+++ /dev/null
-# ===========================================================================
-# https://www.gnu.org/software/autoconf-archive/ax_gcc_func_attribute.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-# AX_GCC_FUNC_ATTRIBUTE(ATTRIBUTE)
-#
-# DESCRIPTION
-#
-# This macro checks if the compiler supports one of GCC's function
-# attributes; many other compilers also provide function attributes with
-# the same syntax. Compiler warnings are used to detect supported
-# attributes as unsupported ones are ignored by default so quieting
-# warnings when using this macro will yield false positives.
-#
-# The ATTRIBUTE parameter holds the name of the attribute to be checked.
-#
-# If ATTRIBUTE is supported define HAVE_FUNC_ATTRIBUTE_<ATTRIBUTE>.
-#
-# The macro caches its result in the ax_cv_have_func_attribute_<attribute>
-# variable.
-#
-# The macro currently supports the following function attributes:
-#
-# alias
-# aligned
-# alloc_size
-# always_inline
-# artificial
-# cold
-# const
-# constructor
-# constructor_priority for constructor attribute with priority
-# deprecated
-# destructor
-# dllexport
-# dllimport
-# error
-# externally_visible
-# fallthrough
-# flatten
-# format
-# format_arg
-# gnu_inline
-# hot
-# ifunc
-# leaf
-# malloc
-# noclone
-# noinline
-# nonnull
-# noreturn
-# nothrow
-# optimize
-# pure
-# sentinel
-# sentinel_position
-# unused
-# used
-# visibility
-# warning
-# warn_unused_result
-# weak
-# weakref
-#
-# Unsupported function attributes will be tested with a prototype
-# returning an int and not accepting any arguments and the result of the
-# check might be wrong or meaningless so use with care.
-#
-# LICENSE
-#
-# Copyright (c) 2013 Gabriele Svelto <gabriele.svelto@gmail.com>
-#
-# Copying and distribution of this file, with or without modification, are
-# permitted in any medium without royalty provided the copyright notice
-# and this notice are preserved. This file is offered as-is, without any
-# warranty.
-
-#serial 9
-
-AC_DEFUN([AX_GCC_FUNC_ATTRIBUTE], [
- AS_VAR_PUSHDEF([ac_var], [ax_cv_have_func_attribute_$1])
-
- AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
- AC_LINK_IFELSE([AC_LANG_PROGRAM([
- m4_case([$1],
- [alias], [
- int foo( void ) { return 0; }
- int bar( void ) __attribute__(($1("foo")));
- ],
- [aligned], [
- int foo( void ) __attribute__(($1(32)));
- ],
- [alloc_size], [
- void *foo(int a) __attribute__(($1(1)));
- ],
- [always_inline], [
- inline __attribute__(($1)) int foo( void ) { return 0; }
- ],
- [artificial], [
- inline __attribute__(($1)) int foo( void ) { return 0; }
- ],
- [cold], [
- int foo( void ) __attribute__(($1));
- ],
- [const], [
- int foo( void ) __attribute__(($1));
- ],
- [constructor_priority], [
- int foo( void ) __attribute__((__constructor__(65535/2)));
- ],
- [constructor], [
- int foo( void ) __attribute__(($1));
- ],
- [deprecated], [
- int foo( void ) __attribute__(($1("")));
- ],
- [destructor], [
- int foo( void ) __attribute__(($1));
- ],
- [dllexport], [
- __attribute__(($1)) int foo( void ) { return 0; }
- ],
- [dllimport], [
- int foo( void ) __attribute__(($1));
- ],
- [error], [
- int foo( void ) __attribute__(($1("")));
- ],
- [externally_visible], [
- int foo( void ) __attribute__(($1));
- ],
- [fallthrough], [
- int foo( void ) {switch (0) { case 1: __attribute__(($1)); case 2: break ; }};
- ],
- [flatten], [
- int foo( void ) __attribute__(($1));
- ],
- [format], [
- int foo(const char *p, ...) __attribute__(($1(printf, 1, 2)));
- ],
- [format_arg], [
- char *foo(const char *p) __attribute__(($1(1)));
- ],
- [gnu_inline], [
- inline __attribute__(($1)) int foo( void ) { return 0; }
- ],
- [hot], [
- int foo( void ) __attribute__(($1));
- ],
- [ifunc], [
- int my_foo( void ) { return 0; }
- static int (*resolve_foo(void))(void) { return my_foo; }
- int foo( void ) __attribute__(($1("resolve_foo")));
- ],
- [leaf], [
- __attribute__(($1)) int foo( void ) { return 0; }
- ],
- [malloc], [
- void *foo( void ) __attribute__(($1));
- ],
- [noclone], [
- int foo( void ) __attribute__(($1));
- ],
- [noinline], [
- __attribute__(($1)) int foo( void ) { return 0; }
- ],
- [nonnull], [
- int foo(char *p) __attribute__(($1(1)));
- ],
- [noreturn], [
- void foo( void ) __attribute__(($1));
- ],
- [nothrow], [
- int foo( void ) __attribute__(($1));
- ],
- [optimize], [
- __attribute__(($1(3))) int foo( void ) { return 0; }
- ],
- [pure], [
- int foo( void ) __attribute__(($1));
- ],
- [sentinel], [
- int foo(void *p, ...) __attribute__(($1));
- ],
- [sentinel_position], [
- int foo(void *p, ...) __attribute__(($1(1)));
- ],
- [returns_nonnull], [
- void *foo( void ) __attribute__(($1));
- ],
- [unused], [
- int foo( void ) __attribute__(($1));
- ],
- [used], [
- int foo( void ) __attribute__(($1));
- ],
- [visibility], [
- int foo_def( void ) __attribute__(($1("default")));
- int foo_hid( void ) __attribute__(($1("hidden")));
- int foo_int( void ) __attribute__(($1("internal")));
- int foo_pro( void ) __attribute__(($1("protected")));
- ],
- [warning], [
- int foo( void ) __attribute__(($1("")));
- ],
- [warn_unused_result], [
- int foo( void ) __attribute__(($1));
- ],
- [weak], [
- int foo( void ) __attribute__(($1));
- ],
- [weakref], [
- static int foo( void ) { return 0; }
- static int bar( void ) __attribute__(($1("foo")));
- ],
- [
- m4_warn([syntax], [Unsupported attribute $1, the test may fail])
- int foo( void ) __attribute__(($1));
- ]
- )], [])
- ],
- dnl GCC doesn't exit with an error if an unknown attribute is
- dnl provided but only outputs a warning, so accept the attribute
- dnl only if no warning were issued.
- [AS_IF([test -s conftest.err],
- [AS_VAR_SET([ac_var], [no])],
- [AS_VAR_SET([ac_var], [yes])])],
- [AS_VAR_SET([ac_var], [no])])
- ])
-
- AS_IF([test yes = AS_VAR_GET([ac_var])],
- [AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_FUNC_ATTRIBUTE_$1), 1,
- [Define to 1 if the system has the `$1' function attribute])], [])
-
- AS_VAR_POPDEF([ac_var])
-])
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