| # Copyright (c) 2013 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. |
| |
| # ============================================================================= |
| # PLATFORM SELECTION |
| # ============================================================================= |
| # |
| # There are two main things to set: "os" and "cpu". The "toolchain" is the name |
| # of the GN thing that encodes combinations of these things. |
| # |
| # Users typically only set the variables "target_os" and "target_cpu" in "gn |
| # args", the rest are set up by our build and internal to GN. |
| # |
| # There are three different types of each of these things: The "host" |
| # represents the computer doing the compile and never changes. The "target" |
| # represents the main thing we're trying to build. The "current" represents |
| # which configuration is currently being defined, which can be either the |
| # host, the target, or something completely different (like nacl). GN will |
| # run the same build file multiple times for the different required |
| # configuration in the same build. |
| # |
| # This gives the following variables: |
| # - host_os, host_cpu, host_toolchain |
| # - target_os, target_cpu, default_toolchain |
| # - current_os, current_cpu, current_toolchain. |
| # |
| # Note the default_toolchain isn't symmetrical (you would expect |
| # target_toolchain). This is because the "default" toolchain is a GN built-in |
| # concept, and "target" is something our build sets up that's symmetrical with |
| # its GYP counterpart. Potentially the built-in default_toolchain variable |
| # could be renamed in the future. |
| # |
| # When writing build files, to do something only for the host: |
| # if (current_toolchain == host_toolchain) { ... |
| |
| if (target_os == "") { |
| target_os = host_os |
| } |
| |
| assert(host_cpu != "") |
| assert(target_cpu != "") |
| |
| if (current_cpu == "") { |
| current_cpu = target_cpu |
| } |
| if (current_os == "") { |
| current_os = target_os |
| } |
| |
| # ============================================================================= |
| # BUILD FLAGS |
| # ============================================================================= |
| # |
| # This block lists input arguments to the build, along with their default |
| # values. |
| # |
| # If a value is specified on the command line, it will overwrite the defaults |
| # given in a declare_args block, otherwise the default will be used. |
| # |
| # YOU SHOULD ALMOST NEVER NEED TO ADD FLAGS TO THIS FILE. GN allows any file in |
| # the build to declare build flags. If you need a flag for a single component, |
| # you can just declare it in the corresponding BUILD.gn file. If you need a |
| # flag in multiple components, there are a few options: |
| # |
| # - If your feature is a single target, say //components/foo, and the targets |
| # depending on foo need to have some define set if foo is enabled: (1) Write |
| # a declare_args block in foo's BUILD.gn file listing your enable_foo build |
| # flag. (2) Write a config in that file listing the define, and list that |
| # config in foo's public_configs. This will propagate that define to all the |
| # targets depending on foo. (3) When foo is not enabled, just make it expand |
| # to an empty group (or whatever's appropriate for the "off" state of your |
| # feature. |
| # |
| # - If a semi-random set of targets need to know about a define: (1) In the |
| # lowest level of the build that knows about this feature, add a declare_args |
| # block in the build file for your enable flag. (2) Write a config that adds |
| # a define conditionally based on that build flags. (3) Manually add that |
| # config to the "configs" applying to the targets that need the define. |
| # |
| # - If a semi-random set of targets need to know about the build flag (to do |
| # file inclusion or exclusion, more than just defines): (1) Write a .gni file |
| # in the lowest-level directory that knows about the feature. (2) Put the |
| # declare_args block with your build flag in that .gni file. (3) Import that |
| # .gni file from the BUILD.gn files that need the flag. |
| # |
| # Other advice: |
| # |
| # - Use boolean values when possible. If you need a default value that expands |
| # to some complex thing in the default case (like the location of the |
| # compiler which would be computed by a script), use a default value of -1 or |
| # the empty string. Outside of the declare_args block, conditionally expand |
| # the default value as necessary. |
| # |
| # - Use a name like "use_foo" or "is_foo" (whatever is more appropriate for |
| # your feature) rather than just "foo". |
| # |
| # - Write good comments directly above the declaration with no blank line. |
| # These comments will appear as documentation in "gn args --list". |
| # |
| # - Don't call exec_script inside declare_args. This will execute the script |
| # even if the value is overridden, which is wasteful. See first bullet. |
| |
| # There is no component build for the Dart VM, but build files in some |
| # dependencies check this. |
| is_component_build = false |
| |
| declare_args() { |
| # Debug build. |
| is_debug = true |
| |
| # Release build. |
| is_release = false |
| |
| # Product build. |
| is_product = false |
| |
| # Set to true when compiling with the Clang compiler. Typically this is used |
| # to configure warnings. |
| is_clang = current_os == "mac" || current_os == "linux" |
| |
| # Compile for Address Sanitizer to find memory bugs. |
| is_asan = false |
| |
| # Compile for Leak Sanitizer to find leaks. |
| is_lsan = false |
| |
| # Compile for Memory Sanitizer to find uninitialized reads. |
| is_msan = false |
| |
| # Compile for Thread Sanitizer to find threading bugs. |
| is_tsan = false |
| |
| # Compile for Undefined Behavior Sanitizer to find reliance on undefined behavior. |
| is_ubsan = false |
| |
| # Compile for execution in user-mode QEMU. |
| is_qemu = false |
| } |
| |
| # ============================================================================= |
| # OS DEFINITIONS |
| # ============================================================================= |
| # |
| # We set these various is_FOO booleans for convenience in writing OS-based |
| # conditions. |
| # |
| # - is_android, is_chromeos, is_ios, and is_win should be obvious. |
| # - is_mac is set only for desktop Mac. It is not set on iOS. |
| # - is_posix is true for mac and any Unix-like system (basically everything |
| # except Windows). |
| # - is_linux is true for desktop Linux and ChromeOS, but not Android (which is |
| # generally too different despite being based on the Linux kernel). |
| # |
| # Do not add more is_* variants here for random lesser-used Unix systems like |
| # aix or one of the BSDs. If you need to check these, just check the |
| # current_os value directly. |
| |
| if (current_os == "win") { |
| is_android = false |
| is_chromeos = false |
| is_fuchsia = false |
| is_ios = false |
| is_linux = false |
| is_mac = false |
| is_nacl = false |
| is_posix = false |
| is_win = true |
| } else if (current_os == "mac") { |
| is_android = false |
| is_chromeos = false |
| is_fuchsia = false |
| is_ios = false |
| is_linux = false |
| is_mac = true |
| is_nacl = false |
| is_posix = true |
| is_win = false |
| } else if (current_os == "android") { |
| is_android = true |
| is_chromeos = false |
| is_fuchsia = false |
| is_ios = false |
| is_linux = false |
| is_mac = false |
| is_nacl = false |
| is_posix = true |
| is_win = false |
| } else if (current_os == "linux") { |
| is_android = false |
| is_chromeos = false |
| is_fuchsia = false |
| is_ios = false |
| is_linux = true |
| is_mac = false |
| is_nacl = false |
| is_posix = true |
| is_win = false |
| } |
| |
| # ============================================================================= |
| # BUILD OPTIONS |
| # ============================================================================= |
| |
| # These Sanitizers all imply using the Clang compiler. On Windows they either |
| # don't work or work differently. |
| if (!is_clang && (is_asan || is_lsan || is_msan || is_tsan || is_ubsan)) { |
| is_clang = true |
| } |
| |
| # ============================================================================= |
| # TARGET DEFAULTS |
| # ============================================================================= |
| # |
| # Set up the default configuration for every build target of the given type. |
| # The values configured here will be automatically set on the scope of the |
| # corresponding target. Target definitions can add or remove to the settings |
| # here as needed. |
| |
| # Holds all configs used for making native executables and libraries, to avoid |
| # duplication in each target below. |
| _native_compiler_configs = [ |
| "//build/config/compiler:compiler", |
| "//build/config/compiler:clang_stackrealign", |
| "//build/config/compiler:compiler_arm_fpu", |
| "//build/config/compiler:compiler_arm_thumb", |
| "//build/config/compiler:chromium_code", |
| "//build/config/compiler:default_include_dirs", |
| "//build/config/compiler:no_rtti", |
| "//build/config/compiler:runtime_library", |
| ] |
| if (is_win) { |
| _native_compiler_configs += [ |
| "//build/config/win:lean_and_mean", |
| "//build/config/win:nominmax", |
| "//build/config/win:sdk", |
| "//build/config/win:unicode", |
| "//build/config/win:winver", |
| ] |
| } |
| if (is_posix) { |
| _native_compiler_configs += [ |
| "//build/config/gcc:no_exceptions", |
| "//build/config/gcc:relative_paths", |
| ] |
| if (is_product) { |
| _native_compiler_configs += |
| [ "//build/config/gcc:symbol_visibility_hidden" ] |
| } |
| } |
| |
| if (is_linux) { |
| _native_compiler_configs += [ "//build/config/linux:sdk" ] |
| } else if (is_mac) { |
| _native_compiler_configs += [ "//build/config/mac:sdk" ] |
| } else if (is_android) { |
| _native_compiler_configs += [ "//build/config/android:sdk" ] |
| } |
| |
| if (is_clang) { |
| _native_compiler_configs += [ "//build/config/clang:extra_warnings" ] |
| } |
| |
| # Optimizations and debug checking. |
| if (is_debug) { |
| _native_compiler_configs += [ "//build/config:debug" ] |
| _default_optimization_config = "//build/config/compiler:no_optimize" |
| } else if (is_release) { |
| _native_compiler_configs += [ "//build/config:release" ] |
| _default_optimization_config = "//build/config/compiler:optimize" |
| } else { |
| assert(is_product) |
| _native_compiler_configs += [ "//build/config:product" ] |
| _default_optimization_config = "//build/config/compiler:optimize" |
| } |
| _native_compiler_configs += [ _default_optimization_config ] |
| |
| # zlib's BUILD.gn expects to have this config among default configs. |
| _native_compiler_configs += [ "//build/config/compiler:default_optimization" ] |
| |
| # Symbol setup. |
| _default_symbols_config = "//build/config/compiler:symbols" |
| _native_compiler_configs += [ _default_symbols_config ] |
| |
| # Windows linker setup for EXEs and DLLs. |
| if (is_win) { |
| _windows_linker_configs = [ |
| "//build/config/win:default_incremental_linking", |
| "//build/config/win:sdk_link", |
| "//build/config/win:common_linker_setup", |
| |
| # Default to console-mode apps. Most of our targets are tests and such |
| # that shouldn't use the windows subsystem. |
| "//build/config/win:console", |
| ] |
| } |
| |
| # Executable defaults. |
| _executable_configs = _native_compiler_configs |
| if (is_win) { |
| _executable_configs += _windows_linker_configs |
| } else if (is_mac) { |
| _executable_configs += [ |
| "//build/config/mac:mac_dynamic_flags", |
| "//build/config/mac:mac_executable_flags", |
| ] |
| } else if (is_linux) { |
| _executable_configs += [ |
| "//build/config/gcc:executable_ldconfig", |
| "//build/config/linux:executable_config", |
| ] |
| } else if (is_android) { |
| _executable_configs += [ |
| "//build/config/gcc:executable_ldconfig", |
| "//build/config/android:executable_config", |
| ] |
| } |
| set_defaults("executable") { |
| configs = _executable_configs |
| } |
| |
| # Static library defaults. |
| set_defaults("static_library") { |
| configs = _native_compiler_configs |
| } |
| |
| # Shared library defaults (also for components in component mode). |
| _shared_library_configs = _native_compiler_configs |
| if (is_win) { |
| _shared_library_configs += _windows_linker_configs |
| } else if (is_mac) { |
| _shared_library_configs += [ "//build/config/mac:mac_dynamic_flags" ] |
| } |
| set_defaults("shared_library") { |
| configs = _shared_library_configs |
| } |
| |
| # Source set defaults (also for components in non-component mode). |
| set_defaults("source_set") { |
| configs = _native_compiler_configs |
| } |
| set_defaults("component") { |
| configs = _native_compiler_configs |
| } |
| |
| # ============================================================================== |
| # TOOLCHAIN SETUP |
| # ============================================================================== |
| # |
| # Here we set the default toolchain, as well as the variable host_toolchain |
| # which will identify the toolchain corresponding to the local system when |
| # doing cross-compiles. When not cross-compiling, this will be the same as the |
| # default toolchain. |
| |
| if (is_win) { |
| # On windows we use the same toolchain for host and target by default. |
| host_toolchain = "//build/toolchain/win:$current_cpu" |
| set_default_toolchain("$host_toolchain") |
| } else if (is_android) { |
| if (host_os == "linux") { |
| if (host_cpu == "x86" || host_cpu == "x64") { |
| host_toolchain = "//build/toolchain/linux:clang_$host_cpu" |
| } else { |
| host_toolchain = "//build/toolchain/linux:$host_cpu" |
| } |
| } else if (host_os == "mac") { |
| host_toolchain = "//build/toolchain/mac:clang_$host_cpu" |
| } else { |
| assert(false, "Unknown host for android cross compile") |
| } |
| if (is_clang) { |
| set_default_toolchain("//build/toolchain/android:clang_$current_cpu") |
| } else { |
| set_default_toolchain("//build/toolchain/android:$current_cpu") |
| } |
| } else if (is_linux) { |
| if (is_clang) { |
| host_toolchain = "//build/toolchain/linux:clang_$host_cpu" |
| set_default_toolchain("//build/toolchain/linux:clang_$current_cpu") |
| } else { |
| host_toolchain = "//build/toolchain/linux:$host_cpu" |
| set_default_toolchain("//build/toolchain/linux:$current_cpu") |
| } |
| } else if (is_mac) { |
| host_toolchain = "//build/toolchain/mac:clang_x64" |
| set_default_toolchain(host_toolchain) |
| } |
| |
| # ============================================================================== |
| # COMPONENT SETUP |
| # ============================================================================== |
| |
| # Don't try to do component builds for the standalone Dart VM. |
| assert(!is_component_build) |
| component_mode = "source_set" |
| |
| template("component") { |
| source_set(target_name) { |
| # See above. |
| configs = [] # Prevent list overwriting warning. |
| configs = invoker.configs |
| |
| # See above call. |
| set_sources_assignment_filter([]) |
| |
| if (defined(invoker.all_dependent_configs)) { |
| all_dependent_configs = invoker.all_dependent_configs |
| } |
| if (defined(invoker.allow_circular_includes_from)) { |
| allow_circular_includes_from = invoker.allow_circular_includes_from |
| } |
| if (defined(invoker.cflags)) { |
| cflags = invoker.cflags |
| } |
| if (defined(invoker.cflags_c)) { |
| cflags_c = invoker.cflags_c |
| } |
| if (defined(invoker.cflags_cc)) { |
| cflags_cc = invoker.cflags_cc |
| } |
| if (defined(invoker.cflags_objc)) { |
| cflags_objc = invoker.cflags_objc |
| } |
| if (defined(invoker.cflags_objcc)) { |
| cflags_objcc = invoker.cflags_objcc |
| } |
| if (defined(invoker.check_includes)) { |
| check_includes = invoker.check_includes |
| } |
| if (defined(invoker.data)) { |
| data = invoker.data |
| } |
| if (defined(invoker.data_deps)) { |
| data_deps = invoker.data_deps |
| } |
| if (defined(invoker.datadeps)) { |
| datadeps = invoker.datadeps |
| } |
| if (defined(invoker.defines)) { |
| defines = invoker.defines |
| } |
| if (defined(invoker.deps)) { |
| deps = invoker.deps |
| } |
| if (defined(invoker.direct_dependent_configs)) { |
| direct_dependent_configs = invoker.direct_dependent_configs |
| } |
| if (defined(invoker.forward_dependent_configs_from)) { |
| forward_dependent_configs_from = invoker.forward_dependent_configs_from |
| } |
| if (defined(invoker.include_dirs)) { |
| include_dirs = invoker.include_dirs |
| } |
| if (defined(invoker.ldflags)) { |
| ldflags = invoker.ldflags |
| } |
| if (defined(invoker.lib_dirs)) { |
| lib_dirs = invoker.lib_dirs |
| } |
| if (defined(invoker.libs)) { |
| libs = invoker.libs |
| } |
| if (defined(invoker.output_extension)) { |
| output_extension = invoker.output_extension |
| } |
| if (defined(invoker.output_name)) { |
| output_name = invoker.output_name |
| } |
| if (defined(invoker.public)) { |
| public = invoker.public |
| } |
| if (defined(invoker.public_configs)) { |
| public_configs = invoker.public_configs |
| } |
| if (defined(invoker.public_deps)) { |
| public_deps = invoker.public_deps |
| } |
| if (defined(invoker.sources)) { |
| sources = invoker.sources |
| } |
| if (defined(invoker.testonly)) { |
| testonly = invoker.testonly |
| } |
| if (defined(invoker.visibility)) { |
| visibility = invoker.visibility |
| } |
| } |
| } |