Only use fast stack unwinding for sanitizers failure reports on FreeBSD

[kutuzov.viktor.84]

lib/sanitizer_common/sanitizer_stacktrace.h

60

'if (SANITIZER_MAC || SANTIIZER_FREEBSD)' gives the 'use of logical '||' with constant operand' kind of warning.

[kcc]

LGTM

[kutuzov.viktor.84]

Closed by commit rL212691 (authored by vkutuzov).

lib/sanitizer_common/sanitizer_stacktrace.h

void CopyFrom(const uptr *src, uptr src_size) {
     size = src_size;
     if (size > kStackTraceMax) size = kStackTraceMax;
     for (uptr i = 0; i < size; i++)
       trace[i] = src[i];
   }
 
   static bool WillUseFastUnwind(bool request_fast_unwind) {
     // Check if fast unwind is available. Fast unwind is the only option on Mac.
+    // It is also the only option on FreeBSD as the slow unwinding that
+    // leverages _Unwind_Backtrace() yields the call stack of the signal's
+    // handler and not of the code that raised the signal (as it does on Linux).
     if (!SANITIZER_CAN_FAST_UNWIND)
       return false;
-    else if (SANITIZER_MAC)
+    else if (SANITIZER_MAC != 0 || SANITIZER_FREEBSD != 0)
       return true;
     return request_fast_unwind;
   }
 
   void Unwind(uptr max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
               uptr stack_bottom, bool request_fast_unwind);
 
   static uptr GetCurrentPc();