[Bug java/19505] New: Java bytecode ICE in except.c remove_unreachable_regions

[Bug java/19505] New: Java bytecode ICE in except.c remove_unreachable_regions

[overholt at redhat dot com]

As per final comment in PR18931, I'm opening a new PR.  For additional comments
and a test case, see comments >= 2005-01-05 23:53 in PR18931.

Using Jakub's gcc4 RPMs from Fedora rawhide (on Fedora Core 3), I'm getting:

gcj4 -O2 -fPIC -fjni -findirect-dispatch -shared -o jsch-0.1.17.so \
jsch-0.1.17.jar

com/jcraft/jsch/ChannelSftp.java: In method
'com.jcraft.jsch.ChannelSftp.ls(java.lang.String)':
com/jcraft/jsch/ChannelSftp.java:0: internal compiler error: in
remove_unreachable_regions, at except.c:694

This does not happen with no -O flag.

gcj4 --version:
gcj4 (GCC) 4.0.0 20041228 (Red Hat 4.0.0-0.17)
target:  i686-pc-linux

File:
http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.team.cvs.ssh2/jsch-0.1.17.jar

A similar error happens with jsch-0.1.16.jar.

-- 
           Summary: Java bytecode ICE in except.c remove_unreachable_regions
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: java
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: overholt at redhat dot com
                CC: gcc-bugs at gcc dot gnu dot org,java-prs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug java/19505] Java bytecode ICE in except.c remove_unreachable_regions

[aph at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |aph at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-01-19 12:11:08
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug java/19505] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|2005-01-19 12:11:08         |2005-01-24 15:24:00
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-24 16:34 -------
Just a little more information.
changing "s = redirect_edge_succ_nodup (e, dest);" to a "return false;" in remove_forwarder_block 
makes this pass so this is a tree optimization problem.  Basically what is happening is that we are 
forwarding two eh regions to one bb which is just wrong.  A better check in remove_forwarder_block is 
needed to better test for this case.  Note this only happens with the java front-end because the java 
front-end produces a goto from two catches without any code before it (which is not wrong).


Making this block 17574 which is the meta-bug for "java" bugs which should be fixed before 4.0 (or are 
just regressions in 4.0).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
OtherBugsDependingO|                            |17574
              nThis|                            |
          Component|java                        |tree-optimization
            Summary|Java bytecode ICE in        |[4.0 Regression] Java
                   |except.c                    |bytecode ICE in except.c
                   |remove_unreachable_regions  |remove_unreachable_regions


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[mckinlay at redhat dot com]

------- Additional Comments From mckinlay at redhat dot com  2005-01-25 15:12 -------
Here's a test case for this bug, copied from PR18931. This will fail when
compiling from bytecode produced by Sun's javac, but not from bytecode produced
by gcj or ecj. 

public class PR19505 {

  public int getByte() 
  {
    return 1;
  }

  public void ls(String p) throws Exception{
    try{
      p.toString();

      int type=getByte();

      if(type!=100){
	throw new Exception("");
      }
      if(type==100) return;
      throw new Exception();
    }
    catch(Exception e){
      throw new Exception("");
    }
  }
}



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[aph at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|aph at gcc dot gnu dot org  |unassigned at gcc dot gnu
                   |                            |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2005-01-25 20:47 -------
(In reply to comment #1)
> Just a little more information.
> changing "s = redirect_edge_succ_nodup (e, dest);" to a "return false;" in
remove_forwarder_block 
> makes this pass so this is a tree optimization problem.  Basically what is
happening is that we are 
> forwarding two eh regions to one bb which is just wrong.  A better check in
remove_forwarder_block is 
> needed to better test for this case.  Note this only happens with the java
front-end because the java 
> front-end produces a goto from two catches without any code before it (which
is not wrong).
> 
> 
> Making this block 17574 which is the meta-bug for "java" bugs which should be
fixed before 4.0 (or are 
> just regressions in 4.0).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kazu at cs dot umass dot edu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[kazu at cs dot umass dot edu]

------- Additional Comments From kazu at cs dot umass dot edu  2005-01-25 21:38 -------
I cannot reproduce this.  How frustrating!

CCing Zdenek because he wrote remove_forwarder_block.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rakdver at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[tromey at gcc dot gnu dot org]

------- Additional Comments From tromey at gcc dot gnu dot org  2005-01-25 23:13 -------
I updated and rebuilt gcc and I was able to see this
with the .class file that is attached to the PR.

opsy. gcj -O2 -fPIC -fjni -findirect-dispatch -c PR19505.class
PR19505.java: In class 'PR19505':
PR19505.java: In method 'PR19505.ls(java.lang.String)':
PR19505.java:0: internal compiler error: in remove_unreachable_regions, at
except.c:694
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
opsy. gcj --version
gcj (GCC) 4.0.0 20050125 (experimental)
[...]

This is x86 Fedora Core 2.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-03-22 16:55 -------
*** Bug 20591 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vektor at dumbterm dot net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-20 22:08 -------
Still happens with the mainline: "4.1.0 20050919".

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2005-06-15 03:12:47         |2005-09-20 22:08:07
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-20 22:19 -------
Note at -O1 I cannot reproduce it but at -O2 I could.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-24 21:31 -------
One more thing, is that this happens only at -O2 and above.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-24 21:31 -------
The problem shows up only in .final_cleanup.
Before:
Eh tree:
   4 catch tree_label:<L8>
   3 try
   2 catch tree_label:<L5>
   1 try

After:
   4 catch tree_label:*LJpc=2041
   3 try
   2 catch tree_label:*LJpc=2041
   1 try



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-24 23:08 -------
I have a patch which dects this earlier and will post it soon.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-24 23:32 -------
I have a very simple work around.  If we could get the eh region from a label/bb, it would make it 
easier.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pinskia at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-25 16:00 -------
The patch is:
Index: tree-cfgcleanup.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/tree-cfgcleanup.c,v
retrieving revision 2.7
diff -u -p -r2.7 tree-cfgcleanup.c
--- tree-cfgcleanup.c	19 Aug 2005 18:52:55 -0000	2.7
+++ tree-cfgcleanup.c	24 Sep 2005 23:30:54 -0000
@@ -392,7 +392,18 @@ remove_forwarder_block (basic_block bb, 
 	    return false;
 	}
     }
-
+  /* Check to make sure that we can remove a forwarder block for eh edges.  */
+  FOR_EACH_EDGE (e, ei, bb->preds)
+    {
+      /* This check is too strong, we should also be checking eh regions
+         but this is much harder.  */
+      if (e->flags & EDGE_EH)
+        {
+	  if (!single_pred_p (dest))
+	    return false;
+	}
+    }
+  
   /* Redirect the edges.  */
   for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
     {


Which I will post after testing.
I posted the checking patch here:
http://gcc.gnu.org/ml/gcc-patches/2005-09/msg01559.html


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[aph at gcc dot gnu dot org]

------- Additional Comments From aph at gcc dot gnu dot org  2005-09-27 17:38 -------
Forget that last comment.  Wrong PR.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505

[Bug tree-optimization/19505] [4.0/4.1 Regression] Java bytecode ICE in except.c remove_unreachable_regions

[aph at gcc dot gnu dot org]

------- Additional Comments From aph at gcc dot gnu dot org  2005-09-27 17:35 -------
We also need http://gcc.gnu.org/ml/java/2005-09/msg00053.html.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19505