[Bug libgcj/13708] New: java program crashes at startup, UTF-8 environment

[Bug libgcj/13708] New: java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

 

-- 
           Summary: java program crashes at startup, UTF-8 environment
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P1
         Component: libgcj
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mec dot gnu at mindspring dot com
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-16 15:58 -------
(Whoops, hit ENTER way too early!)

The program is:

  public class jmisc
  {
    public static void main (String[] args)
    {
      return;
    }
  }

When I compile and run the program with LANG=en_US, it works fine.
When I compile and run the program with LANG=en_US.UTF-8, it segfaults in
_Jv_FindClass.

This worked with gcc HEAD 2004-01-08.  I will do some date-searching to narrow
it down.  Also, I have a typescript to attach, showing the full stack trace.




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-16 16:00 -------
Created an attachment (id=5501)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=5501&action=view)
typescript showing source code, gcj -v, stack trace of crash

Here is a hunk of the backtrace.

(gdb) backtrace
#0  _Jv_FindClass(_Jv_Utf8Const*, java::lang::ClassLoader*) (name=0x0,
    loader=0x0)
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/natClassLoader.cc:507

#1  0x08070f20 in java::lang::Class::forName(java::lang::String*, bool,
java::lang::ClassLoader*) (className=0x0, initialize=1 '\001', loader=0x0)
    at /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/natClass.cc:81

#2  0x0807102c in java::lang::Class::forName(java::lang::String*) (
    className=0x0)
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/natClass.cc:113
#3  0x080b5e9b in gnu.gcj.convert.UnicodeToBytes.getDefaultEncoder() ()
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/gnu/gcj/convert/UnicodeToBytes.java:49

#4  0x0808c52e in java.io.PrintStream.PrintStream(java.io.OutputStream,
boolean) (this=0x2, out=0x0)
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java:118
#5  0x08084391 in java.lang.System.__U3c_clinit__U3e_() ()
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/System.java:146
#6  0x08070b74 in java::lang::Class::initializeClass() (this=0x81ba0c0)
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/natClass.cc:808
#7  0x08084741 in java.lang.System.getProperty(java.lang.String) (
    key=0x81ba0c0)
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/System.java:405
#8  0x0808716e in java.lang.VMClassLoader.getSystemClassLoader() ()
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/VMClassLoader.java:280

#9  0x0807c1d8 in java.lang.ClassLoader.__U3c_clinit__U3e_() ()
    at
/berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/ClassLoader.java:156


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-16 16:46 -------
I have no problems, are you sure that the compiled program is not picking up the wrong libgcj?

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-16 17:58 -------
Subject: Re:  java program crashes at startup, UTF-8 environment

Well, if the compiled program is pickign up the wrong libgcj, that's
still a bug in gcc HEAD, because I'm installing the compiler and
running it.

But I don't think that's the problem.

I'm running Red Hat Linux 8 with $LANG set to "en_US.UTF-8".
What system and what value of $LANG do you have on your working system?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-16 18:17 -------
I am also running RedHat 8 and I set LANG to be en_US.UTF-8 and it works for me:
tin:~/src/gnu/gcctest>gcj jmisc.java
/usr/lib/crt1.o(.text+0x18): In function `_start':
: undefined reference to `main'
collect2: ld returned 1 exit status
tin:~/src/gnu/gcctest>gcj jmisc.java --main=jmisc
tin:~/src/gnu/gcctest>./a.out
tin:~/src/gnu/gcctest>echo $LANG
en_US.iso885915
tin:~/src/gnu/gcctest>setenv LANG=en_US.UTF-8
tin:~/src/gnu/gcctest>gcj jmisc.java --main=jmisc
tin:~/src/gnu/gcctest>!./
./a.out
tin:~/src/gnu/gcctest>gcj jmisc.java
/usr/lib/crt1.o(.text+0x18): In function `_start':
: undefined reference to `main'
collect2: ld returned 1 exit status
tin:~/src/gnu/gcctest>gcj jmisc.java -C
tin:~/src/gnu/gcctest>gij jmisc

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[tromey at gcc dot gnu dot org]

------- Additional Comments From tromey at gcc dot gnu dot org  2004-01-16 19:27 -------
Frequently a crash like that means your linker is too old.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-16 19:38 -------
This works for me, try a new binutils (which is the liner and the assembler).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |WORKSFORME


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-16 19:53 -------
Subject: Re:  java program crashes at startup, UTF-8 environment

My linker is binutils 2.14, the stock FSF version.

I just tried binutils HEAD 2004-01-15 12:43:56 UTC,
and I get the same problem.

Have a look at my stack trace:

  #0  _Jv_FindClass
  ..
  #8  java.lang.VMClassLoader.getSystemClassLoader
  #9  java.lang.ClassLoader.__U3c_clinit__U3e_

java.lang.ClassLoader is initializing its static 'systemClassLoader'
by calling java.lang.VmClassLoader.getSystemClassLoader.

VmClassLoader.getSystemClassLoader calls
getProperty("java.system.class.loader"), which causes a recursive call
down to _Jv_FindClass("gnu.gcj.convert.Output_UTF8").

_Jv_FindClass finds that Output_UTF8 is not in the cache, and a loader
is not provided.  So it attempts to use getSystemClassLoader, which is
still being initialized, and hence is still null.

I don't understand why this works on Andrew's system, and I haven't
nailed down the gcc patch which caused it to seg fault on my system.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-16 22:01 -------
Subject: Re:  java program crashes at startup, UTF-8 environment

Here is some trace output to help illuminate the problem.
I wrote a simple gdb script, which, ironically, just simulates
printf debugging at some crucial points.

The first trace output is with an executable made with gcc HEAD
2004-01-09 17:10:00 UTC.  In the first trace output, these events occur:

  call _JvCreateJavaVM
  class initialize for java.lang.System
  constructor for java.io.PrintStream
  _Jv_Find_class call on gnu.gcj.convert.Output_UTF8
  initialization of java.lang.VMClassLoader.getSystemClassLoader

The second trace output is with an executable made with gcc HEAD
2004-01-15 13:08:06 UTC.  In the second trace output, these events
occur:

  call _JvCreateJavaVM
  initialization of java.lang.VMClassLoader.getSystemClassLoader
    class initialize for java.lang.System
    constructor for java.io.PrintStream
    _Jv_Find_class call on gnu.gcj.convert.Output_UTF8

In the second version, getSystemClassLoader is initialized early.
getSystemClassLoader uses j.l.System, which constructs an object
of type j.io.PrintStream, which calls _Jv_Find_class on
gnu.gcj.convert.Output_UTF8, which attempts to use the system class
loader ... which is still being initialized ... zero is returned for the
"sys" pointer and a segment fault happens.

(err, I just noticed I have a typo on _Jv_Find_class, sorry about that).

In the first version, j.io.PrintStream gets called before the first call
to getSystemClassLoader.  So when getSystemClassLoader runs for the
first time, it doesn't need to re-enter j.l.System, so it does not
re-enter _Jv_Find_class.

I would be very interested in seeing this output from Andrew's system:

  gdb a.out < findclass.gdbinit

=== trace with gcc HEAD 2004-01-09 17:10:00 UTC

GNU gdb 6.0
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
(gdb) (gdb) (gdb) (gdb) (gdb) (gdb) Breakpoint 1 at 0x804c3d0: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/prims.cc, line 895.
(gdb) >>>>(gdb) (gdb) Breakpoint 2 at 0x80859d1: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/lang/VMClassLoader.java, line 280.
(gdb) >>>>(gdb) (gdb) Breakpoint 3 at 0x8085a90: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/lang/VMClassLoader.java, line 300.
(gdb) >>>>(gdb) (gdb) Breakpoint 4 at 0x80829ee: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/lang/System.java, line 78.
(gdb) >>>>(gdb) (gdb) Breakpoint 5 at 0x808adb6: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java, line 97.
(gdb) >>>>(gdb) (gdb) Breakpoint 6 at 0x808ad99: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java, line 118.
(gdb) >>>>(gdb) (gdb) Breakpoint 7 at 0x808ad4c: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java, line 142.
(gdb) >>>>(gdb) (gdb) Breakpoint 8 at 0x806ff05: file /berman/fsf/shelf/2004-01-09-17-10-00/source/gcc/HEAD/gcc/libjava/java/lang/natClassLoader.cc, line 480.
(gdb) >>>>(gdb) (gdb) Starting program: /berman/home/mec.gnu/gcc/findclass/jmisc.2004-01-09-17-10-00.exe 
[New Thread 8192 (LWP 22233)]
[Switching to Thread 8192 (LWP 22233)]
Current language:  auto; currently c++
break _JvCreateJavaVM
break _Jv_Find_class: java.lang.reflect.Field
Current language:  auto; currently java
break java.lang.System.<clinit>()
Current language:  auto; currently c++
break _Jv_Find_class: java.lang.Object
Current language:  auto; currently java
break java.io.PrintStream.PrintStream(java.io.OutputStream, boolean)
Current language:  auto; currently c++
break _Jv_Find_class: java.lang.Object
break _Jv_Find_class: gnu.gcj.convert.Output_UTF8
break _Jv_Find_class: java.security.Principal
Current language:  auto; currently java
break java.lang.VMClassLoader.getSystemClassLoader
Current language:  auto; currently c++
break _Jv_Find_class: java.net.URL
break _Jv_Find_class: java.lang.Object
break _Jv_Find_class: java.lang.String
break _Jv_Find_class: java.io.File
Current language:  auto; currently java
break java.lang.VMClassLoader.getSystemClassLoader:300
break java.io.PrintStream.PrintStream(java.io.OutputStream, boolean)
Current language:  auto; currently c++
break _Jv_Find_class: gnu.gcj.convert.Output_UTF8
[New Thread 16385 (LWP 22563)]
[New Thread 8194 (LWP 22564)]
break _Jv_Find_class: java.lang.String
break _Jv_Find_class: java.lang.Object
break _Jv_Find_class: java.lang.String
break _Jv_Find_class: java.lang.Object

Program exited normally.
(gdb) 

=== trace with gcc HEAD 2004-01-15 13:08:06 UTC

GNU gdb 6.0
Copyright 2003 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
(gdb) (gdb) (gdb) (gdb) (gdb) (gdb) Breakpoint 1 at 0x804c3e0: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/prims.cc, line 895.
(gdb) >>>>(gdb) (gdb) Breakpoint 2 at 0x8087161: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/VMClassLoader.java, line 280.
(gdb) >>>>(gdb) (gdb) Breakpoint 3 at 0x8087220: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/VMClassLoader.java, line 300.
(gdb) >>>>(gdb) (gdb) Breakpoint 4 at 0x808417e: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/System.java, line 78.
(gdb) >>>>(gdb) (gdb) Breakpoint 5 at 0x808c546: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java, line 97.
(gdb) >>>>(gdb) (gdb) Breakpoint 6 at 0x808c529: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java, line 118.
(gdb) >>>>(gdb) (gdb) Breakpoint 7 at 0x808c4dc: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/io/PrintStream.java, line 142.
(gdb) >>>>(gdb) (gdb) Breakpoint 8 at 0x8071675: file /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/natClassLoader.cc, line 481.
(gdb) >>>>(gdb) (gdb) Starting program: /berman/home/mec.gnu/gcc/findclass/jmisc.today.exe 
[New Thread 8192 (LWP 32363)]
[Switching to Thread 8192 (LWP 32363)]
Current language:  auto; currently c++
break _JvCreateJavaVM
break _Jv_Find_class: java.lang.reflect.Field
break _Jv_Find_class: java.security.Principal
Current language:  auto; currently java
break java.lang.VMClassLoader.getSystemClassLoader
break java.lang.System.<clinit>()
Current language:  auto; currently c++
break _Jv_Find_class: java.lang.Object
Current language:  auto; currently java
break java.io.PrintStream.PrintStream(java.io.OutputStream, boolean)
Current language:  auto; currently c++
break _Jv_Find_class: gnu.gcj.convert.UnicodeToBytes
break _Jv_Find_class: java.lang.Object
break _Jv_Find_class: gnu.gcj.convert.Output_UTF8

Program received signal SIGSEGV, Segmentation fault.
_Jv_FindClass(_Jv_Utf8Const*, java::lang::ClassLoader*) (name=0x0, loader=0x0) at /berman/fsf/_today_/source/gcc/HEAD/gcc/libjava/java/lang/natClassLoader.cc:507
507		  klass = sys->loadClass (sname, false); 
(gdb) 

=== findclass.gdbinit

set height 0
set width 0

delete

break _Jv_CreateJavaVM
commands
silent
printf "break _JvCreateJavaVM\n"
continue
end

break 'java.lang.VMClassLoader.getSystemClassLoader()'
commands
silent
printf "break java.lang.VMClassLoader.getSystemClassLoader\n"
continue
end

break VMClassLoader.java:300
commands
silent
printf "break java.lang.VMClassLoader.getSystemClassLoader:300\n"
continue
end

break 'java.lang.System.<clinit>()'
commands
silent
printf "break java.lang.System.<clinit>()\n"
continue
end

break 'java.io.PrintStream.PrintStream(java.io.OutputStream)'
commands
silent
printf "break java.io.PrintStream.PrintStream(java.io.OutputStream)\n"
continue
end

break 'java.io.PrintStream.PrintStream(java.io.OutputStream, boolean)'
commands
silent
printf "break java.io.PrintStream.PrintStream(java.io.OutputStream, boolean)\n"
continue
end

break 'java.io.PrintStream.PrintStream(java.io.OutputStream, boolean, java.lang.String)'
commands
silent
printf "break java.io.PrintStream.PrintStream(java.io.OutputStream, boolean, java.lang.String)\n"
continue
end

break _Jv_FindClass
commands
silent
printf "break _Jv_Find_class: %s\n", (const char *) name->data
continue
end

run
quit


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[dhazeghi at yahoo dot com]

------- Additional Comments From dhazeghi at yahoo dot com  2004-01-17 00:33 -------
2.14 shouldn't be too old to use...

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|WORKSFORME                  |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-17 10:11 -------
Subject: Re:  java program crashes at startup, UTF-8 environment

Some more info:

Did I mention that I configure my toolchains with --disable-shared?
I bet that's why I encountered the bug and nobody else has.

Try building gcc HEAD with "--disable-shared".  Or just use a normal
toolchain and build the Java executable with "-static".  Both ways
produce the segfault for me.

It appears that the initialization procedure is different for
shared libraries versus unshared archive libraries.

Also, I date-searched the regression to this patch:

  2004-01-14  Nathan Bryant  <nbryant@optonline.net>
	     Tom Tromey  <tromey@redhat.com>

	 PR libgcj/12001:
	 * gnu/gcj/runtime/VMClassLoader.java (VMClassLoader): Pass empty
	 array to superclass.
	 (init): Changed interface; add URLs here.
	 (initialize): New static method.
	 * prims.cc (_Jv_CreateJavaVM): Initialize ClassLoader here...
	 (_Jv_RunMain): ... not here.

This matches the stack backtraces and the gdb traces that I saw:

  VMClassLoader.getSystemClassLoader calls System.getProperty
  class initialization for System constructs three standard PrintStream's.
  java.io.PrintStream.PrintStream calls Unicode stuff
  Unicode stuff wants to use a class loader

Have a look at _Jv_FindClass.  _Jv_FindClass calls _Jv_FindClassInCache,
which returns a non-null klass if the class has been "loaded"
or "initiated".  With a shared library, I suspect that all the classes
are getting "loaded" or "initiated" at the same time; with a static
library, the class "gnu.gcj.convertOutput_UTF8" is definitely not
"loaded" and not "initiated".  I don't know the meanings of "loaded"
and "initiated" so I can't say more than that.

Anyways, link the program with "-static", and be sure to run with
LANG=en_US.UTF-8, and you ought to see the segfault in _Jv_FindClass.

Michael C


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-18 18:06 -------
I think -static is not supported for gcj at all (or --disable-shared) because ld will not link against 
the needed objects.   I cannot reproduce it with the mainline (3.5) with -static and 9.0 RedHat or a 
7.3 RedHat box.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|java program crashes at     |[3.4/3.5 regression] java
                   |startup, UTF-8 environment  |program crashes at startup,
                   |                            |UTF-8 environment
   Target Milestone|---                         |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-18 20:01 -------
Subject: Re:  [3.4/3.5 regression] java program crashes at startup, UTF-8 environment

--disable-shared has been working fine for me with gcj 3.2, 3.2.1,
3.2.2, 3.2.3, 3.3, 3.3.1, 3.3.2, gcj gcc-3_3-branch, and gcj HEAD
until last week.  I've run my test bed with --disable-shared for
two years and the Java test programs compile and link.

--disable-shared is a documented feature.  If -static and
--disable-shared are not supported for java, can you write that in the
documentation somewhere?

Meanwhile, I'm really puzzled that I see this bug happening so easily,
and you don't.

I've put up my executables here:

  ftp://ftp.shout.net/pub/users/mec/java/jmisc.current.shared.exe
  ftp://ftp.shout.net/pub/users/mec/java/jmisc.current.static.exe
  ftp://ftp.shout.net/pub/users/mec/java/jmisc.java

jmisc.current.static.exe exhibits the crash.
jmisc.current.shared.exe does not crash.

  % LANG=en_US.UTF-8 jmisc.current.static.exe

Can you put up your -static -gdwarf-2 executable somewhere, or directly
mail it to me?  I would like to figure out your executable DOESN'T
crash.  It should be about 10 megabytes long, which is why I didn't just
attach it to the bug report.

Michael C


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-18 20:17 -------
Okay my static program is up on http://www.physics.uc.edu/~pinskia/jmisc.current.pinskia.exe.  I 
could reproduce it with your excutable though but not when under gdb for some reason.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-01-19 00:30 -------
Subject: Re:  [3.4/3.5 regression] java program crashes at startup, UTF-8 environment

jmisc.current.pinskia.exe executes with no segfault on my system.

I figured out the difference between jmisc.current.pinskia.exe and
jmisc.current.static.exe.

===

Short version of the analysis:

  . _Jv_CreateJavaVM calls java.lang.ClassLoader.<clinit>
  . java.lang.ClassLoader.<clinit> calls java.lang.VMClassLoader.getSystemClassLoader
  . java.lang.VMClassLoader.getSystemClassLoader calls System.getProperty
  . java.lang.System.getProperty invokes java.lang.System.<clinit>
  . java.lang.System.<clinit> constructs some java.io.PrintStream objects
  . java.io.PrintStream.PrintStream calls gnu.gcj.convert.UnicodeToBytes.getDefaultEncoder
  . getDefaultEncoder loads a class whose name depends on the
    configuration options of libjava as well as the environment.
  . This class is "gnu.gcj.convert.Output_" + getProperty("file.encoding")
    . In jmisc.current.pinskia.exe:
      . getProperty("file.encoding") is "8859-1".
      . getDefaultEncoder tries to load "gnu.gcj.convert.Output_8859_1".
      . This class is already present in the static-linked executable.
      . Works fine.
    . In jmisc.current.static.exe:
      . getProperty("file.encoding") is "UTF-8".
      . getDefaultEncoder tries to load "gnu.gcj.convert.Output_UTF8".
      . This class is not already present in the static-linked executable.
      . So _Jv_FindClass uses the system class loader to go get it.
      . We are still in java.lang.ClassLoader.<clinit>, remember!
      . So the recursive call to ClassLoader.getSystemClassLoader returns NULL!
      . _Jv_FindClass segfaults on sys->loadClass because sys is NULL!

Here is the difference between Andrew's executable and my executable.
jmisc.current.pinskia.exe was built with a libgcj where the system
property "file.encoding" is statically set to "8859-1".
jmisc.current.static.exe was built with a libgcj where the system
property "file.encoding" is dynamically initialized with a call to
"setlocale", and my "file.encoding" is "UTF-8".  This difference comes
from a configuration check in natRuntime.cc for DEFAULT_FILE_ENCODING.

>From there, it turns out that gnu.gcj.convert.Output_8859_1 is
statically linked into the program, but gnu.gcj.convert.Output_UTF8 is not.
And the unicode code is running inside ClassLoader.<clinit>,
so if it reaches for an output converter that is not already statically
linked, then it dies.

===

Long version of the analysis:

Start with this code in natRuntime.cc in
gcc/libjava/java/lang/natRuntime.cc:

  #if ! defined (DEFAULT_FILE_ENCODING) && defined (HAVE_ICONV) \
      && defined (HAVE_NL_LANGINFO)

  static char *
  file_encoding ()
  {
    setlocale (LC_CTYPE, "");
    char *e = nl_langinfo (CODESET);
    if (e == NULL || *e == '\0')
      e = "8859_1";
    return e;
  }

  #define DEFAULT_FILE_ENCODING file_encoding ()

  #endif

  #ifndef DEFAULT_FILE_ENCODING
  #define DEFAULT_FILE_ENCODING "8859_1"
  #endif

  static char *default_file_encoding = DEFAULT_FILE_ENCODING;

In my executable, jmisc.current.static.exe, the "file_encoding" function
is defined.  There is a global ctor for "default_file_encoding".
The global ctor runs at the right time and initializes
"default_file_encoding" to the string "UTF-8".

In your executable, jmisc.current.pinskia.exe, there is no
"file_encoding" function.  The string "default_file_encoding" is
statically initialized to "8859_1".

Note that this initialization depends on the values of HAVE_ICONV and
HAVE_NL_LANGINFO when gcj was built.

Next, java::lang::Runtime::insertSystemProperties does a simple:

  SET ("file.encoding", default_file_encoding);

Later on, gnu.gcj.convert.UnicodeToBytes gets called.  Breakpoint on
that and do a stack trace.  This is the killer stack trace!  Here is the
stack trace in both executables, jmisc.current.static.exe and
jmisc.current.pinskia.exe.

  #0  gnu.gcj.convert.UnicodeToBytes.getDefaultEncoder
  #1  java.io.PrintStream.PrintStream
  #2  java.lang.System.<clinit>
  #3  java::lang::Class::initializeClass
  #4  java.lang.System.getProperty
  #5  java.lang.VMClassLoader.getSystemClassLoader
  #6  java.lang.ClassLoader.<clinit>
  #7  java::lang::Class::initializeClasss
  #8  _Jv_CreateJavaVM
  #9  _Jv_RunMain
  #10 JvRunMain
  #11 main

See, the runtime is still initializing ClassLoader.<clinit>.
ClassLoader.systemClassLoader is going to be NULL until this
initialization is finished.

ClassLoader.<clinit> has dragged in a bunch of other run-time
initialization.  getSystemClassLoader called get Property, which
initializes System.<clinit>.  System.<clinit> constructs the three
standard streams (standard input, standard output, standard error).
That invokes the Unicode encoder.

UnicodeToBytes.getDefaultEncoder says:

  if (defaultEncoding == null)
    {
      String encoding
	= canonicalize (System.getProperty("file.encoding",
					   "8859_1"));
      String className = "gnu.gcj.convert.Output_" + encoding;
      try
	{
	  Class defaultEncodingClass = Class.forName(className);
	  defaultEncoding = encoding;
	}

In jmisc.current.pinskia.exe, the property "file.encoding" has the
value "8859-1".  className is "gnu.gcj.convert.Output_8859_1".

In my executable, jmisc.current.static.exe, the property "file.encoding"
has the value "UTF-8".  className is "gnu.gcj.convert.Output_UTF8".

Next, getDefaultEncoder calls Class.forName(className).
This gets down to _Jv_FindClass.

Look at _Jv_FindClass (in natClassLoader.cc):

  jclass
  _Jv_FindClass (_Jv_Utf8Const *name, java::lang::ClassLoader *loader)
  {
    jclass klass = _Jv_FindClassInCache (name, loader);

    if (! klass)
      {
	jstring sname = _Jv_NewStringUTF (name->data);

	java::lang::ClassLoader *sys
	  = java::lang::ClassLoader::getSystemClassLoader ();

	if (loader)
	  {
	    ...
	  }
	else
	  {
	    // Load using the bootstrap loader jvmspec 5.3.1.
	    klass = sys->loadClass (sname, false); 

	    // Register that we're an initiating loader.
	    if (klass)
	      _Jv_RegisterInitiatingLoader (klass, 0);
	  }

If klass is in the cache, then _Jv_FindClass is happy and just
returns.

If klass is not in the cache, and loader is NULL (which it is),
then this code attempts to use the system loader.  But the system
loader is NULL because we are still initializing it!  See the stack
trace above.  That causes a segfault on "sys->loadClass (...)".

So what determines whether a class is in the cache?
_Jv_FindClassInCache has two hash tables, "loaded_classes" and
"initiated_classes".  If you break on _Jv_RegisterClassHookDefault,
you can see this stack trace:

  _Jv_RegisterClassHookDefault
  _Jv_RegisterClasses
  frame_dummy
  completed.1

frame_dummy is in gcc/crtstuff.c.  It calls _Jv_RegisterClasses
on __JCR_LIST__ to register all the classes in __JCR_LIST__.
This is simply the list of classes that are linked into the executable.

I dumped all the classes in __JCR_LIST__ in jmisc.current.static.exe.
There are 664 classes.  The classes from gnu.gcj.convert are:

  gnu.gcj.convert.BytesToUnicode
  gnu.gcj.convert.Input_8859_1
  gnu.gcj.convert.Input_iconv
  gnu.gcj.convert.IOConverter
  gnu.gcj.convert.UnicodeToBytes
  gnu.gcj.convert.Output_8859_1
  gnu.gcj.convert.Output_iconv

My executable does not have gnu.gcj.convert.Output_UTF8 linked in.
So when getDefaultEncoder attempts to dynamically load it, it crashes,
because getSystemClassLoader is still being initialized.

Next, let me change the example program slightly:

  import gnu.gcj.convert.*;
  public class j2
  {
    public static void main (String[] args)
    {
      Output_UTF8 foo = new gnu.gcj.convert.Output_UTF8 ();
      return;
    }
  }

This program works!

This code will work if any of these conditions are true:

  The executable is linked with a shared libgcj.so.  I suspect that in a
  shared library, every class is in the __JCR_LIST__ for that library,
  whether it is used or not (how else could it work)?  That is
  jmisc.current.shared.exe.

  The executable is built with a Java that was configured such that
  default_class_name is always "8859_1" instead of dynamically fetched
  from the locale.  That is jmisc.current.pinskia.exe.

  The program contains an explicit reference to the output converter,
  such gnu.gcj.convert.Output_UTF8, or whatever the user will select at
  runtime via the locale environment variables.

=== How To Reproduce This

Make sure that libgcj is built on a system where HAVE_ICONV and
HAVE_NL_LANGINFO are true.  Then build jmisc.exe with -static.
Set $LANG to "en_US.UTF-8" and run the test program.

It would be handy to change the test program to print the value
of java.lang.System.getProperty("file.encoding").

=== How To Fix This

This needs some thought.  ClassLoader.<clinit> wants to run very early.
While this is running, it is restricted to classes that are linked into
the program, either statically or shared.  It can't class-load any
classes.

This is the cycle:

  ClassLoader.<clinit> calls VmClassLoader.getSystemClassLoader
  getSystemClassLoaders calls System.getProperty
  System.getProperty invokes System.<clinit>
  System.<clinit> constructs some new PrintStream's
  PrintStream.PrintStream drags in the unicode stuff
  unicode stuff needs the class loader

We could break this cycle at any of those links.

My first idea is to change VMClassLoader.getSystemClassLoader to use
some low-level function rather than System.getProperty, so that it does
not depend on all of System.<clinit>.  That's a lot of code!

My second idea is to re-organize System so that System.<clinit> is more
light weight and safe to invoke before the class loader has been
initialized.

Another idea is to change UnicodeToBytes.getDefaultEncoder so that it
uses if/else logic rather than calling Class.forName.  getDefaultEncoder
is invoked during class loader initialization, so it has to to work
without using the class loader:

  String encoding = canonicalize (System.getProperty("file.encoding", "8859_1"));
       if (encoding == "8859_1"  ) { return new Output_8859_1  (); }
  else if (encoding == "ASCII"   ) { return new Output_ASCII   (); }
  else if (encoding == "EUCJIS"  ) { return new Output_EUCJIS  (); }
  else if (encoding == "JavaSrc" ) { return new Output_JavaSrc (); }
  else if (encoding == "SJIS"    ) { return new Output_SJIS    (); }
  else if (encoding == "UTF8"    ) { return new Output_UTF8    (); }
  else if (encoding == "iconv"   ) { return new Output_iconv   (); }
  else {
      throw new NoClassDefFoundError (
	"missing default encoding " + encoding " + " (class " +
	className + "not found)";
  }

Yeah, it's ugly.  From my perspective, the ugly part is that so much
code is invoked before the class loader is initialized.

Alternatively, you could declare that "-static" does not work with
libgcj, and libgcj must be a shared library.  It would be nice to have a
better diagnostic than a core dump.  Specifically, if native C++ code is
about to use a NULL system class loader, than throw a diagnostic rather
than dereferencing a NULL pointer.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-01-25 03:19:51
               date|                            |
            Summary|[3.4/3.5 regression] java   |[3.4/3.5 regression] static
                   |program crashes at startup, |java program crashes at
                   |UTF-8 environment           |startup, UTF-8 environment


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-02-29 23:47 -------
Java problems are not showstoppers so I have moded the target milestone to 3.4.1.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4.0                       |3.4.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-01 02:02 -------
Patch here: <http://gcc.gnu.org/ml/gcc-patches/2004-01/msg03355.html>.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch
      Known to fail|                            |3.4.0 3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-18 17:23 -------
*** Bug 14636 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |erwin at klomp dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-03-19 05:04 -------
*** Bug 12908 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |oyvind dot harboe at zylin
                   |                            |dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-06-09 19:27 -------
Tom --

I'm postponing this PR yet again, but this problem is an embarassment.  It's
been reported several times and it makes gcj completely unusable for affected users.

Any chance you could review the patch attached to the PR?

-- Mark

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at gcc dot gnu dot
                   |                            |org
   Target Milestone|3.4.1                       |3.4.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[tromey at gcc dot gnu dot org]

------- Additional Comments From tromey at gcc dot gnu dot org  2004-06-09 19:43 -------
Mark, I looked at this.

This is a longstanding gcj issue.  I hesitate to call it
a problem because, as I see it, static linking with gcj
can't really be made completely robust.  The user will always
need to know something about his application and will have
to explicitly link in classes that are only discovered via
reflection.  This is a general issue affecting not just libgcj
itself but any java library one might link against.

I looked at the patch in question.  It is reasonable enough,
though it still needs a tweak (there is no encoding named
"iconv", that handler is a special case).

I'd prefer not to check it in.  I think that, if it is fixed,
real programs will just run into further problems down the road.
For instance, a statically linked program won't have any
locales compiled in.  This means that java.text.* will work
mysteriously, or perhaps fail, depending on the circumstances.
Likewise for java.util.Calendar.

The fix we ordinarily recommend is to have your program directly
reference the encoders and locales it plans to use.  This is not
very satisfactory, I realize, but static linking isn't fully supported.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-06-09 21:37 -------
Subject: Re:  [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

Okay, if static linking with gcj can't be made robust, then how about we
(1) change the documentation to say that it isn't supported, and (2)
change the code to do something more informative than the current
behavior, which is a null-pointer-dereference on startup?

Michael C


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] [3.4/3.5 regression] static java program crashes at startup, UTF-8 environment

[oyvind dot harboe at zylin dot com]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 460 bytes --]


------- Additional Comments From oyvind dot harboe at zylin dot com  2004-06-10 07:42 -------
>Mark, I looked at this.
>
>This is a longstanding gcj issue.  I hesitate to call it
>a problem because, as I see it, static linking with gcj
>can't really be made completely robust. 

My 2 cents.

- Static linking is one of the unique features of GCJ
- libgcj.dll doesn't exist yet under Windows

Øyvind


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-07-09 21:31 -------
This is not a regression at really, the problem comes from the fact that linker removes the object files 
which are not referenced in which means that the Java classes are removed when they should not be.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[3.4/3.5 regression] static |static java program crashes
                   |java program crashes at     |at startup, UTF-8
                   |startup, UTF-8 environment  |environment
   Target Milestone|3.4.2                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[mec dot gnu at mindspring dot com]

------- Additional Comments From mec dot gnu at mindspring dot com  2004-07-10 03:19 -------
Subject: Re:  static java program crashes at startup, UTF-8 environment

I consider this a regression because the test program works
with gcc 3.3.3 and does not work with gcc 3.4.0 and gcc HEAD.

However, if you don't consider it a regression, okay.

Michael C


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-08-20 07:35 -------
*** Bug 16899 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jari dot korva at iki dot fi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[dtiller at captechventures dot com]

------- Additional Comments From dtiller at captechventures dot com  2004-09-07 18:02 -------
For those of us who use gcj in the embedded arena, having static support is
crucial. Many embedded projects can't use a real JVM for performance or memory
footprint reasons. Making statically-linked executables is ideal for porting
Java code into embedded devices.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-11-13 05:35 -------
*** Bug 18459 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ovidr at users dot
                   |                            |sourceforge dot net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-28 00:30 -------
*** Bug 21793 has been marked as a duplicate of this bug. ***

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[gerrit at gcc dot gnu dot org]

------- Additional Comments From gerrit at gcc dot gnu dot org  2005-05-29 02:09 -------
(In reply to comment #29)
> *** Bug 21793 has been marked as a duplicate of this bug. ***

The same example works with the MinGW version of gcj-3.4.2?

And it works when I set the encoding to ISO-8859-1:

$ /usr/bin/gcj -Dfile.encoding=ISO-8859-1 --main=hello_j hello_j.java -o hello_j

$ ./hello_j
Just another Java hacker,


How do I set the default encoding to ISO-8859-1 when building gcj?

And when will GCC be switched to use >= libtool-1.5.10 and newer automake &
autoconf versions?  Shared libraries are not supported by the antiquated libtool
and friends used by GCC.


Gerrit

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-19 23:04 -------
Static linking can never work correctly with libjava/libgcj/gcj.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |WONTFIX


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-19 23:05 -------
*** Bug 22094 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |snambi at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708

[Bug libgcj/13708] static java program crashes at startup, UTF-8 environment

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-15 21:41 -------
*** Bug 21068 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gruni dot ca at gmail dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13708