[Mono-dev] Interpreter?

[Andreas Färber]

Hi Paolo,

>> I am stuck with my ppc64 port of the JIT so I was hoping to test the
>> interpreter to see if that works.
>
> Event if the interpreter compiled, it wouldn't work on ppc64.
> It would be better if you detailed the issues you have with the ppc64
> port instead because we could help you with that.
> Thanks!

Due to its size I uploaded my unfinished patch to Bugzilla:
http://bugzilla.ximian.com/show_bug.cgi?id=81455

PATCH:

First, it includes changes to eglib/configure.in to make it compile  
on OS X and adds VPATH support to facilitate compiling for ppc and  
ppc64.
configure.in is patched to define POWERPC or POWERPC64 depending on  
the pointer size (and a workaround fixes building monoburg w/eglib on  
OS X for now).
Next, it reorganizes the ppc-codegen.h (header still needs some  
changes Miguel requested) - instructions are now listed  
alphabetically separated from the mnemonics with additions and  
updates for the 64-bit and 32-bit-only instructions.
Then, the mini and arch ppc files were updated with #ifdefs for ppc64  
doing all kinds of necessary changes. I have some FIXMEs/CHECKMEs in  
there, especially some numeric offsets and alignments are unclear to  
me. This is where I suspect the most issues.
Finally, all occurrences of ppc in the sources were checked and adapted.

CONFIGURATION:

I configure Mono --with-gc=none --with-glib=embedded --with-ikvm- 
native=no while exporting CC="gcc -arch ppc64" (as well as setting  
ACLOCAL_FLAGS, PKG_CONFIG, PKG_CONFIG_PATH, CPPFLAGS, LDFLAGS  
appropriately), using a ppc Mono installation of the same revision  
for bootstrapping. (configuring without GC first to rule that out as  
a source of errors)

TEST ENVIRONMENT AND RESULTS:

Test system was a PowerMac G5 dual-core with OS X v10.4.8/9/10.

The ppc Mono is symlinked from /Library/Mono.framework and used "for  
production" - it works fine with this patch applied as far as I can  
tell. There are no other potentially conflicting Mono installations.

The ppc64 Mono runtime compiles fine. Fixing some earlier bugs it now  
runs like a normal app so I can kill it using Ctrl+C. However, on  
compilation of System.dll using the new mono (or on execution of a  
hello world assembly) it aborts with empty stacktrace:

MONO_PATH="../../class/lib/basic:$MONO_PATH" /Users/andreas/Mono/mono- 
ppc64/mono/runtime/mono-wrapper  ../../class/lib/basic/mcs.exe / 
codepage:65001   -d:NET_1_1 -d:ONLY_1_1 -d:BOOTSTRAP_WITH_OLDLIB - 
debug /noconfig -define:XML_DEP -r:System.Xml.dll -target:library - 
out:System.dll  @System.dll.sources
Stacktrace:

make[8]: *** [../../class/lib/basic/System.dll] Abort trap

$ mono/mini/mono ../../../testassembly.exe
Stacktrace:

Abort trap

According to gdb and some printfs it appeared to enter an infinite  
loop on exception handling during JIT initialization leading to, I  
assume, stack overflow:

$ gdb mono/mini/mono
GNU gdb 6.3.50-20050815 (Apple version gdb-573) (Fri Oct 20 15:54:33  
GMT 2006)
Copyright 2004 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 "powerpc-apple-darwin"...Reading symbols  
for shared libraries ... done

(gdb) run ../../../testassembly.exe
Starting program: /Users/andreas/Mono/mono-ppc64/mono/mono/mini/ 
mono ../../../testassembly.exe
Reading symbols for shared libraries .++ done

Program received signal SIGBUS, Bus error.
0x0000000000000000 in ?? ()
(gdb)


I haven't been able to locate the error(s) for several months now and  
would appreciate any hints that could lead to some more progress.

Thanks,

Andreas