ref: adcaf4cd46615d424ea328431fbd4feb60d84cf0
parent: 81a77a9b884eb3208ff6c9a38062e184301ae1f6
author: ISSOtm <[email protected]>
date: Sun Aug 2 10:08:26 EDT 2020
Fix crash when no macro args are being used
--- a/src/asm/lexer.c
+++ b/src/asm/lexer.c
@@ -553,7 +553,7 @@
#define LOOKUP_PRE_NEST(exp) (exp)->totalLen += size
#define LOOKUP_POST_NEST(exp) do { \- if (++depth >= nMaxRecursionDepth) \
+ if (name && ++depth >= nMaxRecursionDepth) \
fatalerror("Recursion limit (%u) exceeded\n", nMaxRecursionDepth); \} while (0)
lookupExpansion(parent, distance);
@@ -570,7 +570,7 @@
fatalerror("Unable to allocate new expansion: %s\n", strerror(errno));(*insertPoint)->firstChild = NULL;
(*insertPoint)->next = NULL; /* Expansions are always performed left to right */
- (*insertPoint)->name = strdup(name);
+ (*insertPoint)->name = name ? strdup(name) : NULL;
(*insertPoint)->contents = str;
(*insertPoint)->len = size;
(*insertPoint)->totalLen = size;
@@ -596,6 +596,21 @@
free(expansion);
}
+static char const *expandMacroArg(char name, size_t distance)
+{+ char const *str;
+
+ if (name == '@')
+ str = macro_GetUniqueIDStr();
+ else
+ str = macro_GetArg(name - '0');
+ if (!str)
+ fatalerror("Macro argument '\\%c' not defined\n", name);+
+ beginExpansion(distance, 2, str, strlen(str), NULL);
+ return str;
+}
+
/* If at any point we need more than 255 characters of lookahead, something went VERY wrong. */
static int peek(uint8_t distance)
{@@ -623,27 +638,23 @@
* avoid that duplication. If you have any ideas, please discuss them in an issue or
* pull request. Thank you!
*/
+ unsigned char c = lexerState->ptr[lexerState->offset + distance];
- /* Do not perform expansions while capturing */
- if (!lexerState->capturing) {- /* Scan the new chars for any macro args */
-#define BUF_OFS (lexerState->offset + lexerState->nbChars)
- while (lexerState->nbChars <= distance) {- char c = lexerState->ptr[BUF_OFS];
-
- lexerState->nbChars++;
- if (c == '\\') {- if (lexerState->size <= BUF_OFS)
- break; /* This was the last char in the buffer */
- c = lexerState->ptr[BUF_OFS];
- lexerState->nbChars++;
- if ((c >= '1' && c <= '9') || c == '@')
- fatalerror("Macro arg expansion is not implemented yet\n");- }
+ /* If not capturing and character is a backslash, check for a macro arg */
+ if (!lexerState->capturing && c == '\\') {+ /* We need to read the following character, so check if that's possible */
+ if (lexerState->offset + distance + 1 < lexerState->size) {+ c = lexerState->ptr[lexerState->offset + distance + 1];
+ if (c == '@' || (c >= '1' && c <= '9'))
+ /* Expand the argument and return its first character */
+ c = expandMacroArg(c, distance)[0];
+ /* WARNING: this assumes macro args can't be empty!! */
+ else
+ c = '\\';
}
}
- return (unsigned char)lexerState->ptr[lexerState->offset + distance];
+ return c;
}
if (lexerState->nbChars <= distance) {@@ -677,38 +688,6 @@
#undef readChars
- /* Do not perform expansions when capturing */
- if (!lexerState->capturing) {- /* Scan the newly-inserted chars for any macro args */
- bool escaped = false;
- size_t index = (lexerState->index + lexerState->nbChars) % LEXER_BUF_SIZE;
-
- for (ssize_t i = 0; i < totalCharsRead; i++) {- char c = lexerState->buf[index++];
-
- if (escaped) {- escaped = false;
- if ((c >= '1' && c <= '9') || c == '@')
- fatalerror("Macro arg expansion is not implemented yet\n");- } else if (c == '\\') {- escaped = true;
- }
- if (index == LEXER_BUF_SIZE) /* Wrap around buffer */
- index = 0;
- }
-
- /*
- * If last char read was a backslash, pretend we didn't read it; this is
- * important, otherwise we may miss an expansion that straddles refills
- */
- if (escaped) {- totalCharsRead--;
- /* However, if that prevents having enough characters, error out */
- if (lexerState->nbChars + totalCharsRead <= distance)
- fatalerror("Internal lexer error: cannot read far enough due to backslash\n");- }
- }
-
lexerState->nbChars += totalCharsRead;
/* If there aren't enough chars even after refilling, give up */
@@ -715,7 +694,23 @@
if (lexerState->nbChars <= distance)
return EOF;
}
- return (unsigned char)lexerState->buf[(lexerState->index + distance) % LEXER_BUF_SIZE];
+ unsigned char c = lexerState->buf[(lexerState->index + distance) % LEXER_BUF_SIZE];
+
+ /* If not capturing and character is a backslash, check for a macro arg */
+ if (!lexerState->capturing && c == '\\') {+ /* We need to read the character at `distance + 1`, so check if that's possible */
+ if (lexerState->nbChars == distance + 1) /* We know that ...->nbChars > distance */
+ fatalerror("Internal lexer error: not enough lookahead for macro arg check\n");+ c = lexerState->buf[(lexerState->index + distance + 1) % LEXER_BUF_SIZE];
+ if (c == '@' || (c >= '1' && c <= '9'))
+ /* Expand the argument and return its first character */
+ c = expandMacroArg(c, distance)[0];
+ /* WARNING: this assumes macro args can't be empty!! */
+ else
+ c = '\\';
+ }
+
+ return c;
}
static void shiftChars(uint8_t distance)
@@ -775,6 +770,7 @@
lexerState->offset += distance;
} else {lexerState->index += distance;
+ lexerState->colNo += distance;
/* Wrap around if necessary */
if (lexerState->index >= LEXER_BUF_SIZE)
lexerState->index %= LEXER_BUF_SIZE;
@@ -781,7 +777,6 @@
}
lexerState->nbChars -= distance;
- lexerState->colNo += distance;
}
static int nextChar(void)
@@ -816,12 +811,17 @@
if (!lexerState)
return;
struct Expansion *stack[nMaxRecursionDepth + 1];
+ struct Expansion *expansion;
unsigned int depth = 0;
size_t distance = lexerState->expansionOfs;
-#define LOOKUP_PRE_NEST(exp)
+#define LOOKUP_PRE_NEST(exp) do { \+ /* Only register EQUS expansions, not string args */ \
+ if (expansion->name) \
+ stack[depth++] = expansion; \
+} while (0)
#define LOOKUP_POST_NEST(exp)
- lookupExpansion(stack[depth++], distance);
+ lookupExpansion(expansion, distance);
#undef LOOKUP_PRE_NEST
#undef LOOKUP_POST_NEST
@@ -1513,8 +1513,9 @@
case '\r':
case '\n': /* Do not shift these! */
case EOF:
- if (c != ',')
- lexer_SetMode(LEXER_NORMAL);
+ /* Empty macro args break their expansion, so prevent that */
+ if (i == 0)
+ return c;
if (i == sizeof(yylval.tzString)) {i--;
warning(WARNING_LONG_STR, "Macro argument too long\n");
--- a/src/asm/macro.c
+++ b/src/asm/macro.c
@@ -89,6 +89,9 @@
char const *macro_GetArg(uint32_t i)
{+ if (!macroArgs)
+ return NULL;
+
uint32_t realIndex = i + macroArgs->shift - 1;
return realIndex >= macroArgs->nbArgs ? NULL