dynarray: Implement begin/end functions in the spirit of C++

  2017-06-13  Florian Weimer  <fweimer@redhat.com>

	* malloc/dynarray-skeleton.c: List begin/end/at as defined
	functions.  The at function was missing by accident.
	(DYNARRAY_PREFIX##begin, DYNARRAY_PREFIX##end): New functions.
	* malloc/tst-dynarray-shared.h (CHECK_EMPTY): Add tests for
	begin/end.
	* malloc/tst-dynarray.c (test_int): Test dynarray_int_begin,
	dynarray_int_end.
	(test_str): Test dynarray_str_begin, dynarray_str_end.
  

On 13/06/2017 12:21, Florian Weimer wrote:
> 2017-06-13  Florian Weimer  <fweimer@redhat.com>
> 
> 	* malloc/dynarray-skeleton.c: List begin/end/at as defined
> 	functions.  The at function was missing by accident.
> 	(DYNARRAY_PREFIX##begin, DYNARRAY_PREFIX##end): New functions.
> 	* malloc/tst-dynarray-shared.h (CHECK_EMPTY): Add tests for
> 	begin/end.
> 	* malloc/tst-dynarray.c (test_int): Test dynarray_int_begin,
> 	dynarray_int_end.
> 	(test_str): Test dynarray_str_begin, dynarray_str_end.

LGTM with just a remark below.

> 
> diff --git a/malloc/dynarray-skeleton.c b/malloc/dynarray-skeleton.c
> index 7a10e08..b0ee818 100644
> --- a/malloc/dynarray-skeleton.c
> +++ b/malloc/dynarray-skeleton.c
> @@ -65,6 +65,10 @@
>       bool DYNARRAY_PREFIX##has_failed (const struct DYNARRAY_STRUCT *);
>       void DYNARRAY_PREFIX##mark_failed (struct DYNARRAY_STRUCT *);
>       size_t DYNARRAY_PREFIX##size (const struct DYNARRAY_STRUCT *);
> +     DYNARRAY_ELEMENT *DYNARRAY_PREFIX##at
> +       (const struct DYNARRAY_STRUCT *, size_t);

I think there is already a non const DYNARRAY_PREFIX##at defined.


> +     DYNARRAY_ELEMENT *DYNARRAY_PREFIX##begin (const struct DYNARRAY_STRUCT *);
> +     DYNARRAY_ELEMENT *DYNARRAY_PREFIX##end (const struct DYNARRAY_STRUCT *);
>       DYNARRAY_ELEMENT *DYNARRAY_PREFIX##at (struct DYNARRAY_STRUCT *, size_t);
>       void DYNARRAY_PREFIX##add (struct DYNARRAY_STRUCT *, DYNARRAY_ELEMENT);
>       DYNARRAY_ELEMENT *DYNARRAY_PREFIX##emplace (struct DYNARRAY_STRUCT *);
> @@ -248,6 +252,26 @@ DYNARRAY_NAME (at) (struct DYNARRAY_STRUCT *list, size_t index)
>    return list->dynarray_header.array + index;
>  }
>  
> +/* Return a pointer to the first array element, if any.  For a
> +   zero-length array, the pointer can be NULL even though the dynamic
> +   array has not entered the failure state.  */
> +__attribute__ ((nonnull (1)))
> +static inline DYNARRAY_ELEMENT *
> +DYNARRAY_NAME (begin) (struct DYNARRAY_STRUCT *list)
> +{
> +  return list->dynarray_header.array;
> +}
> +
> +/* Return a pointer one element past the last array element.  For a
> +   zero-length array, the pointer can be NULL even though the dynamic
> +   array has not entered the failure state.  */
> +__attribute__ ((nonnull (1)))
> +static inline DYNARRAY_ELEMENT *
> +DYNARRAY_NAME (end) (struct DYNARRAY_STRUCT *list)
> +{
> +  return list->dynarray_header.array + list->dynarray_header.used;
> +}
> +
>  /* Internal function.  Slow path for the add function below.  */
>  static void
>  DYNARRAY_NAME (add__) (struct DYNARRAY_STRUCT *list, DYNARRAY_ELEMENT item)
> diff --git a/malloc/tst-dynarray-shared.h b/malloc/tst-dynarray-shared.h
> index faba66f..1de9c04 100644
> --- a/malloc/tst-dynarray-shared.h
> +++ b/malloc/tst-dynarray-shared.h
> @@ -73,5 +73,8 @@ struct str_array
>      TEST_VERIFY_EXIT (dynarray_##type##_emplace (dyn) == NULL);      \
>      dynarray_##type##_free (dyn);                                    \
>      CHECK_INIT_STATE (type, (dyn));                                  \
> +    /* These functions should not assert.  */                        \
> +    dynarray_##type##_begin (dyn);                                   \
> +    dynarray_##type##_end (dyn);                                     \
>      (void) 0;                                                        \
>    })
> diff --git a/malloc/tst-dynarray.c b/malloc/tst-dynarray.c
> index 7aee85a..2206d75 100644
> --- a/malloc/tst-dynarray.c
> +++ b/malloc/tst-dynarray.c
> @@ -111,6 +111,13 @@ test_int (void)
>                  }
>                TEST_VERIFY_EXIT (dynarray_int_size (&dyn) == count);
>                TEST_VERIFY_EXIT (count <= dyn.dynarray_header.allocated);
> +              if (count > 0)
> +                {
> +                  TEST_VERIFY (dynarray_int_begin (&dyn)
> +                               == dynarray_int_at (&dyn, 0));
> +                  TEST_VERIFY (dynarray_int_end (&dyn)
> +                               == dynarray_int_at (&dyn, count - 1) + 1);
> +                }
>                unsigned final_count;
>                bool heap_array = dyn.dynarray_header.array != dyn.scratch;
>                if (do_remove_last)
> @@ -123,6 +130,13 @@ test_int (void)
>                  }
>                else
>                  final_count = count;
> +              if (final_count > 0)
> +                {
> +                  TEST_VERIFY (dynarray_int_begin (&dyn)
> +                               == dynarray_int_at (&dyn, 0));
> +                  TEST_VERIFY (dynarray_int_end (&dyn)
> +                               == dynarray_int_at (&dyn, final_count - 1) + 1);
> +                }
>                if (do_clear)
>                  {
>                    dynarray_int_clear (&dyn);
> @@ -225,6 +239,13 @@ test_str (void)
>                  }
>                TEST_VERIFY_EXIT (dynarray_str_size (&dyn) == count);
>                TEST_VERIFY_EXIT (count <= dyn.dynarray_header.allocated);
> +              if (count > 0)
> +                {
> +                  TEST_VERIFY (dynarray_str_begin (&dyn)
> +                               == dynarray_str_at (&dyn, 0));
> +                  TEST_VERIFY (dynarray_str_end (&dyn)
> +                               == dynarray_str_at (&dyn, count - 1) + 1);
> +                }
>                unsigned final_count;
>                bool heap_array = dyn.dynarray_header.array != dyn.scratch;
>                if (do_remove_last)
> @@ -237,6 +258,13 @@ test_str (void)
>                  }
>                else
>                  final_count = count;
> +              if (final_count > 0)
> +                {
> +                  TEST_VERIFY (dynarray_str_begin (&dyn)
> +                               == dynarray_str_at (&dyn, 0));
> +                  TEST_VERIFY (dynarray_str_end (&dyn)
> +                               == dynarray_str_at (&dyn, final_count - 1) + 1);
> +                }
>                if (do_clear)
>                  {
>                    dynarray_str_clear (&dyn);
>
  

On 06/13/2017 08:54 PM, Adhemerval Zanella wrote:
> I think there is already a non const DYNARRAY_PREFIX##at defined.

Right, I was confused.  I'm committing this without this comment change
and its mention in the ChangeLog.

Thanks,
Florian