[LLVMdev] differences in IR and ELF?

[ret val]

Contents of section my_section:
 400890 c3666666 6666662e 0f1f8400 00000000  .ffffff.........
 4008a0 38106000 00000000 b0064000 00000000  8.`....... at .....
 4008b0 d0064000 00000000 0f1f8400 00000000  .. at .............
 4008c0 38106000 00000000 d0064000 00000000  8.`....... at .....
 4008d0 30074000 00000000                    0. at .....


This seems too big and doesn't make sense considering the IR.


On Thu, Nov 24, 2011 at 3:44 AM, James Molloy <james.molloy at arm.com> wrote:
> Hi,
>
> How large is the section? How large should it be? Can you post an objdump
-r
> of it?
>
> Cheers,
>
> James
>
> -----Original Message-----
> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
> Behalf Of ret val
> Sent: 24 November 2011 02:20
> To: llvmdev at cs.uiuc.edu
> Subject: [LLVMdev] differences in IR and ELF?
>
> I'm trying to create a GlobalVariable that is a ConstantArray. Id like
> each element to be a pointer to other things in the program(global
> variables, functions). So that they all have the same type Id like to
> make the elements void pointers.
>
> I think I am going about this wrong, heres how I am doing it:
>
> void writeArray(Module &M, GlobalVariable *shadow, Function *val,
>                      Function *func) {
>               /* Build up contents */
>               vector<Constant *> v_elements;
>               Type *elm_type = Type::getInt32PtrTy(M.getContext());
>
>               Constant *tmp = dyn_cast<Constant>(shadow);
>               assert(tmp != NULL && "shadow");
>               v_elements.push_back(ConstantExpr::getBitCast(tmp,
> elm_type));
>
>               tmp = dyn_cast<Constant>(val);
>               assert(tmp != NULL && "value");
>               v_elements.push_back(ConstantExpr::getBitCast(tmp,
> elm_type));
>
>               tmp = dyn_cast<Constant>(func);
>               assert(tmp != NULL && "function");
>               v_elements.push_back(ConstantExpr::getBitCast(tmp,
> elm_type));
>
>               /* Create array */
>               ArrayRef<Constant *> a_elements(v_elements);
>               ArrayType *type = ArrayType::get(elm_type, 3);
>               Constant *array = ConstantArray::get(type, a_elements);
>
>               /* Make new GlobalVariable from array */
>               GlobalVariable *global = new GlobalVariable(M, type, true,
>
>        my_linkage, array,
>
>        "my array");
>               global->setSection(*my_section);
> }
>
> The IR looks like this:
> @"my array" = constant [3 x i32*] [i32* bitcast (i32 (i32)** @"Shadow
> Variable for ptr1" to i32*), i32* bitcast (i32 (i32)* @f2 to i32*),
> i32* bitcast (i32 (i32)* @f1 to i32*)], section "my_section"
> @"my array2" = constant [3 x i32*] [i32* bitcast (i32 (i32)** @"Shadow
> Variable for ptr1" to i32*), i32* bitcast (i32 (i32)* @f1 to i32*),
> i32* bitcast (i32 ()* @main to i32*)], section "my_section"
>
> The ELF section is too large. It does not look like padding, it looks
> like more are being created and I don't know why.
> _______________________________________________
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>
>
>
>
>
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