Module Name: src
Committed By: rillig
Date: Sat Jan 21 08:04:43 UTC 2023
Modified Files:
src/tests/usr.bin/xlint/lint1: gcc_typeof.c
src/usr.bin/xlint/lint1: cgram.y
Log Message:
lint: fix null pointer dereference on invalid argument to __typeof__
To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/tests/usr.bin/xlint/lint1/gcc_typeof.c
cvs rdiff -u -r1.426 -r1.427 src/usr.bin/xlint/lint1/cgram.y
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/usr.bin/xlint/lint1/gcc_typeof.c
diff -u src/tests/usr.bin/xlint/lint1/gcc_typeof.c:1.4 src/tests/usr.bin/xlint/lint1/gcc_typeof.c:1.5
--- src/tests/usr.bin/xlint/lint1/gcc_typeof.c:1.4 Sun Apr 10 12:14:10 2022
+++ src/tests/usr.bin/xlint/lint1/gcc_typeof.c Sat Jan 21 08:04:43 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: gcc_typeof.c,v 1.4 2022/04/10 12:14:10 rillig Exp $ */
+/* $NetBSD: gcc_typeof.c,v 1.5 2023/01/21 08:04:43 rillig Exp $ */
# 3 "gcc_typeof.c"
/*
@@ -41,3 +41,16 @@ cast(double(*fn)(double))
*/
int *volatile lock;
const volatile __typeof__(lock) *lock_pointer = &lock;
+
+/*
+ * Before cgram.y 1.427 from 2023-01-21, lint crashed due to a null pointer
+ * dereference if the __typeof__ operator had an invalid argument. Seen in
+ * _fc_atomic_ptr_cmpexch from fontconfig, which uses <stdatomic.h> provided
+ * by GCC, which in turn uses __auto_type and __typeof__, and lint doesn't
+ * know about __auto_type.
+ */
+void _fc_atomic_ptr_cmpexch(void)
+{
+ /* expect+1: error: 'expr' undefined [99] */
+ __typeof__ (expr) var = 0;
+}
Index: src/usr.bin/xlint/lint1/cgram.y
diff -u src/usr.bin/xlint/lint1/cgram.y:1.426 src/usr.bin/xlint/lint1/cgram.y:1.427
--- src/usr.bin/xlint/lint1/cgram.y:1.426 Sun Jan 15 00:05:38 2023
+++ src/usr.bin/xlint/lint1/cgram.y Sat Jan 21 08:04:43 2023
@@ -1,5 +1,5 @@
%{
-/* $NetBSD: cgram.y,v 1.426 2023/01/15 00:05:38 rillig Exp $ */
+/* $NetBSD: cgram.y,v 1.427 2023/01/21 08:04:43 rillig Exp $ */
/*
* Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved.
@@ -35,7 +35,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID)
-__RCSID("$NetBSD: cgram.y,v 1.426 2023/01/15 00:05:38 rillig Exp $");
+__RCSID("$NetBSD: cgram.y,v 1.427 2023/01/21 08:04:43 rillig Exp $");
#endif
#include <limits.h>
@@ -850,7 +850,7 @@ notype_type_specifier: /* see C99 6.7.2
$$ = gettyp($1);
}
| T_TYPEOF T_LPAREN expression T_RPAREN { /* GCC extension */
- $$ = block_dup_type($3->tn_type);
+ $$ = $3 != NULL ? block_dup_type($3->tn_type) : gettyp(INT);
$$->t_typeof = true;
}
| struct_or_union_specifier {
