build, win: make LTCG optional

Disables Link Time Code Generation by default. Adds ‘ltcg’ vcbuild
option to enable it. LTCG will be used by default by release and CI
builds.
PR-URL: #21186
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

Author: bzoz

common.gypi

@@ -16,6 +16,7 @@
 'node_use_v8_platform%': 'true',
 'node_use_bundled_v8%': 'true',
 'node_module_version%': '',
+'node_with_ltcg%': '',
 
 'node_tag%': '',
 'uv_library%': 'static_library',
@@ -192,36 +193,51 @@
 'RuntimeLibrary': 0# MultiThreaded (/MT)
  }
  }
+ }],
+ ['node_with_ltcg=="true"', {
+'msvs_settings': {
+'VCCLCompilerTool': {
+'WholeProgramOptimization': 'true'# /GL, whole program optimization, needed for LTCG
+ },
+'VCLibrarianTool': {
+'AdditionalOptions': [
+'/LTCG:INCREMENTAL', # link time code generation
+ ]
+ },
+'VCLinkerTool': {
+'OptimizeReferences': 2, # /OPT:REF
+'EnableCOMDATFolding': 2, # /OPT:ICF
+'LinkIncremental': 1, # disable incremental linking
+'AdditionalOptions': [
+'/LTCG:INCREMENTAL', # incremental link-time code generation
+ ]
+ }
+ }
+ }, {
+'msvs_settings': {
+'VCCLCompilerTool': {
+'WholeProgramOptimization': 'false'
+ },
+'VCLinkerTool': {
+'LinkIncremental': 2# enable incremental linking
+ }
+ }
  }]
  ],
 'msvs_settings': {
 'VCCLCompilerTool': {
 'Optimization': 3, # /Ox, full optimization
 'FavorSizeOrSpeed': 1, # /Ot, favor speed over size
 'InlineFunctionExpansion': 2, # /Ob2, inline anything eligible
-'WholeProgramOptimization': 'true', # /GL, whole program optimization, needed for LTCG
 'OmitFramePointers': 'true',
 'EnableFunctionLevelLinking': 'true',
 'EnableIntrinsicFunctions': 'true',
 'RuntimeTypeInfo': 'false',
 'AdditionalOptions': [
 '/MP', # compile across multiple CPUs
  ],
- },
-'VCLibrarianTool': {
-'AdditionalOptions': [
-'/LTCG', # link time code generation
- ],
- },
-'VCLinkerTool': {
-'OptimizeReferences': 2, # /OPT:REF
-'EnableCOMDATFolding': 2, # /OPT:ICF
-'LinkIncremental': 1, # disable incremental linking
-'AdditionalOptions': [
-'/LTCG:INCREMENTAL', # incremental link-time code generation
- ],
- },
- },
+ }
+ }
  }
  },
 # Forcibly disable -Werror. We support a wide range of compilers, it's

configure

@@ -425,6 +425,11 @@ intl_optgroup.add_option('--with-icu-source',
  dest='with_icu_source',
  help='Intl mode: optional local path to icu/ dir, or path/URL of icu source archive.')
 
+parser.add_option('--with-ltcg',
+ action='store_true',
+ dest='with_ltcg',
+ help='Use Link Time Code Generation. This feature is only available on Windows.')
+
 intl_optgroup.add_option('--download',
  action='store',
  dest='download_list',
@@ -953,6 +958,10 @@ def configure_node(o):
  else:
  o['variables']['node_use_perfctr'] = 'false'
 
+ o['variables']['node_with_ltcg'] = b(options.with_ltcg)
+if flavor != 'win' and options.with_ltcg:
+ raise Exception('Link Time Code Generation is only supported on Windows.')
+
 if options.tag:
  o['variables']['node_tag'] = '-' + options.tag
  else:

vcbuild.bat

@@ -15,6 +15,7 @@ cd %~dp0
 setconfig=Release
 settarget=Build
 settarget_arch=x64
+setltcg=
 settarget_env=
 setnoprojgen=
 setprojgen=
@@ -61,7 +62,7 @@ set doc=
 :next-arg
 if"%1"==""goto args-done
 if /i "%1"=="debug"setconfig=Debug&goto arg-ok
-if /i "%1"=="release"setconfig=Release&goto arg-ok
+if /i "%1"=="release"setconfig=Release&set ltcg=1&goto arg-ok
 if /i "%1"=="clean"settarget=Clean&goto arg-ok
 if /i "%1"=="ia32"settarget_arch=x86&goto arg-ok
 if /i "%1"=="x86"settarget_arch=x86&goto arg-ok
@@ -75,6 +76,7 @@ if /i "%1"=="sign" set sign=1&goto arg-ok
 if /i "%1"=="nosnapshot"setnosnapshot=1&goto arg-ok
 if /i "%1"=="noetw"setnoetw=1&goto arg-ok
 if /i "%1"=="noperfctr"setnoperfctr=1&goto arg-ok
+if /i "%1"=="ltcg"setltcg=1&goto arg-ok
 if /i "%1"=="licensertf"setlicensertf=1&goto arg-ok
 if /i "%1"=="test"settest_args=%test_args% -J %common_test_suites%&set lint_cpp=1&set lint_js=1&set lint_md=1&goto arg-ok
 if /i "%1"=="test-ci"settest_args=%test_args%%test_ci_args% -p tap --logfile test.tap %common_test_suites%&set cctest_args=%cctest_args% --gtest_output=tap:cctest.tap&goto arg-ok
@@ -150,6 +152,7 @@ if defined build_release (
 setdownload_arg="--download=all"
 seti18n_arg=small-icu
 setprojgen=1
+setltcg=1
 )
 
 :: assign path to node_exe
@@ -162,6 +165,7 @@ if "%config%"=="Debug" set configure_flags=%configure_flags% --debug
 ifdefined nosnapshot setconfigure_flags=%configure_flags% --without-snapshot
 ifdefined noetw setconfigure_flags=%configure_flags% --without-etw&setnoetw_msi_arg=/p:NoETW=1
 ifdefined noperfctr setconfigure_flags=%configure_flags% --without-perfctr&setnoperfctr_msi_arg=/p:NoPerfCtr=1
+ifdefined ltcg setconfigure_flags=%configure_flags% --with-ltcg
 ifdefined release_urlbase setconfigure_flags=%configure_flags% --release-urlbase=%release_urlbase%
 ifdefined download_arg setconfigure_flags=%configure_flags%%download_arg%
 ifdefined enable_vtune_arg setconfigure_flags=%configure_flags% --enable-vtune-profiling
@@ -656,7 +660,7 @@ del .used_configure_flags
 gotoexit
 
 :help
-echo vcbuild.bat [debug/release] [msi] [doc] [test/test-ci/test-all/test-addons/test-addons-napi/test-internet/test-pummel/test-simple/test-message/test-gc/test-tick-processor/test-known-issues/test-node-inspect/test-check-deopts/test-npm/test-async-hooks/test-v8/test-v8-intl/test-v8-benchmarks/test-v8-all] [ignore-flaky] [static/dll] [noprojgen] [projgen] [small-icu/full-icu/without-intl] [nobuild] [nosnapshot] [noetw] [noperfctr] [licensetf] [sign] [ia32/x86/x64] [vs2017] [download-all] [enable-vtune] [lint/lint-ci/lint-js/lint-js-ci/lint-md] [lint-md-build] [package] [build-release] [upload] [no-NODE-OPTIONS] [link-module path-to-module] [debug-http2] [debug-nghttp2] [clean] [no-cctest] [openssl-no-asm]
+echo vcbuild.bat [debug/release] [msi] [doc] [test/test-ci/test-all/test-addons/test-addons-napi/test-internet/test-pummel/test-simple/test-message/test-gc/test-tick-processor/test-known-issues/test-node-inspect/test-check-deopts/test-npm/test-async-hooks/test-v8/test-v8-intl/test-v8-benchmarks/test-v8-all] [ignore-flaky] [static/dll] [noprojgen] [projgen] [small-icu/full-icu/without-intl] [nobuild] [nosnapshot] [noetw] [noperfctr] [ltcg] [licensetf] [sign] [ia32/x86/x64] [vs2017] [download-all] [enable-vtune] [lint/lint-ci/lint-js/lint-js-ci/lint-md] [lint-md-build] [package] [build-release] [upload] [no-NODE-OPTIONS] [link-module path-to-module] [debug-http2] [debug-nghttp2] [clean] [no-cctest] [openssl-no-asm]
 echo Examples:
 echo vcbuild.bat : builds release build
 echo vcbuild.bat debug : builds debug build