Implement a tool called link_limiter to impose a global restriction on how many

tools/win/link_limiter/build_link_limiter.py

+#!/usr/bin/env python
+# 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.
+
+import glob
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+BUILD_DIR = 'build'
+
+
+def run_with_vsvars(cmd, tmpdir=None):
+  fd, filename = tempfile.mkstemp('.bat', text=True)
+  with os.fdopen(fd, 'w') as f:
+    print >> f, '@echo off'
+    print >> f, r'call "%VS100COMNTOOLS%\vsvars32.bat"'
+    if tmpdir:
+      print >> f, r'cd %s' % tmpdir
+    print >> f, cmd
+  try:
+    p = subprocess.Popen([filename], shell=True, stdout=subprocess.PIPE,
+        universal_newlines=True)
+    out, _ = p.communicate()
+    return p.returncode, out
+  finally:
+    os.unlink(filename)
+
+
+def get_vc_dir():
+  _, out = run_with_vsvars('echo VCINSTALLDIR=%VCINSTALLDIR%')
+  for line in out.splitlines():  # pylint: disable-msg=E1103
+    if line.startswith('VCINSTALLDIR='):
+      return line[len('VCINSTALLDIR='):]
+  return None
+
+
+def build(infile):
+  if not os.path.exists(BUILD_DIR):
+    os.makedirs(BUILD_DIR)
+  outfile = 'limiter.exe'
+  outpath = os.path.join(BUILD_DIR, outfile)
+  cpptime = os.path.getmtime(infile)
+  if not os.path.exists(outpath) or cpptime > os.path.getmtime(outpath):
+    print 'Building %s...' % outfile
+    rc, out = run_with_vsvars(
+        'cl /nologo /Ox /Zi /W4 /WX /D_UNICODE /DUNICODE'
+        ' /D_CRT_SECURE_NO_WARNINGS /EHsc %s /link /out:%s'
+        % (os.path.join('..', infile), outfile), BUILD_DIR)
+    if rc:
+      print out
+      print 'Failed to build %s' % outfile
+      sys.exit(1)
+  else:
+    print '%s already built' % outfile
+  return outpath
+
+
+def main():
+  # Switch to our own dir.
+  os.chdir(os.path.dirname(os.path.abspath(__file__)))
+
+  if sys.argv[-1] == 'clean':
+    if os.path.exists(BUILD_DIR):
+      shutil.rmtree(BUILD_DIR)
+    for exe in glob.glob('*.exe'):
+      os.unlink(exe)
+    return 0
+
+  vcdir = os.environ.get('VCINSTALLDIR')
+  if not vcdir:
+    vcdir = get_vc_dir()
+    if not vcdir:
+      print "Couldn't get VCINSTALLDIR. Run vsvars32.bat?"

[cmp, 2012/08/01 23:36:42]

nit: single quotes

[iannucci1, 2012/08/01 23:52:39]

even for the contained "'"? 

[cmp, 2012/08/02 00:00:04]

Thanks for pointing that out, I overlooked it.  I'll say a little more to give
you more background.

I tend to expand contractions to avoid contained single quotes.  If that's easy
for you to change, please do that.

I've also seen strict adherence to single quotes and then contained single
quotes being escaped.

You're probably wondering where the line is on this, or if there is one.  There
is, and it's when contained single quotes really get in the way and require a
bunch of escaping that makes the code hard to read.  A good example of this is
when defining regular expressions that match on single quotes.

+      return 1
+    os.environ['PATH'] += (';' + os.path.join(vcdir, 'bin') +
+                           ';' + os.path.join(vcdir, r'..\Common7\IDE'))
+
+  # Verify that we can find link.exe.
+  link = os.path.join(vcdir, 'bin', 'link.exe')
+  if not os.path.exists(link):
+    print 'link.exe not found at %s' % link
+    return 1
+
+  exe_name = build('limiter.cc')
+  for shim_exe in ('lib.exe', 'link.exe'):
+    newpath = '%s__LIMITER.exe' % shim_exe
+    shutil.copyfile(exe_name, newpath)
+    print '%s shim built. Use with msbuild like: "/p:LinkToolExe=%s"' \
+        % (shim_exe, os.path.abspath(newpath))
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())