WITH_VAR to reduce same calls

Author: nobu

vm_core.h

@@ -1798,7 +1798,7 @@ extern bool rb_vmdebug_stack_dump_raw(const rb_execution_context_t *ec, const rb
 extern bool rb_vmdebug_debug_print_pre(const rb_execution_context_t *ec, const rb_control_frame_t *cfp, const VALUE *_pc, FILE *);
 extern bool rb_vmdebug_debug_print_post(const rb_execution_context_t *ec, const rb_control_frame_t *cfp, FILE *);
 
-#define SDR() rb_vmdebug_stack_dump_raw(GET_EC(), GET_EC()->cfp, stderr)
+#define SDR() WITH_EC(ec) {rb_vmdebug_stack_dump_raw(ec, ec->cfp, stderr)}
 #define SDR2(cfp) rb_vmdebug_stack_dump_raw(GET_EC(), (cfp), stderr)
 bool rb_vm_bugreport(const void *, FILE *);
 typedef void (*ruby_sighandler_t)(int);
@@ -1916,6 +1916,13 @@ RUBY_EXTERN unsigned int    ruby_vm_event_local_num;
 #define GET_THREAD() rb_current_thread()
 #define GET_EC()     rb_current_execution_context(true)
 
+#define WITH_VAR(type, var, expr) \
+    for (type var = (expr), const *var ## _once = &var; var ## _once; var ## _once = 0)
+#define WITH_VM(var) WITH_VAR(rb_vm_t *, var, GET_VM())
+#define WITH_RACTOR(var) WITH_VAR(rb_ractor_t *, var, GET_RACTOR())
+#define WITH_THREAD(var) WITH_VAR(rb_thread_t *, var, GET_THREAD())
+#define WITH_EC(var) WITH_VAR(rb_execution_context_t *, var, GET_EC())
+
 static inline rb_thread_t *
 rb_ec_thread_ptr(const rb_execution_context_t *ec)
 {