Implement -Wnumeric-string[=0|1|2] (#935)

Fixes #934

src/asm/parser.y

@@ -52,16 +52,21 @@ static void lowerstring(char *dest, char const *src)
 	*dest = '\0';
 }
 
-static uint32_t str2int2(uint8_t *s, int32_t length)
+static uint32_t str2int2(uint8_t *s, uint32_t length)
 {
-	int32_t i;
+	if (length > 4)
+		warning(WARNING_NUMERIC_STRING_1,
+			"Treating string as a number ignores first %" PRIu32 " character%s\n",
+			length - 4, length == 5 ? "" : "s");
+	else if (length > 1)
+		warning(WARNING_NUMERIC_STRING_2,
+			"Treating %" PRIu32 "-character string as a number\n", length);
+
 	uint32_t r = 0;
 
-	i = length < 4 ? 0 : length - 4;
-	while (i < length) {
+	for (uint32_t i = length < 4 ? 0 : length - 4; i < length; i++) {
 		r <<= 8;
 		r |= s[i];
-		i++;
 	}
 
 	return r;
@@ -1311,7 +1316,7 @@ constlist_8bit_entry : reloc_8bit_no_str {
 		}
 		| string {
 			uint8_t *output = malloc(strlen($1)); /* Cannot be larger than that */
-			int32_t length = charmap_Convert($1, output);
+			uint32_t length = charmap_Convert($1, output);
 
 			sect_AbsByteGroup(output, length);
 			free(output);
@@ -1327,7 +1332,7 @@ constlist_16bit_entry : reloc_16bit_no_str {
 		}
 		| string {
 			uint8_t *output = malloc(strlen($1)); /* Cannot be larger than that */
-			int32_t length = charmap_Convert($1, output);
+			uint32_t length = charmap_Convert($1, output);
 
 			sect_AbsWordGroup(output, length);
 			free(output);
@@ -1344,7 +1349,7 @@ constlist_32bit_entry : relocexpr_no_str {
 		| string {
 			// Charmaps cannot increase the length of a string
 			uint8_t *output = malloc(strlen($1));
-			int32_t length = charmap_Convert($1, output);
+			uint32_t length = charmap_Convert($1, output);
 
 			sect_AbsLongGroup(output, length);
 			free(output);
@@ -1390,7 +1395,7 @@ relocexpr	: relocexpr_no_str
 		| string {
 			// Charmaps cannot increase the length of a string
 			uint8_t *output = malloc(strlen($1));
-			int32_t length = charmap_Convert($1, output);
+			uint32_t length = charmap_Convert($1, output);
 			uint32_t r = str2int2(output, length);
 
 			free(output);

src/asm/rgbasm.1

@@ -243,6 +243,18 @@ Warn when obsolete constructs such as the
 constant or
 .Ic PRINTT
 directive are encountered.
+.It Fl Wnumeric-string=
+Warn when a multi-character string is treated as a number.
+.Fl Wnumeric-string=0
+or
+.Fl Wno-numeric-string
+disables this warning.
+.Fl Wnumeric-string=1
+or just
+.Fl Wnumeric-string
+warns about strings longer than four characters, since four or fewer characters fit within a 32-bit integer.
+.Fl Wnumeric-string=2
+warns about any multi-character string.
 .It Fl Wshift
 Warn when shifting right a negative value.
 Use a division by 2**N instead.

src/asm/section.c

@@ -628,7 +628,7 @@ void sect_AbsByte(uint8_t b)
 	writebyte(b);
 }
 
-void sect_AbsByteGroup(uint8_t const *s, int32_t length)
+void sect_AbsByteGroup(uint8_t const *s, uint32_t length)
 {
 	if (!checkcodesection())
 		return;
@@ -639,7 +639,7 @@ void sect_AbsByteGroup(uint8_t const *s, int32_t length)
 		writebyte(*s++);
 }
 
-void sect_AbsWordGroup(uint8_t const *s, int32_t length)
+void sect_AbsWordGroup(uint8_t const *s, uint32_t length)
 {
 	if (!checkcodesection())
 		return;
@@ -650,7 +650,7 @@ void sect_AbsWordGroup(uint8_t const *s, int32_t length)
 		writeword(*s++);
 }
 
-void sect_AbsLongGroup(uint8_t const *s, int32_t length)
+void sect_AbsLongGroup(uint8_t const *s, uint32_t length)
 {
 	if (!checkcodesection())
 		return;
@@ -664,7 +664,7 @@ void sect_AbsLongGroup(uint8_t const *s, int32_t length)
 /*
  * Skip this many bytes
  */
-void sect_Skip(int32_t skip, bool ds)
+void sect_Skip(uint32_t skip, bool ds)
 {
 	if (!checksection())
 		return;

src/asm/warning.c

@@ -40,6 +40,8 @@ static const enum WarningState defaultWarnings[ARRAY_SIZE(warningStates)] = {
 	[WARNING_SHIFT_AMOUNT]		= WARNING_DISABLED,
 	[WARNING_USER]			= WARNING_ENABLED,
 
+	[WARNING_NUMERIC_STRING_1]	= WARNING_ENABLED,
+	[WARNING_NUMERIC_STRING_2]	= WARNING_DISABLED,
 	[WARNING_TRUNCATION_1]		= WARNING_ENABLED,
 	[WARNING_TRUNCATION_2]		= WARNING_DISABLED,
 };
@@ -86,6 +88,8 @@ static const char * const warningFlags[NB_WARNINGS] = {
 	"user",
 
 	// Parametric warnings
+	"numeric-string",
+	"numeric-string",
 	"truncation",
 	"truncation",
 
@@ -100,6 +104,7 @@ static const struct {
 	uint8_t nbLevels;
 	uint8_t defaultLevel;
 } paramWarnings[] = {
+	{ "numeric-string", 2, 1 },
 	{ "truncation", 2, 2 },
 };
 
@@ -155,6 +160,7 @@ static uint8_t const _wallCommands[] = {
 	WARNING_LONG_STR,
 	WARNING_NESTED_COMMENT,
 	WARNING_OBSOLETE,
+	WARNING_NUMERIC_STRING_1,
 	META_WARNING_DONE
 };
 
@@ -164,6 +170,7 @@ static uint8_t const _wextraCommands[] = {
 	WARNING_MACRO_SHIFT,
 	WARNING_NESTED_COMMENT,
 	WARNING_OBSOLETE,
+	WARNING_NUMERIC_STRING_2,
 	WARNING_TRUNCATION_1,
 	WARNING_TRUNCATION_2,
 	META_WARNING_DONE
@@ -184,6 +191,8 @@ static uint8_t const _weverythingCommands[] = {
 	WARNING_OBSOLETE,
 	WARNING_SHIFT,
 	WARNING_SHIFT_AMOUNT,
+	WARNING_NUMERIC_STRING_1,
+	WARNING_NUMERIC_STRING_2,
 	WARNING_TRUNCATION_1,
 	WARNING_TRUNCATION_2,
 	/* WARNING_USER, */