autoconf: import gcc function attribute check macro

Import Gabriele Svelto's AC_GCC_FUNC_ATTRIBUTE autoconf macro to check for
GCC-style function attributes.  This macro is part of the GNU Autoconf
Archive[1]. The imported file is distributed under an all-permissive license.

[1] https://www.gnu.org/software/autoconf-archive/

Change-Id: I64ccd00717fa9606a26aeeeea9030f4fb4877cf8
Reviewed-on: https://gerrit.openafs.org/12962
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
This commit is contained in:
Michael Meffie 2018-03-16 20:41:35 -04:00 committed by Benjamin Kaduk
parent 0da5ac4d9f
commit b818854f19
2 changed files with 250 additions and 0 deletions

12
LICENSE
View File

@ -415,3 +415,15 @@ src/cf/lib-pathname.m4 are covered by the following license:
THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
====================================================
The file src/cf/ax_gcc_func_attribute.m4 covered by
the following 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.

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@ -0,0 +1,238 @@
# ===========================================================================
# 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])
])