NativeProcessLinux: Fix handling of raise(SIGTRAP)

In NativeProcessLinux::MonitorSIGTRAP we were asserting that the si_code
value is one of the codes we know about. However, that list was very
incomplete -- for example, we were not handling SI_TKILL/SI_USER,
generated by raise(SIGTRAP). A cursory examination show there are at
least a dozen codes like these that an app can generate, and more can be
added at any point.

So, instead of trying to play catchup, I change the default behavior to
treat an unknown si_code like an ordinary signal. The only reason we
needed to inspect si_code in the first place is because
watchpoint/breakpoints are notified as SIGTRAP, but we already know
about those, and us starting to use a new debug event is far less likely
than somebody introducing a new non-debug event.

I add a test case to TestRaise to verify we are handling raise(SIGTRAP)
in an application properly.

llvm-svn: 307644

1 files changed, 3 insertions, 5 deletions

diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
index 58a5941ac9d..d988ee93a2b 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -796,11 +796,9 @@ void NativeProcessLinux::MonitorSIGTRAP(const siginfo_t &info,
     break;
 
   default:
-    LLDB_LOG(
-        log,
-        "received unknown SIGTRAP stop event ({0}, pid {1} tid {2}, resuming",
-        info.si_code, GetID(), thread.GetID());
-    llvm_unreachable("Unexpected SIGTRAP code!");
+    LLDB_LOG(log, "received unknown SIGTRAP stop event ({0}, pid {1} tid {2}",
+             info.si_code, GetID(), thread.GetID());
+    MonitorSignal(info, thread, false);
     break;
   }
 }