Add NetBSD support in sanitizer_syscall_generic.inc

[krytarowski]

Summary

This adds:

• NetBSD specific aliases for renamed syscalls,
• differentiate internal_syscall, internal_syscall64, internal_syscall_ptr as there are various types of syscalls on NetBSD.

Part of the code inspired by the original work on libsanitizer in GCC 5.4 by Christos Zoulas.

Sponsored by <The NetBSD Foundation>

[krytarowski]

Improve patch for !NetBSD.

[vitalybuka]

lib/sanitizer_common/sanitizer_syscall_generic.inc

20

please move this into the next #if SANITIZER_NETBSD

[krytarowski]

• Union of two NetBSD specific code sections.

lib/sanitizer_common/sanitizer_syscall_generic.inc

 //===-- sanitizer_syscall_generic.inc ---------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
-// Generic implementations of internal_syscall and internal_iserror.
+// Generic implementations of internal_syscall* and internal_iserror.
 //
 //===----------------------------------------------------------------------===//
 
-#if SANITIZER_FREEBSD || SANITIZER_MAC
+#if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
 # define SYSCALL(name) SYS_ ## name
 #else
 # define SYSCALL(name) __NR_ ## name
 #endif
 
-#if (SANITIZER_FREEBSD || SANITIZER_MAC) && defined(__x86_64__)
+#if SANITIZER_NETBSD
+// We use 3 kinds of internal_syscall's for different types of retval in order
+// to address differences in calling conventions (e.g. registers to place the
+// return value in).
+//   - internal_syscall     for 32-bit length (int, pid_t)
+//   - internal_syscall64   for 64-bit length (off_t)
+//   - internal_syscall_ptr for pointer and (s)size_t
+# define  internal_syscall      syscall
+# define  internal_syscall64    __syscall
+// Handle syscall renames manually
+# define SYS_stat SYS___stat50
+# define SYS_lstat SYS___lstat50
+# define SYS_fstat SYS___fstat50
+# define SYS_gettimeofday SYS___gettimeofday50
+# define SYS_wait4 SYS___wait450
+# define SYS_getdents SYS___getdents30
+# define SYS_sigaltstack SYS___sigaltstack14
+# define SYS_sigprocmask SYS___sigprocmask14
+# define SYS_nanosleep SYS___nanosleep50
+# if SANITIZER_WORDSIZE == 64
+#  define internal_syscall_ptr  __syscall
+# else
+#  define internal_syscall_ptr  syscall
+# endif
+#elif defined(__x86_64__) && (SANITIZER_FREEBSD || SANITIZER_MAC)
 # define internal_syscall __syscall
 # else
 # define internal_syscall syscall
 #endif
 
 bool internal_iserror(uptr retval, int *rverrno) {
   if (retval == (uptr)-1) {
     if (rverrno)
       *rverrno = errno;
     return true;
   } else {
     return false;
   }
 }