Sanitizers: Implement `GetRSS` on Mac OS X

[dvyukov]

lib/sanitizer_common/sanitizer_mac.cc

341

We don't use C89 declaration style, so please do:
unsigned count = ...
and the same for the other variables.

345

Is it really can happen? Or it is more like "this should never happen"?
If it the latter, then make it fatal by calling Die(). Otherwise print only in verbose more (I think we now have VPrintf(1, "..."). Whenever we print something in normal operation mode, some programs fail. Consider a generator program, this output will become part of generated output and will necessary fail the rest of the test.

347

s/0U/0/ please
0 should convert to uptr just fine. This code is compiled with -Wall by two compilers clean, that should catch any conversion bugs.

[ismailp]

Addressed comments.

[glider]

LGTM with two nits.

lib/sanitizer_common/sanitizer_mac.cc

47

While at it, can you please sort this block of includes alphabetically?

343

NB: currently task_info() can't possibly return anything but KERN_SUCCESS, so it's perfectly fine to die.

345

Nit: spare newline.

[dvyukov]

LGTM

[ismailp]

• Sort includes alphabetically
• Remove newline in GetRSS

[ismailp]

Thank you both for your time!

lib/sanitizer_common/sanitizer_mac.cc

 #include <sys/mman.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <libkern/OSAtomic.h>
 #include <errno.h>
+#include <mach/mach.h>
 
 namespace __sanitizer {
 
 #include "sanitizer_syscall_generic.inc"
 
 // ---------------------- sanitizer_libc.h
 uptr internal_mmap(void *addr, size_t length, int prot, int flags,
                    int fd, u64 offset) {
MacosVersion GetMacosVersion() {
   if (result == MACOS_VERSION_UNINITIALIZED) {
     result = GetMacosVersionInternal();
     atomic_store(cache, result, memory_order_release);
   }
   return result;
 }
 
 uptr GetRSS() {
-  return 0;
+  kern_return_t result;
+  unsigned count;
+  struct task_basic_info info;
+
+  count = TASK_BASIC_INFO_COUNT;
+  result =
+      task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &count);
+  if (UNLIKELY(result != KERN_SUCCESS)) {
+    Report("Could not get task info - RSS value will not be available. "
+           "Error: %d\n", result);
+    return 0U;
+  }
+
+  return info.resident_size;
 }
 
 void *internal_start_thread(void (*func)(void *arg), void *arg) { return 0; }
 void internal_join_thread(void *th) { }
 
 void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   ucontext_t *ucontext = (ucontext_t*)context;
 # if SANITIZER_WORDSIZE == 64