Debug Info: Add basic support for external types references.
This is a necessary prerequisite for bootstrapping the emission
of debug info inside modules.
- Adds a FlagExternalTypeRef to DICompositeType.
External types must have a unique identifier.
- External type references are emitted using a forward declaration
with a DW_AT_signature([DW_FORM_ref_sig8]) based on the UID.
http://reviews.llvm.org/D9612
llvm-svn: 242302
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 7d03a39..4587566 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -467,7 +467,10 @@
for (auto *Ty : CUNode->getRetainedTypes()) {
// The retained types array by design contains pointers to
// MDNodes rather than DIRefs. Unique them here.
- CU.getOrCreateTypeDIE(cast<DIType>(resolve(Ty->getRef())));
+ DIType *RT = cast<DIType>(resolve(Ty->getRef()));
+ if (!RT->isExternalTypeRef())
+ // There is no point in force-emitting a forward declaration.
+ CU.getOrCreateTypeDIE(RT);
}
// Emit imported_modules last so that the relevant context is already
// available.
@@ -1884,7 +1887,7 @@
return &SplitTypeUnitFileTable;
}
-static uint64_t makeTypeSignature(StringRef Identifier) {
+uint64_t DwarfDebug::makeTypeSignature(StringRef Identifier) {
MD5 Hash;
Hash.update(Identifier);
// ... take the least significant 8 bytes and return those. Our MD5