| Haibo Huang | fd5e81a | 2019-06-20 12:09:36 -0700 | [diff] [blame] | 1 | # expatcfg-compiler-supports-visibility.m4 -- |
| 2 | # |
| 3 | # SYNOPSIS |
| 4 | # |
| 5 | # EXPATCFG_COMPILER_SUPPORTS_VISIBILITY([ACTION-IF-YES], |
| 6 | # [ACTION-IF-NO]) |
| 7 | # |
| 8 | # DESCRIPTION |
| 9 | # |
| 10 | # Check if the selected compiler supports the "visibility" attribute |
| 11 | # and set the variable "expatcfg_cv_compiler_supports_visibility" |
| 12 | # accordingly to "yes" or "no". |
| 13 | # |
| 14 | # In addition, execute ACTION-IF-YES or ACTION-IF-NO. |
| 15 | # |
| 16 | # LICENSE |
| 17 | # |
| 18 | # Copyright (c) 2018 The Expat Authors. |
| 19 | # |
| 20 | # Copying and distribution of this file, with or without modification, |
| 21 | # are permitted in any medium without royalty provided the copyright |
| 22 | # notice and this notice are preserved. This file is offered as-is, |
| 23 | # without any warranty. |
| 24 | |
| 25 | AC_DEFUN([EXPATCFG_COMPILER_SUPPORTS_VISIBILITY], |
| 26 | [AC_CACHE_CHECK([whether compiler supports visibility], |
| 27 | [expatcfg_cv_compiler_supports_visibility], |
| 28 | [AS_VAR_SET([expatcfg_cv_compiler_supports_visibility],[no]) |
| 29 | AS_VAR_COPY([OLDFLAGS],[CFLAGS]) |
| 30 | AS_VAR_APPEND([CFLAGS],[" -fvisibility=hidden -Wall -Werror -Wno-unknown-warning-option"]) |
| 31 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ |
| 32 | void __attribute__((visibility("default"))) foo(void); |
| 33 | void foo(void) {} |
| 34 | ]])], |
| 35 | [AS_VAR_SET([expatcfg_cv_compiler_supports_visibility],[yes])]) |
| 36 | AS_VAR_COPY([CFLAGS],[OLDFLAGS])]) |
| 37 | AS_IF([test "$expatcfg_cv_compiler_supports_visibility" = yes],[$1],[$2])]) |
| 38 | |
| 39 | # end of file |