From cdad781d0945a39c936999b75ca18dbf066c1708 Mon Sep 17 00:00:00 2001
From: Daniele Buono <dbuono@linux.vnet.ibm.com>
Date: Fri, 4 Dec 2020 18:06:11 -0500
Subject: [PATCH] configure,meson: add option to enable LTO
This patch allows to compile QEMU with link-time optimization (LTO).
Compilation with LTO is handled directly by meson. This patch only
adds the option in configure and forwards the request to meson
Tested with all major versions of clang from 6 to 12
Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com>
Message-Id: <20201204230615.2392-2-dbuono@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
configure | 7 +++++++
meson.build | 1 +
2 files changed, 8 insertions(+)
diff --git a/configure b/configure
index 8ef0874ed5..b6fb188151 100755
--- a/configure
+++ b/configure
@@ -242,6 +242,7 @@ host_cc="cc"
audio_win_int=""
libs_qga=""
debug_info="yes"
+lto="false"
stack_protector=""
safe_stack=""
use_containers="yes"
@@ -1182,6 +1183,10 @@ for opt do
;;
--disable-werror) werror="no"
;;
+ --enable-lto) lto="true"
+ ;;
+ --disable-lto) lto="false"
+ ;;
--enable-stack-protector) stack_protector="yes"
;;
--disable-stack-protector) stack_protector="no"
@@ -1779,6 +1784,7 @@ disabled with --disable-FEATURE, default is enabled if available
module-upgrades try to load modules from alternate paths for upgrades
debug-tcg TCG debugging (default is disabled)
debug-info debugging information
+ lto Enable Link-Time Optimization.
sparse sparse checker
safe-stack SafeStack Stack Smash Protection. Depends on
clang/llvm >= 3.7 and requires coroutine backend ucontext.
@@ -6965,6 +6971,7 @@ NINJA=$ninja $meson setup \
-Db_pie=$(if test "$pie" = yes; then echo true; else echo false; fi) \
${staticpic:+-Db_staticpic=$staticpic} \
-Db_coverage=$(if test "$gcov" = yes; then echo true; else echo false; fi) \
+ -Db_lto=$lto \
-Dmalloc=$malloc -Dmalloc_trim=$malloc_trim -Dsparse=$sparse \
-Dkvm=$kvm -Dhax=$hax -Dwhpx=$whpx -Dhvf=$hvf \
-Dxen=$xen -Dxen_pci_passthrough=$xen_pci_passthrough -Dtcg=$tcg \
diff --git a/meson.build b/meson.build
index 372576f82c..d05d880114 100644
--- a/meson.build
+++ b/meson.build
@@ -2080,6 +2080,7 @@ summary_info += {'gprof enabled': config_host.has_key('CONFIG_GPROF')}
summary_info += {'sparse enabled': sparse.found()}
summary_info += {'strip binaries': get_option('strip')}
summary_info += {'profiler': config_host.has_key('CONFIG_PROFILER')}
+summary_info += {'link-time optimization (LTO)': get_option('b_lto')}
summary_info += {'static build': config_host.has_key('CONFIG_STATIC')}
if targetos == 'darwin'
summary_info += {'Cocoa support': config_host.has_key('CONFIG_COCOA')}