udebug: add functions for manipulating entry length

[project/libubox.git] / utils.h

diff --git a/utils.h b/utils.h
index aa480e254a8ee9f405a93c6ae2124bfcce6306ab..dacac6e41092e2b395f3867fa6dd91812a40acf8 100644 (file)
--- a/utils.h
+++ b/utils.h
@@ -19,6 +19,7 @@
 #ifndef __LIBUBOX_UTILS_H
 #define __LIBUBOX_UTILS_H
 
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #include <stdint.h>
@@ -117,21 +118,54 @@ int clock_gettime(int type, struct timespec *tv);
        (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) |     \
        (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56)))
 
+/*
+ * This returns a constant expression while determining if an argument is
+ * a constant expression, most importantly without evaluating the argument.
+ */
+#define __is_constant(x)                                               \
+       (sizeof(int) == sizeof(*(1 ? ((void*)((long)(x) * 0l)) : (int*)1)))
 
-static inline uint16_t __u_bswap16(uint16_t val)
-{
-       return ((val >> 8) & 0xffu) | ((val & 0xffu) << 8);
-}
+#define __eval_once(func, x)                                           \
+       ({ __typeof__(x) __x = x; func(__x); })
+
+#ifdef __cplusplus
+/*
+ * g++ does not support __builtin_choose_expr, so always use __eval_once.
+ * Unfortunately this means that the byte order functions can't be used
+ * as a constant expression anymore
+ */
+#define __eval_safe(func, x) __eval_once(func, x)
+#else
+#define __eval_safe(func, x)                                           \
+       __builtin_choose_expr(__is_constant(x),                         \
+                             func(x), __eval_once(func, x))
+#endif
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 
-#define cpu_to_be64(x) __constant_swap64(x)
-#define cpu_to_be32(x) __constant_swap32(x)
-#define cpu_to_be16(x) __constant_swap16(x)
+#define const_cpu_to_be64(x) __constant_swap64(x)
+#define const_cpu_to_be32(x) __constant_swap32(x)
+#define const_cpu_to_be16(x) __constant_swap16(x)
+
+#define const_be64_to_cpu(x) __constant_swap64(x)
+#define const_be32_to_cpu(x) __constant_swap32(x)
+#define const_be16_to_cpu(x) __constant_swap16(x)
+
+#define const_cpu_to_le64(x) (x)
+#define const_cpu_to_le32(x) (x)
+#define const_cpu_to_le16(x) (x)
 
-#define be64_to_cpu(x) __constant_swap64(x)
-#define be32_to_cpu(x) __constant_swap32(x)
-#define be16_to_cpu(x) __constant_swap16(x)
+#define const_le64_to_cpu(x) (x)
+#define const_le32_to_cpu(x) (x)
+#define const_le16_to_cpu(x) (x)
+
+#define cpu_to_be64(x) __eval_safe(__constant_swap64, x)
+#define cpu_to_be32(x) __eval_safe(__constant_swap32, x)
+#define cpu_to_be16(x) __eval_safe(__constant_swap16, x)
+
+#define be64_to_cpu(x) __eval_safe(__constant_swap64, x)
+#define be32_to_cpu(x) __eval_safe(__constant_swap32, x)
+#define be16_to_cpu(x) __eval_safe(__constant_swap16, x)
 
 #define cpu_to_le64(x) (x)
 #define cpu_to_le32(x) (x)
@@ -143,13 +177,29 @@ static inline uint16_t __u_bswap16(uint16_t val)
 
 #else /* __BYTE_ORDER == __LITTLE_ENDIAN */
 
-#define cpu_to_le64(x) __constant_swap64(x)
-#define cpu_to_le32(x) __constant_swap32(x)
-#define cpu_to_le16(x) __constant_swap16(x)
+#define const_cpu_to_le64(x) __constant_swap64(x)
+#define const_cpu_to_le32(x) __constant_swap32(x)
+#define const_cpu_to_le16(x) __constant_swap16(x)
+
+#define const_le64_to_cpu(x) __constant_swap64(x)
+#define const_le32_to_cpu(x) __constant_swap32(x)
+#define const_le16_to_cpu(x) __constant_swap16(x)
+
+#define const_cpu_to_be64(x) (x)
+#define const_cpu_to_be32(x) (x)
+#define const_cpu_to_be16(x) (x)
+
+#define const_be64_to_cpu(x) (x)
+#define const_be32_to_cpu(x) (x)
+#define const_be16_to_cpu(x) (x)
 
-#define le64_to_cpu(x) __constant_swap64(x)
-#define le32_to_cpu(x) __constant_swap32(x)
-#define le16_to_cpu(x) __constant_swap16(x)
+#define cpu_to_le64(x) __eval_safe(__constant_swap64, x)
+#define cpu_to_le32(x) __eval_safe(__constant_swap32, x)
+#define cpu_to_le16(x) __eval_safe(__constant_swap16, x)
+
+#define le64_to_cpu(x) __eval_safe(__constant_swap64, x)
+#define le32_to_cpu(x) __eval_safe(__constant_swap32, x)
+#define le16_to_cpu(x) __eval_safe(__constant_swap16, x)
 
 #define cpu_to_be64(x) (x)
 #define cpu_to_be32(x) (x)
@@ -177,6 +227,18 @@ static inline uint16_t __u_bswap16(uint16_t val)
 #define __hidden __attribute__((visibility("hidden")))
 #endif
 
+#ifndef __has_attribute
+# define __has_attribute(x) 0
+#endif
+
+#ifndef fallthrough
+# if __has_attribute(__fallthrough__)
+#  define fallthrough __attribute__((__fallthrough__))
+# else
+#  define fallthrough do {} while (0)  /* fallthrough */
+# endif
+#endif
+
 int b64_encode(const void *src, size_t src_len,
               void *dest, size_t dest_len);
 
@@ -203,5 +265,6 @@ static inline unsigned long cbuf_size(int order)
 
 void *cbuf_alloc(unsigned int order);
 void cbuf_free(void *ptr, unsigned int order);
+int mkdir_p(char *dir, mode_t mask);
 
 #endif