Make sure that stop-hooks run asynchronously.

They aren't designed to nest recursively, so this will prevent that.
Also add a --auto-continue flag, putting "continue" in the stop hook makes
the stop hooks fight one another in multi-threaded programs.
Also allow more than one -o options so you can make more complex stop hooks w/o
having to go into the editor.

<rdar://problem/48115661>

Differential Revision: https://reviews.llvm.org/D58394

llvm-svn: 354706

lldb/include/lldb/Target/Process.h

@@ -2519,6 +2519,8 @@ class Process : public std::enable_shared_from_this<Process>,
   ///
   //------------------------------------------------------------------
   void RestoreProcessEvents();
+
+  bool IsHijackedForSynchronousResume();
 
   const lldb::ABISP &GetABI();
 

lldb/include/lldb/Target/Target.h

@@ -1153,14 +1153,19 @@ class Target : public std::enable_shared_from_this<Target>,
 
     void SetIsActive(bool is_active) { m_active = is_active; }
 
+    void SetAutoContinue(bool auto_continue) {m_auto_continue = auto_continue;}
+
+    bool GetAutoContinue() const { return m_auto_continue; }
+
     void GetDescription(Stream *s, lldb::DescriptionLevel level) const;
 
   private:
     lldb::TargetSP m_target_sp;
     StringList m_commands;
     lldb::SymbolContextSpecifierSP m_specifier_sp;
     std::unique_ptr<ThreadSpec> m_thread_spec_up;
-    bool m_active;
+    bool m_active = true;
+    bool m_auto_continue = false;
 
     // Use CreateStopHook to make a new empty stop hook. The GetCommandPointer
     // and fill it with commands, and SetSpecifier to set the specifier shared

lldb/lit/ExecControl/StopHook/Inputs/stop-hook-2.lldbinit

@@ -1 +1 @@
-target stop-hook add -f stop-hook.c -l 29 -e 34 -o "expr ptr"
+target stop-hook add -f stop-hook.c -l 29 -e 34 -o "expr ptr"

lldb/lit/ExecControl/StopHook/Inputs/stop-hook-3.lldbinit

@@ -1,3 +1,3 @@
 target stop-hook add -f stop-hook.c -l 29 -e 34
 expr ptr
-DONE
+DONE

lldb/lit/ExecControl/StopHook/Inputs/stop-hook-threads-1.lldbinit

@@ -1,7 +1,7 @@
+break set -f stop-hook-threads.cpp -p "Break here to set up the stop hook"
 break set -f stop-hook-threads.cpp -p "Break here to test that the stop-hook"
 run
-target stop-hook add
-frame variable --show-globals g_val
+target stop-hook add -G true
+expr lldb_val += 1
 thread list
-continue
 DONE

lldb/lit/ExecControl/StopHook/Inputs/stop-hook-threads-2.lldbinit

@@ -1,4 +1,5 @@
+break set -f stop-hook-threads.cpp -p "Break here to set up the stop hook"
 break set -f stop-hook-threads.cpp -p "Break here to test that the stop-hook"
 run
-target stop-hook add -x 2 -o "frame variable thread_index"
-target stop-hook add -o continue
+target stop-hook add -x 2 -o "expr lldb_val += 1" -o "thread list"
+target stop-hook add -G true -o "script print('Hit stop hook') 

lldb/lit/ExecControl/StopHook/Inputs/stop-hook-threads.cpp

@@ -16,6 +16,7 @@ std::default_random_engine g_random_engine{std::random_device{}()};
 std::uniform_int_distribution<> g_distribution{0, 3000};
 
 uint32_t g_val = 0;
+uint32_t lldb_val = 0;
 
 uint32_t
 access_pool (bool flag = false)
@@ -62,7 +63,8 @@ thread_func (uint32_t thread_index)
 int main (int argc, char const *argv[])
 {
     std::thread threads[3];
-
+    // Break here to set up the stop hook
+    printf("Stop hooks engaged.\n");
     // Create 3 threads
     for (auto &thread : threads)
         thread = std::thread{thread_func, std::distance(threads, &thread)};
@@ -71,5 +73,7 @@ int main (int argc, char const *argv[])
     for (auto &thread : threads)
         thread.join();
 
+    // print lldb_val so we can check it here.
+    printf ("lldb_val was set to: %d.\n", lldb_val);
     return 0;
 }

lldb/lit/ExecControl/StopHook/stop-hook-threads.test

@@ -4,31 +4,29 @@
 # RUN: %lldb -b -s %p/Inputs/stop-hook-threads-2.lldbinit -s %s -f %t \
 # RUN:     | FileCheck --check-prefix=CHECK --check-prefix=CHECK-FILTER %s
 # XFAIL: system-windows
-# UNSUPPORTED: linux
 
 thread list
 break set -f stop-hook-threads.cpp -p "Set break point at this line"
 target stop-hook list
 
 # CHECK: Hook: 1
 # CHECK-NEXT:  State: enabled
+# CHECK-NO-FILTER-NEXT: AutoContinue on
 # CHECK-FILTER-NEXT:  Thread
 # CHECK-FILTER-NEXT:  index: 2
 # CHECK-NEXT:  Commands: 
-# CHECK-NEXT:    frame variable
+# CHECK-NEXT:    expr lldb_val += 1
+# CHECK-NEXT:    thread list
 
 # CHECK-FILTER: Hook: 2
 # CHECK-FILTER-NEXT:  State: enabled
+# CHECK-FILTER-NEXT:  AutoContinue on
 # CHECK-FILTER-NEXT:  Commands: 
-# CHECK-FILTER-NEXT:    continue
+# CHECK-FILTER-NEXT:    script print('Hit stop hook')
 
 # Get the threads going
 continue
 
-# When we filter per thread, we expect exactly 4 identical "frame var" results
-# CHECK-FILTER: (uint32_t) thread_index = [[THREAD_INDEX:[0-9]*]]
-# CHECK-FILTER-COUNT-3: (uint32_t) thread_index = [[THREAD_INDEX]]
-# CHECK-FILTER-NOT: thread_index
-
-# When we don't filter, we expect to count 12 stopped threads in the thread list output
-# CHECK-NO-FILTER-COUNT-12: at stop-hook-threads.cpp{{.*}} stop reason = breakpoint
+# Now make sure we hit the command the right number of times:
+# CHECK-NO-FILTER: lldb_val was set to: 15.
+# CHECK-FILTER: lldb_val was set to: 5.

lldb/lit/ExecControl/StopHook/stop-hook.test

@@ -11,6 +11,7 @@
 # string, so the test "passes" despite the fact that the commands failed
 # llvm.org/pr40119
 # UNSUPPORTED: system-windows
+# XFAIL: system-linux
 
 break set -f stop-hook.c -p "// Set breakpoint here to test target stop-hook"
 break set -f stop-hook.c -p "// Another breakpoint which is outside of the stop-hook range"

lldb/source/Commands/CommandObjectTarget.cpp

@@ -4555,7 +4555,7 @@ class CommandObjectTargetSymbols : public CommandObjectMultiword {
 
 static constexpr OptionDefinition g_target_stop_hook_add_options[] = {
     // clang-format off
-  { LLDB_OPT_SET_ALL, false, "one-liner",    'o', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeOneLiner,                                         "Specify a one-line breakpoint command inline. Be sure to surround it with quotes." },
+  { LLDB_OPT_SET_ALL, false, "one-liner",    'o', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeOneLiner,                                         "Add a command for the stop hook.  Can be specified more than once, and commands will be run in the order they appear." },
   { LLDB_OPT_SET_ALL, false, "shlib",        's', OptionParser::eRequiredArgument, nullptr, {}, CommandCompletions::eModuleCompletion, eArgTypeShlibName,    "Set the module within which the stop-hook is to be run." },
   { LLDB_OPT_SET_ALL, false, "thread-index", 'x', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeThreadIndex,                                      "The stop hook is run only for the thread whose index matches this argument." },
   { LLDB_OPT_SET_ALL, false, "thread-id",    't', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeThreadID,                                         "The stop hook is run only for the thread whose TID matches this argument." },
@@ -4566,6 +4566,7 @@ static constexpr OptionDefinition g_target_stop_hook_add_options[] = {
   { LLDB_OPT_SET_1,   false, "end-line",     'e', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeLineNum,                                          "Set the end of the line range for which the stop-hook is to be run." },
   { LLDB_OPT_SET_2,   false, "classname",    'c', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeClassName,                                        "Specify the class within which the stop-hook is to be run." },
   { LLDB_OPT_SET_3,   false, "name",         'n', OptionParser::eRequiredArgument, nullptr, {}, CommandCompletions::eSymbolCompletion, eArgTypeFunctionName, "Set the function name within which the stop hook will be run." },
+  { LLDB_OPT_SET_ALL, false, "auto-continue",'G', OptionParser::eRequiredArgument, nullptr, {}, 0, eArgTypeBoolean,     "The breakpoint will auto-continue after running its commands." },
     // clang-format on
 };
 
@@ -4606,6 +4607,17 @@ class CommandObjectTargetStopHookAdd : public CommandObjectParsed,
         m_sym_ctx_specified = true;
         break;
 
+      case 'G': {
+        bool value, success;
+        value = OptionArgParser::ToBoolean(option_arg, false, &success);
+        if (success) {
+          m_auto_continue = value;
+        } else
+          error.SetErrorStringWithFormat(
+              "invalid boolean value '%s' passed for -G option",
+              option_arg.str().c_str());
+      }
+      break;
       case 'l':
         if (option_arg.getAsInteger(0, m_line_start)) {
           error.SetErrorStringWithFormat("invalid start line number: \"%s\"",
@@ -4661,7 +4673,7 @@ class CommandObjectTargetStopHookAdd : public CommandObjectParsed,
 
       case 'o':
         m_use_one_liner = true;
-        m_one_liner = option_arg;
+        m_one_liner.push_back(option_arg);
         break;
 
       default:
@@ -4690,6 +4702,7 @@ class CommandObjectTargetStopHookAdd : public CommandObjectParsed,
 
       m_use_one_liner = false;
       m_one_liner.clear();
+      m_auto_continue = false;
     }
 
     std::string m_class_name;
@@ -4708,7 +4721,8 @@ class CommandObjectTargetStopHookAdd : public CommandObjectParsed,
     bool m_thread_specified;
     // Instance variables to hold the values for one_liner options.
     bool m_use_one_liner;
-    std::string m_one_liner;
+    std::vector<std::string> m_one_liner;
+    bool m_auto_continue;
   };
 
   CommandObjectTargetStopHookAdd(CommandInterpreter &interpreter)
@@ -4833,10 +4847,13 @@ class CommandObjectTargetStopHookAdd : public CommandObjectParsed,
 
         new_hook_sp->SetThreadSpecifier(thread_spec);
       }
+
+      new_hook_sp->SetAutoContinue(m_options.m_auto_continue);
       if (m_options.m_use_one_liner) {
-        // Use one-liner.
-        new_hook_sp->GetCommandPointer()->AppendString(
-            m_options.m_one_liner.c_str());
+        // Use one-liners.
+        for (auto cmd : m_options.m_one_liner)
+          new_hook_sp->GetCommandPointer()->AppendString(
+            cmd.c_str());
         result.AppendMessageWithFormat("Stop hook #%" PRIu64 " added.\n",
                                        new_hook_sp->GetID());
       } else {

lldb/source/Target/Process.cpp

@@ -1615,6 +1615,8 @@ Status Process::Resume() {
   return error;
 }
 
+static const char *g_resume_sync_name = "lldb.Process.ResumeSynchronous.hijack";
+
 Status Process::ResumeSynchronous(Stream *stream) {
   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_STATE |
                                                   LIBLLDB_LOG_PROCESS));
@@ -1628,7 +1630,7 @@ Status Process::ResumeSynchronous(Stream *stream) {
   }
 
   ListenerSP listener_sp(
-      Listener::MakeListener("lldb.Process.ResumeSynchronous.hijack"));
+      Listener::MakeListener(g_resume_sync_name));
   HijackProcessEvents(listener_sp);
 
   Status error = PrivateResume();
@@ -1652,6 +1654,11 @@ Status Process::ResumeSynchronous(Stream *stream) {
   return error;
 }
 
+bool Process::IsHijackedForSynchronousResume() {
+  const char *hijacker_name = GetHijackingListenerName();
+  return strcmp(hijacker_name, g_resume_sync_name) == 0;
+}
+
 StateType Process::GetPrivateState() { return m_private_state.GetValue(); }
 
 void Process::SetPrivateState(StateType new_state) {
@@ -4260,11 +4267,20 @@ void Process::ProcessEventData::DoOnRemoval(Event *event_ptr) {
         // public resume.
         process_sp->PrivateResume();
       } else {
-        // If we didn't restart, run the Stop Hooks here: They might also
-        // restart the target, so watch for that.
-        process_sp->GetTarget().RunStopHooks();
-        if (process_sp->GetPrivateState() == eStateRunning)
-          SetRestarted(true);
+        bool hijacked = 
+            process_sp->IsHijackedForEvent(eBroadcastBitStateChanged)
+            && !process_sp->IsHijackedForSynchronousResume();
+
+        if (!hijacked) {
+          // If we didn't restart, run the Stop Hooks here.
+          // Don't do that if state changed events aren't hooked up to the
+          // public (or SyncResume) broadcasters.  StopHooks are just for 
+          // real public stops.  They might also restart the target, 
+          // so watch for that.
+          process_sp->GetTarget().RunStopHooks();
+          if (process_sp->GetPrivateState() == eStateRunning)
+            SetRestarted(true);
+        }
       }
     }
   }

lldb/source/Target/Target.cpp

@@ -2554,12 +2554,14 @@ void Target::RunStopHooks() {
 
   StopHookCollection::iterator pos, end = m_stop_hooks.end();
 
-  // If there aren't any active stop hooks, don't bother either:
+  // If there aren't any active stop hooks, don't bother either.
+  // Also see if any of the active hooks want to auto-continue.
   bool any_active_hooks = false;
-  for (pos = m_stop_hooks.begin(); pos != end; pos++) {
-    if ((*pos).second->IsActive()) {
+  bool auto_continue = false;
+  for (auto hook : m_stop_hooks) {
+    if (hook.second->IsActive()) {
       any_active_hooks = true;
-      break;
+      auto_continue |= hook.second->GetAutoContinue();
     }
   }
   if (!any_active_hooks)
@@ -2595,6 +2597,7 @@ void Target::RunStopHooks() {
   bool hooks_ran = false;
   bool print_hook_header = (m_stop_hooks.size() != 1);
   bool print_thread_header = (num_exe_ctx != 1);
+  bool did_restart = false;
 
   for (pos = m_stop_hooks.begin(); keep_going && pos != end; pos++) {
     // result.Clear();
@@ -2639,10 +2642,13 @@ void Target::RunStopHooks() {
         options.SetPrintResults(true);
         options.SetAddToHistory(false);
 
+        // Force Async:
+        bool old_async = GetDebugger().GetAsyncExecution();
+        GetDebugger().SetAsyncExecution(true);
         GetDebugger().GetCommandInterpreter().HandleCommands(
             cur_hook_sp->GetCommands(), &exc_ctx_with_reasons[i], options,
             result);
-
+        GetDebugger().SetAsyncExecution(old_async);
         // If the command started the target going again, we should bag out of
         // running the stop hooks.
         if ((result.GetStatus() == eReturnStatusSuccessContinuingNoResult) ||
@@ -2651,13 +2657,19 @@ void Target::RunStopHooks() {
           StopHookCollection::iterator tmp = pos;
           if (++tmp != end)
             result.AppendMessageWithFormat("\nAborting stop hooks, hook %" PRIu64
-                                           " set the program running.\n",
+                                           " set the program running.\n"
+                                           "  Consider using '-G true' to make "
+                                           "stop hooks auto-continue.\n",
                                            cur_hook_sp->GetID());
           keep_going = false;
+          did_restart = true;
         }
       }
     }
   }
+  // Finally, if auto-continue was requested, do it now:
+  if (!did_restart && auto_continue)
+    m_process_sp->PrivateResume();
 
   result.GetImmediateOutputStream()->Flush();
   result.GetImmediateErrorStream()->Flush();
@@ -3143,12 +3155,13 @@ void Target::FinalizeFileActions(ProcessLaunchInfo &info) {
 //--------------------------------------------------------------
 Target::StopHook::StopHook(lldb::TargetSP target_sp, lldb::user_id_t uid)
     : UserID(uid), m_target_sp(target_sp), m_commands(), m_specifier_sp(),
-      m_thread_spec_up(), m_active(true) {}
+      m_thread_spec_up() {}
 
 Target::StopHook::StopHook(const StopHook &rhs)
     : UserID(rhs.GetID()), m_target_sp(rhs.m_target_sp),
       m_commands(rhs.m_commands), m_specifier_sp(rhs.m_specifier_sp),
-      m_thread_spec_up(), m_active(rhs.m_active) {
+      m_thread_spec_up(), m_active(rhs.m_active),
+      m_auto_continue(rhs.m_auto_continue) {
   if (rhs.m_thread_spec_up)
     m_thread_spec_up.reset(new ThreadSpec(*rhs.m_thread_spec_up));
 }
@@ -3175,6 +3188,9 @@ void Target::StopHook::GetDescription(Stream *s,
   else
     s->Indent("State: disabled\n");
 
+  if (m_auto_continue)
+    s->Indent("AutoContinue on\n");
+
   if (m_specifier_sp) {
     s->Indent();
     s->PutCString("Specifier:\n");