GN: Change gen command syntax, support relative dirs.

tools/gn/setup.cc

 // Copyright (c) 2013 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.
 
 #include "tools/gn/setup.h"
 
 #include <stdlib.h>
 
 #include <algorithm>
 
@@ skipping 66 matching lines @@
 const char kSwitchArgs[] = "args";
 
 // Set root dir.
 const char kSwitchRoot[] = "root";
 
 // Enable timing.
 const char kTimeSwitch[] = "time";
 
 const char kTracelogSwitch[] = "tracelog";
 
-// Set build output directory.
-const char kSwitchBuildOutput[] = "output";
-
 const char kSecondarySource[] = "secondary";
 
 const base::FilePath::CharType kGnFile[] = FILE_PATH_LITERAL(".gn");
 
 base::FilePath FindDotFile(const base::FilePath& current_dir) {
   base::FilePath try_this_file = current_dir.Append(kGnFile);
   if (base::PathExists(try_this_file))
     return try_this_file;
 
   base::FilePath with_no_slash = current_dir.StripTrailingSeparators();
@@ skipping 89 matching lines @@
       base::Bind(&ItemDefinedCallback, scheduler_.main_loop(), builder_));
 
   // The scheduler's main loop wasn't created when the Loader was created, so
   // we need to set it now.
   loader_->set_main_loop(scheduler_.main_loop());
 }
 
 Setup::~Setup() {
 }
 
-bool Setup::DoSetup() {
+bool Setup::DoSetup(const std::string& build_dir) {
   CommandLine* cmdline = CommandLine::ForCurrentProcess();
 
   scheduler_.set_verbose_logging(cmdline->HasSwitch(kSwitchVerbose));
   if (cmdline->HasSwitch(kTimeSwitch) ||
       cmdline->HasSwitch(kTracelogSwitch))
     EnableTracing();
 
   if (!FillArguments(*cmdline))
     return false;
   if (!FillSourceDir(*cmdline))
     return false;
   if (!RunConfigFile())
     return false;
   if (!FillOtherConfig(*cmdline))
     return false;
+  if (!FillBuildDir(build_dir))  // Must be after FillSourceDir to resolve.
+    return false;
   FillPythonPath();
 
-  base::FilePath build_path = cmdline->GetSwitchValuePath(kSwitchBuildOutput);
-  if (!build_path.empty()) {
-    // We accept either repo paths "//out/Debug" or raw source-root-relative
-    // paths "out/Debug".
-    std::string build_path_8 = FilePathToUTF8(build_path);
-    if (build_path_8.compare(0, 2, "//") != 0)
-      build_path_8.insert(0, "//");
-#if defined(OS_WIN)
-    // Canonicalize to forward slashes on Windows.
-    std::replace(build_path_8.begin(), build_path_8.end(), '\\', '/');
-#endif
-    build_settings_.SetBuildDir(SourceDir(build_path_8));
-  } else {
-    // Default output dir.
-    build_settings_.SetBuildDir(SourceDir("//out/Default/"));
-  }
-
   return true;
 }
 
 bool Setup::Run() {
   RunPreMessageLoop();
   if (!scheduler_.Run())
     return false;
   return RunPostMessageLoop();
 }
 
@@ skipping 60 matching lines @@
     root_path = dotfile_name_.DirName();
   }
 
   if (scheduler_.verbose_logging())
     scheduler_.Log("Using source root", FilePathToUTF8(root_path));
   build_settings_.SetRootPath(root_path);
 
   return true;
 }
 
+bool Setup::FillBuildDir(const std::string& build_dir) {
+  SourceDir resolved =
+      SourceDirForCurrentDirectory(build_settings_.root_path()).
+          ResolveRelativeDir(build_dir);
+  if (resolved.is_null()) {
+    Err(Location(), "Couldn't resolve build directory.",
+        "The build directory supplied (\"" + build_dir + "\") was not valid.").
+        PrintToStdout();
+    return false;
+  }
+
+  if (scheduler_.verbose_logging())
+    scheduler_.Log("Using build dir", resolved.value());
+  build_settings_.SetBuildDir(resolved);
+  return true;
+}
+
 void Setup::FillPythonPath() {
 #if defined(OS_WIN)
   // Find Python on the path so we can use the absolute path in the build.
   const base::char16 kGetPython[] =
       L"cmd.exe /c python -c \"import sys; print sys.executable\"";
   std::string python_path;
   if (base::GetAppOutput(kGetPython, &python_path)) {
     TrimWhitespaceASCII(python_path, TRIM_ALL, &python_path);
     if (scheduler_.verbose_logging())
       scheduler_.Log("Found python", python_path);
@@ skipping 108 matching lines @@
 }
 
 void DependentSetup::RunPreMessageLoop() {
   CommonSetup::RunPreMessageLoop();
 }
 
 bool DependentSetup::RunPostMessageLoop() {
   return CommonSetup::RunPostMessageLoop();
 }