# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Utility functions for Windows builds.

This file is copied to the build directory as part of toolchain setup and
is used to set up calls to tools used by the build that need wrappers.
"""

import os
import re
import shutil
import subprocess
import stat
import string
import sys

BASE_DIR = os.path.dirname(os.path.abspath(__file__))

# A regex matching an argument corresponding to the output filename passed to
# link.exe.
_LINK_EXE_OUT_ARG = re.compile('/OUT:(?P<out>.+)$', re.IGNORECASE)

def main(args):
  executor = WinTool()
  exit_code = executor.Dispatch(args)
  if exit_code is not None:
    sys.exit(exit_code)


class WinTool(object):
  """This class performs all the Windows tooling steps. The methods can either
  be executed directly, or dispatched from an argument list."""

  def _UseSeparateMspdbsrv(self, env, args):
    """Allows to use a unique instance of mspdbsrv.exe per linker instead of a
    shared one."""
    if len(args) < 1:
      raise Exception("Not enough arguments")

    if args[0] != 'link.exe':
      return

    # Use the output filename passed to the linker to generate an endpoint name
    # for mspdbsrv.exe.
    endpoint_name = None
    for arg in args:
      m = _LINK_EXE_OUT_ARG.match(arg)
      if m:
        endpoint_name = re.sub(r'\W+', '',
            '%s_%d' % (m.group('out'), os.getpid()))
        break

    if endpoint_name is None:
      return

    # Adds the appropriate environment variable. This will be read by link.exe
    # to know which instance of mspdbsrv.exe it should connect to (if it's
    # not set then the default endpoint is used).
    env['_MSPDBSRV_ENDPOINT_'] = endpoint_name

  def Dispatch(self, args):
    """Dispatches a string command to a method."""
    if len(args) < 1:
      raise Exception("Not enough arguments")

    method = "Exec%s" % self._CommandifyName(args[0])
    return getattr(self, method)(*args[1:])

  def _CommandifyName(self, name_string):
    """Transforms a tool name like recursive-mirror to RecursiveMirror."""
    return name_string.title().replace('-', '')

  def _GetEnv(self, arch):
    """Gets the saved environment from a file for a given architecture."""
    # The environment is saved as an "environment block" (see CreateProcess
    # and msvs_emulation for details). We convert to a dict here.
    # Drop last 2 NULs, one for list terminator, one for trailing vs. separator.
    pairs = open(arch).read()[:-2].split('\0')
    kvs = [item.split('=', 1) for item in pairs]
    return dict(kvs)

  def ExecStamp(self, path):
    """Simple stamp command."""
    open(path, 'w').close()

  def ExecRecursiveMirror(self, source, dest):
    """Emulation of rm -rf out && cp -af in out."""
    if os.path.exists(dest):
      if os.path.isdir(dest):
        def _on_error(fn, path, dummy_excinfo):
          # The operation failed, possibly because the file is set to
          # read-only. If that's why, make it writable and try the op again.
          if not os.access(path, os.W_OK):
            os.chmod(path, stat.S_IWRITE)
          fn(path)
        shutil.rmtree(dest, onerror=_on_error)
      else:
        if not os.access(dest, os.W_OK):
          # Attempt to make the file writable before deleting it.
          os.chmod(dest, stat.S_IWRITE)
        os.unlink(dest)

    if os.path.isdir(source):
      shutil.copytree(source, dest)
    else:
      shutil.copy2(source, dest)

  def ExecLinkWrapper(self, arch, use_separate_mspdbsrv, *args):
    """Filter diagnostic output from link that looks like:
    '   Creating library ui.dll.lib and object ui.dll.exp'
    This happens when there are exports from the dll or exe.
    """
    env = self._GetEnv(arch)
    if use_separate_mspdbsrv == 'True':
      self._UseSeparateMspdbsrv(env, args)
    if sys.platform == 'win32':
      args = list(args)  # *args is a tuple by default, which is read-only.
      args[0] = args[0].replace('/', '\\')
    # https://docs.python.org/2/library/subprocess.html:
    # "On Unix with shell=True [...] if args is a sequence, the first item
    # specifies the command string, and any additional items will be treated as
    # additional arguments to the shell itself.  That is to say, Popen does the
    # equivalent of:
    #   Popen(['/bin/sh', '-c', args[0], args[1], ...])"
    # For that reason, since going through the shell doesn't seem necessary on
    # non-Windows don't do that there.
    link = subprocess.Popen(args, shell=sys.platform == 'win32', env=env,
                            stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    out, _ = link.communicate()
    for line in out.splitlines():
      if (not line.startswith('   Creating library ') and
          not line.startswith('Generating code') and
          not line.startswith('Finished generating code')):
        print line
    return link.returncode

  def ExecLinkWithManifests(self, arch, embed_manifest, out, ldcmd, resname,
                            mt, rc, intermediate_manifest, *manifests):
    """A wrapper for handling creating a manifest resource and then executing
    a link command."""
    # The 'normal' way to do manifests is to have link generate a manifest
    # based on gathering dependencies from the object files, then merge that
    # manifest with other manifests supplied as sources, convert the merged
    # manifest to a resource, and then *relink*, including the compiled
    # version of the manifest resource. This breaks incremental linking, and
    # is generally overly complicated. Instead, we merge all the manifests
    # provided (along with one that includes what would normally be in the
    # linker-generated one, see msvs_emulation.py), and include that into the
    # first and only link. We still tell link to generate a manifest, but we
    # only use that to assert that our simpler process did not miss anything.
    variables = {
      'python': sys.executable,
      'arch': arch,
      'out': out,
      'ldcmd': ldcmd,
      'resname': resname,
      'mt': mt,
      'rc': rc,
      'intermediate_manifest': intermediate_manifest,
      'manifests': ' '.join(manifests),
    }
    add_to_ld = ''
    if manifests:
      subprocess.check_call(
          '%(python)s tool_wrapper.py manifest-wrapper %(arch)s %(mt)s -nologo '
          '-manifest %(manifests)s -out:%(out)s.manifest' % variables)
      if embed_manifest == 'True':
        subprocess.check_call(
            '%(python)s tool_wrapper.py manifest-to-rc %(arch)s'
                '%(out)s.manifest %(out)s.manifest.rc %(resname)s' % variables)
        subprocess.check_call(
            '%(python)s tool_wrapper.py rc-wrapper %(arch)s %(rc)s '
            '%(out)s.manifest.rc' % variables)
        add_to_ld = ' %(out)s.manifest.res' % variables
    subprocess.check_call(ldcmd + add_to_ld)

    # Run mt.exe on the theoretically complete manifest we generated, merging
    # it with the one the linker generated to confirm that the linker
    # generated one does not add anything. This is strictly unnecessary for
    # correctness, it's only to verify that e.g. /MANIFESTDEPENDENCY was not
    # used in a #pragma comment.
    if manifests:
      # Merge the intermediate one with ours to .assert.manifest, then check
      # that .assert.manifest is identical to ours.
      subprocess.check_call(
          '%(python)s tool_wrapper.py manifest-wrapper %(arch)s %(mt)s -nologo '
          '-manifest %(out)s.manifest %(intermediate_manifest)s '
          '-out:%(out)s.assert.manifest' % variables)
      assert_manifest = '%(out)s.assert.manifest' % variables
      our_manifest = '%(out)s.manifest' % variables
      # Load and normalize the manifests. mt.exe sometimes removes whitespace,
      # and sometimes doesn't unfortunately.
      with open(our_manifest, 'rb') as our_f:
        with open(assert_manifest, 'rb') as assert_f:
          our_data = our_f.read().translate(None, string.whitespace)
          assert_data = assert_f.read().translate(None, string.whitespace)
      if our_data != assert_data:
        os.unlink(out)
        def dump(filename):
          sys.stderr.write('%s\n-----\n' % filename)
          with open(filename, 'rb') as f:
            sys.stderr.write(f.read() + '\n-----\n')
        dump(intermediate_manifest)
        dump(our_manifest)
        dump(assert_manifest)
        sys.stderr.write(
            'Linker generated manifest "%s" added to final manifest "%s" '
            '(result in "%s"). '
            'Were /MANIFEST switches used in #pragma statements? ' % (
              intermediate_manifest, our_manifest, assert_manifest))
        return 1

  def ExecManifestWrapper(self, arch, *args):
    """Run manifest tool with environment set. Strip out undesirable warning
    (some XML blocks are recognized by the OS loader, but not the manifest
    tool)."""
    env = self._GetEnv(arch)
    popen = subprocess.Popen(args, shell=True, env=env,
                             stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    out, _ = popen.communicate()
    for line in out.splitlines():
      if line and 'manifest authoring warning 81010002' not in line:
        print line
    return popen.returncode

  def ExecManifestToRc(self, dummy_arch, *args):
    """Creates a resource file pointing a SxS assembly manifest.
    |args| is tuple containing path to resource file, path to manifest file
    and resource name which can be "1" (for executables) or "2" (for DLLs)."""
    manifest_path, resource_path, resource_name = args
    with open(resource_path, 'wb') as output:
      output.write('#include <windows.h>\n%s RT_MANIFEST "%s"' % (
        resource_name,
        os.path.abspath(manifest_path).replace('\\', '/')))

  def ExecMidlWrapper(self, arch, outdir, tlb, h, dlldata, iid, proxy, idl,
                      *flags):
    """Filter noisy filenames output from MIDL compile step that isn't
    quietable via command line flags.
    """
    args = ['midl', '/nologo'] + list(flags) + [
        '/out', outdir,
        '/tlb', tlb,
        '/h', h,
        '/dlldata', dlldata,
        '/iid', iid,
        '/proxy', proxy,
        idl]
    env = self._GetEnv(arch)
    popen = subprocess.Popen(args, shell=True, env=env,
                             stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    out, _ = popen.communicate()
    # Filter junk out of stdout, and write filtered versions. Output we want
    # to filter is pairs of lines that look like this:
    # Processing C:\Program Files (x86)\Microsoft SDKs\...\include\objidl.idl
    # objidl.idl
    lines = out.splitlines()
    prefixes = ('Processing ', '64 bit Processing ')
    processing = set(os.path.basename(x)
                     for x in lines if x.startswith(prefixes))
    for line in lines:
      if not line.startswith(prefixes) and line not in processing:
        print line
    return popen.returncode

  def ExecAsmWrapper(self, arch, *args):
    """Filter logo banner from invocations of asm.exe."""
    env = self._GetEnv(arch)
    popen = subprocess.Popen(args, shell=True, env=env,
                             stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    out, _ = popen.communicate()
    for line in out.splitlines():
      # Split to avoid triggering license checks:
      if (not line.startswith('Copy' + 'right (C' +
                              ') Microsoft Corporation') and
          not line.startswith('Microsoft (R) Macro Assembler') and
          not line.startswith(' Assembling: ') and
          line):
        print line
    return popen.returncode

  def ExecRcWrapper(self, arch, *args):
    """Filter logo banner from invocations of rc.exe. Older versions of RC
    don't support the /nologo flag."""
    env = self._GetEnv(arch)
    popen = subprocess.Popen(args, shell=True, env=env,
                             stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    out, _ = popen.communicate()
    for line in out.splitlines():
      if (not line.startswith('Microsoft (R) Windows (R) Resource Compiler') and
          not line.startswith('Copy' + 'right (C' +
                              ') Microsoft Corporation') and
          line):
        print line
    return popen.returncode

  def ExecActionWrapper(self, arch, rspfile, *dirname):
    """Runs an action command line from a response file using the environment
    for |arch|. If |dirname| is supplied, use that as the working directory."""
    env = self._GetEnv(arch)
    # TODO(scottmg): This is a temporary hack to get some specific variables
    # through to actions that are set after GN-time. http://crbug.com/333738.
    for k, v in os.environ.iteritems():
      if k not in env:
        env[k] = v
    args = open(rspfile).read()
    dirname = dirname[0] if dirname else None
    return subprocess.call(args, shell=True, env=env, cwd=dirname)

  def ExecClCompile(self, project_dir, selected_files):
    """Executed by msvs-ninja projects when the 'ClCompile' target is used to
    build selected C/C++ files."""
    project_dir = os.path.relpath(project_dir, BASE_DIR)
    selected_files = selected_files.split(';')
    ninja_targets = [os.path.join(project_dir, filename) + '^^'
        for filename in selected_files]
    cmd = ['ninja.exe']
    cmd.extend(ninja_targets)
    return subprocess.call(cmd, shell=True, cwd=BASE_DIR)

if __name__ == '__main__':
  sys.exit(main(sys.argv[1:]))
