[PATCH] [compiler-rt] bug 23600 - sanitizer stack trace pc off by 1

[Kostya Serebryany]

================
Comment at: lib/sanitizer_common/sanitizer_stacktrace.h:47
@@ +46,3 @@
+  // Nonzero if the stack trace was generated in response to a signal.
+  bool signaled;
+
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kcc wrote:
> I frankly don't remember is there is a reason to keep StackTrace <= 16 bytes. 
> Let me check later today. 
Note that the StackTrace is copied into the StackDepot and the signalled bit will be lost there. 
I'd guess that instead of adding a new field we should add a new tag type to lib/sanitizer_common/sanitizer_stacktrace.h, e.g. TAG_SIGNAL.
(If we need it at all)

================
Comment at: test/sanitizer_common/TestCases/print-stack-trace-pc.cc:1
@@ +1,2 @@
+// Run each sanitizer test with XSAN_SYMBOLIZER_PATH pointing at
+// bin/llvm-symbolizer and with XSAN_OPTIONS set to a stack trace
----------------
That's a great test to have, but it is not testing the case with signals, is it?

http://reviews.llvm.org/D10065

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