v8: fix dragonflybsd build

src/platform-freebsd.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 25 matching lines @@
 #include <sys/types.h>
 #include <sys/ucontext.h>
 #include <stdlib.h>
 
 #include <sys/types.h>  // mmap & munmap
 #include <sys/mman.h>   // mmap & munmap
 #include <sys/stat.h>   // open
 #include <sys/fcntl.h>  // open
 #include <unistd.h>     // getpagesize
 // If you don't have execinfo.h then you need devel/libexecinfo from ports.
-#include <execinfo.h>   // backtrace, backtrace_symbols
 #include <strings.h>    // index
 #include <errno.h>
 #include <stdarg.h>
 #include <limits.h>
 
+#if !defined(__DragonFly__)

[Sven Panne, 2013/01/02 08:06:46]

One general comment about such #ifs: Instead of scattering obscure platform
#ifdefs all over the place, please use feature-based #ifdefs and #define the
corresponding preprocessor symbol at a single central place. In our concrete
example:

Use

   #ifdef HAVE_EXECINFO_H
   #include <execinfo.h>
   #endif

here and similar conditionals in the changes below. Make sure that
HAVE_EXECINFO_H is defined where it is available, e.g. via our GYP files.

Doing it this way has the advantage that the code is much, much easier to read
an maintain. I know that the current v8 code is guilty of doing this massively
wrong already, but we shouldn't make it worse... :-)

+#include <execinfo.h>   // backtrace, backtrace_symbols
+#endif
+
 #undef MAP_TYPE
 
 #include "v8.h"
 #include "v8threads.h"
 
 #include "platform-posix.h"
 #include "platform.h"
 #include "vm-state-inl.h"
 
 
@@ skipping 227 matching lines @@
   }
   close(fd);
 }
 
 
 void OS::SignalCodeMovingGC() {
 }
 
 
 int OS::StackWalk(Vector<OS::StackFrame> frames) {
+#if defined(__DragonFly__)
+  return 0;
+#else
   int frames_size = frames.length();
   ScopedVector<void*> addresses(frames_size);
 
   int frames_count = backtrace(addresses.start(), frames_size);
 
   char** symbols = backtrace_symbols(addresses.start(), frames_count);
   if (symbols == NULL) {
     return kStackWalkError;
   }
 
   for (int i = 0; i < frames_count; i++) {
     frames[i].address = addresses[i];
     // Format a text representation of the frame based on the information
     // available.
     SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen),
              "%s",
              symbols[i]);
     // Make sure line termination is in place.
     frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
   }
 
   free(symbols);
 
   return frames_count;
+#endif
 }
 
 
 // Constants used for mmap.
 static const int kMmapFd = -1;
 static const int kMmapFdOffset = 0;
 
 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
 
 VirtualMemory::VirtualMemory(size_t size) {
@@ skipping 278 matching lines @@
 void FreeBSDSemaphore::Wait() {
   while (true) {
     int result = sem_wait(&sem_);
     if (result == 0) return;  // Successfully got semaphore.
     CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
   }
 }
 
 
 bool FreeBSDSemaphore::Wait(int timeout) {
+#if defined(__DragonFly__)
+  /* DragonFlyBSD lacks sem_timedwait() and there is no good way to emulate it.
+   */
+  if (sem_wait(&sem_)) abort();
+  USE(timeout);
+  return true;
+#else
   const long kOneSecondMicros = 1000000;  // NOLINT
 
   // Split timeout into second and nanosecond parts.
   struct timeval delta;
   delta.tv_usec = timeout % kOneSecondMicros;
   delta.tv_sec = timeout / kOneSecondMicros;
 
   struct timeval current_time;
   // Get the current time.
   if (gettimeofday(&current_time, NULL) == -1) {
     return false;
   }
 
   // Calculate time for end of timeout.
   struct timeval end_time;
   timeradd(&current_time, &delta, &end_time);
 
   struct timespec ts;
   TIMEVAL_TO_TIMESPEC(&end_time, &ts);
   while (true) {
     int result = sem_timedwait(&sem_, &ts);
     if (result == 0) return true;  // Successfully got semaphore.
     if (result == -1 && errno == ETIMEDOUT) return false;  // Timeout.
     CHECK(result == -1 && errno == EINTR);  // Signal caused spurious wakeup.
   }
+#endif
 }
 
 
 Semaphore* OS::CreateSemaphore(int count) {
   return new FreeBSDSemaphore(count);
 }
 
 
 static pthread_t GetThreadID() {
   pthread_t thread_id = pthread_self();
@@ skipping 256 matching lines @@
 
 void Sampler::StartSampling() {
 }
 
 
 void Sampler::StopSampling() {
 }
 
 
 } }  // namespace v8::internal