From: Jim Meyering <jim@meyering.net>
To: libc-alpha@sourceware.org
Cc: Roland McGrath <roland@hack.frob.com>
Subject: [PATCH] assert.h: allow gcc to detect assert(a = 1) errors
Date: Wed, 16 Jul 2014 19:12:00 -0000 [thread overview]
Message-ID: <1405537923-28692-1-git-send-email-jim@meyering.net> (raw)
From: Jim Meyering <meyering@fb.com>
* assert/assert.h (assert): Rewrite assert's definition so that
a s/==/=/ typo, e.g., assert(errno = ENOENT) is not hidden from
gcc's -Wparentheses by the parentheses added by assert.
The new definition uses "if (expr) ; else __assert_fail...", so
gcc -Wall will now detect that type of error in an assert, too.
---
assert/assert.h | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/assert/assert.h b/assert/assert.h
index 2661391..ffcf60c 100644
--- a/assert/assert.h
+++ b/assert/assert.h
@@ -82,10 +82,23 @@ extern void __assert (const char *__assertion, const char *__file, int __line)
__END_DECLS
-# define assert(expr) \
- ((expr) \
- ? __ASSERT_VOID_CAST (0) \
- : __assert_fail (__STRING(expr), __FILE__, __LINE__, __ASSERT_FUNCTION))
+/* When possible, define assert so that it does not add extra
+ parentheses around EXPR. Otherwise, those added parentheses would
+ suppress warnings we'd expect to be detected by gcc's -Wparentheses. */
+# if !defined __GNUC__ || defined __STRICT_ANSI__
+# define assert(expr) \
+ ((expr) \
+ ? __ASSERT_VOID_CAST (0) \
+ : __assert_fail (__STRING(expr), __FILE__, __LINE__, __ASSERT_FUNCTION))
+# else
+# define assert(expr) \
+ ({ \
+ if (expr) \
+ ; /* empty */ \
+ else \
+ __assert_fail (__STRING(expr), __FILE__, __LINE__, __ASSERT_FUNCTION);\
+ })
+# endif
# ifdef __USE_GNU
# define assert_perror(errnum) \
--
2.0.1
next reply other threads:[~2014-07-16 19:12 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-16 19:12 Jim Meyering [this message]
2014-07-16 20:15 ` Roland McGrath
2014-07-16 20:44 ` Jim Meyering
2016-11-24 2:22 ` Jim Meyering
2016-11-24 2:59 ` Zack Weinberg
2016-11-24 13:13 ` Joseph Myers
2016-11-26 6:36 ` Jim Meyering
2016-11-24 7:36 ` Florian Weimer
2016-11-26 6:15 ` Jim Meyering
2016-12-09 3:21 ` Jim Meyering
2016-12-14 5:28 ` Jim Meyering
2016-12-14 9:13 ` Florian Weimer
2016-12-15 0:25 ` Jim Meyering
2016-12-16 12:15 ` Florian Weimer
2016-12-18 9:53 ` Jim Meyering
2016-12-27 17:47 ` Andreas Schwab
2016-12-28 12:50 ` Florian Weimer
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