config/expandlibs.py
author Chris H-C <chutten@mozilla.com>
Mon, 04 Jul 2016 11:16:05 -0400
changeset 312997 df28918fe2361f0b54ca9ce4773a29c4c0675d06
parent 208804 d959a6081ceacde13d41b8a4ee192c912c85ef02
permissions -rw-r--r--
bug 1218576 - Support remote accumulation via JS histograms. r=gfritzsche The JS histograms, too, need to dispatch their accumulations from child to parent. JSHistograms_Add now only supports histograms that are in gHistogramsMap or that were created in the parent process. After bug 1288745, maybe we'll be able to change this to be less convoluted. MozReview-Commit-ID: 3qTH89YKbGP

# 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/.

'''Expandlibs is a system that allows to replace some libraries with a
descriptor file containing some linking information about them.

The descriptor file format is as follows:
---8<-----
OBJS = a.o b.o ...
LIBS = libfoo.a libbar.a ...
--->8-----

(In the example above, OBJ_SUFFIX is o and LIB_SUFFIX is a).

Expandlibs also canonicalizes how to pass libraries to the linker, such
that only the ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} form needs to be used:
given a list of files, expandlibs will replace items with the form
${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} following these rules:

- If a ${DLL_PREFIX}${ROOT}.${DLL_SUFFIX} or
  ${DLL_PREFIX}${ROOT}.${IMPORT_LIB_SUFFIX} file exists, use that instead
- If the ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} file exists, use it
- If a ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX}.${LIB_DESC_SUFFIX} file exists,
  replace ${LIB_PREFIX}${ROOT}.${LIB_SUFFIX} with the OBJS and LIBS the
  descriptor contains. And for each of these LIBS, also apply the same
  rules.
'''
from __future__ import with_statement
import sys, os, errno
import expandlibs_config as conf

def ensureParentDir(file):
    '''Ensures the directory parent to the given file exists'''
    dir = os.path.dirname(file)
    if dir and not os.path.exists(dir):
        try:
            os.makedirs(dir)
        except OSError, error:
            if error.errno != errno.EEXIST:
                raise

def relativize(path):
    '''Returns a path relative to the current working directory, if it is
    shorter than the given path'''
    def splitpath(path):
        dir, file = os.path.split(path)
        if os.path.splitdrive(dir)[1] == os.sep:
            return [file]
        return splitpath(dir) + [file]

    if not os.path.exists(path):
        return path
    curdir = splitpath(os.path.abspath(os.curdir))
    abspath = splitpath(os.path.abspath(path))
    while curdir and abspath and curdir[0] == abspath[0]:
        del curdir[0]
        del abspath[0]
    if not curdir and not abspath:
        return '.'
    relpath = os.path.join(*[os.pardir for i in curdir] + abspath)
    if len(path) > len(relpath):
        return relpath
    return path

def isObject(path):
    '''Returns whether the given path points to an object file, that is,
    ends with OBJ_SUFFIX or .i_o'''
    return os.path.splitext(path)[1] in [conf.OBJ_SUFFIX, '.i_o']

def isDynamicLib(path):
    '''Returns whether the given path points to a dynamic library, that is,
    ends with DLL_SUFFIX.'''
    # On mac, the xul library is named XUL, instead of libxul.dylib. Assume any
    # file by that name is a dynamic library.
    return os.path.splitext(path)[1] == conf.DLL_SUFFIX or os.path.basename(path) == 'XUL'

class LibDescriptor(dict):
    KEYS = ['OBJS', 'LIBS']

    def __init__(self, content=None):
        '''Creates an instance of a lib descriptor, initialized with contents
        from a list of strings when given. This is intended for use with
        file.readlines()'''
        if isinstance(content, list) and all([isinstance(item, str) for item in content]):
            pass
        elif content is not None:
            raise TypeError("LibDescriptor() arg 1 must be None or a list of strings")
        super(LibDescriptor, self).__init__()
        for key in self.KEYS:
            self[key] = []
        if not content:
            return
        for key, value in [(s.strip() for s in item.split('=', 2)) for item in content if item.find('=') >= 0]:
            if key in self.KEYS:
                self[key] = value.split()

    def __str__(self):
        '''Serializes the lib descriptor'''
        return '\n'.join('%s = %s' % (k, ' '.join(self[k])) for k in self.KEYS if len(self[k]))

class ExpandArgs(list):
    def __init__(self, args):
        '''Creates a clone of the |args| list and performs file expansion on
        each item it contains'''
        super(ExpandArgs, self).__init__()
        self._descs = set()
        for arg in args:
            self += self._expand(arg)

    def _expand(self, arg):
        '''Internal function doing the actual work'''
        (root, ext) = os.path.splitext(arg)
        if ext != conf.LIB_SUFFIX or not os.path.basename(root).startswith(conf.LIB_PREFIX):
            return [relativize(arg)]
        if conf.LIB_PREFIX:
            dll = root.replace(conf.LIB_PREFIX, conf.DLL_PREFIX, 1) + conf.DLL_SUFFIX
        else:
            dll = root + conf.DLL_SUFFIX
        if os.path.exists(dll):
            if conf.IMPORT_LIB_SUFFIX:
                return [relativize(root + conf.IMPORT_LIB_SUFFIX)]
            else:
                return [relativize(dll)]
        return self._expand_desc(arg)

    def _expand_desc(self, arg):
        '''Internal function taking care of lib descriptor expansion only'''
        desc = os.path.abspath(arg + conf.LIBS_DESC_SUFFIX)
        if os.path.exists(desc):
            if desc in self._descs:
                return []
            self._descs.add(desc)
            with open(desc, 'r') as f:
                desc = LibDescriptor(f.readlines())
            objs = [relativize(o) for o in desc['OBJS']]
            for lib in desc['LIBS']:
                objs += self._expand(lib)
            return objs
        return [relativize(arg)]

if __name__ == '__main__':
    print " ".join(ExpandArgs(sys.argv[1:]))