Debug Info: Ensure classes report their storage size correctly

by wrapping them in a pointer-sized struct as we do for all things passed
by reference.

Fixes rdar://21409965

Swift SVN r29455

Author: adrian-prantl

lib/IRGen/IRGenDebugInfo.cpp

@@ -1534,17 +1534,14 @@ llvm::DIType *IRGenDebugInfo::createType(DebugTypeInfo DbgTy,
     auto *ClassTy = BaseTy->castTo<ClassType>();
     auto *Decl = ClassTy->getDecl();
     Location L = getLoc(SM, Decl);
-    // TODO: We may want to peek at Decl->isObjC() and set this
-    // attribute accordingly.
-    auto RuntimeLang = llvm::dwarf::DW_LANG_Swift;
     if (auto *ClangDecl = Decl->getClangDecl()) {
       auto ClangSrcLoc = ClangDecl->getLocStart();
       clang::SourceManager &ClangSM =
           CI.getClangASTContext().getSourceManager();
       L.Line = ClangSM.getPresumedLineNumber(ClangSrcLoc);
       L.Filename = ClangSM.getBufferName(ClangSrcLoc);
 
-     // Use "ObjectiveC" as default for implicit decls.
+      // Use "ObjectiveC" as default for implicit decls.
       // FIXME 1: Do something more clever based on the decl's mangled name.
       // FIXME 2: Clang submodules are not handled here.
       StringRef ModuleName = "ObjectiveC";
@@ -1555,11 +1552,9 @@ llvm::DIType *IRGenDebugInfo::createType(DebugTypeInfo DbgTy,
       // This placeholder gets RAUW'd by finalize().
       Scope = getOrCreateModule(ModuleFile, ModuleName, ModuleFile);
     }
-    return createStructType(DbgTy, Decl, ClassTy, Scope,
-                            getOrCreateFile(L.Filename), L.Line, SizeInBits,
-                            AlignInBits, Flags,
-                            nullptr, // DerivedFrom
-                            RuntimeLang, MangledName);
+    return createPointerSizedStruct(Scope, Decl->getNameStr(),
+                                    getOrCreateFile(L.Filename), L.Line, Flags,
+                                    MangledName);
   }
 
   case TypeKind::Protocol: {

test/DebugInfo/structs.swift

@@ -1,6 +1,6 @@
 // RUN: %target-swift-frontend -primary-file %s -emit-ir -g -o - | FileCheck %s
-
-// This is more of a crash test than anything else.
+// Capture the pointer size from type Int
+// CHECK: %Si = type <{ i[[PTRSIZE:[0-9]+]] }>
 
 struct A {
   var fn : () -> ()
@@ -9,8 +9,22 @@ struct A {
 func test(var x : A) {}
 // CHECK:    define hidden void @_TF7structs4test
 // CHECK:      [[X:%.*]] = alloca [[A:%.*]], align {{(4|8)}}
-// CHECK-NEXT: call void @llvm.dbg.declare(metadata [[A]]* [[X]], metadata [[X_DBG:!.*]], metadata !{{[0-9]+}})
+// CHECK-NEXT: call void @llvm.dbg.declare(metadata [[A]]* [[X]],
+// CHECK-SAME:                             metadata [[X_DBG:!.*]], metadata
 // CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "A"
 // CHECK-SAME:             identifier: [[A_DI:"[^"]+"]]
+
+class C {
+  var lots_of_extra_storage: (Int, Int, Int) = (1, 2, 3)
+  var member: C = C()
+}
+
+// A class is represented by a pointer, so B's total size should be PTRSIZE.
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "B",
+// CHECK-SAME:             {{.*}}size: [[PTRSIZE]]
+struct B {
+  var c : C
+}
+
 // CHECK: [[X_DBG]] = !DILocalVariable(tag: DW_TAG_arg_variable, name: "x",
-// CHECK-SAME:             type: ![[A_DI]]
+// CHECK-SAME:                         type: ![[A_DI]]

test/DebugInfo/test-foundation.swift

@@ -36,22 +36,14 @@ class MyObject : NSObject {
   // LOC-CHECK: ret {{.*}}, !dbg ![[DBG:.*]]
   // LOC-CHECK: ret
   var MyArr = NSArray()
-// Capture the pointer size from type Int
-// IMPORT-CHECK: %Si = type <{ i[[PTRSIZE:[0-9]+]] }>
 // IMPORT-CHECK: filename: "test-foundation.swift"
 // IMPORT-CHECK: !MDModule(name: "ObjectiveC"
-// IMPORT-CHECK: !DIDerivedType(tag: DW_TAG_member, name: "MyArr",
-// IMPORT-CHECK-NOT:            line:
-// IMPORT-CHECK-SAME:           baseType: ![[NSARRAY:"[^"]+"]]
-// IMPORT-CHECK-SAME:           size: [[PTRSIZE]], align: [[PTRSIZE]]
-// IMPORT-CHECK-NOT:            offset: 0
-// IMPORT-CHECK-SAME:           ){{$}}
-// IMPORT-CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "NSArray", scope: ![[FOUNDATION:[0-9]+]]
-// IMPORT-CHECK-SAME:             identifier: [[NSARRAY]]
-// IMPORT-CHECK: [[FOUNDATION]] = !MDModule(name: "Foundation",{{.*}} file: ![[FOUNDATION_FILE:[0-9]+]]
+// IMPORT-CHECK: [[FOUNDATION:[0-9]+]] = !MDModule(name: "Foundation",
+// IMPORT-CHECK-SAME:                        {{.*}}file: ![[FOUNDATION_FILE:[0-9]+]]
 // IMPORT-CHECK: ![[FOUNDATION_FILE]] = !DIFile(filename: "Foundation-{{.*}}.pcm"
-// IMPORT-CHECK: !DIImportedEntity(tag: DW_TAG_imported_module,{{.*}} entity: ![[FOUNDATION]]
-
+// IMPORT-CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "NSArray",
+// IMPORT-CHECK-SAME:             scope: ![[FOUNDATION]]
+// IMPORT-CHECK: !DIImportedEntity(tag: DW_TAG_imported_module, {{.*}}entity: ![[FOUNDATION]]
 
   // Force the use of Int.
   var count : Int = 0