+++ /dev/null
-# ===========================================================================
-# http://www.gnu.org/software/autoconf-archive/ax_gcc_var_attribute.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-# AX_GCC_VAR_ATTRIBUTE(ATTRIBUTE)
-#
-# DESCRIPTION
-#
-# This macro checks if the compiler supports one of GCC's variable
-# attributes; many other compilers also provide variable 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_VAR_ATTRIBUTE_<ATTRIBUTE>.
-#
-# The macro caches its result in the ax_cv_have_var_attribute_<attribute>
-# variable.
-#
-# The macro currently supports the following variable attributes:
-#
-# aligned
-# cleanup
-# common
-# nocommon
-# deprecated
-# mode
-# packed
-# tls_model
-# unused
-# used
-# vector_size
-# weak
-# dllimport
-# dllexport
-# init_priority
-#
-# Unsupported variable attributes will be tested against a global integer
-# variable and without any arguments given to the attribute itself; the
-# result of this 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_VAR_ATTRIBUTE], [
- AS_VAR_PUSHDEF([ac_var], [ax_cv_have_var_attribute_$1])
-
- AC_CACHE_CHECK([for __attribute__(($1))], [ac_var], [
- AC_LINK_IFELSE([AC_LANG_PROGRAM([
- m4_case([$1],
- [aligned], [
- int foo __attribute__(($1(32)));
- ],
- [cleanup], [
- int bar(int *t) { return *t; };
- ],
- [common], [
- int foo __attribute__(($1));
- ],
- [nocommon], [
- int foo __attribute__(($1));
- ],
- [deprecated], [
- int foo __attribute__(($1)) = 0;
- ],
- [mode], [
- long foo __attribute__(($1(word)));
- ],
- [packed], [
- struct bar {
- int baz __attribute__(($1));
- };
- ],
- [tls_model], [
- __thread int bar1 __attribute__(($1("global-dynamic")));
- __thread int bar2 __attribute__(($1("local-dynamic")));
- __thread int bar3 __attribute__(($1("initial-exec")));
- __thread int bar4 __attribute__(($1("local-exec")));
- ],
- [unused], [
- int foo __attribute__(($1));
- ],
- [used], [
- int foo __attribute__(($1));
- ],
- [vector_size], [
- int foo __attribute__(($1(16)));
- ],
- [weak], [
- int foo __attribute__(($1));
- ],
- [dllimport], [
- int foo __attribute__(($1));
- ],
- [dllexport], [
- int foo __attribute__(($1));
- ],
- [init_priority], [
- struct bar { bar() {} ~bar() {} };
- bar b __attribute__(($1(65535/2)));
- ],
- [
- m4_warn([syntax], [Unsupported attribute $1, the test may fail])
- int foo __attribute__(($1));
- ]
- )], [
- m4_case([$1],
- [cleanup], [
- int foo __attribute__(($1(bar))) = 0;
- foo = foo + 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_VAR_ATTRIBUTE_$1), 1,
- [Define to 1 if the system has the `$1' variable attribute])], [])
-
- AS_VAR_POPDEF([ac_var])
-])