DebugInfo: Generalize debug info location handling

This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.

This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.

I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.

Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.

I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.

llvm-svn: 224385

15 files changed, 92 insertions, 184 deletions

diff --git a/clang/lib/CodeGen/CGBlocks.cpp b/clang/lib/CodeGen/CGBlocks.cpp
index bdb3eaf5499..be6d8d849bf 100644
--- a/clang/lib/CodeGen/CGBlocks.cpp
+++ b/clang/lib/CodeGen/CGBlocks.cpp
@@ -874,7 +874,7 @@ llvm::Value *CodeGenFunction::EmitBlockLiteral(const CGBlockInfo &blockInfo) {
       // locations of subexpressions in the initialization.
       EmitExprAsInit(&l2r, &blockFieldPseudoVar,
                      MakeAddrLValue(blockField, type, align),
-                     /*captured by init*/ false, SourceLocation());
+                     /*captured by init*/ false);
     }
 
     // Activate the cleanup if layout pushed one.
@@ -1175,7 +1175,7 @@ CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
     Alloca->setAlignment(Align);
     // Set the DebugLocation to empty, so the store is recognized as a
     // frame setup instruction by llvm::DwarfDebug::beginFunction().
-    NoLocation NL(*this, Builder);
+    ApplyDebugLocation NL(*this);
     Builder.CreateAlignedStore(BlockPointer, Alloca, Align);
     BlockPointerDbgLoc = Alloca;
   }
@@ -1326,9 +1326,9 @@ CodeGenFunction::GenerateCopyHelperFunction(const CGBlockInfo &blockInfo) {
                                           false,
                                           false);
   // Create a scope with an artificial location for the body of this function.
-  ArtificialLocation AL(*this, Builder);
+  ApplyDebugLocation NL(*this);
   StartFunction(FD, C.VoidTy, Fn, FI, args);
-  AL.Emit();
+  ArtificialLocation AL(*this);
 
   llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
 
@@ -1497,9 +1497,9 @@ CodeGenFunction::GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo) {
                                           nullptr, SC_Static,
                                           false, false);
   // Create a scope with an artificial location for the body of this function.
-  ArtificialLocation AL(*this, Builder);
+  ApplyDebugLocation NL(*this);
   StartFunction(FD, C.VoidTy, Fn, FI, args);
-  AL.Emit();
+  ArtificialLocation AL(*this);
 
   llvm::Type *structPtrTy = blockInfo.StructureType->getPointerTo();
 
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index 5ffab603ac8..92c694a76de 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -544,6 +544,7 @@ static void EmitMemberInitializer(CodeGenFunction &CGF,
                                   CXXCtorInitializer *MemberInit,
                                   const CXXConstructorDecl *Constructor,
                                   FunctionArgList &Args) {
+  ApplyDebugLocation Loc(CGF, MemberInit->getMemberLocation());
   assert(MemberInit->isAnyMemberInitializer() &&
          "Must have member initializer!");
   assert(MemberInit->getInit() && "Must have initializer!");
@@ -597,26 +598,25 @@ static void EmitMemberInitializer(CodeGenFunction &CGF,
   ArrayRef<VarDecl *> ArrayIndexes;
   if (MemberInit->getNumArrayIndices())
     ArrayIndexes = MemberInit->getArrayIndexes();
-  CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit(), ArrayIndexes,
-                              MemberInit->getMemberLocation());
+  ApplyDebugLocation DL(CGF, MemberInit->getMemberLocation());
+  CGF.EmitInitializerForField(Field, LHS, MemberInit->getInit(), ArrayIndexes);
 }
 
-void CodeGenFunction::EmitInitializerForField(FieldDecl *Field, LValue LHS,
-                                              Expr *Init,
-                                              ArrayRef<VarDecl *> ArrayIndexes,
-                                              SourceLocation DbgLoc) {
+void CodeGenFunction::EmitInitializerForField(
+    FieldDecl *Field, LValue LHS, Expr *Init,
+    ArrayRef<VarDecl *> ArrayIndexes) {
   QualType FieldType = Field->getType();
   switch (getEvaluationKind(FieldType)) {
   case TEK_Scalar:
     if (LHS.isSimple()) {
-      EmitExprAsInit(Init, Field, LHS, false, DbgLoc);
+      EmitExprAsInit(Init, Field, LHS, false);
     } else {
       RValue RHS = RValue::get(EmitScalarExpr(Init));
       EmitStoreThroughLValue(RHS, LHS);
     }
     break;
   case TEK_Complex:
-    EmitComplexExprIntoLValue(Init, LHS, /*isInit*/ true, DbgLoc);
+    EmitComplexExprIntoLValue(Init, LHS, /*isInit*/ true);
     break;
   case TEK_Aggregate: {
     llvm::Value *ArrayIndexVar = nullptr;
@@ -783,8 +783,6 @@ void CodeGenFunction::EmitConstructorBody(FunctionArgList &Args) {
   // delegation optimization.
   if (CtorType == Ctor_Complete && IsConstructorDelegationValid(Ctor) &&
       CGM.getTarget().getCXXABI().hasConstructorVariants()) {
-    if (CGDebugInfo *DI = getDebugInfo()) 
-      DI->EmitLocation(Builder, Ctor->getLocEnd());
     EmitDelegateCXXConstructorCall(Ctor, Ctor_Base, Args, Ctor->getLocEnd());
     return;
   }
diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp
index d81e3a597b8..18ed3e543d2 100644
--- a/clang/lib/CodeGen/CGCleanup.cpp
+++ b/clang/lib/CodeGen/CGCleanup.cpp
@@ -861,10 +861,7 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
 
   // Emit the EH cleanup if required.
   if (RequiresEHCleanup) {
-    CGDebugInfo *DI = getDebugInfo();
-    SaveAndRestoreLocation AutoRestoreLocation(*this, Builder);
-    if (DI)
-      DI->EmitLocation(Builder, CurEHLocation);
+    ApplyDebugLocation AutoRestoreLocation(*this, CurEHLocation);
 
     CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
 
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 5bf460f2b82..7452ac98114 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -52,54 +52,35 @@ CGDebugInfo::~CGDebugInfo() {
          "Region stack mismatch, stack not empty!");
 }
 
-SaveAndRestoreLocation::SaveAndRestoreLocation(CodeGenFunction &CGF,
-                                               CGBuilderTy &B)
-    : DI(CGF.getDebugInfo()), Builder(B) {
-  if (DI) {
-    SavedLoc = DI->getLocation();
-    DI->CurLoc = SourceLocation();
-  }
-}
-
-SaveAndRestoreLocation::~SaveAndRestoreLocation() {
-  if (DI)
-    DI->EmitLocation(Builder, SavedLoc);
-}
-
-NoLocation::NoLocation(CodeGenFunction &CGF, CGBuilderTy &B)
-    : SaveAndRestoreLocation(CGF, B) {
-  if (DI)
-    Builder.SetCurrentDebugLocation(llvm::DebugLoc());
-}
-
-NoLocation::~NoLocation() {
-  if (DI)
-    assert(Builder.getCurrentDebugLocation().isUnknown());
-}
-
-ArtificialLocation::ArtificialLocation(CodeGenFunction &CGF, CGBuilderTy &B)
-    : SaveAndRestoreLocation(CGF, B) {
-  if (DI)
-    Builder.SetCurrentDebugLocation(llvm::DebugLoc());
-}
-
-void ArtificialLocation::Emit() {
-  if (DI) {
-    // Sync the Builder.
-    DI->EmitLocation(Builder, SavedLoc);
-    DI->CurLoc = SourceLocation();
+ArtificialLocation::ArtificialLocation(CodeGenFunction &CGF)
+    : ApplyDebugLocation(CGF) {
+  if (auto *DI = CGF.getDebugInfo()) {
     // Construct a location that has a valid scope, but no line info.
     assert(!DI->LexicalBlockStack.empty());
     llvm::DIDescriptor Scope(DI->LexicalBlockStack.back());
-    Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(0, 0, Scope));
+    CGF.Builder.SetCurrentDebugLocation(llvm::DebugLoc::get(0, 0, Scope));
+  }
+}
+
+ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF,
+                                       SourceLocation TemporaryLocation,
+                                       bool ForceColumnInfo)
+    : CGF(CGF) {
+  if (auto *DI = CGF.getDebugInfo()) {
+    OriginalLocation = CGF.Builder.getCurrentDebugLocation();
+    if (TemporaryLocation.isInvalid())
+      CGF.Builder.SetCurrentDebugLocation(llvm::DebugLoc());
+    else
+      DI->EmitLocation(CGF.Builder, TemporaryLocation, ForceColumnInfo);
   }
 }
 
-ArtificialLocation::~ArtificialLocation() {
-  if (DI)
-    assert(Builder.getCurrentDebugLocation().getLine() == 0);
+ApplyDebugLocation::~ApplyDebugLocation() {
+  CGF.Builder.SetCurrentDebugLocation(OriginalLocation);
 }
 
+/// ArtificialLocation - An RAII object that temporarily switches to
+/// an artificial debug location that has a valid scope, but no line
 void CGDebugInfo::setLocation(SourceLocation Loc) {
   // If the new location isn't valid return.
   if (Loc.isInvalid())
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 9649e296160..274cbc4f365 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -448,27 +448,16 @@ private:
   }
 };
 
-/// SaveAndRestoreLocation - An RAII object saves the current location
-/// and automatically restores it to the original value.
-class SaveAndRestoreLocation {
+class ApplyDebugLocation {
 protected:
-  SourceLocation SavedLoc;
-  CGDebugInfo *DI;
-  CGBuilderTy &Builder;
-public:
-  SaveAndRestoreLocation(CodeGenFunction &CGF, CGBuilderTy &B);
-  /// Autorestore everything back to normal.
-  ~SaveAndRestoreLocation();
-};
+  llvm::DebugLoc OriginalLocation;
+  CodeGenFunction &CGF;
 
-/// NoLocation - An RAII object that temporarily disables debug
-/// locations. This is useful for emitting instructions that should be
-/// counted towards the function prologue.
-class NoLocation : public SaveAndRestoreLocation {
 public:
-  NoLocation(CodeGenFunction &CGF, CGBuilderTy &B);
-  /// Autorestore everything back to normal.
-  ~NoLocation();
+  ApplyDebugLocation(CodeGenFunction &CGF,
+                     SourceLocation TemporaryLocation = SourceLocation(),
+                     bool ForceColumnInfo = false);
+  ~ApplyDebugLocation();
 };
 
 /// ArtificialLocation - An RAII object that temporarily switches to
@@ -482,16 +471,9 @@ public:
 /// This is necessary because passing an empty SourceLocation to
 /// CGDebugInfo::setLocation() will result in the last valid location
 /// being reused.
-class ArtificialLocation : public SaveAndRestoreLocation {
+class ArtificialLocation : public ApplyDebugLocation {
 public:
-  ArtificialLocation(CodeGenFunction &CGF, CGBuilderTy &B);
-
-  /// Set the current location to line 0, but within the current scope
-  /// (= the top of the LexicalBlockStack).
-  void Emit();
-
-  /// Autorestore everything back to normal.
-  ~ArtificialLocation();
+  ArtificialLocation(CodeGenFunction &CGF);
 };
 
 
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 4a612c9bedf..15a1a7fb5f1 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -597,14 +597,13 @@ static void drillIntoBlockVariable(CodeGenFunction &CGF,
 }
 
 void CodeGenFunction::EmitScalarInit(const Expr *init, const ValueDecl *D,
-                                     LValue lvalue, bool capturedByInit,
-                                     SourceLocation DbgLoc) {
+                                     LValue lvalue, bool capturedByInit) {
   Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
   if (!lifetime) {
     llvm::Value *value = EmitScalarExpr(init);
     if (capturedByInit)
       drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
-    EmitStoreThroughLValue(RValue::get(value), lvalue, true, DbgLoc);
+    EmitStoreThroughLValue(RValue::get(value), lvalue, true);
     return;
   }
   
@@ -1088,6 +1087,7 @@ void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
   if (emission.wasEmittedAsGlobal()) return;
 
   const VarDecl &D = *emission.Variable;
+  ApplyDebugLocation DL(*this, D.getLocation());
   QualType type = D.getType();
 
   // If this local has an initializer, emit it now.
@@ -1126,7 +1126,7 @@ void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
   if (!constant) {
     LValue lv = MakeAddrLValue(Loc, type, alignment);
     lv.setNonGC(true);
-    return EmitExprAsInit(Init, &D, lv, capturedByInit, D.getLocation());
+    return EmitExprAsInit(Init, &D, lv, capturedByInit);
   }
 
   if (!emission.IsConstantAggregate) {
@@ -1192,26 +1192,25 @@ void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
 /// \param capturedByInit true if the variable is a __block variable
 ///   whose address is potentially changed by the initializer
 void CodeGenFunction::EmitExprAsInit(const Expr *init, const ValueDecl *D,
-                                     LValue lvalue, bool capturedByInit,
-                                     SourceLocation DbgLoc) {
+                                     LValue lvalue, bool capturedByInit) {
   QualType type = D->getType();
 
   if (type->isReferenceType()) {
     RValue rvalue = EmitReferenceBindingToExpr(init);
     if (capturedByInit)
       drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
-    EmitStoreThroughLValue(rvalue, lvalue, true, DbgLoc);
+    EmitStoreThroughLValue(rvalue, lvalue, true);
     return;
   }
   switch (getEvaluationKind(type)) {
   case TEK_Scalar:
-    EmitScalarInit(init, D, lvalue, capturedByInit, DbgLoc);
+    EmitScalarInit(init, D, lvalue, capturedByInit);
     return;
   case TEK_Complex: {
     ComplexPairTy complex = EmitComplexExpr(init);
     if (capturedByInit)
       drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
-    EmitStoreOfComplex(complex, lvalue, /*init*/ true, DbgLoc);
+    EmitStoreOfComplex(complex, lvalue, /*init*/ true);
     return;
   }
   case TEK_Aggregate:
diff --git a/clang/lib/CodeGen/CGDeclCXX.cpp b/clang/lib/CodeGen/CGDeclCXX.cpp
index e002cdf6d88..3997c8c3d4d 100644
--- a/clang/lib/CodeGen/CGDeclCXX.cpp
+++ b/clang/lib/CodeGen/CGDeclCXX.cpp
@@ -474,11 +474,11 @@ CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
                                            ArrayRef<llvm::Function *> Decls,
                                            llvm::GlobalVariable *Guard) {
   {
-    ArtificialLocation AL(*this, Builder);
+    ApplyDebugLocation NL(*this);
     StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
                   getTypes().arrangeNullaryFunction(), FunctionArgList());
     // Emit an artificial location for this function.
-    AL.Emit();
+    ArtificialLocation AL(*this);
 
     llvm::BasicBlock *ExitBlock = nullptr;
     if (Guard) {
@@ -525,11 +525,11 @@ void CodeGenFunction::GenerateCXXGlobalDtorsFunc(llvm::Function *Fn,
                   const std::vector<std::pair<llvm::WeakVH, llvm::Constant*> >
                                                 &DtorsAndObjects) {
   {
-    ArtificialLocation AL(*this, Builder);
+    ApplyDebugLocation NL(*this);
     StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
                   getTypes().arrangeNullaryFunction(), FunctionArgList());
     // Emit an artificial location for this function.
-    AL.Emit();
+    ArtificialLocation AL(*this);
 
     // Emit the dtors, in reverse order from construction.
     for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) {
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index fa89033bb0f..4b57533c609 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -734,9 +734,7 @@ llvm::BasicBlock *CodeGenFunction::EmitLandingPad() {
 
   // Save the current IR generation state.
   CGBuilderTy::InsertPoint savedIP = Builder.saveAndClearIP();
-  SaveAndRestoreLocation AutoRestoreLocation(*this, Builder);
-  if (CGDebugInfo *DI = getDebugInfo())
-    DI->EmitLocation(Builder, CurEHLocation);
+  ApplyDebugLocation AutoRestoreLocation(*this, CurEHLocation);
 
   const EHPersonality &personality = EHPersonality::get(CGM);
 
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 0b949bc502c..16b624a9c31 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1438,11 +1438,7 @@ RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
 /// lvalue, where both are guaranteed to the have the same type, and that type
 /// is 'Ty'.
 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
-                                             bool isInit,
-                                             SourceLocation DbgLoc) {
-  if (auto *DI = getDebugInfo())
-    DI->EmitLocation(Builder, DbgLoc);
-
+                                             bool isInit) {
   if (!Dst.isSimple()) {
     if (Dst.isVectorElt()) {
       // Read/modify/write the vector, inserting the new element.
@@ -2408,9 +2404,6 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
     // The element count here is the total number of non-VLA elements.
     llvm::Value *numElements = getVLASize(vla).first;
 
-    if (auto *DI = getDebugInfo())
-      DI->EmitLocation(Builder, E->getLocStart());
-
     // Effectively, the multiply by the VLA size is part of the GEP.
     // GEP indexes are signed, and scaling an index isn't permitted to
     // signed-overflow, so we use the same semantics for our explicit
@@ -2456,9 +2449,6 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
     // Propagate the alignment from the array itself to the result.
     ArrayAlignment = ArrayLV.getAlignment();
 
-    if (auto *DI = getDebugInfo())
-      DI->EmitLocation(Builder, E->getLocStart());
-
     if (getLangOpts().isSignedOverflowDefined())
       Address = Builder.CreateGEP(ArrayPtr, Args, "arrayidx");
     else
@@ -2466,8 +2456,6 @@ LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
   } else {
     // The base must be a pointer, which is not an aggregate.  Emit it.
     llvm::Value *Base = EmitScalarExpr(E->getBase());
-    if (auto *DI = getDebugInfo())
-      DI->EmitLocation(Builder, E->getLocStart());
     if (getLangOpts().isSignedOverflowDefined())
       Address = Builder.CreateGEP(Base, Idx, "arrayidx");
     else
@@ -3024,18 +3012,15 @@ RValue CodeGenFunction::EmitRValueForField(LValue LV,
 
 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
                                      ReturnValueSlot ReturnValue) {
-  if (CGDebugInfo *DI = getDebugInfo()) {
-    SourceLocation Loc = E->getLocStart();
-    // Force column info to be generated so we can differentiate
-    // multiple call sites on the same line in the debug info.
-    // FIXME: This is insufficient. Two calls coming from the same macro
-    // expansion will still get the same line/column and break debug info. It's
-    // possible that LLVM can be fixed to not rely on this uniqueness, at which
-    // point this workaround can be removed.
-    const FunctionDecl* Callee = E->getDirectCallee();
-    bool ForceColumnInfo = Callee && Callee->isInlineSpecified();
-    DI->EmitLocation(Builder, Loc, ForceColumnInfo);
-  }
+  // Force column info to be generated so we can differentiate
+  // multiple call sites on the same line in the debug info.
+  // FIXME: This is insufficient. Two calls coming from the same macro
+  // expansion will still get the same line/column and break debug info. It's
+  // possible that LLVM can be fixed to not rely on this uniqueness, at which
+  // point this workaround can be removed.
+  ApplyDebugLocation DL(*this, E->getLocStart(),
+                        E->getDirectCallee() &&
+                            E->getDirectCallee()->isInlineSpecified());
 
   // Builtins never have block type.
   if (E->getCallee()->getType()->isBlockPointerType())
@@ -3151,8 +3136,6 @@ LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
 
     RValue RV = EmitAnyExpr(E->getRHS());
     LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
-    if (CGDebugInfo *DI = getDebugInfo())
-      DI->EmitLocation(Builder, E->getLocStart());
     EmitStoreThroughLValue(RV, LV);
     return LV;
   }
diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 31f9141eebb..6d63b3ae9cf 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -187,8 +187,6 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
         unsigned ArgsToSkip = isa<CXXOperatorCallExpr>(CE) ? 1 : 0;
         llvm::Value *RHS =
             EmitLValue(*(CE->arg_begin() + ArgsToSkip)).getAddress();
-        if (auto *DI = getDebugInfo())
-          DI->EmitLocation(Builder, CE->getLocStart());
         EmitAggregateAssign(This, RHS, CE->getType());
         return RValue::get(This);
       }
@@ -754,15 +752,13 @@ static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
 }
 
 static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
-                                    QualType AllocType, llvm::Value *NewPtr,
-                                    SourceLocation DbgLoc = SourceLocation()) {
+                                    QualType AllocType, llvm::Value *NewPtr) {
   // FIXME: Refactor with EmitExprAsInit.
   CharUnits Alignment = CGF.getContext().getTypeAlignInChars(AllocType);
   switch (CGF.getEvaluationKind(AllocType)) {
   case TEK_Scalar:
     CGF.EmitScalarInit(Init, nullptr,
-                       CGF.MakeAddrLValue(NewPtr, AllocType, Alignment), false,
-                       DbgLoc);
+                       CGF.MakeAddrLValue(NewPtr, AllocType, Alignment), false);
     return;
   case TEK_Complex:
     CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType,
@@ -1020,12 +1016,12 @@ static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
                                llvm::Value *NewPtr,
                                llvm::Value *NumElements,
                                llvm::Value *AllocSizeWithoutCookie) {
+  ApplyDebugLocation DL(CGF, E->getStartLoc());
   if (E->isArray())
     CGF.EmitNewArrayInitializer(E, ElementType, NewPtr, NumElements,
                                 AllocSizeWithoutCookie);
   else if (const Expr *Init = E->getInitializer())
-    StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr,
-                            E->getStartLoc());
+    StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr);
 }
 
 /// Emit a call to an operator new or operator delete function, as implicitly
@@ -1269,9 +1265,6 @@ llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
                E->placement_arg_end(), /* CalleeDecl */ nullptr,
                /*ParamsToSkip*/ 1);
 
-  if (auto *DI = getDebugInfo())
-    DI->EmitLocation(Builder, E->getLocStart());
-
   // Emit the allocation call.  If the allocator is a global placement
   // operator, just "inline" it directly.
   RValue RV;
diff --git a/clang/lib/CodeGen/CGExprComplex.cpp b/clang/lib/CodeGen/CGExprComplex.cpp
index 2732d40093e..1580bbe6a29 100644
--- a/clang/lib/CodeGen/CGExprComplex.cpp
+++ b/clang/lib/CodeGen/CGExprComplex.cpp
@@ -81,8 +81,7 @@ public:
 
   /// EmitStoreOfComplex - Store the specified real/imag parts into the
   /// specified value pointer.
-  void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit,
-                          SourceLocation DbgLoc);
+  void EmitStoreOfComplex(ComplexPairTy Val, LValue LV, bool isInit);
 
   /// EmitComplexToComplexCast - Emit a cast from complex value Val to DestType.
   ComplexPairTy EmitComplexToComplexCast(ComplexPairTy Val, QualType SrcType,
@@ -335,11 +334,7 @@ ComplexPairTy ComplexExprEmitter::EmitLoadOfLValue(LValue lvalue,
 /// EmitStoreOfComplex - Store the specified real/imag parts into the
 /// specified value pointer.
 void ComplexExprEmitter::EmitStoreOfComplex(ComplexPairTy Val, LValue lvalue,
-                                            bool isInit,
-                                            SourceLocation DbgLoc) {
-  if (auto *DI = CGF.getDebugInfo())
-    DI->EmitLocation(CGF.Builder, DbgLoc);
-
+                                            bool isInit) {
   if (lvalue.getType()->isAtomicType())
     return CGF.EmitAtomicStore(RValue::getComplex(Val), lvalue, isInit);
 
@@ -869,7 +864,7 @@ EmitCompoundAssignLValue(const CompoundAssignOperator *E,
   // Truncate the result and store it into the LHS lvalue.
   if (LHSTy->isAnyComplexType()) {
     ComplexPairTy ResVal = EmitComplexToComplexCast(Result, OpInfo.Ty, LHSTy);
-    EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false, E->getLocStart());
+    EmitStoreOfComplex(ResVal, LHS, /*isInit*/ false);
     Val = RValue::getComplex(ResVal);
   } else {
     llvm::Value *ResVal =
@@ -914,7 +909,7 @@ LValue ComplexExprEmitter::EmitBinAssignLValue(const BinaryOperator *E,
   LValue LHS = CGF.EmitLValue(E->getLHS());
 
   // Store the result value into the LHS lvalue.
-  EmitStoreOfComplex(Val, LHS, /*isInit*/ false, E->getLocStart());
+  EmitStoreOfComplex(Val, LHS, /*isInit*/ false);
 
   return LHS;
 }
@@ -1042,19 +1037,18 @@ ComplexPairTy CodeGenFunction::EmitComplexExpr(const Expr *E, bool IgnoreReal,
 }
 
 void CodeGenFunction::EmitComplexExprIntoLValue(const Expr *E, LValue dest,
-                                                bool isInit,
-                                                SourceLocation DbgLoc) {
+                                                bool isInit) {
   assert(E && getComplexType(E->getType()) &&
          "Invalid complex expression to emit");
   ComplexExprEmitter Emitter(*this);
   ComplexPairTy Val = Emitter.Visit(const_cast<Expr*>(E));
-  Emitter.EmitStoreOfComplex(Val, dest, isInit, DbgLoc);
+  Emitter.EmitStoreOfComplex(Val, dest, isInit);
 }
 
 /// EmitStoreOfComplex - Store a complex number into the specified l-value.
 void CodeGenFunction::EmitStoreOfComplex(ComplexPairTy V, LValue dest,
-                                         bool isInit, SourceLocation DbgLoc) {
-  ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit, DbgLoc);
+                                         bool isInit) {
+  ComplexExprEmitter(*this).EmitStoreOfComplex(V, dest, isInit);
 }
 
 /// EmitLoadOfComplex - Load a complex number from the specified address.
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index a4430dffb05..ae4392d15a2 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -196,6 +196,7 @@ public:
   //===--------------------------------------------------------------------===//
 
   Value *Visit(Expr *E) {
+    ApplyDebugLocation DL(CGF, E->getLocStart());
     return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
   }
 
@@ -3041,7 +3042,7 @@ Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) {
   // Emit an unconditional branch from this block to ContBlock.
   {
     // There is no need to emit line number for unconditional branch.
-    SuppressDebugLocation S(Builder);
+    ApplyDebugLocation DL(CGF);
     CGF.EmitBlock(ContBlock);
   }
   // Insert an entry into the phi node for the edge with the value of RHSCond.
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index a003e8ab9e8..2e431256135 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -565,7 +565,7 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
   if (const Stmt *Else = S.getElse()) {
     {
       // There is no need to emit line number for unconditional branch.
-      SuppressDebugLocation S(Builder);
+      ApplyDebugLocation DL(*this);
       EmitBlock(ElseBlock);
     }
     {
@@ -574,7 +574,7 @@ void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
     }
     {
       // There is no need to emit line number for unconditional branch.
-      SuppressDebugLocation S(Builder);
+      ApplyDebugLocation DL(*this);
       EmitBranch(ContBlock);
     }
   }
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 73bb43654b4..09352f12160 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -86,13 +86,13 @@ static void EmitOMPIfClause(CodeGenFunction &CGF, const Expr *Cond,
   // Emit the 'else' code if present.
   {
     // There is no need to emit line number for unconditional branch.
-    SuppressDebugLocation SDL(CGF.Builder);
+    ApplyDebugLocation DL(CGF);
     CGF.EmitBlock(ElseBlock);
   }
   CodeGen(/*ThenBlock*/ false);
   {
     // There is no need to emit line number for unconditional branch.
-    SuppressDebugLocation SDL(CGF.Builder);
+    ApplyDebugLocation DL(CGF);
     CGF.EmitBranch(ContBlock);
   }
   // Emit the continuation block for code after the if.
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 2e1e400041a..e37ceca2942 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -93,19 +93,6 @@ enum TypeEvaluationKind {
   TEK_Aggregate
 };
 
-class SuppressDebugLocation {
-  llvm::DebugLoc CurLoc;
-  llvm::IRBuilderBase &Builder;
-public:
-  SuppressDebugLocation(llvm::IRBuilderBase &Builder)
-      : CurLoc(Builder.getCurrentDebugLocation()), Builder(Builder) {
-    Builder.SetCurrentDebugLocation(llvm::DebugLoc());
-  }
-  ~SuppressDebugLocation() {
-    Builder.SetCurrentDebugLocation(CurLoc);
-  }
-};
-
 /// CodeGenFunction - This class organizes the per-function state that is used
 /// while generating LLVM code.
 class CodeGenFunction : public CodeGenTypeCache {
@@ -1300,8 +1287,7 @@ public:
                         FunctionArgList &Args);
 
   void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init,
-                               ArrayRef<VarDecl *> ArrayIndexes,
-                               SourceLocation DbgLoc = SourceLocation());
+                               ArrayRef<VarDecl *> ArrayIndexes);
 
   /// InitializeVTablePointer - Initialize the vtable pointer of the given
   /// subobject.
@@ -1546,7 +1532,7 @@ public:
   /// EmitExprAsInit - Emits the code necessary to initialize a
   /// location in memory with the given initializer.
   void EmitExprAsInit(const Expr *init, const ValueDecl *D, LValue lvalue,
-                      bool capturedByInit, SourceLocation DbgLoc);
+                      bool capturedByInit);
 
   /// hasVolatileMember - returns true if aggregate type has a volatile
   /// member.
@@ -1833,8 +1819,7 @@ public:
   void EmitVarDecl(const VarDecl &D);
 
   void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue,
-                      bool capturedByInit,
-                      SourceLocation DbgLoc = SourceLocation());
+                      bool capturedByInit);
   void EmitScalarInit(llvm::Value *init, LValue lvalue);
 
   typedef void SpecialInitFn(CodeGenFunction &Init, const VarDecl &D,
@@ -2164,8 +2149,7 @@ public:
   /// EmitStoreThroughLValue - Store the specified rvalue into the specified
   /// lvalue, where both are guaranteed to the have the same type, and that type
   /// is 'Ty'.
-  void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit = false,
-                              SourceLocation DbgLoc = SourceLocation());
+  void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit = false);
   void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst);
   void EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst);
 
@@ -2537,12 +2521,10 @@ public:
 
   /// EmitComplexExprIntoLValue - Emit the given expression of complex
   /// type and place its result into the specified l-value.
-  void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit,
-                                 SourceLocation DbgLoc = SourceLocation());
+  void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit);
 
   /// EmitStoreOfComplex - Store a complex number into the specified l-value.
-  void EmitStoreOfComplex(ComplexPairTy V, LValue dest, bool isInit,
-                          SourceLocation DbgLoc = SourceLocation());
+  void EmitStoreOfComplex(ComplexPairTy V, LValue dest, bool isInit);
 
   /// EmitLoadOfComplex - Load a complex number from the specified l-value.
   ComplexPairTy EmitLoadOfComplex(LValue src, SourceLocation loc);