bug#73835: Build failure with gcc 14 and musl on 32 bit

On Wed, 16 Oct 2024 09:56:22 +0200
Natanael Copa <[email protected]> wrote:

> Hi,
> 
> I get this error message when compiling guile 3.0.9 and 3.0.10 with gcc
> 14 / musl libc on 32 bit Alpine Linux:
> 
> filesys.c: In function 'scm_sendfile':
> filesys.c:1405:16: error: assignment to 'off_t *' {aka 'long long int *'} from incompatible pointer type 'scm_t_off *' {aka 'long int *'} [-Wincompatible-pointer-types]
>  1405 |     offset_ptr = SCM_UNBNDP (offset) ? NULL : &c_offset;
>       |                ^
> 
> It looks like an assumption that off_t is 32 bit, which is not true on musl libc.
> 
> -nc

This appears to solve it:

diff --git a/libguile/filesys.c b/libguile/filesys.c
index 70a6ef6..0500d45 100644
--- a/libguile/filesys.c
+++ b/libguile/filesys.c
@@ -1388,7 +1388,7 @@ SCM_DEFINE (scm_sendfile, "sendfile", 3, 1, 0,
 
   ssize_t result SCM_UNUSED;
   size_t c_count, total = 0;
-  scm_t_off c_offset;
+  off_t c_offset;
   int in_fd, out_fd;
 
   VALIDATE_FD_OR_PORT (out_fd, out, 1);