[Interpreter]: Add fake support for try/catch/finally.

Adds fake try/catch/finally support hidden behind the flag
--ignition-fake-try-catch.

BUG=v8:4280
LOG=N

Review URL: https://codereview.chromium.org/1402093002

Cr-Commit-Position: refs/heads/master@{#31288}

src/flag-definitions.h

@@ -288,6 +288,8 @@ DEFINE_IMPLICATION(ignition, vector_stores)
 DEFINE_STRING(ignition_filter, "~~", "filter for ignition interpreter")
 DEFINE_STRING(ignition_script_filter, "",
               "script filter for ignition interpreter")
+DEFINE_BOOL(ignition_fake_try_catch, false,
+            "enable fake try-catch-finally blocks in ignition for testing")
 DEFINE_BOOL(print_bytecode, false,
             "print bytecode generated by ignition interpreter")
 DEFINE_BOOL(trace_ignition_codegen, false,

src/interpreter/bytecode-generator.cc

@@ -433,11 +433,20 @@ void BytecodeGenerator::VisitForOfStatement(ForOfStatement* stmt) {
 
 
 void BytecodeGenerator::VisitTryCatchStatement(TryCatchStatement* stmt) {
+  if (FLAG_ignition_fake_try_catch) {
+    Visit(stmt->try_block());
+    return;
+  }
   UNIMPLEMENTED();
 }
 
 
 void BytecodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
+  if (FLAG_ignition_fake_try_catch) {
+    Visit(stmt->try_block());
+    Visit(stmt->finally_block());
+    return;
+  }
   UNIMPLEMENTED();
 }
 

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

@@ -25,6 +25,7 @@ class BytecodeGeneratorHelper {
   BytecodeGeneratorHelper() {
     i::FLAG_vector_stores = true;
     i::FLAG_ignition = true;
+    i::FLAG_ignition_fake_try_catch = true;
     i::FLAG_ignition_filter = StrDup(kFunctionName);
     i::FLAG_always_opt = false;
     i::FLAG_allow_natives_syntax = true;
@@ -2596,6 +2597,79 @@ TEST(TopLevelObjectLiterals) {
   }
 }
 
+
+TEST(TryCatch) {
+  InitializedHandleScope handle_scope;
+  BytecodeGeneratorHelper helper;
+
+  // TODO(rmcilroy): modify tests when we have real try catch support.
+  ExpectedSnippet<int> snippets[] = {
+      {"try { return 1; } catch(e) { return 2; }",
+       0,
+       1,
+       5,
+       {
+           B(LdaSmi8), U8(1),  //
+           B(Return),          //
+           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);
+  }
+}
+
+
+TEST(TryFinally) {
+  InitializedHandleScope handle_scope;
+  BytecodeGeneratorHelper helper;
+
+  // TODO(rmcilroy): modify tests when we have real try finally support.
+  ExpectedSnippet<int> snippets[] = {
+      {"var a = 1; try { a = 2; } finally { a = 3; }",
+       1 * kPointerSize,
+       1,
+       14,
+       {
+           B(LdaSmi8), U8(1),  //
+           B(Star), R(0),      //
+           B(LdaSmi8), U8(2),  //
+           B(Star), R(0),      //
+           B(LdaSmi8), U8(3),  //
+           B(Star), R(0),      //
+           B(LdaUndefined),    //
+           B(Return),          //
+       },
+       0},
+      {"var a = 1; try { a = 2; } catch(e) { a = 20 } finally { a = 3; }",
+       1 * kPointerSize,
+       1,
+       14,
+       {
+           B(LdaSmi8), U8(1),  //
+           B(Star), R(0),      //
+           B(LdaSmi8), U8(2),  //
+           B(Star), R(0),      //
+           B(LdaSmi8), U8(3),  //
+           B(Star), R(0),      //
+           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);
+  }
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8

test/cctest/interpreter/test-interpreter.cc

@@ -65,6 +65,7 @@ class InterpreterTester {
         feedback_vector_(feedback_vector) {
     i::FLAG_vector_stores = true;
     i::FLAG_ignition = true;
+    i::FLAG_ignition_fake_try_catch = true;
     i::FLAG_always_opt = false;
     // Set ignition filter flag via SetFlagsFromString to avoid double-free
     // (or potential leak with StrDup() based on ownership confusion).
@@ -1811,3 +1812,31 @@ TEST(InterpreterLogicalAnd) {
     CHECK(return_value->SameValue(*literals[i].second));
   }
 }
+
+
+TEST(InterpreterTryCatch) {
+  HandleAndZoneScope handles;
+
+  // TODO(rmcilroy): modify tests when we have real try catch support.
+  std::string source(InterpreterTester::SourceForBody(
+      "var a = 1; try { a = a + 1; } catch(e) { a = a + 2; }; return a;"));
+  InterpreterTester tester(handles.main_isolate(), source.c_str());
+  auto callable = tester.GetCallable<>();
+
+  Handle<Object> return_val = callable().ToHandleChecked();
+  CHECK_EQ(Smi::cast(*return_val), Smi::FromInt(2));
+}
+
+
+TEST(InterpreterTryFinally) {
+  HandleAndZoneScope handles;
+
+  // TODO(rmcilroy): modify tests when we have real try finally support.
+  std::string source(InterpreterTester::SourceForBody(
+      "var a = 1; try { a = a + 1; } finally { a = a + 2; }; return a;"));
+  InterpreterTester tester(handles.main_isolate(), source.c_str());
+  auto callable = tester.GetCallable<>();
+
+  Handle<Object> return_val = callable().ToHandleChecked();
+  CHECK_EQ(Smi::cast(*return_val), Smi::FromInt(4));
+}

test/test262/testcfg.py

@@ -129,7 +129,7 @@ class Test262TestSuite(testsuite.TestSuite):
     # support the test262 test harness code.
     flags = testcase.flags
     if '--ignition' in flags:
-      flags += [self.ignition_script_filter]
+      flags += [self.ignition_script_filter, "--ignition-fake-try-catch"]
 
     return (flags + context.mode_flags + self.harness +
             self.GetIncludesForTest(testcase) + ["--harmony"] +