Shrink file name table size to `uint16_t`; ref #4138

2 files changed, 8 insertions, 4 deletions

diff --git a/include/mruby/compile.h b/include/mruby/compile.h
index a85460415..63ec8aca1 100644
--- a/include/mruby/compile.h
+++ b/include/mruby/compile.h
@@ -158,8 +158,8 @@ struct mrb_parser_state {
   struct mrb_parser_message warn_buffer[10];
 
   mrb_sym* filename_table;
-  size_t filename_table_length;
-  int current_filename_index;
+  uint16_t filename_table_length;
+  uint16_t current_filename_index;
 
   struct mrb_jmpbuf* jmp;
 };
diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index 5e6cda236..1c06be839 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -5900,7 +5900,11 @@ mrb_parser_set_filename(struct mrb_parser_state *p, const char *f)
     }
   }
 
-  p->current_filename_index = (int)p->filename_table_length++;
+  if (p->filename_table_length == UINT16_MAX) {
+    yyerror(p, "too many files to compile");
+    return;
+  }
+  p->current_filename_index = p->filename_table_length++;
 
   new_table = (mrb_sym*)parser_palloc(p, sizeof(mrb_sym) * p->filename_table_length);
   if (p->filename_table) {
@@ -5912,7 +5916,7 @@ mrb_parser_set_filename(struct mrb_parser_state *p, const char *f)
 
 MRB_API char const*
 mrb_parser_get_filename(struct mrb_parser_state* p, uint16_t idx) {
-  if (idx >= p->filename_table_length) { return NULL; }
+  if (idx >= p->filename_table_length) return NULL;
   else {
     return mrb_sym2name_len(p->mrb, p->filename_table[idx], NULL);
   }