[DebugInfo] Verifier for DILabel and llvm.dbg.label.

lib/IR/Verifier.cpp

#include "llvm/IR/Metadata.def"
   void visitSwitchInst(SwitchInst &SI);
   void visitIndirectBrInst(IndirectBrInst &BI);
   void visitSelectInst(SelectInst &SI);
   void visitUserOp1(Instruction &I);
   void visitUserOp2(Instruction &I) { visitUserOp1(I); }
   void visitIntrinsicCallSite(Intrinsic::ID ID, CallSite CS);
   void visitConstrainedFPIntrinsic(ConstrainedFPIntrinsic &FPI);
   void visitDbgIntrinsic(StringRef Kind, DbgInfoIntrinsic &DII);
+  void visitDbgLabelIntrinsic(StringRef Kind, DbgLabelInst &DLI);
   void visitAtomicCmpXchgInst(AtomicCmpXchgInst &CXI);
   void visitAtomicRMWInst(AtomicRMWInst &RMWI);
   void visitFenceInst(FenceInst &FI);
   void visitAllocaInst(AllocaInst &AI);
   void visitExtractValueInst(ExtractValueInst &EVI);
   void visitInsertValueInst(InsertValueInst &IVI);
   void visitEHPadPredecessors(Instruction &I);
   void visitLandingPadInst(LandingPadInst &LPI);
void Verifier::visitDILocalVariable(const DILocalVariable &N) {
   visitDIVariable(N);
 
   AssertDI(isType(N.getRawType()), "invalid type ref", &N, N.getRawType());
   AssertDI(N.getTag() == dwarf::DW_TAG_variable, "invalid tag", &N);
   AssertDI(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
            "local variable requires a valid scope", &N, N.getRawScope());
 }
 
+void Verifier::visitDILabel(const DILabel &N) {
+  if (auto *S = N.getRawScope())
+    AssertDI(isa<DIScope>(S), "invalid scope", &N, S);
+  if (auto *F = N.getRawFile())
+    AssertDI(isa<DIFile>(F), "invalid file", &N, F);
+
+  AssertDI(N.getTag() == dwarf::DW_TAG_label, "invalid tag", &N);
+  AssertDI(N.getRawScope() && isa<DILocalScope>(N.getRawScope()),
+           "label requires a valid scope", &N, N.getRawScope());
+}
+
 void Verifier::visitDIExpression(const DIExpression &N) {
   AssertDI(N.isValid(), "invalid expression", &N);
 }
 
 void Verifier::visitDIGlobalVariableExpression(
     const DIGlobalVariableExpression &GVE) {
   AssertDI(GVE.getVariable(), "missing variable");
   if (auto *Var = GVE.getVariable())
case Intrinsic::dbg_declare: // llvm.dbg.declare
     visitDbgIntrinsic("declare", cast<DbgInfoIntrinsic>(*CS.getInstruction()));
     break;
   case Intrinsic::dbg_addr: // llvm.dbg.addr
     visitDbgIntrinsic("addr", cast<DbgInfoIntrinsic>(*CS.getInstruction()));
     break;
   case Intrinsic::dbg_value: // llvm.dbg.value
     visitDbgIntrinsic("value", cast<DbgInfoIntrinsic>(*CS.getInstruction()));
     break;
+  case Intrinsic::dbg_label: // llvm.dbg.label
+    visitDbgLabelIntrinsic("label", cast<DbgLabelInst>(*CS.getInstruction()));
+    break;
   case Intrinsic::memcpy:
   case Intrinsic::memmove:
   case Intrinsic::memset: {
     const auto *MI = cast<MemIntrinsic>(CS.getInstruction());
     auto IsValidAlignment = [&](unsigned Alignment) -> bool {
       return Alignment == 0 || isPowerOf2_32(Alignment);
     };
     Assert(IsValidAlignment(MI->getDestAlignment()),
void Verifier::visitDbgIntrinsic(StringRef Kind, DbgInfoIntrinsic &DII) {
   AssertDI(VarSP == LocSP, "mismatched subprogram between llvm.dbg." + Kind +
                                " variable and !dbg attachment",
            &DII, BB, F, Var, Var->getScope()->getSubprogram(), Loc,
            Loc->getScope()->getSubprogram());
 
   verifyFnArgs(DII);
 }
 
+void Verifier::visitDbgLabelIntrinsic(StringRef Kind, DbgLabelInst &DLI) {
+  AssertDI(isa<DILabel>(DLI.getRawVariable()),
+         "invalid llvm.dbg." + Kind + " intrinsic variable", &DLI,
+         DLI.getRawVariable());
+
+  // Ignore broken !dbg attachments; they're checked elsewhere.
+  if (MDNode *N = DLI.getDebugLoc().getAsMDNode())
+    if (!isa<DILocation>(N))
+      return;
+
+  BasicBlock *BB = DLI.getParent();
+  Function *F = BB ? BB->getParent() : nullptr;
+
+  // The scopes for variables and !dbg attachments must agree.
+  DILabel *Label = DLI.getLabel();
+  DILocation *Loc = DLI.getDebugLoc();
+  Assert(Loc, "llvm.dbg." + Kind + " intrinsic requires a !dbg attachment",
+         &DLI, BB, F);
+
+  DISubprogram *LabelSP = getSubprogram(Label->getRawScope());
+  DISubprogram *LocSP = getSubprogram(Loc->getRawScope());
+  if (!LabelSP || !LocSP)
+    return; // Broken scope chains are checked elsewhere.
+
+  AssertDI(LabelSP == LocSP, "mismatched subprogram between llvm.dbg." + Kind +
+                             " variable and !dbg attachment",
+           &DLI, BB, F, Label, Label->getScope()->getSubprogram(), Loc,
+           Loc->getScope()->getSubprogram());
+}
+
 void Verifier::verifyFragmentExpression(const DbgInfoIntrinsic &I) {
+  if (dyn_cast<DbgLabelInst>(&I))
+    return;
+
   DILocalVariable *V = dyn_cast_or_null<DILocalVariable>(I.getRawVariable());
   DIExpression *E = dyn_cast_or_null<DIExpression>(I.getRawExpression());
 
   // We don't know whether this intrinsic verified correctly.
   if (!V || !E || !E->isValid())
     return;
 
   // Nothing to do if this isn't a DW_OP_LLVM_fragment expression.