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Diffstat (limited to 'gnulib/import/m4/environ.m4')
-rw-r--r-- | gnulib/import/m4/environ.m4 | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/gnulib/import/m4/environ.m4 b/gnulib/import/m4/environ.m4 new file mode 100644 index 0000000..9a0ea7e --- /dev/null +++ b/gnulib/import/m4/environ.m4 @@ -0,0 +1,47 @@ +# environ.m4 serial 6 +dnl Copyright (C) 2001-2004, 2006-2016 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_DEFUN_ONCE([gl_ENVIRON], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + dnl Persuade glibc <unistd.h> to declare environ. + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + + AC_CHECK_HEADERS_ONCE([unistd.h]) + gt_CHECK_VAR_DECL( + [#if HAVE_UNISTD_H + #include <unistd.h> + #endif + /* mingw, BeOS, Haiku declare environ in <stdlib.h>, not in <unistd.h>. */ + #include <stdlib.h> + ], + [environ]) + if test $gt_cv_var_environ_declaration != yes; then + HAVE_DECL_ENVIRON=0 + fi +]) + +# Check if a variable is properly declared. +# gt_CHECK_VAR_DECL(includes,variable) +AC_DEFUN([gt_CHECK_VAR_DECL], +[ + define([gt_cv_var], [gt_cv_var_]$2[_declaration]) + AC_MSG_CHECKING([if $2 is properly declared]) + AC_CACHE_VAL([gt_cv_var], [ + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[$1 + extern struct { int foo; } $2;]], + [[$2.foo = 1;]])], + [gt_cv_var=no], + [gt_cv_var=yes])]) + AC_MSG_RESULT([$gt_cv_var]) + if test $gt_cv_var = yes; then + AC_DEFINE([HAVE_]m4_translit($2, [a-z], [A-Z])[_DECL], 1, + [Define if you have the declaration of $2.]) + fi + undefine([gt_cv_var]) +]) |