Lazy deserialization of function bodies for PCH files. For the Carbon
"Hello, World!", this takes us from deserializing 6469
statements/expressions down to deserializing 1
statement/expression. It only translated into a 1% improvement on the
Carbon-prefixed 403.gcc, but (a) it's the right thing to do, and (b)
we expect this to matter more once we lazily deserialize identifiers.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69407 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index 5ea1f7c..dc8d3fc 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -140,7 +140,7 @@
void PCHDeclReader::VisitFunctionDecl(FunctionDecl *FD) {
VisitValueDecl(FD);
if (Record[Idx++])
- FD->setBody(cast<CompoundStmt>(Reader.ReadStmt()));
+ FD->setLazyBody(Reader.getStream().GetCurrentBitNo());
FD->setPreviousDeclaration(
cast_or_null<FunctionDecl>(Reader.GetDecl(Record[Idx++])));
FD->setStorageClass((FunctionDecl::StorageClass)Record[Idx++]);
@@ -1880,6 +1880,15 @@
return ReadDeclRecord(DeclOffsets[Index], Index);
}
+Stmt *PCHReader::GetStmt(uint64_t Offset) {
+ // Keep track of where we are in the stream, then jump back there
+ // after reading this declaration.
+ SavedStreamPosition SavedPosition(Stream);
+
+ Stream.JumpToBit(Offset);
+ return ReadStmt();
+}
+
bool PCHReader::ReadDeclsLexicallyInContext(DeclContext *DC,
llvm::SmallVectorImpl<pch::DeclID> &Decls) {
assert(DC->hasExternalLexicalStorage() &&