llvm dev - Jun 2015 - [LLVMdev] getAnalysis<DataLayout>() Causing Compilation Error

I’m debugging SAFECode source code files, and in AllocatorInfo.cpp, in the
function getObjectSize(Value* V), the function getAnalysis<DataLayout>()
is called.  I’ve run into this problem before, and the first time I saw it, my
employer recommended I use M.getDataLayout() instead, where M was a reference to
a Module.  However, in getObjectSize(Value* V), there is no Module reference in
the list of parameters.  Is there a way to obtain a Module affiliated with the
Value* argument, which I can then use to call M.getDataLayout?  Is there some
other way I can get the DataLayout reference I need?

Thanks,
Peter Finn

So, this is because AllocatorInfo is an ImmutablePass.

This leaves you having to grab it the hard way:

 If value* is an instruction,

dyn_cast<Instruction>(V)->getModule()->getDataLayout().

if value * is a GlobalValue
/* getParent gives a module here */

dyn_cast<GlobalValue>(V)->getParent()->getDataLayout();

if value * is an argument
/* getParent gives a function, and getParent on the function gives our module */
dyn_cast<Argument>(V)->getParent()->getParent()->getDataLayout();

It may be worth making a helper (or making this consistent in some way
by adding getDataLayout() to Value* and overriding it in subclasses or
something).




On Sun, Jun 21, 2015 at 4:31 PM, Peter Finn <peterdfinn at icloud.com>
wrote:
> I’m debugging SAFECode source code files, and in AllocatorInfo.cpp, in the
function getObjectSize(Value* V), the function getAnalysis<DataLayout>()
is called.  I’ve run into this problem before, and the first time I saw it, my
employer recommended I use M.getDataLayout() instead, where M was a reference to
a Module.  However, in getObjectSize(Value* V), there is no Module reference in
the list of parameters.  Is there a way to obtain a Module affiliated with the
Value* argument, which I can then use to call M.getDataLayout?  Is there some
other way I can get the DataLayout reference I need?
>
> Thanks,
> Peter Finn
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Thank you, but how can I determine whether a given Value* V is an Instruction,
or a GlobalValue, or an Argument?

Peter Finn
> On Jun 21, 2015, at 7:41 PM, Daniel Berlin <dberlin at dberlin.org>
wrote:
> 
> So, this is because AllocatorInfo is an ImmutablePass.
> 
> This leaves you having to grab it the hard way:
> 
> If value* is an instruction,
> 
> dyn_cast<Instruction>(V)->getModule()->getDataLayout().
> 
> if value * is a GlobalValue
> /* getParent gives a module here */
> 
> dyn_cast<GlobalValue>(V)->getParent()->getDataLayout();
> 
> if value * is an argument
> /* getParent gives a function, and getParent on the function gives our
module */
>
dyn_cast<Argument>(V)->getParent()->getParent()->getDataLayout();
> 
> It may be worth making a helper (or making this consistent in some way
> by adding getDataLayout() to Value* and overriding it in subclasses or
> something).
> 
> 
> 
> 
> On Sun, Jun 21, 2015 at 4:31 PM, Peter Finn <peterdfinn at
icloud.com> wrote:
>> I’m debugging SAFECode source code files, and in AllocatorInfo.cpp, in
the function getObjectSize(Value* V), the function
getAnalysis<DataLayout>() is called.  I’ve run into this problem before,
and the first time I saw it, my employer recommended I use M.getDataLayout()
instead, where M was a reference to a Module.  However, in getObjectSize(Value*
V), there is no Module reference in the list of parameters.  Is there a way to
obtain a Module affiliated with the Value* argument, which I can then use to
call M.getDataLayout?  Is there some other way I can get the DataLayout
reference I need?
>> 
>> Thanks,
>> Peter Finn
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev