I am writing a gcc plugin and am trying to detect if a value assigned by a
function call, is a global variable or not. Unfortunately, all calls to
'is_global_var' with a DECL type are returning false.
My pass executes after alias analysis, and ipa analysis. The
cfun->gimple_df->ipa_pta is set to true, so I know the pta analysis should have
resolved global information.
Plugin code:
if (is_gimple_call(stmt))
{
gimple_debug_bb(stmt);
tree lhs = gimple_call_lhs(stmt);
if (lhs && is_global_var(SSA_NAME_VAR(lhs)))
printf("Global detected\n");
}
Source code (in Go):
package main
type T struct {id int}
var myglobal *T;
func fn() *T {
myglobal = new(T); // Should be detected as global
return myglobal;
}
func main() {
t := fn();
}
Basic Block dump as my plugin code executes for function 'fn':
<bb 2>:
# .MEM_4 = VDEF <.MEM_3(D)>
main.myglobal.13_1 = __go_new_nopointers (4);
# .MEM_5 = VDEF <.MEM_4>
main.myglobal = main.myglobal.13_1;
# VUSE <.MEM_5>
D.186_2 = main.myglobal;
return D.186_2;
Any insight would be helpful.
Thanks!
-Matt
