utils/bazel/.bazelrc - llvm-project - Git at Google

 # This file is licensed under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

 ###############################################################################
 # Common flags that apply to all configurations.
 # Use sparingly for things common to all compilers and platforms.
 ###############################################################################
 # Prevent invalid caching if input files are modified during a build.
 build --experimental_guard_against_concurrent_changes

 # Automatically enable --config=(linux|macos|windows) based on the host
 build --enable_platform_specific_config

 # In opt mode, bazel by default builds both PIC and non-PIC object files for
 # tests vs binaries. We don't need this feature and it slows down opt builds
 # considerably.
 # TODO: Remove platform specifics we're on bazel 7.x https://github.com/bazelbuild/bazel/issues/12439
 # Apple platforms always enable pic so this flag is unnecessary anyways
 build:linux --force_pic
 build:windows --force_pic

 # Shared objects take up more space. With fast linkers and binaries that aren't
 # super large, the benefits of shared objects are minimal.
 build --dynamic_mode=off

 # Rely on compiler flags to compile with debug info/strip rather than stripping
 # based on compilation_mode.
 build --strip=never

 # Add layering check to all projects.
 build --features=layering_check

 # Opt out of legacy lax behavior implicitly exporting files that are rule inputs
 # with default visibility.
 # See: https://bazel.build/reference/be/functions#exports_files
 build --incompatible_no_implicit_file_export

 # Enable so downstream users can flip this flag globally, this should
 # eventually become the default
 common --incompatible_disallow_empty_glob

 # TODO: Remove once we move to bazel 7.x
 build --experimental_cc_shared_library

 ###############################################################################
 # Options to select different strategies for linking potential dependent
 # libraries. The default leaves it disabled.
 ###############################################################################

 build:zlib_external --repo_env=BAZEL_LLVM_ZLIB_STRATEGY=external
 build:zlib_system --repo_env=BAZEL_LLVM_ZLIB_STRATEGY=system

 build:terminfo_external --repo_env=BAZEL_LLVM_TERMINFO_STRATEGY=external
 build:terminfo_system --repo_env=BAZEL_LLVM_TERMINFO_STRATEGY=system

 ###############################################################################
 # Options for "generic_clang" builds: these options should generally apply to
 # builds using a Clang-based compiler, and default to the `clang` executable on
 # the `PATH`. While these are provided for convenience and may serve as a
 # reference, it would be preferable for users to configure an explicit C++
 # toolchain instead of relying on `.bazelrc` files.
 ###############################################################################

 # Set the default compiler to the `clang` binary on the `PATH`.
 build:generic_clang --repo_env=CC=clang

 # C++17 standard version is required.
 build:generic_clang --cxxopt=-std=c++17 --host_cxxopt=-std=c++17

 # Use `-Wall` for Clang.
 build:generic_clang --copt=-Wall --host_copt=-Wall

 # The Clang available on MacOS has a warning that isn't clean on MLIR code. The
 # warning doesn't show up with more recent Clangs, so just disable for now.
 build:generic_clang --cxxopt=-Wno-range-loop-analysis --host_cxxopt=-Wno-range-loop-analysis

 # Build errors are not a helpful way to enforce deprecation in-repo and it is
 # not the point of the Bazel build to catch usage of deprecated APIs.
 build:generic_clang --copt=-Wno-deprecated --host_copt=-Wno-deprecated

 # lld links faster than other linkers. Assume that anybody using clang also has
 # lld available.
 build:generic_clang --linkopt=-fuse-ld=lld --host_linkopt=-fuse-ld=lld

 ###############################################################################
 # Options for "generic_gcc" builds: these options should generally apply to
 # builds using a GCC-based compiler, and default to the `gcc` executable on
 # the `PATH`. While these are provided for convenience and may serve as a
 # reference, it would be preferable for users to configure an explicit C++
 # toolchain instead of relying on `.bazelrc` files.
 ###############################################################################

 # Set the default compiler to the `gcc` binary on the `PATH`.
 build:generic_gcc --repo_env=CC=gcc

 # C++17 standard version is required.
 build:generic_gcc --cxxopt=-std=c++17 --host_cxxopt=-std=c++17

 # Build errors are not a helpful way to enforce deprecation in-repo and it is
 # not the point of the Bazel build to catch usage of deprecated APIs.
 build:generic_gcc --copt=-Wno-deprecated --host_copt=-Wno-deprecated

 # Disable GCC warnings that are noisy and/or false positives on LLVM code.
 # These need to be global as some code triggering these is in header files.
 build:generic_gcc --copt=-Wno-unused-parameter --host_copt=-Wno-unused-parameter
 build:generic_gcc --copt=-Wno-comment --host_copt=-Wno-comment
 build:generic_gcc --cxxopt=-Wno-class-memaccess --host_cxxopt=-Wno-class-memaccess
 build:generic_gcc --copt=-Wno-maybe-uninitialized --host_copt=-Wno-maybe-uninitialized
 build:generic_gcc --copt=-Wno-misleading-indentation --host_copt=-Wno-misleading-indentation

 ###############################################################################
 # Generic Windows flags common to both MSVC and Clang.
 ###############################################################################

 # C++17 standard version is required.
 build:windows --cxxopt=/std:c++17 --host_cxxopt=/std:c++17

 # Other generic dialect flags.
 build:windows --copt=/Zc:strictStrings --host_copt=/Zc:strictStrings
 build:windows --copt=/Oi --host_copt=/Oi
 build:windows --cxxopt=/Zc:rvalueCast --host_cxxopt=/Zc:rvalueCast

 # Use the more flexible bigobj format for C++ files that have lots of symbols.
 build:windows --cxxopt=/bigobj --host_cxxopt=/bigobj

 ###############################################################################
 # Windows specific flags for building with MSVC.
 ###############################################################################

 build:msvc --config=windows

 build:msvc --copt=/WX --host_copt=/WX    # Treat warnings as errors...
 # ...but disable the ones that are violated
 build:msvc --copt=/wd4141 --host_copt=/wd4141 # inline used more than once
 build:msvc --copt=/wd4244 --host_copt=/wd4244 # conversion type -> type
 build:msvc --copt=/wd4267 --host_copt=/wd4267 # conversion size_t -> type
 build:msvc --copt=/wd4273 --host_copt=/wd4273 # multiple definitions with different dllimport
 build:msvc --copt=/wd4319 --host_copt=/wd4319 # zero-extending after complement
 build:msvc --copt=/wd4624 --host_copt=/wd4624 # destructor was implicitly defined as deleted
 build:msvc --copt=/wd4804 --host_copt=/wd4804 # comparisons between bool and int
 build:msvc --copt=/wd4805 --host_copt=/wd4805 # comparisons between bool and int

 build:msvc --linkopt=/WX --host_linkopt=/WX # Treat warnings as errors...
 # ...but disable the ones that are violated.
 build:msvc --linkopt=/IGNORE:4001 --host_linkopt=/IGNORE:4001 # no object files

 ###############################################################################
 # Options for Windows `clang-cl` builds.
 ###############################################################################

 # We just start with the baseline Windows config as `clang-cl` doesn't accept
 # some of the generic Clang flags.
 build:clang-cl --config=windows

 # Switch from MSVC to the `clang-cl` compiler.
 build:clang-cl --compiler=clang-cl

 # Use Clang's internal warning flags instead of the ones that sometimes map
 # through to MSVC's flags.
 build:clang-cl --copt=/clang:-Wall --host_copt=/clang:-Wall
 build:clang-cl --copt=/clang:-Werror --host_copt=/clang:-Werror

 # This doesn't appear to be enforced by any upstream bot.
 build:clang-cl --copt=/clang:-Wno-unused --host_copt=/clang:-Wno-unused

 # There appears to be an unused constant in GoogleTest on Windows.
 build:clang-cl --copt=/clang:-Wno-unused-const-variable --host_copt=/clang:-Wno-unused-const-variable

 # Disable some warnings hit even with `clang-cl` in Clang's own code.
 build:clang-cl --copt=/clang:-Wno-inconsistent-dllimport --host_copt=/clang:-Wno-inconsistent-dllimport
 build:clang-cl --cxxopt=/clang:-Wno-c++11-narrowing --host_cxxopt=/clang:-Wno-c++11-narrowing

 ###############################################################################
 # Options for continuous integration.
 ###############################################################################

 # -O1 tries to provide a reasonable tradeoff between compile times and runtime
 # performance. However, if we start running more tests (e.g. all of
 # check-clang) we may want more optimizations.
 # Note for anybody considering using --compilation_mode=opt in CI, it builds
 # most files twice, one PIC version for shared libraries in tests, and one
 # non-PIC version for binaries.
 build:ci --copt=-O1

 # Use clang.
 build:ci --config=generic_clang

 # Speedup bazel using a ramdisk.
 build:ci --sandbox_base=/dev/shm

 # Use system's mpfr and pfm instead of building it from source.
 # This is non hermetic but helps with compile time.
 build:ci --@llvm-project//libc:mpfr=system
 build:ci --@llvm-project//llvm:pfm=system

 # Don't build/test targets tagged with "nobuildkite".
 build:ci --build_tag_filters=-nobuildkite
 build:ci --test_tag_filters=-nobuildkite

 # Show as many errors as possible.
 build:ci --keep_going

 # Show test errors.
 build:ci --test_output=errors

 ###############################################################################

 # The user.bazelrc file is not checked in but available for local mods.
 # Always keep this at the end of the file so that user flags override.
 try-import %workspace%/user.bazelrc
	# This file is licensed under the Apache License v2.0 with LLVM Exceptions.
	# See https://llvm.org/LICENSE.txt for license information.
	# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

	###############################################################################
	# Common flags that apply to all configurations.
	# Use sparingly for things common to all compilers and platforms.
	###############################################################################
	# Prevent invalid caching if input files are modified during a build.
	build --experimental_guard_against_concurrent_changes

	# Automatically enable --config=(linux\|macos\|windows) based on the host
	build --enable_platform_specific_config

	# In opt mode, bazel by default builds both PIC and non-PIC object files for
	# tests vs binaries. We don't need this feature and it slows down opt builds
	# considerably.
	# TODO: Remove platform specifics we're on bazel 7.x https://github.com/bazelbuild/bazel/issues/12439
	# Apple platforms always enable pic so this flag is unnecessary anyways
	build:linux --force_pic
	build:windows --force_pic

	# Shared objects take up more space. With fast linkers and binaries that aren't
	# super large, the benefits of shared objects are minimal.
	build --dynamic_mode=off

	# Rely on compiler flags to compile with debug info/strip rather than stripping
	# based on compilation_mode.
	build --strip=never

	# Add layering check to all projects.
	build --features=layering_check

	# Opt out of legacy lax behavior implicitly exporting files that are rule inputs
	# with default visibility.
	# See: https://bazel.build/reference/be/functions#exports_files
	build --incompatible_no_implicit_file_export

	# Enable so downstream users can flip this flag globally, this should
	# eventually become the default
	common --incompatible_disallow_empty_glob

	# TODO: Remove once we move to bazel 7.x
	build --experimental_cc_shared_library

	###############################################################################
	# Options to select different strategies for linking potential dependent
	# libraries. The default leaves it disabled.
	###############################################################################

	build:zlib_external --repo_env=BAZEL_LLVM_ZLIB_STRATEGY=external
	build:zlib_system --repo_env=BAZEL_LLVM_ZLIB_STRATEGY=system

	build:terminfo_external --repo_env=BAZEL_LLVM_TERMINFO_STRATEGY=external
	build:terminfo_system --repo_env=BAZEL_LLVM_TERMINFO_STRATEGY=system

	###############################################################################
	# Options for "generic_clang" builds: these options should generally apply to
	# builds using a Clang-based compiler, and default to the `clang` executable on
	# the `PATH`. While these are provided for convenience and may serve as a
	# reference, it would be preferable for users to configure an explicit C++
	# toolchain instead of relying on `.bazelrc` files.
	###############################################################################

	# Set the default compiler to the `clang` binary on the `PATH`.
	build:generic_clang --repo_env=CC=clang

	# C++17 standard version is required.
	build:generic_clang --cxxopt=-std=c++17 --host_cxxopt=-std=c++17

	# Use `-Wall` for Clang.
	build:generic_clang --copt=-Wall --host_copt=-Wall

	# The Clang available on MacOS has a warning that isn't clean on MLIR code. The
	# warning doesn't show up with more recent Clangs, so just disable for now.
	build:generic_clang --cxxopt=-Wno-range-loop-analysis --host_cxxopt=-Wno-range-loop-analysis

	# Build errors are not a helpful way to enforce deprecation in-repo and it is
	# not the point of the Bazel build to catch usage of deprecated APIs.
	build:generic_clang --copt=-Wno-deprecated --host_copt=-Wno-deprecated

	# lld links faster than other linkers. Assume that anybody using clang also has
	# lld available.
	build:generic_clang --linkopt=-fuse-ld=lld --host_linkopt=-fuse-ld=lld

	###############################################################################
	# Options for "generic_gcc" builds: these options should generally apply to
	# builds using a GCC-based compiler, and default to the `gcc` executable on
	# the `PATH`. While these are provided for convenience and may serve as a
	# reference, it would be preferable for users to configure an explicit C++
	# toolchain instead of relying on `.bazelrc` files.
	###############################################################################

	# Set the default compiler to the `gcc` binary on the `PATH`.
	build:generic_gcc --repo_env=CC=gcc

	# C++17 standard version is required.
	build:generic_gcc --cxxopt=-std=c++17 --host_cxxopt=-std=c++17

	# Build errors are not a helpful way to enforce deprecation in-repo and it is
	# not the point of the Bazel build to catch usage of deprecated APIs.
	build:generic_gcc --copt=-Wno-deprecated --host_copt=-Wno-deprecated

	# Disable GCC warnings that are noisy and/or false positives on LLVM code.
	# These need to be global as some code triggering these is in header files.
	build:generic_gcc --copt=-Wno-unused-parameter --host_copt=-Wno-unused-parameter
	build:generic_gcc --copt=-Wno-comment --host_copt=-Wno-comment
	build:generic_gcc --cxxopt=-Wno-class-memaccess --host_cxxopt=-Wno-class-memaccess
	build:generic_gcc --copt=-Wno-maybe-uninitialized --host_copt=-Wno-maybe-uninitialized
	build:generic_gcc --copt=-Wno-misleading-indentation --host_copt=-Wno-misleading-indentation

	###############################################################################
	# Generic Windows flags common to both MSVC and Clang.
	###############################################################################

	# C++17 standard version is required.
	build:windows --cxxopt=/std:c++17 --host_cxxopt=/std:c++17

	# Other generic dialect flags.
	build:windows --copt=/Zc:strictStrings --host_copt=/Zc:strictStrings
	build:windows --copt=/Oi --host_copt=/Oi
	build:windows --cxxopt=/Zc:rvalueCast --host_cxxopt=/Zc:rvalueCast

	# Use the more flexible bigobj format for C++ files that have lots of symbols.
	build:windows --cxxopt=/bigobj --host_cxxopt=/bigobj

	###############################################################################
	# Windows specific flags for building with MSVC.
	###############################################################################

	build:msvc --config=windows

	build:msvc --copt=/WX --host_copt=/WX # Treat warnings as errors...
	# ...but disable the ones that are violated
	build:msvc --copt=/wd4141 --host_copt=/wd4141 # inline used more than once
	build:msvc --copt=/wd4244 --host_copt=/wd4244 # conversion type -> type
	build:msvc --copt=/wd4267 --host_copt=/wd4267 # conversion size_t -> type
	build:msvc --copt=/wd4273 --host_copt=/wd4273 # multiple definitions with different dllimport
	build:msvc --copt=/wd4319 --host_copt=/wd4319 # zero-extending after complement
	build:msvc --copt=/wd4624 --host_copt=/wd4624 # destructor was implicitly defined as deleted
	build:msvc --copt=/wd4804 --host_copt=/wd4804 # comparisons between bool and int
	build:msvc --copt=/wd4805 --host_copt=/wd4805 # comparisons between bool and int

	build:msvc --linkopt=/WX --host_linkopt=/WX # Treat warnings as errors...
	# ...but disable the ones that are violated.
	build:msvc --linkopt=/IGNORE:4001 --host_linkopt=/IGNORE:4001 # no object files

	###############################################################################
	# Options for Windows `clang-cl` builds.
	###############################################################################

	# We just start with the baseline Windows config as `clang-cl` doesn't accept
	# some of the generic Clang flags.
	build:clang-cl --config=windows

	# Switch from MSVC to the `clang-cl` compiler.
	build:clang-cl --compiler=clang-cl

	# Use Clang's internal warning flags instead of the ones that sometimes map
	# through to MSVC's flags.
	build:clang-cl --copt=/clang:-Wall --host_copt=/clang:-Wall
	build:clang-cl --copt=/clang:-Werror --host_copt=/clang:-Werror

	# This doesn't appear to be enforced by any upstream bot.
	build:clang-cl --copt=/clang:-Wno-unused --host_copt=/clang:-Wno-unused

	# There appears to be an unused constant in GoogleTest on Windows.
	build:clang-cl --copt=/clang:-Wno-unused-const-variable --host_copt=/clang:-Wno-unused-const-variable

	# Disable some warnings hit even with `clang-cl` in Clang's own code.
	build:clang-cl --copt=/clang:-Wno-inconsistent-dllimport --host_copt=/clang:-Wno-inconsistent-dllimport
	build:clang-cl --cxxopt=/clang:-Wno-c++11-narrowing --host_cxxopt=/clang:-Wno-c++11-narrowing

	###############################################################################
	# Options for continuous integration.
	###############################################################################

	# -O1 tries to provide a reasonable tradeoff between compile times and runtime
	# performance. However, if we start running more tests (e.g. all of
	# check-clang) we may want more optimizations.
	# Note for anybody considering using --compilation_mode=opt in CI, it builds
	# most files twice, one PIC version for shared libraries in tests, and one
	# non-PIC version for binaries.
	build:ci --copt=-O1

	# Use clang.
	build:ci --config=generic_clang

	# Speedup bazel using a ramdisk.
	build:ci --sandbox_base=/dev/shm

	# Use system's mpfr and pfm instead of building it from source.
	# This is non hermetic but helps with compile time.
	build:ci --@llvm-project//libc:mpfr=system
	build:ci --@llvm-project//llvm:pfm=system

	# Don't build/test targets tagged with "nobuildkite".
	build:ci --build_tag_filters=-nobuildkite
	build:ci --test_tag_filters=-nobuildkite

	# Show as many errors as possible.
	build:ci --keep_going

	# Show test errors.
	build:ci --test_output=errors

	###############################################################################

	# The user.bazelrc file is not checked in but available for local mods.
	# Always keep this at the end of the file so that user flags override.
	try-import %workspace%/user.bazelrc