From 3d4c5c21baa7d5fcb654c09e4e5dac4770ad570e Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Thu, 2 Oct 2014 15:26:58 +0100 Subject: [PATCH] Provide various wrappers for memcpy (COPY_OBJ, BUF_...) These wrappers avoid specifying the size separately or twice, and COPY_OBJ can check for type safety. No call sites yet. Signed-off-by: Ian Jackson --- secnet.h | 13 +++++++++++++ util.h | 25 +++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/secnet.h b/secnet.h index f0ab80b..5eeb213 100644 --- a/secnet.h +++ b/secnet.h @@ -551,4 +551,17 @@ extern void log_from_fd(int fd, cstring_t prefix, struct log_if *log); #define FILLZERO(obj) (memset(&(obj),0,sizeof((obj)))) +/* + * void COPY_OBJ( OBJECT& dst, const OBJECT& src); + * void COPY_ARRAY(OBJECT *dst, const OBJECT *src, INTEGER count); + * // Typesafe: we check that the type OBJECT is the same in both cases. + * // It is OK to use COPY_OBJ on an array object, proviced it's + * // _actually_ the whole array object and not decayed into a + * // pointer (e.g. a formal parameter). + */ +#define COPY_OBJ(dst,src) \ + (&(dst)==&(src), memcpy(&(dst),&(src),sizeof((dst)))) +#define COPY_ARRAY(dst,src,count) \ + (&(dst)[0]==&(src)[0], memcpy((dst),(src),sizeof((dst)[0])*(count))) + #endif /* secnet_h */ diff --git a/util.h b/util.h index 5866e57..725f233 100644 --- a/util.h +++ b/util.h @@ -29,6 +29,31 @@ extern void *buf_prepend(struct buffer_if *buf, int32_t amount); extern void *buf_unappend(struct buffer_if *buf, int32_t amount); extern void *buf_unprepend(struct buffer_if *buf, int32_t amount); +/* + * void BUF_ADD_BYTES(append, struct buffer_if*, const void*, int32_t size); + * void BUF_ADD_BYTES(prepend, struct buffer_if*, const void*, int32_t size); + * void BUF_GET_BYTES(unappend, struct buffer_if*, void*, int32_t size); + * void BUF_GET_BYTES(unprepend, struct buffer_if*, void*, int32_t size); + * // all of these evaluate size twice + * + * void BUF_ADD_OBJ(append, struct_buffer_if*, const OBJECT& something); + * void BUF_ADD_OBJ(prepend, struct_buffer_if*, const OBJECT& something); + * void BUF_GET_OBJ(unappend, struct_buffer_if*, OBJECT& something); + * void BUF_GET_OBJ(unprepend, struct_buffer_if*, OBJECT& something); + */ +#define BUF_ADD_BYTES(appendprepend, bufp, datap, size) \ + (buf_un##appendprepend /* ensures we have correct direction */, \ + memcpy(buf_##appendprepend((bufp),(size)),(datap),(size))) +#define BUF_ADD_OBJ(appendprepend, bufp, obj) \ + BUF_ADD_BYTES(appendprepend,(bufp),&(obj),sizeof((obj))) +#define BUF_GET_BYTES(unappendunprepend, bufp, datap, size) \ + (BUF_GET__DOESNOTEXIST__buf_un##unappendunprepend, \ + memcpy((datap),buf_##unappendunprepend((bufp),(size)),(size))) +#define BUF_GET_OBJ(unappendunprepend, bufp, obj) \ + BUF_ADD_BYTES(unappendunprepend,&(obj),(bufp),sizeof((obj))) +#define BUF_GET__DOESNOTEXIST__buf_ununappend 0 +#define BUF_GET__DOESNOTEXIST__buf_ununprepend 0 + static inline int32_t buf_remaining_space(const struct buffer_if *buf) { return (buf->base + buf->alloclen) - (buf->start + buf->size); -- 2.30.2