[PATCH v5 2/5] tools/nolibc: fix up undeclared syscall macros with #ifdef and -ENOSYS

From: Zhangjin Wu
Date: Mon Jun 19 2023 - 08:27:06 EST


Compiling nolibc for rv32 got such errors:

nolibc/sysroot/riscv/include/sys.h: In function ‘sys_gettimeofday’:
nolibc/sysroot/riscv/include/sys.h:557:21: error: ‘__NR_gettimeofday’ undeclared (first use in this function); did you mean ‘sys_gettimeofday’?
557 | return my_syscall2(__NR_gettimeofday, tv, tz);
| ^~~~~~~~~~~~~~~~~
nolibc/sysroot/riscv/include/sys.h: In function ‘sys_lseek’:
nolibc/sysroot/riscv/include/sys.h:675:21: error: ‘__NR_lseek’ undeclared (first use in this function)
675 | return my_syscall3(__NR_lseek, fd, offset, whence);
| ^~~~~~~~~~
nolibc/sysroot/riscv/include/sys.h: In function ‘sys_wait4’:
nolibc/sysroot/riscv/include/sys.h:1341:21: error: ‘__NR_wait4’ undeclared (first use in this function)
1341 | return my_syscall4(__NR_wait4, pid, status, options, rusage);

If a syscall macro is not supported by a target platform, wrap it with
'#ifdef' and 'return -ENOSYS' for the '#else' branch, which lets the
other syscalls work as-is and allows developers to fix up the test
failures reported by nolibc-test one by one later.

This wraps all of the failed syscall macros with '#ifdef' and 'return
-ENOSYS' for the '#else' branch, so, all of the undeclared failures are
fixed.

Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://lore.kernel.org/linux-riscv/5e7d2adf-e96f-41ca-a4c6-5c87a25d4c9c@xxxxxxxxxxxxxxxx/
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Zhangjin Wu <falcon@xxxxxxxxxxx>
---
tools/include/nolibc/sys.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 78c86f124335..5464f93e863e 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -554,7 +554,11 @@ long getpagesize(void)
static __attribute__((unused))
int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
{
+#ifdef __NR_gettimeofday
return my_syscall2(__NR_gettimeofday, tv, tz);
+#else
+ return -ENOSYS;
+#endif
}

static __attribute__((unused))
@@ -672,7 +676,11 @@ int link(const char *old, const char *new)
static __attribute__((unused))
off_t sys_lseek(int fd, off_t offset, int whence)
{
+#ifdef __NR_lseek
return my_syscall3(__NR_lseek, fd, offset, whence);
+#else
+ return -ENOSYS;
+#endif
}

static __attribute__((unused))
@@ -1338,7 +1346,11 @@ int unlink(const char *path)
static __attribute__((unused))
pid_t sys_wait4(pid_t pid, int *status, int options, struct rusage *rusage)
{
+#ifdef __NR_wait4
return my_syscall4(__NR_wait4, pid, status, options, rusage);
+#else
+ return -ENOSYS;
+#endif
}

static __attribute__((unused))
--
2.25.1