Debug Info: Use DIScopeRef for DIType::getContext.

    
In DIBuilder, the context field of a TAG_member is updated to use the
scope reference. Verifier is updated accordingly.
    
DebugInfoFinder now needs to generate a type identifier map to have
access to the actual scope. Same applies for BreakpointPrinter.
    
processModule of DebugInfoFinder is called during initialization phase
of the verifier to make sure the type identifier map is constructed early
enough.
    
We are now able to unique a simple class as demonstrated by the added
testing case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190334 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 20 insertions, 12 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index f9ce591833..1a527f24fc 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -800,7 +800,7 @@ DIE *CompileUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
     addAccelType(Ty.getName(), std::make_pair(TyDIE, Flags));
   }
 
-  addToContextOwner(TyDIE, Ty.getContext());
+  addToContextOwner(TyDIE, DD->resolve(Ty.getContext()));
   return TyDIE;
 }
 
@@ -832,7 +832,7 @@ void CompileUnit::addType(DIE *Entity, DIType Ty, uint16_t Attribute) {
 /// addGlobalType - Add a new global type to the compile unit.
 ///
 void CompileUnit::addGlobalType(DIType Ty) {
-  DIDescriptor Context = Ty.getContext();
+  DIDescriptor Context = DD->resolve(Ty.getContext());
   if (Ty.isCompositeType() && !Ty.getName().empty() && !Ty.isForwardDecl()
       && (!Context || Context.isCompileUnit() || Context.isFile()
           || Context.isNameSpace()))
@@ -914,7 +914,7 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DIDerivedType DTy) {
 /// Return true if the type is appropriately scoped to be contained inside
 /// its own type unit.
 static bool isTypeUnitScoped(DIType Ty, const DwarfDebug *DD) {
-  DIScope Parent = Ty.getContext();
+  DIScope Parent = DD->resolve(Ty.getContext());
   while (Parent) {
     // Don't generate a hash for anything scoped inside a function.
     if (Parent.isSubprogram())
@@ -1088,7 +1088,7 @@ void CompileUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
       addDIEEntry(&Buffer, dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4,
                   getOrCreateTypeDIE(DIType(ContainingType)));
     else
-      addToContextOwner(&Buffer, CTy.getContext());
+      addToContextOwner(&Buffer, DD->resolve(CTy.getContext()));
 
     if (CTy.isObjcClassComplete())
       addFlag(&Buffer, dwarf::DW_AT_APPLE_objc_complete_type);
@@ -1373,7 +1373,7 @@ void CompileUnit::createGlobalVariableDIE(const MDNode *N) {
     // We need the declaration DIE that is in the static member's class.
     // But that class might not exist in the DWARF yet.
     // Creating the class will create the static member decl DIE.
-    getOrCreateContextDIE(SDMDecl.getContext());
+    getOrCreateContextDIE(DD->resolve(SDMDecl.getContext()));
     VariableDIE = getDIE(SDMDecl);
     assert(VariableDIE && "Static member decl has no context?");
     IsStaticMember = true;
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 1cfadc91e0..21f997ea48 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -341,7 +341,7 @@ bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
   if (D.isSubprogram())
     return true;
   if (D.isType())
-    return isSubprogramContext(DIType(Context).getContext());
+    return isSubprogramContext(resolve(DIType(Context).getContext()));
   return false;
 }
 
@@ -2656,7 +2656,7 @@ DIScope DwarfDebug::resolve(DIScopeRef SRef) const {
 DIScope DwarfDebug::getScopeContext(DIScope S) const {
 
   if (S.isType())
-    return DIType(S).getContext();
+    return resolve(DIType(S).getContext());
 
   if (S.isSubprogram())
     return DISubprogram(S).getContext();
diff --git a/lib/IR/DIBuilder.cpp b/lib/IR/DIBuilder.cpp
index c485cc15ec..9439305857 100644
--- a/lib/IR/DIBuilder.cpp
+++ b/lib/IR/DIBuilder.cpp
@@ -417,7 +417,7 @@ DIDerivedType DIBuilder::createMemberType(
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_member),
     File.getFileNode(),
-    getNonCompileUnitScope(Scope),
+    DIScope(getNonCompileUnitScope(Scope)).generateRef(),
     MDString::get(VMContext, Name),
     ConstantInt::get(Type::getInt32Ty(VMContext), LineNumber),
     ConstantInt::get(Type::getInt64Ty(VMContext), SizeInBits),
diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index dc22db3b01..e0b59649a7 100644
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -446,12 +446,18 @@ static bool isScopeRef(const Value *Val) {
          (isa<MDNode>(Val) && DIScope(cast<MDNode>(Val)).isScope());
 }
 
+/// Check if a field at position Elt of a MDNode can be a ScopeRef.
+static bool fieldIsScopeRef(const MDNode *DbgNode, unsigned Elt) {
+  Value *Fld = getField(DbgNode, Elt);
+  return isScopeRef(Fld);
+}
+
 /// Verify - Verify that a type descriptor is well formed.
 bool DIType::Verify() const {
   if (!isType())
     return false;
   // Make sure Context @ field 2 is MDNode.
-  if (!fieldIsMDNode(DbgNode, 2))
+  if (!fieldIsScopeRef(DbgNode, 2))
     return false;
 
   // FIXME: Sink this into the various subclass verifies.
@@ -956,11 +962,13 @@ void DebugInfoFinder::reset() {
   TYs.clear();
   Scopes.clear();
   NodesSeen.clear();
+  TypeIdentifierMap.clear();
 }
 
 /// processModule - Process entire module and collect debug info.
 void DebugInfoFinder::processModule(const Module &M) {
   if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
+    TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
     for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
       DICompileUnit CU(CU_Nodes->getOperand(i));
       addCompileUnit(CU);
@@ -1010,7 +1018,7 @@ void DebugInfoFinder::processLocation(DILocation Loc) {
 void DebugInfoFinder::processType(DIType DT) {
   if (!addType(DT))
     return;
-  processScope(DT.getContext());
+  processScope(DT.getContext().resolve(TypeIdentifierMap));
   if (DT.isCompositeType()) {
     DICompositeType DCT(DT);
     processType(DCT.getTypeDerivedFrom());
diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index d939084052..b6d148b377 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -170,6 +170,8 @@ namespace {
       Finder.reset();
 
       DL = getAnalysisIfAvailable<DataLayout>();
+      if (!DisableDebugInfoVerifier)
+        Finder.processModule(M);
 
       // We must abort before returning back to the pass manager, or else the
       // pass manager may try to run other passes on the broken module.
@@ -2305,8 +2307,6 @@ void Verifier::visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI) {
 void Verifier::verifyDebugInfo(Module &M) {
   // Verify Debug Info.
   if (!DisableDebugInfoVerifier) {
-    Finder.processModule(M);
-
     for (DebugInfoFinder::iterator I = Finder.compile_unit_begin(),
          E = Finder.compile_unit_end(); I != E; ++I)
       Assert1(DICompileUnit(*I).Verify(), "DICompileUnit does not Verify!", *I);