Move compilation error handling into a separate class.

In addition to Parser, other phases (such as scope analysis) need to handle
compilation errors in the future. PendingCompilationErrorHandled takes care of
error handling in a unified way.

Split from https://codereview.chromium.org/943543002/ .

R=rossberg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/960543002

Cr-Commit-Position: refs/heads/master@{#26853}

BUILD.gn

@@ -859,6 +859,8 @@ source_set("v8_base") {
     "src/ostreams.h",
     "src/parser.cc",
     "src/parser.h",
+    "src/pending-compilation-error-handler.cc",
+    "src/pending-compilation-error-handler.h",
     "src/perf-jit.cc",
     "src/perf-jit.h",
     "src/preparse-data-format.h",

src/parser.cc

@@ -608,12 +608,9 @@ void ParserTraits::ReportMessageAt(Scanner::Location source_location,
     // and we want to report the stack overflow later.
     return;
   }
-  parser_->has_pending_error_ = true;
-  parser_->pending_error_location_ = source_location;
-  parser_->pending_error_message_ = message;
-  parser_->pending_error_char_arg_ = arg;
-  parser_->pending_error_arg_ = NULL;
-  parser_->pending_error_type_ = error_type;
+  parser_->pending_error_handler_.ReportMessageAt(source_location.beg_pos,
+                                                  source_location.end_pos,
+                                                  message, arg, error_type);
 }
 
 
@@ -640,12 +637,9 @@ void ParserTraits::ReportMessageAt(Scanner::Location source_location,
     // and we want to report the stack overflow later.
     return;
   }
-  parser_->has_pending_error_ = true;
-  parser_->pending_error_location_ = source_location;
-  parser_->pending_error_message_ = message;
-  parser_->pending_error_char_arg_ = NULL;
-  parser_->pending_error_arg_ = arg;
-  parser_->pending_error_type_ = error_type;
+  parser_->pending_error_handler_.ReportMessageAt(source_location.beg_pos,
+                                                  source_location.end_pos,
+                                                  message, arg, error_type);
 }
 
 
@@ -789,11 +783,6 @@ Parser::Parser(CompilationInfo* info, uintptr_t stack_limit, uint32_t hash_seed,
       compile_options_(info->compile_options()),
       cached_parse_data_(NULL),
       parsing_lazy_arrow_parameters_(false),
-      has_pending_error_(false),
-      pending_error_message_(NULL),
-      pending_error_arg_(NULL),
-      pending_error_char_arg_(NULL),
-      pending_error_type_(kSyntaxError),
       total_preparse_skipped_(0),
       pre_parse_timer_(NULL),
       parsing_on_main_thread_(true) {
@@ -4283,57 +4272,6 @@ void Parser::HandleSourceURLComments(Isolate* isolate, Handle<Script> script) {
 }
 
 
-void Parser::ThrowPendingError(Isolate* isolate, Handle<Script> script) {
-  DCHECK(ast_value_factory()->IsInternalized());
-  if (has_pending_error_) {
-    MessageLocation location(script, pending_error_location_.beg_pos,
-                             pending_error_location_.end_pos);
-    Factory* factory = isolate->factory();
-    bool has_arg =
-        pending_error_arg_ != NULL || pending_error_char_arg_ != NULL;
-    Handle<FixedArray> elements = factory->NewFixedArray(has_arg ? 1 : 0);
-    if (pending_error_arg_ != NULL) {
-      Handle<String> arg_string = pending_error_arg_->string();
-      elements->set(0, *arg_string);
-    } else if (pending_error_char_arg_ != NULL) {
-      Handle<String> arg_string =
-          factory->NewStringFromUtf8(CStrVector(pending_error_char_arg_))
-          .ToHandleChecked();
-      elements->set(0, *arg_string);
-    }
-    isolate->debug()->OnCompileError(script);
-
-    Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
-    Handle<Object> error;
-    switch (pending_error_type_) {
-      case kReferenceError:
-        error = factory->NewReferenceError(pending_error_message_, array);
-        break;
-      case kSyntaxError:
-        error = factory->NewSyntaxError(pending_error_message_, array);
-        break;
-    }
-
-    Handle<JSObject> jserror = Handle<JSObject>::cast(error);
-
-    Handle<Name> key_start_pos = factory->error_start_pos_symbol();
-    JSObject::SetProperty(jserror, key_start_pos,
-                          handle(Smi::FromInt(location.start_pos()), isolate),
-                          SLOPPY).Check();
-
-    Handle<Name> key_end_pos = factory->error_end_pos_symbol();
-    JSObject::SetProperty(jserror, key_end_pos,
-                          handle(Smi::FromInt(location.end_pos()), isolate),
-                          SLOPPY).Check();
-
-    Handle<Name> key_script = factory->error_script_symbol();
-    JSObject::SetProperty(jserror, key_script, script, SLOPPY).Check();
-
-    isolate->Throw(*error, &location);
-  }
-}
-
-
 void Parser::Internalize(Isolate* isolate, Handle<Script> script, bool error) {
   // Internalize strings.
   ast_value_factory()->Internalize(isolate);
@@ -4343,7 +4281,8 @@ void Parser::Internalize(Isolate* isolate, Handle<Script> script, bool error) {
     if (stack_overflow()) {
       isolate->StackOverflow();
     } else {
-      ThrowPendingError(isolate, script);
+      DCHECK(pending_error_handler_.has_pending_error());
+      pending_error_handler_.ThrowPendingError(isolate, script);
     }
   }
 

src/parser.h

@@ -8,6 +8,7 @@
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/compiler.h"  // For CachedDataMode
+#include "src/pending-compilation-error-handler.h"
 #include "src/preparse-data.h"
 #include "src/preparse-data-format.h"
 #include "src/preparser.h"
@@ -843,13 +844,7 @@ class Parser : public ParserBase<ParserTraits> {
 
   bool parsing_lazy_arrow_parameters_;  // for lazily parsed arrow functions.
 
-  // Pending errors.
-  bool has_pending_error_;
-  Scanner::Location pending_error_location_;
-  const char* pending_error_message_;
-  const AstRawString* pending_error_arg_;
-  const char* pending_error_char_arg_;
-  ParseErrorType pending_error_type_;
+  PendingCompilationErrorHandler pending_error_handler_;
 
   // Other information which will be stored in Parser and moved to Isolate after
   // parsing.

src/pending-compilation-error-handler.cc

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/pending-compilation-error-handler.h"
+
+#include "src/debug.h"
+#include "src/handles.h"
+#include "src/isolate.h"
+#include "src/messages.h"
+
+namespace v8 {
+namespace internal {
+
+void PendingCompilationErrorHandler::ThrowPendingError(Isolate* isolate,
+                                                       Handle<Script> script) {
+  if (!has_pending_error_) return;
+  MessageLocation location(script, start_position_, end_position_);
+  Factory* factory = isolate->factory();
+  bool has_arg = arg_ != NULL || char_arg_ != NULL;
+  Handle<FixedArray> elements = factory->NewFixedArray(has_arg ? 1 : 0);
+  if (arg_ != NULL) {
+    Handle<String> arg_string = arg_->string();
+    elements->set(0, *arg_string);
+  } else if (char_arg_ != NULL) {
+    Handle<String> arg_string =
+        factory->NewStringFromUtf8(CStrVector(char_arg_)).ToHandleChecked();
+    elements->set(0, *arg_string);
+  }
+  isolate->debug()->OnCompileError(script);
+
+  Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
+  Handle<Object> error;
+
+  switch (error_type_) {
+    case kReferenceError:
+      error = factory->NewReferenceError(message_, array);
+      break;
+    case kSyntaxError:
+      error = factory->NewSyntaxError(message_, array);
+      break;
+  }
+
+  Handle<JSObject> jserror = Handle<JSObject>::cast(error);
+
+  Handle<Name> key_start_pos = factory->error_start_pos_symbol();
+  JSObject::SetProperty(jserror, key_start_pos,
+                        handle(Smi::FromInt(location.start_pos()), isolate),
+                        SLOPPY).Check();
+
+  Handle<Name> key_end_pos = factory->error_end_pos_symbol();
+  JSObject::SetProperty(jserror, key_end_pos,
+                        handle(Smi::FromInt(location.end_pos()), isolate),
+                        SLOPPY).Check();
+
+  Handle<Name> key_script = factory->error_script_symbol();
+  JSObject::SetProperty(jserror, key_script, script, SLOPPY).Check();
+
+  isolate->Throw(*error, &location);
+}
+}
+}  // namespace v8::internal

src/pending-compilation-error-handler.h

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_PENDING_COMPILATION_ERROR_HANDLER_H_
+#define V8_PENDING_COMPILATION_ERROR_HANDLER_H_
+
+#include "src/base/macros.h"
+#include "src/globals.h"
+
+namespace v8 {
+namespace internal {
+
+class AstRawString;
+template <class T>
+class Handle;
+class Isolate;
+class Script;
+
+// Helper class for handling pending compilation errors consistently in various
+// compilation phases.
+class PendingCompilationErrorHandler {
+ public:
+  PendingCompilationErrorHandler()
+      : has_pending_error_(false),
+        start_position_(-1),
+        end_position_(-1),
+        message_(nullptr),
+        arg_(nullptr),
+        char_arg_(nullptr),
+        error_type_(kSyntaxError) {}
+
+  void ReportMessageAt(int start_position, int end_position,
+                       const char* message, const char* arg = nullptr,
+                       ParseErrorType error_type = kSyntaxError) {
+    if (has_pending_error_) return;
+    has_pending_error_ = true;
+    start_position_ = start_position;
+    end_position_ = end_position;
+    message_ = message;
+    char_arg_ = arg;
+    arg_ = nullptr;
+    error_type_ = error_type;
+  }
+
+  void ReportMessageAt(int start_position, int end_position,
+                       const char* message, const AstRawString* arg,
+                       ParseErrorType error_type = kSyntaxError) {
+    if (has_pending_error_) return;
+    has_pending_error_ = true;
+    start_position_ = start_position;
+    end_position_ = end_position;
+    message_ = message;
+    char_arg_ = nullptr;
+    arg_ = arg;
+    error_type_ = error_type;
+  }
+
+  bool has_pending_error() const { return has_pending_error_; }
+
+  void ThrowPendingError(Isolate* isolate, Handle<Script> script);
+
+ private:
+  bool has_pending_error_;
+  int start_position_;
+  int end_position_;
+  const char* message_;
+  const AstRawString* arg_;
+  const char* char_arg_;
+  ParseErrorType error_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(PendingCompilationErrorHandler);
+};
+
+}  // namespace internal
+}  // namespace v8
+#endif  // V8_PENDING_COMPILATION_ERROR_HANDLER_H_

tools/gyp/v8.gyp

@@ -767,6 +767,8 @@
         '../../src/ostreams.h',
         '../../src/parser.cc',
         '../../src/parser.h',
+        '../../src/pending-compilation-error-handler.cc',
+        '../../src/pending-compilation-error-handler.h',
         '../../src/perf-jit.cc',
         '../../src/perf-jit.h',
         '../../src/preparse-data-format.h',