I've got a bit of a quandry here and would like the advice
of people who are more experienced than I am at C programming
and debugging.
We've got a legacy application that compiles and runs fine
using the following compilers/platforms:
HP-UX 11.23 (PA-RISC) ANSI-C and aC++ C.11.23.04
HP-UX 11.31 (ia64) HP C/aC++ B3910B A.06.23 [May 18, 2009]
Debian "squeeze" i686 gcc-2.95
Here is some debugging output during a runtime parse
of the application's custom scripting language after
compiling with gcc-2.95:
'encountered _endif_; leaving gen_if()
'*cmd->cmd' is '134523664'
' cmd->op' is '200'
' flags' is '0'
' pc' is '200'
'tokenbuf' is 'endif'
' pcptr ' is '155572084'
'*pcptr ' is '0'
' pcptr->code' is '155572068'
'*pcptr->code' is '200'
' pc' is '155572068'
'*pc' is '200'
' pcptr->code->op' is '200'
calling '[while]parse_cmd' in parse_body
in parse_cmd():
'tokenbuf [before tokenize()]' is 'end'
'tokenbuf [after tokenize()]' is 'end'
Database ready 20:53:08
The problem is that gcc-3.X and gcc-4.X compilers generate
code (no matter the optimization level) that fails at
runtime like this:
'encountered _endif_; leaving gen_if()
'*cmd->cmd' is '134523035'
' cmd->op' is '200'
' flags' is '0'
' pc' is '200'
'tokenbuf' is 'endif'
' pcptr ' is '160593780'
'*pcptr ' is '0'
' pcptr->code' is '0'
Segmentation fault
If the bug was a basic programming error, one would expect a
runtime failure (dereferencing a NULL pointer) no matter which
compiler was used. The application compiles cleanly with no
warnings using "-Wall". Were there any transition issues with
the newer gcc compilers of which I may not be aware?
Thanks,
Andris
