[Interpreter] Implement do expressions.

Implements do expressions for the Ignition.

BUG=v8:4685
LOG=N

Review URL: https://codereview.chromium.org/1632213002

Cr-Commit-Position: refs/heads/master@{#33525}

src/interpreter/bytecode-generator.cc

@@ -1222,7 +1222,8 @@ void BytecodeGenerator::VisitNativeFunctionLiteral(
 
 
 void BytecodeGenerator::VisitDoExpression(DoExpression* expr) {
-  UNIMPLEMENTED();
+  VisitBlock(expr->block());
+  VisitVariableProxy(expr->result());
 }
 
 

test/cctest/compiler/test-run-bytecode-graph-builder.cc

@@ -2426,6 +2426,39 @@ TEST(JumpWithConstantsAndWideConstants) {
   }
 }
 
+TEST(BytecodeGraphBuilderDoExpressions) {
+  bool old_flag = FLAG_harmony_do_expressions;
+  FLAG_harmony_do_expressions = true;
+
+  HandleAndZoneScope scope;
+  Isolate* isolate = scope.main_isolate();
+  Zone* zone = scope.main_zone();
+  Factory* factory = isolate->factory();
+  ExpectedSnippet<0> snippets[] = {
+      {"var a = do {}; return a;", {factory->undefined_value()}},
+      {"var a = do { var x = 100; }; return a;", {factory->undefined_value()}},
+      {"var a = do { var x = 100; }; return a;", {factory->undefined_value()}},
+      {"var a = do { var x = 100; x++; }; return a;",
+       {handle(Smi::FromInt(100), isolate)}},
+      {"var i = 0; for (; i < 5;) { i = do { if (i == 3) { break; }; i + 1; }};"
+       "return i;",
+       {handle(Smi::FromInt(3), isolate)}},
+  };
+
+  for (size_t i = 0; i < arraysize(snippets); i++) {
+    ScopedVector<char> script(1024);
+    SNPrintF(script, "function %s() { %s }\n%s();", kFunctionName,
+             snippets[i].code_snippet, kFunctionName);
+
+    BytecodeGraphTester tester(isolate, zone, script.start());
+    auto callable = tester.GetCallable<>();
+    Handle<Object> return_value = callable().ToHandleChecked();
+    CHECK(return_value->SameValue(*snippets[i].return_value()));
+  }
+
+  FLAG_harmony_do_expressions = old_flag;
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8

test/cctest/interpreter/test-bytecode-generator.cc

@@ -7549,6 +7549,68 @@ TEST(WideRegisters) {
   }
 }
 
+TEST(DoExpression) {
+  bool old_flag = FLAG_harmony_do_expressions;
+  FLAG_harmony_do_expressions = true;
+
+  InitializedHandleScope handle_scope;
+  BytecodeGeneratorHelper helper;
+
+  ExpectedSnippet<const char*> snippets[] = {
+      {"var a = do { }; return a;",
+       2 * kPointerSize,
+       1,
+       5,
+       {
+           B(Ldar), R(0),  //
+           B(Star), R(1),  //
+           B(Return)       //
+       },
+       0},
+      {"var a = do { var x = 100; }; return a;",
+       3 * kPointerSize,
+       1,
+       10,
+       {
+           B(LdaSmi8), U8(100),  //
+           B(Star), R(1),        //
+           B(LdaUndefined),      //
+           B(Star), R(0),        //
+           B(Star), R(2),        //
+           B(Return)             //
+       },
+       0},
+      {"while(true) { var a = 10; a = do { ++a; break; }; a = 20; }",
+       2 * kPointerSize,
+       1,
+       24,
+       {
+           B(LdaSmi8),      U8(10),   //
+           B(Star),         R(1),     //
+           B(ToNumber),               //
+           B(Inc),                    //
+           B(Star),         R(1),     //
+           B(Star),         R(0),     //
+           B(Jump),         U8(12),   //
+           B(Ldar),         R(0),     //
+           B(Star),         R(1),     //
+           B(LdaSmi8),      U8(20),   //
+           B(Star),         R(1),     //
+           B(Jump),         U8(-20),  //
+           B(LdaUndefined),           //
+           B(Return),                 //
+       },
+       0},
+  };
+
+  for (size_t i = 0; i < arraysize(snippets); i++) {
+    Handle<BytecodeArray> bytecode_array =
+        helper.MakeBytecodeForFunctionBody(snippets[i].code_snippet);
+    CheckBytecodeArrayEqual(snippets[i], bytecode_array);
+  }
+  FLAG_harmony_do_expressions = old_flag;
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8

test/cctest/interpreter/test-interpreter.cc

@@ -3825,6 +3825,37 @@ TEST(InterpreterWideParametersSummation) {
 
 // TODO(oth): Test for..in with wide registers.
 
+TEST(InterpreterDoExpression) {
+  bool old_flag = FLAG_harmony_do_expressions;
+  FLAG_harmony_do_expressions = true;
+
+  HandleAndZoneScope handles;
+  i::Isolate* isolate = handles.main_isolate();
+  Factory* factory = isolate->factory();
+
+  std::pair<const char*, Handle<Object>> do_expr[] = {
+      {"var a = do {}; return a;", factory->undefined_value()},
+      {"var a = do { var x = 100; }; return a;", factory->undefined_value()},
+      {"var a = do { var x = 100; }; return a;", factory->undefined_value()},
+      {"var a = do { var x = 100; x++; }; return a;",
+       handle(Smi::FromInt(100), isolate)},
+      {"var i = 0; for (; i < 5;) { i = do { if (i == 3) { break; }; i + 1; }};"
+       "return i;",
+       handle(Smi::FromInt(3), isolate)},
+  };
+
+  for (size_t i = 0; i < arraysize(do_expr); i++) {
+    std::string source(InterpreterTester::SourceForBody(do_expr[i].first));
+    InterpreterTester tester(handles.main_isolate(), source.c_str());
+    auto callable = tester.GetCallable<>();
+
+    Handle<i::Object> return_value = callable().ToHandleChecked();
+    CHECK(return_value->SameValue(*do_expr[i].second));
+  }
+
+  FLAG_harmony_do_expressions = old_flag;
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8