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Diffstat (limited to 'build/moz.configure/checks.configure')
| -rw-r--r-- | build/moz.configure/checks.configure | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/build/moz.configure/checks.configure b/build/moz.configure/checks.configure new file mode 100644 index 0000000000..73e8b0a886 --- /dev/null +++ b/build/moz.configure/checks.configure @@ -0,0 +1,206 @@ +# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*- +# vim: set filetype=python: +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +# Templates implementing some generic checks. +# ============================================================== + +# Declare some exceptions. This is cumbersome, but since we shouldn't need a +# lot of them, let's stack them all here. When adding a new one, put it in the +# _declare_exceptions template, and add it to the return statement. Then +# destructure in the assignment below the function declaration. + + +@template +@imports(_from="__builtin__", _import="Exception") +def _declare_exceptions(): + class FatalCheckError(Exception): + """An exception to throw from a function decorated with @checking. + It will result in calling die() with the given message. + Debugging messages emitted from the decorated function will also be + printed out.""" + + return (FatalCheckError,) + + +(FatalCheckError,) = _declare_exceptions() + +del _declare_exceptions + +# Helper to display "checking" messages +# @checking('for foo') +# def foo(): +# return 'foo' +# is equivalent to: +# def foo(): +# log.info('checking for foo... ') +# ret = foo +# log.info(ret) +# return ret +# This can be combined with e.g. @depends: +# @depends(some_option) +# @checking('for something') +# def check(value): +# ... +# An optional callback can be given, that will be used to format the returned +# value when displaying it. + + +@template +def checking(what, callback=None): + def decorator(func): + def wrapped(*args, **kwargs): + log.info("checking %s... ", what) + with log.queue_debug(): + error, ret = None, None + try: + ret = func(*args, **kwargs) + except FatalCheckError as e: + error = str(e) + display_ret = callback(ret) if callback else ret + if display_ret is True: + log.info("yes") + elif display_ret is False or display_ret is None: + log.info("no") + else: + log.info(display_ret) + if error is not None: + die(error) + return ret + + return wrapped + + return decorator + + +# Template to check for programs in $PATH. +# - `var` is the name of the variable that will be set with `set_config` when +# the program is found. +# - `progs` is a list (or tuple) of program names that will be searched for. +# It can also be a reference to a @depends function that returns such a +# list. If the list is empty and there is no input, the check is skipped. +# - `what` is a human readable description of what is being looked for. It +# defaults to the lowercase version of `var`. +# - `input` is a string reference to an existing option or a reference to a +# @depends function resolving to explicit input for the program check. +# The default is to create an option for the environment variable `var`. +# This argument allows to use a different kind of option (possibly using a +# configure flag), or doing some pre-processing with a @depends function. +# - `allow_missing` indicates whether not finding the program is an error. +# - `paths` is a list of paths or @depends function returning a list of paths +# that will cause the given path(s) to be searched rather than $PATH. Input +# paths may either be individual paths or delimited by os.pathsep, to allow +# passing $PATH (for example) as an element. +# - `bootstrap` is a path relative to the bootstrap root path (e.g ~/.mozbuild) +# where to find the program if it's bootstrapped. +# - `validate` is a callback function that takes a path and returns True if +# the program at that location is appropriate or not, or False if not. +# when the callback returns False, check_prog ignores the program and goes +# on to the next from the `progs` list. +# +# - `bootstrap_search_path` is not an argument that users of the template are +# supposed to pass. See the override of check_prog in top-level moz.configure. +# +# The simplest form is: +# check_prog('PROG', ('a', 'b')) +# This will look for 'a' or 'b' in $PATH, and set_config PROG to the one +# it can find. If PROG is already set from the environment or command line, +# use that value instead. +@template +@imports(_from="mozbuild.shellutil", _import="quote") +def check_prog( + var, + progs, + what=None, + input=None, + allow_missing=False, + paths=None, + allow_spaces=False, + bootstrap=None, + when=None, + validate=None, + bootstrap_search_path=None, +): + if input is not None: + # Wrap input with type checking and normalization. + @depends(input, when=when) + def input(value): + if not value: + return + if isinstance(value, str): + return (value,) + if isinstance(value, (tuple, list)) and len(value) == 1: + return value + configure_error( + "input must resolve to a tuple or a list with a " + "single element, or a string" + ) + + else: + option( + env=var, + nargs=1, + when=when, + help="Path to %s" % (what or "the %s program" % var.lower()), + ) + input = var + what = what or var.lower() + + # Trick to make a @depends function out of an immediate value. + progs = dependable(progs) + paths = dependable(paths) + allow_missing = dependable(allow_missing) + + if bootstrap: + if input is var: + # A when is needed when depending on an option, so normalize + # to a function that can used without. + has_input = depends(input, when=when)(lambda x: x) + else: + has_input = input + # We don't want to bootstrap when an explicit value was given as input. + if when: + bootstrap_when = depends(when, has_input)(lambda w, i: w and not i) + else: + bootstrap_when = depends(has_input)(lambda i: not i) + paths = bootstrap_search_path(bootstrap, paths, when=bootstrap_when) + + # Avoid displaying the "Checking for" message when the inputs are such + # that we don't actually want anything to be checked. It is a bit + # convoluted because of how `when` works. + # We first wrap all the inputs except allow_missing (which doesn't count + # for whether to display the "Checking for" message). + @depends_if(input, progs, paths, when=when) + def inputs(input, progs, paths): + if progs is None: + progs = () + + if not isinstance(progs, (tuple, list)): + configure_error("progs must resolve to a list or tuple!") + + return namespace(value=input, progs=progs, paths=paths) + + @depends(inputs, allow_missing, when=inputs) + @checking("for %s" % what, lambda x: quote(x) if x else "not found") + def check(inputs, allow_missing): + value = inputs.value + progs = inputs.progs + paths = inputs.paths + + for prog in value or progs: + log.debug("%s: Looking for %s", var.lower(), quote(prog)) + result = find_program(prog, paths, allow_spaces) + if validate and result and not validate(result): + log.debug("%s: %s found but didn't work", var.lower(), quote(result)) + continue + if result: + return result + + if not allow_missing or value: + raise FatalCheckError("Cannot find %s" % what) + + set_config(var, check) + + return check |