[torque]: Fix sharing of re-opened namespaces

In the process, create a shared array utility GetLengthProperty that fast-paths
accessing the length properties of JSArray.

Bug: v8:7793
Change-Id: I6d7f0007c162794773dc0fc3e8bf12b3adf12fa0
Reviewed-on: https://chromium-review.googlesource.com/1116221
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54133}

src/builtins/array-foreach.tq

@@ -137,8 +137,7 @@ module array {
       let o: Object = ToObject(context, receiver);
 
       // 2. Let len be ? ToLength(? Get(O, "length")).
-      let len: Number =
-          ToLength_Inline(context, GetProperty(context, o, 'length'));
+      let len: Number = GetLengthProperty(context, o);
 
       // 3. If IsCallable(callbackfn) is false, throw a TypeError exception.
       if (arguments.length == 0) {

src/builtins/array-sort.tq

@@ -568,8 +568,7 @@ module array {
     }
     label slow {
       // 3. Let len be ? ToLength(? Get(obj, "length")).
-      let len: Number =
-          ToLength_Inline(context, GetProperty(context, obj, 'length'));
+      let len: Number = GetLengthProperty(context, obj);
 
       if (len < 2) return receiver;
       let nofNonUndefined: Smi = PrepareElementsForSort(context, obj, len);

src/builtins/array.tq

@@ -3,6 +3,16 @@
 // found in the LICENSE file.
 
 module array {
+  macro GetLengthProperty(context: Context, o: Object): Number {
+    if (BranchIfFastJSArray(o, context)) {
+      let a: JSArray = unsafe_cast<JSArray>(o);
+      return a.length_fast;
+    } else
+      deferred {
+        return ToLength_Inline(context, GetProperty(context, o, 'length'));
+      }
+  }
+
   macro FastArraySplice(
       context: Context, args: constexpr Arguments, o: Object,
       originalLengthNumber: Number, actualStartNumber: Number, insertCount: Smi,
@@ -103,8 +113,7 @@ module array {
     let o: Object = ToObject(context, receiver);
 
     // 2. Let len be ? ToLength(? Get(O, "length")).
-    let len: Number =
-        ToLength_Inline(context, GetProperty(context, o, 'length'));
+    let len: Number = GetLengthProperty(context, o);
 
     // 3. Let relativeStart be ? ToInteger(start).
     let start: Object = arguments[0];

src/builtins/base.tq

@@ -26,7 +26,7 @@ type Code extends AbstractCode generates 'TNode<Code>';
 type JSReceiver extends HeapObject generates 'TNode<JSReceiver>';
 type Context extends HeapObject generates 'TNode<Context>';
 type String extends HeapObject generates
-    'TNode<String>' constexpr 'const char*';
+'TNode<String>' constexpr 'const char*';
 type Oddball extends HeapObject generates 'TNode<Oddball>';
 type HeapNumber extends HeapObject generates 'TNode<HeapNumber>';
 type Number = Smi|HeapNumber;
@@ -69,16 +69,16 @@ type HasPropertyLookupMode constexpr 'HasPropertyLookupMode';
 const NO_ELEMENTS: constexpr ElementsKind generates 'NO_ELEMENTS';
 
 const PACKED_SMI_ELEMENTS: constexpr ElementsKind generates
-    'PACKED_SMI_ELEMENTS';
+'PACKED_SMI_ELEMENTS';
 const HOLEY_SMI_ELEMENTS: constexpr ElementsKind generates 'HOLEY_SMI_ELEMENTS';
 const PACKED_ELEMENTS: constexpr ElementsKind generates 'PACKED_ELEMENTS';
 const HOLEY_ELEMENTS: constexpr ElementsKind generates 'HOLEY_ELEMENTS';
 const PACKED_DOUBLE_ELEMENTS: constexpr ElementsKind generates
-    'PACKED_DOUBLE_ELEMENTS';
+'PACKED_DOUBLE_ELEMENTS';
 const HOLEY_DOUBLE_ELEMENTS: constexpr ElementsKind generates
-    'HOLEY_DOUBLE_ELEMENTS';
+'HOLEY_DOUBLE_ELEMENTS';
 const DICTIONARY_ELEMENTS: constexpr ElementsKind generates
-    'DICTIONARY_ELEMENTS';
+'DICTIONARY_ELEMENTS';
 
 const UINT8_ELEMENTS: constexpr ElementsKind generates 'UINT8_ELEMENTS';
 const INT8_ELEMENTS: constexpr ElementsKind generates 'INT8_ELEMENTS';
@@ -89,7 +89,7 @@ const INT32_ELEMENTS: constexpr ElementsKind generates 'INT32_ELEMENTS';
 const FLOAT32_ELEMENTS: constexpr ElementsKind generates 'FLOAT32_ELEMENTS';
 const FLOAT64_ELEMENTS: constexpr ElementsKind generates 'FLOAT64_ELEMENTS';
 const UINT8_CLAMPED_ELEMENTS: constexpr ElementsKind generates
-    'UINT8_CLAMPED_ELEMENTS';
+'UINT8_CLAMPED_ELEMENTS';
 const BIGUINT64_ELEMENTS: constexpr ElementsKind generates 'BIGUINT64_ELEMENTS';
 const BIGINT64_ELEMENTS: constexpr ElementsKind generates 'BIGINT64_ELEMENTS';
 
@@ -344,7 +344,7 @@ extern macro SmiToInt32(Smi): int32;
 extern macro LoadHeapNumberValue(HeapNumber): float64;
 extern macro ChangeFloat32ToFloat64(float32): float64;
 extern macro ChangeNumberToFloat64(Number): float64;
-extern macro ChangeInt32ToIntPtr(int32): intptr;  // Sign-extends.
+extern macro ChangeInt32ToIntPtr(int32): intptr;   // Sign-extends.
 extern macro ChangeUint32ToWord(uint32): uintptr;  // Doesn't sign-extend.
 
 extern macro NumberConstant(constexpr float64): Number;
@@ -683,13 +683,9 @@ macro NumberIsNaN(number: Number): bool {
 extern macro BranchIfToBooleanIsTrue(Object): never labels Taken, NotTaken;
 
 macro ToBoolean(obj: Object): bool {
-  try {
-    BranchIfToBooleanIsTrue(obj) otherwise Taken, NotTaken;
-  }
-  label Taken {
+  if (BranchIfToBooleanIsTrue(obj)) {
     return true;
-  }
-  label NotTaken {
+  } else {
     return false;
   }
 }

src/code-stub-assembler.h

@@ -296,6 +296,14 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
     return UncheckedCast<JSArray>(heap_object);
   }
 
+  TNode<JSArray> TaggedToFastJSArray(TNode<Context> context,
+                                     TNode<Object> value, Label* fail) {
+    GotoIf(TaggedIsSmi(value), fail);
+    TNode<HeapObject> heap_object = CAST(value);
+    GotoIfNot(IsFastJSArray(heap_object, context), fail);
+    return UncheckedCast<JSArray>(heap_object);
+  }
+
   TNode<JSDataView> TaggedToJSDataView(TNode<Object> value, Label* fail) {
     GotoIf(TaggedIsSmi(value), fail);
     TNode<HeapObject> heap_object = CAST(value);

src/torque/declaration-visitor.h

@@ -24,8 +24,7 @@ class DeclarationVisitor : public FileVisitor {
  public:
   explicit DeclarationVisitor(GlobalContext& global_context)
       : FileVisitor(global_context),
-        scope_(declarations(), global_context.ast()->default_module()) {
-  }
+        scope_(declarations(), global_context.GetDefaultModule()) {}
 
   void Visit(Ast* ast) {
     Visit(ast->default_module());
@@ -38,7 +37,7 @@ class DeclarationVisitor : public FileVisitor {
 
   void Visit(ModuleDeclaration* decl) {
     ScopedModuleActivator activator(this, decl->GetModule());
-    Declarations::NodeScopeActivator scope(declarations(), decl);
+    Declarations::ModuleScopeActivator scope(declarations(), decl->GetModule());
     for (Declaration* child : decl->declarations) Visit(child);
   }
   void Visit(DefaultModuleDeclaration* decl) {
@@ -170,7 +169,7 @@ class DeclarationVisitor : public FileVisitor {
                   const CallableNodeSignature* signature,
                   Statement* body) override;
 
-  Declarations::NodeScopeActivator scope_;
+  Declarations::ModuleScopeActivator scope_;
   std::vector<Builtin*> torque_builtins_;
   std::vector<LiveAndChanged> live_and_changed_variables_;
 };

src/torque/declarations.cc

@@ -9,6 +9,14 @@ namespace v8 {
 namespace internal {
 namespace torque {
 
+Scope* Declarations::GetModuleScope(const Module* module) {
+  auto i = module_scopes_.find(module);
+  if (i != module_scopes_.end()) return i->second;
+  Scope* result = chain_.NewScope();
+  module_scopes_[module] = result;
+  return result;
+}
+
 Scope* Declarations::GetNodeScope(const AstNode* node, bool reset_scope) {
   std::pair<const AstNode*, TypeVector> key(
       node, current_generic_specialization_ == nullptr

src/torque/declarations.h

@@ -116,6 +116,7 @@ class Declarations {
 
   void PrintScopeChain() { chain_.Print(); }
 
+  class ModuleScopeActivator;
   class NodeScopeActivator;
   class CleanNodeScopeActivator;
   class GenericScopeActivator;
@@ -123,6 +124,7 @@ class Declarations {
   class ScopedGenericScopeChainSnapshot;
 
  private:
+  Scope* GetModuleScope(const Module* module);
   Scope* GetNodeScope(const AstNode* node, bool reset_scope = false);
   Scope* GetGenericScope(Generic* generic, const TypeVector& types);
 
@@ -152,6 +154,7 @@ class Declarations {
   Deduplicator<FunctionPointerType> function_pointer_types_;
   Deduplicator<UnionType> union_types_;
   std::vector<std::unique_ptr<Type>> nominal_types_;
+  std::map<const Module*, Scope*> module_scopes_;
   std::map<std::pair<const AstNode*, TypeVector>, Scope*> scopes_;
   std::map<Generic*, ScopeChain::Snapshot> generic_declaration_scopes_;
 };
@@ -165,6 +168,15 @@ class Declarations::NodeScopeActivator {
   Scope::Activator activator_;
 };
 
+class Declarations::ModuleScopeActivator {
+ public:
+  ModuleScopeActivator(Declarations* declarations, const Module* module)
+      : activator_(declarations->GetModuleScope(module)) {}
+
+ private:
+  Scope::Activator activator_;
+};
+
 class Declarations::CleanNodeScopeActivator {
  public:
   CleanNodeScopeActivator(Declarations* declarations, AstNode* node)

src/torque/implementation-visitor.cc

@@ -157,7 +157,7 @@ void ImplementationVisitor::Visit(ModuleDeclaration* decl) {
   Module* module = decl->GetModule();
   Module* saved_module = module_;
   module_ = module;
-  Declarations::NodeScopeActivator scope(declarations(), decl);
+  Declarations::ModuleScopeActivator scope(declarations(), decl->GetModule());
   for (auto& child : decl->declarations) Visit(child);
   module_ = saved_module;
 }

src/torque/types.cc

@@ -162,7 +162,7 @@ void PrintSignature(std::ostream& os, const Signature& sig, bool with_names) {
   os << " labels ";
   for (size_t i = 0; i < sig.labels.size(); ++i) {
     if (i > 0) os << ", ";
-    os << sig.labels[i].name;
+    if (with_names) os << sig.labels[i].name;
 
     if (sig.labels[i].types.size() > 0) os << "(" << sig.labels[i].types << ")";
   }