--- /dev/null
+# ===========================================================================
+# http://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
+# flatten
+# format
+# format_arg
+# gnu_inline
+# hot
+# ifunc
+# leaf
+# malloc
+# noclone
+# noinline
+# nonnull
+# noreturn
+# nothrow
+# optimize
+# pure
+# unused
+# used
+# visibility
+# warning
+# warn_unused_result
+# weak
+# weakref
+#
+# Unsuppored 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 3
+
+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));
+ ],
+ [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));
+ ],
+ [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])
+])
projects / thirdparty / lldpd.git / commitdiff
