gn - Man Page

Documentation for GN

Description

Commands (type  gn help <command>“ for more help):”

analyze:

Analyze which targets are affected by a list of files.

args:

Display or configure arguments declared by the build.

check:

Check header dependencies.

clean:

Cleans the output directory.

clean_stale:

Cleans the stale output files from the output directory.

desc:

Show lots of insightful information about a target or config.

format:

Format .gn files.

gen:

Generate ninja files.

help:

Does what you think.

ls:

List matching targets.

meta:

List target metadata collection results.

outputs:

Which files a source/target make.

path:

Find paths between two targets.

refs:

Find stuff referencing a target or file.

Target declarations (type  gn help <function>“ for more help):”

action:

Declare a target that runs a script a single time.

action_foreach:

Declare a target that runs a script over a set of files.

bundle_data:

[iOS/macOS] Declare a target without output.

copy:

Declare a target that copies files.

create_bundle:

[iOS/macOS] Build an iOS or macOS bundle.

executable:

Declare an executable target.

generated_file:

Declare a generated_file target.

group:

Declare a named group of targets.

loadable_module:

Declare a loadable module target.

rust_library:

Declare a Rust library target.

rust_proc_macro:

Declare a Rust procedural macro target.

shared_library:

Declare a shared library target.

source_set:

Declare a source set target.

static_library:

Declare a static library target.

target:

Declare an target with the given programmatic type.

Buildfile functions (type  gn help <function>“ for more help):”

assert:

Assert an expression is true at generation time.

config:

Defines a configuration object.

declare_args:

Declare build arguments.

defined:

Returns whether an identifier is defined.

exec_script:

Synchronously run a script and return the output.

filter_exclude:

Remove values that match a set of patterns.

filter_include:

Remove values that do not match a set of patterns.

foreach:

Iterate over a list.

forward_variables_from:

Copies variables from a different scope.

get_label_info:

Get an attribute from a target's label.

get_path_info:

Extract parts of a file or directory name.

get_target_outputs:

[file list] Get the list of outputs from a target.

getenv:

Get an environment variable.

import:

Import a file into the current scope.

not_needed:

Mark variables from scope as not needed.

pool:

Defines a pool object.

print:

Prints to the console.

process_file_template:

Do template expansion over a list of files.

read_file:

Read a file into a variable.

rebase_path:

Rebase a file or directory to another location.

set_default_toolchain:

Sets the default toolchain name.

set_defaults:

Set default values for a target type.

split_list:

Splits a list into N different sub-lists.

string_join:

Concatenates a list of strings with a separator.

string_replace:

Replaces substring in the given string.

string_split:

Split string into a list of strings.

template:

Define a template rule.

tool:

Specify arguments to a toolchain tool.

toolchain:

Defines a toolchain.

write_file:

Write a file to disk.

Built-in predefined variables (type  gn help <variable>“ for more help):”

current_cpu:

[string] The processor architecture of the current toolchain.

current_os:

[string] The operating system of the current toolchain.

current_toolchain:

[string] Label of the current toolchain.

default_toolchain:

[string] Label of the default toolchain.

gn_version:

[number] The version of gn.

host_cpu:

[string] The processor architecture that GN is running on.

host_os:

[string] The operating system that GN is running on.

invoker:

[string] The invoking scope inside a template.

python_path:

[string] Absolute path of Python.

root_build_dir:

[string] Directory where build commands are run.

root_gen_dir:

[string] Directory for the toolchain's generated files.

root_out_dir:

[string] Root directory for toolchain output files.

target_cpu:

[string] The desired cpu architecture for the build.

target_gen_dir:

[string] Directory for a target's generated files.

target_name:

[string] The name of the current target.

target_os:

[string] The desired operating system for the build.

target_out_dir:

[string] Directory for target output files.

Variables you set in targets (type  gn help <variable>“ for more help):”

aliased_deps:

[scope] Set of crate-dependency pairs.

all_dependent_configs:

[label list] Configs to be forced on dependents.

allow_circular_includes_from:

[label list] Permit includes from deps.

arflags:

[string list] Arguments passed to static_library archiver.

args:

[string list] Arguments passed to an action.

asmflags:

[string list] Flags passed to the assembler.

assert_no_deps:

 [label pattern list] Ensure no deps on these targets.

bridge_header:

[string] Path to C/Objective-C compatibility header.

bundle_contents_dir:

Expansion of {{bundle_contents_dir}} in create_bundle.

bundle_deps_filter:

[label list] A list of labels that are filtered out.

bundle_executable_dir:

Expansion of {{bundle_executable_dir}} in create_bundle

bundle_resources_dir:

Expansion of {{bundle_resources_dir}} in create_bundle.

bundle_root_dir:

Expansion of {{bundle_root_dir}} in create_bundle.

cflags:

[string list] Flags passed to all C compiler variants.

cflags_c:

[string list] Flags passed to the C compiler.

cflags_cc:

[string list] Flags passed to the C++ compiler.

cflags_objc:

[string list] Flags passed to the Objective C compiler.

cflags_objcc:

[string list] Flags passed to the Objective C++ compiler.

check_includes:

[boolean] Controls whether a target's files are checked.

code_signing_args:

[string list] Arguments passed to code signing script.

code_signing_outputs:

[file list] Output files for code signing step.

code_signing_script:

[file name] Script for code signing.

code_signing_sources:

[file list] Sources for code signing step.

complete_static_lib:

[boolean] Links all deps into a static library.

configs:

[label list] Configs applying to this target or config.

contents:

Contents to write to file.

crate_name:

[string] The name for the compiled crate.

crate_root:

[string] The root source file for a binary or library.

crate_type:

[string] The type of linkage to use on a shared_library.

data:

[file list] Runtime data file dependencies.

data_deps:

[label list] Non-linked dependencies.

data_keys:

[string list] Keys from which to collect metadata.

defines:

[string list] C preprocessor defines.

depfile:

[string] File name for input dependencies for actions.

deps:

[label list] Private linked dependencies.

externs:

[scope] Set of Rust crate-dependency pairs.

framework_dirs:

[directory list] Additional framework search directories.

frameworks:

[name list] Name of frameworks that must be linked.

friend:

[label pattern list] Allow targets to include private headers.

include_dirs:

[directory list] Additional include directories.

inputs:

[file list] Additional compile-time dependencies.

ldflags:

[string list] Flags passed to the linker.

lib_dirs:

[directory list] Additional library directories.

libs:

[string list] Additional libraries to link.

metadata:

[scope] Metadata of this target.

module_name:

[string] The name for the compiled module.

output_conversion:

Data format for generated_file targets.

output_dir:

[directory] Directory to put output file in.

output_extension:

[string] Value to use for the output's file extension.

output_name:

[string] Name for the output file other than the default.

output_prefix_override:

[boolean] Don't use prefix for output name.

outputs:

[file list] Output files for actions and copy targets.

partial_info_plist:

[filename] Path plist from asset catalog compiler.

pool:

[string] Label of the pool used by the action.

precompiled_header:

[string] Header file to precompile.

precompiled_header_type:

[string] "gcc" or "msvc".

precompiled_source:

[file name] Source file to precompile.

product_type:

[string] Product type for Xcode projects.

public:

[file list] Declare public header files for a target.

public_configs:

[label list] Configs applied to dependents.

public_deps:

[label list] Declare public dependencies.

rebase:

[boolean] Rebase collected metadata as files.

response_file_contents:

[string list] Contents of .rsp file for actions.

script:

[file name] Script file for actions.

sources:

[file list] Source files for a target.

swiftflags:

[string list] Flags passed to the swift compiler.

testonly:

[boolean] Declares a target must only be used for testing.

visibility:

[label list] A list of labels that can depend on a target.

walk_keys:

[string list] Key(s) for managing the metadata collection walk.

weak_frameworks:

[name list] Name of frameworks that must be weak linked.

write_runtime_deps:

Writes the target's runtime_deps to the given path.

xcasset_compiler_flags:

[string list] Flags passed to xcassets compiler

xcode_extra_attributes:

[scope] Extra attributes for Xcode projects.

xcode_test_application_name:

[string] Name for Xcode test target.

Other help topics

all:

Print all the help at once

buildargs:

How build arguments work.

dotfile:

Info about the toplevel .gn file.

execution:

Build graph and execution overview.

grammar:

Language and grammar for GN build files.

input_conversion:

Processing input from exec_script and read_file.

file_pattern:

Matching more than one file.

label_pattern:

Matching more than one label.

labels:

About labels.

metadata_collection:

About metadata and its collection.

ninja_rules:

How Ninja build rules are named.

nogncheck:

Annotating includes for checking.

output_conversion:

Specifies how to transform a value to output.

runtime_deps:

How runtime dependency computation works.

source_expansion:

Map sources to outputs for scripts.

switches:

Show available command-line switches.

Info

April 2021 gn 1897 (dba01723)