Rollback trunk to 3.21.15.

src/platform-posix.h

 // 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 21 matching lines @@
 #include <cxxabi.h>
 #endif
 #include <stdio.h>
 
 #include "platform.h"
 
 namespace v8 {
 namespace internal {
 
 // Used by platform implementation files during OS::DumpBacktrace()
+// and OS::StackWalk().
 template<int (*backtrace)(void**, int),
          char** (*backtrace_symbols)(void* const*, int)>
 struct POSIXBacktraceHelper {
   static void DumpBacktrace() {
     void* trace[100];
     int size = backtrace(trace, ARRAY_SIZE(trace));
     char** symbols = backtrace_symbols(trace, size);
     fprintf(stderr, "\n==== C stack trace ===============================\n\n");
     if (size == 0) {
       fprintf(stderr, "(empty)\n");
@@ skipping 13 matching lines @@
           fprintf(stderr, "%s\n", demangled != NULL ? demangled : mangled);
           free(demangled);
         } else {
           fprintf(stderr, "??\n");
         }
       }
     }
     fflush(stderr);
     free(symbols);
   }
+
+  static int StackWalk(Vector<OS::StackFrame> frames) {
+    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 OS::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.
+      OS::SNPrintF(MutableCStrVector(frames[i].text, OS::kStackWalkMaxTextLen),
+                   "%s", symbols[i]);
+      // Make sure line termination is in place.
+      frames[i].text[OS::kStackWalkMaxTextLen - 1] = '\0';
+    }
+
+    free(symbols);
+
+    return frames_count;
+  }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_PLATFORM_POSIX_H_