Add API `mrb_atexit()`.

`mrb_final_mrbgems` will be called as mrb_state atexit function.
Maybe useful in #1844.

include/mruby.h

@@ -102,6 +102,8 @@ enum gc_state {
 
 struct mrb_jmpbuf;
 
+typedef void (*mrb_atexit_func)(struct mrb_state*);
+
 typedef struct mrb_state {
   struct mrb_jmpbuf *jmp;
 
@@ -169,6 +171,9 @@ typedef struct mrb_state {
   struct RClass *eStandardError_class;
 
   void *ud; /* auxiliary data */
+
+  mrb_atexit_func *atexit_stack;
+  mrb_int atexit_stack_len;
 } mrb_state;
 
 #if __STDC_VERSION__ >= 201112L
@@ -413,6 +418,8 @@ void* mrb_pool_realloc(struct mrb_pool*, void*, size_t oldlen, size_t newlen);
 mrb_bool mrb_pool_can_realloc(struct mrb_pool*, void*, size_t);
 void* mrb_alloca(mrb_state *mrb, size_t);
 
+void mrb_atexit(mrb_state *mrb, mrb_atexit_func func);
+
 #ifdef MRB_DEBUG
 #include <assert.h>
 #define mrb_assert(p) assert(p)

src/init.c

@@ -54,11 +54,3 @@ mrb_init_core(mrb_state *mrb)
   mrb_init_mrbgems(mrb); DONE;
 #endif
 }
-
-void
-mrb_final_core(mrb_state *mrb)
-{
-#ifndef DISABLE_GEMS
-  mrb_final_mrbgems(mrb); DONE;
-#endif
-}

src/state.c

@@ -14,7 +14,6 @@
 
 void mrb_init_heap(mrb_state*);
 void mrb_init_core(mrb_state*);
-void mrb_final_core(mrb_state*);
 
 static mrb_value
 inspect_main(mrb_state *mrb, mrb_value mod)
@@ -40,6 +39,7 @@ mrb_open_allocf(mrb_allocf f, void *ud)
   mrb->ud = ud;
   mrb->allocf = f;
   mrb->current_white_part = MRB_GC_WHITE_A;
+  mrb->atexit_stack_len = 0;
 
 #ifndef MRB_GC_FIXED_ARENA
   mrb->arena = (struct RBasic**)mrb_malloc(mrb, sizeof(struct RBasic*)*MRB_GC_ARENA_SIZE);
@@ -221,7 +221,11 @@ mrb_free_context(mrb_state *mrb, struct mrb_context *c)
 void
 mrb_close(mrb_state *mrb)
 {
-  mrb_final_core(mrb);
+  mrb_int i;
+
+  for (i = mrb->atexit_stack_len; i > 0; --i) {
+    mrb->atexit_stack[i - 1](mrb);
+  }
 
   /* free */
   mrb_gc_free_gv(mrb);
@@ -258,3 +262,18 @@ mrb_top_self(mrb_state *mrb)
   }
   return mrb_obj_value(mrb->top_self);
 }
+
+void
+mrb_atexit(mrb_state *mrb, mrb_atexit_func f)
+{
+  size_t stack_size;
+
+  stack_size = sizeof(mrb_atexit_func) * (mrb->atexit_stack_len + 1);
+  if (mrb->atexit_stack_len == 0) {
+    mrb->atexit_stack = (mrb_atexit_func*)mrb_malloc(mrb, stack_size);
+  } else {
+    mrb->atexit_stack = (mrb_atexit_func*)mrb_realloc(mrb, mrb->atexit_stack, stack_size);
+  }
+
+  mrb->atexit_stack[mrb->atexit_stack_len++] = f;
+}

tasks/mrbgems.rake

@@ -26,14 +26,15 @@ MRuby.each_target do
         f.puts %Q[]
         f.puts %Q[#{gems.map{|g| "void GENERATED_TMP_mrb_%s_gem_final(mrb_state* mrb);" % g.funcname}.join("\n")}]
         f.puts %Q[]
-        f.puts %Q[void]
-        f.puts %Q[mrb_init_mrbgems(mrb_state *mrb) {]
-        f.puts %Q[#{gems.map{|g| "GENERATED_TMP_mrb_%s_gem_init(mrb);" % g.funcname}.join("\n")}]
+        f.puts %Q[static void]
+        f.puts %Q[mrb_final_mrbgems(mrb_state *mrb) {]
+        f.puts %Q[#{gems.map{|g| "GENERATED_TMP_mrb_%s_gem_final(mrb);" % g.funcname}.join("\n")}]
         f.puts %Q[}]
         f.puts %Q[]
         f.puts %Q[void]
-        f.puts %Q[mrb_final_mrbgems(mrb_state *mrb) {]
-        f.puts %Q[#{gems.map{|g| "GENERATED_TMP_mrb_%s_gem_final(mrb);" % g.funcname}.join("\n")}]
+        f.puts %Q[mrb_init_mrbgems(mrb_state *mrb) {]
+        f.puts %Q[#{gems.map{|g| "GENERATED_TMP_mrb_%s_gem_init(mrb);" % g.funcname}.join("\n")}]
+        f.puts %Q[mrb_atexit(mrb, mrb_final_mrbgems);]
         f.puts %Q[}]
       end
     end