Re: Changing Stack Frame in x86...

[Kathy Bieltz <kbieltz at hal-pc dot org>]

Jeffrey,

I'm trying to compile GCC 2.95.3 on RH 7.1 and
my build keeps failing when it trys to make the
./i686-pc-linux-gnu/libiberty directory.

Where did you get the GCC 2.95.3 that you have
running on your RH 7.0 system?

Any pointers you could give to get a working
GCC 2.95.3 on RH 7.1 would be greatly
appreciated.

Thanks!
Kathy Bieltz

"Jeffrey A. Six" wrote:

> I've having some trouble making some modifications to GCC.  I'm compiling
> for the x86 architecture running under RedHat Linux 7.0 using GCC 2.95.3.
> Basically, what I want to do is to modify the stack frame generation so that
> at the beginning of each function, an extra 32 bit value is stored on the
> stack, right next to the return address.  I have modified the function
> prologue and epilogue code generation routines so that this new value is
> pushed onto the stack before the function's stack frame is setup, so that
> this new value is stored right next to the return address.  The epilogue
> pops this new value off right before generating the return instruction.  The
> problem is that this screws up passing parameters into functions, as the
> offsets from %esp generated by the compiler are now wrong since I've pushed
> an extra value onto the stack.  So, basically I need to modify GCC so that
> it "sees" a 8 byte return address instead of a 4 byte return address, as I'm
> pushing this new value next to the return address at the very beginning of
> every function.  I've been playing with the stack frame setup macros in
> i386.h but am not having much luck.  Could someone who is more familiar with
> how to do such a thing in GCC tell me what I have to do to make this happen?
> Thanks...
>
> -j6
>
> -------------------------------------------------------------
> Jeffrey A. Six
>                                    jeffsix@thecouch.ncsc.mil
> US Department of Defense
>
>   "Staff are requested not to use the eye patches in this
>    first-aid kit to impersonate pirates or other characters.
>    They are for medical use only."