"Johannes Schindelin via GitGitGadget" <gitgitgadget@xxxxxxxxx>
writes:
> From: Johannes Schindelin <johannes.schindelin@xxxxxx>
>
> The kwset functionality makes use of the obstack code, which expects to
> be handed a function that can allocate large chunks of data. It expects
> that function to accept a `size` parameter of type `long`.
>
> This upsets GCC 8 on Windows, because `long` does not have the same
> bit size as `size_t` there.
>
> Now, the proper thing to do would be to switch to `size_t`. But this
> would make us deviate from the "upstream" code even further, making it
> hard to synchronize with newer versions, and also it would be quite
> involved because that `long` type is so invasive in that code.
>
> Let's punt, and instead provide a super small wrapper around
> `xmalloc()`.
Yay.
The above description makes it sound as if this patch is an ugly
workaround, but I think this is "the proper thing" to do, as long as
the use of obstack stuff in this context is meant to allocate less
than MAX_LONG bytes at a time, even if long is somtimes smaller than
size_t.
Thanks.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
> ---
> kwset.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/kwset.c b/kwset.c
> index 4fb6455aca..efc2ff41bc 100644
> --- a/kwset.c
> +++ b/kwset.c
> @@ -38,7 +38,13 @@
> #include "compat/obstack.h"
>
> #define NCHAR (UCHAR_MAX + 1)
> -#define obstack_chunk_alloc xmalloc
> +/* adapter for `xmalloc()`, which takes `size_t`, not `long` */
> +static void *obstack_chunk_alloc(long size)
> +{
> + if (size < 0)
> + BUG("Cannot allocate a negative amount: %ld", size);
> + return xmalloc(size);
> +}
> #define obstack_chunk_free free
>
> #define U(c) ((unsigned char) (c))
