13)) {
 				mem[0] = '\n';
 				mem += 1;
-			} else if (mem[0] == '\n' && mem[1] == '*') {
+			} else {
 				mem += 1;
-				while (!(*mem == '\n' || *mem == '\0'))
+			}
+		}
+	}
+
+	/* Remove comments */
+
+	mem = pBuffer->pBuffer;
+	instring = 0;
+
+	while (*mem) {
+		if (*mem == '\"')
+			instring = 1 - instring;
+
+		if ((mem[0] == '\\') && (mem[1] == '\"' || mem[1] == '\\')) {
+			mem += 2;
+		} else if (instring) {
+			mem += 1;
+		} else {
+			/* Comments that start with ; anywhere in a line */
+			if (*mem == ';') {
+				while (!((*mem == '\n') || (*mem == '\0')))
 					*mem++ = ' ';
-			} else if (*mem == ';') {
-				while (!(*mem == '\n' || *mem == '\0'))
+			/* Comments that start with * at the start of a line */
+			} else if ((mem[0] == '\n') && (mem[1] == '*')) {
+				mem += 1;
+				while (!((*mem == '\n') || (*mem == '\0')))
 					*mem++ = ' ';
 			} else {
 				mem += 1;
@@ -192,6 +237,22 @@ YY_BUFFER_STATE yy_create_buffer(FILE *f)
 		}
 	}
 
+	/* Add newline if file doesn't end with one */
+	if (size == 0 || pBuffer->pBuffer[size - 1] != '\n')
+		yy_buffer_append(pBuffer, capacity, '\n');
+
+	/* Add newline if \ will eat the last newline */
+	if (pBuffer->nBufferSize >= 2) {
+		size_t pos = pBuffer->nBufferSize - 2;
+
+		/* Skip spaces */
+		while (pos > 0 && pBuffer->pBuffer[pos] == ' ')
+			pos--;
+
+		if (pBuffer->pBuffer[pos] == '\\')
+			yy_buffer_append(pBuffer, capacity, '\n');
+	}
+
 	pBuffer->oAtLineStart = 1;
 	return pBuffer;
 }
@@ -388,7 +449,7 @@ void yylex_GetFloatMaskAndFloatLen(uint32_t *pnFloatMask, uint32_t *pnFloatLen)
 /*
  * Gets the longest keyword/operator from the current position in the buffer.
  */
-struct sLexString *yylex_GetLongestFixed()
+struct sLexString *yylex_GetLongestFixed(void)
 {
 	struct sLexString *pLongestFixed = NULL;
 	char *s = pLexBuffer;
@@ -612,6 +673,43 @@ scanagain:
 		}
 	}
 
+	/* Check for line continuation character */
+	if (*pLexBuffer == '\\') {
+		/*
+		 * Look for line continuation character after a series of
+		 * spaces. This is also useful for files that use Windows line
+		 * endings: "\r\n" is replaced by " \n" before the lexer has the
+		 * opportunity to see it.
+		 */
+		if (pLexBuffer[1] == ' ') {
+			pLexBuffer += 2;
+			while (1) {
+				if (*pLexBuffer == ' ') {
+					pLexBuffer++;
+				} else if (*pLexBuffer == '\n') {
+					pLexBuffer++;
+					nLineNo += 1;
+					goto scanagain;
+				} else {
+					errx(1, "Expected a new line after the continuation character.");
+				}
+			}
+		}
+
+		/* Line continuation character */
+		if (pLexBuffer[1] == '\n') {
+			pLexBuffer += 2;
+			nLineNo += 1;
+			goto scanagain;
+		}
+
+		/*
+		 * If there isn't a newline character or a space, ignore the
+		 * character '\'. It will eventually be handled by other
+		 * functions like PutMacroArg().
+		 */
+	}
+
 	/*
 	 * Try to match an identifier, macro argument (e.g. \1),
 	 * or numeric literal.
@@ -672,6 +770,7 @@ scanagain:
 
 	/* Longest match was a keyword or operator. */
 	pLexBuffer += pLongestFixed->nNameLength;
+	yylval.nConstValue = pLongestFixed->nToken;
 	return pLongestFixed->nToken;
 }
 
@@ -699,6 +798,9 @@ static uint32_t yylex_MACROARGS(void)
 			case '\\':
 				ch = '\\';
 				break;
+			case '"':
+				ch = '\"';
+				break;
 			case ',':
 				ch = ',';
 				break;
@@ -708,6 +810,32 @@ static uint32_t yylex_MACROARGS(void)
 			case '}':
 				ch = '}';
 				break;
+			case ' ':
+				/*
+				 * Look for line continuation character after a
+				 * series of spaces. This is also useful for
+				 * files that use Windows line endings: "\r\n"
+				 * is replaced by " \n" before the lexer has the
+				 * opportunity to see it.
+				 */
+				while (1) {
+					if (*pLexBuffer == ' ') {
+						pLexBuffer++;
+					} else if (*pLexBuffer == '\n') {
+						pLexBuffer++;
+						nLineNo += 1;
+						ch = 0;
+						break;
+					} else {
+						errx(1, "Expected a new line after the continuation character.");
+					}
+				}
+				break;
+			case '\n':
+				/* Line continuation character */
+				nLineNo += 1;
+				ch = 0;
+				break;
 			default:
 				maxLength = MAXSTRLEN - index;
 				length = CopyMacroArg(&yylval.tzString[index],
@@ -758,7 +886,7 @@ uint32_t yylex(void)
 		return yylex_NORMAL();
 	case LEX_STATE_MACROARGS:
 		return yylex_MACROARGS();
+	default:
+		fatalerror("%s: Internal error.", __func__);
 	}
-
-	fatalerror("Internal error in %s", __func__);
 }

src/asm/main.c

@@ -6,6 +6,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <float.h>
 #include <math.h>
 #include <stdarg.h>
 #include <stdio.h>
@@ -23,6 +24,7 @@
 
 #include "extern/err.h"
 
+#include "helpers.h"
 #include "version.h"
 
 extern int yyparse(void);
@@ -147,10 +149,13 @@ void opt_Parse(char *s)
 	case 'z':
 		if (strlen(&s[1]) <= 2) {
 			int32_t result;
+			unsigned int fillchar;
 
-			result = sscanf(&s[1], "%x", &newopt.fillchar);
+			result = sscanf(&s[1], "%x", &fillchar);
 			if (!((result == EOF) || (result == 1)))
 				errx(1, "Invalid argument for option 'z'");
+
+			newopt.fillchar = fillchar;
 		} else {
 			errx(1, "Invalid argument for option 'z'");
 		}
@@ -222,7 +227,7 @@ void opt_AddDefine(char *s)
 
 static void opt_ParseDefines(void)
 {
-	int32_t i;
+	uint32_t i;
 
 	for (i = 0; i < cldefines_index; i += 2)
 		sym_AddString(cldefines[i], cldefines[i + 1]);
@@ -235,7 +240,7 @@ void verror(const char *fmt, va_list args)
 {
 	fprintf(stderr, "ERROR: ");
 	fstk_Dump();
-	fprintf(stderr, ":\n\t");
+	fprintf(stderr, ":\n    ");
 	vfprintf(stderr, fmt, args);
 	fprintf(stderr, "\n");
 	nErrors += 1;
@@ -250,7 +255,7 @@ void yyerror(const char *fmt, ...)
 	va_end(args);
 }
 
-void fatalerror(const char *fmt, ...)
+noreturn_ void fatalerror(const char *fmt, ...)
 {
 	va_list args;
 
@@ -272,7 +277,7 @@ void warning(const char *fmt, ...)
 
 	fprintf(stderr, "warning: ");
 	fstk_Dump();
-	fprintf(stderr, ":\n\t");
+	fprintf(stderr, ":\n    ");
 	vfprintf(stderr, fmt, args);
 	fprintf(stderr, "\n");
 
@@ -282,7 +287,7 @@ void warning(const char *fmt, ...)
 static void print_usage(void)
 {
 	printf(
-"usage: rgbasm [-EhVvw] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"
+"usage: rgbasm [-EhLVvw] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"
 "              [-M dependfile] [-o outfile] [-p pad_value] file.asm\n");
 	exit(1);
 }
@@ -316,17 +321,18 @@ int main(int argc, char *argv[])
 	DefaultOptions.gbgfx[3] = '3';
 	DefaultOptions.binary[0] = '0';
 	DefaultOptions.binary[1] = '1';
-	DefaultOptions.fillchar = 0;
-	DefaultOptions.verbose = false;
-	DefaultOptions.haltnop = true;
 	DefaultOptions.exportall = false;
+	DefaultOptions.fillchar = 0;
+	DefaultOptions.optimizeloads = true;
+	DefaultOptions.haltnop = true;
+	DefaultOptions.verbose = false;
 	DefaultOptions.warnings = true;
 
 	opt_SetCurrentOptions(&DefaultOptions);
 
 	newopt = CurrentOptions;
 
-	while ((ch = getopt(argc, argv, "b:D:g:hi:M:o:p:EVvw")) != -1) {
+	while ((ch = getopt(argc, argv, "b:D:Eg:hi:LM:o:p:Vvw")) != -1) {
 		switch (ch) {
 		case 'b':
 			if (strlen(optarg) == 2) {
@@ -358,6 +364,9 @@ int main(int argc, char *argv[])
 		case 'i':
 			fstk_AddIncludePath(optarg);
 			break;
+		case 'L':
+			newopt.optimizeloads = false;
+			break;
 		case 'M':
 			dependfile = fopen(optarg, "w");
 			if (dependfile == NULL)
@@ -476,7 +485,7 @@ int main(int argc, char *argv[])
 	if (CurrentOptions.verbose) {
 		printf("Success! %u lines in %d.%02d seconds ", nTotalLines,
 		       (int)timespent, ((int)(timespent * 100.0)) % 100);
-		if (timespent == 0)
+		if (timespent < FLT_MIN_EXP)
 			printf("(INFINITY lines/minute)\n");
 		else
 			printf("(%d lines/minute)\n",

src/asm/output.c

@@ -593,7 +593,7 @@ void out_SetFileName(char *s)
 }
 
 /*
- * Find a section by name and type.  If it doesn't exist, create it
+ * Find a section by name and type. If it doesn't exist, create it
  */
 struct Section *out_FindSection(char *pzName, uint32_t secttype, int32_t org,
 				int32_t bank, int32_t alignment)
@@ -764,7 +764,7 @@ void out_String(char *s)
 }
 
 /*
- * Output a relocatable byte.  Checking will be done to see if it
+ * Output a relocatable byte. Checking will be done to see if it
  * is an absolute value in disguise.
  */
 void out_RelByte(struct Expression *expr)
@@ -803,7 +803,7 @@ void out_AbsWord(int32_t b)
 }
 
 /*
- * Output a relocatable word.  Checking will be done to see if
+ * Output a relocatable word. Checking will be done to see if
  * it's an absolute value in disguise.
  */
 void out_RelWord(struct Expression *expr)
@@ -847,7 +847,7 @@ void out_AbsLong(int32_t b)
 }
 
 /*
- * Output a relocatable longword.  Checking will be done to see if
+ * Output a relocatable longword. Checking will be done to see if
  * is an absolute value in disguise.
  */
 void out_RelLong(struct Expression *expr)
@@ -875,19 +875,23 @@ void out_RelLong(struct Expression *expr)
 }
 
 /*
- * Output a PC-relative byte
+ * Output a PC-relative relocatable byte. Checking will be done to see if it
+ * is an absolute value in disguise.
  */
 void out_PCRelByte(struct Expression *expr)
 {
-	int32_t b = expr->nVal;
-
 	checkcodesection();
 	checksectionoverflow(1);
-	b = (b & 0xFFFF) - (nPC + 1);
-	if (nPass == 2 && (b < -128 || b > 127))
-		yyerror("PC-relative value must be 8-bit");
 
-	out_AbsByte(b);
+	/* Always let the linker calculate the offset. */
+	if (nPass == 2) {
+		pCurrentSection->tData[nPC] = 0;
+		createpatch(PATCH_BYTE_JR, expr);
+	}
+	pCurrentSection->nPC += 1;
+	nPC += 1;
+	pPCSymbol->nValue += 1;
+
 	rpn_Reset(expr);
 }
 
@@ -898,7 +902,7 @@ void out_BinaryFile(char *s)
 {
 	FILE *f;
 
-	f = fstk_FindFile(s);
+	f = fstk_FindFile(s, NULL);
 	if (f == NULL)
 		err(1, "Unable to open incbin file '%s'", s);
 
@@ -934,7 +938,7 @@ void out_BinaryFileSlice(char *s, int32_t start_pos, int32_t length)
 	if (length < 0)
 		fatalerror("Number of bytes to read must be greater than zero");
 
-	f = fstk_FindFile(s);
+	f = fstk_FindFile(s, NULL);
 	if (f == NULL)
 		err(1, "Unable to open included file '%s'", s);
 

src/asm/rgbasm.1

@@ -5,7 +5,7 @@
 .\"
 .\" SPDX-License-Identifier: MIT
 .\"
-.Dd January 26, 2018
+.Dd February 24, 2018
 .Dt RGBASM 1
 .Os RGBDS Manual
 .Sh NAME
@@ -13,7 +13,7 @@
 .Nd Game Boy assembler
 .Sh SYNOPSIS
 .Nm rgbasm
-.Op Fl EhVvw
+.Op Fl EhLVvw
 .Op Fl b Ar chars
 .Op Fl D Ar name Ns Op = Ns Ar value
 .Op Fl g Ar chars
@@ -55,6 +55,12 @@ The
 option disables this behavior.
 .It Fl i Ar path
 Add an include path.
+.It Fl L
+Disable the optimization that turns loads of the form
+.Sy LD [$FF00+n8],A
+into the opcode
+.Sy LDH [$FF00+n8],A
+in order to have full control of the result in the final ROM.
 .It Fl M Ar dependfile
 Print
 .Xr make 1
@@ -75,7 +81,9 @@ Disable warning output.
 .Sh EXAMPLES
 Assembling a basic source file is simple:
 .Pp
-.D1 $ rgbasm -o bar.o foo.asm
+.Bd -literal -offset indent
+$ rgbasm -o bar.o foo.asm
+.Ed
 .Pp
 The resulting object file is not yet a usable ROM image \(em it must first be
 run through

src/asm/rpn.c

@@ -330,6 +330,15 @@ void rpn_SHL(struct Expression *expr, const struct Expression *src1,
 	     const struct Expression *src2)
 {
 	joinexpr();
+
+	if (src1->nVal < 0)
+		warning("Left shift of negative value: %d", src1->nVal);
+
+	if (src2->nVal < 0)
+		fatalerror("Shift by negative value: %d", src2->nVal);
+	else if (src2->nVal >= 32)
+		fatalerror("Shift by too big value: %d", src2->nVal);
+
 	expr->nVal = (expr->nVal << src2->nVal);
 	pushbyte(expr, RPN_SHL);
 }
@@ -338,6 +347,11 @@ void rpn_SHR(struct Expression *expr, const struct Expression *src1,
 	     const struct Expression *src2)
 {
 	joinexpr();
+	if (src2->nVal < 0)
+		fatalerror("Shift by negative value: %d", src2->nVal);
+	else if (src2->nVal >= 32)
+		fatalerror("Shift by too big value: %d", src2->nVal);
+
 	expr->nVal = (expr->nVal >> src2->nVal);
 	pushbyte(expr, RPN_SHR);
 }
@@ -355,7 +369,7 @@ void rpn_DIV(struct Expression *expr, const struct Expression *src1,
 {
 	joinexpr();
 	if (src2->nVal == 0)
-		fatalerror("division by zero");
+		fatalerror("Division by zero");
 
 	expr->nVal = (expr->nVal / src2->nVal);
 	pushbyte(expr, RPN_DIV);
@@ -366,7 +380,7 @@ void rpn_MOD(struct Expression *expr, const struct Expression *src1,
 {
 	joinexpr();
 	if (src2->nVal == 0)
-		fatalerror("division by zero");
+		fatalerror("Division by zero");
 
 	expr->nVal = (expr->nVal % src2->nVal);
 	pushbyte(expr, RPN_MOD);

src/asm/symbol.c

@@ -25,6 +25,7 @@
 
 #include "extern/err.h"
 
+#include "helpers.h"
 #include "version.h"
 
 struct sSymbol *tHashedSymbols[HASHSIZE];
@@ -40,7 +41,7 @@ static char SavedTIMESTAMP_ISO8601_LOCAL[256];
 static char SavedTIMESTAMP_ISO8601_UTC[256];
 static char SavedDAY[3];
 static char SavedMONTH[3];
-static char SavedYEAR[5];
+static char SavedYEAR[20];
 static char SavedHOUR[3];
 static char SavedMINUTE[3];
 static char SavedSECOND[3];
@@ -62,7 +63,7 @@ void helper_RemoveLeadingZeros(char *string)
 	memmove(string, new_beginning, strlen(new_beginning) + 1);
 }
 
-int32_t Callback_NARG(struct sSymbol *sym)
+int32_t Callback_NARG(unused_ struct sSymbol *sym)
 {
 	uint32_t i = 0;
 
@@ -72,7 +73,7 @@ int32_t Callback_NARG(struct sSymbol *sym)
 	return i;
 }
 
-int32_t Callback__LINE__(struct sSymbol __attribute__((unused)) *sym)
+int32_t Callback__LINE__(unused_ struct sSymbol *sym)
 {
 	return nLineNo;
 }
@@ -101,6 +102,19 @@ uint32_t calchash(char *s)
 	return hash % HASHSIZE;
 }
 
+/*
+ * Update a symbol's definition filename and line
+ */
+void updateSymbolFilename(struct sSymbol *nsym)
+{
+	if (snprintf(nsym->tzFileName, _MAX_PATH + 1, "%s",
+		     tzCurrentFileName) > _MAX_PATH) {
+		fatalerror("%s: File name is too long: '%s'", __func__,
+			   tzCurrentFileName);
+	}
+	nsym->nFileLine = fstk_GetLine();
+}
+
 /*
  * Create a new symbol by name
  */
@@ -122,7 +136,9 @@ struct sSymbol *createsymbol(char *s)
 		return NULL;
 	}
 
-	strcpy((*ppsym)->tzName, s);
+	if (snprintf((*ppsym)->tzName, MAXSYMLEN + 1, "%s", s) > MAXSYMLEN)
+		warning("Symbol name is too long: '%s'", s);
+
 	(*ppsym)->nValue = 0;
 	(*ppsym)->nType = 0;
 	(*ppsym)->pScope = NULL;
@@ -130,8 +146,7 @@ struct sSymbol *createsymbol(char *s)
 	(*ppsym)->pMacro = NULL;
 	(*ppsym)->pSection = NULL;
 	(*ppsym)->Callback = NULL;
-	strcpy((*ppsym)->tzFileName, tzCurrentFileName);
-	(*ppsym)->nFileLine = fstk_GetLine();
+	updateSymbolFilename(*ppsym);
 	return *ppsym;
 }
 
@@ -509,7 +524,7 @@ void sym_SetMacroArgID(uint32_t nMacroCount)
 {
 	char s[256];
 
-	sprintf(s, "_%u", nMacroCount);
+	snprintf(s, sizeof(s), "_%u", nMacroCount);
 	newmacroargs[MAXMACROARGS] = strdup(s);
 }
 
@@ -551,6 +566,7 @@ void sym_AddEqu(char *tzSym, int32_t value)
 			nsym->nValue = value;
 			nsym->nType |= SYMF_EQU | SYMF_DEFINED | SYMF_CONST;
 			nsym->pScope = NULL;
+			updateSymbolFilename(nsym);
 		}
 	}
 }
@@ -560,7 +576,7 @@ void sym_AddEqu(char *tzSym, int32_t value)
  *
  * If the desired symbol is a string it needs to be passed to this function with
  * quotes inside the string, like sym_AddString("name", "\"test\"), or the
- * assembler won't be able to use it with DB and similar. This is equivalent as
+ * assembler won't be able to use it with DB and similar. This is equivalent to
  * ``` name EQUS "\"test\"" ```
  *
  * If the desired symbol is a register or a number, just the terminator quotes
@@ -624,6 +640,7 @@ void sym_AddSet(char *tzSym, int32_t value)
 		nsym->nValue = value;
 		nsym->nType |= SYMF_SET | SYMF_DEFINED | SYMF_CONST;
 		nsym->pScope = NULL;
+		updateSymbolFilename(nsym);
 	}
 }
 
@@ -665,7 +682,7 @@ void sym_AddReloc(char *tzSym)
 
 			struct sSymbol *parent = pScope->pScope ?
 						 pScope->pScope : pScope;
-			int32_t parentLen = localPtr - tzSym;
+			uint32_t parentLen = localPtr - tzSym;
 
 			if (strchr(localPtr + 1, '.') != NULL) {
 				fatalerror("'%s' is a nonsensical reference to a nested local symbol",
@@ -701,6 +718,8 @@ void sym_AddReloc(char *tzSym)
 
 			nsym->pScope = scope;
 			nsym->pSection = pCurrentSection;
+
+			updateSymbolFilename(nsym);
 		}
 	}
 	pScope = findsymbol(tzSym, scope);
@@ -831,6 +850,7 @@ void sym_AddMacro(char *tzSym)
 			nsym->pScope = NULL;
 			nsym->ulMacroSize = ulNewMacroSize;
 			nsym->pMacro = tzNewMacro;
+			updateSymbolFilename(nsym);
 		}
 	}
 }
@@ -965,16 +985,22 @@ void sym_Init(void)
 		 * The '?' have to be escaped or they will be treated as
 		 * trigraphs...
 		 */
-		strcpy(SavedTIME, "\"\?\?:\?\?:\?\?\"");
-		strcpy(SavedDATE, "\"\?\? \?\?\? \?\?\?\?\"");
-		strcpy(SavedTIMESTAMP_ISO8601_LOCAL, "\"\?\?\?\?-\?\?-\?\?T\?\?:\?\?:\?\?+\?\?\?\?\"");
-		strcpy(SavedTIMESTAMP_ISO8601_UTC, "\"\?\?\?\?-\?\?-\?\?T\?\?:\?\?:\?\?Z\"");
-		strcpy(SavedDAY, "1");
-		strcpy(SavedMONTH, "1");
-		strcpy(SavedYEAR, "1900");
-		strcpy(SavedHOUR, "0");
-		strcpy(SavedMINUTE, "0");
-		strcpy(SavedSECOND, "0");
+		snprintf(SavedTIME, sizeof(SavedTIME),
+			 "\"\?\?:\?\?:\?\?\"");
+		snprintf(SavedDATE, sizeof(SavedDATE),
+			 "\"\?\? \?\?\? \?\?\?\?\"");
+		snprintf(SavedTIMESTAMP_ISO8601_LOCAL,
+			 sizeof(SavedTIMESTAMP_ISO8601_LOCAL),
+			 "\"\?\?\?\?-\?\?-\?\?T\?\?:\?\?:\?\?+\?\?\?\?\"");
+		snprintf(SavedTIMESTAMP_ISO8601_UTC,
+			 sizeof(SavedTIMESTAMP_ISO8601_UTC),
+			 "\"\?\?\?\?-\?\?-\?\?T\?\?:\?\?:\?\?Z\"");
+		snprintf(SavedDAY, sizeof(SavedDAY), "1");
+		snprintf(SavedMONTH, sizeof(SavedMONTH), "1");
+		snprintf(SavedYEAR, sizeof(SavedYEAR), "1900");
+		snprintf(SavedHOUR, sizeof(SavedHOUR), "0");
+		snprintf(SavedMINUTE, sizeof(SavedMINUTE), "0");
+		snprintf(SavedSECOND, sizeof(SavedSECOND), "0");
 	}
 
 	sym_AddString("__TIME__", SavedTIME);

src/extern/err.c

@@ -33,7 +33,7 @@ void rgbds_vwarnx(const char *fmt, va_list ap)
 	putc('\n', stderr);
 }
 
-noreturn void rgbds_verr(int status, const char *fmt, va_list ap)
+noreturn_ void rgbds_verr(int status, const char *fmt, va_list ap)
 {
 	fprintf(stderr, "error");
 	if (fmt) {
@@ -44,7 +44,7 @@ noreturn void rgbds_verr(int status, const char *fmt, va_list ap)
 	exit(status);
 }
 
-noreturn void rgbds_verrx(int status, const char *fmt, va_list ap)
+noreturn_ void rgbds_verrx(int status, const char *fmt, va_list ap)
 {
 	fprintf(stderr, "error");
 	if (fmt) {
@@ -73,7 +73,7 @@ void rgbds_warnx(const char *fmt, ...)
 	va_end(ap);
 }
 
-noreturn void rgbds_err(int status, const char *fmt, ...)
+noreturn_ void rgbds_err(int status, const char *fmt, ...)
 {
 	va_list ap;
 
@@ -82,7 +82,7 @@ noreturn void rgbds_err(int status, const char *fmt, ...)
 	va_end(ap);
 }
 
-noreturn void rgbds_errx(int status, const char *fmt, ...)
+noreturn_ void rgbds_errx(int status, const char *fmt, ...)
 {
 	va_list ap;
 

src/extern/utf8decoder.c

@@ -11,34 +11,31 @@
 #include <stdint.h>
 
 static const uint8_t utf8d[] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 00..0f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 10..1f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 20..2f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 30..3f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 40..4f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 50..5f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 60..6f */
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 70..7f */
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 80..8f */
-	9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, /* 90..9f */
-	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, /* a0..af */
-	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, /* b0..bf */
-	8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* c0..cf */
-	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* d0..df */
-	0xa, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, /* e0..e7 */
-	0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, /* e8..ef */
-	0xb, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, /* f0..f7 */
-	0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, /* f8..ff */
-	0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, /* s0..   */
-	0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, /*   ..s0 */
-	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* s1 */
-	1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, /* s1 */
-	1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, /* s3 */
-	1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, /* s4 */
-	1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, /* s5 */
-	1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, /* s6 */
-	1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, /* s7 */
-	1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* s8 */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 00..0f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 10..1f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 20..2f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 30..3f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 40..4f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 50..5f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 60..6f */
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 70..7f */
+	  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 80..8f */
+	  9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, /* 90..9f */
+	  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, /* a0..af */
+	  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, /* b0..bf */
+	  8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* c0..cf */
+	  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* d0..df */
+	 10, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, /* e0..ef */
+	 11, 6, 6, 6, 5, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, /* f0..ff */
+	  0, 1, 2, 3, 5, 8, 7, 1, 1, 1, 4, 6, 1, 1, 1, 1, /* s0 */
+	  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* s1 */
+	  1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, /* s1 */
+	  1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, /* s3 */
+	  1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, /* s4 */
+	  1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, /* s5 */
+	  1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, /* s6 */
+	  1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, /* s7 */
+	  1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* s8 */
 };
 
 uint32_t decode(uint32_t *state, uint32_t *codep, uint32_t byte)

src/fix/main.c

@@ -20,9 +20,9 @@
 static void print_usage(void)
 {
 	printf(
-"usage: rgbfix [-CcjsVv] [-i game_id] [-k licensee_str] [-l licensee_id]\n"
-"              [-m mbc_type] [-n rom_version] [-p pad_value] [-r ram_size]\n"
-"              [-t title_str] file\n");
+"usage: rgbfix [-CcjsVv] [-f fix_spec] [-i game_id] [-k licensee_str]\n"
+"              [-l licensee_id] [-m mbc_type] [-n rom_version] [-p pad_value]\n"
+"              [-r ram_size] [-t title_str] file\n");
 	exit(1);
 }
 
@@ -37,7 +37,12 @@ int main(int argc, char *argv[])
 	 */
 
 	/* all flags default to false unless options specify otherwise */
-	bool validate = false;
+	bool fixlogo = false;
+	bool fixheadsum = false;
+	bool fixglobalsum = false;
+	bool trashlogo = false;
+	bool trashheadsum = false;
+	bool trashglobalsum = false;
 	bool settitle = false;
 	bool setid = false;
 	bool colorcompatible = false;
@@ -61,7 +66,7 @@ int main(int argc, char *argv[])
 	int version = 0;   /* mask ROM version number */
 	int padvalue = 0;  /* to pad the rom with if it changes size */
 
-	while ((ch = getopt(argc, argv, "Cci:jk:l:m:n:p:sr:t:Vv")) != -1) {
+	while ((ch = getopt(argc, argv, "Ccf:i:jk:l:m:n:p:sr:t:Vv")) != -1) {
 		switch (ch) {
 		case 'C':
 			coloronly = true;
@@ -69,6 +74,14 @@ int main(int argc, char *argv[])
 		case 'c':
 			colorcompatible = true;
 			break;
+		case 'f':
+			fixlogo = strchr(optarg, 'l');
+			fixheadsum = strchr(optarg, 'h');
+			fixglobalsum = strchr(optarg, 'g');
+			trashlogo = strchr(optarg, 'L');
+			trashheadsum = strchr(optarg, 'H');
+			trashglobalsum = strchr(optarg, 'G');
+			break;
 		case 'i':
 			setid = true;
 
@@ -168,7 +181,9 @@ int main(int argc, char *argv[])
 			printf("rgbfix %s\n", get_package_version_string());
 			exit(0);
 		case 'v':
-			validate = true;
+			fixlogo = true;
+			fixheadsum = true;
+			fixglobalsum = true;
 			break;
 		default:
 			print_usage();
@@ -192,10 +207,20 @@ int main(int argc, char *argv[])
 		err(1, "Error opening file %s", argv[argc - 1]);
 
 	/*
-	 * Write changes to ROM
+	 * Read ROM header
+	 *
+	 * Offsets in the buffer are 0x100 less than the equivalent in ROM.
 	 */
 
-	if (validate) {
+	uint8_t header[0x50];
+
+	if (fseek(rom, 0x100, SEEK_SET) != 0)
+		err(1, "Could not locate ROM header");
+	if (fread(header, sizeof(uint8_t), sizeof(header), rom)
+	    != sizeof(header))
+		err(1, "Could not read ROM header");
+
+	if (fixlogo || trashlogo) {
 		/*
 		 * Offset 0x104–0x133: Nintendo Logo
 		 * This is a bitmap image that displays when the Game Boy is
@@ -205,7 +230,7 @@ int main(int argc, char *argv[])
 		/*
 		 * See also: global checksums at 0x14D–0x14F, They must
 		 * also be correct for the game to boot, so we fix them
-		 * as well when the -v flag is set.
+		 * as well when requested with the -f flag.
 		 */
 
 		uint8_t ninlogo[48] = {
@@ -217,8 +242,12 @@ int main(int argc, char *argv[])
 			0xDD, 0xDC, 0x99, 0x9F, 0xBB, 0xB9, 0x33, 0x3E
 		};
 
-		fseek(rom, 0x104, SEEK_SET);
-		fwrite(ninlogo, 1, 48, rom);
+		if (trashlogo) {
+			for (int i = 0; i < sizeof(ninlogo); i++)
+				ninlogo[i] = ~ninlogo[i];
+		}
+
+		memcpy(header + 0x04, ninlogo, sizeof(ninlogo));
 	}
 
 	if (settitle) {
@@ -239,11 +268,10 @@ int main(int argc, char *argv[])
 		 * characters may conflict with the title.
 		 */
 
-		fseek(rom, 0x134, SEEK_SET);
-		fwrite(title, 1, strlen(title) + 1, rom);
+		int n = snprintf((char *)header + 0x34, 16, "%s", title);
 
-		while (ftell(rom) < 0x143)
-			fputc(0, rom);
+		for (int i = 16; i > n; i--)
+			header[0x34 + i] = '\0';
 	}
 
 	if (setid) {
@@ -253,8 +281,7 @@ int main(int argc, char *argv[])
 		 * characters).
 		 */
 
-		fseek(rom, 0x13F, SEEK_SET);
-		fwrite(id, 1, 4, rom);
+		memcpy(header + 0x3F, id, 4);
 	}
 
 	if (colorcompatible) {
@@ -272,20 +299,12 @@ int main(int argc, char *argv[])
 		 * may conflict.
 		 */
 
-		uint8_t byte;
-
-		fseek(rom, 0x143, SEEK_SET);
-		byte = fgetc(rom);
-
-		byte |= 1 << 7;
+		header[0x43] |= 1 << 7;
 		if (coloronly)
-			byte |= 1 << 6;
+			header[0x43] |= 1 << 6;
 
-		if (byte & 0x3F)
+		if (header[0x43] & 0x3F)
 			warnx("Color flag conflicts with game title");
-
-		fseek(rom, 0x143, SEEK_SET);
-		fputc(byte, rom);
 	}
 
 	if (setnewlicensee) {
@@ -301,8 +320,8 @@ int main(int argc, char *argv[])
 		 * as a Super Game Boy flag.
 		 */
 
-		fseek(rom, 0x144, SEEK_SET);
-		fwrite(newlicensee, 1, 2, rom);
+		header[0x44] = newlicensee[0];
+		header[0x45] = newlicensee[1];
 	}
 
 	if (super) {
@@ -321,8 +340,7 @@ int main(int argc, char *argv[])
 		if (!setlicensee)
 			warnx("You should probably set both '-s' and '-l 0x33'");
 
-		fseek(rom, 0x146, SEEK_SET);
-		fputc(3, rom);
+		header[0x46] = 3;
 	}
 
 	if (setcartridge) {
@@ -332,8 +350,7 @@ int main(int argc, char *argv[])
 		 * external RAM, timer, rumble, or battery.
 		 */
 
-		fseek(rom, 0x147, SEEK_SET);
-		fputc(cartridge, rom);
+		header[0x47] = cartridge;
 	}
 
 	if (resize) {
@@ -347,8 +364,13 @@ int main(int argc, char *argv[])
 		int headbyte;
 		uint8_t *buf;
 
-		fseek(rom, 0, SEEK_END);
+		if (fseek(rom, 0, SEEK_END) != 0)
+			err(1, "Could not pad ROM file");
+
 		romsize = ftell(rom);
+		if (romsize == -1)
+			err(1, "Could not pad ROM file");
+
 		newsize = 0x8000;
 
 		headbyte = 0;
@@ -361,11 +383,14 @@ int main(int argc, char *argv[])
 			warnx("ROM size is bigger than 8MiB");
 
 		buf = malloc(newsize - romsize);
-		memset(buf, padvalue, newsize - romsize);
-		fwrite(buf, 1, newsize - romsize, rom);
+		if (buf == NULL)
+			errx(1, "Couldn't allocate memory for padded ROM.");
 
-		fseek(rom, 0x148, SEEK_SET);
-		fputc(headbyte, rom);
+		memset(buf, padvalue, newsize - romsize);
+		if (fwrite(buf, 1, newsize - romsize, rom) != newsize - romsize)
+			err(1, "Could not pad ROM file");
+
+		header[0x48] = headbyte;
 
 		free(buf);
 	}
@@ -375,8 +400,7 @@ int main(int argc, char *argv[])
 		 * Offset 0x149: RAM Size
 		 */
 
-		fseek(rom, 0x149, SEEK_SET);
-		fputc(ramsize, rom);
+		header[0x49] = ramsize;
 	}
 
 	if (nonjapan) {
@@ -384,8 +408,7 @@ int main(int argc, char *argv[])
 		 * Offset 0x14A: Non-Japanese Region Flag
 		 */
 
-		fseek(rom, 0x14A, SEEK_SET);
-		fputc(1, rom);
+		header[0x4A] = 1;
 	}
 
 	if (setlicensee) {
@@ -401,8 +424,7 @@ int main(int argc, char *argv[])
 		 * See also: the New Licensee ID at 0x144–0x145.
 		 */
 
-		fseek(rom, 0x14B, SEEK_SET);
-		fputc(licensee, rom);
+		header[0x4B] = licensee;
 	}
 
 	if (setversion) {
@@ -411,46 +433,71 @@ int main(int argc, char *argv[])
 		 * Which version of the ROM this is.
 		 */
 
-		fseek(rom, 0x14C, SEEK_SET);
-		fputc(version, rom);
+		header[0x4C] = version;
 	}
 
-	if (validate) {
+	if (fixheadsum || trashheadsum) {
 		/*
 		 * Offset 0x14D: Header Checksum
 		 */
 
 		uint8_t headcksum = 0;
 
-		fseek(rom, 0x134, SEEK_SET);
-		for (int i = 0; i < (0x14D - 0x134); ++i)
-			headcksum = headcksum - fgetc(rom) - 1;
+		for (int i = 0x34; i < 0x4D; ++i)
+			headcksum = headcksum - header[i] - 1;
 
-		fseek(rom, 0x14D, SEEK_SET);
-		fputc(headcksum, rom);
+		if (trashheadsum)
+			headcksum = ~headcksum;
 
+		header[0x4D] = headcksum;
+	}
+
+	/*
+	 * Before calculating the global checksum, we must write the modified
+	 * header to the ROM.
+	 */
+
+	if (fseek(rom, 0x100, SEEK_SET) != 0)
+		err(1, "Could not locate header for writing");
+
+	if (fwrite(header, sizeof(uint8_t), sizeof(header), rom)
+	    != sizeof(header))
+		err(1, "Could not write modified ROM header");
+
+	if (fixglobalsum || trashglobalsum) {
 		/*
 		 * Offset 0x14E–0x14F: Global Checksum
 		 */
 
 		uint16_t globalcksum = 0;
 
-		rewind(rom);
-		for (int i = 0; i < 0x14E; ++i)
-			globalcksum += fgetc(rom);
+		if (fseek(rom, 0, SEEK_SET) != 0)
+			err(1, "Could not start calculating global checksum");
 
+		int i = 0;
 		int byte;
 
-		fseek(rom, 0x150, SEEK_SET);
-		while ((byte = fgetc(rom)) != EOF)
-			globalcksum += byte;
+		while ((byte = fgetc(rom)) != EOF) {
+			if (i != 0x14E && i != 0x14F)
+				globalcksum += byte;
+			i++;
+		}
+
+		if (ferror(rom))
+			err(1, "Could not calculate global checksum");
+
+		if (trashglobalsum)
+			globalcksum = ~globalcksum;
 
 		fseek(rom, 0x14E, SEEK_SET);
 		fputc(globalcksum >> 8, rom);
 		fputc(globalcksum & 0xFF, rom);
+		if (ferror(rom))
+			err(1, "Could not write global checksum");
 	}
 
-	fclose(rom);
+	if (fclose(rom) != 0)
+		err(1, "Could not complete ROM write");
 
 	return 0;
 }

src/fix/rgbfix.1

@@ -5,7 +5,7 @@
 .\"
 .\" SPDX-License-Identifier: MIT
 .\"
-.Dd January 26, 2018
+.Dd March 11, 2018
 .Dt RGBFIX 1
 .Os RGBDS Manual
 .Sh NAME
@@ -14,6 +14,7 @@
 .Sh SYNOPSIS
 .Nm rgbfix
 .Op Fl CcjsVv
+.Op Fl f Ar fix_spec
 .Op Fl i Ar game_id
 .Op Fl k Ar licensee_str
 .Op Fl l Ar licensee_id
@@ -46,6 +47,30 @@ If both this and the
 flag are set,
 .Fl C
 takes precedence.
+.It Fl f Ar fix_spec
+Fix certain header values that the Game Boy checks for correctness.
+Alternatively, intentionally trash these values by writing their binary inverse
+instead.
+.Ar fix_spec
+is a string containing any combination of the following characters:
+.Pp
+.Bl -tag -compact -width xx
+.It Cm l
+Fix the Nintendo logo
+.Pq Ad 0x104 Ns \(en Ns Ad 0x133 .
+.It Cm L
+Trash the Nintendo logo.
+.It Cm h
+Fix the header checksum
+.Pq Ad 0x14D .
+.It Cm H
+Trash the header checksum.
+.It Cm g
+Fix the global checksum
+.Pq Ad 0x14E Ns \(en Ns Ad 0x14F .
+.It Cm G
+Trash the global checksum.
+.El
 .It Fl i Ar game_id
 Set the game ID string
 .Pq Ad 0x13F Ns \(en Ns Ad 0x142
@@ -104,12 +129,8 @@ overlapping portion of the title.
 .It Fl V
 Print the version of the program and exit.
 .It Fl v
-Validate the header and fix checksums: the Nintendo character area
-.Pq Ad 0x104 Ns \(en Ns Ad 0x133 ,
-the header checksum
-.Pq Ad 0x14D ,
-and the global checksum
-.Pq Ad 0x14E Ns \(en Ns Ad 0x14F .
+Equivalent to
+.Fl f Cm lhg .
 .El
 .Sh EXAMPLES
 Most values in the ROM header are only cosmetic.

src/gbz80.7

@@ -5,7 +5,7 @@
 .\"
 .\" SPDX-License-Identifier: MIT
 .\"
-.Dd January 26, 2018
+.Dd February 23, 2018
 .Dt GBZ80 7
 .Os RGBDS Manual
 .Sh NAME
@@ -24,8 +24,10 @@ as destination can omit the destination as it is assumed it's register
 .Sy A .
 The following two lines have the same effect:
 .Pp
-.Dl OR A,B
-.Dl OR B
+.Bd -literal -offset indent
+OR A,B
+OR B
+.Ed
 .Pp
 .Sh LEGEND
 List of abbreviations used in this document.
@@ -1103,7 +1105,21 @@ Cycles: 3
 .Pp
 Bytes: 1
 .Pp
-Flags: None affected.
+Flags:
+.Bl -bullet -compact
+.It
+.Sy Z :
+Set from bit 7 of the popped low byte.
+.It
+.Sy N :
+Set from bit 6 of the popped low byte.
+.It
+.Sy H :
+Set from bit 5 of the popped low byte.
+.It
+.Sy C :
+Set from bit 4 of the popped low byte.
+.El
 .Ss POP r16
 Pop register
 .Ar r16
@@ -1117,7 +1133,15 @@ Flags: None affected.
 .Ss PUSH AF
 Push register
 .Sy AF
-into the stack.
+into the stack. The low byte's bit 7 corresponds to the
+.Sy Z
+flag, its bit 6 to the
+.Sy N
+flag, bit 5 to the
+.Sy H
+flag, and bit 4 to the
+.Sy C
+flag. Bits 3 to 0 are reset.
 .Pp
 Cycles: 4
 .Pp

src/gfx/gb.c

@@ -6,6 +6,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -31,23 +32,18 @@ void transpose_tiles(struct GBImage *gb, int width)
 	gb->data = newdata;
 }
 
-void png_to_gb(const struct PNGImage png, struct GBImage *gb)
+void raw_to_gb(const struct RawIndexedImage *raw_image, struct GBImage *gb)
 {
 	int x, y, byte;
-	png_byte index;
+	uint8_t index;
 
-	for (y = 0; y < png.height; y++) {
-		for (x = 0; x < png.width; x++) {
-			index = png.data[y][x];
+	for (y = 0; y < raw_image->height; y++) {
+		for (x = 0; x < raw_image->width; x++) {
+			index = raw_image->data[y][x];
 			index &= (1 << depth) - 1;
 
-			if (!gb->horizontal) {
-				byte = y * depth
-				     + x / 8 * png.height / 8 * 8 * depth;
-			} else {
-				byte = y * depth
-				     + x / 8 * png.height / 8 * 8 * depth;
-			}
+			byte = y * depth
+				+ x / 8 * raw_image->height / 8 * 8 * depth;
 			gb->data[byte] |= (index & 1) << (7 - x % 8);
 			if (depth == 2) {
 				gb->data[byte + 1] |=
@@ -57,18 +53,18 @@ void png_to_gb(const struct PNGImage png, struct GBImage *gb)
 	}
 
 	if (!gb->horizontal)
-		transpose_tiles(gb, png.width / 8);
+		transpose_tiles(gb, raw_image->width / 8);
 }
 
-void output_file(const struct Options opts, const struct GBImage gb)
+void output_file(const struct Options *opts, const struct GBImage *gb)
 {
 	FILE *f;
 
-	f = fopen(opts.outfile, "wb");
+	f = fopen(opts->outfile, "wb");
 	if (!f)
-		err(1, "Opening output file '%s' failed", opts.outfile);
+		err(1, "Opening output file '%s' failed", opts->outfile);
 
-	fwrite(gb.data, 1, gb.size - gb.trim * 8 * depth, f);
+	fwrite(gb->data, 1, gb->size - gb->trim * 8 * depth, f);
 
 	fclose(f);
 }
@@ -89,7 +85,7 @@ int get_tile_index(uint8_t *tile, uint8_t **tiles, int num_tiles, int tile_size)
 	return -1;
 }
 
-void create_tilemap(const struct Options opts, struct GBImage *gb,
+void create_tilemap(const struct Options *opts, struct GBImage *gb,
 		    struct Tilemap *tilemap)
 {
 	int i, j;
@@ -105,10 +101,15 @@ void create_tilemap(const struct Options opts, struct GBImage *gb,
 	tile_size = sizeof(uint8_t) * depth * 8;
 	gb_size = gb->size - (gb->trim * tile_size);
 	max_tiles = gb_size / tile_size;
-	tiles = malloc(sizeof(uint8_t *) * max_tiles);
+
+	/* If the input image doesn't fill the last tile, increase the count. */
+	if (gb_size > max_tiles * tile_size)
+		max_tiles++;
+
+	tiles = calloc(max_tiles, sizeof(uint8_t *));
 	num_tiles = 0;
 
-	tilemap->data = malloc(sizeof(uint8_t) * max_tiles);
+	tilemap->data = calloc(max_tiles, sizeof(uint8_t));
 	tilemap->size = 0;
 
 	gb_i = 0;
@@ -118,7 +119,7 @@ void create_tilemap(const struct Options opts, struct GBImage *gb,
 			tile[i] = gb->data[gb_i];
 			gb_i++;
 		}
-		if (opts.unique) {
+		if (opts->unique) {
 			index = get_tile_index(tile, tiles, num_tiles,
 					       tile_size);
 			if (index < 0) {
@@ -135,7 +136,7 @@ void create_tilemap(const struct Options opts, struct GBImage *gb,
 		tilemap->size++;
 	}
 
-	if (opts.unique) {
+	if (opts->unique) {
 		free(gb->data);
 		gb->data = malloc(tile_size * num_tiles);
 		for (i = 0; i < num_tiles; i++) {
@@ -152,43 +153,44 @@ void create_tilemap(const struct Options opts, struct GBImage *gb,
 	free(tiles);
 }
 
-void output_tilemap_file(const struct Options opts,
-			 const struct Tilemap tilemap)
+void output_tilemap_file(const struct Options *opts,
+			 const struct Tilemap *tilemap)
 {
 	FILE *f;
 
-	f = fopen(opts.mapfile, "wb");
+	f = fopen(opts->mapfile, "wb");
 	if (!f)
-		err(1, "Opening tilemap file '%s' failed", opts.mapfile);
+		err(1, "Opening tilemap file '%s' failed", opts->mapfile);
 
-	fwrite(tilemap.data, 1, tilemap.size, f);
+	fwrite(tilemap->data, 1, tilemap->size, f);
 	fclose(f);
 
-	if (opts.mapout)
-		free(opts.mapfile);
+	if (opts->mapout)
+		free(opts->mapfile);
 }
 
-void output_palette_file(const struct Options opts, const struct PNGImage png)
+void output_palette_file(const struct Options *opts,
+			 const struct RawIndexedImage *raw_image)
 {
 	FILE *f;
-	int i, colors, color;
-	png_color *palette;
+	int i, color;
+	uint8_t cur_bytes[2];
 
-	if (png_get_PLTE(png.png, png.info, &palette, &colors)) {
-		f = fopen(opts.palfile, "wb");
-		if (!f) {
-			err(1, "Opening palette file '%s' failed",
-			    opts.palfile);
-		}
-		for (i = 0; i < colors; i++) {
-			color = palette[i].blue >> 3 << 10
-			      | palette[i].green >> 3 << 5
-			      | palette[i].red >> 3;
-			fwrite(&color, 2, 1, f);
-		}
-		fclose(f);
+	f = fopen(opts->palfile, "wb");
+	if (!f)
+		err(1, "Opening palette file '%s' failed", opts->palfile);
+
+	for (i = 0; i < raw_image->num_colors; i++) {
+		color =
+			raw_image->palette[i].blue  >> 3 << 10 |
+			raw_image->palette[i].green >> 3 <<  5 |
+			raw_image->palette[i].red   >> 3;
+		cur_bytes[0] = color & 0xFF;
+		cur_bytes[1] = color >> 8;
+		fwrite(cur_bytes, 2, 1, f);
 	}
+	fclose(f);
 
-	if (opts.palout)
-		free(opts.palfile);
+	if (opts->palout)
+		free(opts->palfile);
 }

src/gfx/main.c

@@ -6,6 +6,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <png.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -26,7 +27,8 @@ int main(int argc, char *argv[])
 {
 	int ch, size;
 	struct Options opts = {0};
-	struct PNGImage png = {0};
+	struct ImageOptions png_options = {0};
+	struct RawIndexedImage *raw_image;
 	struct GBImage gb = {0};
 	struct Tilemap tilemap = {0};
 	char *ext;
@@ -51,6 +53,7 @@ int main(int argc, char *argv[])
 			break;
 		case 'F':
 			opts.hardfix = true;
+			/* fallthrough */
 		case 'f':
 			opts.fix = true;
 			break;
@@ -102,80 +105,89 @@ int main(int argc, char *argv[])
 
 	colors = 1 << depth;
 
-	input_png_file(opts, &png);
+	raw_image = input_png_file(&opts, &png_options);
 
-	png.mapfile = "";
-	png.palfile = "";
+	png_options.mapfile = "";
+	png_options.palfile = "";
 
-	get_text(&png);
-
-	if (png.horizontal != opts.horizontal) {
+	if (png_options.horizontal != opts.horizontal) {
 		if (opts.verbose)
 			warnx(errmsg, "horizontal");
 
 		if (opts.hardfix)
-			png.horizontal = opts.horizontal;
+			png_options.horizontal = opts.horizontal;
 	}
 
-	if (png.horizontal)
-		opts.horizontal = png.horizontal;
+	if (png_options.horizontal)
+		opts.horizontal = png_options.horizontal;
 
-	if (png.trim != opts.trim) {
+	if (png_options.trim != opts.trim) {
 		if (opts.verbose)
 			warnx(errmsg, "trim");
 
 		if (opts.hardfix)
-			png.trim = opts.trim;
+			png_options.trim = opts.trim;
 	}
 
-	if (png.trim)
-		opts.trim = png.trim;
+	if (png_options.trim)
+		opts.trim = png_options.trim;
 
-	if (opts.trim > png.width / 8 - 1) {
-		errx(1, "Trim (%i) for input png file '%s' too large (max: %i)",
-		     opts.trim, opts.infile, png.width / 8 - 1);
+	if (raw_image->width % 8) {
+		errx(1, "Input PNG file %s not sized correctly. The image's width must be a multiple of 8.",
+		     opts.infile);
+	}
+	if (raw_image->width / 8 > 1 && raw_image->height % 8) {
+		errx(1, "Input PNG file %s not sized correctly. If the image is more than 1 tile wide, its height must be a multiple of 8.",
+		     opts.infile);
 	}
 
-	if (strcmp(png.mapfile, opts.mapfile) != 0) {
+	if (opts.trim &&
+	    opts.trim > (raw_image->width / 8) * (raw_image->height / 8) - 1) {
+		errx(1, "Trim (%i) for input raw_image file '%s' too large (max: %i)",
+		     opts.trim, opts.infile,
+		     (raw_image->width / 8) * (raw_image->height / 8) - 1);
+	}
+
+	if (strcmp(png_options.mapfile, opts.mapfile) != 0) {
 		if (opts.verbose)
 			warnx(errmsg, "tilemap file");
 
 		if (opts.hardfix)
-			png.mapfile = opts.mapfile;
+			png_options.mapfile = opts.mapfile;
 	}
 	if (!*opts.mapfile)
-		opts.mapfile = png.mapfile;
+		opts.mapfile = png_options.mapfile;
 
-	if (png.mapout != opts.mapout) {
+	if (png_options.mapout != opts.mapout) {
 		if (opts.verbose)
 			warnx(errmsg, "tilemap file");
 
 		if (opts.hardfix)
-			png.mapout = opts.mapout;
+			png_options.mapout = opts.mapout;
 	}
-	if (png.mapout)
-		opts.mapout = png.mapout;
+	if (png_options.mapout)
+		opts.mapout = png_options.mapout;
 
-	if (strcmp(png.palfile, opts.palfile) != 0) {
+	if (strcmp(png_options.palfile, opts.palfile) != 0) {
 		if (opts.verbose)
 			warnx(errmsg, "palette file");
 
 		if (opts.hardfix)
-			png.palfile = opts.palfile;
+			png_options.palfile = opts.palfile;
 	}
 	if (!*opts.palfile)
-		opts.palfile = png.palfile;
+		opts.palfile = png_options.palfile;
 
-	if (png.palout != opts.palout) {
+	if (png_options.palout != opts.palout) {
 		if (opts.verbose)
 			warnx(errmsg, "palette file");
 
 		if (opts.hardfix)
-			png.palout = opts.palout;
+			png_options.palout = opts.palout;
 	}
 
-	if (png.palout)
-		opts.palout = png.palout;
+	if (png_options.palout)
+		opts.palout = png_options.palout;
 
 	if (!*opts.mapfile && opts.mapout) {
 		ext = strrchr(opts.infile, '.');
@@ -209,31 +221,29 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	gb.size = png.width * png.height * depth / 8;
+	gb.size = raw_image->width * raw_image->height * depth / 8;
 	gb.data = calloc(gb.size, 1);
 	gb.trim = opts.trim;
 	gb.horizontal = opts.horizontal;
 
 	if (*opts.outfile || *opts.mapfile) {
-		png_to_gb(png, &gb);
-		create_tilemap(opts, &gb, &tilemap);
+		raw_to_gb(raw_image, &gb);
+		create_tilemap(&opts, &gb, &tilemap);
 	}
 
 	if (*opts.outfile)
-		output_file(opts, gb);
+		output_file(&opts, &gb);
 
 	if (*opts.mapfile)
-		output_tilemap_file(opts, tilemap);
+		output_tilemap_file(&opts, &tilemap);
 
 	if (*opts.palfile)
-		output_palette_file(opts, png);
+		output_palette_file(&opts, raw_image);
 
-	if (opts.fix || opts.debug) {
-		set_text(&png);
-		output_png_file(opts, &png);
-	}
+	if (opts.fix || opts.debug)
+		output_png_file(&opts, &png_options, raw_image);
 
-	free_png_data(&png);
+	destroy_raw_image(&raw_image);
 	free(gb.data);
 
 	return 0;

src/gfx/makepng.c

@@ -6,25 +6,150 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <png.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "gfx/main.h"
 
-void input_png_file(const struct Options opts, struct PNGImage *img)
+static void initialize_png(struct PNGImage *img, FILE *f);
+static struct RawIndexedImage *indexed_png_to_raw(struct PNGImage *img);
+static struct RawIndexedImage *grayscale_png_to_raw(struct PNGImage *img);
+static struct RawIndexedImage *truecolor_png_to_raw(struct PNGImage *img);
+static void get_text(const struct PNGImage *img,
+		     struct ImageOptions *png_options);
+static void set_text(const struct PNGImage *img,
+		     const struct ImageOptions *png_options);
+static void free_png_data(const struct PNGImage *png);
+
+struct RawIndexedImage *input_png_file(const struct Options *opts,
+				       struct ImageOptions *png_options)
+{
+	struct PNGImage img;
+	struct RawIndexedImage *raw_image;
+	FILE *f;
+
+	f = fopen(opts->infile, "rb");
+	if (!f)
+		err(1, "Opening input png file '%s' failed", opts->infile);
+
+	initialize_png(&img, f);
+
+	if (img.depth != depth) {
+		if (opts->verbose) {
+			warnx("Image bit depth is not %i (is %i).",
+			      depth, img.depth);
+		}
+	}
+
+	switch (img.type) {
+	case PNG_COLOR_TYPE_PALETTE:
+		raw_image = indexed_png_to_raw(&img); break;
+	case PNG_COLOR_TYPE_GRAY:
+	case PNG_COLOR_TYPE_GRAY_ALPHA:
+		raw_image = grayscale_png_to_raw(&img); break;
+	case PNG_COLOR_TYPE_RGB:
+	case PNG_COLOR_TYPE_RGB_ALPHA:
+		raw_image = truecolor_png_to_raw(&img); break;
+	default:
+		/* Shouldn't happen, but might as well handle just in case. */
+		errx(1, "Input PNG file is of invalid color type.");
+	}
+
+	get_text(&img, png_options);
+
+	png_destroy_read_struct(&img.png, &img.info, NULL);
+	fclose(f);
+	free_png_data(&img);
+
+	return raw_image;
+}
+
+void output_png_file(const struct Options *opts,
+		     const struct ImageOptions *png_options,
+		     const struct RawIndexedImage *raw_image)
 {
 	FILE *f;
-	int i, y, num_trans;
-	bool has_palette = false;
-	png_byte *trans_alpha;
-	png_color_16 *trans_values;
-	bool *full_alpha;
-	png_color *palette;
+	char *outfile;
+	struct PNGImage img;
+	png_color *png_palette;
+	int i;
 
-	f = fopen(opts.infile, "rb");
+	/*
+	 * TODO: Variable outfile is for debugging purposes. Eventually,
+	 * opts.infile will be used directly.
+	 */
+	if (opts->debug) {
+		outfile = malloc(strlen(opts->infile) + 5);
+		strcpy(outfile, opts->infile);
+		strcat(outfile, ".out");
+	} else {
+		outfile = opts->infile;
+	}
+
+	f = fopen(outfile, "wb");
 	if (!f)
-		err(1, "Opening input png file '%s' failed", opts.infile);
+		err(1, "Opening output png file '%s' failed", outfile);
 
+	img.png = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+					  NULL, NULL, NULL);
+	if (!img.png)
+		errx(1, "Creating png structure failed");
+
+	img.info = png_create_info_struct(img.png);
+	if (!img.info)
+		errx(1, "Creating png info structure failed");
+
+	if (setjmp(png_jmpbuf(img.png)))
+		exit(1);
+
+	png_init_io(img.png, f);
+
+	png_set_IHDR(img.png, img.info, raw_image->width, raw_image->height,
+		     8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
+		     PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+	png_palette = malloc(sizeof(png_color *) * raw_image->num_colors);
+	for (i = 0; i < raw_image->num_colors; i++) {
+		png_palette[i].red   = raw_image->palette[i].red;
+		png_palette[i].green = raw_image->palette[i].green;
+		png_palette[i].blue  = raw_image->palette[i].blue;
+	}
+	png_set_PLTE(img.png, img.info, png_palette, raw_image->num_colors);
+	free(png_palette);
+
+	if (opts->fix)
+		set_text(&img, png_options);
+
+	png_write_info(img.png, img.info);
+
+	png_write_image(img.png, (png_byte **) raw_image->data);
+	png_write_end(img.png, NULL);
+
+	png_destroy_write_struct(&img.png, &img.info);
+	fclose(f);
+
+	if (opts->debug)
+		free(outfile);
+}
+
+void destroy_raw_image(struct RawIndexedImage **raw_image_ptr_ptr)
+{
+	int y;
+	struct RawIndexedImage *raw_image = *raw_image_ptr_ptr;
+
+	for (y = 0; y < raw_image->height; y++)
+		free(raw_image->data[y]);
+
+	free(raw_image->data);
+	free(raw_image->palette);
+	free(raw_image);
+	*raw_image_ptr_ptr = NULL;
+}
+
+static void initialize_png(struct PNGImage *img, FILE *f)
+{
 	img->png = png_create_read_struct(PNG_LIBPNG_VER_STRING,
 					  NULL, NULL, NULL);
 	if (!img->png)
@@ -34,7 +159,6 @@ void input_png_file(const struct Options opts, struct PNGImage *img)
 	if (!img->info)
 		errx(1, "Creating png info structure failed");
 
-	/* TODO: Better error handling here? */
 	if (setjmp(png_jmpbuf(img->png)))
 		exit(1);
 
@@ -46,125 +170,415 @@ void input_png_file(const struct Options opts, struct PNGImage *img)
 	img->height = png_get_image_height(img->png, img->info);
 	img->depth  = png_get_bit_depth(img->png, img->info);
 	img->type   = png_get_color_type(img->png, img->info);
+}
 
-	if (img->type & PNG_COLOR_MASK_ALPHA)
-		png_set_strip_alpha(img->png);
+static void read_png(struct PNGImage *img);
+static struct RawIndexedImage *create_raw_image(int width, int height,
+						int num_colors);
+static void set_raw_image_palette(struct RawIndexedImage *raw_image,
+				  const png_color *palette, int num_colors);
 
-	if (img->depth != depth) {
-		if (opts.verbose) {
-			warnx("Image bit depth is not %i (is %i).", depth,
-			      img->depth);
-		}
-	}
+static struct RawIndexedImage *indexed_png_to_raw(struct PNGImage *img)
+{
+	struct RawIndexedImage *raw_image;
+	png_color *palette;
+	int colors_in_PLTE;
+	int colors_in_new_palette;
+	png_byte *trans_alpha;
+	int num_trans;
+	png_color_16 *trans_color;
+	png_color *original_palette;
+	uint8_t *old_to_new_palette;
+	int i, x, y;
 
-	if (img->type == PNG_COLOR_TYPE_GRAY) {
-		if (img->depth < 8)
-			png_set_expand_gray_1_2_4_to_8(img->png);
+	if (img->depth < 8)
+		png_set_packing(img->png);
 
-		png_set_gray_to_rgb(img->png);
-	} else {
-		if (img->depth < 8)
-			png_set_expand_gray_1_2_4_to_8(img->png);
+	png_get_PLTE(img->png, img->info, &palette, &colors_in_PLTE);
 
-		has_palette = png_get_PLTE(img->png, img->info, &palette,
-					   &colors);
-	}
+	raw_image = create_raw_image(img->width, img->height, colors);
 
+	/*
+	 * Transparent palette entries are removed, and the palette is collapsed.
+	 * Transparent pixels are then replaced with palette index 0.
+	 * This way, an indexed PNG can contain transparent pixels in *addition*
+	 * to 4 normal colors.
+	 */
 	if (png_get_tRNS(img->png, img->info, &trans_alpha, &num_trans,
-			 &trans_values)) {
-		if (img->type == PNG_COLOR_TYPE_PALETTE) {
-			full_alpha = malloc(sizeof(bool) * num_trans);
+			 &trans_color)) {
+		original_palette = palette;
+		palette = malloc(sizeof(png_color) * colors_in_PLTE);
+		colors_in_new_palette = 0;
+		old_to_new_palette = malloc(sizeof(uint8_t) * colors_in_PLTE);
 
-			for (i = 0; i < num_trans; i++) {
-				if (trans_alpha[i] > 0)
-					full_alpha[i] = false;
-				else
-					full_alpha[i] = true;
+		for (i = 0; i < num_trans; i++) {
+			if (trans_alpha[i] == 0) {
+				old_to_new_palette[i] = 0;
+			} else {
+				old_to_new_palette[i] = colors_in_new_palette;
+				palette[colors_in_new_palette++] =
+					original_palette[i];
 			}
-
-			for (i = 0; i < num_trans; i++) {
-				if (full_alpha[i]) {
-					palette[i].red   = 0xFF;
-					palette[i].green = 0x00;
-					palette[i].blue  = 0xFF;
-					/*
-					 * Set to the lightest color in the
-					 * palette.
-					 */
-				}
-			}
-
-			free(full_alpha);
-		} else {
-			/* Set to the lightest color in the image. */
+		}
+		for (i = num_trans; i < colors_in_PLTE; i++) {
+			old_to_new_palette[i] = colors_in_new_palette;
+			palette[colors_in_new_palette++] = original_palette[i];
 		}
 
-		png_free_data(img->png, img->info, PNG_FREE_TRNS, -1);
-	}
+		if (colors_in_new_palette != colors_in_PLTE) {
+			palette = realloc(palette,
+					  sizeof(png_color) *
+					  colors_in_new_palette);
+		}
 
-	if (has_palette) {
-		/* Make sure palette only has the amount of colors you want. */
-	} else {
 		/*
-		 * Eventually when this copies colors from the image itself,
-		 * make sure order is lightest to darkest.
+		 * Setting and validating palette before reading
+		 * allows us to error out *before* doing the data
+		 * transformation if the palette is too long.
 		 */
-		palette = malloc(sizeof(png_color) * colors);
+		set_raw_image_palette(raw_image, palette,
+				      colors_in_new_palette);
+		read_png(img);
 
-		if (strcmp(opts.infile, "rgb.png") == 0) {
-			palette[0].red   = 0xFF;
-			palette[0].green = 0xEF;
-			palette[0].blue  = 0xFF;
+		for (y = 0; y < img->height; y++) {
+			for (x = 0; x < img->width; x++) {
+				raw_image->data[y][x] =
+					old_to_new_palette[img->data[y][x]];
+			}
+		}
 
-			palette[1].red   = 0xF7;
-			palette[1].green = 0xF7;
-			palette[1].blue  = 0x8C;
+		free(old_to_new_palette);
+	} else {
+		set_raw_image_palette(raw_image, palette, colors_in_PLTE);
+		read_png(img);
 
-			palette[2].red   = 0x94;
-			palette[2].green = 0x94;
-			palette[2].blue  = 0xC6;
-
-			palette[3].red   = 0x39;
-			palette[3].green = 0x39;
-			palette[3].blue  = 0x84;
-		} else {
-			palette[0].red   = 0xFF;
-			palette[0].green = 0xFF;
-			palette[0].blue  = 0xFF;
-
-			palette[1].red   = 0xA9;
-			palette[1].green = 0xA9;
-			palette[1].blue  = 0xA9;
-
-			palette[2].red   = 0x55;
-			palette[2].green = 0x55;
-			palette[2].blue  = 0x55;
-
-			palette[3].red   = 0x00;
-			palette[3].green = 0x00;
-			palette[3].blue  = 0x00;
+		for (y = 0; y < img->height; y++) {
+			for (x = 0; x < img->width; x++)
+				raw_image->data[y][x] = img->data[y][x];
 		}
 	}
 
-	/*
-	 * Also unfortunately, this sets it at 8 bit, and I can't find any
-	 * option to reduce to 2 or 1 bit.
-	 */
-#if PNG_LIBPNG_VER < 10402
-	png_set_dither(img->png, palette, colors, colors, NULL, 1);
-#else
-	png_set_quantize(img->png, palette, colors, colors, NULL, 1);
-#endif
+	return raw_image;
+}
 
-	if (!has_palette) {
-		png_set_PLTE(img->png, img->info, palette, colors);
-		free(palette);
+static struct RawIndexedImage *grayscale_png_to_raw(struct PNGImage *img)
+{
+	if (img->depth < 8)
+		png_set_expand_gray_1_2_4_to_8(img->png);
+
+	png_set_gray_to_rgb(img->png);
+	return truecolor_png_to_raw(img);
+}
+
+static void rgba_png_palette(struct PNGImage *img,
+			     png_color **palette_ptr_ptr, int *num_colors);
+static struct RawIndexedImage
+	*processed_rgba_png_to_raw(const struct PNGImage *img,
+				   const png_color *palette,
+				   int colors_in_palette);
+
+static struct RawIndexedImage *truecolor_png_to_raw(struct PNGImage *img)
+{
+	struct RawIndexedImage *raw_image;
+	png_color *palette;
+	int colors_in_palette;
+
+	if (img->depth == 16) {
+#if PNG_LIBPNG_VER >= 10504
+		png_set_scale_16(img->png);
+#else
+		png_set_strip_16(img->png);
+#endif
 	}
 
+	if (!(img->type & PNG_COLOR_MASK_ALPHA)) {
+		if (png_get_valid(img->png, img->info, PNG_INFO_tRNS))
+			png_set_tRNS_to_alpha(img->png);
+		else
+			png_set_add_alpha(img->png, 0xFF, PNG_FILLER_AFTER);
+	}
+
+	read_png(img);
+
+	rgba_png_palette(img, &palette, &colors_in_palette);
+	raw_image = processed_rgba_png_to_raw(img, palette, colors_in_palette);
+
+	free(palette);
+
+	return raw_image;
+}
+
+static void rgba_PLTE_palette(struct PNGImage *img,
+			      png_color **palette_ptr_ptr, int *num_colors);
+static void rgba_build_palette(struct PNGImage *img,
+			       png_color **palette_ptr_ptr, int *num_colors);
+
+static void rgba_png_palette(struct PNGImage *img,
+			     png_color **palette_ptr_ptr, int *num_colors)
+{
+	if (png_get_valid(img->png, img->info, PNG_INFO_PLTE))
+		rgba_PLTE_palette(img, palette_ptr_ptr, num_colors);
+	else
+		rgba_build_palette(img, palette_ptr_ptr, num_colors);
+}
+
+static void rgba_PLTE_palette(struct PNGImage *img,
+			      png_color **palette_ptr_ptr, int *num_colors)
+{
+	png_get_PLTE(img->png, img->info, palette_ptr_ptr, num_colors);
 	/*
-	 * If other useless chunks exist (sRGB, bKGD, pHYs, gAMA, cHRM, iCCP,
-	 * etc.) offer to remove?
+	 * Lets us free the palette manually instead of leaving it to libpng,
+	 * which lets us handle a PLTE and a built palette the same way.
 	 */
+	png_data_freer(img->png, img->info,
+		       PNG_USER_WILL_FREE_DATA, PNG_FREE_PLTE);
+}
+
+static void update_built_palette(png_color *palette,
+				 const png_color *pixel_color, png_byte alpha,
+				 int *num_colors, bool *only_grayscale);
+static int fit_grayscale_palette(png_color *palette, int *num_colors);
+static void order_color_palette(png_color *palette, int num_colors);
+
+static void rgba_build_palette(struct PNGImage *img,
+			       png_color **palette_ptr_ptr, int *num_colors)
+{
+	png_color *palette;
+	int y, value_index;
+	png_color cur_pixel_color;
+	png_byte cur_alpha;
+	bool only_grayscale = true;
+
+	/*
+	 * By filling the palette up with black by default, if the image
+	 * doesn't have enough colors, the palette gets padded with black.
+	 */
+	*palette_ptr_ptr = calloc(colors, sizeof(png_color));
+	palette = *palette_ptr_ptr;
+	*num_colors = 0;
+
+	for (y = 0; y < img->height; y++) {
+		value_index = 0;
+		while (value_index < img->width * 4) {
+			cur_pixel_color.red   = img->data[y][value_index++];
+			cur_pixel_color.green = img->data[y][value_index++];
+			cur_pixel_color.blue  = img->data[y][value_index++];
+			cur_alpha = img->data[y][value_index++];
+
+			update_built_palette(palette, &cur_pixel_color,
+					     cur_alpha,
+					     num_colors, &only_grayscale);
+		}
+	}
+
+	/* In order not to count 100% transparent images as grayscale. */
+	only_grayscale = *num_colors ? only_grayscale : false;
+
+	if (!only_grayscale || !fit_grayscale_palette(palette, num_colors))
+		order_color_palette(palette, *num_colors);
+}
+
+static void update_built_palette(png_color *palette,
+				 const png_color *pixel_color, png_byte alpha,
+				 int *num_colors, bool *only_grayscale)
+{
+	bool color_exists;
+	png_color cur_palette_color;
+	int i;
+
+	/*
+	 * Transparent pixels don't count toward the palette,
+	 * as they'll be replaced with color #0 later.
+	 */
+	if (alpha == 0)
+		return;
+
+	if (*only_grayscale && !(pixel_color->red == pixel_color->green &&
+				 pixel_color->red == pixel_color->blue)) {
+		*only_grayscale = false;
+	}
+
+	color_exists = false;
+	for (i = 0; i < *num_colors; i++) {
+		cur_palette_color = palette[i];
+		if (pixel_color->red   == cur_palette_color.red   &&
+		    pixel_color->green == cur_palette_color.green &&
+		    pixel_color->blue  == cur_palette_color.blue) {
+			color_exists = true;
+			break;
+		}
+	}
+	if (!color_exists) {
+		if (*num_colors == colors) {
+			err(1, "Too many colors in input PNG file to fit into a %d-bit palette (max %d).",
+			    depth, colors);
+		}
+		palette[*num_colors] = *pixel_color;
+		(*num_colors)++;
+	}
+}
+
+static int fit_grayscale_palette(png_color *palette, int *num_colors)
+{
+	int interval = 256 / colors;
+	png_color *fitted_palette = malloc(sizeof(png_color) * colors);
+	bool *set_indices = calloc(colors, sizeof(bool));
+	int i, shade_index;
+
+	fitted_palette[0].red   = 0xFF;
+	fitted_palette[0].green = 0xFF;
+	fitted_palette[0].blue  = 0xFF;
+	fitted_palette[colors - 1].red   = 0;
+	fitted_palette[colors - 1].green = 0;
+	fitted_palette[colors - 1].blue  = 0;
+	if (colors == 4) {
+		fitted_palette[1].red   = 0xA9;
+		fitted_palette[1].green = 0xA9;
+		fitted_palette[1].blue  = 0xA9;
+		fitted_palette[2].red   = 0x55;
+		fitted_palette[2].green = 0x55;
+		fitted_palette[2].blue  = 0x55;
+	}
+
+	for (i = 0; i < *num_colors; i++) {
+		shade_index = colors - 1 - palette[i].red / interval;
+		if (set_indices[shade_index]) {
+			free(fitted_palette);
+			free(set_indices);
+			return false;
+		}
+		fitted_palette[shade_index] = palette[i];
+		set_indices[shade_index] = true;
+	}
+
+	for (i = 0; i < colors; i++)
+		palette[i] = fitted_palette[i];
+
+	*num_colors = colors;
+
+	free(fitted_palette);
+	free(set_indices);
+	return true;
+}
+
+/* A combined struct is needed to sort csolors in order of luminance. */
+struct ColorWithLuminance {
+	png_color color;
+	int luminance;
+};
+
+static int compare_luminance(const void *a, const void *b)
+{
+	const struct ColorWithLuminance *x, *y;
+
+	x = (const struct ColorWithLuminance *)a;
+	y = (const struct ColorWithLuminance *)b;
+
+	return y->luminance - x->luminance;
+}
+
+static void order_color_palette(png_color *palette, int num_colors)
+{
+	int i;
+	struct ColorWithLuminance *palette_with_luminance =
+		malloc(sizeof(struct ColorWithLuminance) * num_colors);
+
+	for (i = 0; i < num_colors; i++) {
+		/*
+		 * Normally this would be done with floats, but since it's only
+		 * used for comparison, we might as well use integer math.
+		 */
+		palette_with_luminance[i].color = palette[i];
+		palette_with_luminance[i].luminance = 2126 * palette[i].red   +
+						      7152 * palette[i].green +
+						       722 * palette[i].blue;
+	}
+	qsort(palette_with_luminance, num_colors,
+	      sizeof(struct ColorWithLuminance), compare_luminance);
+	for (i = 0; i < num_colors; i++)
+		palette[i] = palette_with_luminance[i].color;
+
+	free(palette_with_luminance);
+}
+
+static void put_raw_image_pixel(struct RawIndexedImage *raw_image,
+				const struct PNGImage *img,
+				int *value_index, int x, int y,
+				const png_color *palette,
+				int colors_in_palette);
+
+static struct RawIndexedImage
+	*processed_rgba_png_to_raw(const struct PNGImage *img,
+				   const png_color *palette,
+				   int colors_in_palette)
+{
+	struct RawIndexedImage *raw_image;
+	int x, y, value_index;
+
+	raw_image = create_raw_image(img->width, img->height, colors);
+
+	set_raw_image_palette(raw_image, palette, colors_in_palette);
+
+	for (y = 0; y < img->height; y++) {
+		x = raw_image->width - 1;
+		value_index = img->width * 4 - 1;
+
+		while (x >= 0) {
+			put_raw_image_pixel(raw_image, img,
+					    &value_index, x, y,
+					    palette, colors_in_palette);
+			x--;
+		}
+	}
+
+	return raw_image;
+}
+
+static uint8_t palette_index_of(const png_color *palette,
+				int num_colors, const png_color *color);
+
+static void put_raw_image_pixel(struct RawIndexedImage *raw_image,
+				const struct PNGImage *img,
+				int *value_index, int x, int y,
+				const png_color *palette,
+				int colors_in_palette)
+{
+	png_color pixel_color;
+	png_byte alpha;
+
+	alpha = img->data[y][*value_index];
+	if (alpha == 0) {
+		raw_image->data[y][x] = 0;
+		*value_index -= 4;
+	} else {
+		(*value_index)--;
+		pixel_color.blue  = img->data[y][(*value_index)--];
+		pixel_color.green = img->data[y][(*value_index)--];
+		pixel_color.red   = img->data[y][(*value_index)--];
+		raw_image->data[y][x] = palette_index_of(palette,
+							 colors_in_palette,
+							 &pixel_color);
+	}
+}
+
+static uint8_t palette_index_of(const png_color *palette,
+				int num_colors, const png_color *color)
+{
+	uint8_t i;
+
+	for (i = 0; i < num_colors; i++) {
+		if (palette[i].red   == color->red   &&
+		    palette[i].green == color->green &&
+		    palette[i].blue  == color->blue) {
+			return i;
+		}
+	}
+	errx(1, "The input PNG file contains colors that don't appear in its embedded palette.");
+}
+
+static void read_png(struct PNGImage *img)
+{
+	int y;
 
 	png_read_update_info(img->png, img->info);
 
@@ -174,35 +588,78 @@ void input_png_file(const struct Options opts, struct PNGImage *img)
 
 	png_read_image(img->png, img->data);
 	png_read_end(img->png, img->info);
-
-	fclose(f);
 }
 
-void get_text(struct PNGImage *png)
+static struct RawIndexedImage *create_raw_image(int width, int height,
+						int num_colors)
+{
+	struct RawIndexedImage *raw_image;
+	int y;
+
+	raw_image = malloc(sizeof(struct RawIndexedImage));
+
+	raw_image->width = width;
+	raw_image->height = height;
+	raw_image->num_colors = num_colors;
+
+	raw_image->palette = malloc(sizeof(struct RGBColor) * num_colors);
+
+	raw_image->data = malloc(sizeof(uint8_t *) * height);
+	for (y = 0; y < height; y++)
+		raw_image->data[y] = malloc(sizeof(uint8_t) * width);
+
+	return raw_image;
+}
+
+static void set_raw_image_palette(struct RawIndexedImage *raw_image,
+				  const png_color *palette, int num_colors)
+{
+	int i;
+
+	if (num_colors > raw_image->num_colors) {
+		errx(1, "Too many colors in input PNG file's palette to fit into a %d-bit palette (%d in input palette, max %d).",
+		     raw_image->num_colors >> 1,
+		     num_colors, raw_image->num_colors);
+	}
+
+	for (i = 0; i < num_colors; i++) {
+		raw_image->palette[i].red   = palette[i].red;
+		raw_image->palette[i].green = palette[i].green;
+		raw_image->palette[i].blue  = palette[i].blue;
+	}
+	for (i = num_colors; i < raw_image->num_colors; i++) {
+		raw_image->palette[i].red   = 0;
+		raw_image->palette[i].green = 0;
+		raw_image->palette[i].blue  = 0;
+	}
+}
+
+static void get_text(const struct PNGImage *img,
+		     struct ImageOptions *png_options)
 {
 	png_text *text;
 	int i, numtxts, numremoved;
 
-	png_get_text(png->png, png->info, &text, &numtxts);
+	png_get_text(img->png, img->info, &text, &numtxts);
 	for (i = 0; i < numtxts; i++) {
 		if (strcmp(text[i].key, "h") == 0 && !*text[i].text) {
-			png->horizontal = true;
-			png_free_data(png->png, png->info, PNG_FREE_TEXT, i);
+			png_options->horizontal = true;
+			png_free_data(img->png, img->info, PNG_FREE_TEXT, i);
 		} else if (strcmp(text[i].key, "x") == 0) {
-			png->trim = strtoul(text[i].text, NULL, 0);
-			png_free_data(png->png, png->info, PNG_FREE_TEXT, i);
+			png_options->trim = strtoul(text[i].text, NULL, 0);
+			png_free_data(img->png, img->info, PNG_FREE_TEXT, i);
 		} else if (strcmp(text[i].key, "t") == 0) {
-			png->mapfile = text[i].text;
-			png_free_data(png->png, png->info, PNG_FREE_TEXT, i);
+			png_options->mapfile = text[i].text;
+			png_free_data(img->png, img->info, PNG_FREE_TEXT, i);
 		} else if (strcmp(text[i].key, "T") == 0 && !*text[i].text) {
-			png->mapout = true;
-			png_free_data(png->png, png->info, PNG_FREE_TEXT, i);
+			png_options->mapout = true;
+			png_free_data(img->png, img->info, PNG_FREE_TEXT, i);
 		} else if (strcmp(text[i].key, "p") == 0) {
-			png->palfile = text[i].text;
-			png_free_data(png->png, png->info, PNG_FREE_TEXT, i);
+			png_options->palfile = text[i].text;
+			png_free_data(img->png, img->info, PNG_FREE_TEXT, i);
 		} else if (strcmp(text[i].key, "P") == 0 && !*text[i].text) {
-			png->palout = true;
-			png_free_data(png->png, png->info, PNG_FREE_TEXT, i);
+			png_options->palout = true;
+			png_free_data(img->png, img->info, PNG_FREE_TEXT, i);
 		}
 	}
 
@@ -218,106 +675,64 @@ void get_text(struct PNGImage *png)
 		text[i].text = text[i + numremoved].text;
 		text[i].compression = text[i + numremoved].compression;
 	}
-	png_set_text(png->png, png->info, text, numtxts - numremoved);
+	png_set_text(img->png, img->info, text, numtxts - numremoved);
 }
 
-void set_text(const struct PNGImage *png)
+static void set_text(const struct PNGImage *img,
+		     const struct ImageOptions *png_options)
 {
 	png_text *text;
 	char buffer[3];
 
 	text = malloc(sizeof(png_text));
 
-	if (png->horizontal) {
+	if (png_options->horizontal) {
 		text[0].key = "h";
 		text[0].text = "";
 		text[0].compression = PNG_TEXT_COMPRESSION_NONE;
-		png_set_text(png->png, png->info, text, 1);
+		png_set_text(img->png, img->info, text, 1);
 	}
-	if (png->trim) {
+	if (png_options->trim) {
 		text[0].key = "x";
-		snprintf(buffer, 3, "%d", png->trim);
+		snprintf(buffer, 3, "%d", png_options->trim);
 		text[0].text = buffer;
 		text[0].compression = PNG_TEXT_COMPRESSION_NONE;
-		png_set_text(png->png, png->info, text, 1);
+		png_set_text(img->png, img->info, text, 1);
 	}
-	if (*png->mapfile) {
+	if (*png_options->mapfile) {
 		text[0].key = "t";
 		text[0].text = "";
 		text[0].compression = PNG_TEXT_COMPRESSION_NONE;
-		png_set_text(png->png, png->info, text, 1);
+		png_set_text(img->png, img->info, text, 1);
 	}
-	if (png->mapout) {
+	if (png_options->mapout) {
 		text[0].key = "T";
 		text[0].text = "";
 		text[0].compression = PNG_TEXT_COMPRESSION_NONE;
-		png_set_text(png->png, png->info, text, 1);
+		png_set_text(img->png, img->info, text, 1);
 	}
-	if (*png->palfile) {
+	if (*png_options->palfile) {
 		text[0].key = "p";
 		text[0].text = "";
 		text[0].compression = PNG_TEXT_COMPRESSION_NONE;
-		png_set_text(png->png, png->info, text, 1);
+		png_set_text(img->png, img->info, text, 1);
 	}
-	if (png->palout) {
+	if (png_options->palout) {
 		text[0].key = "P";
 		text[0].text = "";
 		text[0].compression = PNG_TEXT_COMPRESSION_NONE;
-		png_set_text(png->png, png->info, text, 1);
+		png_set_text(img->png, img->info, text, 1);
 	}
 
 	free(text);
 }
 
-void output_png_file(const struct Options opts, const struct PNGImage *png)
-{
-	FILE *f;
-	char *outfile;
-	png_struct *img;
-
-	/*
-	 * TODO: Variable outfile is for debugging purposes. Eventually,
-	 * opts.infile will be used directly.
-	 */
-	if (opts.debug) {
-		outfile = malloc(strlen(opts.infile) + 5);
-		strcpy(outfile, opts.infile);
-		strcat(outfile, ".out");
-	} else {
-		outfile = opts.infile;
-	}
-
-	f = fopen(outfile, "wb");
-	if (!f)
-		err(1, "Opening output png file '%s' failed", outfile);
-
-	img = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-	if (!img)
-		errx(1, "Creating png structure failed");
-
-	/* TODO: Better error handling here? */
-	if (setjmp(png_jmpbuf(img)))
-		exit(1);
-
-	png_init_io(img, f);
-
-	png_write_info(img, png->info);
-
-	png_write_image(img, png->data);
-	png_write_end(img, NULL);
-
-	fclose(f);
-
-	if (opts.debug)
-		free(outfile);
-}
-
-void free_png_data(const struct PNGImage *png)
+static void free_png_data(const struct PNGImage *img)
 {
 	int y;
 
-	for (y = 0; y < png->height; y++)
-		free(png->data[y]);
+	for (y = 0; y < img->height; y++)
+		free(img->data[y]);
 
-	free(png->data);
+	free(img->data);
 }

src/gfx/rgbgfx.1

@@ -24,7 +24,28 @@
 The
 .Nm
 program converts PNG images into the Nintendo Game Boy's planar tile format.
-The arguments are as follows:
+
+The resulting colors and their palette indices are determined differently
+depending on the input PNG file:
+.Bl -dash -width Ds
+.It
+If the file has an embedded palette, that palette's color and order are used.
+.It
+If not, and the image only contains shades of gray, rgbgfx maps them to the
+indices appropriate for each shade. Any undetermined indices are set to
+respective default shades of gray. For example: if the bit depth is 2 and the
+image contains light gray and black, they become the second and fourth colors -
+and the first and third colors get set to default white and dark gray. If the
+image has multiple shades that map to the same index, the palette is instead
+determined as if the image had color.
+.It
+If the image has color (or the grayscale method failed), the colors are sorted
+from lightest to darkest.
+.El
+
+The input image may not contain more colors than the selected bit depth
+allows. Transparent pixels are set to palette index 0.
+.Sh ARGUMENTS
 .Bl -tag -width Ds
 .It Fl D
 Debug features are enabled.
@@ -33,24 +54,25 @@ Fix the input PNG file to be a correctly indexed image.
 .It Fl F
 Same as
 .Fl f ,
-but additionally, the input PNG file is fixed to have its parameters match the
-command line's parameters.
+but additionally, the supplied command line parameters are saved within the PNG
+and will be loaded and automatically used next time.
 .It Fl d Ar depth
-The bitdepth of the output image (either 1 or 2).
-By default, the bitdepth is 2 (two bits per pixel).
+The bit depth of the output image (either 1 or 2).
+By default, the bit depth is 2 (two bits per pixel).
 .It Fl h
 Lay out tiles horizontally rather than vertically.
 .It Fl o Ar outfile
 The name of the output file.
 .It Fl p Ar palfile
-Raw bytes (8 bytes for two bits per pixel, 4 bytes for one bit per pixel)
-containing the RGB15 values in the little-endian byte order and then ordered
-from lightest to darkest.
+Output the image's palette in standard GBC palette format - bytes (8 bytes for
+two bits per pixel, 4 bytes for one bit per pixel) containing the RGB15 values
+in little-endian byte order. If the palette contains too few colors, the
+remaining entries are set to black.
 .It Fl P
 Same as
 .Fl p ,
-but the pallete file output name is made by taking the input filename,
-removing the file extension, and appending
+but the palette file output name is made by taking the input PNG file's
+filename, removing the file extension, and appending
 .Pa .pal .
 .It Fl t Ar mapfile
 If any tiles are the same, don't place the repeat tiles in the output file, and
@@ -73,7 +95,7 @@ the PNG file don't match.
 Trim the end of the output file by this many tiles.
 .El
 .Sh EXAMPLES
-The following will take a PNG file with a bitdepth of 1, 2, or 8, and output
+The following will take a PNG file with a bit depth of 1, 2, or 8, and output
 planar 2bpp data:
 .Pp
 .D1 $ rgbgfx -o out.2bpp in.png

src/link/assign.c

@@ -74,6 +74,10 @@ static void do_max_bank(enum eSectionType Type, int32_t nBank)
 		if (nBank > MaxVBankUsed)
 			MaxVBankUsed = nBank;
 		break;
+	case SECT_ROM0:
+	case SECT_WRAM0:
+	case SECT_OAM:
+	case SECT_HRAM:
 	default:
 		break;
 	}
@@ -317,8 +321,9 @@ struct sSection *GetSectionByName(const char *name)
 	return NULL;
 }
 
-int32_t IsSectionSameTypeBankAndFloating(const char *name,
-					 enum eSectionType type, int32_t bank)
+int32_t IsSectionSameTypeBankAndAttrs(const char *name,
+				      enum eSectionType type, int32_t bank,
+				      int32_t org, int32_t align)
 {
 	const struct sSection *pSection;
 
@@ -336,8 +341,9 @@ int32_t IsSectionSameTypeBankAndFloating(const char *name,
 		 * mismatch or not.
 		 */
 
-		/* Section must be floating in source */
-		if (pSection->nOrg != -1 || pSection->nAlign != 1)
+		/* Section must have the same attributes or float */
+		if ((pSection->nOrg != -1 && pSection->nOrg != org) ||
+		    (pSection->nAlign != 1 && pSection->nAlign != align))
 			return 0;
 
 		/* It must have the same type in source and linkerscript */
@@ -370,15 +376,6 @@ uint32_t AssignSectionAddressAndBankByName(const char *name, uint32_t address,
 
 		/* Section has been found. */
 
-		/*
-		 * A section can be left as floating in the code if the location
-		 * is assigned in the linkerscript.
-		 */
-		if (pSection->nOrg != -1 || pSection->nAlign != 1) {
-			errx(1, "Section \"%s\" from linkerscript isn't floating.\n",
-			     name);
-		}
-
 		/* The bank can be left as unassigned or be the same */
 		if (pSection->nBank != -1 && pSection->nBank != bank) {
 			errx(1, "Section \"%s\" from linkerscript has different bank number than in the source.\n",
@@ -494,7 +491,6 @@ void SetLinkerscriptName(char *tzLinkerscriptFile)
 
 void AssignSections(void)
 {
-	int32_t i;
 	struct sSection *pSection;
 
 	MaxBankUsed = 0;
@@ -503,7 +499,7 @@ void AssignSections(void)
 	 * Initialize the memory areas
 	 */
 
-	for (i = 0; i < BANK_INDEX_MAX; i += 1) {
+	for (int32_t i = 0; i < BANK_INDEX_MAX; i += 1) {
 		BankFree[i] = malloc(sizeof(*BankFree[i]));
 
 		if (!BankFree[i]) {
@@ -617,6 +613,9 @@ void AssignSections(void)
 				     pSection->nOrg, pSection->nBank);
 			}
 			break;
+		default:
+			errx(1, "%s: Internal error: Type %d", __func__,
+			     pSection->Type);
 		}
 	}
 
@@ -660,6 +659,10 @@ void AssignSections(void)
 			do_max_bank(pSection->Type, pSection->nBank);
 			break;
 
+		case SECT_ROM0:
+		case SECT_WRAM0:
+		case SECT_OAM:
+		case SECT_HRAM:
 		default: /* Handle other sections later */
 			break;
 		}

src/link/lexer.l

@@ -23,7 +23,7 @@
 
 #include "types.h"
 
-extern int yyparse();
+extern int yyparse(void);
 
 /* File include stack. */
 
@@ -179,13 +179,13 @@ void script_PrintFileStack(void)
 	fprintf(stderr, "%s(%d)", linkerscript_path, include_line[i]);
 }
 
-noreturn void script_fatalerror(const char *fmt, ...)
+noreturn_ void script_fatalerror(const char *fmt, ...)
 {
 	va_list args;
 	va_start(args, fmt);
 	fprintf(stderr, "error: ");
 	script_PrintFileStack();
-	fprintf(stderr, ":\n\t");
+	fprintf(stderr, ":\n    ");
 	vfprintf(stderr, fmt, args);
 	fprintf(stderr, "\n");
 	va_end(args);

src/link/mapfile.c

@@ -120,6 +120,10 @@ void MapfileWriteSection(const struct sSection *pSect)
 	for (i = 0; i < pSect->nNumberOfSymbols; i += 1) {
 		const struct sSymbol *pSym = pSect->tSymbols[i];
 
+		/* Don't print '@' */
+		if (strcmp(pSym->pzName, "@") == 0)
+			continue;
+
 		if ((pSym->pSection == pSect) && (pSym->Type != SYM_IMPORT)) {
 			if (mf) {
 				fprintf(mf, "           $%04X = %s\n",

src/link/object.c

@@ -28,7 +28,6 @@
 struct sSymbol **tSymbols;
 struct sSection *pSections;
 struct sSection *pLibSections;
-uint8_t dummymem;
 uint8_t oReadLib;
 
 /*
@@ -36,14 +35,14 @@ uint8_t oReadLib;
  */
 static int32_t readlong(FILE *f)
 {
-	int32_t r;
+	uint32_t r;
 
-	r = fgetc(f);
-	r |= fgetc(f) << 8;
-	r |= fgetc(f) << 16;
-	r |= fgetc(f) << 24;
+	r = ((uint32_t)(uint8_t)fgetc(f));
+	r |= ((uint32_t)(uint8_t)fgetc(f)) << 8;
+	r |= ((uint32_t)(uint8_t)fgetc(f)) << 16;
+	r |= ((uint32_t)(uint8_t)fgetc(f)) << 24;
 
-	return r;
+	return (int32_t)r;
 }
 
 /*
@@ -209,7 +208,7 @@ struct sSection *obj_ReadRGBSection(FILE *f)
 	if (pSection->nByteSize == 0) {
 		/* Skip number of patches */
 		readlong(f);
-		pSection->pData = &dummymem;
+		pSection->pData = NULL;
 		return pSection;
 	}
 
@@ -283,7 +282,7 @@ void obj_ReadRGB(FILE *pObjfile, char *tzObjectfile)
 		for (i = 0; i < nNumberOfSymbols; i += 1)
 			tSymbols[i] = obj_ReadSymbol(pObjfile, tzObjectfile);
 	} else {
-		tSymbols = (struct sSymbol **)&dummymem;
+		tSymbols = NULL;
 	}
 
 	/* Next we have the sections */

src/link/output.c

@@ -110,46 +110,53 @@ void Output(void)
 	FILE *f_overlay = NULL;
 
 	/*
-	 * Apply overlay
+	 * Load overlay
+	 */
+
+	if (tzOverlayname) {
+		f_overlay = fopen(tzOverlayname, "rb");
+
+		if (!f_overlay) {
+			errx(1, "Failed to open overlay file %s\n",
+			     tzOverlayname);
+		}
+
+		fseek(f_overlay, 0, SEEK_END);
+
+		if (ftell(f_overlay) % 0x4000 != 0)
+			errx(1, "Overlay file must be aligned to 0x4000 bytes.");
+
+		MaxOverlayBank = (ftell(f_overlay) / 0x4000) - 1;
+
+		if (MaxOverlayBank < 1)
+			errx(1, "Overlay file must be at least 0x8000 bytes.");
+
+		if (MaxOverlayBank > MaxBankUsed)
+			MaxBankUsed = MaxOverlayBank;
+	}
+
+	/*
+	 * Write ROM.
 	 */
 
 	f = fopen(tzOutname, "wb");
-
 	if (f != NULL) {
-		if (tzOverlayname) {
-			f_overlay = fopen(tzOverlayname, "rb");
-
-			if (!f_overlay) {
-				errx(1, "Failed to open overlay file %s\n",
-				     tzOverlayname);
-			}
-
-			fseek(f_overlay, 0, SEEK_END);
-
-			if (ftell(f_overlay) % 0x4000 != 0)
-				errx(1, "Overlay file must be aligned to 0x4000 bytes.");
-
-			MaxOverlayBank = (ftell(f_overlay) / 0x4000) - 1;
-
-			if (MaxOverlayBank < 1)
-				errx(1, "Overlay file must be at least 0x8000 bytes.");
-
-			if (MaxOverlayBank > MaxBankUsed)
-				MaxBankUsed = MaxOverlayBank;
-		}
-
 		writehome(f, f_overlay);
 		for (i = 1; i <= MaxBankUsed; i += 1)
 			writebank(f, f_overlay, i);
 
 		fclose(f);
-
-		if (tzOverlayname)
-			fclose(f_overlay);
 	}
 
 	/*
-	 * Add regular sections
+	 * Close overlay
+	 */
+
+	if (tzOverlayname)
+		fclose(f_overlay);
+
+	/*
+	 * Add regular sections to map and sym files.
 	 */
 
 	for (i = BANK_INDEX_WRAM0; i < BANK_INDEX_MAX; i++) {

src/link/parser.y

@@ -14,7 +14,7 @@
 
 #include "link/script.h"
 
-int yylex();
+int yylex(void);
 void yyerror(char *);
 
 extern int yylineno;
@@ -107,8 +107,8 @@ statement:
 
 %%
 
-extern int yylex();
-extern int yyparse();
+extern int yylex(void);
+extern int yyparse(void);
 
 int yywrap(void)
 {

src/link/patch.c

@@ -267,6 +267,7 @@ void Patch(void)
 		pPatch = pSect->pPatches;
 		while (pPatch) {
 			int32_t t;
+			int32_t nPatchOrg;
 
 			nPC = pSect->nOrg + pPatch->nOffset;
 			t = calcrpn(pPatch);
@@ -306,6 +307,26 @@ void Patch(void)
 				pSect->pData[pPatch->nOffset + 3] =
 					(t >> 24) & 0xFF;
 				break;
+			case PATCH_BYTE_JR:
+				/* Calculate absolute address of the patch */
+				nPatchOrg = pSect->nOrg + pPatch->nOffset;
+
+				/* t contains the destination of the jump */
+				t = (int16_t)((t & 0xFFFF) - (nPatchOrg + 1));
+
+				if (t >= -128 && t <= 127) {
+					t &= 0xFF;
+					pSect->pData[pPatch->nOffset] =
+						(uint8_t)t;
+				} else {
+					errx(1,
+					     "%s(%ld) : Value must be 8-bit",
+					     pPatch->pzFilename,
+					     pPatch->nLineNo);
+				}
+				break;
+			default:
+				errx(1, "%s: Internal error.", __func__);
 			}
 
 			pPatch = pPatch->pNext;

src/link/rgblink.1

@@ -57,7 +57,7 @@ Write a symbol file to the given filename.
 .It Fl O Ar overlayfile
 The ROM image to overlay sections over.
 When an overlay ROM is provided, all sections must be fixed.
-This may be used to patch an existing binray.
+This may be used to patch an existing binary.
 .It Fl o Ar outfile
 Write ROM image to the given filename.
 .It Fl p Ar pad_value

src/link/script.c

@@ -23,6 +23,10 @@ static struct {
 static int32_t current_bank = -1; /* Bank as seen by the bank array */
 static int32_t current_real_bank = -1; /* bank as seen by the GB */
 
+/* Current section attributes */
+static int32_t fix_org = -1;
+static int32_t fix_align = 1;
+
 void script_InitSections(void)
 {
 	int32_t i;
@@ -85,59 +89,59 @@ void script_InitSections(void)
 	}
 }
 
-void script_SetCurrentSectionType(const char *type, uint32_t bank)
+void script_SetCurrentSectionType(const char *type, uint32_t bank_num)
 {
 	if (strcmp(type, "ROM0") == 0) {
-		if (bank != 0)
+		if (bank_num != 0)
 			errx(1, "Trying to assign a bank number to ROM0.\n");
 		current_bank = BANK_INDEX_ROM0;
 		current_real_bank = 0;
 		return;
 	} else if (strcmp(type, "ROMX") == 0) {
-		if (bank == 0)
+		if (bank_num == 0)
 			errx(1, "ROMX index can't be 0.\n");
-		if (bank > BANK_COUNT_ROMX) {
-			errx(1, "ROMX index too big (%d > %d).\n", bank,
+		if (bank_num > BANK_COUNT_ROMX) {
+			errx(1, "ROMX index too big (%d > %d).\n", bank_num,
 			     BANK_COUNT_ROMX);
 		}
-		current_bank = BANK_INDEX_ROMX + bank - 1;
-		current_real_bank = bank;
+		current_bank = BANK_INDEX_ROMX + bank_num - 1;
+		current_real_bank = bank_num;
 		return;
 	} else if (strcmp(type, "VRAM") == 0) {
-		if (bank >= BANK_COUNT_VRAM) {
-			errx(1, "VRAM index too big (%d >= %d).\n", bank,
+		if (bank_num >= BANK_COUNT_VRAM) {
+			errx(1, "VRAM index too big (%d >= %d).\n", bank_num,
 			     BANK_COUNT_VRAM);
 		}
-		current_bank = BANK_INDEX_VRAM + bank;
-		current_real_bank = bank;
+		current_bank = BANK_INDEX_VRAM + bank_num;
+		current_real_bank = bank_num;
 		return;
 	} else if (strcmp(type, "WRAM0") == 0) {
-		if (bank != 0)
+		if (bank_num != 0)
 			errx(1, "Trying to assign a bank number to WRAM0.\n");
 
 		current_bank = BANK_INDEX_WRAM0;
 		current_real_bank = 0;
 		return;
 	} else if (strcmp(type, "WRAMX") == 0) {
-		if (bank == 0)
+		if (bank_num == 0)
 			errx(1, "WRAMX index can't be 0.\n");
-		if (bank > BANK_COUNT_WRAMX) {
-			errx(1, "WRAMX index too big (%d > %d).\n", bank,
+		if (bank_num > BANK_COUNT_WRAMX) {
+			errx(1, "WRAMX index too big (%d > %d).\n", bank_num,
 			     BANK_COUNT_WRAMX);
 		}
-		current_bank = BANK_INDEX_WRAMX + bank - 1;
-		current_real_bank = bank;
+		current_bank = BANK_INDEX_WRAMX + bank_num - 1;
+		current_real_bank = bank_num;
 		return;
 	} else if (strcmp(type, "SRAM") == 0) {
-		if (bank >= BANK_COUNT_SRAM) {
-			errx(1, "SRAM index too big (%d >= %d).\n", bank,
+		if (bank_num >= BANK_COUNT_SRAM) {
+			errx(1, "SRAM index too big (%d >= %d).\n", bank_num,
 			     BANK_COUNT_SRAM);
 		}
-		current_bank = BANK_INDEX_SRAM + bank;
-		current_real_bank = bank;
+		current_bank = BANK_INDEX_SRAM + bank_num;
+		current_real_bank = bank_num;
 		return;
 	} else if (strcmp(type, "OAM") == 0) {
-		if (bank != 0) {
+		if (bank_num != 0) {
 			errx(1, "%s: Trying to assign a bank number to OAM.\n",
 			     __func__);
 		}
@@ -145,7 +149,7 @@ void script_SetCurrentSectionType(const char *type, uint32_t bank)
 		current_real_bank = 0;
 		return;
 	} else if (strcmp(type, "HRAM") == 0) {
-		if (bank != 0) {
+		if (bank_num != 0) {
 			errx(1, "%s: Trying to assign a bank number to HRAM.\n",
 			     __func__);
 		}
@@ -176,6 +180,8 @@ void script_SetAddress(uint32_t addr)
 		     bank[current_bank].address,
 		     bank[current_bank].top_address);
 	}
+
+	fix_org = addr;
 }
 
 void script_SetAlignment(uint32_t alignment)
@@ -200,6 +206,8 @@ void script_SetAlignment(uint32_t alignment)
 		     bank[current_bank].address,
 		     bank[current_bank].top_address);
 	}
+
+	fix_align = size;
 }
 
 void script_OutputSection(const char *section_name)
@@ -209,9 +217,11 @@ void script_OutputSection(const char *section_name)
 		     section_name);
 	}
 
-	if (!IsSectionSameTypeBankAndFloating(section_name,
-					      bank[current_bank].type,
-					      current_real_bank)) {
+	if (!IsSectionSameTypeBankAndAttrs(section_name,
+					   bank[current_bank].type,
+					   current_real_bank,
+					   fix_org,
+					   fix_align)) {
 		errx(1, "Different attributes for \"%s\" in source and linkerscript\n",
 		     section_name);
 	}
@@ -221,5 +231,7 @@ void script_OutputSection(const char *section_name)
 		AssignSectionAddressAndBankByName(section_name,
 						  bank[current_bank].address,
 						  current_real_bank);
-}
 
+	fix_org = -1;
+	fix_align = 1;
+}

src/rgbds.5

@@ -57,7 +57,9 @@ REPT    NumberOfSymbols   ; Number of symbols defined in this object file.
         LONG    LineNum   ; Line number in the file where the symbol is defined.
 
         LONG    SectionID ; The section number (of this object file) in which
-                          ; this symbol is defined.
+                          ; this symbol is defined. If it doesn't belong to any
+                          ; specific section (like a constant), this field has
+                          ; the value -1.
 
         LONG    Value     ; The symbols value. It's the offset into that
                           ; symbol's section.
@@ -113,6 +115,7 @@ REPT NumberOfSections
             BYTE    Type         ; 0 = BYTE patch.
                                  ; 1 = little endian WORD patch.
                                  ; 2 = little endian LONG patch.
+                                 ; 3 = JR offset value BYTE patch.
 
             LONG    RPNSize      ; Size of the buffer with the RPN.
                                  ; expression.

src/rgbds.7

@@ -5,7 +5,7 @@
 .\"
 .\" SPDX-License-Identifier: MIT
 .\"
-.Dd January 26, 2018
+.Dd March 7, 2018
 .Dt RGBDS 7
 .Os RGBDS Manual
 .Sh NAME
@@ -14,9 +14,11 @@
 .Sh EXAMPLES
 To get a working ROM image from a single assembly source file:
 .Pp
-.D1 $ rgbasm \-o bar.o foo.asm
-.D1 $ rgblink \-o baz.gb bar.o
-.D1 $ rgbfix \-v \-p 0 baz.gb
+.Bd -literal -offset indent
+$ rgbasm \-o bar.o foo.asm
+$ rgblink \-o baz.gb bar.o
+$ rgbfix \-v \-p 0 baz.gb
+.Ed
 .Sh SEE ALSO
 .Xr rgbasm 1 ,
 .Xr rgbfix 1 ,
@@ -41,5 +43,6 @@ implementation of rgbds.
 2017, Bentley's repository is moved to a neutral name.
 It is now maintained by a number of contributors at
 .Lk https://github.com/rednex/rgbds .
+.It
 2018, codebase relicensed under the MIT license.
 .El

test/asm/divzero-instr.out

@@ -1,2 +1,2 @@
 ERROR: divzero-instr.asm(2):
-	division by zero
+    Division by zero

test/asm/divzero-section-bank.out

@@ -1,2 +1,4 @@
 ERROR: divzero-section-bank.asm(1):
-	division by zero
+    Invalid integer constant
+ERROR: divzero-section-bank.asm(1):
+    Division by zero

test/asm/equ-charmap.asm

@@ -0,0 +1,4 @@
+SECTION "sec", ROM0
+	charmap "A", 1
+_A_ EQU "A"
+	db _A_

test/asm/equ-charmap.out.bin

@@ -0,0 +1 @@
+

test/asm/label-redefinition.asm

@@ -0,0 +1,7 @@
+SECTION "sec", ROM0
+    dw Sym
+m: MACRO
+Sym::
+ENDM
+    m
+Sym::

test/asm/label-redefinition.out

@@ -0,0 +1,3 @@
+ERROR: label-redefinition.asm(7):
+    'Sym' already defined in m(6)
+error: Assembly aborted in pass 1 (1 errors)!

test/asm/line-continuation.asm

@@ -0,0 +1 @@
+foo @bar\

test/asm/line-continuation.out

@@ -0,0 +1,2 @@
+ERROR: line-continuation.asm(2) -> @(-1):
+    Macro '@' not defined

test/asm/local-wrong-parent.out

@@ -1,3 +1,3 @@
 ERROR: local-wrong-parent.asm(5):
-	Not currently in the scope of 'WrongParent'
+    Not currently in the scope of 'WrongParent'
 error: Assembly aborted in pass 1 (1 errors)!

test/asm/macro-@.out

@@ -1,2 +1,2 @@
 ERROR: macro-@.asm(1) -> @(-1):
-	Macro '@' not defined
+    Macro '@' not defined

test/asm/null-in-macro.out

@@ -1,2 +1,2 @@
 ERROR: null-in-macro.asm(1):
-	Unterminated MACRO definition.
+    Unterminated MACRO definition.

test/asm/remote-local-noexist.out

@@ -1,2 +1,2 @@
 ERROR: remote-local-noexist.asm(7):
-	'Parent.child.fail' is a nonsensical reference to a nested local symbol
+    'Parent.child.fail' is a nonsensical reference to a nested local symbol

test/asm/test.sh

@@ -1,11 +1,24 @@
 #!/bin/sh
-fname=$(mktemp)
+o=$(mktemp)
+gb=$(mktemp)
+before=$(mktemp)
+after=$(mktemp)
 rc=0
 
 for i in *.asm; do
-	../../rgbasm $i >$fname 2>&1
-	diff -u $fname ${i%.asm}.out
+	../../rgbasm -o $o $i > $after 2>&1
+	diff -u ${i%.asm}.out $after
 	rc=$(($? || $rc))
+	bin=${i%.asm}.out.bin
+	if [ -f $bin ]; then
+		../../rgblink -o $gb $o > $after 2>&1
+		head -c $(wc -c < $bin) $gb > $after 2>&1
+		hexdump -C $after > $before && mv $before $after
+		hexdump -C $bin > $before
+		diff -u $before $after
+		rc=$(($? || $rc))
+	fi
 done
 
+rm -f $o $gb $before $after
 exit $rc

test/asm/undefined-dot.out

@@ -1,3 +1,3 @@
 ERROR: undefined-dot.asm(3):
-	'.' not defined
+    '.' not defined
 error: Assembly aborted in pass 2 (1 errors)!

test/asm/update-refs.sh

@@ -6,4 +6,5 @@ for i in *.asm; do
 	mv -f $fname ${i%.asm}.out
 done
 
+rm -f $fname
 exit 0

test/asm/utf-8.asm

@@ -0,0 +1,2 @@
+SECTION "sec", ROM0
+	db "é"

test/asm/utf-8.out.bin

@@ -0,0 +1 @@
+é

test/link/section-attributes-mismatch.link

@@ -0,0 +1,5 @@
+ROM0
+	org $10
+	"sec"
+	org $20
+	"secfix"

test/link/section-attributes-mismatch.out

@@ -0,0 +1,2 @@
+error: Different attributes for "sec" in source and linkerscript
+

test/link/section-attributes.asm

@@ -0,0 +1,2 @@
+SECTION "sec",ROM0,ALIGN[4]
+SECTION "secfix",ROM0[$20]

test/link/section-attributes.link

@@ -0,0 +1,5 @@
+ROM0
+	align 4
+	"sec"
+	org $20
+	"secfix"

test/link/test.sh

@@ -16,6 +16,14 @@ head -c 20 $gbtemp > $otemp 2>&1
 diff bank-numbers.out.bin $otemp
 rc=$(($? || $rc))
 
+$RGBASM -o $otemp section-attributes.asm
+$RGBLINK -l section-attributes.link -o $gbtemp $otemp > $outtemp 2>&1
+diff section-attributes.out $outtemp
+rc=$(($? || $rc))
+$RGBLINK -l section-attributes-mismatch.link -o $gbtemp $otemp > $outtemp 2>&1
+diff section-attributes-mismatch.out $outtemp
+rc=$(($? || $rc))
+
 $RGBASM -o $otemp wramx-dmg-mode.asm
 $RGBLINK -o $gbtemp $otemp > $outtemp 2>&1
 diff wramx-dmg-mode-no-d.out $outtemp
@@ -60,4 +68,5 @@ $RGBLINK -o $gbtemp $otemp
 diff all-instructions.out.bin $gbtemp
 rc=$(($? || $rc))
 
+rm -f $otemp $gbtemp $gbtemp2 $outtemp
 exit $rc

test/link/update-refs.sh

@@ -9,6 +9,12 @@ $RGBASM -o $otemp bank-numbers.asm
 $RGBLINK -o $gbtemp $otemp > bank-numbers.out 2>&1
 head -c 20 $gbtemp > bank-numbers.out.bin 2>&1
 
+$RGBASM -o $otemp section-attributes.asm
+$RGBLINK -l section-attributes.link \
+	-o $gbtemp $otemp > section-attributes.out 2>&1
+$RGBLINK -l section-attributes-mismatch.link \
+	-o $gbtemp $otemp > section-attributes-mismatch.out 2>&1
+
 $RGBASM -o $otemp wramx-dmg-mode.asm
 $RGBLINK -o $gbtemp $otemp > wramx-dmg-mode-no-d.out 2>&1
 $RGBLINK -d -o $gbtemp $otemp > wramx-dmg-mode-d.out 2>&1
@@ -28,4 +34,5 @@ $RGBLINK -t -o $gbtemp $otemp > romx-tiny-t.out 2>&1
 $RGBASM -o $otemp all-instructions.asm
 $RGBLINK -o all-instructions.out.bin $otemp 2>&1
 
+rm -f $otemp $gbtemp
 exit 0

test/run-tests.sh

@@ -15,20 +15,33 @@ pushd link
 popd
 
 # Test some significant external projects that use RGBDS
+# When adding new ones, don't forget to add them to the .gitignore!
 
-git clone https://github.com/pret/pokecrystal.git --depth=1
+if [ ! -d pokecrystal ]; then
+	git clone https://github.com/pret/pokecrystal.git --shallow-since=2018-06-04 --single-branch
+fi
 pushd pokecrystal
+git fetch
+git checkout 06e169d
 make -j
 make compare
 popd
 
-git clone --recursive https://github.com/pret/pokered.git --depth=1
+if [ ! -d pokered ]; then
+	git clone --recursive https://github.com/pret/pokered.git --shallow-since=2018-03-23 --single-branch
+fi
 pushd pokered
+git fetch
+git checkout 98f09b6
 make -j
 make compare
 popd
 
-git clone https://github.com/AntonioND/ucity.git --depth=1
+if [ ! -d ucity ]; then
+	git clone https://github.com/AntonioND/ucity.git --shallow-since=2017-07-13 --single-branch
+fi
 pushd ucity
+git fetch
+git checkout 3315601
 make -j
 popd