GN: Autodetect Visual Studio versions

build/toolchain/win/setup_toolchain.py

Index: build/toolchain/win/setup_toolchain.py
diff --git a/build/toolchain/win/setup_toolchain.py b/build/toolchain/win/setup_toolchain.py
index 162c2e16cef6cbd5609ad9b02c39229b5c83ecd7..bceafd121be44b6c0c2271ea8c40462937493fd7 100644
--- a/build/toolchain/win/setup_toolchain.py
+++ b/build/toolchain/win/setup_toolchain.py
@@ -2,10 +2,23 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import errno
 import os
 import re
+import subprocess
 import sys
 
+"""
+Copies the given "win tool" (which the toolchain uses to wrap compiler
+invocations) and the environment blocks for the 32-bit and 64-bit builds on
+Windows to the build directory.
+
+The arguments are the visual studio install location and the location of the
+win tool. The script assumes that the root build directory is the current dir
+and the files will be written to the current directory.
+"""
+
+
 def ExtractImportantEnvironment():
   """Extracts environment variables required for the toolchain from the
   current environment."""
@@ -36,48 +49,6 @@ def ExtractImportantEnvironment():
   return result
 
 
-# VC setup will add a path like this in 32-bit mode:
-#   c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN
-# And this in 64-bit mode:
-#   c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\amd64
-# Note that in 64-bit it's duplicated but the 64-bit one comes first.
-#
-# What we get as the path when running this will depend on which VS setup
-# script you've run. The following two functions try to do this.
-
-# For 32-bit compiles remove anything that ends in "\VC\WIN\amd64".
-def FixupPath32(path):
-  find_64 = re.compile("VC\\\\BIN\\\\amd64\\\\*$", flags=re.IGNORECASE)
-
-  for i in range(len(path)):
-    if find_64.search(path[i]):
-      # Found 32-bit path, insert the 64-bit one immediately before it.
-      dir_64 = path[i].rstrip("\\")
-      dir_64 = dir_64[:len(dir_64) - 6]  # Trim off "\amd64".
-      path[i] = dir_64
-      break
-  return path
-
-# For 64-bit compiles, append anything ending in "\VC\BIN" with "\amd64" as
-# long as that thing isn't already in the list, and append it immediately
-# before the non-amd64-one.
-def FixupPath64(path):
-  find_32 = re.compile("VC\\\\BIN\\\\*$", flags=re.IGNORECASE)
-
-  for i in range(len(path)):
-    if find_32.search(path[i]):
-      # Found 32-bit path, insert the 64-bit one immediately before it.
-      dir_32 = path[i]
-      if dir_32[len(dir_32) - 1] == '\\':
-        dir_64 = dir_32 + "amd64"
-      else:
-        dir_64 = dir_32 + "\\amd64"
-      path.insert(i, dir_64)
-      break
-
-  return path
-
-
 def FormatAsEnvironmentBlock(envvar_dict):
   """Format as an 'environment block' directly suitable for CreateProcess.
   Briefly this is a list of key=value\0, terminated by an additional \0. See
@@ -89,6 +60,7 @@ def FormatAsEnvironmentBlock(envvar_dict):
   block += nul
   return block
 
+
 def CopyTool(source_path):
   """Copies the given tool to the current directory, including a warning not
   to edit it."""
@@ -102,22 +74,27 @@ def CopyTool(source_path):
                              '# Generated by setup_toolchain.py do not edit.\n']
                             + tool_source[1:]))
 
+if len(sys.argv) != 3:
+  print 'Usage setup_toolchain.py <visual studio path> <win tool path>'
+  sys.exit(2)
+vs_path = sys.argv[1]
+tool_source = sys.argv[2]
 
-# Find the tool source, it's the first argument, and copy it.
-if len(sys.argv) != 2:
-  print "Need one argument (win_tool source path)."
-  sys.exit(1)
-CopyTool(sys.argv[1])
+CopyTool(tool_source)
 
 important_env_vars = ExtractImportantEnvironment()
 path = important_env_vars["PATH"].split(";")
 
-important_env_vars["PATH"] = ";".join(FixupPath32(path))
+# Add 32-bit compiler path to the beginning and write the block.
+path32 = [os.path.join(vs_path, "VC\\BIN")] + path
+important_env_vars["PATH"] = ";".join(path32)
 environ = FormatAsEnvironmentBlock(important_env_vars)
 with open('environment.x86', 'wb') as env_file:
   env_file.write(environ)
 
-important_env_vars["PATH"] = ";".join(FixupPath64(path))
+# Add 64-bit compiler path to the beginning and write the block.
+path64 = [os.path.join(vs_path, "VC\\BIN\\amd64")] + path
+important_env_vars["PATH"] = ";".join(path64)
 environ = FormatAsEnvironmentBlock(important_env_vars)
 with open('environment.x64', 'wb') as env_file:
   env_file.write(environ)