.bazelrc

common --enable_platform_specific_config
build --verbose_failures
build --build_tag_filters=-off-by-default
test --test_tag_filters=-off-by-default

# Not using bzlmod for dependencies yet
common --noenable_bzlmod

# TODO(soon): bazel7 enables Build without the Bytes (BwoB) by default. This could significantly
# speed up builds using the remote cache since less data needs to be fetched. Unfortunately, it
# appears to cause build failures due to https://github.com/bazelbuild/bazel/issues/20559 at this
# time. Use --remote_download_all to disable BwoB for now.
# When that issue and https://github.com/bazelbuild/bazel/issues/20576 have been addressed, we can
# also explore --remote_download_minimal.
build --remote_download_all

# Enable webgpu
build --//src/workerd/io:enable_experimental_webgpu=True

# Dawn tint build flags
build --@dawn//src/tint:tint_build_glsl_writer=False
build --@dawn//src/tint:tint_build_glsl_validator=False
build --@dawn//src/tint:tint_build_hlsl_writer=True
build --@dawn//src/tint:tint_build_ir=False
build --@dawn//src/tint:tint_build_msl_writer=True
build --@dawn//src/tint:tint_build_spv_reader=False
build --@dawn//src/tint:tint_build_spv_writer=True
build --@dawn//src/tint:tint_build_wgsl_reader=True
build --@dawn//src/tint:tint_build_wgsl_writer=True

# Our dependencies (ICU, zlib, etc.) produce a lot of these warnings, so we disable them. Depending
# on the clang version, zlib either produces warnings for -Wdeprecated-non-prototype or does not
# have that option, so disable -Wunknown-warning-option there too.
build --per_file_copt='external/com_googlesource_chromium_icu@-Wno-ambiguous-reversed-operator,-Wno-deprecated-declarations'
build --host_per_file_copt='external/com_googlesource_chromium_icu@-Wno-ambiguous-reversed-operator,-Wno-deprecated-declarations'
build --per_file_copt='external/dawn@-Wno-shorten-64-to-32,-Wno-unneeded-internal-declaration'
build --host_per_file_copt='external/dawn@-Wno-shorten-64-to-32,-Wno-unneeded-internal-declaration'
build --per_file_copt='external/zlib@-Wno-unknown-warning-option,-Wno-deprecated-non-prototype'
build --host_per_file_copt='external/zlib@-Wno-unknown-warning-option,-Wnodeprecated-non-prototype'

# Enable C++20 to support std::unordered_map::contains(). Not sure why this is needed here, V8
# is supposed to work with C++14.
build:unix --per_file_copt='external/v8/src/compiler/graph-visualizer.cc@-std=c++20'
build:windows --per_file_copt='external/v8/src/compiler/graph-visualizer.cc@/std:c++20'

# Need to redefine _WIN32_WINNT to build dawn on Windows
build:windows --per_file_copt='external/dawn@-Wno-macro-redefined'
build:windows --host_per_file_copt='external/dawn@-Wno-macro-redefined'

# typescript configuration
# do more correct type checking
common --@aspect_rules_ts//ts:skipLibCheck=honor_tsconfig
# Use "tsc" as the transpiler when ts_project has no `transpiler` set.
common --@aspect_rules_ts//ts:default_to_tsc_transpiler

# optimized LTO build. you'll need a fairly recent clang for this to work
build:thin-lto -c opt
build:thin-lto --cxxopt='-flto=thin'
build:thin-lto --linkopt='-flto=thin'

# configuration used for performance profiling
build:profile --config=thin-lto
build:profile --copt="-fno-omit-frame-pointer" --copt="-mno-omit-leaf-frame-pointer"
build:profile --copt='-g1' --linkopt='-g1' --strip=never

# configuration used for performance benchmarking is the same as profiling for consistency
build:benchmark --config=profile

# Define a debug config which is primarily intended for local development.
build:debug -c dbg

# Using simple template names saves around 5% of binary size of workerd.
build:unix --cxxopt='-gsimple-template-names' --host_cxxopt='-gsimple-template-names'

# Define a config mode which is fastbuild but with basic debug info.
build:fastdbg -c fastbuild
build:fastdbg --cxxopt='-g1' --host_cxxopt='-g1'
build:fastdbg --linkopt='-g1' --host_linkopt='-g1'
build:fastdbg --strip=never
build:fastdbg --//:dead_strip=False

# Miscellaneous platform-independent options
build --@capnp-cpp//src/kj:openssl=True --@capnp-cpp//src/kj:zlib=True --@capnp-cpp//src/kj:brotli=True
build --cxxopt="-fbracket-depth=512" --host_cxxopt="-fbracket-depth=512"

# Additional Rust flags (see https://doc.rust-lang.org/rustc/codegen-options/index.html)
# Need to disable debug-assertions for fastbuild, should be off automatically for opt. As long as
# rust-level LTO is not enabled, LLVM bitcode is not needed so -C embed-bitcode=n provides a free
# improvement to build speed and rust-deps code size.
build --@rules_rust//:extra_rustc_flags=-C,panic=abort,-C,debug-assertions=n,-C,embed-bitcode=n
build --@rules_rust//:extra_exec_rustc_flags=-C,panic=abort,-C,debug-assertions=n,-C,embed-bitcode=n

build:fastdbg --@rules_rust//:extra_rustc_flags=-C,panic=unwind,-C,debug-assertions=y,-C,debuginfo=1,-C,embed-bitcode=n
build:fastdbg --@rules_rust//:extra_exec_rustc_flags=-C,panic=unwind,-C,debug-assertions=y,-C,debuginfo=1,-C,embed-bitcode=n

# TODO(later): -C codegen-units=1 improves code size and quality, should be enabled in a future
# release configuration even if lto is off. Similarly, adding -C lto=thin would improve binary size
# significantly – disable it for now due to compile errors and wrong code generation when bazel and
# rust use different LLVM versions.
build:thin-lto --@rules_rust//:extra_rustc_flags=-C,panic=abort,-C,codegen-units=1,-C,embed-bitcode=n

# common sanitizers options
build:sanitizer-common --@workerd//src/workerd/server:use_tcmalloc=False
build:sanitizer-common --copt="-fsanitize-link-c++-runtime" --linkopt="-fsanitize-link-c++-runtime"
build:sanitizer-common --copt="-Og"
build:sanitizer-common --copt="-g" --strip=never
build:sanitizer-common --copt="-fno-optimize-sibling-calls"
build:sanitizer-common --copt="-fno-omit-frame-pointer" --copt="-mno-omit-leaf-frame-pointer"

# address sanitizer (https://github.com/google/sanitizers/wiki/AddressSanitizer)
build:asan --config=sanitizer-common
build:asan --copt="-fsanitize=address" --linkopt="-fsanitize=address"
build:asan --test_env=ASAN_OPTIONS=abort_on_error=true

#
# Linux and macOS
#
build:unix --workspace_status_command=./tools/unix/workspace-status.sh

build:unix --cxxopt='-std=c++20' --host_cxxopt='-std=c++20'
build:unix --@capnp-cpp//src/kj:libdl=True

build:unix --action_env=BAZEL_COMPILER=clang
build:unix --action_env=CC=clang
build:unix --action_env=CXX=clang++

build:unix --test_env=LLVM_SYMBOLIZER=llvm-symbolizer

# Warning options.
build:unix --cxxopt='-Wall' --host_cxxopt='-Wall'
build:unix --cxxopt='-Wextra' --host_cxxopt='-Wextra'
build:unix --cxxopt='-Wunused-function' --host_cxxopt='-Wunused-function'
build:unix --cxxopt='-Wunused-lambda-capture' --host_cxxopt='-Wunused-lambda-capture'
build:unix --cxxopt='-Wunused-variable' --host_cxxopt='-Wunused-variable'
build:unix --cxxopt='-Wno-strict-aliasing' --host_cxxopt='-Wno-strict-aliasing'
build:unix --cxxopt='-Wno-sign-compare' --host_cxxopt='-Wno-sign-compare'
build:unix --cxxopt='-Wno-unused-parameter' --host_cxxopt='-Wno-unused-parameter'
build:unix --cxxopt='-Wno-missing-field-initializers' --host_cxxopt='-Wno-missing-field-initializers'
build:unix --cxxopt='-Wno-ignored-qualifiers' --host_cxxopt='-Wno-ignored-qualifiers'

build:linux --config=unix
build:macos --config=unix

# Support macOS 11 as the minimum version. There should be at least a warning when backward
# compatibility is broken as -Wunguarded-availability-new is enabled by default.
# TODO (cleanup): macOS 11.X is now EOL, bump this to macOS 12.5 soon.
build:macos --macos_minimum_os=11.5 --host_macos_minimum_os=11.5

# Avoid emitting duplicate unwind info where compact unwind info can be used. This reduces the
# object size by ~5% on average, improving disk space usage and link times. The final binary size
# is not affected. Note that this is on-by-default on arm64, but turning it on for all mac builds
# is easier than adding the flag only on x86. See https://reviews.llvm.org/D122258 for detailed
# information on the flag.
build:macos --copt='-femit-dwarf-unwind=no-compact-unwind'

# On Linux, always link libc++ statically to avoid compatibility issues with different OS versions.
# macOS links with dynamic libc++ by default, which has good backwards compatibility.
build:linux --cxxopt='-stdlib=libc++' --host_cxxopt='-stdlib=libc++'
build:linux --linkopt='-stdlib=libc++' --host_linkopt='-stdlib=libc++'
build:linux --action_env=BAZEL_LINKLIBS='-l%:libc++.a -lm -static-libgcc'

# On Linux, enable PIC. In macos pic is the default, and the objc_library rule does not work
# correctly if we use this flag since it will not find the object files to include
# https://github.com/bazelbuild/bazel/issues/12439#issuecomment-914449079
build:linux --force_pic

# On Linux, garbage collection sections and optimize binary size. These do not apply to the macOS
# toolchain.
build:linux --linkopt="-Wl,--gc-sections" --linkopt="-Wl,-O2"
build:linux --cxxopt="-ffunction-sections" --host_cxxopt="-ffunction-sections"
build:linux --cxxopt="-fdata-sections" --host_cxxopt="-fdata-sections"

# TODO(later): rustc's -C,codegen-units=1 and ld/lld's -Wl,-O2 on Linux/possibly Windows should
# bring an additional binary size improvement. These should only be enabled in opt mode which won't
# be possible in bazelrc without establishing a release configuration, but it can be done using the
# extra_rustc_flags parameter in rust_register_toolchains() and by modifying linkopts in kj_test()
# and wd_cc_binary() similar to how the use_dead_strip flag is used. The binary size improvement is
# modest (~ 300kb), but if we encounter size concerns again this would be a good place to start.

#
# Windows
#

# See https://bazel.build/configure/windows#symlink
startup --windows_enable_symlinks
build:windows --workspace_status_command=./tools/windows/workspace-status.cmd
build:windows --enable_runfiles
# We use LLVM's MSVC-compatible compiler driver to compile our code on Windows,
# as opposed to using MSVC directly. This enables us to use the "same" compiler
# frontend on Linux, macOS, and Windows, massively reducing the effort required
# to compile workerd on Windows. Notably, this provides proper support for
# `#pragma once` when using symlinked virtual includes, `__atomic_*` functions,
# a standards-compliant preprocessor, support for GNU statement expressions
# used by some KJ macros, and understands the `.c++` extension by default.
# As of bazel 7, incompatible_enable_cc_toolchain_resolution is enabled by default, so we need to
# define a platform for the clang-cl build.
build:windows --extra_toolchains=@local_config_cc//:cc-toolchain-x64_windows-clang-cl
build:windows --extra_execution_platforms=//:x64_windows-clang-cl

# The Windows fastbuild bazel configuration is broken in that it necessarily generates PDB debug
# information while the Linux and macOS toolchains only compile with debug information in the dbg
# configuration or when requested with the -g flag. This causes huge increases in compile time and
# disk/cache space usage – a single test may come with a 490MB PDB file.
# In an optional configuration, use the opt configuration and manually disable optimizations as a
# workaround.

build:windows_no_dbg -c opt
build:windows_no_dbg --copt='-O0' --host_copt='-O0'
build:windows_no_dbg --copt='/Od' --host_copt='/Od'
build:windows_no_dbg --copt='/INCREMENTAL:NO' --host_copt='/INCREMENTAL:NO'
build:windows_no_dbg --features=-smaller_binary --features=-disable_assertions_feature

# Mitigate the large size impact of Windows debug binaries somewhat by applying string merging and
# linker garbage collection.
build:windows_dbg --config=debug
build:windows_dbg --copt='/Gy' --copt='/Gw' --copt='/GF'
build:windows_dbg --linkopt='/OPT:REF'

build:windows --cxxopt='/std:c++20' --host_cxxopt='/std:c++20'
build:windows --cxxopt='/await' --host_cxxopt='/await'
build:windows --copt='/D_CRT_USE_BUILTIN_OFFSETOF' --host_copt='/D_CRT_USE_BUILTIN_OFFSETOF'
build:windows --copt='/DWINDOWS_LEAN_AND_MEAN' --host_copt='/DWINDOWS_LEAN_AND_MEAN'
# The `/std:c++20` argument is unused during boringssl compilation and we don't
# want a warning when compiling each file.
build:windows --copt='-Wno-unused-command-line-argument' --host_copt='-Wno-unused-command-line-argument'

# MSVC disappointingly sets __cplusplus to 199711L by default. Defining /Zc:__cplusplus makes it
# set the correct value. We currently don't check __cplusplus, but some dependencies do.
build:windows --cxxopt='/Zc:__cplusplus' --host_cxxopt='/Zc:__cplusplus'

# enable clang coverage: https://clang.llvm.org/docs/SourceBasedCodeCoverage.html
build:clang-coverage --copt="-fprofile-instr-generate" --linkopt="-fprofile-instr-generate"
build:clang-coverage --copt="-fcoverage-mapping" --linkopt="-fcoverage-mapping"