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-rw-r--r--gnulib-m4/warn-on-use.m421
1 files changed, 17 insertions, 4 deletions
diff --git a/gnulib-m4/warn-on-use.m4 b/gnulib-m4/warn-on-use.m4
index d43355ab..a81731f3 100644
--- a/gnulib-m4/warn-on-use.m4
+++ b/gnulib-m4/warn-on-use.m4
@@ -1,4 +1,4 @@
-# warn-on-use.m4 serial 9
+# warn-on-use.m4 serial 10
dnl Copyright (C) 2010-2022 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -32,17 +32,30 @@ AC_DEFUN([gl_WARN_ON_USE_PREPARE],
undefining macros.])])dnl
for gl_func in m4_flatten([$2]); do
AS_VAR_PUSHDEF([gl_Symbol], [gl_cv_have_raw_decl_$gl_func])dnl
+ dnl As a workaround to implicit built-in function declarations in
+ dnl clang (e.g. strndup), reference ac_compile_for_check_decl instead
+ dnl of ac_compile. If, for whatever reason, the override of AC_PROG_CC
+ dnl in zzgnulib.m4 is inactive, use the original ac_compile.
+ ac_save_ac_compile="$ac_compile"
+ if test -n "$ac_compile_for_check_decl"; then
+ ac_compile="$ac_compile_for_check_decl"
+ fi
AC_CACHE_CHECK([whether $gl_func is declared without a macro],
[gl_Symbol],
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$1],
[[#undef $gl_func
(void) $gl_func;]])],
[AS_VAR_SET([gl_Symbol], [yes])], [AS_VAR_SET([gl_Symbol], [no])])])
+ ac_compile="$ac_save_ac_compile"
AS_VAR_IF([gl_Symbol], [yes],
[AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_RAW_DECL_$gl_func]), [1])
- dnl shortcut - if the raw declaration exists, then set a cache
- dnl variable to allow skipping any later AC_CHECK_DECL efforts
- eval ac_cv_have_decl_$gl_func=yes])
+ dnl Shortcut for an AC_CHECK_DECL invocation that may come later:
+ dnl If the raw declaration exists with the given includes, then
+ dnl AC_CHECK_DECL with its many includes would see it as well.
+ dnl So, set a cache variable to allow skipping any later
+ dnl AC_CHECK_DECL invocation for $gl_func.
+ eval "ac_cv_have_decl_$gl_func=yes"
+ ])
AS_VAR_POPDEF([gl_Symbol])dnl
done
])