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| author | Paul Eggert <eggert@cs.ucla.edu> | 2023-02-07 20:37:09 -0800 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2023-02-07 20:37:34 -0800 |
| commit | 97f54920a3c2bd9a536ef8c1cb7667584bd84eaf (patch) | |
| tree | af45b01ac9a437a9449ebbad9c2175e4fb8b587c /m4 | |
| parent | 7a5061a0527b9fcaeedf48e8f5056dd80e77aa98 (diff) | |
| download | gnulib-97f54920a3c2bd9a536ef8c1cb7667584bd84eaf.tar.gz | |
nullptr: test for compilers at autoconf-time
* m4/nullptr.m4 (gl_NULLPTR): Test for C and C++ compiler usage at
autoconf-time. This should work better than testing at
configure-time. Also, push and pop languages so we check the
proper compiler.
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/nullptr.m4 | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/m4/nullptr.m4 b/m4/nullptr.m4 index dda7646906..a0b438be94 100644 --- a/m4/nullptr.m4 +++ b/m4/nullptr.m4 @@ -7,22 +7,32 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_NULLPTR], [ - AS_IF([test ${CC+set}], - [AC_CACHE_CHECK([for C nullptr], [gl_cv_c_nullptr], + m4_provide_if([AC_PROG_CC], + [AC_LANG_PUSH([C]) + AC_CACHE_CHECK([for C nullptr], [gl_cv_c_nullptr], [AC_COMPILE_IFELSE( [AC_LANG_SOURCE([[int *p = nullptr;]])], [gl_cv_c_nullptr=yes], - [gl_cv_c_nullptr=no])])]) - if test "$gl_cv_c_nullptr" = yes; then - AC_DEFINE([HAVE_C_NULLPTR], [1], [Define to 1 if C nullptr works.]) + [gl_cv_c_nullptr=no])]) + gl_c_nullptr=$gl_cv_c_nullptr + AC_LANG_POP([C])], + [gl_c_nullptr=no]) + if test "$gl_c_nullptr" = yes; then + AC_DEFINE([HAVE_C_NULLPTR], [1], + [Define to 1 if C nullptr is known to work.]) fi - AS_IF([test ${CXX+set}], - [AC_CACHE_CHECK([for C++ nullptr], [gl_cv_cxx_nullptr], + + m4_provide_if([AC_PROG_CXX], + [AC_LANG_PUSH([C++]) + AC_CACHE_CHECK([for C++ nullptr], [gl_cv_cxx_nullptr], [AC_COMPILE_IFELSE( [AC_LANG_SOURCE([[int *p = nullptr;]])], [gl_cv_cxx_nullptr=yes], - [gl_cv_cxx_nullptr=no])])]) - if test "$gl_cv_cxx_nullptr" = yes; then + [gl_cv_cxx_nullptr=no])]) + gl_cxx_nullptr=$gl_cv_cxx_nullptr + AC_LANG_POP([C++])], + [gl_cxx_nullptr=no]) + if test "$gl_cxx_nullptr" = yes; then AC_DEFINE([HAVE_CXX_NULLPTR], [1], [Define to 1 if C++ nullptr works.]) fi ]) |