Re: [bug, bisected, -chrisl] Segfault at evaluate.c:341

[Al Viro <viro@ZenIV.linux.org.uk>]

On Thu, Mar 19, 2009 at 04:11:41PM -0700, Christopher Li wrote:
> Thanks Al,
> 
> I will apply it later tonight.
> 
> If no one beats to me, I will try to add the warning for using preprocessor
> directive inside macro expansion. It should be a better error message
> than the current one.

Well...  patch below would give more or less close approximation to the
current set of nasal demons produced by gcc in these situations + error
when that crap happens.
Warning: it might make things slower, and it needs testing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
diff --git a/pre-process.c b/pre-process.c
index cf53893..df6cca4 100644
--- a/pre-process.c
+++ b/pre-process.c
@@ -193,13 +193,36 @@ static void expand_list(struct token **list)
 	}
 }
 
+static void preprocessor_line(struct stream *stream, struct token **line);
+
 static struct token *collect_arg(struct token *prev, int vararg, struct position *pos)
 {
+	struct stream *stream = input_streams + prev->pos.stream;
 	struct token **p = &prev->next;
 	struct token *next;
 	int nesting = 0;
 
 	while (!eof_token(next = scan_next(p))) {
+		if (next->pos.newline && match_op(next, '#')) {
+			if (!next->pos.noexpand) {
+				sparse_error(next->pos,
+					     "directive in argument list");
+				preprocessor_line(stream, p);
+				__free_token(next);	/* Free the '#' token */
+				continue;
+			}
+		}
+		switch (token_type(next)) {
+		case TOKEN_STREAMEND:
+		case TOKEN_STREAMBEGIN:
+			*p = &eof_token_entry;
+			return next;
+		}
+		if (false_nesting) {
+			*p = next->next;
+			__free_token(next);
+			continue;
+		}
 		if (match_op(next, '(')) {
 			nesting++;
 		} else if (match_op(next, ')')) {