[LLVMdev] LLVM AllocaInst and StoreInst

[Prakash Premkumar]

Thanks a lot Tim and David.

I really found it useful to compare the instructions in the IR with the C++
Classes.
The error in the above code is

> Value *num = ConstantInt:: get(Type::getInt64Ty(context), aTable.value,
> true);


I should use a 32 bit int as my AllocaInst instrcution uses 32 bit int

Thanks
Prakash


On Mon, Aug 4, 2014 at 6:45 PM, David Jones <djones at xtreme-eda.com> wrote:

> As you may have noticed, although the assertions from the debug+assert
> LLVM build are factually correct, for the purposes of debugging code linked
> against it, it's not all that useful.
>
> I have found it useful to build a wrapper layer around LLVM in my project.
> The primary purpose of the wrapper was to isolate my application from
> changes in the LLVM API, as it seems to be a moving target. However, for
> places where I trigger LLVM's assertions frequently, I have "copied" those
> assertions into my wrapper to do the same checks prior to calling into
> LLVM, and to produce useful diagnostics in the case of failure.
>
> For example, I often get argument mismatches between a function call and
> its definition. So, in my callFunction wrapper, I do the type checks, and
> in the event of failure, I print out:
> - the name of the function being called
> - the position of the argument whose type mismatches
> - the formal and actual types in question.
>
> You can consider doing the same - create a wrapper around your calls into
> LLVM, and add better diagnostics where required.
>
> If there is sufficient interest, I might document better what I did.
>
>
>
> On Mon, Aug 4, 2014 at 8:18 AM, Prakash Premkumar <prakash.prax at gmail.com>
> wrote:
>
>> Hi,
>>
>> I am trying to write a simple interpreter.
>>
>> I am trying to generate LLVM IR for assignment operation. The code for
>> the generation part looks like this
>>
>> llvm::Value* codeGenSymTab(llvm::LLVMContext& context) {
>>>     printf("\n CodeGen SymTab \n");
>>>     Value *num = ConstantInt::get(Type::getInt64Ty(context),
>>> aTable.value, true);
>>>     Value *alloc = new AllocaInst(IntegerType::get(context, 32),
>>> aTable.variableName,entry);
>>>     StoreInst *ptr = new StoreInst(num,alloc,false,entry);
>>> }
>>
>>
>> Here goes the SymTab definition:
>>
>> struct SymTab {
>>      char* variableName;
>>      int value;
>>      llvm::Value* (*codeGen)(llvm::LLVMContext& context);
>> };
>>
>>
>> When I try to execute the output file,I get the following error:
>>
>> Assertion failed: (getOperand(0)->getType() ==
>>> cast<PointerType>(getOperand(1)->getType())->getElementType() && "Ptr must
>>> be a pointer to Val type!"), function AssertOK, file Instructions.cpp, line
>>> 1084.
>>> Abort trap: 6
>>
>>
>> Can you help me resolve it ?
>>
>> Thanks
>> Prakash
>>
>> _______________________________________________
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>>
>>
>
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