shithub: rgbds

Info  •  Files  •  Log  •  Branches

Fix RAW lexer length underflow

Also added an assertion to check against more such overflows

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

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

@@ -792,6 +792,7 @@

 		/* Wrap around if necessary */

 		if (lexerState->index >= LEXER_BUF_SIZE)

 			lexerState->index %= LEXER_BUF_SIZE;

+		assert(lexerState->nbChars >= distance);

 		lexerState->nbChars -= distance;

 	}

 }

@@ -1467,9 +1468,7 @@

 		case '8':

 		case '9':

 			readNumber(10, c - '0');

-			int perhapsPeriod = peek(0);

-

-			if (perhapsPeriod == '.') {

+			if (peek(0) == '.') {

 				shiftChars(1);

 				readFractionalPart();

 			}

@@ -1597,8 +1596,11 @@

 				i--;

 			/* Empty macro args break their expansion, so prevent that */

 			if (i == 0) {

+				/* Return the EOF token, and don't shift a non-existent char! */

+				if (c == EOF)

+					return 0;

 				shiftChars(1);

-				return c == EOF ? 0 : c;

+				return c;

 			}

 			yylval.tzString[i] = '\0';

 			dbgPrint("Read raw string \"%s\"\n", yylval.tzString);