Make sure abs-path gn labels have separate target_gen_dirs

tools/gn/filesystem_utils.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/filesystem_utils.h"
 
 #include <algorithm>
 
 #include "base/files/file_util.h"
 #include "base/logging.h"
@@ skipping 668 matching lines @@
   return SourceDir(SourceDir::SWAP_IN, &result);
 }
 
 SourceDir GetOutputDirForSourceDir(const Settings* settings,
                                    const SourceDir& source_dir) {
   return GetOutputDirForSourceDir(
       settings->build_settings(), source_dir,
       settings->toolchain_label(), settings->is_default());
 }
 
+void AppendFixedAbsolutePathSuffix(const BuildSettings *build_settings,

[brettw, 2015/10/26 00:36:52]

Nit: * next to type instead like your other ones.

+                                   const SourceDir& source_dir,
+                                   OutputFile* result) {
+  const std::string& build_dir = build_settings->build_dir().value();
+
+  if (base::StartsWith(source_dir.value(), build_dir,
+                       base::CompareCase::SENSITIVE)) {
+    size_t build_dir_size = build_dir.size();
+    result->value().append(&source_dir.value()[build_dir_size],
+                           source_dir.value().size() - build_dir_size);
+  } else {
+    result->value().append("ABS_PATH");
+#if defined(OS_WIN)
+    // Windows absolute path contains ':' after drive letter. Remove it to
+    // avoid inserting ':' in the middle of path (eg. "ABS_PATH/C:/").
+    std::string src_dir_value = source_dir.value();
+    const auto colon_pos = src_dir_value.find(':');
+    if (colon_pos != std::string::npos)
+      src_dir_value.erase(src_dir_value.begin() + colon_pos);
+#else
+    const std::string& src_dir_value = source_dir.value();
+#endif
+    result->value().append(src_dir_value);
+  }
+}
+
 SourceDir GetOutputDirForSourceDir(
     const BuildSettings* build_settings,
     const SourceDir& source_dir,
     const Label& toolchain_label,
     bool is_default_toolchain) {
   return GetOutputDirForSourceDirAsOutputFile(
           build_settings, source_dir, toolchain_label, is_default_toolchain)
       .AsSourceDir(build_settings);
 }
 
 OutputFile GetOutputDirForSourceDirAsOutputFile(
     const BuildSettings* build_settings,
     const SourceDir& source_dir,
     const Label& toolchain_label,
     bool is_default_toolchain) {
   OutputFile result(GetOutputSubdirName(toolchain_label, is_default_toolchain));
   result.value().append("obj/");
 
   if (source_dir.is_source_absolute()) {
     // The source dir is source-absolute, so we trim off the two leading
     // slashes to append to the toolchain object directory.
     result.value().append(&source_dir.value()[2],
                           source_dir.value().size() - 2);
   } else {
     // System-absolute.
-    const std::string& build_dir = build_settings->build_dir().value();
-
-    if (base::StartsWith(source_dir.value(), build_dir,
-                         base::CompareCase::SENSITIVE)) {
-      size_t build_dir_size = build_dir.size();
-      result.value().append(&source_dir.value()[build_dir_size],
-                            source_dir.value().size() - build_dir_size);
-    } else {
-      result.value().append("ABS_PATH");
-#if defined(OS_WIN)
-      // Windows absolute path contains ':' after drive letter. Remove it to
-      // avoid inserting ':' in the middle of path (eg. "ABS_PATH/C:/").
-      std::string src_dir_value = source_dir.value();
-      const auto colon_pos = src_dir_value.find(':');
-      if (colon_pos != std::string::npos)
-        src_dir_value.erase(src_dir_value.begin() + colon_pos);
-#else
-      const std::string& src_dir_value = source_dir.value();
-#endif
-      result.value().append(src_dir_value);
-    }
+    AppendFixedAbsolutePathSuffix(build_settings, source_dir, &result);
   }
   return result;
 }
 
 OutputFile GetOutputDirForSourceDirAsOutputFile(const Settings* settings,
                                                 const SourceDir& source_dir) {
   return GetOutputDirForSourceDirAsOutputFile(
       settings->build_settings(), source_dir,
       settings->toolchain_label(), settings->is_default());
 }
 
 SourceDir GetGenDirForSourceDir(const Settings* settings,
                                 const SourceDir& source_dir) {
   return GetGenDirForSourceDirAsOutputFile(settings, source_dir).AsSourceDir(
       settings->build_settings());
 }
 
 OutputFile GetGenDirForSourceDirAsOutputFile(const Settings* settings,
                                              const SourceDir& source_dir) {
   OutputFile result = GetToolchainGenDirAsOutputFile(settings);
 
   if (source_dir.is_source_absolute()) {
     // The source dir should be source-absolute, so we trim off the two leading
     // slashes to append to the toolchain object directory.
     DCHECK(source_dir.is_source_absolute());
     result.value().append(&source_dir.value()[2],
                           source_dir.value().size() - 2);
+  } else {
+    // System-absolute.
+    AppendFixedAbsolutePathSuffix(settings->build_settings(), source_dir,
+                                  &result);
   }
   return result;
 }
 
 SourceDir GetTargetOutputDir(const Target* target) {
   return GetOutputDirForSourceDirAsOutputFile(
       target->settings(), target->label().dir()).AsSourceDir(
           target->settings()->build_settings());
 }
 
@@ skipping 14 matching lines @@
 
 SourceDir GetCurrentOutputDir(const Scope* scope) {
   return GetOutputDirForSourceDirAsOutputFile(
       scope->settings(), scope->GetSourceDir()).AsSourceDir(
           scope->settings()->build_settings());
 }
 
 SourceDir GetCurrentGenDir(const Scope* scope) {
   return GetGenDirForSourceDir(scope->settings(), scope->GetSourceDir());
 }