Working on reconciling out-of-tree patches to compiler-rt for building for iOS.

[beanz]

Summary

This is one of many changes needed for compiler-rt to get it building on iOS.

This change does the following:

• Don't include crt_externs on iOS (it isn't available)
• Support ARM thread state objects

Note: this change does not enable building for iOS, as there are more changes to come.

[beanz]

Looping in Alexander Potapenko because git blame :-).

[beanz]

Adding Kuba and Justin for review.

[samsonov]

lib/sanitizer_common/sanitizer_mac.cc

33

Please use SANITIZER_IOS instead. It is already defined in sanitizer_platform.h (here and below)

371

Please use indentation in nested #ifs

# if foo
  a = x;
#  if bar
  b = y;
#  else
  b = yy;
#  endif
  c = z;
# endif

[beanz]

Updating based on feedback from samsonov.

[samsonov]

LGTM, though I really think we should move _NSGetEnviron logic to a function.

lib/sanitizer_common/sanitizer_mac.cc

200

We have similar code in asan_mac.cc. Please consider factoring it to a function, which we could call from there instead.

[beanz]

Refactoring reading environ out into a funciton.

[samsonov]

LGTM. Let me know if there are more patches you're blocked on.

lib/sanitizer_common/sanitizer_mac.cc

 #include "sanitizer_flags.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_mac.h"
 #include "sanitizer_placement_new.h"
 #include "sanitizer_platform_limits_posix.h"
 #include "sanitizer_procmaps.h"
 
+#if !SANITIZER_IOS
 #include <crt_externs.h>  // for _NSGetEnviron
+#else
+extern char **environ;
+#endif
+
 #include <errno.h>
 #include <fcntl.h>
 #include <libkern/OSAtomic.h>
 #include <mach-o/dyld.h>
 #include <mach/mach.h>
 #include <pthread.h>
 #include <sched.h>
 #include <signal.h>
if ((GetMacosVersion() >= MACOS_VERSION_MAVERICKS) && at_initialization &&
     }
   }
   void *stackaddr = pthread_get_stackaddr_np(pthread_self());
   *stack_top = (uptr)stackaddr;
   *stack_bottom = *stack_top - stacksize;
 }
 
 const char *GetEnv(const char *name) {
+#if !SANITIZER_IOS
   char ***env_ptr = _NSGetEnviron();
   if (!env_ptr) {
     Report("_NSGetEnviron() returned NULL. Please make sure __asan_init() is "
            "called after libSystem_initializer().\n");
     CHECK(env_ptr);
   }
   char **environ = *env_ptr;
+#endif
   CHECK(environ);
   uptr name_len = internal_strlen(name);
   while (*environ != 0) {
     uptr len = internal_strlen(*environ);
     if (len > name_len) {
       const char *p = *environ;
       if (!internal_memcmp(p, name, name_len) &&
           p[name_len] == '=') {  // Match.
uptr GetRSS() {
   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
+# if defined(__aarch64__)
+  *pc = ucontext->uc_mcontext->__ss.__pc;
+#   if defined(__IPHONE_8_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_8_0
+  *bp = ucontext->uc_mcontext->__ss.__fp;
+#   else
+  *bp = ucontext->uc_mcontext->__ss.__lr;
+#   endif
+  *sp = ucontext->uc_mcontext->__ss.__sp;
+# elif defined(__x86_64__)
   *pc = ucontext->uc_mcontext->__ss.__rip;
   *bp = ucontext->uc_mcontext->__ss.__rbp;
   *sp = ucontext->uc_mcontext->__ss.__rsp;
-# else
+# elif defined(__arm__)
+  *pc = ucontext->uc_mcontext->__ss.__pc;
+  *bp = ucontext->uc_mcontext->__ss.__r[7];
+  *sp = ucontext->uc_mcontext->__ss.__sp;
+# elif defined(__i386__)
   *pc = ucontext->uc_mcontext->__ss.__eip;
   *bp = ucontext->uc_mcontext->__ss.__ebp;
   *sp = ucontext->uc_mcontext->__ss.__esp;
-# endif  // SANITIZER_WORDSIZE
+# else
+# error "Unknown architecture"
+# endif
 }
 
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC