1 # -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
2 # vim: set filetype=python:
3 # This Source Code Form is subject to the terms of the Mozilla Public
4 # License, v. 2.0. If a copy of the MPL was not distributed with this
5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
7 # Templates implementing some generic checks.
8 # ==============================================================
10 # Declare some exceptions. This is cumbersome, but since we shouldn't need a
11 # lot of them, let's stack them all here. When adding a new one, put it in the
12 # _declare_exceptions template, and add it to the return statement. Then
13 # destructure in the assignment below the function declaration.
17 @imports(_from="__builtin__", _import="Exception")
18 def _declare_exceptions():
19 class FatalCheckError(Exception):
20 """An exception to throw from a function decorated with @checking.
21 It will result in calling die() with the given message.
22 Debugging messages emitted from the decorated function will also be
25 return (FatalCheckError,)
28 (FatalCheckError,) = _declare_exceptions()
30 del _declare_exceptions
32 # Helper to display "checking" messages
33 # @checking('for foo')
38 # log.info('checking for foo... ')
42 # This can be combined with e.g. @depends:
43 # @depends(some_option)
44 # @checking('for something')
47 # An optional callback can be given, that will be used to format the returned
48 # value when displaying it.
52 def checking(what, callback=None):
54 def wrapped(*args, **kwargs):
55 log.info("checking %s... ", what)
56 with log.queue_debug():
57 error, ret = None, None
59 ret = func(*args, **kwargs)
60 except FatalCheckError as e:
62 display_ret = callback(ret) if callback else ret
63 if display_ret is True:
65 elif display_ret is False or display_ret is None:
78 # Template to check for programs in $PATH.
79 # - `var` is the name of the variable that will be set with `set_config` when
80 # the program is found.
81 # - `progs` is a list (or tuple) of program names that will be searched for.
82 # It can also be a reference to a @depends function that returns such a
83 # list. If the list is empty and there is no input, the check is skipped.
84 # - `what` is a human readable description of what is being looked for. It
85 # defaults to the lowercase version of `var`.
86 # - `input` is a string reference to an existing option or a reference to a
87 # @depends function resolving to explicit input for the program check.
88 # The default is to create an option for the environment variable `var`.
89 # This argument allows to use a different kind of option (possibly using a
90 # configure flag), or doing some pre-processing with a @depends function.
91 # - `allow_missing` indicates whether not finding the program is an error.
92 # - `paths` is a list of paths or @depends function returning a list of paths
93 # that will cause the given path(s) to be searched rather than $PATH. Input
94 # paths may either be individual paths or delimited by os.pathsep, to allow
95 # passing $PATH (for example) as an element.
96 # - `bootstrap` is a path relative to the bootstrap root path (e.g ~/.mozbuild)
97 # where to find the program if it's bootstrapped.
98 # - `validate` is a callback function that takes a path and returns True if
99 # the program at that location is appropriate or not, or False if not.
100 # when the callback returns False, check_prog ignores the program and goes
101 # on to the next from the `progs` list.
103 # - `bootstrap_search_path` is not an argument that users of the template are
104 # supposed to pass. See the override of check_prog in top-level moz.configure.
106 # The simplest form is:
107 # check_prog('PROG', ('a', 'b'))
108 # This will look for 'a' or 'b' in $PATH, and set_config PROG to the one
109 # it can find. If PROG is already set from the environment or command line,
110 # use that value instead.
112 @imports(_from="mozbuild.shellutil", _import="quote")
124 bootstrap_search_path=None,
126 if input is not None:
127 # Wrap input with type checking and normalization.
128 @depends(input, when=when)
132 if isinstance(value, str):
134 if isinstance(value, (tuple, list)) and len(value) == 1:
137 "input must resolve to a tuple or a list with a "
138 "single element, or a string"
146 help="Path to %s" % (what or "the %s program" % var.lower()),
149 what = what or var.lower()
151 # Trick to make a @depends function out of an immediate value.
152 progs = dependable(progs)
153 paths = dependable(paths)
154 allow_missing = dependable(allow_missing)
158 # A when is needed when depending on an option, so normalize
159 # to a function that can used without.
160 has_input = depends(input, when=when)(lambda x: x)
163 # We don't want to bootstrap when an explicit value was given as input.
165 bootstrap_when = depends(when, has_input)(lambda w, i: w and not i)
167 bootstrap_when = depends(has_input)(lambda i: not i)
168 paths = bootstrap_search_path(bootstrap, paths, when=bootstrap_when)
170 # Avoid displaying the "Checking for" message when the inputs are such
171 # that we don't actually want anything to be checked. It is a bit
172 # convoluted because of how `when` works.
173 # We first wrap all the inputs except allow_missing (which doesn't count
174 # for whether to display the "Checking for" message).
175 @depends_if(input, progs, paths, when=when)
176 def inputs(input, progs, paths):
180 if not isinstance(progs, (tuple, list)):
181 configure_error("progs must resolve to a list or tuple!")
183 return namespace(value=input, progs=progs, paths=paths)
185 @depends(inputs, allow_missing, when=inputs)
186 @checking("for %s" % what, lambda x: quote(x) if x else "not found")
187 def check(inputs, allow_missing):
192 for prog in value or progs:
193 log.debug("%s: Looking for %s", var.lower(), quote(prog))
194 result = find_program(prog, paths, allow_spaces)
195 if validate and result and not validate(result):
196 log.debug("%s: %s found but didn't work", var.lower(), quote(result))
201 if not allow_missing or value:
202 raise FatalCheckError("Cannot find %s" % what)
204 set_config(var, check)