Windows precompiled header support in GN

tools/gn/ninja_binary_target_writer.h

 // 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.
 
 #ifndef TOOLS_GN_NINJA_BINARY_TARGET_WRITER_H_
 #define TOOLS_GN_NINJA_BINARY_TARGET_WRITER_H_
 
 #include "base/macros.h"
 #include "tools/gn/config_values.h"
 #include "tools/gn/ninja_target_writer.h"
 #include "tools/gn/toolchain.h"
 #include "tools/gn/unique_vector.h"
 
 struct EscapeOptions;
+class SourceFileTypeSet;
 
 // Writes a .ninja file for a binary target type (an executable, a shared
 // library, or a static library).
 class NinjaBinaryTargetWriter : public NinjaTargetWriter {
  public:
   NinjaBinaryTargetWriter(const Target* target, std::ostream& out);
   ~NinjaBinaryTargetWriter() override;
 
   void Run() override;
 
  private:
   typedef std::set<OutputFile> OutputFileSet;
+  class SourceFileTypeSet;
 
-  void WriteCompilerVars();
-  void WriteSources(std::vector<OutputFile>* object_files,
+  // Writes all flags for the compiler: includes, defines, cflags, etc.
+  // Any .pch files this function generates references to will be appended to
+  // the *pch_files vector.
+  void WriteCompilerVars(const SourceFileTypeSet& used_types);
+  void WriteOneFlag(
+      SubstitutionType subst_enum,
+      const std::vector<std::string>& (ConfigValues::* getter)() const,
+      EscapeOptions flag_escape_options);
+
+  void WritePrecompiledHeaderCommands(const SourceFileTypeSet& used_types,
+                                      const OutputFile& input_dep,
+                                      std::vector<OutputFile>* object_files);
+  void WritePrecompiledHeaderCommand(SubstitutionType flag_type,
+                                     Toolchain::ToolType tool_type,
+                                     const OutputFile& input_dep,
+                                     std::vector<OutputFile>* object_files);
+
+  // extra_deps are additional dependencies to run before the rule.
+  //
+  // iorder_only_dep is the name of the stamp file that covers the dependencies
+  // that must be run before doing any compiles.
+  //
+  // The files produced by the compiler will be added to two output vectors.
+  void WriteSources(const std::vector<OutputFile>& extra_deps,
+                    const OutputFile& order_only_dep,
+                    std::vector<OutputFile>* object_files,
                     std::vector<SourceFile>* other_files);
+
+  // Writes a build line.
+  void WriteCompilerBuildLine(const SourceFile& source,
+                              const std::vector<OutputFile>& extra_deps,
+                              const OutputFile& order_only_dep,
+                              Toolchain::ToolType tool_type,
+                              const std::vector<OutputFile>& outputs);
+
   void WriteLinkerStuff(const std::vector<OutputFile>& object_files,
                         const std::vector<SourceFile>& other_files);
   void WriteLinkerFlags(const SourceFile* optional_def_file);
   void WriteLibs();
   void WriteOutputExtension();
   void WriteSolibs(const std::vector<OutputFile>& solibs);
 
   // Writes the stamp line for a source set. These are not linked.
   void WriteSourceSetStamp(const std::vector<OutputFile>& object_files);
 
@@ skipping 30 matching lines @@
   // this class is currently writing.
   //
   // The function can succeed with a "NONE" tool type for object files which are
   // just passed to the output. The output will always be overwritten, not
   // appended to.
   bool GetOutputFilesForSource(const Target* target,
                                const SourceFile& source,
                                Toolchain::ToolType* computed_tool_type,
                                std::vector<OutputFile>* outputs) const;
 
+  // Appends the object files generated by the given source set to the given
+  // output vector.
+  void AddSourceSetObjectFiles(const Target* source_set,
+                               UniqueVector<OutputFile>* obj_files) const;
+
+  // Returns the object files for the precompiled header of the given type
+  // (flag type and tool type must match). The given target is used rather than
+  // this class' target_ so any target's object files can be retrieved.
+  void GetWindowsPCHObjectFiles(const Target* target,
+                                SubstitutionType flag_type,
+                                Toolchain::ToolType tool_type,
+                                std::vector<OutputFile>* outputs) const;
+
+  // Returns the computed name of the Windows .pch file for the given
+  // flag type (C/C++/ObjC/ObjC++).
+  OutputFile GetWindowsPCHFile(SubstitutionType flag_type) const;
+
   const Tool* tool_;
 
+  // Cached version of the prefix used for rule types for this toolchain.
+  std::string rule_prefix_;
+
   DISALLOW_COPY_AND_ASSIGN(NinjaBinaryTargetWriter);
 };
 
 #endif  // TOOLS_GN_NINJA_BINARY_TARGET_WRITER_H_