Handle "//# sourceURL" comments in the Parser instead of the JS.

src/scanner.cc

 // Copyright 2011 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.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include <cmath>
 
 #include "src/scanner.h"
 
@@ skipping 191 matching lines @@
   Token::RBRACE,       // 0x7d
   Token::BIT_NOT,      // 0x7e
   Token::ILLEGAL
 };
 
 
 Token::Value Scanner::Next() {
   current_ = next_;
   has_line_terminator_before_next_ = false;
   has_multiline_comment_before_next_ = false;
+  has_source_map_comment_ = false;
   if (static_cast<unsigned>(c0_) <= 0x7f) {
     Token::Value token = static_cast<Token::Value>(one_char_tokens[c0_]);
     if (token != Token::ILLEGAL) {
       int pos = source_pos();
       next_.token = token;
       next_.location.beg_pos = pos;
       next_.location.end_pos = pos + 1;
       Advance();
       return current_.token;
     }
@@ skipping 65 matching lines @@
   // stream of input elements for the syntactic grammar (see
   // ECMA-262, section 7.4).
   while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
     Advance();
   }
 
   return Token::WHITESPACE;
 }
 
 
+Token::Value Scanner::SkipSourceMapComment() {
+  Advance();
+  source_map_comment_.Reset();
+  while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
+    source_map_comment_.AddChar(c0_);
+    Advance();
+  }
+  has_source_map_comment_ = true;
+  return Token::WHITESPACE;
+}
+
+
 Token::Value Scanner::SkipMultiLineComment() {
   ASSERT(c0_ == '*');
   Advance();
 
   while (c0_ >= 0) {
     uc32 ch = c0_;
     Advance();
     if (unicode_cache_->IsLineTerminator(ch)) {
       // Following ECMA-262, section 7.4, a comment containing
       // a newline will make the comment count as a line-terminator.
@@ skipping 144 matching lines @@
 
       case '%':
         // % %=
         token = Select('=', Token::ASSIGN_MOD, Token::MOD);
         break;
 
       case '/':
         // /  // /* /=
         Advance();
         if (c0_ == '/') {
-          token = SkipSingleLineComment();
+          Advance();
+          if (c0_ == '@' || c0_ == '#') {
+            Advance();
+            token = SkipSourceMapComment();

[yurys, 2014/06/05 13:55:21]

I believe we should consider only sourceURL that are at the end of file. If
there is something like

function foo(){}
//@ sourceURL = url.js
function bar(){}

we should skip the url as far as I remember.

+          } else {
+            PushBack(c0_);
+            token = SkipSingleLineComment();
+          }
         } else if (c0_ == '*') {
           token = SkipMultiLineComment();
         } else if (c0_ == '=') {
           token = Select(Token::ASSIGN_DIV);
         } else {
           token = Token::DIV;
         }
         break;
 
       case '&':
@@ skipping 614 matching lines @@
       Advance();
     }
   }
   literal.Complete();
 
   next_.location.end_pos = source_pos() - 1;
   return true;
 }
 
 
+Handle<String> Scanner::AllocateInternalizedSourceMapComment(Isolate* isolate) {
+  if (source_map_comment_.is_one_byte()) {
+    return isolate->factory()->InternalizeOneByteString(
+        source_map_comment_.one_byte_literal());
+  } else {
+    return isolate->factory()->InternalizeTwoByteString(
+        source_map_comment_.two_byte_literal());
+  }
+}
+
+
 Handle<String> Scanner::AllocateNextLiteralString(Isolate* isolate,
                                                   PretenureFlag tenured) {
   if (is_next_literal_one_byte()) {
     return isolate->factory()->NewStringFromOneByte(
         next_literal_one_byte_string(), tenured).ToHandleChecked();
   } else {
     return isolate->factory()->NewStringFromTwoByte(
         next_literal_two_byte_string(), tenured).ToHandleChecked();
   }
 }
@@ skipping 165 matching lines @@
     }
     backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
   }
   backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
 
   backing_store_.AddBlock(bytes);
   return backing_store_.EndSequence().start();
 }
 
 } }  // namespace v8::internal