[PATCH] posix: Fix macro expansion producing 'defined' has undefined behavior
Adhemerval Zanella
adhemerval.zanella@linaro.org
Mon Aug 29 19:00:37 GMT 2022
The NEED_CHECK_SPEC is defined as:
#define NEED_CHECK_SPEC \
(!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
|| !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \
|| !defined _POSIX_V6_ILP32_OFF32 || !defined _POSIX_V6_ILP32_OFFBIG \
|| !defined _POSIX_V6_LP64_OFF64 || !defined _POSIX_V6_LPBIG_OFFBIG \
|| !defined _POSIX_V7_ILP32_OFF32 || !defined _POSIX_V7_ILP32_OFFBIG \
|| !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG)
Which is undefined behavior accordingly to C Standard (Preprocessing
directives, p4).
Checked on x86_64-linux-gnu.
---
sysdeps/posix/sysconf.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/sysdeps/posix/sysconf.c b/sysdeps/posix/sysconf.c
index f760bf4e2b..c29b70ad80 100644
--- a/sysdeps/posix/sysconf.c
+++ b/sysdeps/posix/sysconf.c
@@ -37,13 +37,17 @@
#define NEED_SPEC_ARRAY 0
#include <posix-conf-vars.h>
-#define NEED_CHECK_SPEC \
- (!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
+#if !defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
|| !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \
|| !defined _POSIX_V6_ILP32_OFF32 || !defined _POSIX_V6_ILP32_OFFBIG \
|| !defined _POSIX_V6_LP64_OFF64 || !defined _POSIX_V6_LPBIG_OFFBIG \
|| !defined _POSIX_V7_ILP32_OFF32 || !defined _POSIX_V7_ILP32_OFFBIG \
- || !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG)
+ || !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG
+# define NEED_CHECK_SPEC 1
+#else
+# define NEED_CHECK_SPEC 0
+#endif
+
#if NEED_CHECK_SPEC
static long int __sysconf_check_spec (const char *spec);
#endif
--
2.34.1
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