[vm] Hide internal implementation List types and expose them as List

When taking a type of an instance with x.runtimeType we can map
internal classes _List, _ImmutableList and _GrowableList to a
user-visible List class. This is similar to what we do for
implementation classes of int, String and Type.
After that, result of x.runtimeType for built-in lists would be
compatible with List<T> type literals.

Also, both intrinsic and native implementations of _haveSameRuntimeType
are updated to agree with new semantic of runtimeType.

TEST=co19/LanguageFeatures/Constructor-tear-offs/type_literal_A01_t01
TEST=runtime/tests/vm/dart/have_same_runtime_type_test

Fixes #46893
Issue #46231

Change-Id: Ie24a9f527f66a06118427b7a09e49c03dff93d8e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/210066
Commit-Queue: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Tess Strickland <sstrickl@google.com>

runtime/lib/object.cc

@@ -101,14 +101,18 @@ static bool HaveSameRuntimeTypeHelper(Zone* zone,
   if (left_cid != right_cid) {
     if (IsIntegerClassId(left_cid)) {
       return IsIntegerClassId(right_cid);
-    }
-    if (IsStringClassId(left_cid)) {
+    } else if (IsStringClassId(left_cid)) {
       return IsStringClassId(right_cid);
-    }
-    if (IsTypeClassId(left_cid)) {
+    } else if (IsTypeClassId(left_cid)) {
       return IsTypeClassId(right_cid);
+    } else if (IsArrayClassId(left_cid)) {
+      if (!IsArrayClassId(right_cid)) {
+        return false;
+      }
+      // Still need to check type arguments.
+    } else {
+      return false;
     }
-    return false;
   }
 
   if (left_cid == kClosureCid) {

runtime/tests/vm/dart/have_same_runtime_type_test.dart

@@ -0,0 +1,32 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Test for corner cases of 'a.runtimeType == b.runtimeType' pattern
+// which is recognized and optimized in AOT mode.
+
+import "package:expect/expect.dart";
+
+@pragma('vm:never-inline')
+Object getType(Object obj) => obj.runtimeType;
+
+@pragma('vm:never-inline')
+void test(bool expected, Object a, Object b) {
+  bool result1 = getType(a) == getType(b);
+  bool result2 = a.runtimeType == b.runtimeType;
+  Expect.equals(expected, result1);
+  Expect.equals(expected, result2);
+}
+
+typedef Func = void Function();
+
+void main() {
+  test(true, 0x7fffffffffffffff, int.parse('42'));
+  test(true, 'hi', String.fromCharCode(1114111));
+  test(false, 'hi', 1);
+  test(true, List, Func);
+  test(true, <int>[1], const <int>[2]);
+  test(true, const <String>[], List<String>.filled(1, ''));
+  test(true, <String>[]..add('hi'), List<String>.filled(2, ''));
+  test(false, <int>[], <String>[]);
+}

runtime/tests/vm/dart_2/have_same_runtime_type_test.dart

@@ -0,0 +1,34 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Test for corner cases of 'a.runtimeType == b.runtimeType' pattern
+// which is recognized and optimized in AOT mode.
+
+// @dart = 2.9
+
+import "package:expect/expect.dart";
+
+@pragma('vm:never-inline')
+Object getType(Object obj) => obj.runtimeType;
+
+@pragma('vm:never-inline')
+void test(bool expected, Object a, Object b) {
+  bool result1 = getType(a) == getType(b);
+  bool result2 = a.runtimeType == b.runtimeType;
+  Expect.equals(expected, result1);
+  Expect.equals(expected, result2);
+}
+
+typedef Func = void Function();
+
+void main() {
+  test(true, 0x7fffffffffffffff, int.parse('42'));
+  test(true, 'hi', String.fromCharCode(1114111));
+  test(false, 'hi', 1);
+  test(true, List, Func);
+  test(true, <int>[1], const <int>[2]);
+  test(true, const <String>[], List<String>.filled(1, ''));
+  test(true, <String>[]..add('hi'), List<String>.filled(2, ''));
+  test(false, <int>[], <String>[]);
+}

runtime/vm/class_id.h

@@ -78,7 +78,6 @@ typedef uint16_t ClassIdTagType;
   V(Mint)                                                                      \
   V(Double)                                                                    \
   V(Bool)                                                                      \
-  V(GrowableObjectArray)                                                       \
   V(Float32x4)                                                                 \
   V(Int32x4)                                                                   \
   V(Float64x2)                                                                 \
@@ -108,10 +107,14 @@ typedef uint16_t ClassIdTagType;
 // TODO(http://dartbug.com/45908): Add ImmutableLinkedHashSet.
 #define CLASS_LIST_SETS(V) V(LinkedHashSet)
 
-#define CLASS_LIST_ARRAYS(V)                                                   \
+#define CLASS_LIST_FIXED_LENGTH_ARRAYS(V)                                      \
   V(Array)                                                                     \
   V(ImmutableArray)
 
+#define CLASS_LIST_ARRAYS(V)                                                   \
+  CLASS_LIST_FIXED_LENGTH_ARRAYS(V)                                            \
+  V(GrowableObjectArray)
+
 #define CLASS_LIST_STRINGS(V)                                                  \
   V(String)                                                                    \
   V(OneByteString)                                                             \
@@ -182,6 +185,7 @@ typedef uint16_t ClassIdTagType;
   V(LinkedHashMap)                                                             \
   V(LinkedHashSet)                                                             \
   V(Array)                                                                     \
+  V(GrowableObjectArray)                                                       \
   V(String)
 
 #define CLASS_LIST_NO_OBJECT(V)                                                \
@@ -329,11 +333,15 @@ inline bool IsExternalStringClassId(intptr_t index) {
           index == kExternalTwoByteStringCid);
 }
 
+inline bool IsArrayClassId(intptr_t index) {
+  COMPILE_ASSERT(kImmutableArrayCid == kArrayCid + 1);
+  COMPILE_ASSERT(kGrowableObjectArrayCid == kArrayCid + 2);
+  return (index >= kArrayCid && index <= kGrowableObjectArrayCid);
+}
+
 inline bool IsBuiltinListClassId(intptr_t index) {
   // Make sure this function is updated when new builtin List types are added.
-  COMPILE_ASSERT(kImmutableArrayCid == kArrayCid + 1);
-  return ((index >= kArrayCid && index <= kImmutableArrayCid) ||
-          (index == kGrowableObjectArrayCid) || IsTypedDataBaseClassId(index) ||
+  return (IsArrayClassId(index) || IsTypedDataBaseClassId(index) ||
           (index == kByteBufferCid));
 }
 

runtime/vm/compiler/asm_intrinsifier_arm.cc

@@ -1198,6 +1198,14 @@ static void JumpIfNotString(Assembler* assembler,
              kIfNotInRange, target);
 }
 
+static void JumpIfNotList(Assembler* assembler,
+                          Register cid,
+                          Register tmp,
+                          Label* target) {
+  RangeCheck(assembler, cid, tmp, kArrayCid, kGrowableObjectArrayCid,
+             kIfNotInRange, target);
+}
+
 static void JumpIfType(Assembler* assembler,
                        Register cid,
                        Register tmp,
@@ -1284,7 +1292,7 @@ static void EquivalentClassIds(Assembler* assembler,
                                Register scratch,
                                bool testing_instance_cids) {
   Label different_cids, equal_cids_but_generic, not_integer,
-      not_integer_or_string;
+      not_integer_or_string, not_integer_or_string_or_list;
 
   // Check if left hand side is a closure. Closures are handled in the runtime.
   __ CompareImmediate(cid1, kClosureCid);
@@ -1310,7 +1318,8 @@ static void EquivalentClassIds(Assembler* assembler,
   __ b(equal);
 
   // Class ids are different. Check if we are comparing two string types (with
-  // different representations) or two integer types or two type types.
+  // different representations), two integer types, two list types or two type
+  // types.
   __ Bind(&different_cids);
   __ CompareImmediate(cid1, kNumPredefinedCids);
   __ b(not_equal, HI);
@@ -1335,9 +1344,20 @@ static void EquivalentClassIds(Assembler* assembler,
 
   if (testing_instance_cids) {
     __ Bind(&not_integer_or_string);
+    // Check if both are List types.
+    JumpIfNotList(assembler, cid1, scratch, &not_integer_or_string_or_list);
+
+    // First type is a List. Check if the second is a List too.
+    JumpIfNotList(assembler, cid2, scratch, not_equal);
+    ASSERT(compiler::target::Array::type_arguments_offset() ==
+           compiler::target::GrowableObjectArray::type_arguments_offset());
+    __ LoadImmediate(scratch, compiler::target::Array::type_arguments_offset());
+    __ b(&equal_cids_but_generic);
+
+    __ Bind(&not_integer_or_string_or_list);
     // Check if the first type is a Type. If it is not then types are not
     // equivalent because they have different class ids and they are not String
-    // or integer or Type.
+    // or integer or List or Type.
     JumpIfNotType(assembler, cid1, scratch, not_equal);
 
     // First type is a Type. Check if the second is a Type too.

runtime/vm/compiler/asm_intrinsifier_arm64.cc

@@ -1342,6 +1342,14 @@ static void JumpIfNotString(Assembler* assembler,
              kIfNotInRange, target);
 }
 
+static void JumpIfNotList(Assembler* assembler,
+                          Register cid,
+                          Register tmp,
+                          Label* target) {
+  RangeCheck(assembler, cid, tmp, kArrayCid, kGrowableObjectArrayCid,
+             kIfNotInRange, target);
+}
+
 static void JumpIfType(Assembler* assembler,
                        Register cid,
                        Register tmp,
@@ -1432,7 +1440,7 @@ static void EquivalentClassIds(Assembler* assembler,
                                Register scratch,
                                bool testing_instance_cids) {
   Label different_cids, equal_cids_but_generic, not_integer,
-      not_integer_or_string;
+      not_integer_or_string, not_integer_or_string_or_list;
 
   // Check if left hand side is a closure. Closures are handled in the runtime.
   __ CompareImmediate(cid1, kClosureCid);
@@ -1458,7 +1466,8 @@ static void EquivalentClassIds(Assembler* assembler,
   __ b(equal);
 
   // Class ids are different. Check if we are comparing two string types (with
-  // different representations) or two integer types or two type types.
+  // different representations), two integer types, two list types or two type
+  // types.
   __ Bind(&different_cids);
   __ CompareImmediate(cid1, kNumPredefinedCids);
   __ b(not_equal, HI);
@@ -1483,9 +1492,20 @@ static void EquivalentClassIds(Assembler* assembler,
 
   if (testing_instance_cids) {
     __ Bind(&not_integer_or_string);
+    // Check if both are List types.
+    JumpIfNotList(assembler, cid1, scratch, &not_integer_or_string_or_list);
+
+    // First type is a List. Check if the second is a List too.
+    JumpIfNotList(assembler, cid2, scratch, not_equal);
+    ASSERT(compiler::target::Array::type_arguments_offset() ==
+           compiler::target::GrowableObjectArray::type_arguments_offset());
+    __ LoadImmediate(scratch, compiler::target::Array::type_arguments_offset());
+    __ b(&equal_cids_but_generic);
+
+    __ Bind(&not_integer_or_string_or_list);
     // Check if the first type is a Type. If it is not then types are not
     // equivalent because they have different class ids and they are not String
-    // or integer or Type.
+    // or integer or List or Type.
     JumpIfNotType(assembler, cid1, scratch, not_equal);
 
     // First type is a Type. Check if the second is a Type too.

runtime/vm/compiler/asm_intrinsifier_ia32.cc

@@ -1281,6 +1281,11 @@ static void JumpIfNotString(Assembler* assembler, Register cid, Label* target) {
              kIfNotInRange, target);
 }
 
+static void JumpIfNotList(Assembler* assembler, Register cid, Label* target) {
+  RangeCheck(assembler, cid, kArrayCid, kGrowableObjectArrayCid, kIfNotInRange,
+             target);
+}
+
 static void JumpIfType(Assembler* assembler, Register cid, Label* target) {
   RangeCheck(assembler, cid, kTypeCid, kFunctionTypeCid, kIfInRange, target);
 }
@@ -1370,7 +1375,7 @@ static void EquivalentClassIds(Assembler* assembler,
                                Register scratch,
                                bool testing_instance_cids) {
   Label different_cids, equal_cids_but_generic, not_integer,
-      not_integer_or_string;
+      not_integer_or_string, not_integer_or_string_or_list;
 
   // Check if left hand side is a closure. Closures are handled in the runtime.
   __ cmpl(cid1, Immediate(kClosureCid));
@@ -1392,11 +1397,12 @@ static void EquivalentClassIds(Assembler* assembler,
           scratch,
           target::Class::host_type_arguments_field_offset_in_words_offset()));
   __ cmpl(scratch, Immediate(target::Class::kNoTypeArguments));
-  __ j(NOT_EQUAL, &equal_cids_but_generic, Assembler::kNearJump);
+  __ j(NOT_EQUAL, &equal_cids_but_generic);
   __ jmp(equal);
 
   // Class ids are different. Check if we are comparing two string types (with
-  // different representations) or two integer types or two type types.
+  // different representations), two integer types, two list types or two type
+  // types.
   __ Bind(&different_cids);
   __ cmpl(cid1, Immediate(kNumPredefinedCids));
   __ j(ABOVE_EQUAL, not_equal);
@@ -1406,25 +1412,42 @@ static void EquivalentClassIds(Assembler* assembler,
   JumpIfNotInteger(assembler, scratch, &not_integer);
 
   // First type is an integer. Check if the second is an integer too.
-  JumpIfInteger(assembler, cid2, equal);
+  __ movl(scratch, cid2);
+  JumpIfInteger(assembler, scratch, equal);
   // Integer types are only equivalent to other integer types.
   __ jmp(not_equal);
 
   __ Bind(&not_integer);
   // Check if both are String types.
-  JumpIfNotString(assembler, cid1,
+  __ movl(scratch, cid1);
+  JumpIfNotString(assembler, scratch,
                   testing_instance_cids ? &not_integer_or_string : not_equal);
 
   // First type is a String. Check if the second is a String too.
-  JumpIfString(assembler, cid2, equal);
+  __ movl(scratch, cid2);
+  JumpIfString(assembler, scratch, equal);
   // String types are only equivalent to other String types.
   __ jmp(not_equal);
 
   if (testing_instance_cids) {
     __ Bind(&not_integer_or_string);
+    // Check if both are List types.
+    __ movl(scratch, cid1);
+    JumpIfNotList(assembler, scratch, &not_integer_or_string_or_list);
+
+    // First type is a List. Check if the second is a List too.
+    __ movl(scratch, cid2);
+    JumpIfNotList(assembler, scratch, not_equal);
+    ASSERT(compiler::target::Array::type_arguments_offset() ==
+           compiler::target::GrowableObjectArray::type_arguments_offset());
+    __ movl(scratch,
+            Immediate(compiler::target::Array::type_arguments_offset()));
+    __ jmp(&equal_cids_but_generic, Assembler::kNearJump);
+
+    __ Bind(&not_integer_or_string_or_list);
     // Check if the first type is a Type. If it is not then types are not
     // equivalent because they have different class ids and they are not String
-    // or integer or Type.
+    // or integer or List or Type.
     JumpIfNotType(assembler, cid1, not_equal);
 
     // First type is a Type. Check if the second is a Type too.