Make the deserialization of macro definitions lazy, so that we can
load identifiers without loading their corresponding macro
definitions. This is likely to improve PCH performance slightly, and
reduces deserialization stack depth considerably when using
preprocessor metaprogramming.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117750 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index aa76765..22d3cbc 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -682,7 +682,7 @@
// definition.
if (hasMacroDefinition) {
uint32_t Offset = ReadUnalignedLE32(d);
- Reader.ReadMacroRecord(F, Offset);
+ Reader.SetIdentifierIsMacro(II, F, Offset);
DataLen -= 4;
}
@@ -1568,6 +1568,22 @@
}
}
+void ASTReader::SetIdentifierIsMacro(IdentifierInfo *II, PerFileData &F,
+ uint64_t Offset) {
+ // Note that this identifier has a macro definition.
+ II->setHasMacroDefinition(true);
+
+ // Adjust the offset based on our position in the chain.
+ for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
+ if (Chain[I] == &F)
+ break;
+
+ Offset += Chain[I]->SizeInBits;
+ }
+
+ UnreadMacroRecordOffsets[II] = Offset;
+}
+
void ASTReader::ReadDefinedMacros() {
for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
PerFileData &F = *Chain[N - I - 1];
@@ -1629,6 +1645,39 @@
}
}
}
+
+ // Drain the unread macro-record offsets map.
+ while (!UnreadMacroRecordOffsets.empty())
+ LoadMacroDefinition(UnreadMacroRecordOffsets.begin());
+}
+
+void ASTReader::LoadMacroDefinition(
+ llvm::DenseMap<IdentifierInfo *, uint64_t>::iterator Pos) {
+ assert(Pos != UnreadMacroRecordOffsets.end() && "Unknown macro definition");
+ PerFileData *F = 0;
+ uint64_t Offset = Pos->second;
+ UnreadMacroRecordOffsets.erase(Pos);
+
+ for (unsigned I = 0, N = Chain.size(); I != N; ++I) {
+ if (Offset < Chain[I]->SizeInBits) {
+ F = Chain[I];
+ break;
+ }
+
+ Offset -= Chain[I]->SizeInBits;
+ }
+ if (!F) {
+ Error("Malformed macro record offset");
+ return;
+ }
+
+ ReadMacroRecord(*F, Offset);
+}
+
+void ASTReader::LoadMacroDefinition(IdentifierInfo *II) {
+ llvm::DenseMap<IdentifierInfo *, uint64_t>::iterator Pos
+ = UnreadMacroRecordOffsets.find(II);
+ LoadMacroDefinition(Pos);
}
MacroDefinition *ASTReader::getMacroDefinition(MacroID ID) {