Free everything at shutdown

when the RUBY_FREE_ON_SHUTDOWN environment variable is set, manually free memory at shutdown.

Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
Co-authored-by: Peter Zhu <peter@peterzhu.ca>

internal/cont.h

@@ -22,6 +22,9 @@ void rb_jit_cont_init(void);
 void rb_jit_cont_each_iseq(rb_iseq_callback callback, void *data);
 void rb_jit_cont_finish(void);
 
+/* vm.c */
+void rb_free_shared_fiber_pool(void);
+
 // Copy locals from the current execution to the specified fiber.
 VALUE rb_fiber_inherit_storage(struct rb_execution_context_struct *ec, struct rb_fiber_struct *fiber);
 

internal/encoding.h

@@ -29,4 +29,7 @@ void rb_enc_set_base(const char *name, const char *orig);
 int rb_enc_set_dummy(int index);
 PUREFUNC(int rb_data_is_encoding(VALUE obj));
 
+/* vm.c */
+void rb_free_global_enc_table(void);
+
 #endif /* INTERNAL_ENCODING_H */

internal/error.h

@@ -169,6 +169,9 @@ VALUE rb_syserr_new_path_in(const char *func_name, int n, VALUE path);
 #endif
 RUBY_SYMBOL_EXPORT_END
 
+/* vm.c */
+void rb_free_warning(void);
+
 static inline void
 rb_raise_cstr_i(VALUE etype, VALUE mesg)
 {

internal/random.h

@@ -12,5 +12,6 @@
 
 /* random.c */
 int ruby_fill_random_bytes(void *, size_t, int);
+void rb_free_default_rand_key(void);
 
 #endif /* INTERNAL_RANDOM_H */

internal/symbol.h

@@ -32,6 +32,9 @@ ID rb_make_temporary_id(size_t n);
 void rb_gc_free_dsymbol(VALUE);
 int rb_static_id_valid_p(ID id);
 
+/* vm.c */
+void rb_free_static_symid_str(void);
+
 #if __has_builtin(__builtin_constant_p)
 #define rb_sym_intern_ascii_cstr(ptr) \
     (__builtin_constant_p(ptr) ? \

internal/transcode.h

@@ -17,4 +17,7 @@
 extern VALUE rb_cEncodingConverter;
 size_t rb_econv_memsize(rb_econv_t *);
 
+/* vm.c */
+void rb_free_transcoder_table(void);
+
 #endif /* INTERNAL_TRANSCODE_H */

internal/vm.h

@@ -83,6 +83,11 @@ void rb_check_stack_overflow(void);
 extern uint64_t rb_vm_insns_count;
 #endif
 
+extern bool rb_free_on_exit;
+
+/* miniinit.c and builtin.c */
+void rb_free_loaded_builtin_table(void);
+
 /* vm_insnhelper.c */
 VALUE rb_equal_opt(VALUE obj1, VALUE obj2);
 VALUE rb_eql_opt(VALUE obj1, VALUE obj2);