add class declaration to the parser

src/parser/parser.l

@@ -131,6 +131,8 @@ asm                 return ASM;
 __asm__             return ASM;
 __extension__       return EXTENSION;
 
+class               return CLASS;
+
 L?'[^\\]'           return CHAR_CONST;
 L?'\\.'             return CHAR_CONST;
 L?'\\x[0-9A-Fa-f]{2}'   return CHAR_CONST;

src/parser/parser.yc

@@ -117,6 +117,8 @@ int yylex(YYSTYPE *, YYLTYPE *);
 %token ASM;
 %token EXTENSION;
 
+%token CLASS;
+
 %start translation_unit
 
 %%
@@ -591,6 +593,7 @@ type_specifier
     | UNSIGNED { $$ = $1; }
     | struct_or_union_specifier { $$ = $1; }
     | enum_specifier { $$ = $1; }
+    | class_specifier { $$ = $1; }
     | TYPE_NAME { $$ = $1; }
     ;
 
@@ -743,6 +746,26 @@ enumerator
     }
     ;
 
+class_specifier
+    : CLASS IDENTIFIER LCURLY RCURLY {
+        $$ = new Node(NODE_TYPE_LIST);
+    }
+    | CLASS IDENTIFIER LCURLY external_declaration_list RCURLY {
+        $$ = new Node(NODE_TYPE_LIST);
+    }
+    ;
+
+external_declaration_list
+    : external_declaration {
+        $$ = new Node(NODE_TYPE_LIST);
+        $$->list->push_back($1);
+    }
+    | external_declaration_list external_declaration {
+        $$ = $1;
+        $$->list->push_back($2);
+    }
+    ;
+
 type_qualifier
     : CONST { $$ = $1; }
     | VOLATILE { $$ = $1; }