From 717e821b99797845e1bef47d862f8cb0fb69cfc9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niklas=20Hamb=C3=BCchen?= Date: Tue, 2 Jul 2019 22:30:15 +0200 Subject: [PATCH] autoconf: Allow overriding CFLAGS/CXXFLAGS from outside. As is normal for autoconf-based projects. For example, it is a common use case to do ./configure CXXFLAGS=-O0 This did not work for nix until now, because the `CXXFLAGS=` declaration would unconditionally erase what the user had specified. The custom `OPTIMIZE` flag is removed, but the default `-O3` is retained; autoconf would default to `-g -O2` by default otherwise as documented on: https://www.gnu.org/software/autoconf/manual/autoconf-2.60/html_node/C-Compiler.html https://www.gnu.org/software/autoconf/manual/autoconf-2.60/html_node/C_002b_002b-Compiler.html --- Makefile | 7 ------- configure.ac | 6 ++++-- perl/Makefile | 7 ------- perl/configure.ac | 6 ++++-- 4 files changed, 8 insertions(+), 18 deletions(-) diff --git a/Makefile b/Makefile index 45a3338ed..9ac82fda6 100644 --- a/Makefile +++ b/Makefile @@ -19,11 +19,4 @@ GLOBAL_CXXFLAGS += -g -Wall -include config.h -include Makefile.config -OPTIMIZE = 1 - -ifeq ($(OPTIMIZE), 1) - GLOBAL_CFLAGS += -O3 - GLOBAL_CXXFLAGS += -O3 -endif - include mk/lib.mk diff --git a/configure.ac b/configure.ac index 3a486fab8..571bb54d8 100644 --- a/configure.ac +++ b/configure.ac @@ -50,8 +50,10 @@ AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier ('cpu-os')]) test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var -CFLAGS= -CXXFLAGS= +# Set default flags for nix (as per AC_PROG_CC/CXX docs), +# while still allowing the user to override them from the command line. +: ${CFLAGS="-O3"} +: ${CXXFLAGS="-O3"} AC_PROG_CC AC_PROG_CXX AC_PROG_CPP diff --git a/perl/Makefile b/perl/Makefile index 284c75022..f36f5d0e9 100644 --- a/perl/Makefile +++ b/perl/Makefile @@ -4,11 +4,4 @@ GLOBAL_CXXFLAGS += -g -Wall -include Makefile.config -OPTIMIZE = 1 - -ifeq ($(OPTIMIZE), 1) - GLOBAL_CFLAGS += -O3 - GLOBAL_CXXFLAGS += -O3 -endif - include mk/lib.mk diff --git a/perl/configure.ac b/perl/configure.ac index 966700695..e8e3610a8 100644 --- a/perl/configure.ac +++ b/perl/configure.ac @@ -2,8 +2,10 @@ AC_INIT(nix-perl, m4_esyscmd([bash -c "echo -n $(cat ../.version)$VERSION_SUFFIX AC_CONFIG_SRCDIR(MANIFEST) AC_CONFIG_AUX_DIR(../config) -CFLAGS= -CXXFLAGS= +# Set default flags for nix (as per AC_PROG_CC/CXX docs), +# while still allowing the user to override them from the command line. +: ${CFLAGS="-O3"} +: ${CXXFLAGS="-O3"} AC_PROG_CC AC_PROG_CXX AX_CXX_COMPILE_STDCXX_11