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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2023-08-06 13:27:27 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2023-08-06 21:09:52 +0000 |
| commit | 15876d9fd83fdfa7d541ea747eb40faeade975d2 (patch) | |
| tree | 2d44e379e0b709775dd26d457c06165ac0afe46f | |
| parent | 9ec7a595ed2c7631ef916d9f5818ccd5c5d327c8 (diff) | |
| download | src-15876d9fd83fdfa7d541ea747eb40faeade975d2.tar.gz src-15876d9fd83fdfa7d541ea747eb40faeade975d2.zip | |
sys/cdefs.h: fix for use __restrict in C++
Newlib shares large parts of <sys/cdefs.h> with FreeBSD and received
this bug report:
https://sourceware.org/pipermail/newlib/2023/020400.html
As an extension, GCC and clang offer C99-style restricted pointers in
C++ mode:
https://gcc.gnu.org/onlinedocs/gcc/Restricted-Pointers.html
We notice that this extension is broken when including newlib headers:
restricted pointers are treated as ordinary pointers.
We traced this to the following section of
newlib/libc/include/sys/cdefs.h:
/*
* GCC 2.95 provides `__restrict' as an extension to C90 to support the
* C99-specific `restrict' type qualifier. We happen to use `__restrict' as
* a way to define the `restrict' type qualifier without disturbing older
* software that is unaware of C99 keywords.
*/
#if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95)
#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901
#define __restrict
#else
#define __restrict restrict
#endif
#endif
While the GCC __restrict extension was indeed introduced in GCC 2.95, it
is not limited to this version; the extension is also not limited to
C90:
https://gcc.gnu.org/gcc-2.95/c++features.html
Rewrite the logic in the header so that __restrict is kept alone when
available.
PR: 272723
MFC after: 1 week
| -rw-r--r-- | sys/sys/cdefs.h | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h index 1de042339c3a..797460c08db8 100644 --- a/sys/sys/cdefs.h +++ b/sys/sys/cdefs.h @@ -403,17 +403,15 @@ #endif /* - * GCC 2.95 provides `__restrict' as an extension to C90 to support the - * C99-specific `restrict' type qualifier. We happen to use `__restrict' as - * a way to define the `restrict' type qualifier without disturbing older - * software that is unaware of C99 keywords. + * We use `__restrict' as a way to define the `restrict' type qualifier + * without disturbing older software that is unaware of C99 keywords. + * GCC also provides `__restrict' as an extension to support C99-style + * restricted pointers in other language modes. */ -#if !(__GNUC__ == 2 && __GNUC_MINOR__ == 95) -#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901 -#define __restrict -#else +#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901 #define __restrict restrict -#endif +#elif !__GNUC_PREREQ__(2, 95) +#define __restrict #endif /* |