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-rw-r--r--m4/warn-on-use.m462
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diff --git a/m4/warn-on-use.m4 b/m4/warn-on-use.m4
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+# warn-on-use.m4 serial 10
+dnl Copyright (C) 2010-2023 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.
+
+# gl_WARN_ON_USE_PREPARE(INCLUDES, NAMES)
+# ---------------------------------------
+# If the module 'posixcheck' is in use:
+#
+# For each whitespace-separated element in the list of NAMES, define
+# HAVE_RAW_DECL_name if the function has a declaration among INCLUDES
+# even after being undefined as a macro.
+#
+# See warn-on-use.h for some hints on how to poison function names, as
+# well as ideas on poisoning global variables and macros. NAMES may
+# include global variables, but remember that only functions work with
+# _GL_WARN_ON_USE. Typically, INCLUDES only needs to list a single
+# header, but if the replacement header pulls in other headers because
+# some systems declare functions in the wrong header, then INCLUDES
+# should do likewise.
+#
+# It is generally safe to assume declarations for functions declared
+# in the intersection of C89 and C11 (such as printf) without
+# needing gl_WARN_ON_USE_PREPARE.
+AC_DEFUN([gl_WARN_ON_USE_PREPARE],
+[
+ m4_ifdef([gl_POSIXCHECK],
+ [m4_foreach_w([gl_decl], [$2],
+ [AH_TEMPLATE([HAVE_RAW_DECL_]AS_TR_CPP(m4_defn([gl_decl])),
+ [Define to 1 if ]m4_defn([gl_decl])[ is declared even after
+ 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 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
+ ])
+])