[Bug java/42143] New: gcj creates "dummy" variables

[Bug java/42143] New: gcj creates "dummy" variables

[kurt at roeckx dot be]

Hi,

When running the libtool regression tests, I get the following error:
gcj -shared  -Wl,--whole-archive ./.libs/liba1.a ./.libs/liba2.a
-Wl,--no-whole-archive     -Wl,-soname -Wl,liba12.so.0 -o .libs/liba12.so.0.0.0
./.libs/liba2.a(A2.o):(.rodata+0x0): multiple definition of `java resource
.dummy'
./.libs/liba1.a(A1.o):(.rodata+0x0): first defined here collect2: ld returned 1
exit status

Looking at liba1.a I see:
Relocation section '.rela.text' at offset 0x1ad0 contains 3 entries:
  Offset          Info           Type           Sym. Value    Sym. Name +
Addend000000000005  002600000004 R_X86_64_PLT32    0000000000000000
_ZN4java4lang6ObjectC1 - 4
000000000023  002300000002 R_X86_64_PC32     0000000000000000 _ZGr8_$_dummy - 4

[...]
Symbol table '.symtab' contains 54 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
[...]
    35: 0000000000000000    16 OBJECT  GLOBAL HIDDEN   11 _ZGr8_$_dummy

There is nothing called "dummy" in the source file.  The source
file is:
public class foo1 {
  public static void main(String[] argv) {
    A1 a1 = new A1();
  }
}

It can also be reproduced with a file that just
has "public class foo1 {}"

I get this error with Debian's 4.3.4-4. The version 4.3.2-2 does not generate
that symbol.  An old build log of libtool with gcj version 4.3.3-3 also does
not show the error.


-- 
           Summary: gcj creates "dummy" variables
           Product: gcc
           Version: 4.3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: java
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kurt at roeckx dot be


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] gcj creates "dummy" variables

[kurt at roeckx dot be]

------- Comment #1 from kurt at roeckx dot be  2009-12-06 16:03 -------
Can someone please take a look at this?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5 Regression] gcj creates "dummy" variables

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2010-02-16 10:34 -------
It works for me with FSF 4.3.4.  You might want to report this to Debian.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Target Milestone|---                         |4.3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5 Regression] gcj creates "dummy" variables

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5 Regression] gcj creates "dummy" variables

[pjames at avtrex dot com]

------- Comment #3 from pjames at avtrex dot com  2010-03-09 21:43 -------
I was able to reproduce in Fedora Core 6 and Fedora Core 11

mipsel-linux-gcc (GCC) 4.3.4 20090326 (prerelease)

I was able to avoid the problem by first compiling my .java files to .class
files, then compiling the .class files to .o files. (compiling straight from
.java to .o introduced the dummy symbol)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5 Regression] gcj creates "dummy" variables

[michele at focuseek dot com]

------- Comment #4 from michele at focuseek dot com  2010-03-10 08:05 -------
Yesterday I filed the suspiciously similar bug 42143 with a really simple test
case that fails on gcc 4.4.3 and used to work with gcc 4.2.2. As I wrote in the
description for that bug I suspect it's actually a duplicate of this bug but I
can't confirm it easily as I don't have binutils sources at hand.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5 Regression] gcj creates "dummy" variables

[michele at focuseek dot com]

------- Comment #5 from michele at focuseek dot com  2010-03-10 08:09 -------
(In reply to comment #4)
> [...] suspiciously similar bug 42143 [...]

I meant bug 43302...


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5/4.6 Regression] gcj creates "dummy" variables

[kurt at roeckx dot be]

------- Comment #6 from kurt at roeckx dot be  2010-04-23 19:49 -------
So can someone please comment on this?


-- 

kurt at roeckx dot be changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |UNCONFIRMED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5/4.6 Regression] gcj creates "dummy" variables

[glarkin at FreeBSD dot org]

------- Comment #7 from glarkin at FreeBSD dot org  2010-05-03 18:36 -------
(In reply to comment #6)
> So can someone please comment on this?
> 

I recently encountered this problem while using gcc/gcj 4.5 with ecj-4.5.jar to
compile the pdftk utility (http://www.accesspdf.com/pdftk/) on FreeBSD.  I
maintain the pdftk port for FreeBSD, and I previously used gcc/gcj 4.2 with
ecj-4.3.jar without any problems.

I found a workaround by patching the pdftk Makefiles like so:

 ##
 # implicit rules for creating A from B

 %.o : %.java
        $(GCJ) $(GCJFLAGS) -c $< -o $@
+       ${OBJCOPY} -L '_ZGr8_$$_dummy' $@

The FreeBSD objcopy command changes the .dummy resource from global scope to
local scope in each .o file.  After doing that, the pdftk link phase succeeded
instead of dying with a ton of "duplicate symbol" errors.

After searching for the source of the duplicate symbol, I think I found it
here:

http://gcc.gnu.org/ml/java-patches/2009-q1/msg00049.html

If the patch included in this message is the source of the duplicate symbol
problem, then I wonder if it could be fixed like so?

String someRandomString = <generate random string>();
ZipEntry entry = new ZipEntry(".dummy" + someRandomString);

Feedback welcome,
Greg Larkin


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glarkin at FreeBSD dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |glarkin at FreeBSD dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143

[Bug java/42143] [4.3/4.4/4.5/4.6 Regression] gcj creates "dummy" variables

[rguenth at gcc dot gnu dot org]

------- Comment #8 from rguenth at gcc dot gnu dot org  2010-05-22 18:13 -------
GCC 4.3.5 is being released, adjusting target milestone.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.3.5                       |4.3.6


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42143