Re: Java parser throws ArrayIndexOutOfBoundsException if first token leads to syntax error

[Tim Landscheidt]

Akim Demaille <address@hidden> wrote:

>>> [...]
>>>  There is a test for syntax errors on the first token in
>>> tests/java.at, but apparently only in combination with an
>>> "error" token.  I hope fixing it is easier than isolating
>>> it was :-).

>> Nope.  Anyway, attached is the fix.  The test case is a bit
>> non-hackily lengthy, but I did not want to interlace it in
>> the existing suite and subtly break half of them in the
>> process.

> Thanks for this!
> [...]

While the assignment form is somewhere over the ocean, I re-
indented and -wrote the test case a bit to bring it more in
line with the other code and added TABs to the commit mes-
sage.  Is this "ready-to-commit"?

  Also on this topic: Are there useful Emacs tidbits and/or
git hooks to format and check commit messages?

Tim

>From d710c2ae6cbb100186b179eba67aad003402bb07 Mon Sep 17 00:00:00 2001
From: Tim Landscheidt <address@hidden>
Date: Sun, 12 Feb 2012 01:29:41 +0000
Subject: [PATCH] Java: Fix syntax error handling without error token.

        * data/lalr1.java (YYParser::parse): Here.
        * tests/java.at: Add test case.
---
 data/lalr1.java |    2 +-
 tests/java.at   |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 1 deletions(-)

diff --git a/data/lalr1.java b/data/lalr1.java
index 57ff993..a40d6c2 100644
--- a/data/lalr1.java
+++ b/data/lalr1.java
@@ -686,7 +686,7 @@ m4_popdef([b4_at_dollar])])dnl
               }
 
             /* Pop the current state because it cannot handle the error token. 
 */
-            if (yystack.height == 1)
+            if (yystack.height == 0)
               return false;
 
             ]b4_locations_if([yyerrloc = yystack.locationAt (0);])[
diff --git a/tests/java.at b/tests/java.at
index b3e79e9..1c38b7b 100644
--- a/tests/java.at
+++ b/tests/java.at
@@ -781,3 +781,65 @@ AT_CHECK([[$EGREP -v ' */?\*' YYParser.java | grep 
'Position']], [1], [ignore])
 AT_CHECK([[$EGREP -v ' */?\*' YYParser.java | grep 'Location']], [1], [ignore])
 
 AT_CLEANUP
+
+
+# ----------------------------------------------- #
+# Java syntax error handling without error token. #
+# ----------------------------------------------- #
+
+AT_SETUP([Java syntax error handling without error token])
+
+AT_DATA([[YYParser.y]], [[%language "Java"
+
+%code imports {
+  import java.io.IOException;
+}
+
+%code lexer {
+  public void yyerror (String s)
+  {
+    System.err.println (s);
+  }
+
+  public Object getLVal ()
+  {
+    return null;
+  }
+
+  public int yylex () throws IOException
+  {
+    int b = System.in.read ();
+    if (b == -1)
+      return EOF;
+    else
+      return b;
+  }
+}
+
+%code {
+  public static void main (String args []) throws IOException
+  {
+    YYParser p = new YYParser ();
+    p.parse ();
+  }
+}
+%%
+input:
+  '-' '-' '\n'
+;
+]])
+AT_DATA([[input1.txt]], [[--
+]])
+AT_DATA([[input2.txt]], [[-+
+]])
+AT_DATA([[input3.txt]], [[+-
+]])
+AT_BISON_CHECK([[YYParser.y]])
+AT_JAVA_COMPILE([[YYParser.java]])
+AT_JAVA_PARSER_CHECK([[YYParser < input1.txt]], [[0]], [[]], [[]])
+AT_JAVA_PARSER_CHECK([[YYParser < input2.txt]], [[0]], [[]], [[syntax error
+]])
+AT_JAVA_PARSER_CHECK([[YYParser < input3.txt]], [[0]], [[]], [[syntax error
+]])
+
+AT_CLEANUP
-- 
1.6.2.5