diff --git a/include/runtime.h b/include/runtime.h
index 94745fb..00f661c 100644
--- a/include/runtime.h
+++ b/include/runtime.h
@@ -5,7 +5,9 @@
 
 #include "parser.h"
 
-extern int show_warning;
+#include <stdbool.h>
+
+extern bool show_warning;
 extern int warning_cnt;
 extern char *user_input;
 extern CharPtrList *user_input_list;
@@ -37,6 +39,8 @@ extern FileName *filenames;
 extern char *input_file;
 extern char *output_file;
 extern Location *consumed_loc;
+extern int hierarchy_level;
+extern bool print_include_files;
 extern IncludePath *include_paths;
 extern FILE *fp;
 extern Macro *macros;
diff --git a/src/lexer/preprocess_include.c b/src/lexer/preprocess_include.c
index 2cd63b0..e459656 100644
--- a/src/lexer/preprocess_include.c
+++ b/src/lexer/preprocess_include.c
@@ -22,7 +22,14 @@ static void handle_include_directive(char *name, char *p, int is_system_header)
   free(raw_name);
 
   char *input_file_prev = input_file;
+  int prev_level = hierarchy_level;
+  hierarchy_level++;
   input_file = resolved_path;
+  if (print_include_files) {
+    for (int i = 0; i < hierarchy_level; i++)
+      fprintf(stderr, ".");
+    fprintf(stderr, " %s\n", resolved_path);
+  }
   FileName *filename = malloc(sizeof(FileName));
   filename->name = resolved_path;
   filename->next = filenames;
@@ -43,6 +50,7 @@ static void handle_include_directive(char *name, char *p, int is_system_header)
 
   user_input = user_input_prev;
   input_file = input_file_prev;
+  hierarchy_level = prev_level;
 }
 
 static void handle_include_next_directive(char *name, char *p) {
diff --git a/src/main.c b/src/main.c
index 711b9ac..8ab1e76 100644
--- a/src/main.c
+++ b/src/main.c
@@ -227,6 +227,8 @@ int main(int argc, char **argv) {
     } else if (!strncmp(argv[i], "-S", 2)) {
     } else if (!strncmp(argv[i], "-w", 2)) {
       show_warning = false;
+    } else if (!strncmp(argv[i], "-H", 2)) {
+      print_include_files = true;
     } else if (!strncmp(argv[i], "-o", 2) && i + 1 < argc) {
       if (output_file_specified) {
         error("multiple output files specified.");
@@ -255,6 +257,7 @@ int main(int argc, char **argv) {
       filename->name = input_file;
       filename->next = filenames;
       filenames = filename;
+      hierarchy_level = 0;
       if (strncmp(input_file + length - 2, ".c", 2)) {
         error("source file must have a .c extension.");
       }
diff --git a/src/parser/decl.c b/src/parser/decl.c
index b715eae..8de7e26 100644
--- a/src/parser/decl.c
+++ b/src/parser/decl.c
@@ -748,6 +748,10 @@ Node *typedef_stmt() {
   Token *tok;
   type = parse_declarator(type, &tok, "typedef");
   skip_gnu_asm_specifier("asm specifier");
+  if (!type) {
+    Location *loc = token ? token->loc : consumed_loc;
+    error_at(loc, "expected a type [in typedef]");
+  }
   if (!tok) {
     Location *loc = token ? token->loc : consumed_loc;
     error_at(loc, "expected an identifier [in typedef statement]");
diff --git a/src/parser/parse.c b/src/parser/parse.c
index f40451d..0a54cc4 100644
--- a/src/parser/parse.c
+++ b/src/parser/parse.c
@@ -78,8 +78,14 @@ int parse_sign() {
 
 // 数値の期待値取得（符号付き）
 int expect_signed_number() {
-  int sign = parse_sign();
-  return expect_number("expect signed number") * sign;
+  Token *tok = token;
+  Node *expr_node = assign();
+  int ok = true;
+  int value = eval_const_expr(expr_node, &ok);
+  if (!ok) {
+    error_at(tok->loc, "expected a compile time constant [in expect signed number statement]");
+  }
+  return value;
 }
 
 void error_duplicate_name(Token *tok, const char *type) {
diff --git a/src/types/type.c b/src/types/type.c
index e183d94..17cbe1e 100644
--- a/src/types/type.c
+++ b/src/types/type.c
@@ -132,23 +132,13 @@ Type *parse_base_type_internal(const int should_consume, const int should_record
     type->ty = TY_INT;
     type->object = enum_declaration(should_record);
   } else if (token->kind == TK_IDENT) {
-    // サポートしていないが、システムヘッダで現れる組込み型に対する最低限の対応
-    // 例: glibc の stdarg.h などで使用される '__builtin_va_list'
-    if (token->len == (int)strlen("__builtin_va_list") && strncmp(token->str, "__builtin_va_list", token->len) == 0) {
+    int bits = 0;
+    int is_unsigned = 0;
+    if (token_matches(token, "__builtin_va_list")) {
       // 内部表現としては void* 相当で十分（実際のレイアウトは不要）
       Type *void_ty = new_type(TY_VOID);
       type = new_type_ptr(void_ty);
       token = token->next;
-    } else if (token->len == (int)strlen("wchar_t") && strncmp(token->str, "wchar_t", token->len) == 0) {
-      // C では本来 typedef だが、ヘッダ互換性のためビルトイン扱い（LP64 では int 相当）
-      type->ty = TY_INT;
-      type->is_unsigned = false;
-      token = token->next;
-    } else if (token->len == (int)strlen("size_t") && strncmp(token->str, "size_t", token->len) == 0) {
-      // size_t をビルトイン型として扱う（LP64 では unsigned long）
-      type->ty = TY_LONG;
-      type->is_unsigned = true;
-      token = token->next;
     } else {
       TypeTag *type_tag = find_type_tag(token);
       if (type_tag) {
@@ -718,9 +708,9 @@ int is_type(Token *tok) {
   if (tok->kind == TK_IDENT) {
     // Recognize common typedef-like builtins even before their typedefs are seen
     // to match parse_base_type() behavior (e.g., size_t, wchar_t, __builtin_va_list).
-    if ((tok->len == (int)strlen("size_t") && strncmp(tok->str, "size_t", tok->len) == 0) ||
-        (tok->len == (int)strlen("wchar_t") && strncmp(tok->str, "wchar_t", tok->len) == 0) ||
-        (tok->len == (int)strlen("__builtin_va_list") && strncmp(tok->str, "__builtin_va_list", tok->len) == 0)) {
+    int bits = 0;
+    int is_unsigned = 0;
+    if (tok->len == (int)strlen("__builtin_va_list") && strncmp(tok->str, "__builtin_va_list", tok->len) == 0) {
       return true;
     }
 
diff --git a/src/utils/globals.c b/src/utils/globals.c
index 559aed7..9c87a69 100644
--- a/src/utils/globals.c
+++ b/src/utils/globals.c
@@ -2,9 +2,10 @@
 #include "parser.h"
 #include "source.h"
 
+#include <stdbool.h>
 #include <stdio.h>
 
-int show_warning = 1;
+bool show_warning = true;
 int warning_cnt = 0;
 char *user_input = 0;
 CharPtrList *user_input_list = 0;
@@ -18,28 +19,30 @@ int loop_id = -1;
 int variable_cnt = 0;
 int block_cnt = 0;
 int block_id = 0;
-Node *current_switch = 0;
-Function *functions = 0;
-Function *current_fn = 0;
-LVar *locals = 0;
-LVar *globals = 0;
-LVar *statics = 0;
-Object *structs = 0;
-Object *unions = 0;
-Object *enums = 0;
-Object *current_enum_scope = 0;
-TypeTag *type_tags = 0;
-String *strings = 0;
-Array *arrays = 0;
-StructLiteral *struct_literals = 0;
-FileName *filenames = 0;
-char *input_file = 0;
-char *output_file = 0;
-Location *consumed_loc = 0;
+Node *current_switch = NULL;
+Function *functions = NULL;
+Function *current_fn = NULL;
+LVar *locals = NULL;
+LVar *globals = NULL;
+LVar *statics = NULL;
+Object *structs = NULL;
+Object *unions = NULL;
+Object *enums = NULL;
+Object *current_enum_scope = NULL;
+TypeTag *type_tags = NULL;
+String *strings = NULL;
+Array *arrays = NULL;
+StructLiteral *struct_literals = NULL;
+FileName *filenames = NULL;
+char *input_file = NULL;
+char *output_file = NULL;
+Location *consumed_loc = NULL;
+int hierarchy_level = -1;
+bool print_include_files = false;
 
-IncludePath *include_paths = 0;
-FILE *fp = 0;
-Macro *macros = 0;
+IncludePath *include_paths = NULL;
+FILE *fp = NULL;
+Macro *macros = NULL;
 
 void init_global_variables() {
   // グローバル変数の初期化