NAME

       gn - Meta-build system that generates build files for Ninja

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.  gen_deps: [label list] Declares targets
              that should generate when this  one  does.   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.

gn 1000 (0725d78)                                 January 2022                                             GN(1)