src/utils/BUILD.gn - dawn.git - Git at Google

 # Copyright 2024 The Dawn & Tint Authors
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are met:
 #
 # 1. Redistributions of source code must retain the above copyright notice, this
 #    list of conditions and the following disclaimer.
 #
 # 2. Redistributions in binary form must reproduce the above copyright notice,
 #    this list of conditions and the following disclaimer in the documentation
 #    and/or other materials provided with the distribution.
 #
 # 3. Neither the name of the copyright holder nor the names of its
 #    contributors may be used to endorse or promote products derived from
 #    this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 # DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 ###############################################################################
 # Utils library
 ###############################################################################

 import("../../scripts/dawn_features.gni")
 import("../../scripts/dawn_overrides_with_defaults.gni")

 import("//build_overrides/build.gni")
 import("${dawn_root}/scripts/dawn_nocompile.gni")

 # Use Chromium's dcheck_always_on when available so that we respect it when
 # running tests on the GPU builders
 if (build_with_chromium) {
   import("//build/config/dcheck_always_on.gni")
 } else {
   dcheck_always_on = false
 }

 if (build_with_chromium) {
   import("//build/config/sanitizers/sanitizers.gni")
 } else {
   use_fuzzing_engine = false
 }

 # Centralized config for -Weverything and its suppressions.
 #
 # Notes:
 # - File-specific warning suppressions can't be specified as cflags in a GN
 #   target, and must be specified in warning_suppression_mappings.txt. This is
 #   due to GN's flag ordering rules which specify that configs' cflags come
 #   after target cflags:
 #   https://gn.googlesource.com/gn/+/main/docs/faq.md#What-is-the-order-of-flags-and-values-given-to-the-compiler
 # - This is not the only source of warning configs. GN also has default warning
 #   configs in //build/config/BUILDCONFIG.gn (which we include from our .gn).
 config("dawn_warnings") {
   cflags = []
   cflags_c = []
   cflags_cc = []

   if (dawn_weverything) {
     assert(dawn_standalone && is_clang,
            "dawn_weverything requires clang in a standalone build.")
   }

   # If we're not using Clang, then we don't touch any warning config.
   if (is_clang) {
     ### In dawn_standalone, first, enable the base set of warnings.
     if (dawn_standalone) {
       if (dawn_weverything) {
         cflags += [
           "-Weverything",

           # Re-enable (almost) all the warnings that are mentioned in
           # //build/config/compiler/BUILD.gn to try to reset any disabled
           # warnings as -Weverything won't override previous -Wno-* flags. They
           # may be re-disabled subsequently, this is just to set a baseline.
           "-Wbackend-plugin",
           "-Wc++11-narrowing",
           "-Wcast-function-type",
           "-Wcomments",
           "-Wdeprecated-builtins",
           "-Wdeprecated-declarations",
           "-Wexit-time-destructors",
           "-Wgnu-anonymous-struct",
           "-Wgnu-case-range",
           "-Wgnu-conditional-omitted-operand",
           "-Wgnu-include-next",
           "-Wgnu-label-as-value",
           "-Wgnu-line-marker",
           "-Wgnu-offsetof-extensions",
           "-Wgnu-redeclared-enum",
           "-Wgnu-statement-expression",
           "-Wgnu-zero-variadic-macro-arguments",
           "-Wincompatible-pointer-types",
           "-Wmissing-field-initializers",
           "-Wnarrowing",
           "-Wnonportable-include-path",
           "-Wnontrivial-memcall",
           "-Wpsabi",
           "-Wthread-safety-reference-return",
           "-Wuninitialized-const-pointer",
           "-Wunnecessary-virtual-specifier",
           "-Wunneeded-internal-declaration",
           "-Wunsafe-buffer-usage-in-static-sized-array",
           "-Wunused-but-set-global",
           "-Wunused-but-set-variable",
           "-Wunused-function",
           "-Wunused-local-typedefs",
           "-Wunused-parameter",
           "-Wunused-variable",
           "-Wzero-length-array",
         ]

         # Same but for things passed in cflags_cc as those will be placed on
         # the command line after ALL the cflags.
         cflags_cc += [
           "-Winvalid-offsetof",
           "-Wmodule-import-in-extern-c",
           "-Wmodules-ambiguous-internal-linkage",
           "-Wmodules-import-nested-redundant",
           "-Wnarrowing",
           "-Wtrigraphs",
           "-Wnullability-completeness",
           "-Wdeprecated-builtins",
           "-Wc++98-compat-extra-semi",
         ]

         # Treat third_party and gen headers as system headers to suppress
         # warnings. The path needs to be the literal beginning of the string in
         # the #include directive, so include path resolving to different names
         # is added separately.
         #
         # This is only applied when dawn_standalone. Chromium build has
         # system_headers_in_deps = false by default.
         #
         # TODO(https://crbug.com/523358231): For dependencies whose code ends up in
         # Dawn, we should try suppressing individual warnings more specifically
         # using warning_suppression_mappings.txt.
         _prefixes = [
           "third_party/",
           "absl/",
           "benchmark/",
           "glslang/",
           "gmock/",
           "KHR/",
           "partition_alloc/",
           "napi.h",
           "testing/",
           "vulkan/",

           # TODO(crbug.com/523358231): It's good to enable warnings for
           # generated code. Currently, removing this results in many warnings in
           # generated webgpu_cpp.h.
           "dawn/webgpu_cpp.h",
           "webgpu/webgpu_cpp.h",

           # Also include headers from prebuilt third_party libraries, such as
           # agility-sdk.
           "d3d12.h",
         ]
         foreach(_prefix, _prefixes) {
           # Prefix with -Xclang so this will be accepted by both clang-cl and
           # clang.
           cflags += [ "-Xclang=--system-header-prefix=${_prefix}" ]
         }
       } else {
         cflags = [
           "-Wall",
           "-Wextra",
           "-Wpedantic",

           # Additional warnings that are not part of -Wall or -Wextra.
           "-Wconditional-uninitialized",
           "-Wcstring-format-directive",
           "-Wctad-maybe-unsupported",
           "-Wc++11-narrowing",
           "-Wdeprecated-copy",
           "-Wdeprecated-copy-dtor",
           "-Wduplicate-enum",
           "-Wextra-semi",
           "-Wextra-semi-stmt",
           "-Wimplicit-fallthrough",
           "-Winconsistent-missing-destructor-override",
           "-Winvalid-offsetof",
           "-Wmissing-field-initializers",
           "-Wnon-c-typedef-for-linkage",
           "-Wpessimizing-move",
           "-Wrange-loop-analysis",
           "-Wredundant-move",
           "-Wshadow-field",
           "-Wstrict-prototypes",
           "-Wsuggest-destructor-override",
           "-Wsuggest-override",
           "-Wtautological-unsigned-zero-compare",
           "-Wunreachable-code-aggressive",
           "-Wunused-but-set-variable",
           "-Wunused-macros",
         ]

         cflags_cc = []
       }
     }

     ### Now, configure all warning suppressions (regardless of dawn_standalone).

     # Use per-file warning suppressions from warning_suppression_mappings.txt
     inputs = [ "warning_suppression_mappings.txt" ]
     cflags +=
         [ "--warning-suppression-mappings=" +
           rebase_path("warning_suppression_mappings.txt", root_build_dir) ]

     if (!clang_use_unsafe_buffers_plugin) {
       # If we don't have Chromium's unsafe buffers plugin (e.g. it was
       # disabled in GN args), disable the warning entirely. The plugin
       # implements unsafe_buffers_paths.txt support, and probably other
       # important things we don't want to run without.
       cflags += [ "-Wno-unsafe-buffer-usage" ]
     }

     # TODO(https://crbug.com/523358231): Enable more warnings.

     # P0. Most likely to help with hardening.
     cflags += [
       # Arithmetic
       "-Wno-implicit-float-conversion",
       "-Wno-implicit-int-conversion",
       "-Wno-sign-conversion",
     ]

     # P1. Likely to help with hardening.
     cflags += [
       # Thread safety (https://crbug.com/529895490)
       "-Wno-thread-safety",

       # Enums (https://crbug.com/515562283)
       "-Wno-switch-default",
       "-Wno-switch-enum",
     ]

     # P2. Might help with hardening.
     cflags += [
       "-Wno-float-equal",
       "-Wno-non-virtual-dtor",
       "-Wno-undefined-func-template",
       "-Wno-unused-parameter",

       # The lifetime-safety-* warnings are part of an experimental analysis.
       # Many individual diagnostics (like
       # -Wlifetime-safety-lifetimebound-violation) are not yet mapped to
       # toggleable warning flags, so we suppress the entire group and disable
       # the analysis pass.
       "-Wno-lifetime-safety",
       "-Wno-lifetime-safety-all",
       "-Xclang=-fno-lifetime-safety-inference",
       "-Xclang=-fno-experimental-lifetime-safety-tu-analysis",
     ]

     # P3. Checks that could be nice but probably don't help with hardening.
     cflags += [
       "-Wno-unused-member-function",
       "-Wno-unused-template",

       # Performance
       "-Wno-exit-time-destructors",
       "-Wno-global-constructors",
       "-Wno-nrvo",
       "-Wno-weak-vtables",
     ]

     # P4. Checks we might want to look at again someday.
     cflags += [
       "-Wno-documentation",
       "-Wno-nonportable-system-include-path",

       # Needed for __COUNTER__ in various Tint and platform macros.
       "-Wno-c2y-extensions",

       # Disallows `default:` in switches that appear to be covered. Our switches
       # are rarely actually covered. Note, crbug.com/515562283 may change this.
       "-Wno-covered-switch-default",

       # Dawn codebase codebase mostly lives without any nullability checks. Few
       # obscure cases like `std::string{[NSString UTF8String])` are not worth
       # changing.
       "-Wno-nullable-to-nonnull-conversion",

       # Disallows multiple header file candidates.
       # Dawn and Tint have many headers that are mirrored between the source and
       # generated files directories while they are the same file.
       "-Wno-shadow-header",
     ]

     # P∞. Checks we're not really interested in re-enabling.
     cflags += [
       # We require C++20.
       "-Wno-c++20-extensions",
       "-Wno-c++98-compat",
       "-Wno-c++98-compat-pedantic",
       "-Wno-pre-c++14-compat",
       "-Wno-pre-c++17-compat",
       "-Wno-pre-c++20-compat",

       # Misc.
       "-Wno-missing-designated-field-initializers",
       "-Wno-missing-prototypes",
       "-Wno-padded",

       # Triggers on system header stuff like `stdout`.
       "-Wno-disabled-macro-expansion",

       # Needed for libc++ and GL, not really useful to us.
       "-Wno-reserved-identifier",

       # Shadow warnings that would require confusing variable renames.
       "-Wno-shadow-field-in-constructor",
       "-Wno-shadow-uncaptured-local",

       # This warning tries to prove that the expression passed to
       # __builtin_assume (DAWN_RELEASE_ASSUME) has no side effects, because that
       # expression does not get executed. But its analysis is too simple to be
       # useful - it triggers too often (e.g. on std::numeric_limits::max()).
       # Instead we use clang-tidy's heuristic `bugprone-assert-side-effect`.
       "-Wno-assume",

       # Disallows comparison result always true. We have branches that can be
       # always true on some platforms but not on other platforms (e.g. x86, x64)
       "-Wno-tautological-type-limit-compare",

       # WGSL uses @ as part of its attribute syntax and it vastly appears in
       # Tint comments, while clang uses @ to mark a documentation command in the
       # comment.
       "-Wno-documentation-unknown-command",
     ]
   }

   cflags_objc = cflags_c
   cflags_objcc = cflags_cc
 }

 # TODO(crbug.com/523358231): Some targets pick up this config multiple times and
 # receive all of the warning flags repeatedly, for example they're repeated
 # three times in obj/src/dawn/native/sources/Device.o. Can this be avoided?
 config("internal_config") {
   include_dirs = [ "${dawn_root}" ]

   defines = []
   configs = [ ":dawn_warnings" ]

   if (is_clang && dawn_standalone && !is_wasm) {
     configs += [ ":raw_ptr_check" ]
   }

   if (dawn_always_assert || dcheck_always_on || is_debug ||
       use_fuzzing_engine) {
     defines += [ "DAWN_ENABLE_ASSERTS" ]
   }

   if (build_with_chromium || use_fuzzing_engine) {
     # Does a hard abort when an assertion fails so that fuzzers catch and parse
     # the failure. Also call abort() so chrome can dump crash stack in console.
     defines += [ "DAWN_ABORT_ON_ASSERT" ]
   }

   if (use_fuzzing_engine) {
     # Disable logging to make fuzzing more efficient.
     defines += [ "DAWN_DISABLE_LOGGING" ]
   }

   # OS_CHROMEOS cannot be autodetected in runtime and
   # cannot be detected with regular compiler macros either.
   # Inject it from the build system
   if (is_chromeos) {
     defines += [ "DAWN_OS_CHROMEOS" ]
   }
 }

 static_library("utils") {
   sources = [
     "assert.cc",
     "assert.h",
     "compiler.h",
     "force_crash.h",
     "heap_array.h",
     "log.cc",
     "log.h",
     "non_copyable.h",
     "non_movable.h",
     "numeric.h",
     "placeholder.cc",
     "platform.h",
     "span.h",
     "typed_integer.h",
     "underlying_type.h",
   ]

   if (is_win) {
     sources += [ "windows_with_undefs.h" ]
   }

   public_configs = [ ":internal_config" ]
 }

 source_set("crash_handler") {
   sources = [
     "crash_handler.cc",
     "crash_handler.h",
   ]
   public_configs = [ ":internal_config" ]
   public_deps = [ "${dawn_abseil_dir}:absl" ]
 }

 dawn_nocompile_source_set("nocompile_sources") {
   deps = [ ":utils" ]
   sources = [
     "heap_array_nocompile.nc",
     "numeric_nocompile.nc",
     "span_nocompile.nc",
     "typed_integer_nocompile.nc",
   ]
   if (dawn_weverything) {
     sources += [ "warning_nocompile.nc" ]
   }
 }

 # Included in dawn_unittests.
 source_set("unittests") {
   testonly = true

   deps = [
     ":gmock_and_gtest",
     ":nocompile_sources",
     ":utils",
     "${dawn_root}/src/dawn/partition_alloc:raw_ptr",
   ]

   sources = [
     "assert_test.cc",
     "heap_array_test.cc",
     "numeric_test.cc",
     "span_tests.cc",
     "typed_integer_tests.cc",
     "underlying_type_tests.cc",
   ]
 }

 ###############################################################################
 # Gtest Gmock - Handle building inside and outside of Chromium.
 ###############################################################################

 # When building outside of Chromium we need to define our own targets for GTest
 # and GMock. However when compiling inside of Chromium we need to reuse the
 # existing targets, both because Chromium has a special harness for swarming
 # and because otherwise the "gn check" fails.

 if (build_with_chromium) {
   # When we are in Chromium we reuse its targets, and also add some deps that
   # are needed to launch the test in swarming mode.
   group("gmock_and_gtest_only") {
     testonly = true
     public_deps = [
       "//base",
       "//base/test:test_support",
       "//testing/gmock",
       "//testing/gtest",
     ]
   }
 } else {
   # When we aren't in Chromium we define out own targets based on the location
   # of the googletest repo.
   googletest_dir = dawn_googletest_dir

   config("gtest_config") {
     include_dirs = [
       "${googletest_dir}/googletest",
       "${googletest_dir}/googletest/include",
     ]
   }

   static_library("gtest") {
     testonly = true
     sources = [ "${googletest_dir}/googletest/src/gtest-all.cc" ]
     public_configs = [ ":gtest_config" ]
   }

   config("gmock_config") {
     include_dirs = [
       "${googletest_dir}/googlemock",
       "${googletest_dir}/googlemock/include",
       "${googletest_dir}/googletest/include",
     ]
     if (dawn_standalone && is_clang) {
       cflags = [
         # gmock emits deprecated-copy-dtor warnings when using
         # ::testing::Combine
         "-Wno-deprecated-copy-dtor",
       ]
     }
   }

   static_library("gmock") {
     testonly = true
     sources = [ "${googletest_dir}/googlemock/src/gmock-all.cc" ]
     public_configs = [ ":gmock_config" ]
   }

   group("gmock_and_gtest_only") {
     testonly = true
     public_deps = [
       ":gmock",
       ":gtest",
     ]
   }

   static_library("gmock_main") {
     testonly = true
     sources = [ "${googletest_dir}/googlemock/src/gmock_main.cc" ]
     public_deps = [ ":gmock_and_gtest_only" ]
   }
 }

 source_set("gmock_and_gtest") {
   testonly = true
   public_deps = [ ":gmock_and_gtest_only" ]
   deps = [ ":utils" ]

   # Dawn's gtest utils.
   sources = [ "gtest.h" ]
 }

 ###############################################################################
 # Additional clang plugins.
 ###############################################################################

 # Helper template to define clang plugins.
 #
 # Params:
 #   plugin: The name of the clang plugin to load.
 #   plugin_arguments: List of arguments to pass to the plugin.
 template("clang_plugin") {
   config(target_name) {
     cflags = [
       "-Xclang=-add-plugin",
       "-Xclang=${invoker.plugin}",
     ]

     foreach(flag, invoker.plugin_arguments) {
       cflags += [
         "-Xclang=-plugin-arg-${invoker.plugin}",
         "-Xclang=${flag}",
       ]
     }
   }
 }

 # Check struct/class member pointers are using raw_ptr<> where appropriate.
 clang_plugin("raw_ptr_check") {
   # Defined in <chromium>/tools/clang/raw_ptr_plugin/RawPtrPlugin.cpp
   plugin = "raw-ptr-plugin"

   plugin_arguments = [
     "check-raw-ptr-fields",
     "check-raw-ptr-to-stack-allocated",
     "check-raw-ref-fields",
     "check-span-fields",
   ]

   _exclusions = [
     "/include/",
     "/src/tint/",
     "/src/dawn/replay/",

     # TODO(https://crbug.com/479743213): Enforce raw_ptr usage in dawn/node.
     "/src/dawn/node/",
   ]

   foreach(dir, _exclusions) {
     plugin_arguments += [ "raw-ptr-exclude-path=" +
                           rebase_path("${dawn_root}/${dir}", root_build_dir) ]
   }
 }
	# Copyright 2024 The Dawn & Tint Authors
	#
	# Redistribution and use in source and binary forms, with or without
	# modification, are permitted provided that the following conditions are met:
	#
	# 1. Redistributions of source code must retain the above copyright notice, this
	# list of conditions and the following disclaimer.
	#
	# 2. Redistributions in binary form must reproduce the above copyright notice,
	# this list of conditions and the following disclaimer in the documentation
	# and/or other materials provided with the distribution.
	#
	# 3. Neither the name of the copyright holder nor the names of its
	# contributors may be used to endorse or promote products derived from
	# this software without specific prior written permission.
	#
	# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
	# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	###############################################################################
	# Utils library
	###############################################################################

	import("../../scripts/dawn_features.gni")
	import("../../scripts/dawn_overrides_with_defaults.gni")

	import("//build_overrides/build.gni")
	import("${dawn_root}/scripts/dawn_nocompile.gni")

	# Use Chromium's dcheck_always_on when available so that we respect it when
	# running tests on the GPU builders
	if (build_with_chromium) {
	import("//build/config/dcheck_always_on.gni")
	} else {
	dcheck_always_on = false
	}

	if (build_with_chromium) {
	import("//build/config/sanitizers/sanitizers.gni")
	} else {
	use_fuzzing_engine = false
	}

	# Centralized config for -Weverything and its suppressions.
	#
	# Notes:
	# - File-specific warning suppressions can't be specified as cflags in a GN
	# target, and must be specified in warning_suppression_mappings.txt. This is
	# due to GN's flag ordering rules which specify that configs' cflags come
	# after target cflags:
	# https://gn.googlesource.com/gn/+/main/docs/faq.md#What-is-the-order-of-flags-and-values-given-to-the-compiler
	# - This is not the only source of warning configs. GN also has default warning
	# configs in //build/config/BUILDCONFIG.gn (which we include from our .gn).
	config("dawn_warnings") {
	cflags = []
	cflags_c = []
	cflags_cc = []

	if (dawn_weverything) {
	assert(dawn_standalone && is_clang,
	"dawn_weverything requires clang in a standalone build.")
	}

	# If we're not using Clang, then we don't touch any warning config.
	if (is_clang) {
	### In dawn_standalone, first, enable the base set of warnings.
	if (dawn_standalone) {
	if (dawn_weverything) {
	cflags += [
	"-Weverything",

	# Re-enable (almost) all the warnings that are mentioned in
	# //build/config/compiler/BUILD.gn to try to reset any disabled
	# warnings as -Weverything won't override previous -Wno-* flags. They
	# may be re-disabled subsequently, this is just to set a baseline.
	"-Wbackend-plugin",
	"-Wc++11-narrowing",
	"-Wcast-function-type",
	"-Wcomments",
	"-Wdeprecated-builtins",
	"-Wdeprecated-declarations",
	"-Wexit-time-destructors",
	"-Wgnu-anonymous-struct",
	"-Wgnu-case-range",
	"-Wgnu-conditional-omitted-operand",
	"-Wgnu-include-next",
	"-Wgnu-label-as-value",
	"-Wgnu-line-marker",
	"-Wgnu-offsetof-extensions",
	"-Wgnu-redeclared-enum",
	"-Wgnu-statement-expression",
	"-Wgnu-zero-variadic-macro-arguments",
	"-Wincompatible-pointer-types",
	"-Wmissing-field-initializers",
	"-Wnarrowing",
	"-Wnonportable-include-path",
	"-Wnontrivial-memcall",
	"-Wpsabi",
	"-Wthread-safety-reference-return",
	"-Wuninitialized-const-pointer",
	"-Wunnecessary-virtual-specifier",
	"-Wunneeded-internal-declaration",
	"-Wunsafe-buffer-usage-in-static-sized-array",
	"-Wunused-but-set-global",
	"-Wunused-but-set-variable",
	"-Wunused-function",
	"-Wunused-local-typedefs",
	"-Wunused-parameter",
	"-Wunused-variable",
	"-Wzero-length-array",
	]

	# Same but for things passed in cflags_cc as those will be placed on
	# the command line after ALL the cflags.
	cflags_cc += [
	"-Winvalid-offsetof",
	"-Wmodule-import-in-extern-c",
	"-Wmodules-ambiguous-internal-linkage",
	"-Wmodules-import-nested-redundant",
	"-Wnarrowing",
	"-Wtrigraphs",
	"-Wnullability-completeness",
	"-Wdeprecated-builtins",
	"-Wc++98-compat-extra-semi",
	]

	# Treat third_party and gen headers as system headers to suppress
	# warnings. The path needs to be the literal beginning of the string in
	# the #include directive, so include path resolving to different names
	# is added separately.
	#
	# This is only applied when dawn_standalone. Chromium build has
	# system_headers_in_deps = false by default.
	#
	# TODO(https://crbug.com/523358231): For dependencies whose code ends up in
	# Dawn, we should try suppressing individual warnings more specifically
	# using warning_suppression_mappings.txt.
	_prefixes = [
	"third_party/",
	"absl/",
	"benchmark/",
	"glslang/",
	"gmock/",
	"KHR/",
	"partition_alloc/",
	"napi.h",
	"testing/",
	"vulkan/",

	# TODO(crbug.com/523358231): It's good to enable warnings for
	# generated code. Currently, removing this results in many warnings in
	# generated webgpu_cpp.h.
	"dawn/webgpu_cpp.h",
	"webgpu/webgpu_cpp.h",

	# Also include headers from prebuilt third_party libraries, such as
	# agility-sdk.
	"d3d12.h",
	]
	foreach(_prefix, _prefixes) {
	# Prefix with -Xclang so this will be accepted by both clang-cl and
	# clang.
	cflags += [ "-Xclang=--system-header-prefix=${_prefix}" ]
	}
	} else {
	cflags = [
	"-Wall",
	"-Wextra",
	"-Wpedantic",

	# Additional warnings that are not part of -Wall or -Wextra.
	"-Wconditional-uninitialized",
	"-Wcstring-format-directive",
	"-Wctad-maybe-unsupported",
	"-Wc++11-narrowing",
	"-Wdeprecated-copy",
	"-Wdeprecated-copy-dtor",
	"-Wduplicate-enum",
	"-Wextra-semi",
	"-Wextra-semi-stmt",
	"-Wimplicit-fallthrough",
	"-Winconsistent-missing-destructor-override",
	"-Winvalid-offsetof",
	"-Wmissing-field-initializers",
	"-Wnon-c-typedef-for-linkage",
	"-Wpessimizing-move",
	"-Wrange-loop-analysis",
	"-Wredundant-move",
	"-Wshadow-field",
	"-Wstrict-prototypes",
	"-Wsuggest-destructor-override",
	"-Wsuggest-override",
	"-Wtautological-unsigned-zero-compare",
	"-Wunreachable-code-aggressive",
	"-Wunused-but-set-variable",
	"-Wunused-macros",
	]

	cflags_cc = []
	}
	}

	### Now, configure all warning suppressions (regardless of dawn_standalone).

	# Use per-file warning suppressions from warning_suppression_mappings.txt
	inputs = [ "warning_suppression_mappings.txt" ]
	cflags +=
	[ "--warning-suppression-mappings=" +
	rebase_path("warning_suppression_mappings.txt", root_build_dir) ]

	if (!clang_use_unsafe_buffers_plugin) {
	# If we don't have Chromium's unsafe buffers plugin (e.g. it was
	# disabled in GN args), disable the warning entirely. The plugin
	# implements unsafe_buffers_paths.txt support, and probably other
	# important things we don't want to run without.
	cflags += [ "-Wno-unsafe-buffer-usage" ]
	}

	# TODO(https://crbug.com/523358231): Enable more warnings.

	# P0. Most likely to help with hardening.
	cflags += [
	# Arithmetic
	"-Wno-implicit-float-conversion",
	"-Wno-implicit-int-conversion",
	"-Wno-sign-conversion",
	]

	# P1. Likely to help with hardening.
	cflags += [
	# Thread safety (https://crbug.com/529895490)
	"-Wno-thread-safety",

	# Enums (https://crbug.com/515562283)
	"-Wno-switch-default",
	"-Wno-switch-enum",
	]

	# P2. Might help with hardening.
	cflags += [
	"-Wno-float-equal",
	"-Wno-non-virtual-dtor",
	"-Wno-undefined-func-template",
	"-Wno-unused-parameter",

	# The lifetime-safety-* warnings are part of an experimental analysis.
	# Many individual diagnostics (like
	# -Wlifetime-safety-lifetimebound-violation) are not yet mapped to
	# toggleable warning flags, so we suppress the entire group and disable
	# the analysis pass.
	"-Wno-lifetime-safety",
	"-Wno-lifetime-safety-all",
	"-Xclang=-fno-lifetime-safety-inference",
	"-Xclang=-fno-experimental-lifetime-safety-tu-analysis",
	]

	# P3. Checks that could be nice but probably don't help with hardening.
	cflags += [
	"-Wno-unused-member-function",
	"-Wno-unused-template",

	# Performance
	"-Wno-exit-time-destructors",
	"-Wno-global-constructors",
	"-Wno-nrvo",
	"-Wno-weak-vtables",
	]

	# P4. Checks we might want to look at again someday.
	cflags += [
	"-Wno-documentation",
	"-Wno-nonportable-system-include-path",

	# Needed for __COUNTER__ in various Tint and platform macros.
	"-Wno-c2y-extensions",

	# Disallows `default:` in switches that appear to be covered. Our switches
	# are rarely actually covered. Note, crbug.com/515562283 may change this.
	"-Wno-covered-switch-default",

	# Dawn codebase codebase mostly lives without any nullability checks. Few
	# obscure cases like `std::string{[NSString UTF8String])` are not worth
	# changing.
	"-Wno-nullable-to-nonnull-conversion",

	# Disallows multiple header file candidates.
	# Dawn and Tint have many headers that are mirrored between the source and
	# generated files directories while they are the same file.
	"-Wno-shadow-header",
	]

	# P∞. Checks we're not really interested in re-enabling.
	cflags += [
	# We require C++20.
	"-Wno-c++20-extensions",
	"-Wno-c++98-compat",
	"-Wno-c++98-compat-pedantic",
	"-Wno-pre-c++14-compat",
	"-Wno-pre-c++17-compat",
	"-Wno-pre-c++20-compat",

	# Misc.
	"-Wno-missing-designated-field-initializers",
	"-Wno-missing-prototypes",
	"-Wno-padded",

	# Triggers on system header stuff like `stdout`.
	"-Wno-disabled-macro-expansion",

	# Needed for libc++ and GL, not really useful to us.
	"-Wno-reserved-identifier",

	# Shadow warnings that would require confusing variable renames.
	"-Wno-shadow-field-in-constructor",
	"-Wno-shadow-uncaptured-local",

	# This warning tries to prove that the expression passed to
	# __builtin_assume (DAWN_RELEASE_ASSUME) has no side effects, because that
	# expression does not get executed. But its analysis is too simple to be
	# useful - it triggers too often (e.g. on std::numeric_limits::max()).
	# Instead we use clang-tidy's heuristic `bugprone-assert-side-effect`.
	"-Wno-assume",

	# Disallows comparison result always true. We have branches that can be
	# always true on some platforms but not on other platforms (e.g. x86, x64)
	"-Wno-tautological-type-limit-compare",

	# WGSL uses @ as part of its attribute syntax and it vastly appears in
	# Tint comments, while clang uses @ to mark a documentation command in the
	# comment.
	"-Wno-documentation-unknown-command",
	]
	}

	cflags_objc = cflags_c
	cflags_objcc = cflags_cc
	}

	# TODO(crbug.com/523358231): Some targets pick up this config multiple times and
	# receive all of the warning flags repeatedly, for example they're repeated
	# three times in obj/src/dawn/native/sources/Device.o. Can this be avoided?
	config("internal_config") {
	include_dirs = [ "${dawn_root}" ]

	defines = []
	configs = [ ":dawn_warnings" ]

	if (is_clang && dawn_standalone && !is_wasm) {
	configs += [ ":raw_ptr_check" ]
	}

	if (dawn_always_assert \|\| dcheck_always_on \|\| is_debug \|\|
	use_fuzzing_engine) {
	defines += [ "DAWN_ENABLE_ASSERTS" ]
	}

	if (build_with_chromium \|\| use_fuzzing_engine) {
	# Does a hard abort when an assertion fails so that fuzzers catch and parse
	# the failure. Also call abort() so chrome can dump crash stack in console.
	defines += [ "DAWN_ABORT_ON_ASSERT" ]
	}

	if (use_fuzzing_engine) {
	# Disable logging to make fuzzing more efficient.
	defines += [ "DAWN_DISABLE_LOGGING" ]
	}

	# OS_CHROMEOS cannot be autodetected in runtime and
	# cannot be detected with regular compiler macros either.
	# Inject it from the build system
	if (is_chromeos) {
	defines += [ "DAWN_OS_CHROMEOS" ]
	}
	}

	static_library("utils") {
	sources = [
	"assert.cc",
	"assert.h",
	"compiler.h",
	"force_crash.h",
	"heap_array.h",
	"log.cc",
	"log.h",
	"non_copyable.h",
	"non_movable.h",
	"numeric.h",
	"placeholder.cc",
	"platform.h",
	"span.h",
	"typed_integer.h",
	"underlying_type.h",
	]

	if (is_win) {
	sources += [ "windows_with_undefs.h" ]
	}

	public_configs = [ ":internal_config" ]
	}

	source_set("crash_handler") {
	sources = [
	"crash_handler.cc",
	"crash_handler.h",
	]
	public_configs = [ ":internal_config" ]
	public_deps = [ "${dawn_abseil_dir}:absl" ]
	}

	dawn_nocompile_source_set("nocompile_sources") {
	deps = [ ":utils" ]
	sources = [
	"heap_array_nocompile.nc",
	"numeric_nocompile.nc",
	"span_nocompile.nc",
	"typed_integer_nocompile.nc",
	]
	if (dawn_weverything) {
	sources += [ "warning_nocompile.nc" ]
	}
	}

	# Included in dawn_unittests.
	source_set("unittests") {
	testonly = true

	deps = [
	":gmock_and_gtest",
	":nocompile_sources",
	":utils",
	"${dawn_root}/src/dawn/partition_alloc:raw_ptr",
	]

	sources = [
	"assert_test.cc",
	"heap_array_test.cc",
	"numeric_test.cc",
	"span_tests.cc",
	"typed_integer_tests.cc",
	"underlying_type_tests.cc",
	]
	}

	###############################################################################
	# Gtest Gmock - Handle building inside and outside of Chromium.
	###############################################################################

	# When building outside of Chromium we need to define our own targets for GTest
	# and GMock. However when compiling inside of Chromium we need to reuse the
	# existing targets, both because Chromium has a special harness for swarming
	# and because otherwise the "gn check" fails.

	if (build_with_chromium) {
	# When we are in Chromium we reuse its targets, and also add some deps that
	# are needed to launch the test in swarming mode.
	group("gmock_and_gtest_only") {
	testonly = true
	public_deps = [
	"//base",
	"//base/test:test_support",
	"//testing/gmock",
	"//testing/gtest",
	]
	}
	} else {
	# When we aren't in Chromium we define out own targets based on the location
	# of the googletest repo.
	googletest_dir = dawn_googletest_dir

	config("gtest_config") {
	include_dirs = [
	"${googletest_dir}/googletest",
	"${googletest_dir}/googletest/include",
	]
	}

	static_library("gtest") {
	testonly = true
	sources = [ "${googletest_dir}/googletest/src/gtest-all.cc" ]
	public_configs = [ ":gtest_config" ]
	}

	config("gmock_config") {
	include_dirs = [
	"${googletest_dir}/googlemock",
	"${googletest_dir}/googlemock/include",
	"${googletest_dir}/googletest/include",
	]
	if (dawn_standalone && is_clang) {
	cflags = [
	# gmock emits deprecated-copy-dtor warnings when using
	# ::testing::Combine
	"-Wno-deprecated-copy-dtor",
	]
	}
	}

	static_library("gmock") {
	testonly = true
	sources = [ "${googletest_dir}/googlemock/src/gmock-all.cc" ]
	public_configs = [ ":gmock_config" ]
	}

	group("gmock_and_gtest_only") {
	testonly = true
	public_deps = [
	":gmock",
	":gtest",
	]
	}

	static_library("gmock_main") {
	testonly = true
	sources = [ "${googletest_dir}/googlemock/src/gmock_main.cc" ]
	public_deps = [ ":gmock_and_gtest_only" ]
	}
	}

	source_set("gmock_and_gtest") {
	testonly = true
	public_deps = [ ":gmock_and_gtest_only" ]
	deps = [ ":utils" ]

	# Dawn's gtest utils.
	sources = [ "gtest.h" ]
	}

	###############################################################################
	# Additional clang plugins.
	###############################################################################

	# Helper template to define clang plugins.
	#
	# Params:
	# plugin: The name of the clang plugin to load.
	# plugin_arguments: List of arguments to pass to the plugin.
	template("clang_plugin") {
	config(target_name) {
	cflags = [
	"-Xclang=-add-plugin",
	"-Xclang=${invoker.plugin}",
	]

	foreach(flag, invoker.plugin_arguments) {
	cflags += [
	"-Xclang=-plugin-arg-${invoker.plugin}",
	"-Xclang=${flag}",
	]
	}
	}
	}

	# Check struct/class member pointers are using raw_ptr<> where appropriate.
	clang_plugin("raw_ptr_check") {
	# Defined in <chromium>/tools/clang/raw_ptr_plugin/RawPtrPlugin.cpp
	plugin = "raw-ptr-plugin"

	plugin_arguments = [
	"check-raw-ptr-fields",
	"check-raw-ptr-to-stack-allocated",
	"check-raw-ref-fields",
	"check-span-fields",
	]

	_exclusions = [
	"/include/",
	"/src/tint/",
	"/src/dawn/replay/",

	# TODO(https://crbug.com/479743213): Enforce raw_ptr usage in dawn/node.
	"/src/dawn/node/",
	]

	foreach(dir, _exclusions) {
	plugin_arguments += [ "raw-ptr-exclude-path=" +
	rebase_path("${dawn_root}/${dir}", root_build_dir) ]
	}
	}