From 31ae9737089cd33767e88d64464eed1b2824ba3a Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Wed, 14 Nov 2007 17:46:35 +0000
Subject: [PATCH] SourceManager, IdentifierTable, Selectors are now serialized
 in their own block separate from ASTContext. This block is serialized out
 AFTER writing out ASTContext, but deserialized BEFORE reading in ASTContext.
 This permits the optimization of the serialization of the IdentifierTable
 where we only write out identifiers that are used.

This was needed because TagDecls are owned by Types, and TagDecls contain
identifiers. Thus types need to be written out first to register with the
serializer any identifiers they refer to (and hence need to be serialized out
with IdentifierTable).

llvm-svn: 44125
---
 clang/Driver/SerializationTest.cpp | 38 +++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 11 deletions(-)

diff --git a/clang/Driver/SerializationTest.cpp b/clang/Driver/SerializationTest.cpp
index 075fcba2e08c..b431fb3a154c 100644
--- a/clang/Driver/SerializationTest.cpp
+++ b/clang/Driver/SerializationTest.cpp
@@ -45,7 +45,9 @@ class SerializationTest : public ASTConsumer {
   ASTContext* Context;
   std::list<Decl*> Decls;
   
-  enum { ContextBlock = 0x1, DeclBlock = 0x3 };
+  enum { BasicMetadataBlock,
+         ASTContextBlock,
+         DeclsBlock };
 
 public:  
   SerializationTest() : Context(NULL) {};
@@ -105,7 +107,7 @@ void SerializationTest::Serialize(llvm::sys::Path& Filename) {
   //      Serialize the top-level decls.
   // ===---------------------------------------------------===/  
   
-  Sezr.EnterBlock(DeclBlock);
+  Sezr.EnterBlock(DeclsBlock);
   
   // Create a printer to "consume" our deserialized ASTS.
   ASTConsumer* Printer = CreateASTPrinter();
@@ -125,7 +127,14 @@ void SerializationTest::Serialize(llvm::sys::Path& Filename) {
   //      Serialize the "Translation Unit" metadata.
   // ===---------------------------------------------------===/
 
-  Sezr.EnterBlock(ContextBlock);
+  // Emit ASTContext.
+  Sezr.EnterBlock(ASTContextBlock);  
+  llvm::cerr << "Serializing: ASTContext.\n";  
+  Sezr.EmitOwnedPtr(Context);  
+  Sezr.ExitBlock();  
+  
+  
+  Sezr.EnterBlock(BasicMetadataBlock);
 
   // "Fake" emit the SourceManager.
   llvm::cerr << "Faux-serializing: SourceManager.\n";
@@ -142,11 +151,7 @@ void SerializationTest::Serialize(llvm::sys::Path& Filename) {
   // Emit the Identifier Table.
   llvm::cerr << "Serializing: IdentifierTable.\n";  
   Sezr.EmitOwnedPtr(&Context->Idents);
-  
-  // Emit the ASTContext.
-  llvm::cerr << "Serializing: ASTContext.\n";  
-  Sezr.EmitOwnedPtr(Context);
-  
+
   Sezr.ExitBlock();  
   
   // ===---------------------------------------------------===/
@@ -207,8 +212,16 @@ void SerializationTest::Deserialize(llvm::sys::Path& Filename) {
   //      Deserialize the "Translation Unit" metadata.
   // ===---------------------------------------------------===/
   
-  // Skip to the block that has the SourceManager, etc.
-  bool FoundBlock = Dezr.SkipToBlock(ContextBlock);
+  // Skip to the BasicMetaDataBlock.  First jump to ASTContextBlock
+  // (which will appear earlier) and record its location.
+  
+  bool FoundBlock = Dezr.SkipToBlock(ASTContextBlock);
+  assert (FoundBlock);
+
+  llvm::Deserializer::Location ASTContextBlockLoc =
+    Dezr.getCurrentBlockLocation();
+  
+  FoundBlock = Dezr.SkipToBlock(BasicMetadataBlock);
   assert (FoundBlock);
   
   // "Fake" read the SourceManager.
@@ -227,6 +240,9 @@ void SerializationTest::Deserialize(llvm::sys::Path& Filename) {
   llvm::cerr << "Deserializing: IdentifierTable\n";
   Dezr.ReadOwnedPtr<IdentifierTable>();
   
+  // Now jump back to ASTContextBlock and read the ASTContext.
+  Dezr.JumpTo(ASTContextBlockLoc);
+  
   // Read the ASTContext.  
   llvm::cerr << "Deserializing: ASTContext.\n";
   Dezr.ReadOwnedPtr<ASTContext>();
@@ -237,7 +253,7 @@ void SerializationTest::Deserialize(llvm::sys::Path& Filename) {
   
   // "Rewind" the stream.  Find the block with the serialized top-level decls.
   Dezr.Rewind();
-  FoundBlock = Dezr.SkipToBlock(DeclBlock);
+  FoundBlock = Dezr.SkipToBlock(DeclsBlock);
   assert (FoundBlock);
   llvm::Deserializer::Location DeclBlockLoc = Dezr.getCurrentBlockLocation();