add a helper binary for wrapping cl.exe

Modify bootstrap etc. to make use of this binary.

bootstrap.py

@@ -68,6 +68,8 @@ for src in glob.glob('src/*.cc'):
     else:
         if src.endswith('-win32.cc'):
             continue
+    if '_main' in src:
+        continue
 
     sources.append(src)
 
@@ -110,13 +112,41 @@ verbose = []
 if options.verbose:
     verbose = ['-v']
 
-print 'Building ninja using itself...'
-run([sys.executable, 'configure.py'] + conf_args)
-run(['./' + binary] + verbose)
-os.unlink(binary)
-
 if sys.platform.startswith('win32'):
+    # Build ninja-msvc-helper using ninja without an msvc-helper.
+    print 'Building ninja-msvc-helper...'
+    run([sys.executable, 'configure.py', '--with-msvc-helper='] + conf_args)
+    run(['./' + binary] + verbose + ['ninja-msvc-helper'])
+
+    # Rename the helper to the same name + .bootstrap.
+    helper_binary = 'ninja-msvc-helper.bootstrap.exe'
+    try:
+        os.unlink(helper_binary)
+    except:
+        pass
+    os.rename('ninja-msvc-helper.exe', helper_binary)
+
+    # Build ninja using the newly-built msvc-helper.
+    print 'Building ninja using itself...'
+    run([sys.executable, 'configure.py',
+         '--with-msvc-helper=%s' % helper_binary] + conf_args)
+    run(['./' + binary] + verbose)
+
+    # Clean up.
     for obj in glob.glob('*.obj'):
         os.unlink(obj)
 
-print 'Done!'
+    print """
+Done!
+
+Note: to work around Windows file locking, where you can't rebuild an
+in-use binary, to run ninja after making any changes to build ninja itself
+you should run ninja.bootstrap instead.  Your build is also configured to
+use ninja-msvc-helper.bootstrap.exe instead of the ninja-msvc-helper.exe
+that it builds; see the --help output of configure.py."""
+else:
+    print 'Building ninja using itself...'
+    run([sys.executable, 'configure.py'] + conf_args)
+    run(['./' + binary] + verbose)
+    os.unlink(binary)
+    print 'Done!'

configure.py

@@ -45,6 +45,8 @@ parser.add_option('--with-gtest', metavar='PATH',
 parser.add_option('--with-python', metavar='EXE',
                   help='use EXE as the Python interpreter',
                   default=os.path.basename(sys.executable))
+parser.add_option('--with-msvc-helper', metavar='NAME',
+                  help="name for ninja-msvc-helper binary (MSVC only)")
 (options, args) = parser.parse_args()
 if args:
     print 'ERROR: extra unparsed command-line arguments:', args
@@ -177,8 +179,11 @@ n.variable('ldflags', ' '.join(shell_escape(flag) for flag in ldflags))
 n.newline()
 
 if platform == 'windows':
+    compiler = '$cxx'
+    if options.with_msvc_helper:
+        compiler = '%s -o $out -- $cxx /showIncludes' % options.with_msvc_helper
     n.rule('cxx',
-        command='$cxx $cflags -c $in /Fo$out',
+        command='%s $cflags -c $in /Fo$out' % compiler,
         depfile='$out.d',
         description='CXX $out')
 else:
@@ -282,6 +287,16 @@ ninja = n.build(binary('ninja'), 'link', objs, implicit=ninja_lib,
 n.newline()
 all_targets += ninja
 
+if platform == 'windows':
+    n.comment('Helper for working with MSVC.')
+    msvc_helper = n.build(binary('ninja-msvc-helper'), 'link',
+                          cxx('msvc_helper_main-win32'),
+                          implicit=ninja_lib,
+                          variables=[('libs', libs)])
+    n.default(msvc_helper)
+    n.newline()
+    all_targets += msvc_helper
+
 n.comment('Tests all build into ninja_test executable.')
 
 variables = []
@@ -397,7 +412,6 @@ if host != 'mingw':
             implicit=['configure.py', os.path.normpath('misc/ninja_syntax.py')])
     n.newline()
 
-n.comment('Build only the main binary by default.')
 n.default(ninja)
 n.newline()
 

src/msvc_helper_main-win32.cc

@@ -0,0 +1,115 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "msvc_helper.h"
+
+#include <windows.h>
+
+#include "util.h"
+
+#include "getopt.h"
+
+namespace {
+
+void Usage() {
+  printf(
+"ninja-msvc-helper: adjust msvc command-line tools for use by ninja.\n"
+"\n"
+"usage: ninja-mvsc-helper [options] -- command args\n"
+"options:\n"
+"  -e ENVFILE load environment block from ENVFILE as environment\n"
+"  -r BASE    normalize paths and make relative to BASE before output\n"
+"  -o FILE    write output dependency information to FILE.d\n"
+         );
+}
+
+void PushPathIntoEnvironment(const string& env_block) {
+  const char* as_str = env_block.c_str();
+  while (as_str[0]) {
+    if (_strnicmp(as_str, "path=", 5) == 0) {
+      _putenv(as_str);
+      return;
+    } else {
+      as_str = &as_str[strlen(as_str) + 1];
+    }
+  }
+}
+
+}  // anonymous namespace
+
+int main(int argc, char** argv) {
+  const char* output_filename = NULL;
+  const char* relative_to = NULL;
+  const char* envfile = NULL;
+
+  const option kLongOptions[] = {
+    { "help", no_argument, NULL, 'h' },
+    { NULL, 0, NULL, 0 }
+  };
+  int opt;
+  while ((opt = getopt_long(argc, argv, "e:o:r:h", kLongOptions, NULL)) != -1) {
+    switch (opt) {
+      case 'e':
+        envfile = optarg;
+        break;
+      case 'o':
+        output_filename = optarg;
+        break;
+      case 'r':
+        relative_to = optarg;
+        break;
+      case 'h':
+      default:
+        Usage();
+        return 0;
+    }
+  }
+
+  if (!output_filename)
+    Fatal("-o required");
+
+  string env;
+  if (envfile) {
+    string err;
+    if (ReadFile(envfile, &env, &err) != 0)
+      Fatal("couldn't open %s: %s", envfile, err.c_str());
+    PushPathIntoEnvironment(env);
+  }
+
+  char* command = GetCommandLine();
+  command = strstr(command, " -- ");
+  if (!command) {
+    Fatal("expected command line to end with \" -- command args\"");
+  }
+  command += 4;
+
+  CLWrapper cl;
+  if (!env.empty())
+    cl.SetEnvBlock((void*)env.data());
+  int exit_code = cl.Run(command);
+
+  string depfile = string(output_filename) + ".d";
+  FILE* output = fopen(depfile.c_str(), "w");
+  if (!output) {
+    Fatal("opening %s: %s", depfile.c_str(), GetLastErrorString().c_str());
+  }
+  fprintf(output, "%s: ", output_filename);
+  for (vector<string>::iterator i = cl.includes_.begin();
+       i != cl.includes_.end(); ++i) {
+    fprintf(output, "%s\n", i->c_str());
+  }
+  fclose(output);
+
+  return exit_code;
+}