[musl] Re: [PATCH] C23: update some legacy function pointers

[Michael Forney <mforney@mforney.org>]

Jens Gustedt <Jens.Gustedt@inria.fr> wrote:
> In C23, empty parameter lists loose their meaning as "function that
> may receive any number of parameters".
> 
> When compiling with -std=c2x, there were three left-overs in musl that
> still used that. Change them to use the correct prototype, since it is
> available at all these places, anyhow.

I think there's one more:

diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c
index 8294598b..e05f1623 100644
--- a/src/process/posix_spawn.c
+++ b/src/process/posix_spawn.c
@@ -149,7 +149,7 @@ static int child(void *args_vp)
 		? &attr->__mask : &args->oldmask, 0);
 
 	int (*exec)(const char *, char *const *, char *const *) =
-		attr->__fn ? (int (*)())attr->__fn : execve;
+		attr->__fn ? (int (*)(const char *, char *const *, char *const *))attr->__fn : execve;
 
 	exec(args->path, args->argv, args->envp);
 	ret = -errno;

Perhaps it's better to solve this by changing the type of __fn in
posix_spawnattr_t from void * to the appropriate function type, but
since this is in a public header, I'm not sure if it somehow breaks
something:

diff --git a/include/spawn.h b/include/spawn.h
index 8eb73e00..fec1280d 100644
--- a/include/spawn.h
+++ b/include/spawn.h
@@ -29,7 +29,7 @@ typedef struct {
 	pid_t __pgrp;
 	sigset_t __def, __mask;
 	int __prio, __pol;
-	void *__fn;
+	int (*__fn)(const char *, char *const *, char *const *);
 	char __pad[64-sizeof(void *)];
 } posix_spawnattr_t;
 
diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c
index 8294598b..2611fb94 100644
--- a/src/process/posix_spawn.c
+++ b/src/process/posix_spawn.c
@@ -149,7 +149,7 @@ static int child(void *args_vp)
 		? &attr->__mask : &args->oldmask, 0);
 
 	int (*exec)(const char *, char *const *, char *const *) =
-		attr->__fn ? (int (*)())attr->__fn : execve;
+		attr->__fn ? attr->__fn : execve;
 
 	exec(args->path, args->argv, args->envp);
 	ret = -errno;
diff --git a/src/process/posix_spawnp.c b/src/process/posix_spawnp.c
index aad6133b..28ef1aa4 100644
--- a/src/process/posix_spawnp.c
+++ b/src/process/posix_spawnp.c
@@ -8,6 +8,6 @@ int posix_spawnp(pid_t *restrict res, const char *restrict file,
 {
 	posix_spawnattr_t spawnp_attr = { 0 };
 	if (attr) spawnp_attr = *attr;
-	spawnp_attr.__fn = (void *)__execvpe;	
+	spawnp_attr.__fn = __execvpe;	
 	return posix_spawn(res, file, fa, &spawnp_attr, argv, envp);
 }