1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
# expatcfg-compiler-supports-visibility.m4 --
#
# SYNOPSIS
#
# EXPATCFG_COMPILER_SUPPORTS_VISIBILITY([ACTION-IF-YES],
# [ACTION-IF-NO])
#
# DESCRIPTION
#
# Check if the selected compiler supports the "visibility" attribute
# and set the variable "expatcfg_cv_compiler_supports_visibility"
# accordingly to "yes" or "no".
#
# In addition, execute ACTION-IF-YES or ACTION-IF-NO.
#
# LICENSE
#
# Copyright (c) 2018 The Expat Authors.
#
# 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.
AC_DEFUN([EXPATCFG_COMPILER_SUPPORTS_VISIBILITY],
[AC_CACHE_CHECK([whether compiler supports visibility],
[expatcfg_cv_compiler_supports_visibility],
[AS_VAR_SET([expatcfg_cv_compiler_supports_visibility],[no])
AS_VAR_COPY([OLDFLAGS],[CFLAGS])
AS_VAR_APPEND([CFLAGS],[" -fvisibility=hidden -Wall -Werror -Wno-unknown-warning-option"])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
void __attribute__((visibility("default"))) foo(void);
void foo(void) {}
]])],
[AS_VAR_SET([expatcfg_cv_compiler_supports_visibility],[yes])])
AS_VAR_COPY([CFLAGS],[OLDFLAGS])])
AS_IF([test "$expatcfg_cv_compiler_supports_visibility" = yes],[$1],[$2])])
# end of file
|
