From 35a15e619161798820b2bd6ff46178c5b7ccebcf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Verschelde?= Date: Tue, 13 Sep 2022 17:01:47 +0200 Subject: [PATCH] SCons: Refactor handling of `production` flag and per-platform LTO defaults Fixup to #63288. See #65583 for the bug report. Co-authored-by: Cyberrebell --- SConstruct | 71 ++++++++++++++++++------------------- platform/android/detect.py | 7 ++-- platform/ios/detect.py | 9 ++--- platform/linuxbsd/detect.py | 4 +++ platform/macos/detect.py | 9 +++-- platform/web/detect.py | 4 +++ platform/windows/detect.py | 8 +++++ 7 files changed, 65 insertions(+), 47 deletions(-) diff --git a/SConstruct b/SConstruct index 891f1116e1f..200e8e59842 100644 --- a/SConstruct +++ b/SConstruct @@ -170,7 +170,7 @@ opts.Add(EnumVariable("arch", "CPU architecture", "auto", ["auto"] + architectur opts.Add(EnumVariable("float", "Floating-point precision", "32", ("32", "64"))) opts.Add(EnumVariable("optimize", "Optimization type", "speed", ("speed", "size", "none"))) opts.Add(BoolVariable("production", "Set defaults to build Godot for use in production", False)) -opts.Add(EnumVariable("lto", "Link-time optimization (for production buids)", "none", ("none", "thin", "full"))) +opts.Add(EnumVariable("lto", "Link-time optimization (for production buids)", "none", ("none", "auto", "thin", "full"))) # Components opts.Add(BoolVariable("deprecated", "Enable compatibility code for deprecated and removed features", True)) @@ -460,19 +460,42 @@ if selected_platform in platform_list: env["LINKFLAGS"] = "" env.Append(LINKFLAGS=str(LINKFLAGS).split()) - # Platform specific flags + # Platform specific flags. + # These can sometimes override default options. flag_list = platform_flags[selected_platform] for f in flag_list: if not (f[0] in ARGUMENTS) or ARGUMENTS[f[0]] == "auto": # Allow command line to override platform flags env[f[0]] = f[1] - # Must happen after the flags' definition, so that they can be used by platform detect + # 'dev' and 'production' are aliases to set default options if they haven't been + # set manually by the user. + # These need to be checked *after* platform specific flags so that different + # default values can be set (e.g. to keep LTO off for `production` on some platforms). + if env["dev"]: + env["verbose"] = methods.get_cmdline_bool("verbose", True) + env["warnings"] = ARGUMENTS.get("warnings", "extra") + env["werror"] = methods.get_cmdline_bool("werror", True) + if env["tools"]: + env["tests"] = methods.get_cmdline_bool("tests", True) + if env["production"]: + env["use_static_cpp"] = methods.get_cmdline_bool("use_static_cpp", True) + env["debug_symbols"] = methods.get_cmdline_bool("debug_symbols", False) + # LTO "auto" means we handle the preferred option in each platform detect.py. + env["lto"] = ARGUMENTS.get("lto", "auto") + if not env["tools"] and env["target"] == "debug": + print( + "WARNING: Requested `production` build with `tools=no target=debug`, " + "this will give you a full debug template (use `target=release_debug` " + "for an optimized template with debug features)." + ) + + # Must happen after the flags' definition, as configure is when most flags + # are actually handled to change compile options, etc. detect.configure(env) - print( - 'Building for platform "%s", architecture "%s", %s, target "%s".' - % (selected_platform, env["arch"], "editor" if env["tools"] else "template", env["target"]) - ) + # Needs to happen after configure to handle "auto". + if env["lto"] != "none": + print("Using LTO: " + env["lto"]) # Set our C and C++ standard requirements. # C++17 is required as we need guaranteed copy elision as per GH-36436. @@ -488,36 +511,10 @@ if selected_platform in platform_list: # We apply it to CCFLAGS (both C and C++ code) in case it impacts C features. env.Prepend(CCFLAGS=["/std:c++17"]) - # 'dev' and 'production' are aliases to set default options if they haven't been set - # manually by the user. - if env["dev"]: - env["verbose"] = methods.get_cmdline_bool("verbose", True) - env["warnings"] = ARGUMENTS.get("warnings", "extra") - env["werror"] = methods.get_cmdline_bool("werror", True) - if env["tools"]: - env["tests"] = methods.get_cmdline_bool("tests", True) - if env["production"]: - env["use_static_cpp"] = methods.get_cmdline_bool("use_static_cpp", True) - env["lto"] = ARGUMENTS.get("lto", "full") - env["debug_symbols"] = methods.get_cmdline_bool("debug_symbols", False) - if not env["tools"] and env["target"] == "debug": - print( - "WARNING: Requested `production` build with `tools=no target=debug`, " - "this will give you a full debug template (use `target=release_debug` " - "for an optimized template with debug features)." - ) - if env.msvc: - print( - "WARNING: For `production` Windows builds, you should use MinGW with GCC " - "or Clang instead of Visual Studio, as they can better optimize the " - "GDScript VM in a very significant way. MSVC LTO also doesn't work " - "reliably for our use case." - "If you want to use MSVC nevertheless for production builds, set " - "`debug_symbols=no lto=none` instead of the `production=yes` option." - ) - Exit(255) - if env["lto"] != "none": - print("Using LTO: " + env["lto"]) + print( + 'Building for platform "%s", architecture "%s", %s, target "%s".' + % (selected_platform, env["arch"], "editor" if env["tools"] else "template", env["target"]) + ) # Enforce our minimal compiler version requirements cc_version = methods.get_compiler_version(env) or { diff --git a/platform/android/detect.py b/platform/android/detect.py index 1d9bcdd932f..a31bba745f2 100644 --- a/platform/android/detect.py +++ b/platform/android/detect.py @@ -47,9 +47,6 @@ def get_flags(): return [ ("arch", "arm64"), # Default for convenience. ("tools", False), - # Benefits of LTO for Android (size, performance) haven't been clearly established yet. - # So for now we override the default value which may be set when using `production=yes`. - ("lto", "none"), ] @@ -136,6 +133,10 @@ def configure(env): env.Append(CPPFLAGS=["-UNDEBUG"]) # LTO + + if env["lto"] == "auto": # LTO benefits for Android (size, performance) haven't been clearly established yet. + env["lto"] = "none" + if env["lto"] != "none": if env["lto"] == "thin": env.Append(CCFLAGS=["-flto=thin"]) diff --git a/platform/ios/detect.py b/platform/ios/detect.py index ed7e714c4e3..d5e6ee4b468 100644 --- a/platform/ios/detect.py +++ b/platform/ios/detect.py @@ -39,9 +39,6 @@ def get_flags(): ("arch", "arm64"), # Default for convenience. ("tools", False), ("use_volk", False), - # Disable by default even if production is set, as it makes linking in Xcode - # on exports very slow and that's not what most users expect. - ("lto", "none"), ] @@ -73,7 +70,11 @@ def configure(env): env.Append(CCFLAGS=["-gdwarf-2", "-O0"]) env.Append(CPPDEFINES=["_DEBUG", ("DEBUG", 1)]) - # LTO + ## LTO + + if env["lto"] == "auto": # Disable by default as it makes linking in Xcode very slow. + env["lto"] = "none" + if env["lto"] != "none": if env["lto"] == "thin": env.Append(CCFLAGS=["-flto=thin"]) diff --git a/platform/linuxbsd/detect.py b/platform/linuxbsd/detect.py index 36644d5f295..12d2432eeab 100644 --- a/platform/linuxbsd/detect.py +++ b/platform/linuxbsd/detect.py @@ -171,6 +171,10 @@ def configure(env): env.Append(LINKFLAGS=["-fsanitize=memory"]) # LTO + + if env["lto"] == "auto": # Full LTO for production. + env["lto"] = "full" + if env["lto"] != "none": if env["lto"] == "thin": if not env["use_llvm"]: diff --git a/platform/macos/detect.py b/platform/macos/detect.py index bcf47766097..834ac935d84 100644 --- a/platform/macos/detect.py +++ b/platform/macos/detect.py @@ -40,9 +40,6 @@ def get_flags(): return [ ("arch", detect_arch()), ("use_volk", False), - # Benefits of LTO for macOS (size, performance) haven't been clearly established yet. - # So for now we override the default value which may be set when using `production=yes`. - ("lto", "none"), ] @@ -170,6 +167,10 @@ def configure(env): env["AS"] = basecmd + "as" # LTO + + if env["lto"] == "auto": # LTO benefits for macOS (size, performance) haven't been clearly established yet. + env["lto"] = "none" + if env["lto"] != "none": if env["lto"] == "thin": env.Append(CCFLAGS=["-flto=thin"]) @@ -178,6 +179,8 @@ def configure(env): env.Append(CCFLAGS=["-flto"]) env.Append(LINKFLAGS=["-flto"]) + # Sanitizers + if env["use_ubsan"] or env["use_asan"] or env["use_tsan"]: env.extra_suffix += ".san" env.Append(CCFLAGS=["-DSANITIZERS_ENABLED"]) diff --git a/platform/web/detect.py b/platform/web/detect.py index 08f964db92e..9cce73efc47 100644 --- a/platform/web/detect.py +++ b/platform/web/detect.py @@ -109,6 +109,10 @@ def configure(env): env["ENV"] = os.environ # LTO + + if env["lto"] == "auto": # Full LTO for production. + env["lto"] = "full" + if env["lto"] != "none": if env["lto"] == "thin": env.Append(CCFLAGS=["-flto=thin"]) diff --git a/platform/windows/detect.py b/platform/windows/detect.py index e6e1874fc07..52a959b34a4 100644 --- a/platform/windows/detect.py +++ b/platform/windows/detect.py @@ -448,6 +448,9 @@ def configure_msvc(env, vcvars_msvc_config): ## LTO + if env["lto"] == "auto": # No LTO by default for MSVC, doesn't help. + env["lto"] = "none" + if env["lto"] != "none": if env["lto"] == "thin": print("ThinLTO is only compatible with LLVM, use `use_llvm=yes` or `lto=full`.") @@ -564,6 +567,11 @@ def configure_mingw(env): if try_cmd("gcc-ranlib --version", env["mingw_prefix"], env["arch"]): env["RANLIB"] = mingw_bin_prefix + "gcc-ranlib" + ## LTO + + if env["lto"] == "auto": # Full LTO for production with MinGW. + env["lto"] = "full" + if env["lto"] != "none": if env["lto"] == "thin": if not env["use_llvm"]: