4 files changed, 8 insertions, 53 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index a51342a7fee..0daca72b30d 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -695,25 +695,6 @@ void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
       applySubprogramAttributesToDefinition(SP, *D);
   }
 }
-void DwarfCompileUnit::collectDeadVariables(const DISubprogram *SP) {
-  assert(SP && "CU's subprogram list contains a non-subprogram");
-  assert(SP->isDefinition() &&
-         "CU's subprogram list contains a subprogram declaration");
-  auto Variables = SP->getVariables();
-  if (Variables.size() == 0)
-    return;
-
-  DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
-  if (!SPDIE)
-    SPDIE = getDIE(SP);
-  assert(SPDIE);
-  for (const DILocalVariable *DV : Variables) {
-    DbgVariable NewVar(DV, /* IA */ nullptr, DD);
-    auto VariableDie = constructVariableDIE(NewVar);
-    applyVariableAttributes(NewVar, *VariableDie);
-    SPDIE->addChild(std::move(VariableDie));
-  }
-}
 
 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
   // Don't bother labeling the .dwo unit, as its offset isn't used.
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index bacf87d95c4..1170b379080 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -180,8 +180,6 @@ public:
 
   void finishSubprogramDefinition(const DISubprogram *SP);
 
-  void collectDeadVariables(const DISubprogram *SP);
-
   /// Set the skeleton unit associated with this unit.
   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d9d265ef2b9..9195ca310a2 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -526,32 +526,10 @@ void DwarfDebug::finishVariableDefinitions() {
 
 void DwarfDebug::finishSubprogramDefinitions() {
   for (const auto &P : SPMap)
-    forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
-      CU.finishSubprogramDefinition(cast<DISubprogram>(P.first));
-    });
-}
-
-// Collect info for variables that were optimized out.
-void DwarfDebug::collectDeadVariables() {
-  const Module *M = MMI->getModule();
-
-  if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
-    for (MDNode *N : CU_Nodes->operands()) {
-      auto *TheCU = cast<DICompileUnit>(N);
-      if (TheCU->getEmissionKind() == DICompileUnit::NoDebug)
-        continue;
-
-      // Construct subprogram DIE and add variables DIEs.
-      DwarfCompileUnit *SPCU =
-          static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
-      assert(SPCU && "Unable to find Compile Unit!");
-      for (auto *SP : TheCU->getSubprograms()) {
-        if (ProcessedSPNodes.count(SP) != 0)
-          continue;
-        SPCU->collectDeadVariables(SP);
-      }
-    }
-  }
+    if (ProcessedSPNodes.count(P.first))
+      forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
+          CU.finishSubprogramDefinition(cast<DISubprogram>(P.first));
+        });
 }
 
 void DwarfDebug::finalizeModuleInfo() {
@@ -561,9 +539,6 @@ void DwarfDebug::finalizeModuleInfo() {
 
   finishVariableDefinitions();
 
-  // Collect info for variables that were optimized out.
-  collectDeadVariables();
-
   // Handle anything that needs to be done on a per-unit basis after
   // all other generation.
   for (const auto &P : CUMap) {
@@ -1129,6 +1104,10 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
     PrevCU = nullptr;
     CurFn = nullptr;
     DebugHandlerBase::endFunction(MF);
+    // Mark functions with no debug info on any instructions, but a
+    // valid DISubprogram as processed.
+    if (auto *SP = MF->getFunction()->getSubprogram())
+      ProcessedSPNodes.insert(SP);
     return;
   }
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index f0859ec1a8f..1f83434c530 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -320,9 +320,6 @@ class DwarfDebug : public DebugHandlerBase {
   /// Construct a DIE for this abstract scope.
   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
 
-  /// Collect info for variables that were optimized out.
-  void collectDeadVariables();
-
   void finishVariableDefinitions();
 
   void finishSubprogramDefinitions();