Fix strict aliasing issue with call to rb_id_table_lookup()

XrXr · web-flow · commit 5c61caa48154 · 2022-04-25T14:30:54.000-04:00
Previously, GCC 11 with -O2 LTO issues -Wmaybe-uninitialized here.
diff --git a/vm_method.c b/vm_method.c
@@ -139,10 +139,11 @@ void rb_clear_constant_cache(void) {}
 void
 rb_clear_constant_cache_for_id(ID id)
 {
+    VALUE lookup_result;
     rb_vm_t *vm = GET_VM();
-    st_table *ics;
 
-    if (rb_id_table_lookup(vm->constant_cache, id, (VALUE *) &ics)) {
+    if (rb_id_table_lookup(vm->constant_cache, id, &lookup_result)) {
+        st_table *ics = (st_table *)lookup_result;
         st_foreach(ics, rb_clear_constant_cache_for_id_i, (st_data_t) NULL);
         ruby_vm_constant_cache_invalidations += ics->num_entries;
     }

Original file line number	Diff line number	Diff line change
`@@ -139,10 +139,11 @@ void rb_clear_constant_cache(void) {}`
`139`	`139`	`void`
`140`	`140`	`rb_clear_constant_cache_for_id(ID id)`
`141`	`141`	`{`
	`142`	`+ VALUE lookup_result;`
`142`	`143`	`rb_vm_t *vm = GET_VM();`
`143`		`- st_table *ics;`
`144`	`144`
`145`		`- if (rb_id_table_lookup(vm->constant_cache, id, (VALUE *) &ics)) {`
	`145`	`+ if (rb_id_table_lookup(vm->constant_cache, id, &lookup_result)) {`
	`146`	`+ st_table ics = (st_table )lookup_result;`
`146`	`147`	`st_foreach(ics, rb_clear_constant_cache_for_id_i, (st_data_t) NULL);`
`147`	`148`	`ruby_vm_constant_cache_invalidations += ics->num_entries;`
`148`	`149`	`}`