Add support for DW_TAG_thrown_type.

For Swift we would like to be able to encode the error types that a
function may throw, so the debugger can display them alongside the
function's return value when finish-ing a function.

DWARF defines DW_TAG_thrown_type (intended to be used for C++ throw()
declarations) that is a perfect fit for this purpose. This patch wires
up support for DW_TAG_thrown_type in LLVM by adding a list of thrown
types to DISubprogram.

To offset the cost of the extra pointer, there is a follow-up patch
that turns DISubprogram into a variable-length node.

rdar://problem/29481673

Differential Revision: https://reviews.llvm.org/D32559

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301489 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/DIBuilder.h

@@ -577,15 +577,14 @@ namespace llvm {
     ///                      These flags are used to emit dwarf attributes.
     /// \param isOptimized   True if optimization is ON.
     /// \param TParams       Function template parameters.
-    DISubprogram *createFunction(DIScope *Scope, StringRef Name,
-                                 StringRef LinkageName, DIFile *File,
-                                 unsigned LineNo, DISubroutineType *Ty,
-                                 bool isLocalToUnit, bool isDefinition,
-                                 unsigned ScopeLine,
-                                 DINode::DIFlags Flags = DINode::FlagZero,
-                                 bool isOptimized = false,
-                                 DITemplateParameterArray TParams = nullptr,
-                                 DISubprogram *Decl = nullptr);
+    /// \param ThrownTypes   Exception types this function may throw.
+    DISubprogram *createFunction(
+        DIScope *Scope, StringRef Name, StringRef LinkageName, DIFile *File,
+        unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
+        bool isDefinition, unsigned ScopeLine,
+        DINode::DIFlags Flags = DINode::FlagZero, bool isOptimized = false,
+        DITemplateParameterArray TParams = nullptr,
+        DISubprogram *Decl = nullptr, DITypeArray ThrownTypes = nullptr);
 
     /// Identical to createFunction,
     /// except that the resulting DbgNode is meant to be RAUWed.
@@ -595,7 +594,7 @@ namespace llvm {
         bool isDefinition, unsigned ScopeLine,
         DINode::DIFlags Flags = DINode::FlagZero, bool isOptimized = false,
         DITemplateParameterArray TParams = nullptr,
-        DISubprogram *Decl = nullptr);
+        DISubprogram *Decl = nullptr, DITypeArray ThrownTypes = nullptr);
 
     /// Create a new descriptor for the specified C++ method.
     /// See comments in \a DISubprogram* for descriptions of these fields.
@@ -619,13 +618,15 @@ namespace llvm {
     ///                      This flags are used to emit dwarf attributes.
     /// \param isOptimized   True if optimization is ON.
     /// \param TParams       Function template parameters.
+    /// \param ThrownTypes   Exception types this function may throw.
     DISubprogram *createMethod(
         DIScope *Scope, StringRef Name, StringRef LinkageName, DIFile *File,
         unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
         bool isDefinition, unsigned Virtuality = 0, unsigned VTableIndex = 0,
         int ThisAdjustment = 0, DIType *VTableHolder = nullptr,
         DINode::DIFlags Flags = DINode::FlagZero, bool isOptimized = false,
-        DITemplateParameterArray TParams = nullptr);
+        DITemplateParameterArray TParams = nullptr,
+        DITypeArray ThrownTypes = nullptr);
 
     /// This creates new descriptor for a namespace with the specified
     /// parent scope.

include/llvm/IR/DebugInfoMetadata.h

@@ -1509,14 +1509,14 @@ class DISubprogram : public DILocalScope {
           unsigned VirtualIndex, int ThisAdjustment, DIFlags Flags,
           bool IsOptimized, DICompileUnit *Unit,
           DITemplateParameterArray TemplateParams, DISubprogram *Declaration,
-          DILocalVariableArray Variables, StorageType Storage,
-          bool ShouldCreate = true) {
+          DILocalVariableArray Variables, DITypeArray ThrownTypes,
+          StorageType Storage, bool ShouldCreate = true) {
     return getImpl(Context, Scope, getCanonicalMDString(Context, Name),
                    getCanonicalMDString(Context, LinkageName), File, Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
                    Unit, TemplateParams.get(), Declaration, Variables.get(),
-                   Storage, ShouldCreate);
+                   ThrownTypes.get(), Storage, ShouldCreate);
   }
   static DISubprogram *
   getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
@@ -1525,15 +1525,16 @@ class DISubprogram : public DILocalScope {
           Metadata *ContainingType, unsigned Virtuality, unsigned VirtualIndex,
           int ThisAdjustment, DIFlags Flags, bool IsOptimized, Metadata *Unit,
           Metadata *TemplateParams, Metadata *Declaration, Metadata *Variables,
-          StorageType Storage, bool ShouldCreate = true);
+          Metadata *ThrownTypes, StorageType Storage, bool ShouldCreate = true);
 
   TempDISubprogram cloneImpl() const {
-    return getTemporary(
-        getContext(), getScope(), getName(), getLinkageName(), getFile(),
-        getLine(), getType(), isLocalToUnit(), isDefinition(), getScopeLine(),
-        getContainingType(), getVirtuality(), getVirtualIndex(),
-        getThisAdjustment(), getFlags(), isOptimized(), getUnit(),
-        getTemplateParams(), getDeclaration(), getVariables());
+    return getTemporary(getContext(), getScope(), getName(), getLinkageName(),
+                        getFile(), getLine(), getType(), isLocalToUnit(),
+                        isDefinition(), getScopeLine(), getContainingType(),
+                        getVirtuality(), getVirtualIndex(), getThisAdjustment(),
+                        getFlags(), isOptimized(), getUnit(),
+                        getTemplateParams(), getDeclaration(), getVariables(),
+                        getThrownTypes());
   }
 
 public:
@@ -1546,11 +1547,12 @@ public:
                      bool IsOptimized, DICompileUnit *Unit,
                      DITemplateParameterArray TemplateParams = nullptr,
                      DISubprogram *Declaration = nullptr,
-                     DILocalVariableArray Variables = nullptr),
+                     DILocalVariableArray Variables = nullptr,
+                     DITypeArray ThrownTypes = nullptr),
                     (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
                      IsDefinition, ScopeLine, ContainingType, Virtuality,
                      VirtualIndex, ThisAdjustment, Flags, IsOptimized, Unit,
-                     TemplateParams, Declaration, Variables))
+                     TemplateParams, Declaration, Variables, ThrownTypes))
   DEFINE_MDNODE_GET(
       DISubprogram,
       (Metadata * Scope, MDString *Name, MDString *LinkageName, Metadata *File,
@@ -1558,10 +1560,12 @@ public:
        unsigned ScopeLine, Metadata *ContainingType, unsigned Virtuality,
        unsigned VirtualIndex, int ThisAdjustment, DIFlags Flags,
        bool IsOptimized, Metadata *Unit, Metadata *TemplateParams = nullptr,
-       Metadata *Declaration = nullptr, Metadata *Variables = nullptr),
+       Metadata *Declaration = nullptr, Metadata *Variables = nullptr,
+       Metadata *ThrownTypes = nullptr),
       (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit, IsDefinition,
        ScopeLine, ContainingType, Virtuality, VirtualIndex, ThisAdjustment,
-       Flags, IsOptimized, Unit, TemplateParams, Declaration, Variables))
+       Flags, IsOptimized, Unit, TemplateParams, Declaration, Variables,
+       ThrownTypes))
 
   TempDISubprogram clone() const { return cloneImpl(); }
 
@@ -1626,9 +1630,7 @@ public:
   DICompileUnit *getUnit() const {
     return cast_or_null<DICompileUnit>(getRawUnit());
   }
-  void replaceUnit(DICompileUnit *CU) {
-    replaceOperandWith(7, CU);
-  }
+  void replaceUnit(DICompileUnit *CU) { replaceOperandWith(7, CU); }
   DITemplateParameterArray getTemplateParams() const {
     return cast_or_null<MDTuple>(getRawTemplateParams());
   }
@@ -1638,6 +1640,9 @@ public:
   DILocalVariableArray getVariables() const {
     return cast_or_null<MDTuple>(getRawVariables());
   }
+  DITypeArray getThrownTypes() const {
+    return cast_or_null<MDTuple>(getRawThrownTypes());
+  }
 
   Metadata *getRawScope() const { return getOperand(1); }
   Metadata *getRawType() const { return getOperand(5); }
@@ -1646,6 +1651,7 @@ public:
   Metadata *getRawTemplateParams() const { return getOperand(8); }
   Metadata *getRawDeclaration() const { return getOperand(9); }
   Metadata *getRawVariables() const { return getOperand(10); }
+  Metadata *getRawThrownTypes() const { return getOperand(11); }
 
   /// Check if this subprogram describes the given function.
   ///

lib/AsmParser/LLParser.cpp

@@ -4071,7 +4071,7 @@ bool LLParser::ParseDICompileUnit(MDNode *&Result, bool IsDistinct) {
 ///                     virtuality: DW_VIRTUALTIY_pure_virtual,
 ///                     virtualIndex: 10, thisAdjustment: 4, flags: 11,
 ///                     isOptimized: false, templateParams: !4, declaration: !5,
-///                     variables: !6)
+///                     variables: !6, thrownTypes: !7)
 bool LLParser::ParseDISubprogram(MDNode *&Result, bool IsDistinct) {
   auto Loc = Lex.getLoc();
 #define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
@@ -4093,7 +4093,8 @@ bool LLParser::ParseDISubprogram(MDNode *&Result, bool IsDistinct) {
   OPTIONAL(unit, MDField, );                                                   \
   OPTIONAL(templateParams, MDField, );                                         \
   OPTIONAL(declaration, MDField, );                                            \
-  OPTIONAL(variables, MDField, );
+  OPTIONAL(variables, MDField, );                                              \
+  OPTIONAL(thrownTypes, MDField, );
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
@@ -4103,12 +4104,12 @@ bool LLParser::ParseDISubprogram(MDNode *&Result, bool IsDistinct) {
         "missing 'distinct', required for !DISubprogram when 'isDefinition'");
 
   Result = GET_OR_DISTINCT(
-      DISubprogram, (Context, scope.Val, name.Val, linkageName.Val, file.Val,
-                     line.Val, type.Val, isLocal.Val, isDefinition.Val,
-                     scopeLine.Val, containingType.Val, virtuality.Val,
-                     virtualIndex.Val, thisAdjustment.Val, flags.Val,
-                     isOptimized.Val, unit.Val, templateParams.Val,
-                     declaration.Val, variables.Val));
+      DISubprogram,
+      (Context, scope.Val, name.Val, linkageName.Val, file.Val, line.Val,
+       type.Val, isLocal.Val, isDefinition.Val, scopeLine.Val,
+       containingType.Val, virtuality.Val, virtualIndex.Val, thisAdjustment.Val,
+       flags.Val, isOptimized.Val, unit.Val, templateParams.Val,
+       declaration.Val, variables.Val, thrownTypes.Val));
   return false;
 }
 

lib/Bitcode/Reader/MetadataLoader.cpp

@@ -1298,7 +1298,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     break;
   }
   case bitc::METADATA_SUBPROGRAM: {
-    if (Record.size() < 18 || Record.size() > 20)
+    if (Record.size() < 18 || Record.size() > 21)
       return error("Invalid record");
 
     IsDistinct =
@@ -1314,29 +1314,31 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     unsigned Offset = Record.size() >= 19 ? 1 : 0;
     bool HasFn = Offset && !HasUnit;
     bool HasThisAdj = Record.size() >= 20;
+    bool HasThrownTypes = Record.size() >= 21;
     DISubprogram *SP = GET_OR_DISTINCT(
-        DISubprogram, (Context,
-                       getDITypeRefOrNull(Record[1]),          // scope
-                       getMDString(Record[2]),                 // name
-                       getMDString(Record[3]),                 // linkageName
-                       getMDOrNull(Record[4]),                 // file
-                       Record[5],                              // line
-                       getMDOrNull(Record[6]),                 // type
-                       Record[7],                              // isLocal
-                       Record[8],                              // isDefinition
-                       Record[9],                              // scopeLine
-                       getDITypeRefOrNull(Record[10]),         // containingType
-                       Record[11],                             // virtuality
-                       Record[12],                             // virtualIndex
-                       HasThisAdj ? Record[19] : 0,            // thisAdjustment
-                       static_cast<DINode::DIFlags>(Record[13] // flags
-                                                    ),
-                       Record[14],                       // isOptimized
-                       HasUnit ? CUorFn : nullptr,       // unit
-                       getMDOrNull(Record[15 + Offset]), // templateParams
-                       getMDOrNull(Record[16 + Offset]), // declaration
-                       getMDOrNull(Record[17 + Offset])  // variables
-                       ));
+        DISubprogram,
+        (Context,
+         getDITypeRefOrNull(Record[1]),                     // scope
+         getMDString(Record[2]),                            // name
+         getMDString(Record[3]),                            // linkageName
+         getMDOrNull(Record[4]),                            // file
+         Record[5],                                         // line
+         getMDOrNull(Record[6]),                            // type
+         Record[7],                                         // isLocal
+         Record[8],                                         // isDefinition
+         Record[9],                                         // scopeLine
+         getDITypeRefOrNull(Record[10]),                    // containingType
+         Record[11],                                        // virtuality
+         Record[12],                                        // virtualIndex
+         HasThisAdj ? Record[19] : 0,                       // thisAdjustment
+         static_cast<DINode::DIFlags>(Record[13]),          // flags
+         Record[14],                                        // isOptimized
+         HasUnit ? CUorFn : nullptr,                        // unit
+         getMDOrNull(Record[15 + Offset]),                  // templateParams
+         getMDOrNull(Record[16 + Offset]),                  // declaration
+         getMDOrNull(Record[17 + Offset]),                  // variables
+         HasThrownTypes ? getMDOrNull(Record[20]) : nullptr // thrownTypes
+         ));
     MetadataList.assignValue(SP, NextMetadataNo);
     NextMetadataNo++;
 

lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -1608,6 +1608,7 @@ void ModuleBitcodeWriter::writeDISubprogram(const DISubprogram *N,
   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
   Record.push_back(N->getThisAdjustment());
+  Record.push_back(VE.getMetadataOrNullID(N->getThrownTypes().get()));
 
   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
   Record.clear();

lib/CodeGen/AsmPrinter/DwarfUnit.cpp

@@ -662,6 +662,14 @@ void DwarfUnit::addTemplateParams(DIE &Buffer, DINodeArray TParams) {
   }
 }
 
+/// Add thrown types.
+void DwarfUnit::addThrownTypes(DIE &Die, DINodeArray ThrownTypes) {
+  for (const auto *Ty : ThrownTypes) {
+    DIE &TT = createAndAddDIE(dwarf::DW_TAG_thrown_type, Die);
+    addType(TT, cast<DIType>(Ty));
+  }
+}
+
 DIE *DwarfUnit::getOrCreateContextDIE(const DIScope *Context) {
   if (!Context || isa<DIFile>(Context))
     return &getUnitDie();
@@ -1249,6 +1257,8 @@ void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
     constructSubprogramArguments(SPDie, Args);
   }
 
+  addThrownTypes(SPDie, SP->getThrownTypes());
+
   if (SP->isArtificial())
     addFlag(SPDie, dwarf::DW_AT_artificial);
 

lib/CodeGen/AsmPrinter/DwarfUnit.h

@@ -230,6 +230,9 @@ public:
   /// Add template parameters in buffer.
   void addTemplateParams(DIE &Buffer, DINodeArray TParams);
 
+  /// Add thrown types.
+  void addThrownTypes(DIE &Die, DINodeArray ThrownTypes);
+
   // FIXME: Should be reformulated in terms of addComplexAddress.
   /// Start with the address based on the location provided, and generate the
   /// DWARF information necessary to find the actual Block variable (navigating

lib/IR/AsmWriter.cpp

@@ -1719,6 +1719,7 @@ static void writeDISubprogram(raw_ostream &Out, const DISubprogram *N,
   Printer.printMetadata("templateParams", N->getRawTemplateParams());
   Printer.printMetadata("declaration", N->getRawDeclaration());
   Printer.printMetadata("variables", N->getRawVariables());
+  Printer.printMetadata("thrownTypes", N->getRawThrownTypes());
   Out << ")";
 }
 

lib/IR/DIBuilder.cpp

@@ -676,13 +676,14 @@ DISubprogram *DIBuilder::createFunction(
     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
     bool isDefinition, unsigned ScopeLine, DINode::DIFlags Flags,
-    bool isOptimized, DITemplateParameterArray TParams, DISubprogram *Decl) {
+    bool isOptimized, DITemplateParameterArray TParams, DISubprogram *Decl,
+    DITypeArray ThrownTypes) {
   auto *Node = getSubprogram(
       /* IsDistinct = */ isDefinition, VMContext,
       getNonCompileUnitScope(Context), Name, LinkageName, File, LineNo, Ty,
       isLocalToUnit, isDefinition, ScopeLine, nullptr, 0, 0, 0, Flags,
       isOptimized, isDefinition ? CUNode : nullptr, TParams, Decl,
-      MDTuple::getTemporary(VMContext, None).release());
+      MDTuple::getTemporary(VMContext, None).release(), ThrownTypes);
 
   if (isDefinition)
     AllSubprograms.push_back(Node);
@@ -694,23 +695,22 @@ DISubprogram *DIBuilder::createTempFunctionFwdDecl(
     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
     unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
     bool isDefinition, unsigned ScopeLine, DINode::DIFlags Flags,
-    bool isOptimized, DITemplateParameterArray TParams, DISubprogram *Decl) {
+    bool isOptimized, DITemplateParameterArray TParams, DISubprogram *Decl,
+    DITypeArray ThrownTypes) {
   return DISubprogram::getTemporary(
              VMContext, getNonCompileUnitScope(Context), Name, LinkageName,
              File, LineNo, Ty, isLocalToUnit, isDefinition, ScopeLine, nullptr,
              0, 0, 0, Flags, isOptimized, isDefinition ? CUNode : nullptr,
-             TParams, Decl, nullptr)
+             TParams, Decl, nullptr, ThrownTypes)
       .release();
 }
 
-DISubprogram *DIBuilder::createMethod(DIScope *Context, StringRef Name,
-                                      StringRef LinkageName, DIFile *F,
-                                      unsigned LineNo, DISubroutineType *Ty,
-                                      bool isLocalToUnit, bool isDefinition,
-                                      unsigned VK, unsigned VIndex,
-                                      int ThisAdjustment, DIType *VTableHolder,
-                                      DINode::DIFlags Flags, bool isOptimized,
-                                      DITemplateParameterArray TParams) {
+DISubprogram *DIBuilder::createMethod(
+    DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
+    unsigned LineNo, DISubroutineType *Ty, bool isLocalToUnit,
+    bool isDefinition, unsigned VK, unsigned VIndex, int ThisAdjustment,
+    DIType *VTableHolder, DINode::DIFlags Flags, bool isOptimized,
+    DITemplateParameterArray TParams, DITypeArray ThrownTypes) {
   assert(getNonCompileUnitScope(Context) &&
          "Methods should have both a Context and a context that isn't "
          "the compile unit.");
@@ -719,7 +719,7 @@ DISubprogram *DIBuilder::createMethod(DIScope *Context, StringRef Name,
       /* IsDistinct = */ isDefinition, VMContext, cast<DIScope>(Context), Name,
       LinkageName, F, LineNo, Ty, isLocalToUnit, isDefinition, LineNo,
       VTableHolder, VK, VIndex, ThisAdjustment, Flags, isOptimized,
-      isDefinition ? CUNode : nullptr, TParams, nullptr, nullptr);
+      isDefinition ? CUNode : nullptr, TParams, nullptr, nullptr, ThrownTypes);
 
   if (isDefinition)
     AllSubprograms.push_back(SP);

lib/IR/DebugInfoMetadata.cpp

@@ -441,17 +441,17 @@ DISubprogram *DISubprogram::getImpl(
     Metadata *ContainingType, unsigned Virtuality, unsigned VirtualIndex,
     int ThisAdjustment, DIFlags Flags, bool IsOptimized, Metadata *Unit,
     Metadata *TemplateParams, Metadata *Declaration, Metadata *Variables,
-    StorageType Storage, bool ShouldCreate) {
+    Metadata *ThrownTypes, StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
   assert(isCanonical(LinkageName) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(
-      DISubprogram,
-      (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit, IsDefinition,
-       ScopeLine, ContainingType, Virtuality, VirtualIndex, ThisAdjustment,
-       Flags, IsOptimized, Unit, TemplateParams, Declaration, Variables));
+      DISubprogram, (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
+                     IsDefinition, ScopeLine, ContainingType, Virtuality,
+                     VirtualIndex, ThisAdjustment, Flags, IsOptimized, Unit,
+                     TemplateParams, Declaration, Variables, ThrownTypes));
   Metadata *Ops[] = {File,           Scope,       Name,           Name,
                      LinkageName,    Type,        ContainingType, Unit,
-                     TemplateParams, Declaration, Variables};
+                     TemplateParams, Declaration, Variables,      ThrownTypes};
   DEFINE_GETIMPL_STORE(DISubprogram, (Line, ScopeLine, Virtuality, VirtualIndex,
                                       ThisAdjustment, Flags, IsLocalToUnit,
                                       IsDefinition, IsOptimized),

lib/IR/LLVMContextImpl.h

@@ -552,6 +552,7 @@ template <> struct MDNodeKeyImpl<DISubprogram> {
   Metadata *TemplateParams;
   Metadata *Declaration;
   Metadata *Variables;
+  Metadata *ThrownTypes;
 
   MDNodeKeyImpl(Metadata *Scope, MDString *Name, MDString *LinkageName,
                 Metadata *File, unsigned Line, Metadata *Type,
@@ -559,7 +560,8 @@ template <> struct MDNodeKeyImpl<DISubprogram> {
                 Metadata *ContainingType, unsigned Virtuality,
                 unsigned VirtualIndex, int ThisAdjustment, unsigned Flags,
                 bool IsOptimized, Metadata *Unit, Metadata *TemplateParams,
-                Metadata *Declaration, Metadata *Variables)
+                Metadata *Declaration, Metadata *Variables,
+                Metadata *ThrownTypes)
       : Scope(Scope), Name(Name), LinkageName(LinkageName), File(File),
         Line(Line), Type(Type), IsLocalToUnit(IsLocalToUnit),
         IsDefinition(IsDefinition), ScopeLine(ScopeLine),
@@ -567,7 +569,7 @@ template <> struct MDNodeKeyImpl<DISubprogram> {
         VirtualIndex(VirtualIndex), ThisAdjustment(ThisAdjustment),
         Flags(Flags), IsOptimized(IsOptimized), Unit(Unit),
         TemplateParams(TemplateParams), Declaration(Declaration),
-        Variables(Variables) {}
+        Variables(Variables), ThrownTypes(ThrownTypes) {}
   MDNodeKeyImpl(const DISubprogram *N)
       : Scope(N->getRawScope()), Name(N->getRawName()),
         LinkageName(N->getRawLinkageName()), File(N->getRawFile()),
@@ -578,7 +580,8 @@ template <> struct MDNodeKeyImpl<DISubprogram> {
         ThisAdjustment(N->getThisAdjustment()), Flags(N->getFlags()),
         IsOptimized(N->isOptimized()), Unit(N->getRawUnit()),
         TemplateParams(N->getRawTemplateParams()),
-        Declaration(N->getRawDeclaration()), Variables(N->getRawVariables()) {}
+        Declaration(N->getRawDeclaration()), Variables(N->getRawVariables()),
+        ThrownTypes(N->getRawThrownTypes()) {}
 
   bool isKeyOf(const DISubprogram *RHS) const {
     return Scope == RHS->getRawScope() && Name == RHS->getRawName() &&
@@ -595,7 +598,8 @@ template <> struct MDNodeKeyImpl<DISubprogram> {
            Unit == RHS->getUnit() &&
            TemplateParams == RHS->getRawTemplateParams() &&
            Declaration == RHS->getRawDeclaration() &&
-           Variables == RHS->getRawVariables();
+           Variables == RHS->getRawVariables() &&
+           ThrownTypes == RHS->getRawThrownTypes();
   }
   unsigned getHashValue() const {
     // If this is a declaration inside an ODR type, only hash the type and the

lib/IR/Verifier.cpp

@@ -1050,6 +1050,14 @@ void Verifier::visitDISubprogram(const DISubprogram &N) {
     // Subprogram declarations (part of the type hierarchy).
     AssertDI(!Unit, "subprogram declarations must not have a compile unit", &N);
   }
+
+  if (auto *RawThrownTypes = N.getRawThrownTypes()) {
+    auto *ThrownTypes = dyn_cast<MDTuple>(RawThrownTypes);
+    AssertDI(ThrownTypes, "invalid thrown types list", &N, RawThrownTypes);
+    for (Metadata *Op : ThrownTypes->operands())
+      AssertDI(Op && isa<DIType>(Op), "invalid thrown type", &N, ThrownTypes,
+               Op);
+  }
 }
 
 void Verifier::visitDILexicalBlockBase(const DILexicalBlockBase &N) {

test/Assembler/disubprogram.ll

@@ -6,8 +6,8 @@ define void @_Z3foov() !dbg !9 {
   ret void
 }
 
-; CHECK: !named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12}
-!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12}
+; CHECK: !named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13, !14}
+!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13, !14}
 
 !0 = !{null}
 !1 = distinct !DICompositeType(tag: DW_TAG_structure_type)
@@ -61,6 +61,14 @@ define void @_Z3foov() !dbg !9 {
                             unit: !8,
                             templateParams: !5, declaration: !9, variables: !6)
 
-!13 = !{i32 1, !"Debug Info Version", i32 3}
-!llvm.module.flags = !{!13}
+!13 = !{!4}
+; CHECK: !13 = !{!4}
+; CHECK: !14 = distinct !DISubprogram(name: "foo", scope: !1, file: !2, line: 1, type: !3, isLocal: true, isDefinition: true, scopeLine: 2, isOptimized: false, unit: !8, thrownTypes: !13)
+!14 = distinct !DISubprogram(name: "foo", scope: !1,
+                            file: !2, line: 1, type: !3, isLocal: true,
+                            isDefinition: true, scopeLine: 2, isOptimized: false,
+                            unit: !8, thrownTypes: !13)
+
+!15 = !{i32 1, !"Debug Info Version", i32 3}
+!llvm.module.flags = !{!15}
 !llvm.dbg.cu = !{!8}

test/DebugInfo/Generic/thrownTypes.ll

@@ -0,0 +1,38 @@
+; REQUIRES: object-emission
+
+; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+
+; CHECK: DW_TAG_subprogram
+; CHECK:   DW_AT_name {{.*}} "f"
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_TAG_thrown_type
+; CHECK-NEXT:   DW_AT_type {{.*}} {[[ERROR:.*]]}
+; CHECK-NOT: DW_TAG
+; CHECK:   DW_TAG_thrown_type
+; CHECK-NEXT:   DW_AT_type {{.*}} {[[ERROR2:.*]]}
+; CHECK: [[ERROR]]: DW_TAG_structure_type
+; CHECK-NEXT:   DW_AT_name {{.*}} "Error"
+; CHECK: [[ERROR2]]: DW_TAG_structure_type
+; CHECK-NEXT:   DW_AT_name {{.*}} "DifferentError"
+
+; Function Attrs: nounwind uwtable
+define void @f() #0 !dbg !5 {
+entry:
+  ret void, !dbg !11
+}
+
+attributes #0 = { nounwind uwtable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!8, !9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_Swift, producer: "swiftc", isOptimized: false, emissionKind: FullDebug, file: !1)
+!1 = !DIFile(filename: "f.swift", directory: "/")
+!3 = !DICompositeType(tag: DW_TAG_structure_type, name: "Error")
+!4 = !DICompositeType(tag: DW_TAG_structure_type, name: "DifferentError")
+!5 = distinct !DISubprogram(name: "f", line: 2, isLocal: false, isDefinition: true, unit: !0, scopeLine: 2, file: !1, scope: !1, type: !6, thrownTypes: !{!3, !4})
+!6 = !DISubroutineType(types: !7)
+!7 = !{null}
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 1, !"Debug Info Version", i32 3}
+!11 = !DILocation(line: 3, scope: !5)

test/Verifier/DISubprogram.ll

@@ -0,0 +1,22 @@
+; RUN: not opt -S <%s 2>&1| FileCheck %s
+
+define void @f() !dbg !14 {
+  ret void
+}
+
+!0 = !{null}
+!1 = distinct !DICompositeType(tag: DW_TAG_structure_type)
+!2 = !DIFile(filename: "path/to/file", directory: "/path/to/dir")
+!3 = !DISubroutineType(types: !0)
+!4 = distinct !DICompositeType(tag: DW_TAG_structure_type)
+!8 = distinct !DICompileUnit(language: DW_LANG_Swift, producer: "clang",
+                             file: !2, emissionKind: 2)
+; CHECK: invalid thrown type
+!13 = !{!14}
+!14 = distinct !DISubprogram(name: "f", scope: !1,
+                            file: !2, line: 1, type: !3, isLocal: true,
+                            isDefinition: true, scopeLine: 2,
+                            unit: !8, thrownTypes: !13)
+!15 = !{i32 1, !"Debug Info Version", i32 3}
+!llvm.module.flags = !{!15}
+!llvm.dbg.cu = !{!8}

unittests/IR/IRBuilderTest.cpp

@@ -356,6 +356,25 @@ TEST_F(IRBuilderTest, RAIIHelpersTest) {
   EXPECT_EQ(BB, Builder.GetInsertBlock());
 }
 
+TEST_F(IRBuilderTest, createFunction) {
+  IRBuilder<> Builder(BB);
+  DIBuilder DIB(*M);
+  auto File = DIB.createFile("error.swift", "/");
+  auto CU =
+      DIB.createCompileUnit(dwarf::DW_LANG_Swift, File, "swiftc", true, "", 0);
+  auto Type = DIB.createSubroutineType(DIB.getOrCreateTypeArray(None));
+  auto NoErr = DIB.createFunction(CU, "noerr", "", File, 1, Type, false, true, 1,
+                               DINode::FlagZero, true);
+  EXPECT_TRUE(!NoErr->getThrownTypes());
+  auto Int = DIB.createBasicType("Int", 64, dwarf::DW_ATE_signed);
+  auto Error = DIB.getOrCreateArray({Int});
+  auto Err =
+      DIB.createFunction(CU, "err", "", File, 1, Type, false, true, 1,
+      DINode::FlagZero, true, nullptr, nullptr, Error.get());
+  EXPECT_TRUE(Err->getThrownTypes().get() == Error.get());
+  DIB.finalize();
+}
+
 TEST_F(IRBuilderTest, DIBuilder) {
   IRBuilder<> Builder(BB);
   DIBuilder DIB(*M);

unittests/IR/MetadataTest.cpp

@@ -1512,13 +1512,14 @@ TEST_F(DISubprogramTest, get) {
   MDTuple *TemplateParams = getTuple();
   DISubprogram *Declaration = getSubprogram();
   MDTuple *Variables = getTuple();
+  MDTuple *ThrownTypes = getTuple();
   DICompileUnit *Unit = getUnit();
 
-  auto *N = DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                              Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                              ContainingType, Virtuality, VirtualIndex,
-                              ThisAdjustment, Flags, IsOptimized, Unit,
-                              TemplateParams, Declaration, Variables);
+  auto *N = DISubprogram::get(
+      Context, Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
+      IsDefinition, ScopeLine, ContainingType, Virtuality, VirtualIndex,
+      ThisAdjustment, Flags, IsOptimized, Unit, TemplateParams, Declaration,
+      Variables, ThrownTypes);
 
   EXPECT_EQ(dwarf::DW_TAG_subprogram, N->getTag());
   EXPECT_EQ(Scope, N->getScope());
@@ -1540,98 +1541,109 @@ TEST_F(DISubprogramTest, get) {
   EXPECT_EQ(TemplateParams, N->getTemplateParams().get());
   EXPECT_EQ(Declaration, N->getDeclaration());
   EXPECT_EQ(Variables, N->getVariables().get());
-  EXPECT_EQ(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+  EXPECT_EQ(ThrownTypes, N->getThrownTypes().get());
+  EXPECT_EQ(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
 
   EXPECT_NE(N, DISubprogram::get(
                    Context, getCompositeType(), Name, LinkageName, File, Line,
                    Type, IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, "other", LinkageName, File, Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, "other", File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, "other", File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, Name, LinkageName, getFile(), Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, Name, LinkageName, File, Line + 1, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N,
-            DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                              getSubroutineType(), IsLocalToUnit, IsDefinition,
-                              ScopeLine, ContainingType, Virtuality,
-                              VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                              Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, !IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, !IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 getSubroutineType(), IsLocalToUnit,
+                                 IsDefinition, ScopeLine, ContainingType,
+                                 Virtuality, VirtualIndex, ThisAdjustment,
+                                 Flags, IsOptimized, Unit, TemplateParams,
+                                 Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   !IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, !IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(
                    Context, Scope, Name, LinkageName, File, Line, Type,
                    IsLocalToUnit, IsDefinition, ScopeLine + 1, ContainingType,
                    Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
-                   Unit, TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 getCompositeType(), Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, getCompositeType(),
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality + 1, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex + 1,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, !IsOptimized, Unit,
-                                 TemplateParams, Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, nullptr,
-                                 TemplateParams, Declaration, Variables));
-  EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
-                                 Type, IsLocalToUnit, IsDefinition, ScopeLine,
-                                 ContainingType, Virtuality, VirtualIndex,
-                                 ThisAdjustment, Flags, IsOptimized, Unit,
-                                 getTuple(), Declaration, Variables));
+                                 TemplateParams, Declaration, Variables,
+                                 ThrownTypes));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, getTuple(), Declaration, Variables, ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
-                                 TemplateParams, getSubprogram(), Variables));
+                                 TemplateParams, getSubprogram(), Variables,
+                                 ThrownTypes));
   EXPECT_NE(N, DISubprogram::get(Context, Scope, Name, LinkageName, File, Line,
                                  Type, IsLocalToUnit, IsDefinition, ScopeLine,
                                  ContainingType, Virtuality, VirtualIndex,
                                  ThisAdjustment, Flags, IsOptimized, Unit,
                                  TemplateParams, Declaration, getTuple()));
+  EXPECT_NE(N, DISubprogram::get(
+                   Context, Scope, Name, LinkageName, File, Line, Type,
+                   IsLocalToUnit, IsDefinition, ScopeLine, ContainingType,
+                   Virtuality, VirtualIndex, ThisAdjustment, Flags, IsOptimized,
+                   Unit, TemplateParams, Declaration, Variables, getTuple()));
 
   TempDISubprogram Temp = N->clone();
   EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));