Add builtin type _Bool and tweak lexer aliasing

The size of type _Bool is same as char type, which takes 1 byte.

Notice that currently lexer aliasing is unreliable due to the token
type determination algorithm does not correctly recognize T_identifier
and T_string at this moment.

Author: ChAoSUnItY

src/lexer.c

@@ -130,7 +130,8 @@ bool is_hex(char c)
 
 bool is_numeric(char buffer[])
 {
-    int hex = 0, size = strlen(buffer);
+    bool hex = false;
+    int size = strlen(buffer);
 
     if (size > 2)
         hex = buffer[0] == '0' && buffer[1] == 'x';
@@ -518,7 +519,8 @@ token_t lex_token_internal(bool aliasing)
         if (aliasing) {
             alias = find_alias(token_str);
             if (alias) {
-                token_t t = is_numeric(alias) ? T_numeric : T_string;
+                /* TODO: Need more reliable way to identify the token's type */
+                token_t t = is_numeric(alias) ? T_numeric : T_identifier;
                 strcpy(token_str, alias);
                 return t;
             }

src/parser.c

@@ -2875,6 +2875,14 @@ void parse_internal()
     type->base_type = TYPE_int;
     type->size = 4;
 
+    /* builtin type _Bool was introduced in C99 specification, it is more well-known
+     * as macro type bool, which is defined in <std_bool.h> (in shecc, it is defined 
+     * in 'lib/c.c').
+     */
+    type = add_named_type("_Bool");
+    type->base_type = TYPE_char;
+    type->size = 1;
+
     add_block(NULL, NULL, NULL); /* global block */
     elf_add_symbol("", 0, 0);    /* undef symbol */
 

tests/driver.sh

@@ -592,4 +592,13 @@ int main()
 }
 EOF
 
+# _Bool size should be equivalent to char, which is 1 byte
+try_output 0 "1" << EOF
+int main()
+{
+    printf("%d", sizeof(bool));
+    return 0;
+}
+EOF
+
 echo OK