YYERROR; \
} while (0)
-#define ALLOC(ptr, size) do { \
- (ptr) = malloc(size); \
- if (!(ptr)) { \
- cdecl__errmsg(CDECL__ENOMEM); \
+/*
+ * Allocate a parse tree node via cdecl__alloc_item.
+ *
+ * - m1 specifies the item's union member to assign to ptr, which selects the
+ * type of node to allocate.
+ *
+ * - m2 specifies the "next" or "child" member, which is initialized to a null
+ * pointer. The cdecl__alloc_item function sets the declarator.child member
+ * to null; we explicitly copy this null pointer to the returned union member
+ * to avoid type punning. It is hoped that compilers will notice that these
+ * pointers are at the same offset therefore the assignment can be elided.
+ *
+ * The resulting pointer can be passed directly to free, as the union is the
+ * first member of the parse_item structure.
+ *
+ * Use the wrapper macros below instead of this one.
+ */
+#define ALLOC_ITEM(ptr, m1, m2) do { \
+ struct parse_item *item; \
+ if (!(item = cdecl__alloc_item(0))) \
YYERROR; \
- } \
+ item->u.m1.m2 = (void *)item->u.declarator.child; \
+ (ptr) = &item->u.m1; \
} while (0)
+/* Wrappers for ALLOC_ITEM to allocate various kinds of parser structures. */
+#define ALLOC_ITEM_DECLARATOR(ptr) ALLOC_ITEM(ptr, declarator, child)
+#define ALLOC_ITEM_DECLSPEC(ptr) ALLOC_ITEM(ptr, declspec, next)
+#define ALLOC_ITEM_DECL(ptr) ALLOC_ITEM(ptr, decl, next)
+
#define ALLOC_FUNCTION(ptr, parameters_, variadic_) do { \
- ALLOC(ptr, sizeof (struct cdecl_declarator)); \
+ ALLOC_ITEM_DECLARATOR(ptr); \
(ptr)->type = CDECL_DECL_FUNCTION; \
(ptr)->u.function.parameters = parameters_; \
(ptr)->u.function.variadic = variadic_; \
} while (0)
#define ALLOC_ARRAY(ptr, length_) do { \
- ALLOC(ptr, sizeof (struct cdecl_declarator)); \
+ ALLOC_ITEM_DECLARATOR(ptr); \
(ptr)->type = CDECL_DECL_ARRAY; \
(ptr)->u.array.vla = NULL; \
(ptr)->u.array.length = length_; \
} while (0)
#define ALLOC_POINTER(ptr, qualifiers_, child_) do { \
- ALLOC(ptr, sizeof (struct cdecl_declarator)); \
+ ALLOC_ITEM_DECLARATOR(ptr); \
(ptr)->child = child_; \
(ptr)->type = CDECL_DECL_POINTER; \
(ptr)->u.pointer.qualifiers = qualifiers_; \
} while (0)
#define ALLOC_DECLSPEC(ptr, type_) do { \
- ALLOC(ptr, sizeof (struct cdecl_declspec)); \
+ ALLOC_ITEM_DECLSPEC(ptr); \
(ptr)->type = type_; \
(ptr)->ident = NULL; \
} while (0)
#define ALLOC_DECL(ptr, specifiers_, declarators_) do { \
- ALLOC(ptr, sizeof (struct cdecl)); \
+ ALLOC_ITEM_DECL(ptr); \
(ptr)->specifiers = specifiers_; \
(ptr)->declarators = declarators_; \
- (ptr)->next = NULL; \
} while (0)
/*