mirrors/haproxy
1
0
Fork 0
mirror of https://git.haproxy.org/git/haproxy.git/ synced 2025-09-23 14:51:27 +02:00
Code Issues Projects Releases Wiki Activity

BUILD: compiler: add a default definition for __has_attribute()

Browse Source 
It happens that gcc since 5.x has this macro which is only mentioned
once in the doc, associated with __builtin_has_attribute(). Clang had
it at least since 3.0. In addition it validates #ifdef when present,
so it's easy to detect it. Here we're providing a fallback to another
macro __has_attribute_<name> so that it's possible to define that macro
to the value 1 for older compilers when the attribute is supported.
This commit is contained in:
Willy Tarreau 2022-11-13 11:39:18 +01:00
parent 08e09f0b3c
commit 2b080f713f
1 changed files with 11 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
include/haproxy/compiler.h
View File

@ -49,6 +49,17 @@
#define ___equals_1(x, ...) ____equals_1(x, 0) #define ___equals_1(x, ...) ____equals_1(x, 0)
#define __equals_1(x) ___equals_1(comma_for_one ## x 1) #define __equals_1(x) ___equals_1(comma_for_one ## x 1)
/* gcc 5 and clang 3 brought __has_attribute(), which is not well documented in
* the case of gcc, but is convenient since handled at the preprocessor level.
* In both cases it's possible to test for __has_attribute() using ifdef. When
* not defined we remap this to the __has_attribute_<name> macro so that we'll
* later be able to implement on a per-compiler basis those which are missing,
* by defining __has_attribute_<name> to 1.
*/
#ifndef __has_attribute
#define __has_attribute(x) __equals_1(__has_attribute_ ## x)
#endif
#if !defined(__GNUC__) #if !defined(__GNUC__)
/* Some versions of glibc irresponsibly redefine __attribute__() to empty for /* Some versions of glibc irresponsibly redefine __attribute__() to empty for
* non-gcc compilers, and as such, silently break all constructors with other * non-gcc compilers, and as such, silently break all constructors with other