From 4aee447af1ab29d094e917b94ec3e3d4af36f1cd Mon Sep 17 00:00:00 2001 From: Jean-Marc Lasgouttes Date: Tue, 13 Oct 2020 18:26:34 +0200 Subject: [PATCH] Use -Wno-deprecated-copy only when supported by compiler This is better than depending on compiler version. In particular, Apple clang versions do not match regular clang versions. Note that -Wno-deprecated-copy will always be used with g++, since this compiler allows to suppress warnings it does not know about (-Wno-zorg is valid, even though -Wzorg triggers an error). --- config/lyxinclude.m4 | 11 ++++---- m4/ax_check_compile_flag.m4 | 53 +++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+), 5 deletions(-) create mode 100644 m4/ax_check_compile_flag.m4 diff --git a/config/lyxinclude.m4 b/config/lyxinclude.m4 index a943ddd7b6..b61ea59ac5 100644 --- a/config/lyxinclude.m4 +++ b/config/lyxinclude.m4 @@ -409,11 +409,12 @@ if test x$GXX = xyes; then dnl Warnings are for preprocessor too if test x$enable_warnings = xyes ; then AM_CPPFLAGS="$AM_CPPFLAGS -Wall -Wextra" - case $gxx_version in - 9.*|10.*|clang-10*|clang-11*) - AM_CXXFLAGS="$AM_CXXFLAGS -Wno-deprecated-copy";; - *);; - esac + dnl Shut off warning -Wdeprecated-copy, which triggers too much + dnl note that g++ always accepts -Wno-xxx, even when -Wxxx is an error. + AC_LANG_PUSH(C++) + AX_CHECK_COMPILE_FLAG([-Wno-deprecated-copy], + [AM_CXXFLAGS="$AM_CXXFLAGS -Wno-deprecated-copy"], [], [-Werror]) + AC_LANG_POP(C++) fi case $gxx_version in 2.*|3.*|4.@<:@0-6@:>@) AC_MSG_ERROR([gcc >= 4.7 is required]);; diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4 new file mode 100644 index 0000000000..bd753b34d7 --- /dev/null +++ b/m4/ax_check_compile_flag.m4 @@ -0,0 +1,53 @@ +# =========================================================================== +# https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT]) +# +# DESCRIPTION +# +# Check whether the given FLAG works with the current language's compiler +# or gives an error. (Warnings, however, are ignored) +# +# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on +# success/failure. +# +# 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: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this +# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG. +# +# LICENSE +# +# Copyright (c) 2008 Guido U. Draheim +# Copyright (c) 2011 Maarten Bosmans +# +# Copying and distribution of this file, with or without modification, are +# permitted in any medium without royalty provided the copyright notice +# and this notice are preserved. This file is offered as-is, without any +# warranty. + +#serial 6 + +AC_DEFUN([AX_CHECK_COMPILE_FLAG], +[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF +AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl +AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [ + ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS + _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1" + AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], + [AS_VAR_SET(CACHEVAR,[yes])], + [AS_VAR_SET(CACHEVAR,[no])]) + _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags]) +AS_VAR_IF(CACHEVAR,yes, + [m4_default([$2], :)], + [m4_default([$3], :)]) +AS_VAR_POPDEF([CACHEVAR])dnl +])dnl AX_CHECK_COMPILE_FLAGS