docs

Basic syntax

# examples/hello_world/build.hancho

compile = Rule(
  desc = "Compile {files_in} -> {files_out}",
  command = "g++ -MMD -c {files_in} -o {files_out}",
  files_out = "{swap_ext(files_in, '.o')}",
  depfile = "{swap_ext(files_out, '.d')}",
)

link = Rule(
  desc = "Link {files_in} -> {files_out}",
  command = "g++ {files_in} -o {files_out}",
)

main_o = compile("main.cpp")
main_app = link(main_o, "app")

Special fields in hancho.Rule()

• base (Default: hancho.config)
  • The rule this rule inherits from. Reading missing fields from a rule will check rule.base for the field if there is one, otherwise the missing field will read as None
• build_dir (Default: build)
  • The directory to put output files in.
• command (Default: None)
  • The console command this rule should run, or
  • An asynchronous function that returns a list of absolute-path filenames.
• debug (Default: False)
  • True if this rule should print debug information when run
• depfile (Default: None)
  • A GCC format dependencies file
• deps (Default: None)
  • A list of files this rule depends on to run that are not input files.
• desc (Default: "{files_in} -> {files_out}")
  • A description of what this rule does that will be printed when run.
• dryrun (Default: False)
  • True if this rule should pretend to succeed, but actually do nothing.
• files_in (Default: [])
  • The list of files (or file promises) this rule accepts as input.
• files_out (Default: [])
  • The list of files this rule generates as output
• force (Default: False)
  • True if this rule should always run.
• meta_deps (Default: Autogenerated)
  • The list of .hancho files that were in scope when this rule was run.
  • Used to rebuilt targets when .hancho files change.
• quiet (Default: False)
  • True if Hancho should print no output when run. Overrides verbose
• verbose (Default: False)
  • True if Hancho should print command lines and rebuild reasons when run.
• jobs (Default: os.cpu_count())
  • The number of console commands Hancho will run in parallel.

Helper methods defined in hancho.config:

• expand(rule, string)
  • Converts a template string to a normal string by replacing {}s in the string with values taken from rule.
• join([strings])
  • Joins a list of strings with spaces, used to pass lists of files to console commands
• len([list])
  • Same as Python's len()
• run_cmd(command)
  • Runs a console command synchronously and returns its stdout with whitespace stripped. Used to inject text into other console commands.
• swap_ext(filename, suffix)
  • Replaces a file's suffix with the given one. Used for converting foo.c to foo.o, etcetera.
• color()
  • Changes the color of text printed to stdout. Used for color-coding of build rules.