Add a darwin platform setting to specify which exceptions debugserver

should not receive as exceptions (some will get converted to BSD
signals instead).  This is really the only stable way to ensure that
a Mach exception gets converted to it's equivalent BSD signal.  For
programs that rely on BSD signal handlers, this has to happen or you
can't even get the program to invoke the signal handler when under
the debugger.

This builds on a previous solution to this problem which required you
start debugserver with the -U flag.  This was not very discoverable
and required lldb be the one to launch debugserver, which is not always
the case.

Differential Revision: https://reviews.llvm.org/D125434

1 files changed, 16 insertions, 5 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index f7e2188..a00961d 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -954,12 +954,23 @@ Status ProcessGDBRemote::ConnectToDebugserver(llvm::StringRef connect_url) {
   m_gdb_comm.GetVAttachOrWaitSupported();
   m_gdb_comm.EnableErrorStringInPacket();
 
-  size_t num_cmds = GetExtraStartupCommands().GetArgumentCount();
-  for (size_t idx = 0; idx < num_cmds; idx++) {
-    StringExtractorGDBRemote response;
-    m_gdb_comm.SendPacketAndWaitForResponse(
-        GetExtraStartupCommands().GetArgumentAtIndex(idx), response);
+  // First dispatch any commands from the platform:
+  auto handle_cmds = [&] (const Args &args) ->  void {
+    for (const Args::ArgEntry &entry : args) {
+      StringExtractorGDBRemote response;
+      m_gdb_comm.SendPacketAndWaitForResponse(
+          entry.c_str(), response);
+    }
+  };
+  
+  PlatformSP platform_sp = GetTarget().GetPlatform();
+  if (platform_sp) {
+    handle_cmds(platform_sp->GetExtraStartupCommands());
   }
+  
+  // Then dispatch any process commands:
+  handle_cmds(GetExtraStartupCommands());
+
   return error;
 }