From 5bb3063eecc44ae19e4f679c866c42014e8f495d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Verschelde?= Date: Thu, 21 Jul 2022 11:35:38 +0200 Subject: [PATCH] SCons: Refactor Linux linker options with `linker=` The new option is `linker` and lets the user specify the argument to the`-fuse_ld=` linker flag directly. The supported options are: - `default`: No change, typically uses GNU ld (bfd) unless the user or distro picked a different default `/usr/bin/ld`. - `bfd`: GNU ld from binutils - `gold`: GNU gold from binutils - `lld`: lld from LLVM - `mold`: mold, an extremely fast modern linker, not (yet) intended for use in production but great for development speed. Provided by distro `mold` package or needs to be compiled from source and installed to `/usr` otherwise. Deprecates the `use_lld=yes` option, and make lld actually usable with GCC too. Not all the above are compatible or recommend for LTO, we recommend using GNU ld with GCC LTO, or lld with LLVM ThinLTO. (cherry picked from commit 534f85add1daec0669a1f18edd2cc456f9a296ef) --- .github/workflows/linux_builds.yml | 4 +-- platform/x11/detect.py | 53 +++++++++++++++++++++--------- 2 files changed, 40 insertions(+), 17 deletions(-) diff --git a/.github/workflows/linux_builds.yml b/.github/workflows/linux_builds.yml index bf196a1e7982..21d59b615ccd 100644 --- a/.github/workflows/linux_builds.yml +++ b/.github/workflows/linux_builds.yml @@ -27,11 +27,11 @@ jobs: build-mono: true artifact: true - - name: Editor and sanitizers (target=debug, tools=yes, use_asan=yes, use_ubsan=yes) + - name: Editor and sanitizers (target=debug, tools=yes, use_asan=yes, use_ubsan=yes, linker=gold) cache-name: linux-editor-sanitizers target: debug tools: true - sconsflags: use_asan=yes use_ubsan=yes + sconsflags: use_asan=yes use_ubsan=yes linker=gold test: true bin: "./bin/godot.x11.tools.64s" build-mono: false diff --git a/platform/x11/detect.py b/platform/x11/detect.py index 13857809951e..1a0077bf29b0 100644 --- a/platform/x11/detect.py +++ b/platform/x11/detect.py @@ -64,9 +64,10 @@ def get_opts(): from SCons.Variables import BoolVariable, EnumVariable return [ + EnumVariable("linker", "Linker program", "default", ("default", "bfd", "gold", "lld", "mold")), BoolVariable("use_llvm", "Use the LLVM compiler", False), - BoolVariable("use_lld", "Use the LLD linker", False), - BoolVariable("use_thinlto", "Use ThinLTO", False), + BoolVariable("use_lld", "Use the LLD linker (deprecated, use `linker=lld` instead).", False), + BoolVariable("use_thinlto", "Use ThinLTO (LLVM only, requires linker=lld, implies use_lto=yes)", False), BoolVariable("use_static_cpp", "Link libgcc and libstdc++ statically for better portability", True), BoolVariable("use_ubsan", "Use LLVM/GCC compiler undefined behavior sanitizer (UBSAN)", False), BoolVariable("use_asan", "Use LLVM/GCC compiler address sanitizer (ASAN))", False), @@ -146,14 +147,37 @@ def configure(env): env.extra_suffix = ".llvm" + env.extra_suffix if env["use_lld"]: - if env["use_llvm"]: - env.Append(LINKFLAGS=["-fuse-ld=lld"]) - if env["use_thinlto"]: - # A convenience so you don't need to write use_lto too when using SCons - env["use_lto"] = True + if env["linker"] != "default": + print("Can't specify both `use_lld=yes` and a non-default `linker`. Remove `use_lld=yes`.") + sys.exit(255) + print("The `use_lld=yes` option is deprecated, use `linker=lld` instead.") + env["linker"] == "lld" + + if env["linker"] != "default": + print("Using linker program: " + env["linker"]) + if env["linker"] == "mold" and using_gcc(env): # GCC < 12.1 doesn't support -fuse-ld=mold. + cc_semver = tuple(get_compiler_version(env)) + if cc_semver < (12, 1): + found_wrapper = False + for path in ["/usr/libexec", "/usr/local/libexec", "/usr/lib", "/usr/local/lib"]: + if os.path.isfile(path + "/mold/ld"): + env.Append(LINKFLAGS=["-B" + path + "/mold"]) + found_wrapper = True + break + if not found_wrapper: + print("Couldn't locate mold installation path. Make sure it's installed in /usr or /usr/local.") + sys.exit(255) + else: + env.Append(LINKFLAGS=["-fuse-ld=mold"]) else: - print("Using LLD with GCC is not supported yet. Try compiling with 'use_llvm=yes'.") + env.Append(LINKFLAGS=["-fuse-ld=%s" % env["linker"]]) + + if env["use_thinlto"]: + if not env["use_llvm"] or env["linker"] != "lld": + print("ThinLTO is only compatible with LLVM and the LLD linker, use `use_llvm=yes linker=lld`.") sys.exit(255) + else: + env["use_lto"] = True # ThinLTO implies LTO if env["use_ubsan"] or env["use_asan"] or env["use_lsan"] or env["use_tsan"] or env["use_msan"]: env.extra_suffix += "s" @@ -192,16 +216,15 @@ def configure(env): env.Append(LINKFLAGS=["-fsanitize=memory"]) if env["use_lto"]: - if not env["use_llvm"] and env.GetOption("num_jobs") > 1: + if env["use_thinlto"]: + env.Append(CCFLAGS=["-flto=thin"]) + env.Append(LINKFLAGS=["-flto=thin"]) + elif not env["use_llvm"] and env.GetOption("num_jobs") > 1: env.Append(CCFLAGS=["-flto"]) env.Append(LINKFLAGS=["-flto=" + str(env.GetOption("num_jobs"))]) else: - if env["use_lld"] and env["use_thinlto"]: - env.Append(CCFLAGS=["-flto=thin"]) - env.Append(LINKFLAGS=["-flto=thin"]) - else: - env.Append(CCFLAGS=["-flto"]) - env.Append(LINKFLAGS=["-flto"]) + env.Append(CCFLAGS=["-flto"]) + env.Append(LINKFLAGS=["-flto"]) if not env["use_llvm"]: env["RANLIB"] = "gcc-ranlib"