5 files changed, 32 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.cpp b/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.cpp
index f483d532ff0..8c6109880af 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.cpp
@@ -42,4 +42,6 @@ DebugLocStream::ListBuilder::~ListBuilder() {
     return;
   V.initializeDbgValue(&MI);
   V.setDebugLocListIndex(ListIndex);
+  if (TagOffset)
+    V.setDebugLocListTagOffset(*TagOffset);
 }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.h b/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.h
index 0db86b09d19..10019a4720e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugLocStream.h
@@ -159,11 +159,17 @@ class DebugLocStream::ListBuilder {
   DbgVariable &V;
   const MachineInstr &MI;
   size_t ListIndex;
+  Optional<uint8_t> TagOffset;
 
 public:
   ListBuilder(DebugLocStream &Locs, DwarfCompileUnit &CU, AsmPrinter &Asm,
               DbgVariable &V, const MachineInstr &MI)
-      : Locs(Locs), Asm(Asm), V(V), MI(MI), ListIndex(Locs.startList(&CU)) {}
+      : Locs(Locs), Asm(Asm), V(V), MI(MI), ListIndex(Locs.startList(&CU)),
+        TagOffset(None) {}
+
+  void setTagOffset(uint8_t TO) {
+    TagOffset = TO;
+  }
 
   /// Finalize the list.
   ///
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 4e90c10e3e9..0f3d8c689fa 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -615,6 +615,10 @@ DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
   unsigned Offset = DV.getDebugLocListIndex();
   if (Offset != ~0U) {
     addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
+    auto TagOffset = DV.getDebugLocListTagOffset();
+    if (TagOffset)
+      addUInt(*VariableDie, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
+              *TagOffset);
     return VariableDie;
   }
 
@@ -632,6 +636,10 @@ DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
         DwarfExpr.addUnsignedConstant(DVal->getInt());
         DwarfExpr.addExpression(Expr);
         addBlock(*VariableDie, dwarf::DW_AT_location, DwarfExpr.finalize());
+        if (DwarfExpr.TagOffset)
+          addUInt(*VariableDie, dwarf::DW_AT_LLVM_tag_offset,
+                  dwarf::DW_FORM_data1, *DwarfExpr.TagOffset);
+
       } else
         addConstantValue(*VariableDie, DVal->getInt(), DV.getType());
     } else if (DVal->isConstantFP()) {
@@ -1198,6 +1206,10 @@ void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
 
   // Now attach the location information to the DIE.
   addBlock(Die, Attribute, DwarfExpr.finalize());
+
+  if (DwarfExpr.TagOffset)
+    addUInt(Die, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
+            *DwarfExpr.TagOffset);
 }
 
 /// Start with the address based on the location provided, and generate the
@@ -1228,6 +1240,10 @@ void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
 
   // Now attach the location information to the DIE.
   addBlock(Die, Attribute, DwarfExpr.finalize());
+
+  if (DwarfExpr.TagOffset)
+    addUInt(Die, dwarf::DW_AT_LLVM_tag_offset, dwarf::DW_FORM_data1,
+            *DwarfExpr.TagOffset);
 }
 
 /// Add a Dwarf loclistptr attribute data and value.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 0a20de505a1..098b5a91d6e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2275,6 +2275,8 @@ void DebugLocEntry::finalize(const AsmPrinter &AP,
     DwarfDebug::emitDebugLocValue(AP, BT, Value, DwarfExpr);
   }
   DwarfExpr.finalize();
+  if (DwarfExpr.TagOffset)
+    List.setTagOffset(*DwarfExpr.TagOffset);
 }
 
 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry,
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 03949dbddea..bdd1b255c02 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -118,6 +118,9 @@ public:
 class DbgVariable : public DbgEntity {
   /// Offset in DebugLocs.
   unsigned DebugLocListIndex = ~0u;
+  /// DW_OP_LLVM_tag_offset value from DebugLocs.
+  Optional<uint8_t> DebugLocListTagOffset;
+
   /// Single value location description.
   std::unique_ptr<DbgValueLoc> ValueLoc = nullptr;
 
@@ -174,6 +177,8 @@ public:
 
   void setDebugLocListIndex(unsigned O) { DebugLocListIndex = O; }
   unsigned getDebugLocListIndex() const { return DebugLocListIndex; }
+  void setDebugLocListTagOffset(uint8_t O) { DebugLocListTagOffset = O; }
+  Optional<uint8_t> getDebugLocListTagOffset() const { return DebugLocListTagOffset; }
   StringRef getName() const { return getVariable()->getName(); }
   const DbgValueLoc *getValueLoc() const { return ValueLoc.get(); }
   /// Get the FI entries, sorted by fragment offset.