RUBY_TRY_UNUSED_BLOCK_WARNING_STRICT

`RUBY_TRY_UNUSED_BLOCK_WARNING_STRICT=1 ruby ...` will enable
strict check for unused block warning.

This option is only for trial to compare the results so the
envname is not considered well.
Should be removed before Ruby 3.4.0 release.

compile.c

@@ -2006,8 +2006,11 @@ iseq_set_use_block(rb_iseq_t *iseq)
         body->param.flags.use_block = 1;
 
         rb_vm_t *vm = GET_VM();
-        st_data_t key = (st_data_t)rb_intern_str(body->location.label); // String -> ID
-        st_insert(vm->unused_block_warning_table, key, 1);
+
+        if (!vm->unused_block_warning_strict) {
+            st_data_t key = (st_data_t)rb_intern_str(body->location.label); // String -> ID
+            st_insert(vm->unused_block_warning_table, key, 1);
+        }
     }
 }
 

vm.c

@@ -4261,6 +4261,12 @@ Init_BareVM(void)
     vm->constant_cache = rb_id_table_create(0);
     vm->unused_block_warning_table = st_init_numtable();
 
+    // TODO: remove before Ruby 3.4.0 release
+    const char *s = getenv("RUBY_TRY_UNUSED_BLOCK_WARNING_STRICT");
+    if (s && strcmp(s, "1") == 0) {
+        vm->unused_block_warning_strict = true;
+    }
+
     // setup main thread
     th->nt = ZALLOC(struct rb_native_thread);
     th->vm = vm;

vm_core.h

@@ -774,6 +774,7 @@ typedef struct rb_vm_struct {
     struct rb_id_table *negative_cme_table;
     st_table *overloaded_cme_table; // cme -> overloaded_cme
     st_table *unused_block_warning_table;
+    bool unused_block_warning_strict;
 
     // This id table contains a mapping from ID to ICs. It does this with ID
     // keys and nested st_tables as values. The nested tables have ICs as keys

vm_insnhelper.c

@@ -2978,6 +2978,7 @@ warn_unused_block(const rb_callable_method_entry_t *cme, const rb_iseq_t *iseq,
 {
     rb_vm_t *vm = GET_VM();
     st_table *dup_check_table = vm->unused_block_warning_table;
+    st_data_t key;
 
     union {
         VALUE v;
@@ -2989,14 +2990,17 @@ warn_unused_block(const rb_callable_method_entry_t *cme, const rb_iseq_t *iseq,
     };
 
     // relax check
-    st_data_t key = (st_data_t)cme->def->original_id;
+    if (!vm->unused_block_warning_strict) {
+        key = (st_data_t)cme->def->original_id;
 
-    if (st_lookup(dup_check_table, key, NULL)) {
-        return;
+        if (st_lookup(dup_check_table, key, NULL)) {
+            return;
+        }
     }
 
     // strict check
     // make unique key from pc and me->def pointer
+    key = 0;
     for (int i=0; i<SIZEOF_VALUE; i++) {
         // fprintf(stderr, "k1:%3d k2:%3d\n", k1.b[i], k2.b[SIZEOF_VALUE-1-i]);
         key |= (st_data_t)(k1.b[i] ^ k2.b[SIZEOF_VALUE-1-i]) << (8 * i);