diff options
Diffstat (limited to 'third_party/libwebrtc/build/config/compiler/compiler.gni')
| -rw-r--r-- | third_party/libwebrtc/build/config/compiler/compiler.gni | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/third_party/libwebrtc/build/config/compiler/compiler.gni b/third_party/libwebrtc/build/config/compiler/compiler.gni new file mode 100644 index 0000000000..55ae571ab7 --- /dev/null +++ b/third_party/libwebrtc/build/config/compiler/compiler.gni @@ -0,0 +1,324 @@ +# Copyright 2015 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +import("//build/config/chrome_build.gni") +import("//build/config/chromecast_build.gni") +import("//build/config/chromeos/args.gni") +import("//build/config/chromeos/ui_mode.gni") +import("//build/config/compiler/pgo/pgo.gni") +import("//build/config/sanitizers/sanitizers.gni") +import("//build/toolchain/cc_wrapper.gni") +import("//build/toolchain/goma.gni") +import("//build/toolchain/toolchain.gni") +import("//build_overrides/build.gni") + +if (is_android) { + import("//build/config/android/abi.gni") +} +if (target_cpu == "arm" || target_cpu == "arm64") { + import("//build/config/arm.gni") +} + +if (is_apple) { + import("//build/config/apple/symbols.gni") +} + +if (is_ios) { + import("//build/config/ios/config.gni") +} + +declare_args() { + # Default to warnings as errors for default workflow, where we catch + # warnings with known toolchains. Allow overriding this e.g. for Chromium + # builds on Linux that could use a different version of the compiler. + # With GCC, warnings in no-Chromium code are always not treated as errors. + treat_warnings_as_errors = true + + # How many symbols to include in the build. This affects the performance of + # the build since the symbols are large and dealing with them is slow. + # 2 means regular build with symbols. + # 1 means minimal symbols, usually enough for backtraces only. Symbols with + # internal linkage (static functions or those in anonymous namespaces) may not + # appear when using this level. + # 0 means no symbols. + # -1 means auto-set according to debug/release and platform. + symbol_level = -1 + + # Android-only: Strip the debug info of libraries within lib.unstripped to + # reduce size. As long as symbol_level > 0, this will still allow stacks to be + # symbolized. + strip_debug_info = false + + # Compile in such a way as to enable profiling of the generated code. For + # example, don't omit the frame pointer and leave in symbols. + enable_profiling = false + + # use_debug_fission: whether to use split DWARF debug info + # files. This can reduce link time significantly, but is incompatible + # with some utilities such as icecc and ccache. Requires gold and + # gcc >= 4.8 or clang. + # http://gcc.gnu.org/wiki/DebugFission + # + # This is a placeholder value indicating that the code below should set + # the default. This is necessary to delay the evaluation of the default + # value expression until after its input values such as use_gold have + # been set, e.g. by a toolchain_args() block. + use_debug_fission = "default" + + # Enables support for ThinLTO, which links 3x-10x faster than full LTO. See + # also http://blog.llvm.org/2016/06/thinlto-scalable-and-incremental-lto.html + # Use it by default on official-optimized android and Chrome OS builds, but + # not ARC or linux-chromeos since it's been seen to not play nicely with + # Chrome's clang. crbug.com/1033839 + use_thin_lto = + is_cfi || + (is_official_build && chrome_pgo_phase != 1 && + (is_linux || is_win || (is_android && target_os != "chromeos") || + ((is_chromeos_ash || is_chromeos_lacros) && is_chromeos_device))) + + # If true, use Goma for ThinLTO code generation where applicable. + use_goma_thin_lto = false + + # Whether we're using a sample profile collected on an architecture different + # than the one we're compiling for. + # + # It's currently not possible to collect AFDO profiles on anything but + # x86{,_64}. + using_mismatched_sample_profile = target_cpu != "x64" && target_cpu != "x86" + + # Whether an error should be raised on attempts to make debug builds with + # is_component_build=false. Very large debug symbols can have unwanted side + # effects so this is enforced by default for chromium. + forbid_non_component_debug_builds = build_with_chromium + + # Exclude unwind tables by default for official builds as unwinding can be + # done from stack dumps produced by Crashpad at a later time "offline" in the + # crash server. Since this increases binary size, we don't recommend including + # them in shipping builds. + # For unofficial (e.g. development) builds and non-Chrome branded (e.g. Cronet + # which doesn't use Crashpad, crbug.com/479283) builds it's useful to be able + # to unwind at runtime. + # Include the unwind tables on Android even for official builds, as otherwise + # the crash dumps generated by Android's debuggerd are largely useless, and + # having this additional mechanism to understand issues is particularly helpful + # to WebView. + exclude_unwind_tables = is_official_build && !is_android + + # Where to redirect clang crash diagnoses + clang_diagnostic_dir = + rebase_path("//tools/clang/crashreports", root_build_dir) + + # Mark binaries as compatible with Shadow Stack of Control-flow Enforcement + # Technology (CET). If Windows version and hardware supports the feature and + # it's enabled by OS then additional validation of return address will be + # performed as mitigation against Return-oriented programming (ROP). + # https://chromium.googlesource.com/chromium/src/+/main/docs/design/sandbox.md#cet-shadow-stack + enable_cet_shadow_stack = target_cpu == "x64" +} + +assert(!is_cfi || use_thin_lto, "CFI requires ThinLTO") + +# If true, optimize for size. Does not affect windows builds. +# Linux & Mac favor speed over size. +# TODO(brettw) it's weird that Mac and desktop Linux are different. We should +# explore favoring size over speed in this case as well. +optimize_for_size = is_android || is_chromecast || is_fuchsia || is_ios + +declare_args() { + # Whether we should consider the profile we're using to be accurate. Accurate + # profiles have the benefit of (potentially substantial) binary size + # reductions, by instructing the compiler to optimize cold and uncovered + # functions heavily for size. This often comes at the cost of performance. + sample_profile_is_accurate = optimize_for_size +} + +# Determine whether to enable or disable frame pointers, based on the platform +# and build arguments. +# TODO(crbug.com/1052397): Consider changing is_chromeos_ash to is_chromeos after +# lacros-chrome switches to target_os="chromeos". +if (is_chromeos_ash || is_chromeos_lacros) { + # ChromeOS generally prefers frame pointers, to support CWP. + # However, Clang does not currently generate usable frame pointers in ARM + # 32-bit builds (https://bugs.llvm.org/show_bug.cgi?id=18505) so disable them + # there to avoid the unnecessary overhead. + enable_frame_pointers = target_cpu != "arm" +} else if (is_apple || is_linux || is_chromeos) { + enable_frame_pointers = true +} else if (is_win) { + # 64-bit Windows ABI doesn't support frame pointers. + if (target_cpu == "x64") { + enable_frame_pointers = false + } else { + enable_frame_pointers = true + } +} else if (is_android) { + enable_frame_pointers = + enable_profiling || + # Ensure that stacks from arm64 crash dumps are usable (crbug.com/391706). + target_cpu == "arm64" || + # For x86 Android, unwind tables are huge without frame pointers + # (crbug.com/762629). Enabling frame pointers grows the code size slightly + # but overall shrinks binaries considerably by avoiding huge unwind + # tables. + (target_cpu == "x86" && !exclude_unwind_tables && optimize_for_size) || + using_sanitizer || + # For caller-callee instrumentation version which needs frame pointers to + # get the caller address. + use_call_graph +} else { + # Explicitly ask for frame pointers, otherwise: + # * Stacks may be missing for sanitizer and profiling builds. + # * Debug tcmalloc can crash (crbug.com/636489). + enable_frame_pointers = using_sanitizer || enable_profiling || is_debug +} + +# In general assume that if we have frame pointers then we can use them to +# unwind the stack. However, this requires that they are enabled by default for +# most translation units, that they are emitted correctly, and that the +# compiler or platform provides a way to access them. +can_unwind_with_frame_pointers = enable_frame_pointers +if (target_cpu == "arm" && arm_use_thumb) { + # We cannot currently unwind ARM Thumb frame pointers correctly. + # See https://bugs.llvm.org/show_bug.cgi?id=18505 + can_unwind_with_frame_pointers = false +} else if (is_win) { + # Windows 32-bit does provide frame pointers, but the compiler does not + # provide intrinsics to access them, so we don't use them. + can_unwind_with_frame_pointers = false +} + +assert(!can_unwind_with_frame_pointers || enable_frame_pointers) + +# Unwinding with CFI table is only possible on static library builds and +# requried only when frame pointers are not enabled. +can_unwind_with_cfi_table = is_android && !is_component_build && + !enable_frame_pointers && target_cpu == "arm" + +# Whether or not cfi table should be enabled on arm. +# TODO(crbug.com/1090409): Replace can_unwind_with_cfi_table with this once +# sampling profiler is enabled on android. +enable_arm_cfi_table = is_android && !is_component_build && target_cpu == "arm" + +declare_args() { + # If this running on a GPU FYI bot. + # TODO(https://crbug.com/1233871): Remove this again. + is_gpu_fyi_bot = false +} + +declare_args() { + # Set to true to use lld, the LLVM linker. + # In late bring-up on macOS (see docs/mac_lld.md). + # Tentatively used on iOS, except in cronet builds (cronet still supports 32-bit builds, which + # lld doesn't support). + # The default linker everywhere else. + use_lld = + is_clang && !(is_ios && is_cronet_build) && !(is_mac && is_gpu_fyi_bot) +} + +declare_args() { + # Whether to use the gold linker from binutils instead of lld or bfd. + use_gold = !use_lld && !(is_chromecast && is_linux && + (target_cpu == "arm" || target_cpu == "mipsel")) && + (((is_linux || is_chromeos_lacros) && + (target_cpu == "x64" || target_cpu == "x86" || + target_cpu == "arm" || target_cpu == "arm64" || + target_cpu == "mipsel" || target_cpu == "mips64el")) || + (is_android && (target_cpu == "x86" || target_cpu == "x64" || + target_cpu == "arm" || target_cpu == "arm64"))) +} + +# Use relative paths for debug info. This is important to make the build +# results independent of the checkout and build directory names, which +# in turn is important for goma compile hit rate. +# Setting this to true may make it harder to debug binaries on Linux, see +# https://chromium.googlesource.com/chromium/src/+/main/docs/linux/debugging.md#Source-level-debug-with-fdebug_compilation_dir +# It's not clear if the crash server will correctly handle dSYMs with relative +# paths, so we disable this feature for official benefit. The main benefit is +# deterministic builds to reduce compile times, so this is less relevant for +# official builders. +strip_absolute_paths_from_debug_symbols_default = + is_android || is_fuchsia || is_nacl || (is_win && use_lld) || is_linux || + is_chromeos || (is_apple && !enable_dsyms) + +# If the platform uses stripped absolute paths by default, then we don't expose +# it as a configuration option. If this is causing problems, please file a bug. +if (strip_absolute_paths_from_debug_symbols_default) { + strip_absolute_paths_from_debug_symbols = true +} else { + declare_args() { + strip_absolute_paths_from_debug_symbols = false + } +} + +# If it wasn't manually set, then default use_debug_fission to false. +assert( + use_debug_fission == "default" || use_debug_fission || !use_debug_fission, + "Invalid use_debug_fission.") +if (use_debug_fission == "default") { + use_debug_fission = is_debug && !is_android && !is_fuchsia && !is_apple && + !is_win && (use_gold || use_lld) && cc_wrapper == "" +} + +# If it wasn't manually set, set to an appropriate default. +assert(symbol_level >= -1 && symbol_level <= 2, "Invalid symbol_level") +if (symbol_level == -1) { + if (is_android && !is_component_build && !use_debug_fission) { + # Reduce symbol level when it will cause invalid elf files to be created + # (due to file size). https://crbug.com/648948. + symbol_level = 1 + } else if (is_chromeos_device) { + # Use lower symbol level in Simple Chrome build for faster link time. + # For Simple Chrome, this should take precedence over is_official_build, + # turned on by --internal. + if ((target_cpu == "x64" || target_cpu == "x86") && !is_debug) { + # For release x86/x64 build, specify symbol_level=0 for faster link time. + # x86/x64 shows backtraces with symbol_level=0 (arm requires + # symbol_level=1). + symbol_level = 0 + } else { + symbol_level = 1 + } + } else if (using_sanitizer) { + # Sanitizers need line table info for stack traces. They don't need type + # info or variable info, so we can leave that out to speed up the build. + # Sanitizers also require symbols for filename suppressions to work. + symbol_level = 1 + } else if ((!is_nacl && !is_linux && !is_chromeos && !is_fuchsia && + current_os != "aix") || is_debug || is_official_build || + is_chromecast) { + # Linux builds slower by having symbols as part of the target binary, + # whereas Mac and Windows have them separate, so in Release Linux, default + # them off, but keep them on for Official builds and Chromecast builds. + symbol_level = 2 + } else { + symbol_level = 0 + } +} + +# Split dwarf works only for symbol_level == 2. +use_debug_fission = use_debug_fission && symbol_level == 2 + +# Non-component debug builds with symbol_level = 2 are an undesirable (very slow +# build times) and unsupported (some test binaries will fail with > 4 GB PDBs) +# combination. This is only checked when current_toolchain == default_toolchain +# because the is_component_build flag is set to false in various components of +# the build (like nacl) and we don't want to assert on those. +# iOS does not support component builds so add an exception for this platform. +if (forbid_non_component_debug_builds) { + assert(symbol_level != 2 || current_toolchain != default_toolchain || + is_component_build || !is_debug || is_ios, + "Can't do non-component debug builds at symbol_level=2") +} + +# Assert that the configuration isn't going to hit https://crbug.com/648948. +# An exception is made when target_os == "chromeos" as we only use the Android +# toolchain there to build relatively small binaries. +assert( + ignore_elf32_limitations || !is_android || target_os == "chromeos" || + is_component_build || symbol_level < 2 || use_debug_fission || + (android_64bit_target_cpu && skip_secondary_abi_for_cq), + "Android 32-bit non-component builds without DWARF Fission cannot " + + "have symbol_level=2 due to 4GiB file size limit, see " + + "https://crbug.com/648948. " + "If you really want to try this out, " + + "set ignore_elf32_limitations=true.") |