Revert "Debug Info: Add basic support for external types references."

This reverts commit r242302. External type refs of this form were
never used by any LLVM frontend so this is effectively dead code.
(They were introduced to support clang module debug info, but in the
end we came up with a better design that doesn't use this feature at
all.)

rdar://problem/25897929

Differential Revision: https://reviews.llvm.org/D30917

llvm-svn: 297684

3 files changed, 1 insertions, 20 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index c4a5a58df5d..416f3afc070 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -544,7 +544,6 @@ void DwarfDebug::beginModule() {
       // The retained types array by design contains pointers to
       // MDNodes rather than DIRefs. Unique them here.
       if (DIType *RT = dyn_cast<DIType>(Ty))
-        if (!RT->isExternalTypeRef())
           // There is no point in force-emitting a forward declaration.
           CU.getOrCreateTypeDIE(RT);
     }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index fa74c9043a9..a7be770df63 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -297,13 +297,6 @@ void DwarfUnit::addDIETypeSignature(DIE &Die, uint64_t Signature) {
                dwarf::DW_FORM_ref_sig8, DIEInteger(Signature));
 }
 
-void DwarfUnit::addDIETypeSignature(DIE &Die, dwarf::Attribute Attribute,
-                                    StringRef Identifier) {
-  uint64_t Signature = DD->makeTypeSignature(Identifier);
-  Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_ref_sig8,
-               DIEInteger(Signature));
-}
-
 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute,
                             DIEEntry Entry) {
   const DIEUnit *CU = Die.getUnit();
@@ -696,8 +689,7 @@ DIE *DwarfTypeUnit::createTypeDIE(const DICompositeType *Ty) {
 
   constructTypeDIE(TyDIE, cast<DICompositeType>(Ty));
 
-  if (!Ty->isExternalTypeRef())
-    updateAcceleratorTables(Context, Ty, TyDIE);
+  updateAcceleratorTables(Context, Ty, TyDIE);
   return &TyDIE;
 }
 
@@ -911,13 +903,6 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy) {
 }
 
 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
-  if (CTy->isExternalTypeRef()) {
-    StringRef Identifier = CTy->getIdentifier();
-    assert(!Identifier.empty() && "external type ref without identifier");
-    addFlag(Buffer, dwarf::DW_AT_declaration);
-    return addDIETypeSignature(Buffer, dwarf::DW_AT_signature, Identifier);
-  }
-
   // Add name if not anonymous or intermediate type.
   StringRef Name = CTy->getName();
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
index a48b976a6fa..d626ef920f9 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -198,9 +198,6 @@ public:
 
   /// Add a type's DW_AT_signature and set the  declaration flag.
   void addDIETypeSignature(DIE &Die, uint64_t Signature);
-  /// Add an attribute containing the type signature for a unique identifier.
-  void addDIETypeSignature(DIE &Die, dwarf::Attribute Attribute,
-                           StringRef Identifier);
 
   /// Add block data.
   void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Block);