Make some small Mac-specific modifications to V8 to make it work on MacOS X 1...

src/platform-macos.cc

 // Copyright 2006-2008 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 17 matching lines @@
 // Platform specific code for MacOS goes here. For the POSIX comaptible parts
 // the implementation is in platform-posix.cc.
 
 #include <ucontext.h>
 #include <unistd.h>
 #include <sys/mman.h>
 #include <mach/mach_init.h>
 
 #include <AvailabilityMacros.h>
 
-#ifdef MAC_OS_X_VERSION_10_5
-# include <execinfo.h>  // backtrace, backtrace_symbols
-#endif
-
 #include <pthread.h>
 #include <semaphore.h>
 #include <signal.h>
 #include <mach/semaphore.h>
 #include <mach/task.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/types.h>
 #include <stdarg.h>
 #include <stdlib.h>
 
 #include <errno.h>
 
 #undef MAP_TYPE
 
 #include "v8.h"
 
 #include "platform.h"
 
+// Manually define these here as weak imports, rather than including execinfo.h.
+// This lets us launch on 10.4 which does not have these calls.
+extern "C" {
+  extern int backtrace(void**, int) __attribute__((weak_import));
+  extern char** backtrace_symbols(void* const*, int)
+      __attribute__((weak_import));
+  extern void backtrace_symbols_fd(void* const*, int, int)
+      __attribute__((weak_import));
+}
+
+
 namespace v8 {
 namespace internal {
 
 // 0 is never a valid thread id on MacOSX since a ptread_t is
 // a pointer.
 static const pthread_t kNoThread = (pthread_t) 0;
 
 
 double ceiling(double x) {
   // Correct Mac OS X Leopard 'ceil' behavior.
@@ skipping 136 matching lines @@
 
 
 int OS::ActivationFrameAlignment() {
   // OS X activation frames must be 16 byte-aligned; see "Mac OS X ABI
   // Function Call Guide".
   return 16;
 }
 
 
 int OS::StackWalk(Vector<StackFrame> frames) {
-#ifndef MAC_OS_X_VERSION_10_5
-  return 0;
-#else
+  // If weak link to execinfo lib has failed, ie because we are on 10.4, abort.
+  if (backtrace == NULL)
+    return 0;
+
   int frames_size = frames.length();
   void** addresses = NewArray<void*>(frames_size);
   int frames_count = backtrace(addresses, frames_size);
 
   char** symbols;
   symbols = backtrace_symbols(addresses, frames_count);
   if (symbols == NULL) {
     DeleteArray(addresses);
     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';
   }
 
   DeleteArray(addresses);
   free(symbols);
 
   return frames_count;
-#endif
 }
 
 
 // Constants used for mmap.
 static const int kMmapFd = -1;
 static const int kMmapFdOffset = 0;
 
 
 VirtualMemory::VirtualMemory(size_t size) {
   address_ = mmap(NULL, size, PROT_NONE,
@@ skipping 311 matching lines @@
   }
 
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
   active_ = false;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal