Newsgroups: comp.lang.c++
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!umich!terminator!pinhead.citi.umich.edu!normanb
From: normanb@pinhead.citi.umich.edu (David R. Richardson)
Subject: C and C++
Message-ID: <1991Mar24.224946.2016@terminator.cc.umich.edu>
Followup-To: normanb@ifs.umich.edu
Sender: usenet@terminator.cc.umich.edu (usenet news)
Reply-To: normanb@ifs.umich.edu
Organization: IFS Project, University of Michigan
Date: Sun, 24 Mar 91 22:49:46 GMT

I am having difficulty with combining C and C++ modules into one
executable.  My project consists of a set of X Windows routines
written in C and a set of logic routines written in C++.  The
X Windows code must call two C++ routines -- GameInit to initialize
the simulator and GameTimer which processes one tick of the game
clock.  These are simple wrapper routines which do nothing more than call the
appropriate C++ code.  They are defined as extern "C".

I am using ATT C++ 2.1 on a Sun Sparcstation 1+.  Everything compiles
and links just fine, but segmentation faults shortly into the run.
I believe the problem occurs the first time a C++ io operation is called.
I am using a simple piece of C code for a test -- all it does is invoke
GameInit followed by GameTimer.  An adb backtrace looks like:

SIGSEGV 11: segmentation violation
stopped at      ___ls__7ostreamFPCc+0xc:        ldsh    [%l6 + 0x30], %l6
$c
___ls__7ostreamFPCc(0xc738,0xc148,0x0,0x0,0x0,0x0) + c
_debugdump__4GameFv(0xe888,0x2,0xe908,0xe918,0x4,0x0) + 1c
___ct__4GameFiN71Ul(0xe888,0x1,0x2,0x3,0xe918,0xe8c8) + 1f8
_GameInit(0x1,0x2,0x3,0x4,0x5,0x2) + 5c
_main(0x1,0xf7fffb24,0xf7fffb2c,0xc000,0x0,0x0) + 3c

Where the first instruction in debugdump is:
        cout << " A New Game context\n" ;

As I understand it, cfront causes the normal main() of a program to first
call a special C++ _main() to do some initialization.  It would appear that
because main() is in code compiled by the C compiler, that _main () routine is
never called and therefore the initialization is never performed.  Is
that true, and if so, what can I do about it?


Please respond via mail, and I will post a summary.


Thanks,
david