public inbox for glibc-cvs@sourceware.org
help / color / mirror / Atom feed
* [glibc] Use __builtin_FILE instead of __FILE__ in assert in C++.
@ 2023-02-10 17:13 Paul Pluzhnikov
0 siblings, 0 replies; 3+ messages in thread
From: Paul Pluzhnikov @ 2023-02-10 17:13 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e42ec822190056895e55e5140ce2304e67e34445
commit e42ec822190056895e55e5140ce2304e67e34445
Author: Paul Pluzhnikov <ppluzhnikov@google.com>
Date: Fri Feb 10 16:14:30 2023 +0000
Use __builtin_FILE instead of __FILE__ in assert in C++.
Likewise use __builtin_LINE instead of __LINE__.
When building C++, inline functions are required to have the exact same
sequence of tokens in every translation unit. But __FILE__ token, when
used in a header file, does not necessarily expand to the exact same
string literal, and that may cause compilation failure when C++ modules
are being used. (It would also cause unpredictable output on assertion
failure at runtime, but this rarely matters in practice.)
For example, given the following sources:
// a.h
#include <assert.h>
inline void fn () { assert (0); }
// a.cc
#include "a.h"
// b.cc
#include "foo/../a.h"
preprocessing a.cc will yield a call to __assert_fail("0", "a.h", ...)
but b.cc will yield __assert_fail("0", "foo/../a.h", ...)
Diff:
---
assert/assert.h | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/assert/assert.h b/assert/assert.h
index 72209bc5e7..62670e4bbb 100644
--- a/assert/assert.h
+++ b/assert/assert.h
@@ -86,10 +86,21 @@ __END_DECLS
parentheses around EXPR. Otherwise, those added parentheses would
suppress warnings we'd expect to be detected by gcc's -Wparentheses. */
# if defined __cplusplus
+# if defined __has_builtin
+# if __has_builtin (__builtin_FILE)
+# define __ASSERT_FILE __builtin_FILE ()
+# define __ASSERT_LINE __builtin_LINE ()
+# endif
+# endif
+# if !defined __ASSERT_FILE
+# define __ASSERT_FILE __FILE__
+# define __ASSERT_LINE __LINE__
+# endif
# define assert(expr) \
(static_cast <bool> (expr) \
? void (0) \
- : __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
+ : __assert_fail (#expr, __ASSERT_FILE, __ASSERT_LINE, \
+ __ASSERT_FUNCTION))
# elif !defined __GNUC__ || defined __STRICT_ANSI__
# define assert(expr) \
((expr) \
^ permalink raw reply [flat|nested] 3+ messages in thread
* [glibc] Use __builtin_FILE instead of __FILE__ in assert in C++.
@ 2023-02-10 17:13 Paul Pluzhnikov
0 siblings, 0 replies; 3+ messages in thread
From: Paul Pluzhnikov @ 2023-02-10 17:13 UTC (permalink / raw)
To: glibc-cvs
The branch 'master' was updated to point to:
e42ec82219... Use __builtin_FILE instead of __FILE__ in assert in C++.
It previously pointed to:
8757659b3c... Use __builtin_FILE instead of __FILE__ in assert in C++.
Diff:
!!! WARNING: THE FOLLOWING COMMITS ARE NO LONGER ACCESSIBLE (LOST):
-------------------------------------------------------------------
8757659... Use __builtin_FILE instead of __FILE__ in assert in C++.
Summary of changes (added commits):
-----------------------------------
e42ec82... Use __builtin_FILE instead of __FILE__ in assert in C++.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [glibc] Use __builtin_FILE instead of __FILE__ in assert in C++.
@ 2023-02-10 16:25 Paul Pluzhnikov
0 siblings, 0 replies; 3+ messages in thread
From: Paul Pluzhnikov @ 2023-02-10 16:25 UTC (permalink / raw)
To: glibc-cvs
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8757659b3cee57c1defee7772c3ee687d310b076
commit 8757659b3cee57c1defee7772c3ee687d310b076
Author: Paul Pluzhnikov <ppluzhnikov@google.com>
Date: Fri Feb 10 16:14:30 2023 +0000
Use __builtin_FILE instead of __FILE__ in assert in C++.
Likewise use __builtin_LINE instead of __LINE__.
When building C++, inline functions are required to have the exact same
sequence of tokens in every translation unit. But __FILE__ token, when
used in a header file, does not necessarily expand to the exact same
string literal, and that may cause compilation failure when C++ modules
are being used. (It would also cause unpredictable output on assertion
failure at runtime, but this rarely matters in practice.)
For example, given the following sources:
// a.h
#include <assert.h>
inline void fn () { assert (0); }
// a.cc
#include "a.h"
// b.cc
#include "foo/../a.h"
preprocessing a.cc will yield a call to __assert_fail("0", "a.h", ...)
but b.cc will yield __assert_fail("0", "foo/../a.h", ...)
Diff:
---
assert/assert.h | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/assert/assert.h b/assert/assert.h
index 72209bc5e7..63197b819c 100644
--- a/assert/assert.h
+++ b/assert/assert.h
@@ -86,10 +86,21 @@ __END_DECLS
parentheses around EXPR. Otherwise, those added parentheses would
suppress warnings we'd expect to be detected by gcc's -Wparentheses. */
# if defined __cplusplus
+# if defined __has_builtin
+# if __has_builtin (__builtin_FILE)
+# define __ASSERT_FILE __builtin_FILE ()
+# define __ASSERT_LINE __builtin_LINE ()
+# endif
+# endif
+# if !defined(__ASSERT_FILE)
+# define __ASSERT_FILE __FILE__
+# define __ASSERT_LINE __LINE__
+# endif
# define assert(expr) \
(static_cast <bool> (expr) \
? void (0) \
- : __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION))
+ : __assert_fail (#expr, __ASSERT_FILE, __ASSERT_LINE, \
+ __ASSERT_FUNCTION))
# elif !defined __GNUC__ || defined __STRICT_ANSI__
# define assert(expr) \
((expr) \
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-02-10 17:13 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-10 17:13 [glibc] Use __builtin_FILE instead of __FILE__ in assert in C++ Paul Pluzhnikov
-- strict thread matches above, loose matches on Subject: below --
2023-02-10 17:13 Paul Pluzhnikov
2023-02-10 16:25 Paul Pluzhnikov
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).