llvm dev - Jul 2009 - [LLVMdev] Stack Management in LLVM

Hi, going through the tutorial (http://llvm.org/docs/tutorial/LangImpl8.html) 
it linked to a post from 2004 
(http://nondot.org/sabre/LLVMNotes/ExplicitlyManagedStackFrames.txt) stating 
that LLVM does not allow explicit stack management.  It also mentioned that 
this was a deficiency in LLVM, leading me to think that there is a 
possibility that things have changed since them.

I'm not just looking to implement garbage collection that may have been done
already in a better way, I will be conducting research into stack handling 
routines for multi-threaded programs.  As such, I will need to have complete 
control over the stack, including the ability to
 
    *  Add memprotected regions before and after stack pages, with the 
intention to catch the interrupt/signal and modify the stack
    * Hook before functions place data on stack, possibly moving the stack 
pointer before data is placed
    * Hook before functions return with explicit control over where the new 
stack pointer will be
    * Ability to resize stack (e.g. on a method call if local variables at the 
end of the stack are dead, new stack will overwrite the dead space)
    * Ability to MOVE stack pages around (yes, I know this requires a language 
that will not allow for pointers to a stack variable)
    * Ability to arbitrarily change the value of the stack pointer 

Are there now explicit stack management hooks in LLVM? Or am I safer staying 
away from LLVM if I need to manage the stack explicitly?  

Thanks for your time, Joshua Moore-Oliva

To the list of modifications I need to be able to perform, add 

the ability to specify the ordering of local variables in the stack
the ability to have one thread access the contents of another thread's
stack.

There may be more I am forgetting, so simply put I need to be able to have 
complete control over the stack.  It's layout, its contents etc.

On Thu, Jul 16, 2009 at 9:29 PM, Joshua
Moore-Oliva<llvm-dev at chatgris.com> wrote:
> To the list of modifications I need to be able to perform, add
>
> the ability to specify the ordering of local variables in the stack
If you need specific locations for everything you're allocating on the
stack, you should probably just use a continuation-passing style like
the one mentioned in
http://nondot.org/sabre/LLVMNotes/ExplicitlyManagedStackFrames.txt ;
LLVM won't preserve the values of variables allocated with alloca
whose address isn't taken.

-Eli