[Debug info] Retain all type aliases in asttypes mode

Bound generic types don't reference their type parameters in ASTTypes
mode, so we need to artificially keep typealiases alive, since they can
appear in reflection metadata.

rdar://143595521

Author: adrian-prantl

lib/IRGen/IRGenDebugInfo.cpp

@@ -2182,8 +2182,14 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
           DbgTy.getAlignment(), DbgTy.hasDefaultAlignment(),
           /* IsMetadataType = */ false, DbgTy.isFixedBuffer(),
           DbgTy.getNumExtraInhabitants());
-      return DBuilder.createTypedef(getOrCreateType(AliasedDbgTy), MangledName,
-                                    L.File, 0, Scope);
+      auto *TypeDef = DBuilder.createTypedef(getOrCreateType(AliasedDbgTy),
+                                             MangledName, L.File, 0, Scope);
+      // Bound generic types don't reference their type parameters in ASTTypes
+      // mode, so we need to artificially keep typealiases alive, since they can
+      // appear in reflection metadata.
+      if (Opts.DebugInfoLevel < IRGenDebugInfoLevel::DwarfTypes)
+        DBuilder.retainType(TypeDef);
+      return TypeDef;
     }
 
     case TypeKind::Locatable: {

test/DebugInfo/PrivateDiscriminator.swift

@@ -7,7 +7,7 @@
 // RUN: %target-swift-frontend %S/../Inputs/empty.swift -primary-file %s \
 // RUN:   -emit-ir -g | %FileCheck %s
 // CHECK: !DICompileUnit({{.*}}flags: {{[^,]*}}-private-discriminator [[DISCRIMINATOR:_[A-Z0-9]+]]
-// CHECK: ![[MOD:.*]] = !DIModule(scope: null,
+// CHECK: ![[MOD:.*]] = !DIModule(scope: null, name: "empty"
 // CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "InA",
 // CHECK-SAME:             scope: ![[A:[0-9]+]],
 // CHECK: ![[A]] = !DICompositeType(tag: DW_TAG_structure_type, name: "A",

test/DebugInfo/local_type_originally_defined_in.swift

@@ -7,7 +7,7 @@ import local_type_originally_defined_in_other
 
 public func definedInOtherModule() {
   let s = Sheep()
-  // CHECK: DICompositeType(tag: DW_TAG_structure_type, name: "Sheep"{{.*}}identifier: "$s4Barn5SheepCD
+  // CHECK-DAG: DICompositeType(tag: DW_TAG_structure_type, name: "Sheep"{{.*}}identifier: "$s4Barn5SheepCD
 }
 public func localTypeAliasTest(horse: Horse) {
   // The local type mangling for 'A' mentions 'Horse', which must
@@ -18,7 +18,7 @@ public func localTypeAliasTest(horse: Horse) {
 
   let info = UnsafeMutablePointer<A>.allocate(capacity: 1)
   _ = info
-  // CHECK: DIDerivedType(tag: DW_TAG_typedef, name: "$s32local_type_originally_defined_in0A13TypeAliasTest5horsey4Barn5HorseV_tF1AL_aD"
+  // CHECK-DAG: DIDerivedType(tag: DW_TAG_typedef, name: "$s32local_type_originally_defined_in0A13TypeAliasTest5horsey4Barn5HorseV_tF1AL_aD"
 }
 
 
@@ -31,7 +31,7 @@ public func localTypeTest(horse: Horse) {
 
   let info = UnsafeMutablePointer<LocalStruct>.allocate(capacity: 1)
   _ = info
-  // CHECK: DICompositeType(tag: DW_TAG_structure_type, name: "$s32local_type_originally_defined_in0A8TypeTest5horsey4Barn5HorseV_tF11LocalStructL_VD"
+  // CHECK-DAG: DICompositeType(tag: DW_TAG_structure_type, name: "$s32local_type_originally_defined_in0A8TypeTest5horsey4Barn5HorseV_tF11LocalStructL_VD"
 }
 
 public func localTypeAliasTest() -> Horse {
@@ -40,7 +40,7 @@ public func localTypeAliasTest() -> Horse {
   let info = UnsafeMutablePointer<B>.allocate(capacity: 1)
   _ = info
   return Horse()
-  // CHECK: DIDerivedType(tag: DW_TAG_typedef, name: "$s32local_type_originally_defined_in0A13TypeAliasTest4Barn5HorseVyF1BL_aD"
+  // CHECK-DAG: DIDerivedType(tag: DW_TAG_typedef, name: "$s32local_type_originally_defined_in0A13TypeAliasTest4Barn5HorseVyF1BL_aD"
 }
 
 public func localTypeAliasTestGeneric<T: Cow>(cow: T) {

test/DebugInfo/protocol-extension.swift

@@ -15,6 +15,5 @@ public extension P {
   }
 }
 
-// CHECK: ![[SELFMETA]] = !DILocalVariable(name: "$\CF\84_0_0",
-// CHECK-SAME: type: ![[SELFTY:[0-9]+]], flags: DIFlagArtificial)
-// CHECK: ![[SELFTY]] = !DIDerivedType(tag: DW_TAG_typedef, name: "Self"
+// CHECK-DAG: ![[SELFMETA]] = !DILocalVariable(name: "$\CF\84_0_0", {{.*}}type: ![[SELFTY:[0-9]+]], flags: DIFlagArtificial)
+// CHECK-DAG: ![[SELFTY]] = !DIDerivedType(tag: DW_TAG_typedef, name: "Self"

test/DebugInfo/test-foundation.swift

@@ -18,7 +18,7 @@ class MyObject : NSObject {
   // LOC-CHECK: ret
   @objc var MyArr = NSArray()
   // IMPORT-CHECK: filename: "{{.*}}test-foundation.swift"
-  // IMPORT-CHECK-DAG: [[FOUNDATION:[0-9]+]] = !DIModule({{.*}} name: "Foundation",{{.*}} includePath: {{.*}}Foundation.framework
+  // IMPORT-CHECK-DAG: [[FOUNDATION:[0-9]+]] = !DIModule({{.*}} name: "Foundation",{{.*}} includePath: {{.*}}Foundation.framework"
   // IMPORT-CHECK-DAG: [[OVERLAY:[0-9]+]] = !DIModule({{.*}} name: "Foundation",{{.*}} includePath: {{.*}}Foundation.swiftmodule
   // IMPORT-CHECK-DAG: !DICompositeType(tag: DW_TAG_structure_type, name: "NSArray", scope: ![[NSARRAY:[0-9]+]]
   //  IMPORT-CHECK-DAG: ![[NSARRAY]] = !DIModule(scope: ![[FOUNDATION:[0-9]+]], name: "NSArray"

test/DebugInfo/typealias_indirect.swift

@@ -0,0 +1,8 @@
+// RUN: %target-swift-frontend %s -emit-ir -parse-as-library -module-name a -g -o - | %FileCheck %s
+// CHECK: !DIDerivedType(tag: DW_TAG_typedef, name: "$s1a10LocalAliasaD", {{.*}}baseType: ![[BASETY:[0-9]+]]
+// CHECK: ![[BASETY]]{{.*}}$sSbD
+public class MyClass<A, B> {}
+public typealias LocalAlias = Bool
+public typealias ClassAlias = MyClass<LocalAlias, Bool>
+public func use(cls: ClassAlias?) {}
+

test/DebugInfo/typearg.swift

@@ -9,12 +9,9 @@ class AClass : AProtocol {
 
 // CHECK: define hidden {{.*}}void @{{.*}}aFunction
 // CHECK:  #dbg_declare(ptr %{{.*}}, ![[TYPEARG:.*]], !DIExpression(),
-// CHECK: ![[TYPEARG]] = !DILocalVariable(name: "$\CF\84_0_0"
-// CHECK-SAME:                            type: ![[SWIFTMETATYPE:[^,)]+]]
-// CHECK-SAME:                            flags: DIFlagArtificial
-// CHECK: ![[SWIFTMETATYPE]] = !DIDerivedType(tag: DW_TAG_typedef, name: "T",
-// CHECK-SAME:                                baseType: ![[VOIDPTR:[0-9]+]]
-// CHECK: ![[VOIDPTR]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "$sBpD", baseType: null
+// CHECK-DAG: ![[TYPEARG]] = !DILocalVariable(name: "$\CF\84_0_0"{{.*}}type: ![[SWIFTMETATYPE:[^,)]+]]{{.*}}flags: DIFlagArtificial
+// CHECK-DAG: ![[SWIFTMETATYPE]] = !DIDerivedType(tag: DW_TAG_typedef, name: "T",{{.*}}baseType: ![[VOIDPTR:[0-9]+]]
+// CHECK-DAG: ![[VOIDPTR]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "$sBpD", baseType: null
 func aFunction<T : AProtocol>(_ x: T) {
     print("I am in aFunction: \(x.f())")
 }