Improve error messages

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

Makefile

@@ -15,8 +15,15 @@ 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
-CFLAGS		:= ${WARNFLAGS} -g -std=c99 -D_POSIX_C_SOURCE=200809L -Iinclude
+
+# 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
@@ -44,7 +51,9 @@ 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
+
 
 src/asm/asmy.h: src/asm/asmy.c
 src/asm/locallex.o src/asm/globlex.o src/asm/lexer.o: src/asm/asmy.h
@@ -61,32 +70,35 @@ 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
 
 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 := \
 	src/gfx/gb.o \
 	src/gfx/main.o \
 	src/gfx/makepng.o \
-	src/extern/err.o
+	src/extern/err.o \
+	src/extern/version.o
 
 rgbasm: ${rgbasm_obj}
-	$Q${CC} ${CFLAGS} -o $@ ${rgbasm_obj} -lm
+	$Q${CC} ${REALCFLAGS} -o $@ ${rgbasm_obj} -lm
 
 rgblink: ${rgblink_obj}
-	$Q${CC} ${CFLAGS} -o $@ ${rgblink_obj}
+	$Q${CC} ${REALCFLAGS} -o $@ ${rgblink_obj}
 
 rgbfix: ${rgbfix_obj}
-	$Q${CC} ${CFLAGS} -o $@ ${rgbfix_obj}
+	$Q${CC} ${REALCFLAGS} -o $@ ${rgbfix_obj}
 
 rgbgfx: ${rgbgfx_obj}
-	$Q${CC} ${CFLAGS} ${PNGLDFLAGS} -o $@ ${rgbgfx_obj} ${PNGLDLIBS}
+	$Q${CC} ${REALCFLAGS} ${PNGLDFLAGS} -o $@ ${rgbgfx_obj} ${PNGLDLIBS}
 
 # Rules to process files
 
@@ -96,11 +108,11 @@ rgbgfx: ${rgbgfx_obj}
 .l.o:
 	$Q${RM} $*.c
 	$Q${LEX} ${LFLAGS} -o $*.c $<
-	$Q${CC} ${CFLAGS} -c -o $@ $*.c
+	$Q${CC} ${REALCFLAGS} -c -o $@ $*.c
 	$Q${RM} $*.c
 
 .c.o:
-	$Q${CC} ${CFLAGS} ${PNGCFLAGS} -c -o $@ $<
+	$Q${CC} ${REALCFLAGS} ${PNGCFLAGS} -c -o $@ $<
 
 # Target used to remove all files generated by other Makefile targets.
 

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/symbol.h

@@ -15,7 +15,9 @@ struct sSymbol {
 	struct Section *pSection;
 	ULONG ulMacroSize;
 	char *pMacro;
-	     SLONG(*Callback) (struct sSymbol *);
+	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]));
-	char	*src=pCurrentBuffer->pBuffer;
+}
 
-	while( *src && level )
+void	if_skip_to_else()
-	{
+{
-		if( *src=='\n' )
+	SLONG level = 1;
-			nLineNo+=1;
+	bool inString = false;
+	char *src=pCurrentBuffer->pBuffer;
 
-		if( instring==0 )
+	while (*src && level) {
-		{
+		if (*src == '\n') {
-			if( isIf(src) )
+			nLineNo++;
-			{
-				level+=1;
-				src+=2;
-			}
-			else if( level==1 && isElse(src) )
-			{
-				level-=1;
-				src+=4;
-			}
-			else if( isEndc(src) )
-			{
-				level-=1;
-				if( level!=0 )
-					src+=4;
-			}
-			else
-			{
-				if( *src=='\"' )
-					instring=1;
-				src+=1;
-			}
 		}
-		else
+
-		{
+		if (!inString) {
-			if( *src=='\\' )
+			if (isIf(src)) {
-			{
+				level++;
-				src+=2;
+				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 (*src=='\"') {
+					inString = true;
+				}
+				src++;
 			}
-			else if( *src=='\"' )
+		} else {
-			{
+			switch (*src) {
-				src+=1;
+			case '\\':
-				instring=0;
+				src += 2;
-			}
+				break;
-			else
+
-			{
+			case '\"':
-				src+=1;
+				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 );
+	yyskipbytes(len);
-	yyunput( '\n' );
+	yyunput('\n');
-	nLineNo-=1;
+	nLineNo--;
 }
 
-void	if_skip_to_endc( void )
+void	if_skip_to_endc()
 {
-	SLONG	level=1, len, instring=0;
+	SLONG level = 1;
-	char	*src=pCurrentBuffer->pBuffer;
+	bool inString = false;
+	char *src=pCurrentBuffer->pBuffer;
 
-	while( *src && level )
+	while (*src && level) {
-	{
+		if (*src == '\n') {
-		if( *src=='\n' )
+			nLineNo++;
-			nLineNo+=1;
+		}
 
-		if( instring==0 )
+		if (!inString) {
-		{
+			if (isIf(src)) {
-			if( isIf(src) )
+				level++;
-			{
+				src += 2;
-				level+=1;
+
-				src+=2;
+			} else if (isEndc(src)) {
-			}
+				level--;
-			else if( isEndc(src) )
+				if (level != 0) {
-			{
+					src += 4;
-				level-=1;
+				}
-				if( level!=0 )
+
-					src+=4;
+			} else {
-			}
+				if (*src=='\"') {
-			else
+					inString = true;
-			{
+				}
-				if( *src=='\"' )
+				src++;
-					instring=1;
-				src+=1;
 			}
 		}
-		else
+		else {
-		{
+			switch (*src) {
-			if( *src=='\\' )
+			case '\\':
-			{
+				src += 2;
-				src+=2;
+				break;
-			}
+
-			else if( *src=='\"' )
+			case '\"':
-			{
+				src++;
-				src+=1;
+				inString = false;
-				instring=0;
+				break;
-			}
+
-			else
+			default:
-			{
+				src++;
-				src+=1;
+				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 );
+	yyskipbytes(len);
-	yyunput( '\n' );
+	yyunput('\n');
-	nLineNo-=1;
+	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];
 }
 
 %}
@@ -492,7 +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
@@ -502,6 +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
@@ -627,6 +660,7 @@ simple_pseudoop	:	include
 				|	printt
 				|	printv
 				|	if
+				|	elif
 				|	else
 				|	endc
 				|	import
@@ -639,6 +673,9 @@ simple_pseudoop	:	include
 				|	section
 				|	rsreset
 				|	rsset
+				|	union
+				|	nextu
+				|	endu
 				|	incbin
 				|	charmap
 				|	rept
@@ -740,6 +777,31 @@ rb				:	T_LABEL T_POP_RB uconst
 					}
 ;
 
+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 ); }
 ;
@@ -867,26 +929,47 @@ printf			:	T_POP_PRINTF const
 					}
 ;
 
-if				:	T_POP_IF const
+if				:	T_POP_IF const {
-					{
+						nIFDepth++;
-						nIFDepth+=1;
+						if (!$2) {
-						if( !$2 )
+							if_skip_to_else(); // Continue parsing after ELSE, or at ELIF or ENDC keyword
-						{
-							if_skip_to_else();	/* will continue parsing just after ELSE or just at ENDC keyword */
 						}
-					}
+					};
 
-else			:	T_POP_ELSE
+elif			:	T_POP_ELIF const {
-					{
+						if (nIFDepth <= 0) {
-						if_skip_to_endc();		/* will continue parsing just at ENDC keyword */
+							fatalerror("Found ELIF outside an IF construct");
-					}
+						}
-;
 
-endc			:	T_POP_ENDC
+						if (skipElif) {
-					{
+							// This is for when ELIF is reached at the end of an IF or ELIF block for which the condition was true.
-						nIFDepth-=1;
+							if_skip_to_endc(); // Continue parsing at ENDC keyword
-					}
+
-;
+						} 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
 					{

src/asm/fstack.c

@@ -42,8 +42,8 @@ extern FILE *dependfile;
 /*
  * defines for nCurrentStatus
  */
-#define STAT_isInclude 		0
+#define STAT_isInclude		0 /* 'Normal' state as well */
-#define STAT_isMacro	 		1
+#define STAT_isMacro		1
 #define STAT_isMacroArg		2
 #define STAT_isREPTBlock	3
 
@@ -151,6 +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)
 {

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},

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);
@@ -22,7 +23,9 @@ 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;
 
@@ -276,7 +279,7 @@ static void
 usage(void)
 {
 	printf(
-"Usage: rgbasm [-hvE] [-b chars] [-Dname[=value]] [-g chars] [-i path]\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);
 }
@@ -322,7 +325,7 @@ main(int argc, char *argv[])
 
 	newopt = CurrentOptions;
 
-	while ((ch = getopt(argc, argv, "b:D:g:hi:M: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) {
@@ -336,6 +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];
@@ -371,17 +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;
@@ -414,6 +421,8 @@ main(int argc, char *argv[])
 	nLineNo = 1;
 	nTotalLines = 0;
 	nIFDepth = 0;
+	skipElif = true;
+	nUnionDepth = 0;
 	nPC = 0;
 	nPass = 1;
 	nErrors = 0;
@@ -437,9 +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

@@ -15,6 +15,7 @@
 #include "asm/main.h"
 #include "asm/rpn.h"
 #include "asm/fstack.h"
+#include "common.h"
 #include "extern/err.h"
 
 void out_SetCurrentSection(struct Section * pSect);
@@ -282,6 +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);
 	}
@@ -460,6 +464,8 @@ checkcodesection(void)
 	    pCurrentSection->nType != SECT_ROMX) {
 		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");
 	}
 }
 
@@ -499,7 +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);
 
@@ -613,6 +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;
 
@@ -651,12 +663,11 @@ 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();
 	checksectionoverflow(1);
 	b &= 0xFF;
 	if (nPass == 2)
@@ -667,6 +678,16 @@ 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)
 {
@@ -689,6 +710,9 @@ out_Skip(int skip)
 		pCurrentSection->nPC += skip;
 		nPC += skip;
 		pPCSymbol->nValue += skip;
+	} else if (nUnionDepth > 0) {
+		while (skip--)
+			out_AbsByteBypassCheck(CurrentOptions.fillchar);
 	} else {
 		checkcodesection();
 		while (skip--)

src/asm/rgbasm.1

@@ -20,7 +20,7 @@
 .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
@@ -72,6 +72,8 @@ 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

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
@@ -275,7 +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
@@ -549,6 +549,9 @@ The following symbols are defined by the assembler:
 .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
@@ -612,6 +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
@@ -704,27 +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
+IF NUM < 0
-PRINTT \[dq]2+2==4\[rs]n\[dq]
+  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.
+blocks are optional.
-.Ic IF No / Ic ELSE No / Ic ENDC
+.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.
@@ -956,6 +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
@@ -970,6 +1038,7 @@ machine.
 .It Sx DIV
 .It Sx DS
 .It Sx DW
+.It Sx ELIF
 .It Sx ELSE
 .It Sx ENDC
 .It Sx ENDM

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;
@@ -108,6 +110,8 @@ 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");
@@ -517,7 +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);
@@ -549,7 +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);
@@ -652,7 +658,8 @@ sym_AddReloc(char *tzSym)
 
 		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);
@@ -781,7 +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);
@@ -848,6 +856,9 @@ sym_PrepPass2(void)
 	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);

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 licensee = 0;  /* old licensee ID */
-	int cartridge; /* cartridge hardware ID */
+	int cartridge = 0; /* cartridge hardware ID */
-	int ramsize;   /* RAM size ID */
+	int ramsize = 0;   /* RAM size ID */
-	int version;   /* mask ROM version number */
+	int version = 0;   /* mask ROM version number */
-	int padvalue;  /* to pad the rom with if it changes size */
+	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

@@ -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 ,

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"
+"usage: rgbgfx [-DFfhPTuVv] [-d #] [-o outfile] [-p palfile] [-t mapfile]\n"
-"[-x #] infile\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':
+		case 'd':
-			opts.verbose = true;
+			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':
+		case 'o':
-			opts.trim = strtoul(optarg, NULL, 0);
+			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':
+		case 'V':
-			opts.palout = true;
+			printf("rgbgfx %s\n", get_package_version_string());
+			exit(0);
+		case 'v':
+			opts.verbose = true;
 			break;
-		case 'p':
+		case 'x':
-			opts.palfile = optarg;
+			opts.trim = strtoul(optarg, NULL, 0);
-			break;
-		case 'o':
-			opts.outfile = optarg;
 			break;
 		default:
 			usage();
+			/* NOTREACHED */
 		}
 	}
 	argc -= optind;

src/gfx/rgbgfx.1

@@ -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

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]->
+					sym_CreateSymbol(
-					    pzName,
+						pSect->tSymbols[i]->pzName,
-					    pSect->tSymbols[i]->
+						pSect->tSymbols[i]->nOffset,
-					    nOffset, -1);
+						-1,
+						pSect->tSymbols[i]->pzObjFileName,
+						pSect->tSymbols[i]->pzFileName,
+						pSect->tSymbols[i]->nFileLine);
 				else
-					sym_CreateSymbol(pSect->tSymbols[i]->
+					sym_CreateSymbol(
-					    pzName,
+						pSect->tSymbols[i]->pzName,
-					    pSect->nOrg +
+						pSect->nOrg + pSect->tSymbols[i]->nOffset,
-					    pSect->tSymbols[i]->
+						pSect->nBank,
-					    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");
+				errx(1, "Argument for option 'p' must be between 0 and 0xFF");
-				exit(1);
 			}
 			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);
 	}
@@ -219,8 +228,11 @@ obj_ReadRGBSection(FILE * f)
 			SLONG nNumberOfPatches;
 			struct sPatch **ppPatch, *pPatch;
 
-			fread(pSection->pData, sizeof(UBYTE),
+			if (fread(pSection->pData, sizeof(UBYTE),
-			    pSection->nByteSize, f);
+			    pSection->nByteSize, f) != pSection->nByteSize) {
+				err(1, "Read error.");
+                        }
+
 			nNumberOfPatches = readlong(f);
 			ppPatch = &pSection->pPatches;
 
@@ -245,8 +257,10 @@ obj_ReadRGBSection(FILE * f)
 						err(1, NULL);
 					}
 
-					fread(pPatch->pRPN, sizeof(UBYTE),
+					if (fread(pPatch->pRPN, sizeof(UBYTE),
-					    pPatch->nRPNSize, f);
+					    pPatch->nRPNSize, f) != pPatch->nRPNSize) {
+						errx(1, "Read error.");
+					}
 				} else
 					pPatch->pRPN = NULL;
 
@@ -263,7 +277,7 @@ obj_ReadRGBSection(FILE * f)
 }
 
 void
-obj_ReadRGB(FILE * pObjfile)
+obj_ReadRGB(FILE * pObjfile, char *tzObjectfile)
 {
 	struct sSection *pFirstSection;
 	SLONG nNumberOfSymbols, nNumberOfSections, i;
@@ -280,7 +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;
 
@@ -325,21 +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);
+	if (fread(tzHeader, sizeof(char), strlen(RGBDS_OBJECT_VERSION_STRING),
-	tzHeader[4] = 0;
+	    pObjfile) != strlen(RGBDS_OBJECT_VERSION_STRING)) {
-	if (strncmp(tzHeader, "RGB", 3) == 0) {
+		errx(1, "%s: Read error.", tzObjectfile);
-		switch (tzHeader[3]) {
+	}
-		case '3':
+
-		case '4': // V4 supports OAM sections, but is otherwise identical
+	tzHeader[strlen(RGBDS_OBJECT_VERSION_STRING)] = 0;
-			obj_ReadRGB(pObjfile);
+
-			break;
+	if (strncmp(tzHeader, RGBDS_OBJECT_VERSION_STRING,
-		default:
+			strlen(RGBDS_OBJECT_VERSION_STRING)) == 0) {
-			errx(1, "'%s' uses an unsupported object file version (%s). Please reassemble it.", tzObjectfile, tzHeader);
+		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);
 	}
 }
 

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);
+				errx(1, "Failed to open overlay file %s\n", tzOverlayname);
-				exit(1);
 			}
 			fseek(f_overlay, 0, SEEK_END);
 			if (ftell(f_overlay) % 0x4000 != 0) {
-				fprintf(stderr, "Overlay file must be aligned to 0x4000 bytes\n");
+				errx(1, "Overlay file must be aligned to 0x4000 bytes.");
-				exit(1);
 			}
 			MaxOverlayBank = (ftell(f_overlay) / 0x4000) - 1;
 			if (MaxOverlayBank < 1) {
-				fprintf(stderr, "Overlay file be at least 0x8000 bytes\n");
+				errx(1, "Overlay file must be at least 0x8000 bytes.");
-				exit(1);
 			}
 			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 dtVw
-.Op Fl w
-.Op Fl d
 .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

src/link/symbol.c

@@ -12,8 +12,10 @@
 struct ISymbol {
 	char *pzName;
 	SLONG nValue;
-	SLONG nBank;
+	SLONG nBank; /* -1 = constant */
-	    //-1 = const
+	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.
 

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)