# -*- bazel-starlark -*-
# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Siso config version of clang_code_coverage_wrapper.py"""
# LINT.IfChange
load("@builtin//struct.star", "module")
# Logics are copied from build/toolchain/clang_code_coverage_wrapper.py
# in ordre to strip coverage flags without process invocation.
# This is neceesary for Siso to send clang command to RBE without the wrapper and instrument file.
# Flags used to enable coverage instrumentation.
# Flags should be listed in the same order that they are added in
# build/config/coverage/BUILD.gn
_COVERAGE_FLAGS = [
"-fprofile-instr-generate",
"-fcoverage-mapping",
# Following experimental flags remove unused header functions from the
# coverage mapping data embedded in the test binaries, and the reduction
# of binary size enables building Chrome's large unit test targets on
# MacOS. Please refer to crbug.com/796290 for more details.
"-mllvm",
"-limited-coverage-experimental=true",
]
# Files that should not be built with coverage flags by default.
_DEFAULT_COVERAGE_EXCLUSION_LIST = []
# Map of exclusion lists indexed by target OS.
# If no target OS is defined, or one is defined that doesn't have a specific
# entry, use _DEFAULT_COVERAGE_EXCLUSION_LIST.
_COVERAGE_EXCLUSION_LIST_MAP = {
"android": [
# This file caused webview native library failed on arm64.
"../../device/gamepad/dualshock4_controller.cc",
],
"fuchsia": [
# TODO(crbug.com/1174725): These files caused clang to crash while
# compiling them.
"../../base/allocator/partition_allocator/src/partition_alloc/pcscan.cc",
"../../third_party/skia/src/core/SkOpts.cpp",
"../../third_party/skia/src/opts/SkOpts_hsw.cpp",
"../../third_party/skia/third_party/skcms/skcms.cc",
],
"linux": [
# These files caused a static initializer to be generated, which
# shouldn't.
# TODO(crbug.com/990948): Remove when the bug is fixed.
"../../chrome/browser/media/router/providers/cast/cast_internal_message_util.cc", #pylint: disable=line-too-long
"../../components/media_router/common/providers/cast/channel/cast_channel_enum.cc", #pylint: disable=line-too-long
"../../components/media_router/common/providers/cast/channel/cast_message_util.cc", #pylint: disable=line-too-long
"../../components/media_router/common/providers/cast/cast_media_source.cc", #pylint: disable=line-too-long
"../../ui/events/keycodes/dom/keycode_converter.cc",
],
"chromeos": [
# These files caused clang to crash while compiling them. They are
# excluded pending an investigation into the underlying compiler bug.
"../../third_party/webrtc/p2p/base/p2p_transport_channel.cc",
"../../third_party/icu/source/common/uts46.cpp",
"../../third_party/icu/source/common/ucnvmbcs.cpp",
"../../base/android/android_image_reader_compat.cc",
],
}
# Map of force lists indexed by target OS.
_COVERAGE_FORCE_LIST_MAP = {
# clang_profiling.cc refers to the symbol `__llvm_profile_dump` from the
# profiling runtime. In a partial coverage build, it is possible for a
# binary to include clang_profiling.cc but have no instrumented files, thus
# causing an unresolved symbol error because the profiling runtime will not
# be linked in. Therefore we force coverage for this file to ensure that
# any target that includes it will also get the profiling runtime.
"win": [r"..\..\base\test\clang_profiling.cc"],
# TODO(crbug.com/1141727) We're seeing runtime LLVM errors in mac-rel when
# no files are changed, so we suspect that this is similar to the other
# problem with clang_profiling.cc on Windows. The TODO here is to force
# coverage for this specific file on ALL platforms, if it turns out to fix
# this issue on Mac as well. It's the only file that directly calls
# `__llvm_profile_dump` so it warrants some special treatment.
"mac": ["../../base/test/clang_profiling.cc"],
}
def _remove_flags_from_command(command):
# We need to remove the coverage flags for this file, but we only want to
# remove them if we see the exact sequence defined in _COVERAGE_FLAGS.
# That ensures that we only remove the flags added by GN when
# "use_clang_coverage" is true. Otherwise, we would remove flags set by
# other parts of the build system.
start_flag = _COVERAGE_FLAGS[0]
num_flags = len(_COVERAGE_FLAGS)
start_idx = 0
def _start_flag_idx(cmd, start_idx):
for i in range(start_idx, len(cmd)):
if cmd[i] == start_flag:
return i
# Workaround to emulate while loop in Starlark.
for _ in range(0, len(command)):
idx = _start_flag_idx(command, start_idx)
if not idx:
# Coverage flags are not included anymore.
return command
if command[idx:idx + num_flags] == _COVERAGE_FLAGS:
# Starlark doesn't have `del`.
command = command[:idx] + command[idx + num_flags:]
# There can be multiple sets of _COVERAGE_FLAGS. All of these need to be
# removed.
start_idx = idx
else:
start_idx = idx + 1
return command
def __run(ctx, args):
"""Runs the main logic of clang_code_coverage_wrapper.
This is slightly different from the main function of clang_code_coverage_wrapper.py
because starlark can't use Python's standard libraries.
"""
# We need to remove the coverage flags for this file, but we only want to
# remove them if we see the exact sequence defined in _COVERAGE_FLAGS.
# That ensures that we only remove the flags added by GN when
# "use_clang_coverage" is true. Otherwise, we would remove flags set by
# other parts of the build system.
if len(args) == 0:
return args
if not args[0].endswith("python3") and not args[0].endswith("python3.exe"):
return args
has_coveage_wrapper = False
instrument_file = None
compile_command_pos = None
target_os = None
source_flag = "-c"
source_flag_index = None
for i, arg in enumerate(args):
if i == 0:
continue
if arg == "../../build/toolchain/clang_code_coverage_wrapper.py":
has_coveage_wrapper = True
continue
if arg.startswith("--files-to-instrument="):
instrument_file = arg.removeprefix("--files-to-instrument=")
continue
if arg.startswith("--target-os="):
target_os = arg.removeprefix("--target-os=")
if target_os == "win":
source_flag = "/c"
continue
if not compile_command_pos and not args[i].startswith("-") and "clang" in args[i]:
compile_command_pos = i
continue
if args[i] == source_flag:
# The command is assumed to use Clang as the compiler, and the path to the
# source file is behind the -c argument, and the path to the source path is
# relative to the root build directory. For example:
# clang++ -fvisibility=hidden -c ../../base/files/file_path.cc -o \
# obj/base/base/file_path.o
# On Windows, clang-cl.exe uses /c instead of -c.
source_flag_index = i
continue
if not has_coveage_wrapper or not compile_command_pos:
print("this is not clang coverage command. %s" % str(args))
return args
compile_command = args[compile_command_pos:]
if not source_flag_index:
fail("%s argument is not found in the compile command. %s" % (source_flag, str(args)))
if source_flag_index + 1 >= len(args):
fail("Source file to be compiled is missing from the command.")
# On Windows, filesystem paths should use '\', but GN creates build commands
# that use '/'.
# The original logic in clang_code_coverage_wrapper.py uses
# os.path.normpath() to ensure to ensure that the path uses the correct
# separator for the current platform. i.e. '\' on Windows and '/' otherwise
# Siso's ctx.fs.canonpath() ensures '/' on all platforms, instead.
# TODO: Consdier coverting the paths in instrument file and hardcoded lists
# only once at initialization if it improves performance.
compile_source_file = ctx.fs.canonpath(args[source_flag_index + 1])
extension = compile_source_file.rsplit(".", 1)[1]
if not extension in ["c", "cc", "cpp", "cxx", "m", "mm", "S"]:
fail("Invalid source file %s found. extension=%s" % (compile_source_file, extension))
exclusion_list = _COVERAGE_EXCLUSION_LIST_MAP.get(
target_os,
_DEFAULT_COVERAGE_EXCLUSION_LIST,
)
exclusion_list = [ctx.fs.canonpath(f) for f in exclusion_list]
force_list = _COVERAGE_FORCE_LIST_MAP.get(target_os, [])
force_list = [ctx.fs.canonpath(f) for f in force_list]
files_to_instrument = []
if instrument_file:
files_to_instrument = str(ctx.fs.read(ctx.fs.canonpath(instrument_file))).splitlines()
files_to_instrument = [ctx.fs.canonpath(f) for f in files_to_instrument]
should_remove_flags = False
if compile_source_file not in force_list:
if compile_source_file in exclusion_list:
should_remove_flags = True
elif instrument_file and compile_source_file not in files_to_instrument:
should_remove_flags = True
if should_remove_flags:
return _remove_flags_from_command(compile_command)
return compile_command
clang_code_coverage_wrapper = module(
"clang_code_coverage_wrapper",
run = __run,
)
# LINT.ThenChange(/build/toolchain/clang_code_coverage_wrapper.py)
