4 files changed, 24 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index c4d5b717b25..84b86a71fa5 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -319,8 +319,10 @@ DIEUnit::DIEUnit(uint16_t V, uint8_t A, dwarf::Tag UnitTag)
 {
   Die.Owner = this;
   assert((UnitTag == dwarf::DW_TAG_compile_unit ||
+          UnitTag == dwarf::DW_TAG_skeleton_unit ||
           UnitTag == dwarf::DW_TAG_type_unit ||
-          UnitTag == dwarf::DW_TAG_partial_unit) && "expected a unit TAG");
+          UnitTag == dwarf::DW_TAG_partial_unit) &&
+         "expected a unit TAG");
 }
 
 void DIEValue::EmitValue(const AsmPrinter *AP) const {
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 9578e01abdd..4e90c10e3e9 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -52,10 +52,23 @@
 
 using namespace llvm;
 
+static dwarf::Tag GetCompileUnitType(UnitKind Kind, DwarfDebug *DW) {
+
+  //  According to DWARF Debugging Information Format Version 5,
+  //  3.1.2 Skeleton Compilation Unit Entries:
+  //  "When generating a split DWARF object file (see Section 7.3.2
+  //  on page 187), the compilation unit in the .debug_info section
+  //  is a "skeleton" compilation unit with the tag DW_TAG_skeleton_unit"
+  if (DW->getDwarfVersion() >= 5 && Kind == UnitKind::Skeleton)
+    return dwarf::DW_TAG_skeleton_unit;
+
+  return dwarf::DW_TAG_compile_unit;
+}
+
 DwarfCompileUnit::DwarfCompileUnit(unsigned UID, const DICompileUnit *Node,
                                    AsmPrinter *A, DwarfDebug *DW,
-                                   DwarfFile *DWU)
-    : DwarfUnit(dwarf::DW_TAG_compile_unit, Node, A, DW, DWU), UniqueID(UID) {
+                                   DwarfFile *DWU, UnitKind Kind)
+    : DwarfUnit(GetCompileUnitType(Kind, DW), Node, A, DW, DWU), UniqueID(UID) {
   insertDIE(Node, &getUnitDie());
   MacroLabelBegin = Asm->createTempSymbol("cu_macro_begin");
 }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index 1b7ea2673ac..8491d078ed8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -40,6 +40,8 @@ class MCExpr;
 class MCSymbol;
 class MDNode;
 
+enum class UnitKind { Skeleton, Full };
+
 class DwarfCompileUnit final : public DwarfUnit {
   /// A numeric ID unique among all CUs in the module
   unsigned UniqueID;
@@ -104,7 +106,8 @@ class DwarfCompileUnit final : public DwarfUnit {
 
 public:
   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
-                   DwarfDebug *DW, DwarfFile *DWU);
+                   DwarfDebug *DW, DwarfFile *DWU,
+                   UnitKind Kind = UnitKind::Full);
 
   bool hasRangeLists() const { return HasRangeLists; }
   unsigned getUniqueID() const { return UniqueID; }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index a8fe6962dfc..bddb8bf3532 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2821,7 +2821,8 @@ void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
 
   auto OwnedUnit = std::make_unique<DwarfCompileUnit>(
-      CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
+      CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder,
+      UnitKind::Skeleton);
   DwarfCompileUnit &NewCU = *OwnedUnit;
   NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());