From: Douglas Gregor <dgregor@apple.com>
Date: Tue, 24 Jan 2012 15:24:38 +0000 (+0000)
Subject: Only mark an IdentifierInfo as having changed since deserialization
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5d5051f3e79bf754134ccdf7a1dc7778cd80c73e;p=clang

Only mark an IdentifierInfo as having changed since deserialization
when it actually has changed (and not, e.g., when we've simply attached a
deserialized macro definition). Good for ~1.5% reduction in module
file size, mostly in the identifier table.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148808 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index c6190b0470..33efbd960c 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -433,7 +433,8 @@ public:
 
   /// setMacroInfo - Specify a macro for this identifier.
   ///
-  void setMacroInfo(IdentifierInfo *II, MacroInfo *MI);
+  void setMacroInfo(IdentifierInfo *II, MacroInfo *MI,
+                    bool LoadedFromAST = false);
 
   /// macro_iterator/macro_begin/macro_end - This allows you to walk the current
   /// state of the macro table.  This visits every currently-defined macro.
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 73efb4d576..035272279d 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -47,16 +47,17 @@ MacroInfo *Preprocessor::getInfoForMacro(IdentifierInfo *II) const {
 
 /// setMacroInfo - Specify a macro for this identifier.
 ///
-void Preprocessor::setMacroInfo(IdentifierInfo *II, MacroInfo *MI) {
+void Preprocessor::setMacroInfo(IdentifierInfo *II, MacroInfo *MI,
+                                bool LoadedFromAST) {
   if (MI) {
     Macros[II] = MI;
     II->setHasMacroDefinition(true);
-    if (II->isFromAST())
+    if (II->isFromAST() && !LoadedFromAST)
       II->setChangedSinceDeserialization();
   } else if (II->hasMacroDefinition()) {
     Macros.erase(II);
     II->setHasMacroDefinition(false);
-    if (II->isFromAST())
+    if (II->isFromAST() && !LoadedFromAST)
       II->setChangedSinceDeserialization();
   }
 }
diff --git a/lib/Sema/IdentifierResolver.cpp b/lib/Sema/IdentifierResolver.cpp
index a80f23f58e..b4691617d0 100644
--- a/lib/Sema/IdentifierResolver.cpp
+++ b/lib/Sema/IdentifierResolver.cpp
@@ -202,10 +202,6 @@ void IdentifierResolver::InsertDeclAfter(iterator Pos, NamedDecl *D) {
     return;
   }
 
-  if (IdentifierInfo *II = Name.getAsIdentifierInfo())
-    if (II->isFromAST())
-      II->setChangedSinceDeserialization();
-  
   // General case: insert the declaration at the appropriate point in the 
   // list, which already has at least two elements.
   IdDeclInfo *IDI = toIdDeclInfo(Ptr);
@@ -323,7 +319,7 @@ static DeclMatchKind compareDeclarations(NamedDecl *Existing, NamedDecl *New) {
 
 bool IdentifierResolver::tryAddTopLevelDecl(NamedDecl *D, DeclarationName Name){
   if (IdentifierInfo *II = Name.getAsIdentifierInfo())
-    updatingIdentifier(*II);
+    readingIdentifier(*II);
   
   void *Ptr = Name.getFETokenInfo<void>();
     
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 5842bbb468..683bc379cb 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -510,8 +510,10 @@ IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
     // For uninteresting identifiers, just build the IdentifierInfo
     // and associate it with the persistent ID.
     IdentifierInfo *II = KnownII;
-    if (!II)
+    if (!II) {
       II = &Reader.getIdentifierTable().getOwn(StringRef(k.first, k.second));
+      KnownII = II;
+    }
     Reader.SetIdentifierInfo(ID, II);
     II->setIsFromAST();
     Reader.markIdentifierUpToDate(II);    
@@ -538,8 +540,10 @@ IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
   // Build the IdentifierInfo itself and link the identifier ID with
   // the new IdentifierInfo.
   IdentifierInfo *II = KnownII;
-  if (!II)
+  if (!II) {
     II = &Reader.getIdentifierTable().getOwn(StringRef(k.first, k.second));
+    KnownII = II;
+  }
   Reader.markIdentifierUpToDate(II);
   II->setIsFromAST();
 
@@ -1362,7 +1366,7 @@ void ASTReader::ReadMacroRecord(ModuleFile &F, uint64_t Offset) {
       }
 
       // Finally, install the macro.
-      PP.setMacroInfo(II, MI);
+      PP.setMacroInfo(II, MI, /*LoadedFromAST=*/true);
 
       // Remember that we saw this macro last so that we add the tokens that
       // form its body to it.
@@ -1541,7 +1545,7 @@ void ASTReader::ReadDefinedMacros() {
 }
 
 void ASTReader::LoadMacroDefinition(
-                     llvm::DenseMap<IdentifierInfo *, uint64_t>::iterator Pos) {
+                    llvm::DenseMap<IdentifierInfo *, uint64_t>::iterator Pos) {
   assert(Pos != UnreadMacroRecordOffsets.end() && "Unknown macro definition");
   uint64_t Offset = Pos->second;
   UnreadMacroRecordOffsets.erase(Pos);
@@ -1579,9 +1583,12 @@ namespace {
       if (!IdTable)
         return false;
       
+      ASTIdentifierLookupTrait Trait(IdTable->getInfoObj().getReader(),
+                                     M, This->Found);
+                                     
       std::pair<const char*, unsigned> Key(This->Name.begin(), 
                                            This->Name.size());
-      ASTIdentifierLookupTable::iterator Pos = IdTable->find(Key);
+      ASTIdentifierLookupTable::iterator Pos = IdTable->find(Key, &Trait);
       if (Pos == IdTable->end())
         return false;
       
diff --git a/lib/Serialization/ASTReaderInternals.h b/lib/Serialization/ASTReaderInternals.h
index 635f95fe59..3a1dfcf4b7 100644
--- a/lib/Serialization/ASTReaderInternals.h
+++ b/lib/Serialization/ASTReaderInternals.h
@@ -129,6 +129,9 @@ public:
   IdentifierInfo *ReadData(const internal_key_type& k,
                            const unsigned char* d,
                            unsigned DataLen);
+  
+  ASTReader &getReader() const { return Reader; }
+  
 };
   
 /// \brief The on-disk hash table used to contain information about