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* [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
@ 2013-01-23 19:26 rjarrett at mathworks dot com
2013-01-23 20:48 ` [Bug c/56086] " joseph at codesourcery dot com
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: rjarrett at mathworks dot com @ 2013-01-23 19:26 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
Bug #: 56086
Summary: when compiling C code with -std=gnu99 macro
__STDC_UTF_16__ is defined
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: rjarrett@mathworks.com
Created attachment 29255
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29255
sample program
The macro __STDC_UTF_16__ is unexpectedly defined when compiling C code using
gcc 4.7.2 (also present in gcc 4.7.1)
This is a regression from gcc 4.5.3. (also gcc 4.4.6)
compilation line:
gcc -c -std=gnu99 gcc47_stdc_utf_16.c
expected result: no output
actual result:
gcc47_stdc_utf_16.c:3:2: warning: #warning __STDC_UTF_16__ defined [-Wcpp]
use case was in a header file used for both C and C++ compilation that
contained
#if defined(__STDC_UTF_16__)
...
#endif
workaround:
use :#if (__cplusplus && defined(__STDC_UTF_16__)) in place of
#if defined(__STDC_UTF_16__)
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/56086] when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
@ 2013-01-23 20:48 ` joseph at codesourcery dot com
2013-01-27 16:12 ` rjarrett at mathworks dot com
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: joseph at codesourcery dot com @ 2013-01-23 20:48 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2013-01-23 20:47:49 UTC ---
Why do you think this is a bug? GCC meets the semantics of that macro
(that char16_t values are UTF-16 encoded), and gnu99 mode enables u""
strings.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/56086] when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
2013-01-23 20:48 ` [Bug c/56086] " joseph at codesourcery dot com
@ 2013-01-27 16:12 ` rjarrett at mathworks dot com
2013-01-27 16:14 ` rjarrett at mathworks dot com
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: rjarrett at mathworks dot com @ 2013-01-27 16:12 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
--- Comment #2 from Roger Jarrett <rjarrett at mathworks dot com> 2013-01-27 16:12:09 UTC ---
Created attachment 29285
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29285
example program to compile
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/56086] when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
2013-01-23 20:48 ` [Bug c/56086] " joseph at codesourcery dot com
2013-01-27 16:12 ` rjarrett at mathworks dot com
@ 2013-01-27 16:14 ` rjarrett at mathworks dot com
2013-01-28 3:43 ` joseph at codesourcery dot com
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: rjarrett at mathworks dot com @ 2013-01-27 16:14 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
--- Comment #3 from Roger Jarrett <rjarrett at mathworks dot com> 2013-01-27 16:13:48 UTC ---
The macro __STDC_UTF_16__ is being used to guard the following typedef
typedef char16_t CHAR16_T;
compiling the program (attached program t2.c)
typedef char16_t fred;
int main() {
}
with gcc 4.7.1 or 4.7.2 results in a compilation error: gcc -std=gnu99 t2.c
t2.c:1:1: error: unknown type name 'char16_t'
However, it succeeds as expected when compiled with g++ -std=c++11 t2.c
What am I missing here ?
--Roger
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/56086] when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
` (2 preceding siblings ...)
2013-01-27 16:14 ` rjarrett at mathworks dot com
@ 2013-01-28 3:43 ` joseph at codesourcery dot com
2013-01-28 8:29 ` jakub at gcc dot gnu.org
2013-01-29 17:43 ` jason at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: joseph at codesourcery dot com @ 2013-01-28 3:43 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2013-01-28 03:43:31 UTC ---
For C, char16_t and char32_t are typedefs in <uchar.h> (a header provided
by the C library, not by GCC), *not* built-in types, and __STDC_UTF_16__
is a built-in macro.
For C++, char16_t and char32_t are built-in types that don't need a header
to use them, and __STDC_UTF_16__ is defined in <cuchar> rather than
built-in (I don't know if any change may have resulted from Jason raising
the issue of the difference from C regarding that macro as per
<http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01524.html>).
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/56086] when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
` (3 preceding siblings ...)
2013-01-28 3:43 ` joseph at codesourcery dot com
@ 2013-01-28 8:29 ` jakub at gcc dot gnu.org
2013-01-29 17:43 ` jason at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: jakub at gcc dot gnu.org @ 2013-01-28 8:29 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org,
| |jason at gcc dot gnu.org
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-28 08:28:40 UTC ---
Let's CC Jason on this.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c/56086] when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined
2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
` (4 preceding siblings ...)
2013-01-28 8:29 ` jakub at gcc dot gnu.org
@ 2013-01-29 17:43 ` jason at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: jason at gcc dot gnu.org @ 2013-01-29 17:43 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> 2013-01-29 17:43:23 UTC ---
(In reply to comment #3)
> The macro __STDC_UTF_16__ is being used to guard the following typedef
> typedef char16_t CHAR16_T;
This doesn't work. The macro does not indicate that char16_t is declared;
rather, it indicates that values of char16_t are UTF-16 encoded. The compiler
is following the standard.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-01-29 17:43 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2013-01-23 19:26 [Bug c/56086] New: when compiling C code with -std=gnu99 macro __STDC_UTF_16__ is defined rjarrett at mathworks dot com
2013-01-23 20:48 ` [Bug c/56086] " joseph at codesourcery dot com
2013-01-27 16:12 ` rjarrett at mathworks dot com
2013-01-27 16:14 ` rjarrett at mathworks dot com
2013-01-28 3:43 ` joseph at codesourcery dot com
2013-01-28 8:29 ` jakub at gcc dot gnu.org
2013-01-29 17:43 ` jason at gcc dot gnu.org
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