zahed khurasani <sdzahed@xxxxxxxxx> writes: > I need to build a node that is equivalent to the address of the memory > being derenferenced. > MEM_REF would help with the first parameter. But what about the third parameter? > I would need an ADDR_EXPR for this parameter. However, the code I am using > is failing. > Thanks for the help. I'm not sure I completely understand, but I will say that a POINTER_PLUS_EXPR would be the address equivalent of a MEM_REF. Ian > On Fri, Mar 9, 2012 at 6:04 PM, Ian Lance Taylor <iant@xxxxxxxxxx> wrote: >> zahed khurasani <sdzahed@xxxxxxxxx> writes: >> >>> My check function accepts three parameters: the value being >>> dereferenced, the size of the object and the address in memory. I am >>> using the following two lines to get the third address parameter. >>> >>> addr = build1 (ADDR_EXPR, build_pointer_type (type), t); // t is the >>> ARRAY_REF node >>> fold_convert_loc(location, ptr_type_node, addr); // type case to void * >>> >>> However, this is failing whenever the array_ref contains a >>> non-constant expression, say like a[i+1]. The specific failure is >>> inside the expand_expr_real_1 method in the file expr.c. Looks like >>> such non-constant indices are not allowed at this stage in the >>> compilation (I've inserted the pass just before lowering to RTL >>> happens). >>> >>> My question is, what would be the right way to get the address? I am >>> looking for something that will preferably work for all dereferences >>> like MEM_REF, INDIRECT_REF etc. >> >> ARRAY_REF certainly permits non-constant indices, so I don't think that >> is your problem. >> >> However, MEM_REF is the most general memory reference expression. >> >> Ian
