Emit debug info for generic type aliases. …

lib/IRGen/DebugTypeInfo.cpp

@@ -60,20 +60,25 @@ DebugTypeInfo DebugTypeInfo::getFromTypeInfo(swift::Type Ty,
 
 DebugTypeInfo DebugTypeInfo::getLocalVariable(VarDecl *Decl, swift::Type Ty,
                                               const TypeInfo &Info) {
-
-  auto DeclType = Decl->getInterfaceType();
-  auto RealType = Ty;
-
-  // DynamicSelfType is also sugar as far as debug info is concerned.
-  auto Sugared = DeclType;
-  if (auto DynSelfTy = DeclType->getAs<DynamicSelfType>())
-    Sugared = DynSelfTy->getSelfType();
-
   // Prefer the original, potentially sugared version of the type if
   // the type hasn't been mucked with by an optimization pass.
-  auto *Type = Sugared->isEqual(RealType) ? DeclType.getPointer()
-                                          : RealType.getPointer();
-  return getFromTypeInfo(Type, Info);
+  swift::Type DeclType = Decl->getInterfaceType();
+  swift::Type RealType = Ty;
+
+  swift::Type DebugType;
+  if (auto DynSelfTy = DeclType->getAs<DynamicSelfType>()) {
+    // DynamicSelfType is also sugar as far as debug info is concerned.
+    auto DesugaredSelf = DynSelfTy->getSelfType();
+    DebugType = DesugaredSelf->isEqual(RealType) ? DynSelfTy : RealType;
+  } else {
+    // Map the sugared type into the context to resolve bound generics and
+    // generic type aliases.
+    DeclContext *DeclCtx = Decl->getDeclContext();
+    swift::Type Sugared =
+        DeclCtx ? DeclCtx->mapTypeIntoContext(DeclType) : DeclType;
+    DebugType = Sugared->isEqual(RealType) ? Sugared : RealType;
+  }
+  return getFromTypeInfo(DebugType, Info);
 }
 
 DebugTypeInfo DebugTypeInfo::getMetadata(swift::Type Ty, llvm::Type *StorageTy,

lib/IRGen/IRGenSIL.cpp

@@ -3660,7 +3660,7 @@ void IRGenSILFunction::visitDebugValueInst(DebugValueInst *i) {
   llvm::SmallVector<llvm::Value *, 8> Copy;
   emitShadowCopyIfNeeded(SILVal, i->getDebugScope(), *VarInfo, IsAnonymous,
                          Copy);
-  bindArchetypes(DbgTy.getType());
+  bindArchetypes(RealTy);
   if (!IGM.DebugInfo)
     return;
 
@@ -3691,7 +3691,7 @@ void IRGenSILFunction::visitDebugValueAddrInst(DebugValueAddrInst *i) {
 
   auto DbgTy = DebugTypeInfo::getLocalVariable(
       Decl, RealType, getTypeInfo(SILVal->getType()));
-  bindArchetypes(DbgTy.getType());
+  bindArchetypes(RealType);
   if (!IGM.DebugInfo)
     return;
 
@@ -3991,7 +3991,7 @@ void IRGenSILFunction::emitDebugInfoForAllocStack(AllocStackInst *i,
   auto RealType = SILTy.getASTType();
   auto DbgTy = DebugTypeInfo::getLocalVariable(Decl, RealType, type);
 
-  bindArchetypes(DbgTy.getType());
+  bindArchetypes(RealType);
   if (IGM.DebugInfo)
     emitDebugVariableDeclaration(addr, DbgTy, SILTy, DS, Decl, *VarInfo,
                                  Indirection);

test/DebugInfo/bound-generic-struct-extension.swift

@@ -0,0 +1,28 @@
+// RUN: %target-swift-frontend %s -emit-ir -g -o - | %FileCheck %s
+
+// Test that a bound generic type is fully resolved in the debug info.
+
+public protocol P {}
+
+public struct S : P {
+  var x: Int
+}
+// This is significant, it must be bound to S:                    main.BoundGeneric<main.S>
+// CHECK-DAG: ![[S:[0-9]+]] = !DICompositeType({{.*}}identifier: "$s4main12BoundGenericVyAA1SVGD")
+
+public extension BoundGeneric where T == S {
+  func f() {
+// CHECK-DAG: !DILocalVariable(name: "self", arg: 1,{{.*}} line: [[@LINE-1]],{{.*}} type: ![[C_BGS:[0-9]+]],
+// CHECK-DAG: ![[C_BGS]] = !DIDerivedType(tag: DW_TAG_const_type,{{.*}} baseType: ![[BGS:[0-9]+]])
+// CHECK-DAG: ![[BGS]] = !DICompositeType(tag: DW_TAG_structure_type,{{.*}} elements: ![[ELTS:[0-9]+]],
+// CHECK-DAG: ![[ELTS]] = !{![[MEMBER:[0-9]+]]}
+// CHECK-DAG: ![[MEMBER]] = !DIDerivedType(tag: DW_TAG_member,{{.*}} baseType: ![[S]],
+  }
+}
+
+public struct BoundGeneric<T> where T : P {
+  let x : T
+}
+
+public let pat = BoundGeneric<S>(x: S(x: 23))
+pat.f()

test/DebugInfo/generic-typealias.swift

@@ -0,0 +1,19 @@
+// RUN: %target-swift-frontend %s -emit-ir -g -o - | %FileCheck %s
+
+// Test that a generic type alias is represented in the debug info.
+
+public struct S<T> {
+  public typealias Alias = (T, T)
+  // CHECK: ![[T_T:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "$sx_xtD"
+  public let member : Alias
+  public func f(t : Alias) -> Alias { return t }
+  // CHECK: !DILocalVariable(name: "t", arg: 1,{{.*}} line: [[@LINE-1]],
+  // CHECK-SAME:             type: ![[C_ALIAS:[0-9]+]])
+  // CHECK: ![[C_ALIAS]] = !DIDerivedType(tag: DW_TAG_const_type,
+  // CHECK-SAME:                          baseType: ![[ALIAS:[0-9]+]])
+  // CHECK: ![[ALIAS]] = !DIDerivedType(tag: DW_TAG_typedef, name: "$
+  // CHECK-SAME:                        baseType: ![[T_T]])
+
+}
+
+public let s = S<Int>(member: (4, 2))