shithub: rgbds

--- a/include/asm/fstack.h

+++ b/include/asm/fstack.h

@@ -35,6 +35,8 @@

 	uint32_t nREPTBlockSize;

};

+extern unsigned int nMaxRecursionDepth;

 void fstk_RunInclude(char *tzFileName);

 void fstk_RunMacroArg(int32_t s);

 void fstk_Init(char *s);

--- a/include/asm/lexer.h

+++ b/include/asm/lexer.h

@@ -40,6 +40,13 @@

 	LEX_STATE_MACROARGS

};

+struct sStringExpansionPos {

+	char *tzName;

+	char *pBuffer;

+	char *pBufferPos;

+	struct sStringExpansionPos *pParent;

+};

 #define INITIAL		0

 #define macroarg	3

@@ -62,14 +69,16 @@

 void lex_Init(void);

 void lex_AddStrings(const struct sLexInitString *lex);

 void lex_SetBuffer(char *buffer, uint32_t len);

+void lex_BeginStringExpansion(const char *tzName);

 int yywrap(void);

 int yylex(void);

 void yyunput(char c);

-void yyunputstr(char *s);

+void yyunputstr(const char *s);

 void yyskipbytes(uint32_t count);

 void yyunputbytes(uint32_t count);

 extern YY_BUFFER_STATE pCurrentBuffer;

+extern struct sStringExpansionPos *pCurrentStringExpansion;

 void upperstring(char *s);

 void lowerstring(char *s);

--- a/src/asm/fstack.c

+++ b/src/asm/fstack.c

@@ -28,6 +28,8 @@

 #include "types.h"

 static struct sContext *pFileStack;

+static unsigned int nFileStackDepth;

+unsigned int nMaxRecursionDepth;

 static struct sSymbol *pCurrentMacro;

 static YY_BUFFER_STATE CurrentFlexHandle;

 static FILE *pCurrentFile;

@@ -51,6 +53,8 @@

 #define STAT_isMacroArg		2

 #define STAT_isREPTBlock	3

+/* Max context stack size */

/*

  * Context push and pop

*/

@@ -58,6 +62,9 @@

 	struct sContext **ppFileStack;

+	if (++nFileStackDepth > nMaxRecursionDepth)

+		fatalerror("Recursion limit (%d) exceeded", nMaxRecursionDepth);

 	ppFileStack = &pFileStack;

 	while (*ppFileStack)

 		ppFileStack = &((*ppFileStack)->pNext);

@@ -154,6 +161,8 @@

 		fatalerror("%s: Internal error.", __func__);

+	nFileStackDepth--;

 	free(*ppLastFile);

 	*ppLastFile = NULL;

 	yy_switch_to_buffer(CurrentFlexHandle);

@@ -413,6 +422,7 @@

 		if (pCurrentFile == NULL)

 			err(1, "Unable to open file '%s'", pFileName);

+	nFileStackDepth = 0;

 	nMacroCount = 0;

 	nCurrentStatus = STAT_isInclude;

--- a/src/asm/globlex.c

+++ b/src/asm/globlex.c

@@ -188,11 +188,11 @@

/*

- * If the symbol name ends before the end of the macro arg, return true

- * and point "rest" to the rest of the macro arg.

- * Otherwise, return false.

+ * If the symbol name ends before the end of the macro arg,

+ * return a pointer to the rest of the macro arg.

+ * Otherwise, return NULL.

*/

-bool AppendMacroArg(char whichArg, char *dest, size_t *destIndex, char **rest)

+char *AppendMacroArg(char whichArg, char *dest, size_t *destIndex)

 	char *marg;

@@ -222,14 +222,13 @@

 			dest[*destIndex] = ch;

 			(*destIndex)++;

 		} else {

-			*rest = marg;

-			return true;

+			return marg;

 		marg++;

-	return false;

+	return NULL;

 uint32_t ParseSymbol(char *src, uint32_t size)

@@ -251,7 +250,9 @@

*/

 			ch = src[srcIndex++];

-			if (AppendMacroArg(ch, dest, &destIndex, &rest))

+			rest = AppendMacroArg(ch, dest, &destIndex);

+			/* If the symbol's end was in the middle of the token */

+			if (rest)

 				break;

 		} else {

 			if (destIndex >= MAXSYMLEN)

@@ -262,27 +263,34 @@

 	dest[destIndex] = 0;

+	/* Tell the lexer we read all bytes that we did */

+	yyskipbytes(srcIndex);

+	/*

+	 * If an escape's expansion left some chars after the symbol's end,

+	 * such as the `::` in a `Backup\1` expanded to `BackupCamX::`,

+	 * put those into the buffer.

+	 * Note that this NEEDS to be done after the `yyskipbytes` above.

+	 */

+	if (rest)

+		yyunputstr(rest);

+	/* If the symbol is an EQUS, expand it */

 	if (!oDontExpandStrings && sym_isString(dest)) {

 		char *s;

-		yyskipbytes(srcIndex);

+		lex_BeginStringExpansion(dest);

-		if (rest)

-			yyunputstr(rest);

+		/* Feed the symbol's contents into the buffer */

 		yyunputstr(s = sym_GetStringValue(dest));

+		/* Lines inserted this way shall not increase nLineNo */

 		while (*s) {

 			if (*s++ == '\n')

-				nLineNo -= 1;

+				nLineNo--;

 		return 0;

-	yyskipbytes(srcIndex);

-	if (rest)

-		yyunputstr(rest);

 	strcpy(yylval.tzSym, dest);

 	return 1;

--- a/src/asm/lexer.c

+++ b/src/asm/lexer.c

@@ -51,6 +51,9 @@

 uint32_t nFloating;

 enum eLexerState lexerstate = LEX_STATE_NORMAL;

+struct sStringExpansionPos *pCurrentStringExpansion;

+static unsigned int nNbStringExpansions;

 /* UTF-8 byte order mark */

 static const unsigned char bom[BOM_SIZE] = { 0xEF, 0xBB, 0xBF };

@@ -88,19 +91,51 @@

 	*(--pLexBuffer) = c;

-void yyunputstr(char *s)

+void yyunputstr(const char *s)

-	int32_t i, len;

+	int32_t len;

 	len = strlen(s);

-	if (pLexBuffer - len < pLexBufferRealStart)

+	/*

+	 * It would be undefined behavior to subtract `len` from pLexBuffer and

+	 * potentially have it point outside of pLexBufferRealStart's buffer,

+	 * this is why the check is done this way.

+	 * Refer to https://github.com/rednex/rgbds/pull/411#discussion_r319779797

+	 */

+	if (pLexBuffer - pLexBufferRealStart < len)

 		fatalerror("Buffer safety margin exceeded");

-	for (i = len - 1; i >= 0; i--)

-		*(--pLexBuffer) = s[i];

+	pLexBuffer -= len;

+	memcpy(pLexBuffer, s, len);

+/*

+ * Marks that a new string expansion with name `tzName` ends here

+ * Enforces recursion depth

+ */

+void lex_BeginStringExpansion(const char *tzName)

+{

+	if (++nNbStringExpansions > nMaxRecursionDepth)

+		fatalerror("Recursion limit (%d) exceeded", nMaxRecursionDepth);

+	struct sStringExpansionPos *pNewStringExpansion =

+		malloc(sizeof(*pNewStringExpansion));

+	char *tzNewExpansionName = strdup(tzName);

+	if (!pNewStringExpansion || !tzNewExpansionName)

+		fatalerror("Could not allocate memory to expand '%s'",

+			   tzName);

+	pNewStringExpansion->tzName = tzNewExpansionName;

+	pNewStringExpansion->pBuffer = pLexBufferRealStart;

+	pNewStringExpansion->pBufferPos = pLexBuffer;

+	pNewStringExpansion->pParent = pCurrentStringExpansion;

+	pCurrentStringExpansion = pNewStringExpansion;

+}

 void yy_switch_to_buffer(YY_BUFFER_STATE buf)

 	pCurrentBuffer = buf;

@@ -423,6 +458,9 @@

 	nLexMaxLength = 0;

 	nFloating = 0;

+	pCurrentStringExpansion = NULL;

+	nNbStringExpansions = 0;

 void lex_AddStrings(const struct sLexInitString *lex)

@@ -967,12 +1005,30 @@

 int yylex(void)

+	int returnedChar;

 	switch (lexerstate) {

 	case LEX_STATE_NORMAL:

-		return yylex_NORMAL();

+		returnedChar = yylex_NORMAL();

+		break;

 	case LEX_STATE_MACROARGS:

-		return yylex_MACROARGS();

+		returnedChar = yylex_MACROARGS();

+		break;

 	default:

 		fatalerror("%s: Internal error.", __func__);

+	/* Check if string expansions were fully read */

+	while (pCurrentStringExpansion

+	    && pCurrentStringExpansion->pBuffer == pLexBufferRealStart

+	    && pCurrentStringExpansion->pBufferPos <= pLexBuffer) {

+		struct sStringExpansionPos *pParent =

+			pCurrentStringExpansion->pParent;

+		free(pCurrentStringExpansion->tzName);

+		free(pCurrentStringExpansion);

+		pCurrentStringExpansion = pParent;

+		nNbStringExpansions--;

+	}

+	return returnedChar;

--- a/src/asm/main.c

+++ b/src/asm/main.c

@@ -289,7 +289,8 @@

 	printf(

 "usage: rgbasm [-EhLVvw] [-b chars] [-Dname[=value]] [-g chars] [-i path]\n"

-"              [-M dependfile] [-o outfile] [-p pad_value] file.asm\n");

+"              [-M dependfile] [-o outfile] [-p pad_value]\n"

+"              [-r recursion_depth] file.asm\n");

 	exit(1);

@@ -316,6 +317,8 @@

 	/* yydebug=1; */

+	nMaxRecursionDepth = 64;

 	DefaultOptions.gbgfx[0] = '0';

 	DefaultOptions.gbgfx[1] = '1';

 	DefaultOptions.gbgfx[2] = '2';

@@ -333,7 +336,7 @@

 	newopt = CurrentOptions;

-	while ((ch = getopt(argc, argv, "b:D:Eg:hi:LM:o:p:Vvw")) != -1) {

+	while ((ch = getopt(argc, argv, "b:D:Eg:hi:LM:o:p:r:Vvw")) != -1) {

 		switch (ch) {

 		case 'b':

 			if (strlen(optarg) == 2) {

@@ -386,6 +389,12 @@

 			if (newopt.fillchar < 0 || newopt.fillchar > 0xFF)

 				errx(1, "Argument for option 'p' must be between 0 and 0xFF");

+			break;

+		case 'r':

+			nMaxRecursionDepth = strtoul(optarg, &ep, 0);

+			if (optarg[0] == '\0' || *ep != '\0')

+				errx(1, "Invalid argument for option 'r'");

 			break;

 		case 'V':

 			printf("rgbasm %s\n", get_package_version_string());

--- a/src/asm/rgbasm.1

+++ b/src/asm/rgbasm.1

@@ -21,6 +21,7 @@

 .Op Fl M Ar dependfile

 .Op Fl o Ar outfile

 .Op Fl p Ar pad_value

+.Op Fl r Ar recursion_depth

 .Ar file

 .Sh DESCRIPTION

The

@@ -77,6 +78,8 @@

 .It Fl p Ar pad_value

 When padding an image, pad with this value.

 The default is 0x00.

+.It Fl r Ar recursion_depth

+Specifies the recursion depth at which RGBASM will assume being in an infinite loop.

 .It Fl V

 Print the version of the program and exit.

 .It Fl v

--- a/src/asm/rgbasm.5

+++ b/src/asm/rgbasm.5

@@ -455,8 +455,7 @@

 .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.

+If this creates an infinite loop, RGBASM will error out once a certain depth is reached. See the -r command-line option.

 Also, a MACRO can have inside an EQUS which references the same MACRO, which has

 the same problem.

.Pp

--- /dev/null

+++ b/test/asm/equs-recursion.asm

@@ -1,0 +1,2 @@

+recurse EQUS "recurse"

+recurse

\ No newline at end of file

--- /dev/null

+++ b/test/asm/equs-recursion.out

@@ -1,0 +1,2 @@

+ERROR: equs-recursion.asm(2):

+    Recursion limit (64) exceeded

--- /dev/null

+++ b/test/asm/equs-recursion.out.pipe

@@ -1,0 +1,2 @@

+ERROR: -(2):

+    Recursion limit (64) exceeded

--- /dev/null

+++ b/test/asm/include-recursion.asm

@@ -1,0 +1,1 @@

+INCLUDE "include-recursion.asm"

--- /dev/null

+++ b/test/asm/include-recursion.out

@@ -1,0 +1,2 @@

+ERROR: include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1):

+    Recursion limit (64) exceeded

--- /dev/null

+++ b/test/asm/include-recursion.out.pipe

@@ -1,0 +1,2 @@

+ERROR: -(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1) -> include-recursion.asm(1):

+    Recursion limit (64) exceeded

--- /dev/null

+++ b/test/asm/macro-recursion.asm

@@ -1,0 +1,4 @@

+recurse: MACRO

+	recurse

+ENDM

+	recurse

\ No newline at end of file

--- /dev/null

+++ b/test/asm/macro-recursion.out

@@ -1,0 +1,2 @@

+ERROR: macro-recursion.asm(4) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1):

+    Recursion limit (64) exceeded

--- /dev/null

+++ b/test/asm/macro-recursion.out.pipe

@@ -1,0 +1,2 @@

+ERROR: -(4) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1) -> recurse(1):

+    Recursion limit (64) exceeded