Implement almost all functionality

Add keywords and identifiers
Add comments
Add number literals
Add strings
Add a lot of new tokens
Add (and clean up) IF etc.
Improve reporting of unexpected chars / garbage bytes
Fix bug with and improved error messages when failing to open file
Add verbose-level messages about how files are opened
Enforce that files finish with a newline
Fix chars returned not being cast to unsigned char (may conflict w/ EOF)
Return null path when no file is open, rather than crash
Unify and improve error printing slightly

Known to be missing: macro expansion, REPT blocks, EQUS expansions

include/asm/asm.h

@@ -27,9 +27,5 @@
 extern uint32_t nTotalLines;
 extern uint32_t nIFDepth;
 extern struct Section *pCurrentSection;
-extern bool oDontExpandStrings;
-
-size_t symvaluetostring(char *dest, size_t maxLength, char *sym,
-			const char *mode);
 
 #endif /* RGBDS_ASM_ASM_H */

include/asm/fstack.h

@@ -32,7 +32,7 @@ struct sContext {
 	uint32_t uniqueID;
 	int32_t nLine;
 	uint32_t nStatus;
-	char *pREPTBlock;
+	char const *pREPTBlock;
 	uint32_t nREPTBlockCount;
 	uint32_t nREPTBlockSize;
 	int32_t nREPTBodyFirstLine;
@@ -47,7 +47,7 @@ void fstk_Dump(void);
 void fstk_DumpToStr(char *buf, size_t len);
 void fstk_AddIncludePath(char *s);
 void fstk_RunMacro(char *s, struct MacroArgs *args);
-void fstk_RunRept(uint32_t count, int32_t nReptLineNo);
+void fstk_RunRept(uint32_t count, int32_t nReptLineNo, char const *body, size_t size);
 /**
  * @param path The user-provided file name
  * @param fullPath The address of a pointer, which will be made to point at the full path

include/asm/lexer.h

@@ -33,10 +33,13 @@ static inline void lexer_SetStateAtEOL(struct LexerState *state)
 struct LexerState *lexer_OpenFile(char const *path);
 struct LexerState *lexer_OpenFileView(void);
 void lexer_DeleteState(struct LexerState *state);
+void lexer_Init(void);
 
 enum LexerMode {
 	LEXER_NORMAL,
-	LEXER_RAW
+	LEXER_RAW,
+	LEXER_SKIP_TO_ELIF,
+	LEXER_SKIP_TO_ENDC
 };
 
 void lexer_SetMode(enum LexerMode mode);
@@ -47,7 +50,7 @@ uint32_t lexer_GetLineNo(void);
 uint32_t lexer_GetColNo(void);
 void lexer_DumpStringExpansions(void);
 int yylex(void);
-void lexer_SkipToBlockEnd(int blockStartToken, int blockEndToken, int endToken,
-			  char const **capture, size_t *size, char const *name);
+void lexer_CaptureBlock(int blockStartToken, int blockEndToken, char const **capture, size_t *size,
+			char const *name);
 
 #endif /* RGBDS_ASM_LEXER_H */

include/asm/symbol.h

@@ -44,8 +44,8 @@ struct Symbol {
 			int32_t (*callback)(void);
 		};
 		struct { /* For SYM_MACRO */
-			uint32_t macroSize;
-			char *macro;
+			size_t macroSize;
+			char const *macro;
 		};
 	};
 
@@ -114,9 +114,10 @@ void sym_Export(char const *symName);
 struct Symbol *sym_AddEqu(char const *symName, int32_t value);
 struct Symbol *sym_AddSet(char const *symName, int32_t value);
 uint32_t sym_GetPCValue(void);
+uint32_t sym_GetConstantSymValue(struct Symbol const *sym);
 uint32_t sym_GetConstantValue(char const *s);
 struct Symbol *sym_FindSymbol(char const *symName);
-struct Symbol *sym_AddMacro(char const *symName, int32_t defLineNo);
+struct Symbol *sym_AddMacro(char const *symName, int32_t defLineNo, char const *body, size_t size);
 struct Symbol *sym_Ref(char const *symName);
 struct Symbol *sym_AddString(char const *symName, char const *value);
 uint32_t sym_GetDefinedValue(char const *s);

include/asm/util.h

@@ -12,6 +12,7 @@
 #include <stdint.h>
 
 uint32_t calchash(const char *s);
+char const *print(char c);
 size_t readUTF8Char(uint8_t *dest, char const *src);
 
 #endif /* RGBDS_UTIL_H */

src/asm/asmy.y

@@ -39,63 +39,7 @@ uint32_t nListCountEmpty;
 char *tzNewMacro;
 uint32_t ulNewMacroSize;
 int32_t nPCOffset;
-bool skipElifs; /* If this is set, ELIFs cannot be executed anymore */
-
-size_t symvaluetostring(char *dest, size_t maxLength, char *symName,
-			const char *mode)
-{
-	size_t length;
-	struct Symbol *sym = sym_FindSymbol(symName);
-
-	if (sym && sym->type == SYM_EQUS) {
-		char const *src = sym_GetStringValue(sym);
-		size_t i;
-
-		if (mode)
-			error("Print types are only allowed for numbers\n");
-
-		for (i = 0; src[i] != 0; i++) {
-			if (i >= maxLength)
-				fatalerror("Symbol value too long to fit buffer\n");
-
-			dest[i] = src[i];
-		}
-
-		length = i;
-
-	} else {
-		uint32_t value = sym_GetConstantValue(symName);
-		int32_t fullLength;
-
-		/* Special cheat for binary */
-		if (mode && !mode[0]) {
-			char binary[33]; /* 32 bits + 1 terminator */
-			char *write_ptr = binary + 32;
-			fullLength = 0;
-			binary[32] = 0;
-			do {
-				*(--write_ptr) = (value & 1) + '0';
-				value >>= 1;
-				fullLength++;
-			} while(value);
-			strncpy(dest, write_ptr, maxLength + 1);
-		} else {
-			fullLength = snprintf(dest, maxLength + 1,
-							  mode ? mode : "$%" PRIX32,
-						      value);
-		}
-
-		if (fullLength < 0) {
-			fatalerror("snprintf encoding error\n");
-		} else {
-			length = (size_t)fullLength;
-			if (length > maxLength)
-				fatalerror("Symbol value too long to fit buffer\n");
-		}
-	}
-
-	return length;
-}
+bool executedIfBlock; /* If this is set, ELIFs cannot be executed anymore */
 
 static uint32_t str2int2(uint8_t *s, int32_t length)
 {
@@ -388,16 +332,69 @@ lines		: /* empty */
 		| lines {
 			nListCountEmpty = 0;
 			nPCOffset = 0;
-		} line '\n' {
+		} line {
 			nTotalLines++;
 		}
 ;
 
-line		: label
-		| label cpu_command
-		| label macro
-		| label simple_pseudoop
-		| pseudoop
+line		: label '\n'
+		| label cpu_command '\n'
+		| label macro '\n'
+		| label simple_pseudoop '\n'
+		| pseudoop '\n'
+		| conditional /* May not necessarily be followed by a newline, see below */
+;
+
+/*
+ * For "logistical" reasons, conditionals must manage newlines themselves.
+ * This is because we need to switch the lexer's mode *after* the newline has been read,
+ * and to avoid causing some grammar conflicts (token reducing is finicky).
+ * This is DEFINITELY one of the more FRAGILE parts of the codebase, handle with care.
+ */
+conditional	: if
+		/* It's important that all of these require being at line start for `skipIfBlock` */
+		| elif
+		| else
+		| endc
+;
+
+if		: T_POP_IF const '\n' {
+			nIFDepth++;
+			executedIfBlock = !!$2;
+			if (!executedIfBlock)
+				lexer_SetMode(LEXER_SKIP_TO_ELIF);
+		}
+;
+
+elif		: T_POP_ELIF const '\n' {
+			if (nIFDepth <= 0)
+				fatalerror("Found ELIF outside an IF construct\n");
+
+			if (executedIfBlock) {
+				lexer_SetMode(LEXER_SKIP_TO_ENDC);
+			} else {
+				executedIfBlock = !!$2;
+				if (!executedIfBlock)
+					lexer_SetMode(LEXER_SKIP_TO_ELIF);
+			}
+		}
+;
+
+else		: T_POP_ELSE '\n' {
+			if (nIFDepth <= 0)
+				fatalerror("Found ELSE outside an IF construct\n");
+
+			if (executedIfBlock)
+				lexer_SetMode(LEXER_SKIP_TO_ENDC);
+		}
+;
+
+endc		: T_POP_ENDC '\n' {
+			if (nIFDepth <= 0)
+				fatalerror("Found ENDC outside an IF construct\n");
+
+			nIFDepth--;
+		}
 ;
 
 scoped_id	: T_ID | T_LOCAL_ID ;
@@ -460,10 +457,6 @@ simple_pseudoop : include
 		| printt
 		| printv
 		| printi
-		| if
-		| elif
-		| else
-		| endc
 		| export
 		| db
 		| dw
@@ -606,9 +599,9 @@ rept		: T_POP_REPT uconst {
 			uint32_t nDefinitionLineNo = lexer_GetLineNo();
 			char const *body;
 			size_t size;
-			lexer_SkipToBlockEnd(T_POP_REPT, T_POP_ENDR, T_POP_ENDR,
-					     &body, &size, "REPT block");
-			fstk_RunRept($2, nDefinitionLineNo);
+			lexer_CaptureBlock(T_POP_REPT, T_POP_ENDR, &body, &size,
+					   "REPT block");
+			fstk_RunRept($2, nDefinitionLineNo, body, size);
 		}
 ;
 
@@ -616,9 +609,9 @@ macrodef	: T_LABEL ':' T_POP_MACRO {
 			int32_t nDefinitionLineNo = lexer_GetLineNo();
 			char const *body;
 			size_t size;
-			lexer_SkipToBlockEnd(T_POP_MACRO, T_POP_ENDM, T_POP_ENDM,
-					     &body, &size, "macro definition");
-			sym_AddMacro($1, nDefinitionLineNo);
+			lexer_CaptureBlock(T_POP_MACRO, T_POP_ENDM, &body, &size,
+					   "macro definition");
+			sym_AddMacro($1, nDefinitionLineNo, body, size);
 		}
 ;
 
@@ -786,72 +779,6 @@ printi		: T_POP_PRINTI const	{ printf("%" PRId32, $2); }
 printf		: T_POP_PRINTF const	{ math_Print($2); }
 ;
 
-if		: T_POP_IF const {
-			nIFDepth++;
-			if (!$2) {
-				/* The function is hardcoded to also stop on T_POP_ELSE and ENDC */
-				lexer_SkipToBlockEnd(T_POP_IF, T_POP_ENDC, T_POP_ELIF,
-						     NULL, NULL, "if block");
-				skipElifs = false;
-			} else {
-				skipElifs = true;
-			}
-		}
-;
-
-elif		: T_POP_ELIF const {
-			if (nIFDepth <= 0)
-				fatalerror("Found ELIF outside an IF construct\n");
-
-			if (skipElifs) {
-				/*
-				 * Executed when ELIF is reached at the end of
-				 * an IF or ELIF block for which the condition
-				 * was true.
-				 *
-				 * Continue parsing at ENDC keyword
-				 */
-				lexer_SkipToBlockEnd(T_POP_IF, T_POP_ENDC, T_POP_ENDC,
-						     NULL, NULL, "elif block");
-			} else {
-				/*
-				 * Executed when ELIF is skipped to because the
-				 * condition of the previous IF or ELIF block
-				 * was false.
-				 */
-
-				if (!$2) {
-					/*
-					 * Continue parsing after ELSE, or at
-					 * ELIF or ENDC keyword.
-					 */
-					lexer_SkipToBlockEnd(T_POP_IF, T_POP_ENDC, T_POP_ELIF,
-							     NULL, NULL, "elif block");
-				} else {
-					skipElifs = true;
-				}
-			}
-		}
-;
-
-else		: T_POP_ELSE {
-			if (nIFDepth <= 0)
-				fatalerror("Found ELSE outside an IF construct\n");
-
-			/* Continue parsing at ENDC keyword */
-			lexer_SkipToBlockEnd(T_POP_IF, T_POP_ENDC, T_POP_ENDC,
-					     NULL, NULL, "else block");
-		}
-;
-
-endc		: T_POP_ENDC {
-			if (nIFDepth <= 0)
-				fatalerror("Found ENDC outside an IF construct\n");
-
-			nIFDepth--;
-		}
-;
-
 const_3bit	: const {
 			int32_t value = $1;
 

src/asm/fstack.c

@@ -41,7 +41,7 @@ static char IncludePaths[MAXINCPATHS][_MAX_PATH + 1];
 static int32_t NextIncPath;
 static uint32_t nMacroCount;
 
-static char *pCurrentREPTBlock;
+static char const *pCurrentREPTBlock;
 static uint32_t nCurrentREPTBlockSize;
 static uint32_t nCurrentREPTBlockCount;
 static int32_t nCurrentREPTBodyFirstLine;
@@ -249,9 +249,11 @@ void fstk_Dump(void)
 			pLastFile->nLine);
 		pLastFile = pLastFile->next;
 	}
+	char const *fileName = lexer_GetFileName();
 
-	fprintf(stderr, "%s(%" PRId32 ",%" PRId32 ")",
-		lexer_GetFileName(), lexer_GetLineNo(), lexer_GetColNo());
+	if (fileName)
+		fprintf(stderr, "%s(%" PRId32 ",%" PRId32 "): ",
+			fileName, lexer_GetLineNo(), lexer_GetColNo());
 }
 
 void fstk_DumpToStr(char *buf, size_t buflen)
@@ -425,15 +427,15 @@ void fstk_RunMacro(char *s, struct MacroArgs *args)
 /*
  * Set up a repeat block for parsing
  */
-void fstk_RunRept(uint32_t count, int32_t nReptLineNo)
+void fstk_RunRept(uint32_t count, int32_t nReptLineNo, char const *body, size_t size)
 {
 	if (count) {
 		pushcontext();
 		macro_SetUniqueID(nMacroCount++);
 		nCurrentREPTBlockCount = count;
 		nCurrentStatus = STAT_isREPTBlock;
-		nCurrentREPTBlockSize = ulNewMacroSize;
-		pCurrentREPTBlock = tzNewMacro;
+		nCurrentREPTBlockSize = size;
+		pCurrentREPTBlock = body;
 		nCurrentREPTBodyFirstLine = nReptLineNo + 1;
 	}
 }

src/asm/main.c

@@ -488,6 +488,7 @@ int main(int argc, char *argv[])
 
 	if (!state)
 		fatalerror("Failed to open main file!\n");
+	lexer_Init();
 	lexer_SetState(state);
 
 	nStartClock = clock();

src/asm/symbol.c

@@ -210,8 +210,6 @@ void sym_Purge(char const *symName)
 			labelScope = NULL;
 
 		hash_RemoveElement(symbols, symbol->name);
-		if (symbol->type == SYM_MACRO)
-			free(symbol->macro);
 		free(symbol);
 	}
 }
@@ -230,7 +228,22 @@ uint32_t sym_GetPCValue(void)
 }
 
 /*
- * Return a constant symbols value
+ * Return a constant symbol's value, assuming it's defined
+ */
+uint32_t sym_GetConstantSymValue(struct Symbol const *sym)
+{
+	if (sym == PCSymbol)
+		return sym_GetPCValue();
+	else if (!sym_IsConstant(sym))
+		error("\"%s\" does not have a constant value\n", sym->name);
+	else
+		return sym_GetValue(sym);
+
+	return 0;
+}
+
+/*
+ * Return a constant symbol's value
  */
 uint32_t sym_GetConstantValue(char const *s)
 {
@@ -238,12 +251,8 @@ uint32_t sym_GetConstantValue(char const *s)
 
 	if (sym == NULL)
 		error("'%s' not defined\n", s);
-	else if (sym == PCSymbol)
-		return sym_GetPCValue();
-	else if (!sym_IsConstant(sym))
-		error("\"%s\" does not have a constant value\n", s);
 	else
-		return sym_GetValue(sym);
+		return sym_GetConstantSymValue(sym);
 
 	return 0;
 }
@@ -468,13 +477,13 @@ void sym_Export(char const *symName)
 /*
  * Add a macro definition
  */
-struct Symbol *sym_AddMacro(char const *symName, int32_t defLineNo)
+struct Symbol *sym_AddMacro(char const *symName, int32_t defLineNo, char const *body, size_t size)
 {
 	struct Symbol *sym = createNonrelocSymbol(symName);
 
 	sym->type = SYM_MACRO;
-	sym->macroSize = ulNewMacroSize;
-	sym->macro = tzNewMacro;
+	sym->macroSize = size;
+	sym->macro = body;
 	updateSymbolFilename(sym);
 	/*
 	 * The symbol is created at the line after the `endm`,

src/asm/util.c

@@ -6,6 +6,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <ctype.h>
 #include <stdint.h>
 
 #include "asm/main.h"
@@ -27,6 +28,37 @@ uint32_t calchash(const char *s)
 	return hash;
 }
 
+char const *print(char c)
+{
+	static char buf[5]; /* '\xNN' + '\0' */
+
+	if (isprint(c)) {
+		buf[0] = c;
+		buf[1] = '\0';
+		return buf;
+	}
+
+	buf[0] = '\\';
+	switch (c) {
+	case '\n':
+		buf[1] = 'n';
+		break;
+	case '\r':
+		buf[1] = 'r';
+		break;
+	case '\t':
+		buf[1] = 't';
+		break;
+
+	default: /* Print as hex */
+		buf[1] = 'x';
+		sprintf(&buf[2], "%02hhx", c);
+		return buf;
+	}
+	buf[2] = '\0';
+	return buf;
+}
+
 size_t readUTF8Char(uint8_t *dest, char const *src)
 {
 	uint32_t state = 0;

src/asm/warning.c

@@ -198,14 +198,14 @@ void processWarningFlag(char const *flag)
 	warnx("Unknown warning `%s`", flag);
 }
 
-void verror(const char *fmt, va_list args, char const *flag)
+void printDiag(const char *fmt, va_list args, char const *type,
+	       char const *flagfmt, char const *flag)
 {
-	fputs("ERROR: ", stderr);
+	fputs(type, stderr);
 	fstk_Dump();
-	fprintf(stderr, flag ? ": [-Werror=%s]\n    " : ":\n    ", flag);
+	fprintf(stderr, flagfmt, flag);
 	vfprintf(stderr, fmt, args);
 	lexer_DumpStringExpansions();
-	nbErrors++;
 }
 
 void error(const char *fmt, ...)
@@ -213,8 +213,9 @@ void error(const char *fmt, ...)
 	va_list args;
 
 	va_start(args, fmt);
-	verror(fmt, args, NULL);
+	printDiag(fmt, args, "ERROR: ", "\n    ", NULL);
 	va_end(args);
+	nbErrors++;
 }
 
 noreturn_ void fatalerror(const char *fmt, ...)
@@ -222,7 +223,7 @@ noreturn_ void fatalerror(const char *fmt, ...)
 	va_list args;
 
 	va_start(args, fmt);
-	verror(fmt, args, NULL);
+	printDiag(fmt, args, "FATAL: ", "\n    ", NULL);
 	va_end(args);
 
 	exit(1);
@@ -240,7 +241,7 @@ void warning(enum WarningID id, char const *fmt, ...)
 		return;
 
 	case WARNING_ERROR:
-		verror(fmt, args, flag);
+		printDiag(fmt, args, "ERROR: ", "[-Werror=%s]\n    ", flag);
 		va_end(args);
 		return;
 
@@ -252,11 +253,7 @@ void warning(enum WarningID id, char const *fmt, ...)
 		break;
 	}
 
-	fputs("warning: ", stderr);
-	fstk_Dump();
-	fprintf(stderr, ": [-W%s]\n    ", flag);
-	vfprintf(stderr, fmt, args);
-	lexer_DumpStringExpansions();
+	printDiag(fmt, args, "warning: ", "[-W%s]\n    ", flag);
 
 	va_end(args);
 }