We were using -1 instead of the real size because the functions check
what is bigger, size in bytes or the size of the iov.  Recent gcc's
barf at this.

Signed-off-by: Juan Quintela <quintela@redhat.com>

--

Remove comments about this feature.
Fix missing -1.
---
 include/qemu/iov.h |  6 ------
 tests/test-iov.c   | 10 +++++-----
 2 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/include/qemu/iov.h b/include/qemu/iov.h
index bd9fd55b0a..72d4c559b4 100644
--- a/include/qemu/iov.h
+++ b/include/qemu/iov.h
@@ -31,11 +31,6 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt);
  * Number of bytes actually copied will be returned, which is
  *  min(bytes, iov_size(iov)-offset)
  * `Offset' must point to the inside of iovec.
- * It is okay to use very large value for `bytes' since we're
- * limited by the size of the iovec anyway, provided that the
- * buffer pointed to by buf has enough space.  One possible
- * such "large" value is -1 (sinice size_t is unsigned),
- * so specifying `-1' as `bytes' means 'up to the end of iovec'.
  */
 size_t iov_from_buf_full(const struct iovec *iov, unsigned int iov_cnt,
                          size_t offset, const void *buf, size_t bytes);
@@ -76,7 +71,6 @@ iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
  * up to the end of it, will be filled with the specified value.
  * Function return actual number of bytes processed, which is
  * min(size, iov_size(iov) - offset).
- * Again, it is okay to use large value for `bytes' to mean "up to the end".
  */
 size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt,
                   size_t offset, int fillc, size_t bytes);
diff --git a/tests/test-iov.c b/tests/test-iov.c
index a22d71fd2c..f40f8f5260 100644
--- a/tests/test-iov.c
+++ b/tests/test-iov.c
@@ -81,17 +81,17 @@ static void test_to_from_buf_1(void)
           * skip whole vector and process exactly 0 bytes */
 
          /* first set bytes [i..sz) to some "random" value */
-         n = iov_memset(iov, niov, 0, 0xff, -1);
+         n = iov_memset(iov, niov, 0, 0xff, sz);
          g_assert(n == sz);
 
          /* next copy bytes [i..sz) from ibuf to iovec */
-         n = iov_from_buf(iov, niov, i, ibuf + i, -1);
+         n = iov_from_buf(iov, niov, i, ibuf + i, sz - i);
          g_assert(n == sz - i);
 
          /* clear part of obuf */
          memset(obuf + i, 0, sz - i);
          /* and set this part of obuf to values from iovec */
-         n = iov_to_buf(iov, niov, i, obuf + i, -1);
+         n = iov_to_buf(iov, niov, i, obuf + i, sz - i);
          g_assert(n == sz - i);
 
          /* now compare resulting buffers */
@@ -109,7 +109,7 @@ static void test_to_from_buf_1(void)
               * with j in [i..sz]. */
 
              /* clear iovec */
-             n = iov_memset(iov, niov, 0, 0xff, -1);
+             n = iov_memset(iov, niov, 0, 0xff, sz);
              g_assert(n == sz);
 
              /* copy bytes [i..j) from ibuf to iovec */
@@ -226,7 +226,7 @@ static void test_io(void)
        for (i = 0; i <= sz; ++i) {
            for (j = i; j <= sz; ++j) {
                k = i;
-               iov_memset(iov, niov, 0, 0xff, -1);
+               iov_memset(iov, niov, 0, 0xff, sz);
                do {
                    s = g_test_rand_int_range(0, j - k + 1);
                    r = iov_recv(sv[0], iov, niov, k, s);
-- 
2.13.5

On 08/30/2017 07:33 AM, Juan Quintela wrote:
> We were using -1 instead of the real size because the functions check
> what is bigger, size in bytes or the size of the iov.  Recent gcc's
> barf at this.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> --
> 
> Remove comments about this feature.
> Fix missing -1.
> ---
>  include/qemu/iov.h |  6 ------
>  tests/test-iov.c   | 10 +++++-----
>  2 files changed, 5 insertions(+), 11 deletions(-)
> 
> diff --git a/include/qemu/iov.h b/include/qemu/iov.h
> index bd9fd55b0a..72d4c559b4 100644
> --- a/include/qemu/iov.h
> +++ b/include/qemu/iov.h
> @@ -31,11 +31,6 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt);
>   * Number of bytes actually copied will be returned, which is
>   *  min(bytes, iov_size(iov)-offset)
>   * `Offset' must point to the inside of iovec.
> - * It is okay to use very large value for `bytes' since we're
> - * limited by the size of the iovec anyway, provided that the
> - * buffer pointed to by buf has enough space.  One possible
> - * such "large" value is -1 (sinice size_t is unsigned),
> - * so specifying `-1' as `bytes' means 'up to the end of iovec'.
>   */
>  size_t iov_from_buf_full(const struct iovec *iov, unsigned int iov_cnt,
>                           size_t offset, const void *buf, size_t bytes);
> @@ -76,7 +71,6 @@ iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
>   * up to the end of it, will be filled with the specified value.
>   * Function return actual number of bytes processed, which is
>   * min(size, iov_size(iov) - offset).
> - * Again, it is okay to use large value for `bytes' to mean "up to the end".
>   */
>  size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt,
>                    size_t offset, int fillc, size_t bytes);
> diff --git a/tests/test-iov.c b/tests/test-iov.c
> index a22d71fd2c..f40f8f5260 100644
> --- a/tests/test-iov.c
> +++ b/tests/test-iov.c
> @@ -81,17 +81,17 @@ static void test_to_from_buf_1(void)
>            * skip whole vector and process exactly 0 bytes */
>  
>           /* first set bytes [i..sz) to some "random" value */
> -         n = iov_memset(iov, niov, 0, 0xff, -1);
> +         n = iov_memset(iov, niov, 0, 0xff, sz);
>           g_assert(n == sz);
>  
>           /* next copy bytes [i..sz) from ibuf to iovec */
> -         n = iov_from_buf(iov, niov, i, ibuf + i, -1);
> +         n = iov_from_buf(iov, niov, i, ibuf + i, sz - i);
>           g_assert(n == sz - i);
>  
>           /* clear part of obuf */
>           memset(obuf + i, 0, sz - i);
>           /* and set this part of obuf to values from iovec */
> -         n = iov_to_buf(iov, niov, i, obuf + i, -1);
> +         n = iov_to_buf(iov, niov, i, obuf + i, sz - i);
>           g_assert(n == sz - i);
>  
>           /* now compare resulting buffers */
> @@ -109,7 +109,7 @@ static void test_to_from_buf_1(void)
>                * with j in [i..sz]. */
>  
>               /* clear iovec */
> -             n = iov_memset(iov, niov, 0, 0xff, -1);
> +             n = iov_memset(iov, niov, 0, 0xff, sz);
>               g_assert(n == sz);
>  
>               /* copy bytes [i..j) from ibuf to iovec */
> @@ -226,7 +226,7 @@ static void test_io(void)
>         for (i = 0; i <= sz; ++i) {
>             for (j = i; j <= sz; ++j) {
>                 k = i;
> -               iov_memset(iov, niov, 0, 0xff, -1);
> +               iov_memset(iov, niov, 0, 0xff, sz);
>                 do {
>                     s = g_test_rand_int_range(0, j - k + 1);
>                     r = iov_recv(sv[0], iov, niov, k, s);
> 

Tested-by: Cleber Rosa <crosa@redhat.com>

On 08/30/2017 06:33 AM, Juan Quintela wrote:
> We were using -1 instead of the real size because the functions check
> what is bigger, size in bytes or the size of the iov.  Recent gcc's
> barf at this.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> --
> 
> Remove comments about this feature.
> Fix missing -1.
> ---
>  include/qemu/iov.h |  6 ------
>  tests/test-iov.c   | 10 +++++-----
>  2 files changed, 5 insertions(+), 11 deletions(-)
> 
> diff --git a/include/qemu/iov.h b/include/qemu/iov.h
> index bd9fd55b0a..72d4c559b4 100644
> --- a/include/qemu/iov.h
> +++ b/include/qemu/iov.h
> @@ -31,11 +31,6 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt);
>   * Number of bytes actually copied will be returned, which is
>   *  min(bytes, iov_size(iov)-offset)
>   * `Offset' must point to the inside of iovec.
> - * It is okay to use very large value for `bytes' since we're
> - * limited by the size of the iovec anyway, provided that the
> - * buffer pointed to by buf has enough space.

Is this part of the comment still okay?

>  One possible
> - * such "large" value is -1 (sinice size_t is unsigned),

Nice that we're losing the typo in the process :)

> - * so specifying `-1' as `bytes' means 'up to the end of iovec'.

I agree with dropping this though.  As mentioned elsewhere, we had
crossed mails between v1 reviews and v2 submission, so we'll probably
need a v3 anyways.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org