Fix/workaround for OS X truncated stacktraces taken by external tools

This patch is a proposed solution for https://code.google.com/p/address-sanitizer/issues/detail?id=375:

When the stacktraces are captured and printed by ASan itself, they are fine, but when the program has already printed the report (or is just printing it), capturing a stacktrace via other means is broken. "Other means" include OS X CrashReporter, debuggers or calling backtrace() within the program. For example calling backtrace() from a sanitizer_set_death_callback function prints a very truncated stacktrace.

Reviewed at http://reviews.llvm.org/D7103



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@226878 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 43 insertions, 0 deletions

diff --git a/test/asan/TestCases/Darwin/crashlog-stacktraces.c b/test/asan/TestCases/Darwin/crashlog-stacktraces.c
new file mode 100644
index 000000000..e9af5396e
--- /dev/null
+++ b/test/asan/TestCases/Darwin/crashlog-stacktraces.c
@@ -0,0 +1,43 @@
+// RUN: %clang_asan -O0 %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s
+
+#include <execinfo.h>
+#include <sanitizer/common_interface_defs.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void death_function() {
+  fprintf(stderr, "DEATH CALLBACK\n");
+
+  void* callstack[128];
+  int i, frames = backtrace(callstack, 128);
+  char** strs = backtrace_symbols(callstack, frames);
+  for (i = 0; i < frames; ++i) {
+    fprintf(stderr, "%s\n", strs[i]);
+  }
+  free(strs);
+
+  fprintf(stderr, "END OF BACKTRACE\n");
+}
+
+int fault_function() {
+  char *x = (char*)malloc(10 * sizeof(char));
+  free(x);
+  return x[5];  // BOOM
+}
+
+int main() {
+  __sanitizer_set_death_callback(death_function);
+  fault_function();
+  return 0;
+}
+
+// CHECK: {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+// CHECK: {{READ of size 1 at 0x.* thread T0}}
+// CHECK: {{    #0 0x.* in fault_function}}
+
+// CHECK: DEATH CALLBACK
+// CHECK: death_function
+// CHECK: fault_function
+// CHECK: main
+// CHECK: END OF BACKTRACE