Hi Luc, On 27 January 2017 at 20:43, Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> wrote: > To get the type of malloc()'s arg and this is done by calling > pseudo_to_value() with the malloc instruction and the pseudo > for the size (but no info about this pseudo being malloc()'s arg). > LLVMConstInt() is then called with the constant value and the type > is given by calling insn_symbol_type() with the malloc instruction > but again, it's not possible to get the right type without specifying > we try to get the type of the first argument of the called function > and not the type of the result. > I think that there is a problem wherever pseudo_to_value() is being used and the pseudo is an integer constant. Firstly the logic for determining the size of the constant needs to cover all cases and secondly depending upon the context the constant may need to be cast to a pointer. So while the patch you mentioned before tries to solve this for comparison operations, I think that the solution needs to cater for all use cases not just those. The handling of arguments is an example of this. My suggestion is that pseudo_to_value() for PSEUDO_VAL should always return an integer constant of type 'long long' and the caller of pseudo_to_value() should adjust the constant to right size (by truncating or extending) or to pointer type if necessary as the caller has more information. For instance, in the handling of OP_CALL, the function output_op_call() knows when the call is for an argument, etc. Currently pseudo_to_value() tries to work out the integer size, but cannot do this correctly due to lack of information, and also even if it did work out the size, the cast to pointer would be missed I think. Does this make sense? Thanks and Regards Dibyendu -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
