From 3029b659e89caa79b6860c3bbe8cbc18b53af678 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Thu, 22 Jun 2017 15:06:58 +0200 Subject: Enable compiler warnings This patch borrows the compiler.m4 script from util-linux to check for compiler support of a number of warning flags and sets them if they are supported. Signed-off-by: David Oberhollenzer --- m4/compiler.m4 | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 m4/compiler.m4 (limited to 'm4') diff --git a/m4/compiler.m4 b/m4/compiler.m4 new file mode 100644 index 0000000..058c73f --- /dev/null +++ b/m4/compiler.m4 @@ -0,0 +1,40 @@ +dnl Copyright (C) 2008-2011 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. + +dnl From Simon Josefsson +dnl -- derivated from coreutils m4/warnings.m4 + +# UL_AS_VAR_APPEND(VAR, VALUE) +# ---------------------------- +# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it. +m4_ifdef([AS_VAR_APPEND], +[m4_copy([AS_VAR_APPEND], [UL_AS_VAR_APPEND])], +[m4_define([UL_AS_VAR_APPEND], +[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])]) + +# UL_ADD_WARN(COMPILER_OPTION [, VARNAME]) +# ------------------------ +# Adds parameter to WARN_CFLAGS (or to $VARNAME) if the compiler supports it. +AC_DEFUN([UL_WARN_ADD], [ + m4_define([warnvarname], m4_default([$2],WARN_CFLAGS)) + AS_VAR_PUSHDEF([ul_Warn], [ul_cv_warn_$1])dnl + AC_CACHE_CHECK([whether compiler handles $1], m4_defn([ul_Warn]), [ + # store AC_LANG_WERROR status, then turn it on + save_ac_[]_AC_LANG_ABBREV[]_werror_flag="${ac_[]_AC_LANG_ABBREV[]_werror_flag}" + AC_LANG_WERROR + + ul_save_CPPFLAGS="$CPPFLAGS" + CPPFLAGS="-Werror ${CPPFLAGS} $1" + AC_PREPROC_IFELSE([AC_LANG_PROGRAM([])], + [AS_VAR_SET(ul_Warn, [yes])], + [AS_VAR_SET(ul_Warn, [no])]) + # restore AC_LANG_WERROR + ac_[]_AC_LANG_ABBREV[]_werror_flag="${save_ac_[]_AC_LANG_ABBREV[]_werror_flag}" + + CPPFLAGS="$ul_save_CPPFLAGS" + ]) + AS_VAR_IF(ul_Warn, [yes], [UL_AS_VAR_APPEND(warnvarname, [" $1"])]) +]) + -- cgit v1.2.3