From a680d46edf747ec17456b6b8e69c95bc4e4407cb Mon Sep 17 00:00:00 2001 From: Pavel Roskin Date: Tue, 21 Jun 2016 16:30:17 -0700 Subject: Use -Wwrite-strings compiler flag if supported, add required macros String literals are const in C++. Using this warnings moves us closer to the stated goal of C++ compatibility, makes the code cleaner and lets compilers optimize the code better. Add m4/ax_append_compile_flags.m4 from Autoconf Archives for the AX_APPEND_COMPILE_FLAGS macro and m4/ax_check_compile_flag.m4 as its dependency. --- m4/ax_append_compile_flags.m4 | 67 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 m4/ax_append_compile_flags.m4 (limited to 'm4/ax_append_compile_flags.m4') diff --git a/m4/ax_append_compile_flags.m4 b/m4/ax_append_compile_flags.m4 new file mode 100644 index 00000000..2bb27ef2 --- /dev/null +++ b/m4/ax_append_compile_flags.m4 @@ -0,0 +1,67 @@ +# =========================================================================== +# http://www.gnu.org/software/autoconf-archive/ax_append_compile_flags.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_APPEND_COMPILE_FLAGS([FLAG1 FLAG2 ...], [FLAGS-VARIABLE], [EXTRA-FLAGS], [INPUT]) +# +# DESCRIPTION +# +# For every FLAG1, FLAG2 it is checked whether the compiler works with the +# flag. If it does, the flag is added FLAGS-VARIABLE +# +# If FLAGS-VARIABLE is not specified, the current language's flags (e.g. +# CFLAGS) is used. During the check the flag is always added to the +# current language's flags. +# +# If EXTRA-FLAGS is defined, it is added to the current language's default +# flags (e.g. CFLAGS) when the check is done. The check is thus made with +# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to +# force the compiler to issue an error when a bad flag is given. +# +# INPUT gives an alternative input source to AC_COMPILE_IFELSE. +# +# NOTE: This macro depends on the AX_APPEND_FLAG and +# AX_CHECK_COMPILE_FLAG. Please keep this macro in sync with +# AX_APPEND_LINK_FLAGS. +# +# LICENSE +# +# Copyright (c) 2011 Maarten Bosmans +# +# This program is free software: you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation, either version 3 of the License, or (at your +# option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General +# Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program. If not, see . +# +# As a special exception, the respective Autoconf Macro's copyright owner +# gives unlimited permission to copy, distribute and modify the configure +# scripts that are the output of Autoconf when processing the Macro. You +# need not follow the terms of the GNU General Public License when using +# or distributing such scripts, even though portions of the text of the +# Macro appear in them. The GNU General Public License (GPL) does govern +# all other use of the material that constitutes the Autoconf Macro. +# +# This special exception to the GPL applies to versions of the Autoconf +# Macro released by the Autoconf Archive. When you make and distribute a +# modified version of the Autoconf Macro, you may extend this special +# exception to the GPL to apply to your modified version as well. + +#serial 5 + +AC_DEFUN([AX_APPEND_COMPILE_FLAGS], +[AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG]) +AX_REQUIRE_DEFINED([AX_APPEND_FLAG]) +for flag in $1; do + AX_CHECK_COMPILE_FLAG([$flag], [AX_APPEND_FLAG([$flag], [$2])], [], [$3], [$4]) +done +])dnl AX_APPEND_COMPILE_FLAGS -- cgit v1.2.1