syscall overhaul part two - unify public and internal syscall interface

with this patch, the syscallN() functions are no longer needed; a
variadic syscall() macro allows syscalls with anywhere from 0 to 6
arguments to be made with a single macro name. also, manually casting
each non-integer argument with (long) is no longer necessary; the
casts are hidden in the macros.

some source files which depended on being able to define the old macro
SYSCALL_RETURNS_ERRNO have been modified to directly use __syscall()
instead of syscall(). references to SYSCALL_SIGSET_SIZE and SYSCALL_LL
have also been changed.

x86_64 has not been tested, and may need a follow-up commit to fix any
minor bugs/oversights.

1 files changed, 17 insertions, 1 deletions

diff --git a/include/sys/syscall.h b/include/sys/syscall.h
index a8fec678..c86135a3 100644
--- a/include/sys/syscall.h
+++ b/include/sys/syscall.h
@@ -4,11 +4,27 @@
 extern "C" {
 #endif
 
+long __syscall_ret(long);
+long __syscall(long, ...);
+long syscall(long, ...);
 
 #include <bits/syscall.h>
 
-long syscall(long, ...);
+#define __syscall1(n,a) __syscall1(n,(long)(a))
+#define __syscall2(n,a,b) __syscall2(n,(long)(a),(long)(b))
+#define __syscall3(n,a,b,c) __syscall3(n,(long)(a),(long)(b),(long)(c))
+#define __syscall4(n,a,b,c,d) __syscall4(n,(long)(a),(long)(b),(long)(c),(long)(d))
+#define __syscall5(n,a,b,c,d,e) __syscall5(n,(long)(a),(long)(b),(long)(c),(long)(d),(long)(e))
+#define __syscall6(n,a,b,c,d,e,f) __syscall6(n,(long)(a),(long)(b),(long)(c),(long)(d),(long)(e),(long)(f))
+
+#define __SYSCALL_NARGS_X(a,b,c,d,e,f,g,n,...) n
+#define __SYSCALL_NARGS(...) __SYSCALL_NARGS_X(__VA_ARGS__,6,5,4,3,2,1,0)
+#define __SYSCALL_CONCAT_X(a,b) a##b
+#define __SYSCALL_CONCAT(a,b) __SYSCALL_CONCAT_X(a,b)
+#define __SYSCALL_DISP(b,...) __SYSCALL_CONCAT(b,__SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
 
+#define __syscall(...) __SYSCALL_DISP(__syscall,__VA_ARGS__)
+#define syscall(...) __syscall_ret(__syscall(__VA_ARGS__))
 
 #ifdef __cplusplus
 }