Changeset 69906 in webkit

Timestamp:

Oct 15, 2010 6:50:16 PM (14 years ago)

Author:

oliver@apple.com

Message:

2010-10-15 Oliver Hunt <​oliver@apple.com>

Reviewed by Sam Weinig.

Automatic Semicolon Insertion incorrectly inserts semicolon after break, continue, and return followed by a newline
​https://bugs.webkit.org/show_bug.cgi?id=47762

The old YACC parser depended on the lexer for some classes of semicolon insertion.
The new parser handles ASI entirely on its own so when the lexer inserts a semicolon
on its own the net result is a spurious semicolon in the input stream. This can result
in incorrect parsing in some cases:

if (0)

break

;else {}

Would result in a parse failure as the output from the lexer is essentially

if (0)

break

;;else

So the second semicolon is interpreted as a empty statement, which terminates the if,
making the else an error.

• parser/JSParser.cpp: (JSC::JSParser::parseThrowStatement): Parsing of throw statement was wrong, and only worked due to the weird behaviour in the lexer
• parser/Lexer.cpp: (JSC::Lexer::lex): Remove bogus semicolon insertion from the newline handling

2010-10-15 Oliver Hunt <​oliver@apple.com>

Reviewed by Sam Weinig.

ASI incorrectly inserts semicolon after break, continue, and return followed by a newline
​https://bugs.webkit.org/show_bug.cgi?id=47762

tests for correct ASI following break, continue, and return

• fast/js/break-ASI-expected.txt: Added.
• fast/js/break-ASI.html: Added.
• fast/js/script-tests/break-ASI.js: Added.

Location:

trunk

Files:

• JavaScriptCore/ChangeLog (modified) (1 diff)
• JavaScriptCore/parser/JSParser.cpp (modified) (2 diffs)
• JavaScriptCore/parser/Lexer.cpp (modified) (1 diff)
• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/js/break-ASI-expected.txt (added)
• LayoutTests/fast/js/break-ASI.html (added)
• LayoutTests/fast/js/script-tests/break-ASI.js (added)

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+2010-10-15  Oliver Hunt  <oliver@apple.com>
+
+        Reviewed by Sam Weinig.
+
+        Automatic Semicolon Insertion incorrectly inserts semicolon after break, continue, and return followed by a newline
+        https://bugs.webkit.org/show_bug.cgi?id=47762
+
+        The old YACC parser depended on the lexer for some classes of semicolon insertion.
+        The new parser handles ASI entirely on its own so when the lexer inserts a semicolon
+        on its own the net result is a spurious semicolon in the input stream.  This can result
+        in incorrect parsing in some cases:
+
+        if (0)
+            break
+        ;else {}
+
+        Would result in a parse failure as the output from the lexer is essentially
+
+        if (0)
+             break
+        ;;else
+
+        So the second semicolon is interpreted as a empty statement, which terminates the if,
+        making the else an error.
+
+
+        * parser/JSParser.cpp:
+        (JSC::JSParser::parseThrowStatement):
+          Parsing of throw statement was wrong, and only worked due to the weird behaviour
+          in the lexer
+        * parser/Lexer.cpp:
+        (JSC::Lexer::lex):
+          Remove bogus semicolon insertion from the newline handling
+
 2010-10-15  Nikolas Zimmermann  <nzimmermann@rim.com>
 

trunk/JavaScriptCore/parser/JSParser.cpp

@@ -902 +902 @@
     int startLine = tokenLine();
     next();
+    
+    failIfTrue(autoSemiColon());
 
     TreeExpression expr = parseExpression(context);
@@ -907 +909 @@
     int eEnd = lastTokenEnd();
     int endLine = tokenLine();
-    failIfFalse(autoSemiColon());
 
     return context.createThrowStatement(expr, eStart, eEnd, startLine, endLine);

trunk/JavaScriptCore/parser/Lexer.cpp

@@ -1029 +1029 @@
         m_atLineStart = true;
         m_terminator = true;
-        if (lastTokenWasRestrKeyword()) {
-            token = SEMICOLON;
-            m_delimited = true;
-            goto returnToken;
-        }
         goto start;
     case CharacterInvalid:

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2010-10-15  Oliver Hunt  <oliver@apple.com>
+
+        Reviewed by Sam Weinig.
+
+        ASI incorrectly inserts semicolon after break, continue, and return followed by a newline
+        https://bugs.webkit.org/show_bug.cgi?id=47762
+
+        tests for correct ASI following break, continue, and return
+
+        * fast/js/break-ASI-expected.txt: Added.
+        * fast/js/break-ASI.html: Added.
+        * fast/js/script-tests/break-ASI.js: Added.
+
 2010-10-15  Mihai Parparita  <mihaip@chromium.org>