Hi all!
I'm taking a couple of minutes (my break of the day), to write a few
words.
---
I've release 1.0.3. The main difference is that I fixed a configure
bug. My test for detecting i*86-*-gnu was flawed and always failed.
This means that on x86/GNU-Linux, the slower direct-threaded engine
was selected for the default build. I added the missing configure
macro call.
Note to porters: If you are porting to a system with a unified
dat/instruction cache (x86 based, for example), you'll want to use the
inline-threaded engine. Search for i*86-*-gnu in configure.ac and add
your architecture to the test.
---
First, a general note. In order to test SableVM on a new platform,
and to be able to trace easily though it using a debugger like gdb, or
better DDD (Data Display Debugger, a wonderful gdb X based front-end),
you sould use the --enable-debugging-features. If you do not want all
the assertion stuff (which is a good idea to keep around in the
beginning), you can use --with=threading=switch. You can get both
versions living together (and more) using the build-many script.
In simpler terms:
$ ./build-many /home/myself/sablevm-binary
Then, you simply debug the "sablevm-debug" binary, which automatically
links with a "gcc -O0" version of the native library.
Of course, you can simply look inside the build-many script, and
extract the commands to build only the components you need.
Do not try to debug using the inline-threaded engine; you won't be
able to step through most bytecode instructions (as they'll be
inlined).
---
It is important to test code ported to new platform with a version of
sablevm that DO NOT use signals for detecting exceptions. The
"sablevm-debug" and "sablevm-nosig" both qualify for such tests. This
is because signals might wronfully catch an otherwize erroneous
condition (e.g. segfault) and transform it into a
NullPointerException. In some cases, the application will catch the
(erroneous) exception and then have an unexpected behavior.
This might well explain the failure on powerpc...
---
To Mark Wielaard,
I've quickly looked at your CAS (comp. and sw.) implementation. I do
not know powerpc assembly, but your code seems relatively ok at fist
sight.
--
To Archie Cobbs
I've compiled the DoublePrint class, and ran it with sablevm (1.0.3)
without any problem. It prints "HelloWorld". Try the sablevm-debug
version. (I've attached the .class file i've compiled [I had lost
yours]).
In case you wanted to see a trace of ALL exceptions thrown inluding
ones that ARE catched (except class loading related ones, which are
usually normal due to class loader delegation), replace the "#ifdef
COMMENT" at the beginning of the exception handling code in
src/libsablevm/interpreter.c by "#ifndef COMMENT". Do not forget to
revert the code once you're done debugging.
---
That's all for today.
Have fun!
Etienne
--
Etienne M. Gagnon http://www.info.uqam.ca/~egagnon/
SableVM: http://www.sablevm.org/
SableCC: http://www.sablecc.org/
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