[DebugInfo] Emit debug info for witness tables

include/swift/AST/Types.h

@@ -7311,7 +7311,10 @@ class GenericTypeParamType : public SubstitutableType,
 
   /// Get the name of the generic type parameter.
   Identifier getName() const;
-
+
+  /// Get the canonical <tau>_n_n name;
+  Identifier getCanonicalName() const;
+
   /// The depth of this generic type parameter, i.e., the number of outer
   /// levels of generic parameter lists that enclose this type parameter.
   ///

lib/AST/Type.cpp

@@ -2124,8 +2124,10 @@ Identifier GenericTypeParamType::getName() const {
   if (!isCanonical())
     return Name;
 
-  // Otherwise, we're canonical. Produce an anonymous '<tau>_n_n' name.
+  return getCanonicalName();
+}
 
+Identifier GenericTypeParamType::getCanonicalName() const {
   // getASTContext() doesn't actually mutate an already-canonical type.
   auto &C = const_cast<GenericTypeParamType*>(this)->getASTContext();
   auto &names = C.CanonicalGenericTypeParamTypeNames;

lib/IRGen/IRGenDebugInfo.cpp

@@ -279,8 +279,16 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
                                      DebugTypeInfo DebugType,
                                      bool IsLocalToUnit,
                                      std::optional<SILLocation> Loc);
+
+  void emitArtificialVariable(IRGenFunction &IGF, llvm::Value *Metadata,
+                              StringRef Name, StringRef Identifier);
+
   void emitTypeMetadata(IRGenFunction &IGF, llvm::Value *Metadata,
-                        unsigned Depth, unsigned Index, StringRef Name);
+                        GenericTypeParamType *Type);
+
+  void emitWitnessTable(IRGenFunction &IGF, llvm::Value *Metadata,
+                        StringRef Name, ProtocolDecl *protocol);
+
   void emitPackCountParameter(IRGenFunction &IGF, llvm::Value *Metadata,
                               SILDebugVariable VarInfo);
 
@@ -3904,9 +3912,10 @@ void IRGenDebugInfoImpl::emitGlobalVariableDeclaration(
     Var->addDebugInfo(GV);
 }
 
-void IRGenDebugInfoImpl::emitTypeMetadata(IRGenFunction &IGF,
-                                          llvm::Value *Metadata, unsigned Depth,
-                                          unsigned Index, StringRef Name) {
+void IRGenDebugInfoImpl::emitArtificialVariable(IRGenFunction &IGF,
+                                                llvm::Value *Metadata,
+                                                StringRef Name,
+                                                StringRef Identifier) {
   if (Opts.DebugInfoLevel <= IRGenDebugInfoLevel::LineTables)
     return;
 
@@ -3915,23 +3924,44 @@ void IRGenDebugInfoImpl::emitTypeMetadata(IRGenFunction &IGF,
   if (!DS || DS->getInlinedFunction()->isTransparent())
     return;
 
-  llvm::SmallString<8> Buf;
-  static const char *Tau = SWIFT_UTF8("\u03C4");
-  llvm::raw_svector_ostream OS(Buf);
-  OS << '$' << Tau << '_' << Depth << '_' << Index;
-  uint64_t PtrWidthInBits = CI.getTargetInfo().getPointerWidth(clang::LangAS::Default);
+  uint64_t PtrWidthInBits =
+      CI.getTargetInfo().getPointerWidth(clang::LangAS::Default);
   assert(PtrWidthInBits % 8 == 0);
   auto DbgTy = DebugTypeInfo::getTypeMetadata(
       getMetadataType(Name)->getDeclaredInterfaceType().getPointer(),
       Size(PtrWidthInBits / 8),
       Alignment(CI.getTargetInfo().getPointerAlign(clang::LangAS::Default)));
-  emitVariableDeclaration(IGF.Builder, Metadata, DbgTy, IGF.getDebugScope(),
-                          {}, {OS.str().str(), 0, false},
-                          // swift.type is already a pointer type,
-                          // having a shadow copy doesn't add another
-                          // layer of indirection.
-                          IGF.isAsync() ? CoroDirectValue : DirectValue,
-                          ArtificialValue);
+  emitVariableDeclaration(
+      IGF.Builder, Metadata, DbgTy, IGF.getDebugScope(), {},
+      {Identifier, 0, false}, // swift.type is already a pointer type,
+                              // having a shadow copy doesn't add another
+                              // layer of indirection.
+      IGF.isAsync() ? CoroDirectValue : DirectValue, ArtificialValue);
+}
+
+void IRGenDebugInfoImpl::emitTypeMetadata(IRGenFunction &IGF,
+                                          llvm::Value *Metadata,
+                                          GenericTypeParamType *Type) {
+  llvm::SmallString<8> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+  OS << "$" << Type->getCanonicalName().str();
+  auto Name = Type->getName().str();
+
+  emitArtificialVariable(IGF, Metadata, Name, OS.str());
+}
+
+void IRGenDebugInfoImpl::emitWitnessTable(IRGenFunction &IGF,
+                                          llvm::Value *Metadata, StringRef Name,
+                                          ProtocolDecl *protocol) {
+  llvm::SmallString<32> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+  DebugTypeInfo DbgTy(protocol->getDeclaredType());
+  auto MangledName = getMangledName(DbgTy).Canonical;
+  OS << "$WT" << Name << "$$" << MangledName;;
+  // Make sure this ID lives long enough.
+  auto Id = IGF.getSwiftModule()->getASTContext().getIdentifier(OS.str());
+
+  emitArtificialVariable(IGF, Metadata, Name, Id.str());
 }
 
 void IRGenDebugInfoImpl::emitPackCountParameter(IRGenFunction &IGF,
@@ -4070,10 +4100,15 @@ void IRGenDebugInfo::emitGlobalVariableDeclaration(
 }
 
 void IRGenDebugInfo::emitTypeMetadata(IRGenFunction &IGF, llvm::Value *Metadata,
-                                      unsigned Depth, unsigned Index,
-                                      StringRef Name) {
+                                      GenericTypeParamType *Type) {
   static_cast<IRGenDebugInfoImpl *>(this)->emitTypeMetadata(IGF, Metadata,
-                                                            Depth, Index, Name);
+                                                            Type);
+}
+
+void IRGenDebugInfo::emitWitnessTable(IRGenFunction &IGF, llvm::Value *Metadata,
+                                      StringRef Name, ProtocolDecl *protocol) {
+  static_cast<IRGenDebugInfoImpl *>(this)->emitWitnessTable(IGF, Metadata, Name,
+                                                            protocol);
 }
 
 void IRGenDebugInfo::emitPackCountParameter(IRGenFunction &IGF,

lib/IRGen/IRGenDebugInfo.h

@@ -186,7 +186,11 @@ class IRGenDebugInfo {
 
   /// Emit debug metadata for type metadata (for generic types). So meta.
   void emitTypeMetadata(IRGenFunction &IGF, llvm::Value *Metadata,
-                        unsigned Depth, unsigned Index, StringRef Name);
+                        GenericTypeParamType *Type);
+
+  /// Emit debug metadata for a (protocol) witness table.
+  void emitWitnessTable(IRGenFunction &IGF, llvm::Value *Metadata,
+                        StringRef Name, ProtocolDecl *protocol);
 
   /// Emit debug info for the IR function parameter holding the size of one or
   /// more parameter / type packs.

lib/IRGen/IRGenSIL.cpp

@@ -1168,8 +1168,42 @@ class IRGenSILFunction :
           emitPackCountDebugVariable(Shape);
         }
       });
+
+    if (auto *BGT = llvm::dyn_cast<BoundGenericType>(Ty)) {
+      auto Decl = BGT->getDecl();
+      auto GE = Decl->getGenericEnvironment();
+      auto Requirements = BGT->getDecl()
+                              ->getGenericEnvironment()
+                              ->getGenericSignature()
+                              .getRequirements();
+      for (auto Requirement : Requirements) {
+        if (Requirement.getKind() == RequirementKind::Conformance) {
+          auto ProtocolDecl = Requirement.getProtocolDecl();
+          auto ConformingType = Requirement.getFirstType();
+          Type Archetype;
+          if (auto GTPT = llvm::dyn_cast<GenericTypeParamType>(
+                  ConformingType.getPointer()))
+            Archetype = GE->mapTypeIntoContext(GTPT);
+          else if (auto DMT = llvm::dyn_cast<DependentMemberType>(
+                       ConformingType.getPointer()))
+            Archetype = GE->mapTypeIntoContext(DMT);
+
+          if (Lowering::TypeConverter::protocolRequiresWitnessTable(
+                  ProtocolDecl) &&
+              tryGetLocalTypeData(
+                  Archetype->getCanonicalType(),
+                  LocalTypeDataKind::forAbstractProtocolWitnessTable(
+                      ProtocolDecl))) {
+            auto Conformance =
+                ProtocolConformanceRef::forAbstract(Archetype, ProtocolDecl);
+
+            emitWitnessTableRef(*this, Archetype->getCanonicalType(),
+                                Conformance);
+          }
+        }
+      }
+    }
   }
-
   /// Emit debug info for a function argument or a local variable.
   template <typename StorageType>
   void emitDebugVariableDeclaration(

lib/IRGen/LocalTypeData.cpp

@@ -408,26 +408,59 @@ static void maybeEmitDebugInfoForLocalTypeData(IRGenFunction &IGF,
   // functions that were inlined into transparent functions. Correct would be to
   // check which instruction requests the type metadata and see whether its
   // inlined function is transparent.
-  auto * DS = IGF.getDebugScope();
+  auto *DS = IGF.getDebugScope();
   if (DS && DS->getInlinedFunction() &&
       DS->getInlinedFunction()->isTransparent())
     return;
-
-  // Only for formal type metadata.
-  if (key.Kind != LocalTypeDataKind::forFormalTypeMetadata())
+  // For formal type metadata and witness tables.
+  ProtocolDecl *proto = nullptr;
+
+  if (key.Kind.isAbstractProtocolConformance())
+    proto = key.Kind.getAbstractProtocolConformance();
+  else if (key.Kind.isConcreteProtocolConformance())
+    proto = key.Kind.getConcreteProtocolConformance()->getProtocol();
+  else if (key.Kind != LocalTypeDataKind::forFormalTypeMetadata())
     return;
 
   // Only for archetypes, and not for opened/opaque archetypes.
   auto type = dyn_cast<ArchetypeType>(key.Type);
   if (!type)
     return;
-  if (!type->isRoot())
+  if (!type->isRoot() && !proto)
     return;
   if (!isa<PrimaryArchetypeType>(type) && !isa<PackArchetypeType>(type))
     return;
 
-  auto *typeParam = type->getInterfaceType()->castTo<GenericTypeParamType>();
-  auto name = typeParam->getName().str();
+  auto interfaceType = type->getInterfaceType();
+  llvm::SmallString<16> name;
+  llvm::SmallString<16> displayName;
+  if (auto DMT =
+          llvm::dyn_cast<DependentMemberType>(interfaceType.getPointer())) {
+    std::function<void(DependentMemberType *)> visitDependentMembers =
+        [&](DependentMemberType *member) {
+          if (member == nullptr)
+            return;
+          if (auto *parent =
+                  llvm::dyn_cast<DependentMemberType>(member->getBase())) {
+            visitDependentMembers(parent);
+            name.append("$");
+            displayName.append(".");
+          }
+          name.append(member->getName().str());
+          displayName.append(member->getName().str());
+        };
+    name.append(DMT->getRootGenericParam()->getCanonicalName().str());
+    name.append("$");
+    displayName.append(DMT->getRootGenericParam()->getName().str());
+    displayName.append(".");
+    visitDependentMembers(DMT);
+  } else if (auto GTPT = llvm::dyn_cast<GenericTypeParamType>(
+                 interfaceType.getPointer())) {
+    name = GTPT->getCanonicalName().str();
+    displayName = GTPT->getName().str();
+  } else {
+    return;
+  }
 
   llvm::Value *data = value.getMetadata();
 
@@ -438,7 +471,7 @@ static void maybeEmitDebugInfoForLocalTypeData(IRGenFunction &IGF,
   // though; see the comment in IRGenFunctionSIL::emitShadowCopyIfNeeded().
   if (!IGF.IGM.IRGen.Opts.shouldOptimize() && !IGF.isAsync()) {
     auto alloca =
-        IGF.createAlloca(data->getType(), IGF.IGM.getPointerAlignment(), name);
+        IGF.createAlloca(data->getType(), IGF.IGM.getPointerAlignment(), displayName);
     IGF.Builder.CreateStore(data, alloca);
     data = alloca.getAddress();
   }
@@ -447,10 +480,12 @@ static void maybeEmitDebugInfoForLocalTypeData(IRGenFunction &IGF,
   if (!IGF.IGM.DebugInfo)
     return;
 
-  IGF.IGM.DebugInfo->emitTypeMetadata(IGF, data,
-                                      typeParam->getDepth(),
-                                      typeParam->getIndex(),
-                                      name);
+  if (proto) {
+    IGF.IGM.DebugInfo->emitWitnessTable(IGF, data, name, proto);
+  } else {
+    auto *typeParam = type->getInterfaceType()->castTo<GenericTypeParamType>();
+    IGF.IGM.DebugInfo->emitTypeMetadata(IGF, data, typeParam);
+  }
 }
 
 void

test/DebugInfo/move_function_dbginfo.swift

@@ -237,19 +237,19 @@ public func copyableVarArgTest(_ k: inout Klass) {
 // DWARF-NEXT: DW_AT_artificial        (true)
 //
 // DWARF: DW_TAG_variable
+// DWARF: DW_AT_location    
+// DWARF: DW_AT_name    ("$WT\317\204_0_0$$$s3out1P_pD")
+// DWARF: DW_AT_type    (
+// DWARF: DW_AT_artificial  (true)
+//
+// DWARF: DW_TAG_variable
 // DWARF-NEXT: DW_AT_location  (0x{{[a-z0-9]+}}:
 // DWARF-NEXT:    [0x{{[a-z0-9]+}}, 0x{{[a-z0-9]+}}):
 // DWARF-NEXT: DW_AT_name      ("k")
 // DWARF-NEXT: DW_AT_decl_file (
 // DWARF-NEXT: DW_AT_decl_line (
 // DWARF-NEXT: DW_AT_type      (
 //
-// DWARF: DW_TAG_variable
-// DWARF-NEXT: DW_AT_location  (
-// DWARF-NEXT: DW_AT_name      ("m")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
 public func addressOnlyValueTest<T : P>(_ x: T) {
     let k = x
     k.doSomething()
@@ -265,33 +265,6 @@ public func addressOnlyValueTest<T : P>(_ x: T) {
 // CHECK: ret void
 // CHECK-NEXT: }
 //
-// DWARF: DW_AT_linkage_name   ("$s3out23addressOnlyValueArgTestyyxnAA1PRzlF")
-// DWARF-NEXT: DW_AT_name      ("addressOnlyValueArgTest")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
-// DWARF-NEXT: DW_AT_external  (
-//
-// DWARF: DW_TAG_formal_parameter
-// DWARF-NEXT: DW_AT_location  (0x{{[a-z0-9]+}}:
-// DWARF-NEXT:    [0x{{[a-z0-9]+}}, 0x{{[a-z0-9]+}}):
-// DWARF-NEXT: DW_AT_name      ("k")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
-//
-// DWARF: DW_TAG_variable
-// DWARF-NEXT: DW_AT_location  (
-// DWARF-NEXT: DW_AT_name      ("$\317\204_0_0")
-// DWARF-NEXT: DW_AT_type      (
-// DWARF-NEXT: DW_AT_artificial        (true)
-//
-// DWARF: DW_TAG_variable
-// DWARF-NEXT: DW_AT_location  (
-// DWARF-NEXT: DW_AT_name      ("m")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
 public func addressOnlyValueArgTest<T : P>(_ k: __owned T) {
     k.doSomething()
     let m = consume k
@@ -306,35 +279,6 @@ public func addressOnlyValueArgTest<T : P>(_ k: __owned T) {
 // CHECK: ret void
 // CHECK-NEXT: }
 //
-// DWARF: DW_AT_linkage_name   ("$s3out18addressOnlyVarTestyyxAA1PRzlF")
-// DWARF-NEXT: DW_AT_name      ("addressOnlyVarTest")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
-// DWARF-NEXT: DW_AT_external  (
-//
-// DWARF: DW_TAG_formal_parameter
-// DWARF-NEXT: DW_AT_location  (
-// DWARF-NEXT: DW_AT_name      ("x")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
-//
-// DWARF: DW_TAG_variable
-// DWARF-NEXT: DW_AT_location  (
-// DWARF-NEXT: DW_AT_name      ("$\317\204_0_0")
-// DWARF-NEXT: DW_AT_type      (
-// DWARF-NEXT: DW_AT_artificial        (true)
-//
-// DWARF: DW_TAG_variable
-// DWARF-NEXT: DW_AT_location  (0x{{[a-z0-9]+}}:
-// DWARF-NEXT:    [0x{{[a-z0-9]+}}, 0x{{[a-z0-9]+}}):
-// TODO: Missing def in dbg info here.
-// DWARF-NEXT:    [0x{{[a-z0-9]+}}, 0x{{[a-z0-9]+}}):
-// DWARF-NEXT: DW_AT_name      ("k")
-// DWARF-NEXT: DW_AT_decl_file (
-// DWARF-NEXT: DW_AT_decl_line (
-// DWARF-NEXT: DW_AT_type      (
 public func addressOnlyVarTest<T : P>(_ x: T) {
     var k = x // << this
     k.doSomething()