3 files changed, 20 insertions, 12 deletions
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 676c48fe5c67..333d14a11af5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -621,6 +621,7 @@ void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(
   auto *SP = cast<DISubprogram>(Scope->getScopeNode());
 
   DIE *ContextDIE;
+  DwarfCompileUnit *ContextCU = this;
 
   if (includeMinimalInlineScopes())
     ContextDIE = &getUnitDie();
@@ -631,18 +632,23 @@ void DwarfCompileUnit::constructAbstractSubprogramScopeDIE(
   else if (auto *SPDecl = SP->getDeclaration()) {
     ContextDIE = &getUnitDie();
     getOrCreateSubprogramDIE(SPDecl);
-  } else
+  } else {
     ContextDIE = getOrCreateContextDIE(resolve(SP->getScope()));
+    // The scope may be shared with a subprogram that has already been
+    // constructed in another CU, in which case we need to construct this
+    // subprogram in the same CU.
+    ContextCU = DD->lookupCU(ContextDIE->getUnitDie());
+  }
 
   // Passing null as the associated node because the abstract definition
   // shouldn't be found by lookup.
-  AbsDef = &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
-  applySubprogramAttributesToDefinition(SP, *AbsDef);
+  AbsDef = &ContextCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
+  ContextCU->applySubprogramAttributesToDefinition(SP, *AbsDef);
 
-  if (!includeMinimalInlineScopes())
-    addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
-  if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
-    addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
+  if (!ContextCU->includeMinimalInlineScopes())
+    ContextCU->addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
+  if (DIE *ObjectPointer = ContextCU->createAndAddScopeChildren(Scope, *AbsDef))
+    ContextCU->addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
 }
 
 DIE *DwarfCompileUnit::constructImportedEntityDIE(
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 5dfe06c64ec2..78ee9a162029 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -283,7 +283,7 @@ class DwarfDebug : public DebugHandlerBase {
   // 0, referencing the comp_dir of all the type units that use it.
   MCDwarfDwoLineTable SplitTypeUnitFileTable;
   /// @}
-  
+
   /// True iff there are multiple CUs in this module.
   bool SingleCU;
   bool IsDarwin;
@@ -562,6 +562,9 @@ public:
   bool isLexicalScopeDIENull(LexicalScope *Scope);
 
   bool hasDwarfPubSections(bool includeMinimalInlineScopes) const;
+
+  /// Find the matching DwarfCompileUnit for the given CU DIE.
+  DwarfCompileUnit *lookupCU(const DIE *Die) { return CUDieMap.lookup(Die); }
 };
 } // End of namespace llvm
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfExpression.cpp b/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
index fe38ee805682..3a8568cf39ae 100644
--- a/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
@@ -131,13 +131,12 @@ bool DwarfExpression::addMachineReg(const TargetRegisterInfo &TRI,
 
     // Intersection between the bits we already emitted and the bits
     // covered by this subregister.
-    SmallBitVector Intersection(RegSize, false);
-    Intersection.set(Offset, Offset + Size);
-    Intersection ^= Coverage;
+    SmallBitVector CurSubReg(RegSize, false);
+    CurSubReg.set(Offset, Offset + Size);
 
     // If this sub-register has a DWARF number and we haven't covered
     // its range, emit a DWARF piece for it.
-    if (Reg >= 0 && Intersection.any()) {
+    if (Reg >= 0 && CurSubReg.test(Coverage)) {
       // Emit a piece for any gap in the coverage.
       if (Offset > CurPos)
         DwarfRegs.push_back({-1, Offset - CurPos, nullptr});