New upstream version 1.1upstream/1.1

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
     ])