Improve error messages

Signed-off-by: Antonio Niño Díaz <antonio_nd@outlook.com>

GNUmakefile

@@ -1,6 +0,0 @@
-# GNU Make 3.x doesn't support the "!=" shell syntax, so here's an alternative
-
-PKG_CONFIG = pkg-config
-PNGFLAGS = $(shell ${PKG_CONFIG} --cflags libpng)
-
-include Makefile

Makefile

@@ -1,25 +1,42 @@
-PKG_CONFIG	= pkg-config
-WARNFLAGS	= -Wall -Werror
-PNGFLAGS	!= ${PKG_CONFIG} --cflags libpng
-REALCFLAGS	= ${CFLAGS} ${WARNFLAGS} ${PNGFLAGS} -Iinclude -g \
-		-std=c99 -D_POSIX_C_SOURCE=200809L
+# User-defined variables
 
+Q		:= @
+PREFIX		:= /usr/local
+bindir		:= ${PREFIX}/bin
+mandir		:= ${PREFIX}/man
+STRIP		:= -s
+BINMODE		:= 555
+MANMODE		:= 444
+
+# Other variables
+
+PKG_CONFIG	:= pkg-config
+PNGCFLAGS	:= `${PKG_CONFIG} --static --cflags libpng`
+PNGLDFLAGS	:= `${PKG_CONFIG} --static --libs-only-L libpng`
+PNGLDLIBS	:= `${PKG_CONFIG} --static --libs-only-l libpng`
+
+VERSION_STRING	:= `git describe --tags --dirty --always 2>/dev/null`
+
+WARNFLAGS	:= -Wall -Werror
+
+# Overridable CFLAGS
+CFLAGS		:= -g
+# Non-overridable CFLAGS
+REALCFLAGS	:= ${CFLAGS} ${WARNFLAGS} -std=c99 -D_POSIX_C_SOURCE=200809L \
+		   -Iinclude -DBUILD_VERSION_STRING=\"${VERSION_STRING}\"
+
+YFLAGS		:=
 LFLAGS		:= --nounistd
 
 YACC		:= yacc
-FLEX		:= flex
+LEX		:= flex
 RM		:= rm -rf
 
-# User-defined variables
-PREFIX		= /usr/local
-bindir		= ${PREFIX}/bin
-mandir		= ${PREFIX}/man
-Q		= @
-STRIP		= -s
-BINMODE		= 555
-MANMODE		= 444
+# Rules to build the RGBDS binaries
 
-rgbasm_obj = \
+all: rgbasm rgblink rgbfix rgbgfx
+
+rgbasm_obj := \
 	src/asm/asmy.o \
 	src/asm/charmap.o \
 	src/asm/fstack.o \
@@ -34,9 +51,14 @@ rgbasm_obj = \
 	src/extern/err.o \
 	src/extern/reallocarray.o \
 	src/extern/strlcpy.o \
-	src/extern/strlcat.o
+	src/extern/strlcat.o \
+	src/extern/version.o
 
-rgblink_obj = \
+
+src/asm/asmy.h: src/asm/asmy.c
+src/asm/locallex.o src/asm/globlex.o src/asm/lexer.o: src/asm/asmy.h
+
+rgblink_obj := \
 	src/link/assign.o \
 	src/link/lexer.o \
 	src/link/library.o \
@@ -48,45 +70,23 @@ rgblink_obj = \
 	src/link/parser.o \
 	src/link/script.o \
 	src/link/symbol.o \
-	src/extern/err.o
+	src/extern/err.o \
+	src/extern/version.o
 
-rgbfix_obj = \
+src/link/parser.h: src/link/parser.c
+src/link/lexer.o: src/link/parser.h
+
+rgbfix_obj := \
 	src/fix/main.o \
-	src/extern/err.o
+	src/extern/err.o \
+	src/extern/version.o
 
-rgbgfx_obj = \
+rgbgfx_obj := \
 	src/gfx/gb.o \
 	src/gfx/main.o \
 	src/gfx/makepng.o \
-	src/extern/err.o
-
-all: rgbasm rgblink rgbfix rgbgfx
-
-clean:
-	$Q${RM} rgbds.7.html gbz80.7.html rgbds.5.html
-	$Q${RM} rgbasm rgbasm.exe ${rgbasm_obj} rgbasm.1.html rgbasm.5.html
-	$Q${RM} rgblink rgblink.exe ${rgblink_obj} rgblink.1.html rgblink.5.html
-	$Q${RM} rgbfix rgbfix.exe ${rgbfix_obj} rgbfix.1.html
-	$Q${RM} rgbgfx rgbgfx.exe ${rgbgfx_obj} rgbgfx.1.html
-	$Q${RM} src/asm/asmy.c src/asm/asmy.h
-	$Q${RM} src/link/lexer.c src/link/parser.c src/link/parser.h
-
-install: all
-	$Qmkdir -p ${DESTDIR}${bindir}
-	$Qinstall ${STRIP} -m ${BINMODE} rgbasm ${DESTDIR}${bindir}/rgbasm
-	$Qinstall ${STRIP} -m ${BINMODE} rgbfix ${DESTDIR}${bindir}/rgbfix
-	$Qinstall ${STRIP} -m ${BINMODE} rgblink ${DESTDIR}${bindir}/rgblink
-	$Qinstall ${STRIP} -m ${BINMODE} rgbgfx ${DESTDIR}${bindir}/rgbgfx
-	$Qmkdir -p ${DESTDIR}${mandir}/man1 ${DESTDIR}${mandir}/man5 ${DESTDIR}${mandir}/man7
-	$Qinstall -m ${MANMODE} src/rgbds.7 ${DESTDIR}${mandir}/man7/rgbds.7
-	$Qinstall -m ${MANMODE} src/gbz80.7 ${DESTDIR}${mandir}/man7/gbz80.7
-	$Qinstall -m ${MANMODE} src/rgbds.5 ${DESTDIR}${mandir}/man7/rgbds.5
-	$Qinstall -m ${MANMODE} src/asm/rgbasm.1 ${DESTDIR}${mandir}/man1/rgbasm.1
-	$Qinstall -m ${MANMODE} src/asm/rgbasm.5 ${DESTDIR}${mandir}/man1/rgbasm.5
-	$Qinstall -m ${MANMODE} src/fix/rgbfix.1 ${DESTDIR}${mandir}/man1/rgbfix.1
-	$Qinstall -m ${MANMODE} src/link/rgblink.1 ${DESTDIR}${mandir}/man1/rgblink.1
-	$Qinstall -m ${MANMODE} src/link/rgblink.5 ${DESTDIR}${mandir}/man5/rgblink.5
-	$Qinstall -m ${MANMODE} src/gfx/rgbgfx.1 ${DESTDIR}${mandir}/man1/rgbgfx.1
+	src/extern/err.o \
+	src/extern/version.o
 
 rgbasm: ${rgbasm_obj}
 	$Q${CC} ${REALCFLAGS} -o $@ ${rgbasm_obj} -lm
@@ -98,52 +98,56 @@ rgbfix: ${rgbfix_obj}
 	$Q${CC} ${REALCFLAGS} -o $@ ${rgbfix_obj}
 
 rgbgfx: ${rgbgfx_obj}
-	$Q${CC} ${REALCFLAGS} -o $@ ${rgbgfx_obj} `${PKG_CONFIG} --libs libpng`
+	$Q${CC} ${REALCFLAGS} ${PNGLDFLAGS} -o $@ ${rgbgfx_obj} ${PNGLDLIBS}
+
+# Rules to process files
 
 .y.c:
 	$Q${YACC} -d ${YFLAGS} -o $@ $<
 
 .l.o:
 	$Q${RM} $*.c
-	$Q${FLEX} ${LFLAGS} -o $*.c $<
+	$Q${LEX} ${LFLAGS} -o $*.c $<
 	$Q${CC} ${REALCFLAGS} -c -o $@ $*.c
 	$Q${RM} $*.c
 
 .c.o:
-	$Q${CC} ${REALCFLAGS} -c -o $@ $<
+	$Q${CC} ${REALCFLAGS} ${PNGCFLAGS} -c -o $@ $<
 
-src/asm/locallex.o src/asm/globlex.o src/asm/lexer.o: src/asm/asmy.h
-src/asm/asmy.h: src/asm/asmy.c
+# Target used to remove all files generated by other Makefile targets.
 
-src/link/lexer.o : src/link/parser.h
-src/link/parser.h : src/link/parser.c
+clean:
+	$Q${RM} rgbds.7.html gbz80.7.html rgbds.5.html
+	$Q${RM} rgbasm rgbasm.exe ${rgbasm_obj} rgbasm.1.html rgbasm.5.html
+	$Q${RM} rgblink rgblink.exe ${rgblink_obj} rgblink.1.html rgblink.5.html
+	$Q${RM} rgbfix rgbfix.exe ${rgbfix_obj} rgbfix.1.html
+	$Q${RM} rgbgfx rgbgfx.exe ${rgbgfx_obj} rgbgfx.1.html
+	$Q${RM} src/asm/asmy.c src/asm/asmy.h
+	$Q${RM} src/link/lexer.c src/link/parser.c src/link/parser.h
 
-# Below is a target for the project maintainer to easily create win32 exes.
-# This is not for Windows users!
-# If you're building on Windows with Cygwin or Mingw, just follow the Unix
-# install instructions instead.
-mingw:
-	$Q${RM} win32 win64
-	$Qmkdir win32 win64
-	$Qenv make clean
-	$Qenv PKG_CONFIG_PATH=/usr/i686-w64-mingw32/sys-root/mingw/lib/pkgconfig/ \
-		make CC=i686-w64-mingw32-gcc YACC=bison WARNFLAGS= -j
-	$Qmv rgbasm win32/rgbasm.exe
-	$Qmv rgblink win32/rgblink.exe
-	$Qmv rgbfix win32/rgbfix.exe
-	$Qmv rgbgfx win32/rgbgfx.exe
-	$Qenv make clean
-	$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
-	$Qmv rgbasm win64/rgbasm.exe
-	$Qmv rgblink win64/rgblink.exe
-	$Qmv rgbfix win64/rgbfix.exe
-	$Qmv rgbgfx win64/rgbgfx.exe
-	$Qenv make clean
+# Target used to install the binaries and man pages.
 
-# Below is a target for the project maintainer to easily create web manuals.
+install: all
+	$Qmkdir -p ${DESTDIR}${bindir}
+	$Qinstall ${STRIP} -m ${BINMODE} rgbasm ${DESTDIR}${bindir}/rgbasm
+	$Qinstall ${STRIP} -m ${BINMODE} rgbfix ${DESTDIR}${bindir}/rgbfix
+	$Qinstall ${STRIP} -m ${BINMODE} rgblink ${DESTDIR}${bindir}/rgblink
+	$Qinstall ${STRIP} -m ${BINMODE} rgbgfx ${DESTDIR}${bindir}/rgbgfx
+	$Qmkdir -p ${DESTDIR}${mandir}/man1 ${DESTDIR}${mandir}/man5 ${DESTDIR}${mandir}/man7
+	$Qinstall -m ${MANMODE} src/rgbds.7 ${DESTDIR}${mandir}/man7/rgbds.7
+	$Qinstall -m ${MANMODE} src/gbz80.7 ${DESTDIR}${mandir}/man7/gbz80.7
+	$Qinstall -m ${MANMODE} src/rgbds.5 ${DESTDIR}${mandir}/man5/rgbds.5
+	$Qinstall -m ${MANMODE} src/asm/rgbasm.1 ${DESTDIR}${mandir}/man1/rgbasm.1
+	$Qinstall -m ${MANMODE} src/asm/rgbasm.5 ${DESTDIR}${mandir}/man5/rgbasm.5
+	$Qinstall -m ${MANMODE} src/fix/rgbfix.1 ${DESTDIR}${mandir}/man1/rgbfix.1
+	$Qinstall -m ${MANMODE} src/link/rgblink.1 ${DESTDIR}${mandir}/man1/rgblink.1
+	$Qinstall -m ${MANMODE} src/link/rgblink.5 ${DESTDIR}${mandir}/man5/rgblink.5
+	$Qinstall -m ${MANMODE} src/gfx/rgbgfx.1 ${DESTDIR}${mandir}/man1/rgbgfx.1
+
+# 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=manual.css
 
 wwwman:
 	$Qmandoc ${MANDOC} src/rgbds.7 > rgbds.7.html
@@ -155,3 +159,24 @@ wwwman:
 	$Qmandoc ${MANDOC} src/link/rgblink.1 > rgblink.1.html
 	$Qmandoc ${MANDOC} src/link/rgblink.5 > rgblink.5.html
 	$Qmandoc ${MANDOC} src/gfx/rgbgfx.1 > rgbgfx.1.html
+
+# 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
+# install instructions instead.
+
+mingw32:
+	$Qenv PKG_CONFIG_PATH=/usr/i686-w64-mingw32/sys-root/mingw/lib/pkgconfig/ \
+		make CC=i686-w64-mingw32-gcc YACC=bison WARNFLAGS= -j
+	$Qmv rgbasm rgbasm.exe
+	$Qmv rgblink rgblink.exe
+	$Qmv rgbfix rgbfix.exe
+	$Qmv rgbgfx rgbgfx.exe
+
+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
+	$Qmv rgbasm rgbasm.exe
+	$Qmv rgblink rgblink.exe
+	$Qmv rgbfix rgbfix.exe
+	$Qmv rgbgfx rgbgfx.exe

README.md

@@ -110,7 +110,6 @@ make command line. For example, to install RGBDS in your home directory instead
 of systemwide, run the following:
 
 ```sh
-mkdir -p $HOME/{bin,man/man1,man/man7}
 make install PREFIX=$HOME
 ```
 

include/asm/asm.h

@@ -18,18 +18,23 @@
 
 #include "asm/localasm.h"
 
+#define MAXUNIONS		128
+#define MAXMACROARGS	256
+#define MAXINCPATHS		128
+
 extern SLONG nLineNo;
 extern ULONG nTotalLines;
 extern ULONG nPC;
 extern ULONG nPass;
 extern ULONG nIFDepth;
+extern bool skipElif;
+extern ULONG nUnionDepth;
+extern ULONG unionStart[MAXUNIONS];
+extern ULONG unionSize[MAXUNIONS];
 extern char tzCurrentFileName[_MAX_PATH + 1];
 extern struct Section *pCurrentSection;
 extern struct sSymbol *tHashedSymbols[HASHSIZE];
 extern struct sSymbol *pPCSymbol;
 extern bool oDontExpandStrings;
 
-#define MAXMACROARGS	256
-#define MAXINCPATHS		128
-
 #endif	/* //       ASM_H */

include/asm/fstack.h

@@ -41,6 +41,8 @@ extern void fstk_RunRept(ULONG count);
 FILE *
 fstk_FindFile(char *);
 
+int fstk_GetLine(void);
+
 extern int yywrap(void);
 
 #endif

include/asm/localasm.h

@@ -80,8 +80,6 @@
 
  */
 
-#define MAXSECTIONSIZE	0x4000
-
 #define	NAME_DB			"db"
 #define	NAME_DW			"dw"
 #define	NAME_RB			"rb"

include/asm/main.h

@@ -26,8 +26,25 @@ extern void opt_Push(void);
 extern void opt_Pop(void);
 extern void opt_Parse(char *s);
 
+/*
+ * Used for errors that compromise the whole assembly process by affecting the
+ * folliwing code, potencially making the assembler generate errors caused by
+ * the first one and unrelated to the code that the assembler complains about.
+ * 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, ...);
+/*
+ * Used for errors that make it impossible to assemble correctly, but don't
+ * affect the following code. The code will fail to assemble but the user will
+ * get a list of all errors at the end, making it easier to fix all of them at
+ * once.
+ */
 void yyerror(const char *fmt, ...);
+/*
+ * Used to warn the user about problems that don't prevent the generation of
+ * valid code.
+ */
 void warning(const char *fmt, ...);
 
 #define	YY_FATAL_ERROR fatalerror

include/asm/symbol.h

@@ -16,6 +16,8 @@ struct sSymbol {
 	ULONG ulMacroSize;
 	char *pMacro;
 	SLONG(*Callback) (struct sSymbol *);
+	char tzFileName[_MAX_PATH + 1]; /* File where the symbol was defined. */
+	ULONG nFileLine; /* Line where the symbol was defined. */
 };
 #define SYMF_RELOC		0x001	/* symbol will be reloc'ed during
 					 * linking, it's absolute value is

include/common.h

@@ -0,0 +1,6 @@
+#ifndef RGBDS_COMMON_H
+#define RGBDS_COMMON_H
+
+#define RGBDS_OBJECT_VERSION_STRING "RGB5"
+
+#endif /* RGBDS_COMMON_H */

include/extern/version.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2017 Antonio Nino Diaz <antonio_nd@outlook.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#define PACKAGE_VERSION_MAJOR (0)
+#define PACKAGE_VERSION_MINOR (3)
+#define PACKAGE_VERSION_PATCH (2)
+
+const char * get_package_version_string(void);

include/link/mylink.h

@@ -89,6 +89,9 @@ struct sSymbol {
 	SLONG nSectionID;	/* internal to object.c */
 	struct sSection *pSection;
 	SLONG nOffset;
+	char *pzObjFileName; /* Object file where the symbol is located. */
+	char *pzFileName; /* Source file where the symbol was defined. */
+	ULONG nFileLine; /* Line where the symbol was defined. */
 };
 
 enum ePatchType {

include/link/symbol.h

@@ -4,7 +4,8 @@
 #include "types.h"
 
 void sym_Init(void);
-void sym_CreateSymbol(char *tzName, SLONG nValue, SLONG nBank);
+void sym_CreateSymbol(char *tzName, SLONG nValue, SLONG nBank,
+			char *tzObjFileName, char *tzFileName, ULONG nFileLine);
 SLONG sym_GetValue(char *tzName);
 SLONG sym_GetBank(char *tzName);
 

src/asm/asmy.y

@@ -23,7 +23,7 @@ ULONG	ulNewMacroSize;
 void
 bankrangecheck(char *name, ULONG secttype, SLONG org, SLONG bank)
 {
-	SLONG minbank, maxbank;
+	SLONG minbank = 0, maxbank = 0;
 	char *stype = NULL;
 	switch (secttype) {
 	case SECT_ROMX:
@@ -289,70 +289,75 @@ void	copymacro( void )
 	yyskipbytes( ulNewMacroSize+4 );
 }
 
-ULONG	isIf( char *s )
+ULONG	isIf(char *s)
 {
-	return( (strncasecmp(s,"If",2)==0) && isWhiteSpace(*(s-1)) && isWhiteSpace(s[2]) );
+	return((strncasecmp(s,"If",2) == 0) && isWhiteSpace(s[-1]) && isWhiteSpace(s[2]));
 }
 
-ULONG	isElse( char *s )
+ULONG	isElif(char *s)
 {
-	return( (strncasecmp(s,"Else",4)==0) && isWhiteSpace(*(s-1)) && isWhiteSpace(s[4]) );
+	return((strncasecmp(s,"Elif",4) == 0) && isWhiteSpace(s[-1]) && isWhiteSpace(s[4]));
 }
 
-ULONG	isEndc( char *s )
+ULONG	isElse(char *s)
 {
-	return( (strncasecmp(s,"Endc",4)==0) && isWhiteSpace(*(s-1)) && isWhiteSpace(s[4]) );
+	return((strncasecmp(s,"Else",4) == 0) && isWhiteSpace(s[-1]) && isWhiteSpace(s[4]));
 }
 
-void	if_skip_to_else( void )
+ULONG	isEndc(char *s)
 {
-	SLONG	level=1, len, instring=0;
+	return((strncasecmp(s,"Endc",4) == 0) && isWhiteSpace(s[-1]) && isWhiteSpace(s[4]));
+}
+
+void	if_skip_to_else()
+{
+	SLONG level = 1;
+	bool inString = false;
 	char *src=pCurrentBuffer->pBuffer;
 
-	while( *src && level )
-	{
-		if( *src=='\n' )
-			nLineNo+=1;
+	while (*src && level) {
+		if (*src == '\n') {
+			nLineNo++;
+		}
 
-		if( instring==0 )
-		{
-			if( isIf(src) )
-			{
-				level+=1;
-				src+=2;
+		if (!inString) {
+			if (isIf(src)) {
+				level++;
+				src += 2;
+
+			} else if (level == 1 && isElif(src)) {
+				level--;
+				skipElif = false;
+
+			} else if (level == 1 && isElse(src)) {
+				level--;
+				src += 4;
+
+			} else if (isEndc(src)) {
+				level--;
+				if (level != 0) {
+					src += 4;
 				}
-			else if( level==1 && isElse(src) )
-			{
-				level-=1;
-				src+=4;
+
+			} else {
+				if (*src=='\"') {
+					inString = true;
 				}
-			else if( isEndc(src) )
-			{
-				level-=1;
-				if( level!=0 )
-					src+=4;
+				src++;
 			}
-			else
-			{
-				if( *src=='\"' )
-					instring=1;
-				src+=1;
-			}
-		}
-		else
-		{
-			if( *src=='\\' )
-			{
-				src+=2;
-			}
-			else if( *src=='\"' )
-			{
-				src+=1;
-				instring=0;
-			}
-			else
-			{
-				src+=1;
+		} else {
+			switch (*src) {
+			case '\\':
+				src += 2;
+				break;
+
+			case '\"':
+				src++;
+				inString = false;
+
+			default:
+				src++;
+				break;
 			}
 		}
 	}
@@ -361,57 +366,56 @@ void	if_skip_to_else( void )
 		fatalerror("Unterminated IF construct");
 	}
 
-	len=src-pCurrentBuffer->pBuffer;
+	SLONG len = src - pCurrentBuffer->pBuffer;
 
-	yyskipbytes( len );
-	yyunput( '\n' );
-	nLineNo-=1;
+	yyskipbytes(len);
+	yyunput('\n');
+	nLineNo--;
 }
 
-void	if_skip_to_endc( void )
+void	if_skip_to_endc()
 {
-	SLONG	level=1, len, instring=0;
+	SLONG level = 1;
+	bool inString = false;
 	char *src=pCurrentBuffer->pBuffer;
 
-	while( *src && level )
-	{
-		if( *src=='\n' )
-			nLineNo+=1;
+	while (*src && level) {
+		if (*src == '\n') {
+			nLineNo++;
+		}
 
-		if( instring==0 )
-		{
-			if( isIf(src) )
-			{
-				level+=1;
-				src+=2;
+		if (!inString) {
+			if (isIf(src)) {
+				level++;
+				src += 2;
+
+			} else if (isEndc(src)) {
+				level--;
+				if (level != 0) {
+					src += 4;
 				}
-			else if( isEndc(src) )
-			{
-				level-=1;
-				if( level!=0 )
-					src+=4;
+
+			} else {
+				if (*src=='\"') {
+					inString = true;
 				}
-			else
-			{
-				if( *src=='\"' )
-					instring=1;
-				src+=1;
+				src++;
 			}
 		}
-		else
-		{
-			if( *src=='\\' )
-			{
-				src+=2;
-			}
-			else if( *src=='\"' )
-			{
-				src+=1;
-				instring=0;
-			}
-			else
-			{
-				src+=1;
+		else {
+			switch (*src) {
+			case '\\':
+				src += 2;
+				break;
+
+			case '\"':
+				src++;
+				inString = false;
+				break;
+
+			default:
+				src++;
+				break;
 			}
 		}
 	}
@@ -420,11 +424,39 @@ void	if_skip_to_endc( void )
 		fatalerror("Unterminated IF construct");
 	}
 
-	len=src-pCurrentBuffer->pBuffer;
+	SLONG len = src - pCurrentBuffer->pBuffer;
 
-	yyskipbytes( len );
-	yyunput( '\n' );
-	nLineNo-=1;
+	yyskipbytes(len);
+	yyunput('\n');
+	nLineNo--;
+}
+
+void startUnion() {
+	if (!pCurrentSection) {
+		fatalerror("UNIONs must be inside a SECTION");
+	}
+	
+	ULONG unionIndex = nUnionDepth;
+	nUnionDepth++;
+	if (nUnionDepth > MAXUNIONS) {
+		fatalerror("Too many nested UNIONs");
+	}
+	
+	unionStart[unionIndex] = nPC;
+	unionSize[unionIndex] = 0;
+}
+
+void updateUnion() {
+	ULONG unionIndex = nUnionDepth - 1;
+	ULONG size = nPC - unionStart[unionIndex];
+	
+	if (size > unionSize[unionIndex]) {
+		unionSize[unionIndex] = size;
+	}
+	
+	nPC = unionStart[unionIndex];
+	pCurrentSection->nPC = unionStart[unionIndex];
+	pPCSymbol->nValue = unionStart[unionIndex];
 }
 
 %}
@@ -439,6 +471,7 @@ void	if_skip_to_endc( void )
 
 %type	<sVal>	relocconst
 %type	<nConstValue>	const
+%type	<nConstValue>	uconst
 %type	<nConstValue>	const_3bit
 %type	<sVal>	const_8bit
 %type	<sVal>	const_16bit
@@ -491,7 +524,7 @@ void	if_skip_to_endc( void )
 %token	<tzSym> T_POP_SET
 %token	<tzSym> T_POP_EQUS
 
-%token	T_POP_INCLUDE T_POP_PRINTF T_POP_PRINTT T_POP_PRINTV T_POP_IF T_POP_ELSE T_POP_ENDC
+%token	T_POP_INCLUDE T_POP_PRINTF T_POP_PRINTT T_POP_PRINTV 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
 %token	T_POP_SECTION
@@ -501,6 +534,7 @@ void	if_skip_to_endc( void )
 %token	T_POP_MACRO
 %token	T_POP_ENDM
 %token	T_POP_RSRESET T_POP_RSSET
+%token	T_POP_UNION T_POP_NEXTU T_POP_ENDU
 %token	T_POP_INCBIN T_POP_REPT
 %token	T_POP_CHARMAP
 %token	T_POP_SHIFT
@@ -587,7 +621,11 @@ label : /* empty */
 		else
 			sym_AddReloc($1);
 	} | T_LABEL ':' ':' {
+		if ($1[0] == '.') {
+			sym_AddLocalReloc($1);
+		} else {
 			sym_AddReloc($1);
+		}
 		sym_Export($1);
 	};
 
@@ -622,6 +660,7 @@ simple_pseudoop	:	include
 				|	printt
 				|	printv
 				|	if
+				|	elif
 				|	else
 				|	endc
 				|	import
@@ -634,6 +673,9 @@ simple_pseudoop	:	include
 				|	section
 				|	rsreset
 				|	rsset
+				|	union
+				|	nextu
+				|	endu
 				|	incbin
 				|	charmap
 				|	rept
@@ -688,7 +730,7 @@ shift			:	T_POP_SHIFT
 					{ sym_ShiftCurrentMacroArgs(); }
 ;
 
-rept			:	T_POP_REPT const
+rept			:	T_POP_REPT uconst
 					{
 						copyrept();
 						fstk_RunRept( $2 );
@@ -706,7 +748,7 @@ equs			:	T_LABEL T_POP_EQUS string
 					{ sym_AddString( $1, $3 ); }
 ;
 
-rsset			:	T_POP_RSSET const
+rsset			:	T_POP_RSSET uconst
 					{ sym_AddSet( "_RS", $2 ); }
 ;
 
@@ -714,28 +756,53 @@ rsreset			:	T_POP_RSRESET
 					{ sym_AddSet( "_RS", 0 ); }
 ;
 
-rl				:	T_LABEL T_POP_RL const
+rl				:	T_LABEL T_POP_RL uconst
 					{
 						sym_AddEqu( $1, sym_GetConstantValue("_RS") );
 						sym_AddSet( "_RS", sym_GetConstantValue("_RS")+4*$3 );
 					}
 ;
 
-rw				:	T_LABEL T_POP_RW const
+rw				:	T_LABEL T_POP_RW uconst
 					{
 						sym_AddEqu( $1, sym_GetConstantValue("_RS") );
 						sym_AddSet( "_RS", sym_GetConstantValue("_RS")+2*$3 );
 					}
 ;
 
-rb				:	T_LABEL T_POP_RB const
+rb				:	T_LABEL T_POP_RB uconst
 					{
 						sym_AddEqu( $1, sym_GetConstantValue("_RS") );
 						sym_AddSet( "_RS", sym_GetConstantValue("_RS")+$3 );
 					}
 ;
 
-ds				:	T_POP_DS const
+union			:	T_POP_UNION {
+						startUnion();
+					};
+
+nextu			:	T_POP_NEXTU {
+						if (nUnionDepth <= 0) {
+							fatalerror("Found NEXTU outside of a UNION construct");
+						}
+	
+						updateUnion();
+					};
+
+endu			:	T_POP_ENDU {
+						if (nUnionDepth <= 0) {
+							fatalerror("Found ENDU outside of a UNION construct");
+						}
+						
+						updateUnion();
+	
+						nUnionDepth--;
+						nPC = unionStart[nUnionDepth] + unionSize[nUnionDepth];
+						pCurrentSection->nPC = nPC;
+						pPCSymbol->nValue = nPC;
+					};
+
+ds				:	T_POP_DS uconst
 					{ out_Skip( $2 ); }
 ;
 
@@ -817,7 +884,7 @@ include			:	T_POP_INCLUDE string
 
 incbin			:	T_POP_INCBIN string
 					{ out_BinaryFile( $2 ); }
-				|	T_POP_INCBIN string ',' const ',' const
+				|	T_POP_INCBIN string ',' uconst ',' uconst
 					{
 						out_BinaryFileSlice( $2, $4, $6 );
 					}
@@ -862,26 +929,47 @@ printf			:	T_POP_PRINTF const
 					}
 ;
 
-if				:	T_POP_IF const
-					{
-						nIFDepth+=1;
-						if( !$2 )
-						{
-							if_skip_to_else();	/* will continue parsing just after ELSE or just at ENDC keyword */
+if				:	T_POP_IF const {
+						nIFDepth++;
+						if (!$2) {
+							if_skip_to_else(); // Continue parsing after ELSE, or at ELIF or ENDC keyword
 						}
+					};
+
+elif			:	T_POP_ELIF const {
+						if (nIFDepth <= 0) {
+							fatalerror("Found ELIF outside an IF construct");
 						}
 
-else			:	T_POP_ELSE
-					{
-						if_skip_to_endc();		/* will continue parsing just at ENDC keyword */
-					}
-;
+						if (skipElif) {
+							// This is for when ELIF is reached at the end of an IF or ELIF block for which the condition was true.
+							if_skip_to_endc(); // Continue parsing at ENDC keyword
 
-endc			:	T_POP_ENDC
-					{
-						nIFDepth-=1;
+						} else {
+							// This is for when ELIF is skipped to because the condition of the previous IF or ELIF block was false.
+							skipElif = true;
+
+							if (!$2) {
+								if_skip_to_else(); // Continue parsing after ELSE, or at ELIF or ENDC keyword
 							}
-;
+						}
+					};
+
+else			:	T_POP_ELSE {
+						if (nIFDepth <= 0) {
+							fatalerror("Found ELSE outside an IF construct");
+						}
+
+						if_skip_to_endc(); // Continue parsing at ENDC keyword
+					};
+
+endc			:	T_POP_ENDC {
+						if (nIFDepth <= 0) {
+							fatalerror("Found ENDC outside an IF construct");
+						}
+
+						nIFDepth--;
+					};
 
 const_3bit		:	const
 					{
@@ -1038,6 +1126,14 @@ relocconst		:	T_ID
 						{ $$ = $2; }
 ;
 
+uconst			:	const
+					{
+						if($1 < 0)
+							fatalerror("Constant mustn't be negative: %d", $1);
+						$$=$1;
+					}
+;
+
 const			:	T_ID							{ $$ = sym_GetConstantValue($1); }
 				|	T_NUMBER 						{ $$ = $1; }
 				|	string						{ $$ = str2int($1); }
@@ -1064,12 +1160,14 @@ const			:	T_ID							{ $$ = sym_GetConstantValue($1); }
 				|	const T_OP_SHL const			{ $$ = $1 << $3; }
 				|	const T_OP_SHR const			{ $$ = $1 >> $3; }
 				|	const T_OP_MUL const			{ $$ = $1 * $3; }
-				|	const T_OP_DIV const			{
+				|	const T_OP_DIV const
+					{
 						if ($3 == 0)
 							fatalerror("division by zero");
 						$$ = $1 / $3;
 					}
-				|	const T_OP_MOD const			{
+				|	const T_OP_MOD const
+					{
 						if ($3 == 0)
 							fatalerror("division by zero");
 						$$ = $1 % $3;
@@ -1109,7 +1207,7 @@ const			:	T_ID							{ $$ = sym_GetConstantValue($1); }
 
 string			:	T_STRING
 					{ strcpy($$,$1); }
-				|	T_OP_STRSUB '(' string ',' const ',' const ')'
+				|	T_OP_STRSUB '(' string ',' uconst ',' uconst ')'
 					{ strncpy($$,$3+$5-1,$7); $$[$7]=0; }
 				|	T_OP_STRCAT '(' string ',' string ')'
 					{ strcpy($$,$3); strcat($$,$5); }
@@ -1123,33 +1221,33 @@ section:
 		{
 			out_NewSection($2,$4);
 		}
-	|	T_POP_SECTION string ',' sectiontype '[' const ']'
+	|	T_POP_SECTION string ',' sectiontype '[' uconst ']'
 		{
 			if( $6>=0 && $6<0x10000 )
 				out_NewAbsSection($2,$4,$6,-1);
 			else
 				yyerror("Address $%x not 16-bit", $6);
 		}
-	|	T_POP_SECTION string ',' sectiontype ',' T_OP_ALIGN '[' const ']'
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_ALIGN '[' uconst ']'
 		{
 			out_NewAlignedSection($2, $4, $8, -1);
 		}
-	|	T_POP_SECTION string ',' sectiontype ',' T_OP_BANK '[' const ']'
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_BANK '[' uconst ']'
 		{
 			bankrangecheck($2, $4, -1, $8);
 		}
-	|	T_POP_SECTION string ',' sectiontype '[' const ']' ',' T_OP_BANK '[' const ']'
+	|	T_POP_SECTION string ',' sectiontype '[' uconst ']' ',' T_OP_BANK '[' uconst ']'
 		{
 			if ($6 < 0 || $6 > 0x10000) {
 				yyerror("Address $%x not 16-bit", $6);
 			}
 			bankrangecheck($2, $4, $6, $11);
 		}
-	|	T_POP_SECTION string ',' sectiontype ',' T_OP_ALIGN '[' const ']' ',' T_OP_BANK '[' const ']'
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_ALIGN '[' uconst ']' ',' T_OP_BANK '[' uconst ']'
 		{
 			out_NewAlignedSection($2, $4, $8, $13);
 		}
-	|	T_POP_SECTION string ',' sectiontype ',' T_OP_BANK '[' const ']' ',' T_OP_ALIGN '[' const ']'
+	|	T_POP_SECTION string ',' sectiontype ',' T_OP_BANK '[' uconst ']' ',' T_OP_ALIGN '[' uconst ']'
 		{
 			out_NewAlignedSection($2, $4, $13, $8);
 		}
@@ -1351,7 +1449,7 @@ z80_ldio		:	T_Z80_LDIO T_MODE_A comma op_mem_ind
 						if( (!rpn_isReloc(&$4))
 						&&	($4.nVal<0 || ($4.nVal>0xFF && $4.nVal<0xFF00) || $4.nVal>0xFFFF) )
 						{
-							yyerror("Source address $%x not in HRAM ($FF00 to $FFFE)", $4.nVal);
+							yyerror("Source address $%x not in $FF00 to $FFFF", $4.nVal);
 						}
 
 						out_AbsByte(0xF0);
@@ -1365,7 +1463,7 @@ z80_ldio		:	T_Z80_LDIO T_MODE_A comma op_mem_ind
 						if( (!rpn_isReloc(&$2))
 						&&	($2.nVal<0 || ($2.nVal>0xFF && $2.nVal<0xFF00) || $2.nVal>0xFFFF) )
 						{
-							yyerror("Destination address $%x not in HRAM ($FF00 to $FFFE)", $2.nVal);
+							yyerror("Destination address $%x not in $FF00 to $FFFF", $2.nVal);
 						}
 
 						out_AbsByte(0xE0);
@@ -1385,7 +1483,10 @@ z80_ld			:	z80_ld_mem
 ;
 
 z80_ld_hl		:	T_Z80_LD T_MODE_HL comma '[' T_MODE_SP const_8bit ']'
-					{ out_AbsByte(0xF8); out_RelByte(&$6); }
+					{
+						out_AbsByte(0xF8); out_RelByte(&$6);
+						warning("'LD HL,[SP+e8]' is obsolete, use 'LD HL,SP+e8' instead.");
+					}
 				|	T_Z80_LD T_MODE_HL comma T_MODE_SP const_8bit
 					{ out_AbsByte(0xF8); out_RelByte(&$5); }
 				|	T_Z80_LD T_MODE_HL comma const_16bit

src/asm/fstack.c

@@ -36,10 +36,13 @@ ULONG nCurrentREPTBlockCount;
 
 ULONG ulMacroReturnValue;
 
+extern char *tzObjectname;
+extern FILE *dependfile;
+
 /*
  * defines for nCurrentStatus
  */
-#define STAT_isInclude 		0
+#define STAT_isInclude		0 /* 'Normal' state as well */
 #define STAT_isMacro		1
 #define STAT_isMacroArg		2
 #define STAT_isREPTBlock	3
@@ -148,6 +151,37 @@ popcontext(void)
 		return (1);
 }
 
+int
+fstk_GetLine(void)
+{
+	struct sContext *pLastFile, **ppLastFile;
+
+	switch (nCurrentStatus) {
+	case STAT_isInclude:
+		/* This is the normal mode, also used when including a file. */
+		return nLineNo;
+	case STAT_isMacro:
+		break; /* Peek top file of the stack */
+	case STAT_isMacroArg:
+		return nLineNo; /* ??? */
+	case STAT_isREPTBlock:
+		break; /* Peek top file of the stack */
+	}
+
+	if ((pLastFile = pFileStack) != NULL) {
+		ppLastFile = &pFileStack;
+		while (pLastFile->pNext) {
+			ppLastFile = &(pLastFile->pNext);
+			pLastFile = *ppLastFile;
+		}
+		return pLastFile->nLine;
+	}
+
+	/* This is only reached if the lexer is in REPT or MACRO mode but there
+	 * are no saved contexts with the origin of said REPT or MACRO. */
+	fatalerror("fstk_GetLine: Internal error.");
+}
+
 int
 yywrap(void)
 {
@@ -198,6 +232,9 @@ fstk_FindFile(char *fname)
 	FILE *f;
 
 	if ((f = fopen(fname, "rb")) != NULL || errno != ENOENT) {
+		if (dependfile) {
+			fprintf(dependfile, "%s: %s\n", tzObjectname, fname);
+		}
 		return f;
 	}
 
@@ -211,6 +248,9 @@ fstk_FindFile(char *fname)
 		}
 
 		if ((f = fopen(path, "rb")) != NULL || errno != ENOENT) {
+			if (dependfile) {
+				fprintf(dependfile, "%s: %s\n", tzObjectname, path);
+			}
 			return f;
 		}
 	}

src/asm/globlex.c

@@ -329,8 +329,13 @@ struct sLexInitString staticstrings[] = {
 
 	{"if", T_POP_IF},
 	{"else", T_POP_ELSE},
+	{"elif", T_POP_ELIF},
 	{"endc", T_POP_ENDC},
 	
+	{"union", T_POP_UNION},
+	{"nextu", T_POP_NEXTU},
+	{"endu", T_POP_ENDU},
+
 	{"wram0", T_SECT_WRAM0},
 	{"vram", T_SECT_VRAM},
 	{"romx", T_SECT_ROMX},
@@ -475,6 +480,7 @@ setuplex(void)
 	lex_FloatAddSecondRange(id, '\\', '\\');
 	lex_FloatAddSecondRange(id, '@', '@');
 	lex_FloatAddSecondRange(id, '#', '#');
+	lex_FloatAddRange(id, '.', '.');
 	lex_FloatAddRange(id, 'a', 'z');
 	lex_FloatAddRange(id, 'A', 'Z');
 	lex_FloatAddRange(id, '0', '9');

src/asm/lexer.c

@@ -535,7 +535,7 @@ yylex_ReadBracketedSymbol(char *dest, size_t index)
 	if (*pLexBuffer == '}')
 		pLexBuffer++;
 	else
-		yyerror("Missing }");
+		fatalerror("Missing }");
 
 	return length;
 }
@@ -601,7 +601,7 @@ yylex_ReadQuotedString()
 	if (*pLexBuffer == '"')
 		pLexBuffer++;
 	else
-		yyerror("Unterminated string");
+		fatalerror("Unterminated string");
 }
 
 ULONG

src/asm/main.c

@@ -12,6 +12,7 @@
 #include "asm/main.h"
 #include "extern/err.h"
 #include "extern/reallocarray.h"
+#include "extern/version.h"
 
 int yyparse(void);
 void setuplex(void);
@@ -22,10 +23,15 @@ char **cldefines;
 
 clock_t nStartClock, nEndClock;
 SLONG nLineNo;
-ULONG nTotalLines, nPass, nPC, nIFDepth, nErrors;
+ULONG nTotalLines, nPass, nPC, nIFDepth, nUnionDepth, nErrors;
+bool skipElif;
+ULONG unionStart[128], unionSize[128];
 
 extern int yydebug;
 
+FILE *dependfile;
+extern char *tzObjectname;
+
 /*
  * Option stack
  */
@@ -273,8 +279,8 @@ static void
 usage(void)
 {
 	printf(
-"Usage: rgbasm [-hvE] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"
-"              [-o outfile] [-p pad_value] file.asm\n");
+"Usage: rgbasm [-EhVvw] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"
+"              [-M dependfile] [-o outfile] [-p pad_value] file.asm\n");
 	exit(1);
 }
 
@@ -288,6 +294,8 @@ main(int argc, char *argv[])
 
 	char *tzMainfile;
 
+	dependfile = NULL;
+
 	cldefines_size = 32;
 	cldefines = reallocarray(cldefines, cldefines_size,
 	                        2 * sizeof(void *));
@@ -317,7 +325,7 @@ main(int argc, char *argv[])
 
 	newopt = CurrentOptions;
 
-	while ((ch = getopt(argc, argv, "b:D:g:hi:o:p:vEw")) != -1) {
+	while ((ch = getopt(argc, argv, "b:D:g:hi:M:o:p:EVvw")) != -1) {
 		switch (ch) {
 		case 'b':
 			if (strlen(optarg) == 2) {
@@ -331,6 +339,9 @@ main(int argc, char *argv[])
 		case 'D':
 			opt_AddDefine(optarg);
 			break;
+		case 'E':
+			newopt.exportall = true;
+			break;
 		case 'g':
 			if (strlen(optarg) == 4) {
 				newopt.gbgfx[0] = optarg[1];
@@ -348,6 +359,11 @@ main(int argc, char *argv[])
 		case 'i':
 			fstk_AddIncludePath(optarg);
 			break;
+		case 'M':
+			if ((dependfile = fopen(optarg, "w")) == NULL) {
+				err(1, "Could not open dependfile %s", optarg);
+			}
+			break;
 		case 'o':
 			out_SetFileName(optarg);
 			break;
@@ -361,17 +377,18 @@ main(int argc, char *argv[])
 				    "between 0 and 0xFF");
 			}
 			break;
+		case 'V':
+			printf("rgbasm %s\n", get_package_version_string());
+			exit(0);
 		case 'v':
 			newopt.verbose = true;
 			break;
-		case 'E':
-			newopt.exportall = true;
-			break;
 		case 'w':
 			newopt.warnings = false;
 			break;
 		default:
 			usage();
+			/* NOTREACHED */
 		}
 	}
 	argc -= optind;
@@ -392,11 +409,20 @@ main(int argc, char *argv[])
 		printf("Assembling %s\n", tzMainfile);
 	}
 
+	if (dependfile) {
+		if (!tzObjectname)
+			errx(1, "Dependency files can only be created if an output object file is specified.\n");
+
+		fprintf(dependfile, "%s: %s\n", tzObjectname, tzMainfile);
+	}
+
 	nStartClock = clock();
 
 	nLineNo = 1;
 	nTotalLines = 0;
 	nIFDepth = 0;
+	skipElif = true;
+	nUnionDepth = 0;
 	nPC = 0;
 	nPass = 1;
 	nErrors = 0;
@@ -420,9 +446,15 @@ main(int argc, char *argv[])
 		errx(1, "Unterminated IF construct (%ld levels)!", nIFDepth);
 	}
 	
+	if (nUnionDepth != 0) {
+		errx(1, "Unterminated UNION construct (%ld levels)!", nUnionDepth);
+	}
+
 	nTotalLines = 0;
 	nLineNo = 1;
 	nIFDepth = 0;
+	skipElif = true;
+	nUnionDepth = 0;
 	nPC = 0;
 	nPass = 2;
 	nErrors = 0;

src/asm/output.c

@@ -15,10 +15,9 @@
 #include "asm/main.h"
 #include "asm/rpn.h"
 #include "asm/fstack.h"
+#include "common.h"
 #include "extern/err.h"
 
-#define SECTIONCHUNK	0x4000
-
 void out_SetCurrentSection(struct Section * pSect);
 
 struct Patch {
@@ -80,6 +79,24 @@ out_PopSection(void)
 		fatalerror("No entries in the section stack");
 }
 
+ULONG
+getmaxsectionsize(ULONG secttype, char * sectname)
+{
+	switch (secttype)
+	{
+		case SECT_ROM0:  return 0x8000; /* If ROMX sections not used. */
+		case SECT_ROMX:  return 0x4000;
+		case SECT_VRAM:  return 0x2000;
+		case SECT_SRAM:  return 0x2000;
+		case SECT_WRAM0: return 0x2000; /* If WRAMX sections not used. */
+		case SECT_WRAMX: return 0x1000;
+		case SECT_OAM:   return 0xA0;
+		case SECT_HRAM:  return 0x7F;
+		default: break;
+	}
+	errx(1, "Section \"%s\" has an invalid section type.", sectname);
+}
+
 /*
  * Count the number of symbols used in this object
  */
@@ -244,10 +261,6 @@ writesymbol(struct sSymbol * pSym, FILE * f)
 		sectid = -1;
 		type = SYM_IMPORT;
 	} else {
-		if (pSym->nType & SYMF_LOCAL) {
-			strcpy(symname, pSym->pScope->tzName);
-			strcat(symname, pSym->tzName);
-		} else
 		strcpy(symname, pSym->tzName);
 
 		if (pSym->nType & SYMF_EXPORT) {
@@ -270,6 +283,9 @@ writesymbol(struct sSymbol * pSym, FILE * f)
 	fputc(type, f);
 
 	if (type != SYM_IMPORT) {
+		fputstring(pSym->tzFileName, f);
+		fputlong(pSym->nFileLine, f);
+
 		fputlong(sectid, f);
 		fputlong(offset, f);
 	}
@@ -441,38 +457,38 @@ checksection(void)
  * this much initialized data
  */
 void
-checkcodesection(SLONG size)
+checkcodesection(void)
 {
 	checksection();
 	if (pCurrentSection->nType != SECT_ROM0 &&
 	    pCurrentSection->nType != SECT_ROMX) {
-		errx(1, "Section '%s' cannot contain code or data (not a "
-		    "ROM0 or ROMX)", pCurrentSection->pzName);
+		fatalerror("Section '%s' cannot contain code or data (not ROM0 or ROMX)",
+		     pCurrentSection->pzName);
+	} else if (nUnionDepth > 0) {
+		fatalerror("UNIONs cannot contain code or data");
 	}
-	if (pCurrentSection->nPC + size > MAXSECTIONSIZE) {
-		/*
-		 * N.B.: This check is not sufficient to ensure the section
-		 * will fit, because there can be multiple sections of this
-		 * type. The definitive check must be done at the linking
-		 * stage.
-		 */
-		errx(1, "Section '%s' is too big (old size %d + %d > %d)",
-		    pCurrentSection->pzName, pCurrentSection->nPC, size,
-		    MAXSECTIONSIZE);
-	}
-	if (((pCurrentSection->nPC % SECTIONCHUNK) >
-	    ((pCurrentSection->nPC + size) % SECTIONCHUNK)) &&
-	    (pCurrentSection->nType == SECT_ROM0 ||
-	    pCurrentSection->nType == SECT_ROMX)) {
-		pCurrentSection->tData = realloc(pCurrentSection->tData,
-		    ((pCurrentSection->nPC + size) / SECTIONCHUNK + 1) *
-		    SECTIONCHUNK);
+}
 
-		if (pCurrentSection->tData == NULL) {
-			err(1, "Could not expand section");
+/*
+ * Check if the section has grown too much.
+ */
+void
+checksectionoverflow(ULONG delta_size)
+{
+	ULONG maxsize = getmaxsectionsize(pCurrentSection->nType,
+					  pCurrentSection->pzName);
+
+	if (pCurrentSection->nPC + delta_size > maxsize) {
+		/*
+		 * This check is here to trap broken code that generates
+		 * sections that are too big and to prevent the assembler from
+		 * generating huge object files or trying to allocate too much
+		 * memory.
+		 * The real check must be done at the linking stage.
+		 */
+		fatalerror("Section '%s' is too big (max size = 0x%X bytes).",
+			pCurrentSection->pzName, maxsize);
 	}
-	}
-	return;
 }
 
 /*
@@ -489,7 +505,9 @@ out_WriteObject(void)
 		struct PatchSymbol *pSym;
 		struct Section *pSect;
 
-		fwrite("RGB4", 1, 4, f);
+		fwrite(RGBDS_OBJECT_VERSION_STRING, 1,
+		       strlen(RGBDS_OBJECT_VERSION_STRING), f);
+
 		fputlong(countsymbols(), f);
 		fputlong(countsections(), f);
 
@@ -580,10 +598,15 @@ out_FindSection(char *pzName, ULONG secttype, SLONG org, SLONG bank, SLONG align
 			pSect->charmap = NULL;
 			pPatchSymbols = NULL;
 
-			if ((pSect->tData = malloc(SECTIONCHUNK)) != NULL) {
-				return (pSect);
-			} else
+			pSect->tData = NULL;
+			if (secttype == SECT_ROM0 || secttype == SECT_ROMX) {
+				/* It is only needed to allocate memory for ROM
+				 * sections. */
+				ULONG sectsize = getmaxsectionsize(secttype, pzName);
+				if ((pSect->tData = malloc(sectsize)) == NULL)
 					fatalerror("Not enough memory for section");
+			}
+			return (pSect);
 		} else
 			fatalerror("Not enough memory for sectionname");
 	} else
@@ -598,6 +621,10 @@ out_FindSection(char *pzName, ULONG secttype, SLONG org, SLONG bank, SLONG align
 void
 out_SetCurrentSection(struct Section * pSect)
 {
+	if (nUnionDepth > 0) {
+		fatalerror("Cannot change the section within a UNION");
+	}
+	
 	pCurrentSection = pSect;
 	nPC = pSect->nPC;
 
@@ -636,12 +663,12 @@ out_NewAlignedSection(char *pzName, ULONG secttype, SLONG alignment, SLONG bank)
 }
 
 /*
- * Output an absolute byte
+ * Output an absolute byte (bypassing ROM/union checks)
  */
 void
-out_AbsByte(int b)
+out_AbsByteBypassCheck(int b)
 {
-	checkcodesection(1);
+	checksectionoverflow(1);
 	b &= 0xFF;
 	if (nPass == 2)
 		pCurrentSection->tData[nPC] = b;
@@ -651,10 +678,21 @@ out_AbsByte(int b)
 	pPCSymbol->nValue += 1;
 }
 
+/*
+ * Output an absolute byte
+ */
+void
+out_AbsByte(int b)
+{
+	checkcodesection();
+	out_AbsByteBypassCheck(b);
+}
+
 void
 out_AbsByteGroup(char *s, int length)
 {
-	checkcodesection(length);
+	checkcodesection();
+	checksectionoverflow(length);
 	while (length--)
 		out_AbsByte(*s++);
 }
@@ -666,13 +704,17 @@ void
 out_Skip(int skip)
 {
 	checksection();
+	checksectionoverflow(skip);
 	if (!((pCurrentSection->nType == SECT_ROM0)
 		|| (pCurrentSection->nType == SECT_ROMX))) {
 		pCurrentSection->nPC += skip;
 		nPC += skip;
 		pPCSymbol->nValue += skip;
+	} else if (nUnionDepth > 0) {
+		while (skip--)
+			out_AbsByteBypassCheck(CurrentOptions.fillchar);
 	} else {
-		checkcodesection(skip);
+		checkcodesection();
 		while (skip--)
 			out_AbsByte(CurrentOptions.fillchar);
 	}
@@ -684,7 +726,8 @@ out_Skip(int skip)
 void
 out_String(char *s)
 {
-	checkcodesection(strlen(s));
+	checkcodesection();
+	checksectionoverflow(strlen(s));
 	while (*s)
 		out_AbsByte(*s++);
 }
@@ -697,7 +740,8 @@ out_String(char *s)
 void
 out_RelByte(struct Expression * expr)
 {
-	checkcodesection(1);
+	checkcodesection();
+	checksectionoverflow(1);
 	if (rpn_isReloc(expr)) {
 		if (nPass == 2) {
 			pCurrentSection->tData[nPC] = 0;
@@ -718,7 +762,8 @@ out_RelByte(struct Expression * expr)
 void
 out_AbsWord(int b)
 {
-	checkcodesection(2);
+	checkcodesection();
+	checksectionoverflow(2);
 	b &= 0xFFFF;
 	if (nPass == 2) {
 		pCurrentSection->tData[nPC] = b & 0xFF;
@@ -738,7 +783,8 @@ out_RelWord(struct Expression * expr)
 {
 	ULONG b;
 
-	checkcodesection(2);
+	checkcodesection();
+	checksectionoverflow(2);
 	b = expr->nVal & 0xFFFF;
 	if (rpn_isReloc(expr)) {
 		if (nPass == 2) {
@@ -760,7 +806,8 @@ out_RelWord(struct Expression * expr)
 void
 out_AbsLong(SLONG b)
 {
-	checkcodesection(sizeof(SLONG));
+	checkcodesection();
+	checksectionoverflow(sizeof(SLONG));
 	if (nPass == 2) {
 		pCurrentSection->tData[nPC] = b & 0xFF;
 		pCurrentSection->tData[nPC + 1] = b >> 8;
@@ -781,7 +828,8 @@ out_RelLong(struct Expression * expr)
 {
 	SLONG b;
 
-	checkcodesection(4);
+	checkcodesection();
+	checksectionoverflow(4);
 	b = expr->nVal;
 	if (rpn_isReloc(expr)) {
 		if (nPass == 2) {
@@ -807,7 +855,8 @@ out_PCRelByte(struct Expression * expr)
 {
 	SLONG b = expr->nVal;
 
-	checkcodesection(1);
+	checkcodesection();
+	checksectionoverflow(1);
 	b = (b & 0xFFFF) - (nPC + 1);
 	if (nPass == 2 && (b < -128 || b > 127))
 		yyerror("PC-relative value must be 8-bit");
@@ -835,7 +884,8 @@ out_BinaryFile(char *s)
 	fsize = ftell(f);
 	fseek(f, 0, SEEK_SET);
 
-	checkcodesection(fsize);
+	checkcodesection();
+	checksectionoverflow(fsize);
 
 	if (nPass == 2) {
 		SLONG dest = nPC;
@@ -879,7 +929,8 @@ out_BinaryFileSlice(char *s, SLONG start_pos, SLONG length)
 
 	fseek(f, start_pos, SEEK_SET);
 
-	checkcodesection(length);
+	checkcodesection();
+	checksectionoverflow(length);
 
 	if (nPass == 2) {
 		SLONG dest = nPC;

src/asm/rgbasm.1

@@ -20,11 +20,12 @@
 .Nd Game Boy assembler
 .Sh SYNOPSIS
 .Nm rgbasm
-.Op Fl Ehvw
+.Op Fl EhVvw
 .Op Fl b Ar chars
 .Op Fl D Ar name Ns Op = Ns Ar value
 .Op Fl g Ar chars
 .Op Fl i Ar path
+.Op Fl M Ar dependfile
 .Op Fl o Ar outfile
 .Op Fl p Ar pad_value
 .Ar file
@@ -61,11 +62,18 @@ The
 option disables this behavior.
 .It Fl i Ar path
 Add an include path.
+.It Fl M Ar dependfile
+Print
+.Xr make 1
+dependencies to
+.Ar dependfile .
 .It Fl o Ar outfile
 Write an object file to the given filename.
 .It Fl p Ar pad_value
 When padding an image, pad with this value.
 The default is 0x00.
+.It Fl V
+Print the version of the program and exit.
 .It Fl v
 Be verbose.
 .It Fl w
@@ -88,10 +96,9 @@ and
 .Xr rgbds 5 ,
 .Xr rgbds 7 ,
 .Xr gbz80 7
-.Pp
-.Lk https://rednex.github.io/rgbds/asm.htm rgbasm assembly commands
 .Sh HISTORY
 .Nm
 was originally written by Carsten S\(/orensen as part of the ASMotor package,
 and was later packaged in RGBDS by Justin Lloyd. It is now maintained by a
-number of contributors at https://github.com/rednex/rgbds.
+number of contributors at
+.Lk https://github.com/rednex/rgbds .

src/asm/rgbasm.5

@@ -12,7 +12,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd April 17, 2017
+.Dd July 22, 2017
 .Dt RGBASM 5
 .Os RGBDS Manual
 .Sh NAME
@@ -223,13 +223,17 @@ GlobalLabel
 AnotherGlobal:
 \&.locallabel
 \&.yet_a_local:
+AnotherGlobal.with_another_local:
 ThisWillBeExported:: ;note the two colons
+ThisWillBeExported.too::
 .Ed
 .Pp
 In the line where a label is defined there musn't be any whitespace before it.
 Local labels are only accessible within the scope they are defined.
 A scope starts after a global label and ends at the next global label.
-Declaring a normal label with :: does an EXPORT at the same time.
+Declaring a label (global or local) with :: does an EXPORT at the same time.
+Local labels can be declared as scope.local or simply as as .local.
+If the former notation is used, the scope must be the actual current scope.
 .Pp
 Labels will normally change their value during the link process and are thus not
 constant.
@@ -271,7 +275,7 @@ Alternatively you can use = as a synonym for SET.
 .Pp
 .Dl COUNT = 2
 .Pp
-.It Sy RSSET , RERESET , RB , RW
+.It Sy RSSET , RSRESET , RB , RW
 .Pp
 The RS group of commands is a handy way of defining structures:
 .Pp
@@ -303,6 +307,8 @@ There are four commands in the RS group of commands:
 .Ic _RS No and adds Ar constexpr No to Ic _RS .
 .It Ic RW Ar constexpr Ta Sets the preceding symbol to
 .Ic _RS No and adds Ar constexpr No * 2 to Ic _RS.
+.It Ic RL Ar constexpr Ta Sets the preceding symbol to
+.Ic _RS No and adds Ar constexpr No * 4 to Ic _RS.
 .El
 .Pp
 Note that a colon (:) following the symbol-name is not allowed.
@@ -340,6 +346,14 @@ String-symbols can also be used to define small one-line macros:
 Note that a colon (:) following the label-name is not allowed.
 String equates can't be exported or imported.
 .Pp
+.Sy Important note :
+An EQUS can be expanded to a string that contains another EQUS
+and it will be expanded as well.
+This means that, if you aren't careful, you may trap the assembler into an
+infinite loop if there's a circular dependency in the expansions.
+Also, a MACRO can have inside an EQUS which references the same MACRO, which has
+the same problem.
+.Pp
 .It Sy MACRO
 .Pp
 One of the best features of an assembler is the ability to write macros for it.
@@ -401,6 +415,14 @@ LoopyMacro: MACRO
             ENDM
 .Ed
 .Pp
+.Sy Important note :
+Since a MACRO can call itself (or a different MACRO that calls the first one)
+there can be problems of circular dependency.
+They trap the assembler in an infinite loop, so you have to be careful when
+using recursion with MACROs.
+Also, a MACRO can have inside an EQUS which references the same MACRO, which has
+the same problem.
+.Pp
 .Sy Macro Arguments
 .Pp
 I'd like LoopyMacro a lot better if I didn't have to pre-load the registers
@@ -521,6 +543,15 @@ The following symbols are defined by the assembler:
 .It Ic EQUS Ta Ic __TIME__ Ta Ta The current time
 .It Ic EQUS Ta Ic __ISO_8601_LOCAL__ Ta ISO 8601 timestamp (local)
 .It Ic EQUS Ta Ic __ISO_8601_UTC__ Ta ISO 8601 timestamp (UTC)
+.It Ic EQU Ta Ic __UTC_YEAR__ Ta Ta Today's year
+.It Ic EQU Ta Ic __UTC_MONTH__ Ta Ta Today's month number, 1-12
+.It Ic EQU Ta Ic __UTC_DAY__ Ta Ta Today's day of the month, 1-31
+.It Ic EQU Ta Ic __UTC_HOUR__ Ta Ta Current hour, 0-23
+.It Ic EQU Ta Ic __UTC_MINUTE__ Ta Ta Current minute, 0-59
+.It Ic EQU Ta Ic __UTC_SECOND__ Ta Ta Current second, 0-59
+.It Ic EQU Ta Ic __RGBDS_MAJOR__ Ta Ta Major version number of RGBDS.
+.It Ic EQU Ta Ic __RGBDS_MINOR__ Ta Ta Minor version number of RGBDS.
+.It Ic EQU Ta Ic __RGBDS_PATCH__ Ta Ta Patch version number of RGBDS.
 .El
 .Pp
 .Sh DEFINING DATA
@@ -584,6 +615,41 @@ You can also include only part of a file with
 The example below includes 256 bytes from data.bin starting from byte 78.
 .Pp
 .Dl INCBIN \[dq]data.bin\[dq],78,256
+.Ss Unions
+Unions allow multiple memory allocations to share the same space in memory,
+like unions in C.
+This allows you to easily reuse memory for different purposes, depending on
+the game's state.
+.Pp
+You create unions using the
+.Ic UNION ,
+.Ic NEXTU
+and
+.Ic ENDU
+keywords.
+.Ic NEXTU
+lets you create a new block of allocations, and you may use it as many times
+within a union as necessary.
+.Pp
+.Bd -literal -offset indent
+UNION
+Name: ds 8
+Nickname: ds 8
+NEXTU
+Health: dw
+Something: ds 3
+Lives: db
+NEXTU
+Temporary: ds 19
+ENDU
+.Ed
+.Pp
+This union will use up 19 bytes, as this is the size of the largest block
+(the last one, containing 'Temporary').
+Of course, as 'Name', 'Health', and 'Temporary' all point to the same memory
+locations, writes to any one of these will affect values read from the others.
+.Pp
+Unions may be used in any section, but code and data may not be included.
 .Sh THE MACRO LANGUAGE
 .Pp
 .Ss Printing things during assembly
@@ -676,27 +742,48 @@ calls infinitely (or until you run out of memory, whichever comes first).
 .Dl INCLUDE \[dq]irq.inc\[dq]
 .Pp
 .Ss Conditional assembling
-The three commands
+The four commands
 .Ic IF ,
-.Ic ELSE
+.Ic ELIF ,
+.Ic ELSE ,
 and
 .Ic ENDC
 are used to conditionally assemble parts of your file.
 This is a powerful feature commonly used in macros.
 .Pp
 .Bd -literal -offset indent
-IF 2+2==4
-PRINTT \[dq]2+2==4\[rs]n\[dq]
+IF NUM < 0
+  PRINTT \[dq]NUM < 0\[rs]n\[dq]
+ELIF NUM == 0
+  PRINTT \[dq]NUM == 0\[rs]n\[dq]
 ELSE
-PRINTT \[dq]2+2!=4\[rs]n\[dq]
+  PRINTT \[dq]NUM > 0\[rs]n\[dq]
 ENDC
 .Ed
 .Pp
 The
+.Ic ELIF
+and
 .Ic ELSE
-block is optional.
-.Ic IF No / Ic ELSE No / Ic ENDC
+blocks are optional.
+.Ic IF No / Ic ELIF No / Ic ELSE No / Ic ENDC
 blocks can be nested.
+.Pp
+Note that if an
+.Ic ELSE
+block is found before an
+.Ic ELIF
+block, the
+.Ic ELIF
+block will be ignored.
+All
+.Ic ELIF
+blocks must go before the
+.Ic ELSE
+block.
+Also, if there is more than one
+.Ic ELSE
+block, all of them but the first one are ignored.
 .Ss Integer and Boolean expressions
 An expression can be composed of many things.
 Expressions are always evaluated using signed 32-bit math.
@@ -928,6 +1015,15 @@ machine.
 .It Sx __ISO_8601_UTC__
 .It Sx __LINE__
 .It Sx __TIME__
+.It Sx __RGBDS_MAJOR__
+.It Sx __RGBDS_MINOR__
+.It Sx __RGBDS_PATCH__
+.It Sx __UTC_YEAR__
+.It Sx __UTC_MONTH__
+.It Sx __UTC_DAY__
+.It Sx __UTC_HOUR__
+.It Sx __UTC_MINUTE__
+.It Sx __UTC_SECOND__
 .It Sx _NARG
 .It Sx _PI
 .It Sx _RS
@@ -942,6 +1038,7 @@ machine.
 .It Sx DIV
 .It Sx DS
 .It Sx DW
+.It Sx ELIF
 .It Sx ELSE
 .It Sx ENDC
 .It Sx ENDM
@@ -970,6 +1067,7 @@ machine.
 .It Sx PUSHS
 .It Sx REPT
 .It Sx RB
+.It Sx RL
 .It Sx ROM0
 .It Sx ROMX
 .It Sx RSRESET
@@ -1005,4 +1103,4 @@ machine.
 was originally written by Carsten S\(/orensen as part of the ASMotor package,
 and was later packaged in RGBDS by Justin Lloyd.
 It is now maintained by a number of contributors at
-https://github.com/rednex/rgbds.
+.Lk https://github.com/rednex/rgbds .

src/asm/symbol.c

@@ -8,11 +8,13 @@
 #include <time.h>
 
 #include "asm/asm.h"
+#include "asm/fstack.h"
 #include "asm/symbol.h"
 #include "asm/main.h"
 #include "asm/mymath.h"
 #include "asm/output.h"
 #include "extern/err.h"
+#include "extern/version.h"
 
 struct sSymbol *tHashedSymbols[HASHSIZE];
 struct sSymbol *pScope = NULL;
@@ -24,8 +26,29 @@ char SavedTIME[256];
 char SavedDATE[256];
 char SavedTIMESTAMP_ISO8601_LOCAL[256];
 char SavedTIMESTAMP_ISO8601_UTC[256];
+char SavedDAY[3];
+char SavedMONTH[3];
+char SavedYEAR[5];
+char SavedHOUR[3];
+char SavedMINUTE[3];
+char SavedSECOND[3];
 bool exportall;
 
+void helper_RemoveLeadingZeros(char * string){
+	char * new_beginning = string;
+
+	while(*new_beginning == '0')
+		new_beginning++;
+
+	if(new_beginning == string)
+		return;
+
+	if(*new_beginning == '\0')
+		new_beginning--;
+
+	memmove(string, new_beginning, strlen(new_beginning) + 1);
+}
+
 SLONG
 Callback_NARG(struct sSymbol * sym)
 {
@@ -87,32 +110,24 @@ createsymbol(char *s)
 		(*ppsym)->pMacro = NULL;
 		(*ppsym)->pSection = NULL;
 		(*ppsym)->Callback = NULL;
+		strcpy((*ppsym)->tzFileName, tzCurrentFileName);
+		(*ppsym)->nFileLine = fstk_GetLine();
 		return (*ppsym);
 	} else {
 		fatalerror("No memory for symbol");
 		return (NULL);
 	}
 }
+
 /*
- * Find a symbol by name and scope
+ * Creates the full name of a local symbol in a given scope, by prepending
+ * the name with the parent symbol's name.
  */
-struct sSymbol *
-findsymbol(char *s, struct sSymbol * scope)
+size_t
+fullSymbolName(char *output, size_t outputSize, char *localName, struct sSymbol *scope)
 {
-	struct sSymbol **ppsym;
-	SLONG hash;
-
-	hash = calchash(s);
-	ppsym = &(tHashedSymbols[hash]);
-
-	while ((*ppsym) != NULL) {
-		if ((strcmp(s, (*ppsym)->tzName) == 0)
-		    && ((*ppsym)->pScope == scope)) {
-			return (*ppsym);
-		} else
-			ppsym = &((*ppsym)->pNext);
-	}
-	return (NULL);
+	struct sSymbol *parent = scope->pScope ? scope->pScope : scope;
+	return snprintf(output, outputSize, "%s%s", parent->tzName, localName);
 }
 
 /*
@@ -123,13 +138,25 @@ findpsymbol(char *s, struct sSymbol * scope)
 {
 	struct sSymbol **ppsym;
 	SLONG hash;
+	char fullname[MAXSYMLEN + 1];
+		
+	if (s[0] == '.' && scope) {
+		fullSymbolName(fullname, sizeof(fullname), s, scope);
+		s = fullname;
+	}
+	
+	char *seperator;
+	if ((seperator = strchr(s, '.'))) {
+		if (strchr(seperator + 1, '.')) {
+			fatalerror("'%s' is a nonsensical reference to a nested local symbol", s);
+		}
+	}
 
 	hash = calchash(s);
 	ppsym = &(tHashedSymbols[hash]);
 
 	while ((*ppsym) != NULL) {
-		if ((strcmp(s, (*ppsym)->tzName) == 0)
-		    && ((*ppsym)->pScope == scope)) {
+		if ((strcmp(s, (*ppsym)->tzName) == 0)) {
 			return (ppsym);
 		} else
 			ppsym = &((*ppsym)->pNext);
@@ -137,6 +164,16 @@ findpsymbol(char *s, struct sSymbol * scope)
 	return (NULL);
 }
 
+/*
+ * Find a symbol by name and scope
+ */
+struct sSymbol *
+findsymbol(char *s, struct sSymbol * scope)
+{
+	struct sSymbol **ppsym = findpsymbol(s, scope);
+	return ppsym ? *ppsym : NULL;
+}
+
 /*
  * Find a symbol by name and scope
  */
@@ -484,7 +521,8 @@ sym_AddEqu(char *tzSym, SLONG value)
 
 		if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
 			if (nsym->nType & SYMF_DEFINED) {
-				yyerror("'%s' already defined", tzSym);
+				yyerror("'%s' already defined in %s(%d)",
+					tzSym, nsym->tzFileName, nsym->nFileLine);
 			}
 		} else
 			nsym = createsymbol(tzSym);
@@ -516,7 +554,8 @@ sym_AddString(char *tzSym, char *tzValue)
 
 	if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
 		if (nsym->nType & SYMF_DEFINED) {
-			yyerror("'%s' already defined", tzSym);
+			yyerror("'%s' already defined in %s(%d)",
+				tzSym, nsym->tzFileName, nsym->nFileLine);
 		}
 	} else
 		nsym = createsymbol(tzSym);
@@ -572,30 +611,16 @@ sym_AddSet(char *tzSym, SLONG value)
 void
 sym_AddLocalReloc(char *tzSym)
 {
-	if ((nPass == 1)
-	    || ((nPass == 2) && (sym_isDefined(tzSym) == 0))) {
-		/* only add local reloc symbols in pass 1 */
-		struct sSymbol *nsym;
-
 	if (pScope) {
-			if ((nsym = findsymbol(tzSym, pScope)) != NULL) {
-				if (nsym->nType & SYMF_DEFINED) {
-					yyerror("'%s' already defined", tzSym);
+		if (strlen(tzSym) + strlen(pScope->tzName) > MAXSYMLEN) {
+			fatalerror("Symbol too long");
 		}
-			} else
-				nsym = createsymbol(tzSym);
 		
-			if (nsym) {
-				nsym->nValue = nPC;
-				nsym->nType |=
-				    SYMF_RELOC | SYMF_LOCAL | SYMF_DEFINED;
-				if (exportall) {
-				   nsym->nType |= SYMF_EXPORT;
-				}
-				nsym->pScope = pScope;
-				nsym->pSection = pCurrentSection;
-			}
-		} else
+		char fullname[MAXSYMLEN + 1];
+		fullSymbolName(fullname, sizeof(fullname), tzSym, pScope);
+		sym_AddReloc(fullname);
+		
+	} else {
 		fatalerror("Local label in main scope");
 	}
 }
@@ -606,14 +631,35 @@ sym_AddLocalReloc(char *tzSym)
 void
 sym_AddReloc(char *tzSym)
 {
+	struct sSymbol* scope = NULL;
+	
 	if ((nPass == 1)
 	    || ((nPass == 2) && (sym_isDefined(tzSym) == 0))) {
 		/* only add reloc symbols in pass 1 */
 		struct sSymbol *nsym;
+		char *localPtr = NULL;
 		
-		if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
+		if ((localPtr = strchr(tzSym, '.')) != NULL) {			
+			if (!pScope) {
+				fatalerror("Local label in main scope");
+			}
+			
+			struct sSymbol *parent = pScope->pScope ? pScope->pScope : pScope;
+			int parentLen = localPtr - tzSym;
+			
+			if (strchr(localPtr + 1, '.') != NULL) {
+				fatalerror("'%s' is a nonsensical reference to a nested local symbol", tzSym);
+			} else if (strlen(parent->tzName) != parentLen || strncmp(tzSym, parent->tzName, parentLen) != 0) {
+				yyerror("Not currently in the scope of '%.*s'", parentLen, tzSym);
+			}
+			
+			scope = parent;
+		}
+
+		if ((nsym = findsymbol(tzSym, scope)) != NULL) {
 			if (nsym->nType & SYMF_DEFINED) {
-				yyerror("'%s' already defined", tzSym);
+				yyerror("'%s' already defined in %s(%d)",
+					tzSym, nsym->tzFileName, nsym->nFileLine);
 			}
 		} else
 			nsym = createsymbol(tzSym);
@@ -621,14 +667,17 @@ sym_AddReloc(char *tzSym)
 		if (nsym) {
 			nsym->nValue = nPC;
 			nsym->nType |= SYMF_RELOC | SYMF_DEFINED;
+			if (localPtr) {
+				nsym->nType |= SYMF_LOCAL;
+			}
 			if (exportall) {
 			   nsym->nType |= SYMF_EXPORT;
 			}
-			nsym->pScope = NULL;
+			nsym->pScope = scope;
 			nsym->pSection = pCurrentSection;
 		}
 	}
-	pScope = findsymbol(tzSym, NULL);
+	pScope = findsymbol(tzSym, scope);
 }
 
 /*
@@ -684,7 +733,7 @@ sym_Export(char *tzSym)
 		/* only export symbols in pass 1 */
 		struct sSymbol *nsym;
 
-		if ((nsym = findsymbol(tzSym, 0)) == NULL)
+		if ((nsym = sym_FindSymbol(tzSym)) == NULL)
 			nsym = createsymbol(tzSym);
 
 		if (nsym)
@@ -692,7 +741,7 @@ sym_Export(char *tzSym)
 	} else {
 		struct sSymbol *nsym;
 
-		if ((nsym = findsymbol(tzSym, 0)) != NULL) {
+		if ((nsym = sym_FindSymbol(tzSym)) != NULL) {
 			if (nsym->nType & SYMF_DEFINED)
 				return;
 		}
@@ -711,7 +760,7 @@ sym_Global(char *tzSym)
 		/* only globalize symbols in pass 2 */
 		struct sSymbol *nsym;
 
-		nsym = findsymbol(tzSym, 0);
+		nsym = sym_FindSymbol(tzSym);
 
 		if ((nsym == NULL) || ((nsym->nType & SYMF_DEFINED) == 0)) {
 			if (nsym == NULL)
@@ -739,7 +788,8 @@ sym_AddMacro(char *tzSym)
 
 		if ((nsym = findsymbol(tzSym, NULL)) != NULL) {
 			if (nsym->nType & SYMF_DEFINED) {
-				yyerror("'%s' already defined", tzSym);
+				yyerror("'%s' already defined in %s(%d)",
+					tzSym, nsym->tzFileName, nsym->nFileLine);
 			}
 		} else
 			nsym = createsymbol(tzSym);
@@ -800,6 +850,15 @@ sym_PrepPass2(void)
 	sym_AddString("__DATE__", SavedDATE);
 	sym_AddString("__ISO_8601_LOCAL__", SavedTIMESTAMP_ISO8601_LOCAL);
 	sym_AddString("__ISO_8601_UTC__", SavedTIMESTAMP_ISO8601_UTC);
+	sym_AddString("__UTC_DAY__", SavedDAY);
+	sym_AddString("__UTC_MONTH__", SavedMONTH);
+	sym_AddString("__UTC_YEAR__", SavedYEAR);
+	sym_AddString("__UTC_HOUR__", SavedHOUR);
+	sym_AddString("__UTC_MINUTE__", SavedMINUTE);
+	sym_AddString("__UTC_SECOND__", SavedSECOND);
+	sym_AddEqu("__RGBDS_MAJOR__", PACKAGE_VERSION_MAJOR);
+	sym_AddEqu("__RGBDS_MINOR__", PACKAGE_VERSION_MINOR);
+	sym_AddEqu("__RGBDS_PATCH__", PACKAGE_VERSION_PATCH);
 	sym_AddSet("_RS", 0);
 
 	sym_AddEqu("_NARG", 0);
@@ -845,6 +904,19 @@ sym_Init(void)
 		struct tm *time_utc = gmtime(&now);
 		strftime(SavedTIMESTAMP_ISO8601_UTC,
 			sizeof(SavedTIMESTAMP_ISO8601_UTC), "\"%FT%TZ\"", time_utc);
+
+		strftime(SavedDAY, sizeof(SavedDAY), "%d", time_utc);
+		strftime(SavedMONTH, sizeof(SavedMONTH), "%m", time_utc);
+		strftime(SavedYEAR, sizeof(SavedYEAR), "%Y", time_utc);
+		strftime(SavedHOUR, sizeof(SavedHOUR), "%H", time_utc);
+		strftime(SavedMINUTE, sizeof(SavedMINUTE), "%M", time_utc);
+		strftime(SavedSECOND, sizeof(SavedSECOND), "%S", time_utc);
+
+		helper_RemoveLeadingZeros(SavedDAY);
+		helper_RemoveLeadingZeros(SavedMONTH);
+		helper_RemoveLeadingZeros(SavedHOUR);
+		helper_RemoveLeadingZeros(SavedMINUTE);
+		helper_RemoveLeadingZeros(SavedSECOND);
 	} else {
 		warnx("Couldn't determine current time.");
 		/* The '?' have to be escaped or they will be treated as
@@ -853,12 +925,24 @@ sym_Init(void)
 		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");
 	}
 
 	sym_AddString("__TIME__", SavedTIME);
 	sym_AddString("__DATE__", SavedDATE);
 	sym_AddString("__ISO_8601_LOCAL__", SavedTIMESTAMP_ISO8601_LOCAL);
 	sym_AddString("__ISO_8601_UTC__", SavedTIMESTAMP_ISO8601_UTC);
+	sym_AddString("__UTC_DAY__", SavedDAY);
+	sym_AddString("__UTC_MONTH__", SavedMONTH);
+	sym_AddString("__UTC_YEAR__", SavedYEAR);
+	sym_AddString("__UTC_HOUR__", SavedHOUR);
+	sym_AddString("__UTC_MINUTE__", SavedMINUTE);
+	sym_AddString("__UTC_SECOND__", SavedSECOND);
 
 	pScope = NULL;
 

src/extern/version.c

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 Antonio Nino Diaz <antonio_nd@outlook.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "extern/version.h"
+
+const char * get_package_version_string(void)
+{
+	static char s[50];
+
+	/* The following conditional should be simplified by the compiler. */
+	if (strlen(BUILD_VERSION_STRING) == 0) {
+		snprintf(s, sizeof(s), "v%d.%d.%d", PACKAGE_VERSION_MAJOR,
+			PACKAGE_VERSION_MINOR, PACKAGE_VERSION_PATCH);
+		return s;
+	} else {
+		return BUILD_VERSION_STRING;
+	}
+}

src/fix/main.c

@@ -22,12 +22,13 @@
 #include <unistd.h>
 
 #include "extern/err.h"
+#include "extern/version.h"
 
 static void
 usage(void)
 {
 	printf(
-"usage: rgbfix [-Ccjsv] [-i game_id] [-k licensee_str] [-l licensee_id]\n"
+"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");
 	exit(1);
@@ -63,13 +64,13 @@ main(int argc, char *argv[])
 	char *id; /* game ID in ASCII */
 	char *newlicensee; /* new licensee ID, two ASCII characters */
 
-	int licensee;  /* old licensee ID */
-	int cartridge; /* cartridge hardware ID */
-	int ramsize;   /* RAM size ID */
-	int version;   /* mask ROM version number */
-	int padvalue;  /* to pad the rom with if it changes size */
+	int licensee = 0;  /* old licensee ID */
+	int cartridge = 0; /* cartridge hardware ID */
+	int ramsize = 0;   /* RAM size ID */
+	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:v")) != -1) {
+	while ((ch = getopt(argc, argv, "Cci:jk:l:m:n:p:sr:t:Vv")) != -1) {
 		switch (ch) {
 		case 'C':
 			coloronly = true;
@@ -177,6 +178,9 @@ main(int argc, char *argv[])
 
 			title = optarg;
 			break;
+		case 'V':
+			printf("rgbfix %s\n", get_package_version_string());
+			exit(0);
 		case 'v':
 			validate = true;
 			break;

src/fix/rgbfix.1

@@ -12,7 +12,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd April 16, 2017
+.Dd April 17, 2017
 .Dt RGBFIX 1
 .Os RGBDS Manual
 .Sh NAME
@@ -20,7 +20,7 @@
 .Nd Game Boy checksum fixer
 .Sh SYNOPSIS
 .Nm rgbfix
-.Op Fl Ccjsv
+.Op Fl CcjsVv
 .Op Fl i Ar game_id
 .Op Fl k Ar licensee_str
 .Op Fl l Ar licensee_id
@@ -108,6 +108,8 @@ or
 .Pc .
 If both this and the game ID are set, the game ID will overwrite the
 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 ,
@@ -153,4 +155,5 @@ SurvivalKids.gbc
 .Nm
 was originally released by Carsten S\(/orensen as a standalone program called
 gbfix, and was later packaged in RGBDS by Justin Lloyd. It is now maintained by
-a number of contributors at https://github.com/rednex/rgbds.
+a number of contributors at
+.Lk https://github.com/rednex/rgbds .

src/gbz80.7

@@ -12,7 +12,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd April 16, 2017
+.Dd April 17, 2017
 .Dt GBZ80 7
 .Os RGBDS Manual
 .Sh NAME
@@ -1821,4 +1821,4 @@ Flags: See
 was originally written by Carsten S\(/orensen as part of the ASMotor package,
 and was later packaged in RGBDS by Justin Lloyd.
 It is now maintained by a number of contributors at
-https://github.com/rednex/rgbds.
+.Lk https://github.com/rednex/rgbds .

src/gfx/main.c

@@ -14,17 +14,19 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#include <getopt.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+
+#include "extern/version.h"
 #include "gfx/main.h"
 
 static void
 usage(void)
 {
 	printf(
-"usage: rgbgfx [-DFfhPTuv] [-d #] [-o outfile] [-p palfile] [-t mapfile]\n"
-"[-x #] infile\n");
+"usage: rgbgfx [-DFfhPTuVv] [-d #] [-o outfile] [-p palfile] [-t mapfile]\n"
+"              [-x #] infile\n");
 	exit(1);
 }
 
@@ -49,27 +51,30 @@ main(int argc, char *argv[])
 
 	depth = 2;
 
-	while((ch = getopt(argc, argv, "DvFfd:hx:Tt:uPp:o:")) != -1) {
+	while((ch = getopt(argc, argv, "Dd:Ffho:Tt:uPp:Vvx:")) != -1) {
 		switch(ch) {
 		case 'D':
 			opts.debug = true;
 			break;
-		case 'v':
-			opts.verbose = true;
+		case 'd':
+			depth = strtoul(optarg, NULL, 0);
 			break;
 		case 'F':
 			opts.hardfix = true;
 		case 'f':
 			opts.fix = true;
 			break;
-		case 'd':
-			depth = strtoul(optarg, NULL, 0);
-			break;
 		case 'h':
 			opts.horizontal = true;
 			break;
-		case 'x':
-			opts.trim = strtoul(optarg, NULL, 0);
+		case 'o':
+			opts.outfile = optarg;
+			break;
+		case 'P':
+			opts.palout = true;
+			break;
+		case 'p':
+			opts.palfile = optarg;
 			break;
 		case 'T':
 			opts.mapout = true;
@@ -80,17 +85,18 @@ main(int argc, char *argv[])
 		case 'u':
 			opts.unique = true;
 			break;
-		case 'P':
-			opts.palout = true;
+		case 'V':
+			printf("rgbgfx %s\n", get_package_version_string());
+			exit(0);
+		case 'v':
+			opts.verbose = true;
 			break;
-		case 'p':
-			opts.palfile = optarg;
-			break;
-		case 'o':
-			opts.outfile = optarg;
+		case 'x':
+			opts.trim = strtoul(optarg, NULL, 0);
 			break;
 		default:
 			usage();
+			/* NOTREACHED */
 		}
 	}
 	argc -= optind;

src/gfx/rgbgfx.1

@@ -12,7 +12,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd April 8, 2017
+.Dd April 17, 2017
 .Dt RGBGFX 1
 .Os RGBDS Manual
 .Sh NAME
@@ -20,7 +20,7 @@
 .Nd Game Boy graphics converter
 .Sh SYNOPSIS
 .Nm rgbgfx
-.Op Fl DfFhPTv
+.Op Fl DfFhPTVv
 .Op Fl o Ar outfile
 .Op Fl d Ar depth
 .Op Fl p Ar palfile
@@ -70,6 +70,8 @@ removing the file extension, and appending
 .Pa .tilemap .
 .It Fl u
 Truncate repeated tiles. Useful with tilemaps.
+.It Fl V
+Print the version of the program and exit.
 .It Fl v
 Verbose.
 Print errors when the command line parameters and the parameters in
@@ -103,4 +105,4 @@ was created by
 .An stag019
 to be included in RGBDS.
 It is now maintained by a number of contributors at
-https://github.com/rednex/rgbds.
+.Lk https://github.com/rednex/rgbds .

src/link/assign.c

@@ -336,7 +336,7 @@ AssignFloatingBankSections(enum eSectionType type)
 
 		if ((org = area_AllocAnyBank(pSection->nByteSize, pSection->nAlign, type)) != -1) {
 			if (options & OPT_OVERLAY) {
-				errx(1, "All sections must be fixed when using overlay");
+				errx(1, "All sections must be fixed when using an overlay file.");
 			}
 			pSection->nOrg = org & 0xFFFF;
 			pSection->nBank = org >> 16;
@@ -512,7 +512,7 @@ AssignSections(void)
 		if (pSection->oAssigned == 0
 			&& pSection->nOrg != -1 && pSection->nBank == -1) {
 			if (options & OPT_OVERLAY) {
-				errx(1, "All sections must be fixed when using overlay");
+				errx(1, "All sections must be fixed when using an overlay file.");
 			}
 			switch (pSection->Type) {
 			case SECT_ROMX:
@@ -566,16 +566,21 @@ CreateSymbolTable(void)
 			    ((pSect->tSymbols[i]->pSection == pSect) ||
 				(pSect->tSymbols[i]->pSection == NULL))) {
 				if (pSect->tSymbols[i]->pSection == NULL)
-					sym_CreateSymbol(pSect->tSymbols[i]->
-					    pzName,
-					    pSect->tSymbols[i]->
-					    nOffset, -1);
+					sym_CreateSymbol(
+						pSect->tSymbols[i]->pzName,
+						pSect->tSymbols[i]->nOffset,
+						-1,
+						pSect->tSymbols[i]->pzObjFileName,
+						pSect->tSymbols[i]->pzFileName,
+						pSect->tSymbols[i]->nFileLine);
 				else
-					sym_CreateSymbol(pSect->tSymbols[i]->
-					    pzName,
-					    pSect->nOrg +
-					    pSect->tSymbols[i]->
-					    nOffset, pSect->nBank);
+					sym_CreateSymbol(
+						pSect->tSymbols[i]->pzName,
+						pSect->nOrg + pSect->tSymbols[i]->nOffset,
+						pSect->nBank,
+						pSect->tSymbols[i]->pzObjFileName,
+						pSect->tSymbols[i]->pzFileName,
+						pSect->tSymbols[i]->nFileLine);
 			}
 		}
 		pSect = pSect->pNext;

src/link/main.c

@@ -4,6 +4,7 @@
 #include <unistd.h>
 
 #include "extern/err.h"
+#include "extern/version.h"
 #include "link/object.h"
 #include "link/output.h"
 #include "link/assign.h"
@@ -33,7 +34,7 @@ static void
 usage(void)
 {
 	printf(
-"usage: rgblink [-twd] [-l linkerscript] [-m mapfile] [-n symfile] [-O overlay]\n"
+"usage: rgblink [-dtVw] [-l linkerscript] [-m mapfile] [-n symfile] [-O overlay]\n"
 "               [-o outfile] [-p pad_value] [-s symbol] file [...]\n");
 	exit(1);
 }
@@ -52,7 +53,7 @@ main(int argc, char *argv[])
 	if (argc == 1)
 		usage();
 
-	while ((ch = getopt(argc, argv, "l:m:n:o:O:p:s:twd")) != -1) {
+	while ((ch = getopt(argc, argv, "dl:m:n:O:o:p:s:tVw")) != -1) {
 		switch (ch) {
 		case 'l':
 			SetLinkerscriptName(optarg);
@@ -76,8 +77,7 @@ main(int argc, char *argv[])
 				errx(1, "Invalid argument for option 'p'");
 			}
 			if (fillchar < 0 || fillchar > 0xFF) {
-				fprintf(stderr, "Argument for option 'p' must be between 0 and 0xFF");
-				exit(1);
+				errx(1, "Argument for option 'p' must be between 0 and 0xFF");
 			}
 			break;
 		case 's':
@@ -98,7 +98,7 @@ main(int argc, char *argv[])
 			 * This option implies OPT_CONTWRAM.
 			 */
 			options |= OPT_DMG_MODE;
-			/* fallthrough */
+			/* FALLTHROUGH */
 		case 'w':
 			/* Set to set WRAM as a single continuous block as on
 			 * DMG. All WRAM sections must be WRAM0 as bankable WRAM
@@ -106,6 +106,9 @@ main(int argc, char *argv[])
 			 * will raise an error. */
 			options |= OPT_CONTWRAM;
 			break;
+		case 'V':
+			printf("rgblink %s\n", get_package_version_string());
+			exit(0);
 		default:
 			usage();
 			/* NOTREACHED */

src/link/object.c

@@ -3,11 +3,13 @@
  *
  */
 
+#include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#include "common.h"
 #include "extern/err.h"
 #include "link/assign.h"
 #include "link/mylink.h"
@@ -116,7 +118,7 @@ AllocSection(void)
  */
 
 struct sSymbol *
-obj_ReadSymbol(FILE * f)
+obj_ReadSymbol(FILE * f, char *tzObjectfile)
 {
 	struct sSymbol *pSym;
 
@@ -126,7 +128,14 @@ obj_ReadSymbol(FILE * f)
 	}
 
 	readasciiz(&pSym->pzName, f);
-	if ((pSym->Type = (enum eSymbolType) fgetc(f)) != SYM_IMPORT) {
+	pSym->Type = (enum eSymbolType)fgetc(f);
+
+	pSym->pzObjFileName = tzObjectfile;
+
+	if (pSym->Type != SYM_IMPORT) {
+		readasciiz(&pSym->pzFileName, f);
+		pSym->nFileLine = readlong(f);
+
 		pSym->nSectionID = readlong(f);
 		pSym->nOffset = readlong(f);
 	}
@@ -160,15 +169,51 @@ obj_ReadRGBSection(FILE * f)
 		errx(1,  "ROMX sections can't be used with option -t.");
 	}
 	if ((options & OPT_CONTWRAM) && (pSection->Type == SECT_WRAMX)) {
-		errx(1, "WRAMX sections can't be used with option -w.");
+		errx(1, "WRAMX sections can't be used with options -w or -d.");
 	}
 	if (options & OPT_DMG_MODE) {
 		/* WRAMX sections are checked for OPT_CONTWRAM */
 		if (pSection->Type == SECT_VRAM && pSection->nBank == 1) {
-			errx(1, "VRAM bank 1 can't be used with option -w.");
+			errx(1, "VRAM bank 1 can't be used with option -d.");
 		}
 	}
 
+	unsigned int maxsize = 0;
+
+	/* Verify that the section isn't too big */
+	switch (pSection->Type)
+	{
+		case SECT_ROM0:
+			maxsize = (options & OPT_TINY) ? 0x8000 : 0x4000;
+			break;
+		case SECT_ROMX:
+			maxsize = 0x4000;
+			break;
+		case SECT_VRAM:
+		case SECT_SRAM:
+			maxsize = 0x2000;
+			break;
+		case SECT_WRAM0:
+			maxsize = (options & OPT_CONTWRAM) ? 0x2000 : 0x1000;
+			break;
+		case SECT_WRAMX:
+			maxsize = 0x1000;
+			break;
+		case SECT_OAM:
+			maxsize = 0xA0;
+			break;
+		case SECT_HRAM:
+			maxsize = 0x7F;
+			break;
+		default:
+			errx(1, "Section \"%s\" has an invalid section type.", pzName);
+			break;
+	}
+	if (pSection->nByteSize > maxsize) {
+		errx(1, "Section \"%s\" is bigger than the max size for that type: 0x%X > 0x%X",
+			pzName, pSection->nByteSize, maxsize);
+	}
+
 	if ((pSection->Type == SECT_ROMX) || (pSection->Type == SECT_ROM0)) {
 		/*
 		 * These sectiontypes contain data...
@@ -183,8 +228,11 @@ obj_ReadRGBSection(FILE * f)
 			SLONG nNumberOfPatches;
 			struct sPatch **ppPatch, *pPatch;
 
-			fread(pSection->pData, sizeof(UBYTE),
-			    pSection->nByteSize, f);
+			if (fread(pSection->pData, sizeof(UBYTE),
+			    pSection->nByteSize, f) != pSection->nByteSize) {
+				err(1, "Read error.");
+                        }
+
 			nNumberOfPatches = readlong(f);
 			ppPatch = &pSection->pPatches;
 
@@ -209,8 +257,10 @@ obj_ReadRGBSection(FILE * f)
 						err(1, NULL);
 					}
 
-					fread(pPatch->pRPN, sizeof(UBYTE),
-					    pPatch->nRPNSize, f);
+					if (fread(pPatch->pRPN, sizeof(UBYTE),
+					    pPatch->nRPNSize, f) != pPatch->nRPNSize) {
+						errx(1, "Read error.");
+					}
 				} else
 					pPatch->pRPN = NULL;
 
@@ -227,7 +277,7 @@ obj_ReadRGBSection(FILE * f)
 }
 
 void
-obj_ReadRGB(FILE * pObjfile)
+obj_ReadRGB(FILE * pObjfile, char *tzObjectfile)
 {
 	struct sSection *pFirstSection;
 	SLONG nNumberOfSymbols, nNumberOfSections, i;
@@ -244,7 +294,7 @@ obj_ReadRGB(FILE * pObjfile)
 		}
 
 		for (i = 0; i < nNumberOfSymbols; i += 1)
-			tSymbols[i] = obj_ReadSymbol(pObjfile);
+			tSymbols[i] = obj_ReadSymbol(pObjfile, tzObjectfile);
 	} else
 		tSymbols = (struct sSymbol **) & dummymem;
 
@@ -289,21 +339,24 @@ obj_ReadRGB(FILE * pObjfile)
 void
 obj_ReadOpenFile(FILE * pObjfile, char *tzObjectfile)
 {
-	char tzHeader[8];
+	char tzHeader[strlen(RGBDS_OBJECT_VERSION_STRING) + 1];
 
-	fread(tzHeader, sizeof(char), 4, pObjfile);
-	tzHeader[4] = 0;
-	if (strncmp(tzHeader, "RGB", 3) == 0) {
-		switch (tzHeader[3]) {
-		case '3':
-		case '4': // V4 supports OAM sections, but is otherwise identical
-			obj_ReadRGB(pObjfile);
-			break;
-		default:
-			errx(1, "'%s' uses an unsupported object file version (%s). Please reassemble it.", tzObjectfile, tzHeader);
+	if (fread(tzHeader, sizeof(char), strlen(RGBDS_OBJECT_VERSION_STRING),
+	    pObjfile) != strlen(RGBDS_OBJECT_VERSION_STRING)) {
+		errx(1, "%s: Read error.", tzObjectfile);
 	}
+
+	tzHeader[strlen(RGBDS_OBJECT_VERSION_STRING)] = 0;
+
+	if (strncmp(tzHeader, RGBDS_OBJECT_VERSION_STRING,
+			strlen(RGBDS_OBJECT_VERSION_STRING)) == 0) {
+		obj_ReadRGB(pObjfile, tzObjectfile);
 	} else {
-		errx(1, "'%s' is not a valid object", tzObjectfile);
+		for (int i = 0; i < strlen(RGBDS_OBJECT_VERSION_STRING); i++)
+			if (!isprint(tzHeader[i]))
+				tzHeader[i] = '?';
+		errx(1, "%s: Invalid file or object file version [%s]",
+			tzObjectfile, tzHeader);
 	}
 }
 
@@ -339,24 +392,3 @@ file_Length(FILE * f)
 
 	return (r);
 }
-
-void
-lib_ReadXLB0(FILE * f)
-{
-	SLONG size;
-
-	size = file_Length(f) - 4;
-	while (size) {
-		char *name;
-
-		size -= readasciiz(&name, f);
-		readword(f);
-		size -= 2;
-		readword(f);
-		size -= 2;
-		size -= readlong(f);
-		size -= 4;
-		obj_ReadOpenFile(f, name);
-		free(name);
-	}
-}

src/link/output.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "extern/err.h"
 #include "link/mylink.h"
 #include "link/mapfile.h"
 #include "link/main.h"
@@ -24,7 +25,10 @@ writehome(FILE * f, FILE * f_overlay)
 
 	if (f_overlay != NULL) {
 		fseek(f_overlay, 0L, SEEK_SET);
-		fread(mem, 1, MaxAvail[BANK_ROM0], f_overlay);
+		if (fread(mem, 1, MaxAvail[BANK_ROM0], f_overlay) !=
+		    MaxAvail[BANK_ROM0]) {
+			warnx("Failed to read data from overlay file.");
+		}
 	} else {
 		memset(mem, fillchar, MaxAvail[BANK_ROM0]);
 	}
@@ -58,7 +62,10 @@ writebank(FILE * f, FILE * f_overlay, SLONG bank)
 
 	if (f_overlay != NULL && bank <= MaxOverlayBank) {
 		fseek(f_overlay, bank*0x4000, SEEK_SET);
-		fread(mem, 1, MaxAvail[bank], f_overlay);
+		if (fread(mem, 1, MaxAvail[bank], f_overlay) !=
+		    MaxAvail[bank]) {
+			warnx("Failed to read data from overlay file.");
+		}
 	} else {
 		memset(mem, fillchar, MaxAvail[bank]);
 	}
@@ -104,18 +111,15 @@ Output(void)
 		if (tzOverlayname) {
 			f_overlay = fopen(tzOverlayname, "rb");
 			if (!f_overlay) {
-				fprintf(stderr, "Failed to open overlay file %s\n", tzOverlayname);
-				exit(1);
+				errx(1, "Failed to open overlay file %s\n", tzOverlayname);
 			}
 			fseek(f_overlay, 0, SEEK_END);
 			if (ftell(f_overlay) % 0x4000 != 0) {
-				fprintf(stderr, "Overlay file must be aligned to 0x4000 bytes\n");
-				exit(1);
+				errx(1, "Overlay file must be aligned to 0x4000 bytes.");
 			}
 			MaxOverlayBank = (ftell(f_overlay) / 0x4000) - 1;
 			if (MaxOverlayBank < 1) {
-				fprintf(stderr, "Overlay file be at least 0x8000 bytes\n");
-				exit(1);
+				errx(1, "Overlay file must be at least 0x8000 bytes.");
 			}
 			if (MaxOverlayBank > MaxBankUsed) {
 				MaxBankUsed = MaxOverlayBank;

src/link/rgblink.1

@@ -20,9 +20,7 @@
 .Nd Game Boy linker
 .Sh SYNOPSIS
 .Nm rgblink
-.Op Fl t
-.Op Fl w
-.Op Fl d
+.Op Fl dtVw
 .Op Fl m Ar mapfile
 .Op Fl n Ar symfile
 .Op Fl O Ar overlayfile
@@ -95,6 +93,8 @@ have to be consistent.
 See
 .Xr rgblink 5
 for more information about its format.
+.It Fl V
+Print the version of the program and exit.
 .El
 .Sh EXAMPLES
 All you need for a basic ROM is an object file, which can be made into a ROM
@@ -119,4 +119,5 @@ to fix these so that the program will actually run in a Game Boy:
 .Nm
 was originally written by Carsten S\(/orensen as part of the ASMotor package,
 and was later packaged in RGBDS by Justin Lloyd. It is now maintained by a
-number of contributors at https://github.com/rednex/rgbds.
+number of contributors at
+.Lk https://github.com/rednex/rgbds .

src/link/rgblink.5

@@ -98,4 +98,5 @@ linkerscript. The address and alignment musn't be set.
 .Nm
 was originally written by Carsten S\(/orensen as part of the ASMotor package,
 and was later packaged in RGBDS by Justin Lloyd. It is now maintained by a
-number of contributors at https://github.com/rednex/rgbds.
+number of contributors at
+.Lk https://github.com/rednex/rgbds .

src/link/symbol.c

@@ -12,8 +12,10 @@
 struct ISymbol {
 	char *pzName;
 	SLONG nValue;
-	SLONG nBank;
-	    //-1 = const
+	SLONG nBank; /* -1 = constant */
+	char tzObjFileName[_MAX_PATH + 1]; /* Object file where the symbol was defined. */
+	char tzFileName[_MAX_PATH + 1]; /* Source file where the symbol was defined. */
+	ULONG nFileLine; /* Line where the symbol was defined. */
 	struct ISymbol *pNext;
 };
 
@@ -76,7 +78,8 @@ sym_GetBank(char *tzName)
 }
 
 void
-sym_CreateSymbol(char *tzName, SLONG nValue, SLONG nBank)
+sym_CreateSymbol(char *tzName, SLONG nValue, SLONG nBank, char *tzObjFileName,
+		char *tzFileName, ULONG nFileLine)
 {
 	if (strcmp(tzName, "@") == 0)
 		return;
@@ -92,7 +95,10 @@ sym_CreateSymbol(char *tzName, SLONG nValue, SLONG nBank)
 			if (nBank == -1)
 				return;
 
-			errx(1, "Symbol '%s' defined more than once", tzName);
+			errx(1, "'%s' in both %s : %s(%d) and %s : %s(%d)",
+				tzName, tzObjFileName, tzFileName, nFileLine,
+				(*ppSym)->tzObjFileName,
+				(*ppSym)->tzFileName, (*ppSym)->nFileLine);
 		}
 	}
 
@@ -102,6 +108,11 @@ sym_CreateSymbol(char *tzName, SLONG nValue, SLONG nBank)
 			(*ppSym)->nValue = nValue;
 			(*ppSym)->nBank = nBank;
 			(*ppSym)->pNext = NULL;
+			strncpy((*ppSym)->tzObjFileName, tzObjFileName,
+				sizeof((*ppSym)->tzObjFileName));
+			strncpy((*ppSym)->tzFileName, tzFileName,
+				sizeof((*ppSym)->tzFileName));
+			(*ppSym)->nFileLine = nFileLine;
 		}
 	}
 }

src/rgbds.5

@@ -12,7 +12,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd April 17, 2017
+.Dd July 22, 2017
 .Dt RGBDS 5
 .Os RGBDS Manual
 .Sh NAME
@@ -42,7 +42,7 @@ is a 0‐terminated string of
 .Bd -literal
 ; Header
 
-BYTE    ID[4]            ; "RGB4"
+BYTE    ID[4]            ; "RGB5"
 LONG    NumberOfSymbols  ; The number of symbols used in this file
 LONG    NumberOfSections ; The number of sections used in this file
 
@@ -59,6 +59,10 @@ REPT    NumberOfSymbols   ; Number of symbols defined in this object file.
 
     IF      Type != 1     ; If symbol is defined in this object file.
 
+        STRING  FileName  ; File where the symbol is defined.
+
+        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.
 
@@ -187,4 +191,4 @@ Symbol ID follows.
 was originally written by Carsten S\(/orensen as part of the ASMotor package,
 and was later packaged in RGBDS by Justin Lloyd.
 It is now maintained by a number of contributors at
-https://github.com/rednex/rgbds.
+.Lk https://github.com/rednex/rgbds .

src/rgbds.7

@@ -47,5 +47,5 @@ implementation of rgbds.
 .It
 2017, Bentley's repository is moved to a neutral name.
 It is now maintained by a number of contributors at
-https://github.com/rednex/rgbds
+.Lk https://github.com/rednex/rgbds .
 .El

test/asm/local-wrong-parent.asm

@@ -0,0 +1,6 @@
+SECTION "sec", ROM0
+
+Parent:
+	db 0
+WrongParent.child
+	db 0

test/asm/local-wrong-parent.out

@@ -0,0 +1,3 @@
+ERROR: local-wrong-parent.asm(5):
+	Not currently in the scope of 'WrongParent'
+error: Assembly aborted in pass 1 (1 errors)!

test/asm/remote-local-explicit.asm

@@ -0,0 +1,7 @@
+SECTION "sec", ROM0
+
+Parent:
+Parent.child::
+	db 0
+NotParent:
+	dw Parent.child

test/asm/remote-local-noexist.asm

@@ -0,0 +1,7 @@
+SECTION "sec", ROM0
+
+Parent:
+.child:
+	db 0
+NotParent:
+	dw Parent.child.fail

test/asm/remote-local-noexist.out

@@ -0,0 +1,2 @@
+ERROR: remote-local-noexist.asm(7):
+	'Parent.child.fail' is a nonsensical reference to a nested local symbol

test/asm/remote-local.asm

@@ -0,0 +1,7 @@
+SECTION "sec", ROM0
+
+Parent:
+.child:
+	db 0
+NotParent:
+	dw Parent.child

test/asm/test.sh

@@ -1,3 +1,4 @@
+#!/bin/sh
 fname=$(mktemp)
 rc=0
 

test/asm/update-refs.sh

@@ -1,3 +1,4 @@
+#!/bin/sh
 fname=$(mktemp)
 
 for i in *.asm; do

test/link/test.sh

@@ -1,3 +1,4 @@
+#!/bin/sh
 otemp=$(mktemp)
 gbtemp=$(mktemp)
 gbtemp2=$(mktemp)

test/link/update-refs.sh

@@ -1,3 +1,4 @@
+#!/bin/sh
 otemp=$(mktemp)
 gbtemp=$(mktemp)
 

test/link/vram-fixed-dmg-mode-d.out

@@ -1 +1 @@
-error: VRAM bank 1 can't be used with option -w.
+error: VRAM bank 1 can't be used with option -d.

test/link/wramx-dmg-mode-d.out

@@ -1 +1 @@
-error: WRAMX sections can't be used with option -w.
+error: WRAMX sections can't be used with options -w or -d.