Augment the interface of ExternalASTSource::FindExternalLexicalDecls()

to allow clients to specify that they've already (correctly) loaded
declarations, and that no further action is needed. 

Also, make sure that we clear the "has external lexical declarations"
bit before calling FindExternalLexicalDecls(), to avoid infinite
recursion.

llvm-svn: 135306

5 files changed, 23 insertions, 15 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 9b507cfc5e2..4c323da7eee 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2361,8 +2361,15 @@ void RecordDecl::LoadFieldsFromExternalStorage() const {
   ExternalASTSource::Deserializing TheFields(Source);
 
   llvm::SmallVector<Decl*, 64> Decls;
-  if (Source->FindExternalLexicalDeclsBy<FieldDecl>(this, Decls))
+  LoadedFieldsFromExternalStorage = true;  
+  switch (Source->FindExternalLexicalDeclsBy<FieldDecl>(this, Decls)) {
+  case ELR_Success:
+    break;
+    
+  case ELR_AlreadyLoaded:
+  case ELR_Failure:
     return;
+  }
 
 #ifndef NDEBUG
   // Check that all decls we got were FieldDecls.
@@ -2370,8 +2377,6 @@ void RecordDecl::LoadFieldsFromExternalStorage() const {
     assert(isa<FieldDecl>(Decls[i]));
 #endif
 
-  LoadedFieldsFromExternalStorage = true;
-
   if (Decls.empty())
     return;
 
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 7d146572bf6..b2806f092cb 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -839,12 +839,17 @@ DeclContext::LoadLexicalDeclsFromExternalStorage() const {
   // Notify that we have a DeclContext that is initializing.
   ExternalASTSource::Deserializing ADeclContext(Source);
 
+  // Load the external declarations, if any.
   llvm::SmallVector<Decl*, 64> Decls;
-  if (Source->FindExternalLexicalDecls(this, Decls))
-    return;
-
-  // There is no longer any lexical storage in this context
   ExternalLexicalStorage = false;
+  switch (Source->FindExternalLexicalDecls(this, Decls)) {
+  case ELR_Success:
+    break;
+    
+  case ELR_Failure:
+  case ELR_AlreadyLoaded:
+    return;
+  }
 
   if (Decls.empty())
     return;
diff --git a/clang/lib/AST/ExternalASTSource.cpp b/clang/lib/AST/ExternalASTSource.cpp
index f428318a21e..b96d65a729c 100644
--- a/clang/lib/AST/ExternalASTSource.cpp
+++ b/clang/lib/AST/ExternalASTSource.cpp
@@ -51,11 +51,11 @@ ExternalASTSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
 
 void ExternalASTSource::MaterializeVisibleDecls(const DeclContext *DC) { }
 
-bool 
+ExternalLoadResult 
 ExternalASTSource::FindExternalLexicalDecls(const DeclContext *DC,
                                             bool (*isKindWeWant)(Decl::Kind),
                                          llvm::SmallVectorImpl<Decl*> &Result) {
-  return true;
+  return ELR_AlreadyLoaded;
 }
 
 void ExternalASTSource::getMemoryBufferSizes(MemoryBufferSizes &sizes) const { }
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 13933b3eb3f..a4ed5f4da48 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4008,12 +4008,9 @@ Stmt *ASTReader::GetExternalDeclStmt(uint64_t Offset) {
   llvm_unreachable("Broken chain");
 }
 
-bool ASTReader::FindExternalLexicalDecls(const DeclContext *DC,
+ExternalLoadResult ASTReader::FindExternalLexicalDecls(const DeclContext *DC,
                                          bool (*isKindWeWant)(Decl::Kind),
                                          llvm::SmallVectorImpl<Decl*> &Decls) {
-  assert(DC->hasExternalLexicalStorage() &&
-         "DeclContext has no lexical decls in storage");
-
   // There might be lexical decls in multiple parts of the chain, for the TU
   // at least.
   // DeclContextOffsets might reallocate as we load additional decls below,
@@ -4038,7 +4035,7 @@ bool ASTReader::FindExternalLexicalDecls(const DeclContext *DC,
   }
 
   ++NumLexicalDeclContextsRead;
-  return false;
+  return ELR_Success;
 }
 
 DeclContext::lookup_result
diff --git a/clang/lib/Serialization/ChainedIncludesSource.cpp b/clang/lib/Serialization/ChainedIncludesSource.cpp
index da5be957a53..3b7cd23b92a 100644
--- a/clang/lib/Serialization/ChainedIncludesSource.cpp
+++ b/clang/lib/Serialization/ChainedIncludesSource.cpp
@@ -185,7 +185,8 @@ ChainedIncludesSource::FindExternalVisibleDeclsByName(const DeclContext *DC,
 void ChainedIncludesSource::MaterializeVisibleDecls(const DeclContext *DC) {
   return getFinalReader().MaterializeVisibleDecls(DC);
 }
-bool ChainedIncludesSource::FindExternalLexicalDecls(const DeclContext *DC,
+ExternalLoadResult 
+ChainedIncludesSource::FindExternalLexicalDecls(const DeclContext *DC,
                                       bool (*isKindWeWant)(Decl::Kind),
                                       llvm::SmallVectorImpl<Decl*> &Result) {
   return getFinalReader().FindExternalLexicalDecls(DC, isKindWeWant, Result);