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

src/platform-macos.cc

Index: src/platform-macos.cc
===================================================================
--- src/platform-macos.cc	(revision 2055)
+++ src/platform-macos.cc	(working copy)
@@ -35,10 +35,6 @@
 
 #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>
@@ -58,6 +54,17 @@
 
 #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 {
 
@@ -214,9 +221,10 @@
 
 
 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);
@@ -244,7 +252,6 @@
   free(symbols);
 
   return frames_count;
-#endif
 }