scc

commit df50ac2d78425e98b7eafcb74cf85f0368b05fef
parent b4ad1ce3006663fb4d3292061db9a56fd1200e7e
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed,  6 Apr 2022 20:59:37 +0200

cc1: Do not use input->begin in loops

Since input value can be modified in the loops where
a call to moreinput() can happen it is better to use
input->p because otherwise we can have a dangling
pointer.

Diffstat:
M
src/cmd/cc/cc1/lex.c
 | 
6
++++--

1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/src/cmd/cc/cc1/lex.c b/src/cmd/cc/cc1/lex.c
@@ -902,8 +902,7 @@ discard(void)
 	if (!input)
 		return;
 
-	input->begin = input->p;
-	for (c = yytoken; ; c = *input->begin++) {
+	for (c = yytoken; ; c = *input->p++) {
 		switch (safe) {
 		case END_COMP:
 			if (c == '}')
@@ -926,7 +925,10 @@ discard(void)
 			exit(1);
 	}
 jump:
+	input->begin = input->p;
 	yytoken = c;
+	yytext[0] = c;
+	yytext[1] = '\0';
 	exit(EXIT_FAILURE);
 
 	/*