On Tue, Feb 28, 2017 at 06:03:05PM +0100, Luc Van Oostenryck wrote:
> On Tue, Feb 28, 2017 at 4:09 PM, Luc Van Oostenryck
> <luc.vanoostenryck@xxxxxxxxx> wrote:
> > There is indeed some problems regarding this, we looked a bit at this
> > some weeks ago. However I firmly believe that the information about
> > the type belong to the operations and not the values.
>
> I've taken a very quick look at this "mt->foo = (void *)0"
> The type info is perfectly present.
> If in sparse-llvm.c:output_op_store() you add somewhere something like:
> fprintf(stderr, "-> %s\n", show_typename(insn->type));
> You will see that it display the expected type: "int *".
> This is all the type info needed: it's the type of insn->target (the
> value to be stored)
> and the type of the dereferencing of insn->src (the (base) address).
>
> The problem is that output_op_store() doesn't use this info, it tries to deduce
> this type via pseudo_to_value() but pseudo_to_value() wrongly assumes that all
> PSEUDO_VALUE-pseudo are integer.
Not very pretty and incomplete but the following patch allow sparse-llvm
to compile this:
struct mytype {
int *foo;
};
extern void init_mytype(struct mytype *mt);
void init_mytype(struct mytype *mt)
{
mt->foo = (int *)mt;
mt->foo = (void *)mt;
mt->foo = (int *)0;
mt->foo = (void *)0;
mt->foo = (void *)(long)0;
}
It fail at " ... = (... *)1;" though.
diff --git a/sparse-llvm.c b/sparse-llvm.c
index 9f362b3ed..9e0450ae7 100644
--- a/sparse-llvm.c
+++ b/sparse-llvm.c
@@ -306,6 +306,7 @@ static void pseudo_name(pseudo_t pseudo, char *buf)
static LLVMValueRef pseudo_to_value(struct function *fn, struct instruction *insn, pseudo_t pseudo)
{
LLVMValueRef result = NULL;
+ LLVMTypeRef type;
switch (pseudo->type) {
case PSEUDO_REG:
@@ -360,7 +361,21 @@ static LLVMValueRef pseudo_to_value(struct function *fn, struct instruction *ins
break;
}
case PSEUDO_VAL:
- result = LLVMConstInt(insn_symbol_type(fn->module, insn), pseudo->value, 1);
+ type = insn_symbol_type(fn->module, insn);
+ switch (LLVMGetTypeKind(type)) {
+ case LLVMPointerTypeKind:
+ assert(!pseudo->value);
+ result = LLVMConstPointerNull(type);
+ break;
+ case LLVMIntegerTypeKind:
+ result = LLVMConstInt(type, pseudo->value, 1);
+ break;
+ default:
+ assert(0);
+ }
break;
case PSEUDO_ARG: {
result = LLVMGetParam(fn->fn, pseudo->nr - 1);
@@ -626,6 +641,7 @@ static void output_op_store(struct function *fn, struct instruction *insn)
addr = calc_memop_addr(fn, insn);
target_in = pseudo_to_value(fn, insn, insn->target);
/* perform store */
--
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