typeof cleanup

Author: yamt

lib/decode.h

@@ -2,6 +2,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "platform.h"
+
 int read_u8(const uint8_t **pp, const uint8_t *ep, uint8_t *resultp);
 int read_u32(const uint8_t **pp, const uint8_t *ep, uint32_t *resultp);
 int read_u64(const uint8_t **pp, const uint8_t *ep, uint64_t *resultp);
@@ -21,14 +23,21 @@ int read_vec_with_ctx(const uint8_t **pp, const uint8_t *ep, size_t elem_size,
                       void (*clear_elem)(void *elem), void *ctx,
                       uint32_t *countp, void **resultp);
 
+#if defined(toywasm_typeof)
 /* a version with non-standard checks */
 #define read_vec_with_ctx2(pp, ep, elem_size, read_elem, clear_elem, ctx,     \
                            countp, resultp)                                   \
         ({                                                                    \
                 int (*_r)(const uint8_t **, const uint8_t *, uint32_t,        \
-                          __typeof__(*resultp), void *) = read_elem;          \
-                void (*_c)(__typeof__(*resultp)) = clear_elem;                \
+                          toywasm_typeof(*resultp), void *) = read_elem;      \
+                void (*_c)(toywasm_typeof(*resultp)) = clear_elem;            \
                 assert(sizeof(**resultp) == elem_size);                       \
                 read_vec_with_ctx(pp, ep, elem_size, (void *)_r, (void *)_c,  \
                                   ctx, countp, (void **)resultp);             \
         })
+#else
+#define read_vec_with_ctx2(pp, ep, elem_size, read_elem, clear_elem, ctx,     \
+                           countp, resultp)                                   \
+        read_vec_with_ctx(pp, ep, elem_size, (void *)read_elem,               \
+                          (void *)clear_elem, ctx, countp, (void **)resultp)
+#endif

lib/list.h

@@ -31,10 +31,10 @@ void list_insert_tail(struct list_head *h, void *elem, struct list_entry *e);
 #define LIST_FOREACH(VAR, HEAD, NAME)                                         \
         for (VAR = (HEAD)->first; VAR != NULL; VAR = (VAR)->NAME.next)
 
-#if defined(__clang__)
+#if defined(toywasm_typeof)
 #define CHECK_TYPE(a, b)                                                      \
         do {                                                                  \
-                __attribute__((__unused__)) __typeof__(a) __dummy = b;        \
+                __attribute__((__unused__)) toywasm_typeof(a) __dummy = b;    \
         } while (0)
 #else
 #define CHECK_TYPE(a, b)

lib/platform.h

@@ -56,3 +56,16 @@
 #else
 #define ctassert(e)
 #endif
+
+/*
+ * https://gcc.gnu.org/onlinedocs/gcc/Typeof.html
+ * clang also has it.
+ *
+ * Note: we don't want to rely on typeof.
+ * any use of it in toywasm should have a fallback implementation.
+ */
+#if defined(__GNUC__)
+#define toywasm_typeof(a) __typeof__(a)
+#else
+#undef toywasm_typeof
+#endif