[committed] Use __builtin_FILE instead of __FILE__ in assert in C++.
Commit Message
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", ...)
---
assert/assert.h | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
Comments
On Feb 10 2023, Paul Pluzhnikov via Libc-alpha wrote:
> +# if !defined(__ASSERT_FILE)
Please remove the extra parens.
On Fri, Feb 10, 2023 at 9:01 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Feb 10 2023, Paul Pluzhnikov via Libc-alpha wrote:
>
> > +# if !defined(__ASSERT_FILE)
>
> Please remove the extra parens.
Done.
I was able to push amended patch (since there were no newer commits).
Is that what I should have done?
Thanks,
On Fri, 10 Feb 2023, Paul Pluzhnikov via Libc-alpha wrote:
> I was able to push amended patch (since there were no newer commits).
> Is that what I should have done?
No, you should never do non-fast-forward pushes to master or other shared
branches. Carlos, could you investigate why the allow-non-fast-forward =
(?!master|release.*) setting wasn't working to prevent such a push? Is
the setting being matched against full ref names and so considering
refs/heads/master to match (?!master|release.*)?
On 2/10/23 16:56, Joseph Myers wrote:
> On Fri, 10 Feb 2023, Paul Pluzhnikov via Libc-alpha wrote:
>
>> I was able to push amended patch (since there were no newer commits).
>> Is that what I should have done?
>
> No, you should never do non-fast-forward pushes to master or other shared
> branches. Carlos, could you investigate why the allow-non-fast-forward =
> (?!master|release.*) setting wasn't working to prevent such a push? Is
> the setting being matched against full ref names and so considering
> refs/heads/master to match (?!master|release.*)?
>
Yes, I'll look at this. This shouldn't be allowed.
@@ -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) \