[Bug java/44095] New: [4.5/4.6 regression] massive java failures due to -findirect-dispatch breakage on sparc64-linux

["mikpe at it dot uu dot se" <gcc-bugzilla@gcc.gnu.org>]

Java is severely broken on sparc64-linux with gcc 4.5/4.6, which is a major
regression from 4.4:

http://gcc.gnu.org/ml/gcc-testresults/2010-05/msg00853.html (4.6 broken)
http://gcc.gnu.org/ml/gcc-testresults/2010-05/msg00681.html (4.5 broken)
http://gcc.gnu.org/ml/gcc-testresults/2010-05/msg00472.html (4.4 works)

The detailed test suite logs show that _every_ -findirect-dispatch test case
SEGFAULTs shortly after startup.

I've bisected trunk and identified r155622 as the cause:

Author: jakub
Date: Mon Jan  4 16:02:41 2010
New Revision: 155622

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=155622
Log:
        PR driver/42442
        * gcc.c (SWITCH_IGNORE_PERMANENTLY): Define.
        (do_self_spec): For switches with SWITCH_IGNORE set set also
        SWITCH_IGNORE_PERMANENTLY.
        (check_live_switch): Check SWITCH_IGNORE_PERMANENTLY instead
        of SWITCH_IGNORE.

Let's compare installations of r155621 and r155622:

> LD_LIBRARY_PATH=/mnt/scratch/install-r155621/lib: /mnt/scratch/install-r155621/bin/gcj -v -findirect-dispatch --main=ArrayStore2 ArrayStore2.jar
...
 /mnt/scratch/install-r155621/libexec/gcc/sparc64-unknown-linux-gnu/4.5.0/jc1
ArrayStore2.jar -fuse-divide-subroutine -fuse-boehm-gc -fnon-call-exceptions
-fPIC -fkeep-inline-functions -quiet -dumpbase ArrayStore2.jar -mcpu=v8
-auxbase ArrayStore2 -g1 -version -findirect-dispatch
-fbootclasspath=./:/mnt/scratch/install-r155621/share/java/libgcj-4.5.0.jar -o
/tmp/ccCkBmCp.s
...
 as -V -Qy -s -K PIC -32 -relax -o /tmp/ccgzZvpI.o /tmp/ccCkBmCp.s
...

/mnt/scratch/install-r155621/libexec/gcc/sparc64-unknown-linux-gnu/4.5.0/jvgenmain
-findirect-dispatch ArrayStore2main /tmp/ccwLkVQ4.i
...
 /mnt/scratch/install-r155621/libexec/gcc/sparc64-unknown-linux-gnu/4.5.0/cc1
/tmp/ccwLkVQ4.i -quiet -dumpbase ArrayStore2main.c -mcpu=v8 -g1 -version
-fdollars-in-identifiers -o /tmp/ccCkBmCp.s
...
 as -V -Qy -s -32 -relax -o /tmp/cc8Sx4xt.o /tmp/ccCkBmCp.s
...
> LD_LIBRARY_PATH=/mnt/scratch/install-r155621/lib: ./a.out
index
rhs
java.lang.ArrayIndexOutOfBoundsException

> LD_LIBRARY_PATH=/mnt/scratch/install-r155622/lib: /mnt/scratch/install-r155622/bin/gcj -v -findirect-dispatch --main=ArrayStore2 ArrayStore2.jar
...
 /mnt/scratch/install-r155622/libexec/gcc/sparc64-unknown-linux-gnu/4.5.0/jc1
ArrayStore2.jar -fuse-divide-subroutine -fuse-boehm-gc -fnon-call-exceptions
-fPIC -fkeep-inline-functions -quiet -dumpbase ArrayStore2.jar -mcpu=v8
-auxbase ArrayStore2 -g1 -version -findirect-dispatch
-fbootclasspath=./:/mnt/scratch/install-r155622/share/java/libgcj-4.5.0.jar -o
/tmp/cc5XY9sD.s
...
 as -V -Qy -s -K PIC -32 -relax -o /tmp/cc626Pob.o /tmp/cc5XY9sD.s
...

/mnt/scratch/install-r155622/libexec/gcc/sparc64-unknown-linux-gnu/4.5.0/jvgenmain
-findirect-dispatch ArrayStore2main /tmp/ccLsDapM.i
...
 /mnt/scratch/install-r155622/libexec/gcc/sparc64-unknown-linux-gnu/4.5.0/cc1
/tmp/ccLsDapM.i -quiet -dumpbase ArrayStore2main.c -mcpu=v8 -g1 -version
-fdollars-in-identifiers -o /tmp/cc5XY9sD.s
...
 as -V -Qy -s -K PIC -32 -relax -o /tmp/ccw9Ke7n.o /tmp/cc5XY9sD.s
...
> LD_LIBRARY_PATH=/mnt/scratch/install-r155622/lib:. ./a.out
Segmentation fault

The main difference is that in the working compiler, the java classes are
assembled with -K PIC but the generated main() is not, while in the broken
compiler both the java classes and the generated main() are assembled with -K
PIC.  If I force -K PIC with the working compiler it too fails:

> LD_LIBRARY_PATH=/mnt/scratch/install-r155621/lib: /mnt/scratch/install-r155621/bin/gcj -findirect-dispatch --main=ArrayStore2 -Wa,-K,PIC ArrayStore2.jar
> LD_LIBRARY_PATH=/mnt/scratch/install-r155621/lib: ./a.out
Segmentation fault

I note that gcc/java/jvspec.c has %<findirect-dispatch, and that PR42442 is
about correcting the handling of %<match=native.  Clearly something here
doesn't mix well.


-- 
           Summary: [4.5/4.6 regression] massive java failures due to -
                    findirect-dispatch breakage on sparc64-linux
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: java
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mikpe at it dot uu dot se
 GCC build triplet: sparc64-unknown-linux-gnu
  GCC host triplet: sparc64-unknown-linux-gnu
GCC target triplet: sparc64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44095