[cfe-commits] r125324 - in /cfe/trunk: include/clang/Serialization/ASTWriter.h lib/Serialization/ASTWriter.cpp test/PCH/reinclude1.h

[Douglas Gregor]

Author: dgregor
Date: Thu Feb 10 18:26:14 2011
New Revision: 125324

URL: http://llvm.org/viewvc/llvm-project?rev=125324&view=rev
Log:
Implement AST/PCH chaining support for macro definitions. Previously,
we would deserialize all of the macro definitions we knew about while
serializing the macro definitions at the end of the AST/PCH file. Even
though we skipped most of them (since they were unchanged), it's still
a performance problem.

Now, we do the standard AST/PCH chaining trick: watch what identifiers
are deserialized as macro names, and consider only those identifiers
(along with macro definitions that have been deserialized/written in
the source) when serializing the preprocessor state.


Modified:
    cfe/trunk/include/clang/Serialization/ASTWriter.h
    cfe/trunk/lib/Serialization/ASTWriter.cpp
    cfe/trunk/test/PCH/reinclude1.h

Modified: cfe/trunk/include/clang/Serialization/ASTWriter.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Serialization/ASTWriter.h?rev=125324&r1=125323&r2=125324&view=diff
==============================================================================
--- cfe/trunk/include/clang/Serialization/ASTWriter.h (original)
+++ cfe/trunk/include/clang/Serialization/ASTWriter.h Thu Feb 10 18:26:14 2011
@@ -184,6 +184,9 @@
   /// defined.
   llvm::DenseMap<const IdentifierInfo *, uint64_t> MacroOffsets;
 
+  /// \brief The set of identifiers that had macro definitions at some point.
+  std::vector<const IdentifierInfo *> DeserializedMacroNames;
+                    
   /// \brief The first ID number we can use for our own macro definitions.
   serialization::MacroID FirstMacroID;
   

Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=125324&r1=125323&r2=125324&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTWriter.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTWriter.cpp Thu Feb 10 18:26:14 2011
@@ -1536,7 +1536,8 @@
   llvm::SmallVector<std::pair<const IdentifierInfo *, MacroInfo *>, 2> 
     MacrosToEmit;
   llvm::SmallPtrSet<const IdentifierInfo*, 4> MacroDefinitionsSeen;
-  for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
+  for (Preprocessor::macro_iterator I = PP.macro_begin(Chain == 0), 
+                                    E = PP.macro_end(Chain == 0);
        I != E; ++I) {
     MacroDefinitionsSeen.insert(I->first);
     MacrosToEmit.push_back(std::make_pair(I->first, I->second));
@@ -1547,10 +1548,21 @@
   llvm::array_pod_sort(MacrosToEmit.begin(), MacrosToEmit.end(), 
                        &compareMacroDefinitions);
   
+  // Resolve any identifiers that defined macros at the time they were
+  // deserialized, adding them to the list of macros to emit (if appropriate).
+  for (unsigned I = 0, N = DeserializedMacroNames.size(); I != N; ++I) {
+    IdentifierInfo *Name
+      = const_cast<IdentifierInfo *>(DeserializedMacroNames[I]);
+    if (Name->hasMacroDefinition() && MacroDefinitionsSeen.insert(Name))
+      MacrosToEmit.push_back(std::make_pair(Name, PP.getMacroInfo(Name)));
+  }
+  
   for (unsigned I = 0, N = MacrosToEmit.size(); I != N; ++I) {
     const IdentifierInfo *Name = MacrosToEmit[I].first;
     MacroInfo *MI = MacrosToEmit[I].second;
-
+    if (!MI)
+      continue;
+    
     // Don't emit builtin macros like __LINE__ to the AST file unless they have
     // been redefined by the header (in which case they are not isBuiltinMacro).
     // Also skip macros from a AST file if we're chaining.
@@ -1603,7 +1615,6 @@
       // FIXME: When reading literal tokens, reconstruct the literal pointer if
       // it is needed.
       AddIdentifierRef(Tok.getIdentifierInfo(), Record);
-
       // FIXME: Should translate token kind to a stable encoding.
       Record.push_back(Tok.getKind());
       // FIXME: Should translate token flags to a stable encoding.
@@ -3681,6 +3692,8 @@
 
 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
   IdentifierIDs[II] = ID;
+  if (II->hasMacroDefinition())
+    DeserializedMacroNames.push_back(II);
 }
 
 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {

Modified: cfe/trunk/test/PCH/reinclude1.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/PCH/reinclude1.h?rev=125324&r1=125323&r2=125324&view=diff
==============================================================================
--- cfe/trunk/test/PCH/reinclude1.h (original)
+++ cfe/trunk/test/PCH/reinclude1.h Thu Feb 10 18:26:14 2011
@@ -2,3 +2,6 @@
   int x;
   int y;
 }
+
+int foo;
+#define foo foo