Common implementation of OS::DumpBacktrace() and OS::StackWalk().

src/platform-macos.cc

Index: src/platform-macos.cc
diff --git a/src/platform-macos.cc b/src/platform-macos.cc
index e8c25fae93ad0cce3ec54a96a50270fc762c47f8..7677507ec59d0a51c5b7d6d0bfc605f75ecdda9e 100644
--- a/src/platform-macos.cc
+++ b/src/platform-macos.cc
@@ -53,6 +53,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <cxxabi.h>
 
 #undef MAP_TYPE
 
@@ -189,7 +190,33 @@ void OS::DebugBreak() {
 
 
 void OS::DumpBacktrace() {
-  // Currently unsupported.
+  // If weak link to execinfo lib has failed, ie because we are on 10.4, abort.
+  if (backtrace == NULL) return;

[Dmitry Lomov (no reviews), 2013/07/12 07:46:02]

This code looks a copy of the code in platform-linux.cc
Can we share it, possibly parameterized with function pointer to backtrace
function?

[Benedikt Meurer, 2013/07/12 07:54:28]

It's basically a copy, yes. Where would we put this template? In
platform-posix.h?

+  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");
+  } else if (symbols == NULL) {
+    fprintf(stderr, "(no symbols)\n");
+  } else {
+    for (int i = 1; i < size; ++i) {
+      fprintf(stderr, "%2d: ", i);
+      char mangled[201];
+      if (sscanf(symbols[i], "%*[^(]%*[(]%200[^)+]", mangled) == 1) {  // NOLINT
+        int status;
+        size_t length;
+        char* demangled = abi::__cxa_demangle(mangled, NULL, &length, &status);
+        fprintf(stderr, "%s\n", demangled ? demangled : mangled);
+        free(demangled);
+      } else {
+        fprintf(stderr, "??\n");
+      }
+    }
+  }
+  fflush(stderr);
+  free(symbols);
 }