Introduce a new data structure, LazyVector, which is a vector whose

contents are lazily loaded on demand from an external source (e.g., an
ExternalASTSource or ExternalSemaSource). The "loaded" entities are
kept separate from the "local" entities, so that the two can grow
independently.

Switch Sema::TentativeDefinitions from a normal vector that is eagerly
populated by the ASTReader into one of these LazyVectors, making the
ASTReader a bit more like me (i.e., lazy).

llvm-svn: 136262

1 files changed, 12 insertions, 7 deletions

diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 14824a0810f..1acc140acdd 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -2805,10 +2805,13 @@ void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   // TentativeDefinitions order.  Generally, this record will be empty for
   // headers.
   RecordData TentativeDefinitions;
-  for (unsigned i = 0, e = SemaRef.TentativeDefinitions.size(); i != e; ++i) {
-    AddDeclRef(SemaRef.TentativeDefinitions[i], TentativeDefinitions);
+  for (Sema::TentativeDefinitionsType::iterator 
+            T = SemaRef.TentativeDefinitions.begin(0, true),
+         TEnd = SemaRef.TentativeDefinitions.end();
+       T != TEnd; ++T) {
+    AddDeclRef(*T, TentativeDefinitions);
   }
-
+  
   // Build a record containing all of the file scoped decls in this file.
   RecordData UnusedFileScopedDecls;
   for (unsigned i=0, e = SemaRef.UnusedFileScopedDecls.size(); i !=e; ++i)
@@ -3072,11 +3075,13 @@ void ASTWriter::WriteASTChain(Sema &SemaRef, MemorizeStatCalls *StatCalls,
   // Build a record containing all of the new tentative definitions in this
   // file, in TentativeDefinitions order.
   RecordData TentativeDefinitions;
-  for (unsigned i = 0, e = SemaRef.TentativeDefinitions.size(); i != e; ++i) {
-    if (SemaRef.TentativeDefinitions[i]->getPCHLevel() == 0)
-      AddDeclRef(SemaRef.TentativeDefinitions[i], TentativeDefinitions);
+  for (Sema::TentativeDefinitionsType::iterator 
+       T = SemaRef.TentativeDefinitions.begin(0, true),
+       TEnd = SemaRef.TentativeDefinitions.end();
+       T != TEnd; ++T) {
+    AddDeclRef(*T, TentativeDefinitions);
   }
-
+  
   // Build a record containing all of the file scoped decls in this file.
   RecordData UnusedFileScopedDecls;
   for (unsigned i=0, e = SemaRef.UnusedFileScopedDecls.size(); i !=e; ++i) {