Some preparatory work for chained PCH. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107915 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 19 insertions, 5 deletions

diff --git a/include/clang/Frontend/ASTConsumers.h b/include/clang/Frontend/ASTConsumers.h
index e42b1f2cd9..5718979ba1 100644
--- a/include/clang/Frontend/ASTConsumers.h
+++ b/include/clang/Frontend/ASTConsumers.h
@@ -29,6 +29,7 @@ class CodeGenOptions;
 class Diagnostic;
 class FileManager;
 class LangOptions;
+class PCHReader;
 class Preprocessor;
 class TargetOptions;
 
@@ -62,6 +63,7 @@ ASTConsumer *CreateDeclContextPrinter();
 // times.
 ASTConsumer *CreatePCHGenerator(const Preprocessor &PP,
                                 llvm::raw_ostream *OS,
+                                const PCHReader *Chain,
                                 const char *isysroot = 0);
 
 // Inheritance viewer: for C++ code, creates a graph of the inheritance
diff --git a/include/clang/Frontend/CompilerInstance.h b/include/clang/Frontend/CompilerInstance.h
index 06dc8004a6..54ce8bfe3b 100644
--- a/include/clang/Frontend/CompilerInstance.h
+++ b/include/clang/Frontend/CompilerInstance.h
@@ -34,6 +34,7 @@ class DiagnosticClient;
 class ExternalASTSource;
 class FileManager;
 class FrontendAction;
+class PCHReader;
 class Preprocessor;
 class SourceManager;
 class TargetInfo;
@@ -96,6 +97,9 @@ class CompilerInstance {
   /// The list of active output files.
   std::list< std::pair<std::string, llvm::raw_ostream*> > OutputFiles;
 
+  /// The PCH reader. Not owned; the ASTContext owns this.
+  PCHReader *Reader;
+
   void operator=(const CompilerInstance &);  // DO NOT IMPLEMENT
   CompilerInstance(const CompilerInstance&); // DO NOT IMPLEMENT
 public:
@@ -507,6 +511,9 @@ public:
   createPCHExternalASTSource(llvm::StringRef Path, const std::string &Sysroot,
                              Preprocessor &PP, ASTContext &Context);
 
+  /// Get the PCH reader, if any.
+  PCHReader *getPCHReader() { return Reader; }
+
   /// Create a code completion consumer using the invocation; note that this
   /// will cause the source manager to truncate the input source file at the
   /// completion point.
diff --git a/include/clang/Frontend/PCHBitCodes.h b/include/clang/Frontend/PCHBitCodes.h
index 4da96044c5..afa6d93ef2 100644
--- a/include/clang/Frontend/PCHBitCodes.h
+++ b/include/clang/Frontend/PCHBitCodes.h
@@ -30,10 +30,10 @@ namespace clang {
     /// designed for the previous version could not support reading
     /// the new version), this number should be increased.
     ///
-    /// Version 3 of PCH files also requires that the version control branch and
+    /// Version 4 of PCH files also requires that the version control branch and
     /// revision match exactly, since there is no backward compatibility of
     /// PCH files at this time.
-    const unsigned VERSION_MAJOR = 3;
+    const unsigned VERSION_MAJOR = 4;
 
     /// \brief PCH minor version number supported by this version of
     /// Clang.
@@ -47,7 +47,7 @@ namespace clang {
 
     /// \brief An ID number that refers to a declaration in a PCH file.
     ///
-    /// The ID numbers of types are consecutive (in order of
+    /// The ID numbers of declarations are consecutive (in order of
     /// discovery) and start at 2. 0 is reserved for NULL, and 1 is
     /// reserved for the translation unit declaration.
     typedef uint32_t DeclID;
@@ -232,7 +232,11 @@ namespace clang {
       VTABLE_USES = 24,
 
       /// \brief Record code for the array of dynamic classes.
-      DYNAMIC_CLASSES = 25
+      DYNAMIC_CLASSES = 25,
+
+      /// \brief Record code for the chained PCH metadata, including the
+      /// PCH version and the name of the PCH this is chained to.
+      CHAINED_METADATA = 26
 
     };
 
diff --git a/include/clang/Frontend/PCHWriter.h b/include/clang/Frontend/PCHWriter.h
index 1e1ce51e4a..0b0c866bd6 100644
--- a/include/clang/Frontend/PCHWriter.h
+++ b/include/clang/Frontend/PCHWriter.h
@@ -39,6 +39,7 @@ class CXXBaseOrMemberInitializer;
 class LabelStmt;
 class MacroDefinition;
 class MemorizeStatCalls;
+class PCHReader;
 class Preprocessor;
 class Sema;
 class SourceManager;
@@ -257,7 +258,7 @@ public:
   /// \param PPRec Record of the preprocessing actions that occurred while
   /// preprocessing this file, e.g., macro instantiations
   void WritePCH(Sema &SemaRef, MemorizeStatCalls *StatCalls,
-                const char* isysroot);
+                const PCHReader *Chain, const char* isysroot);
 
   /// \brief Emit a source location.
   void AddSourceLocation(SourceLocation Loc, RecordData &Record);