Stop-hooks weren't getting called on step-out. Fix that.

There was a little bit of logic in the StopInfoBreakpoint::PerformAction
that would null out the StopInfo once we had a completed plan so that the
next call to GetStopInfo would replace it with the StopInfoThreadPlan.

But the stop-hooks check for whether a thread stopped for a reason didn't
trigger this conversion.  So I added an API to do that directly, and then
called it where before we just reset the StopInfo.

<rdar://problem/54270767>

Differential Revision: https://reviews.llvm.org/D66241

llvm-svn: 369052

lldb/include/lldb/Target/Thread.h

@@ -1101,6 +1101,17 @@ class Thread : public std::enable_shared_from_this<Thread>,
   // right even if you have not calculated this yourself, or if it disagrees
   // with what you might have calculated.
   virtual lldb::StopInfoSP GetPrivateStopInfo();
+
+  // Calculate the stop info that will be shown to lldb clients.  For instance,
+  // a "step out" is implemented by running to a breakpoint on the function 
+  // return PC, so the process plugin initially sets the stop info to a
+  // StopInfoBreakpoint. But once we've run the ShouldStop machinery, we
+  // discover that there's a completed ThreadPlanStepOut, and that's really
+  // the StopInfo we want to show.  That will happen naturally the next
+  // time GetStopInfo is called, but if you want to force the replacement,
+  // you can call this.
+
+  void CalculatePublicStopInfo();
 
   // Ask the thread subclass to set its stop info.
   //

lldb/packages/Python/lldbsuite/test/functionalities/stop-hooks/Makefile

@@ -0,0 +1,6 @@
+LEVEL = ../../make
+
+C_SOURCES := main.c
+CFLAGS_EXTRAS += -std=c99
+
+include $(LEVEL)/Makefile.rules

lldb/packages/Python/lldbsuite/test/functionalities/stop-hooks/TestStopHooks.py

@@ -0,0 +1,45 @@
+"""
+Test that stop hooks trigger on "step-out"
+"""
+
+from __future__ import print_function
+
+
+import lldb
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbtest import *
+
+
+class TestStopHooks(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    # If your test case doesn't stress debug info, the
+    # set this to true.  That way it won't be run once for
+    # each debug info format.
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def test_stop_hooks_step_out(self):
+        """Test that stop hooks fire on step-out."""
+        self.build()
+        self.main_source_file = lldb.SBFileSpec("main.c")
+        self.step_out_test()
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+
+    def step_out_test(self):
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(self,
+                                   "Set a breakpoint here", self.main_source_file)
+
+        interp = self.dbg.GetCommandInterpreter()
+        result = lldb.SBCommandReturnObject()
+        interp.HandleCommand("target stop-hook add -o 'expr g_var++'", result)
+        self.assertTrue(result.Succeeded, "Set the target stop hook")
+        thread.StepOut()
+        var = target.FindFirstGlobalVariable("g_var")
+        self.assertTrue(var.IsValid())
+        self.assertEqual(var.GetValueAsUnsigned(), 1, "Updated g_var")
+
+

lldb/packages/Python/lldbsuite/test/functionalities/stop-hooks/main.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+static int g_var = 0;
+
+int step_out_of_me()
+{
+  return g_var; // Set a breakpoint here and step out.
+}
+
+int
+main()
+{
+  return step_out_of_me();
+}

lldb/source/Target/StopInfo.cpp

@@ -543,10 +543,10 @@ class StopInfoBreakpoint : public StopInfo {
         // additionally to the breakpoint
         m_should_stop = true;
 
-        // Here we clean the preset stop info so the next GetStopInfo call will
-        // find the appropriate stop info, which should be the stop info
-        // related to the completed plan
-        thread_sp->ResetStopInfo();
+        // We know we're stopping for a completed plan and we don't want to
+        // show the breakpoint stop, so compute the public stop info immediately
+        // here.
+        thread_sp->CalculatePublicStopInfo();
       }
 
       LLDB_LOGF(log,

lldb/source/Target/Thread.cpp

@@ -390,6 +390,11 @@ lldb::StopInfoSP Thread::GetStopInfo() {
   }
 }
 
+void Thread::CalculatePublicStopInfo() {
+  ResetStopInfo();
+  SetStopInfo(GetStopInfo());
+}
+
 lldb::StopInfoSP Thread::GetPrivateStopInfo() {
   if (m_destroy_called)
     return m_stop_info_sp;