Improve SBThread's stepping API using SBError parameter.

Summary: The new methods will allow to get error messages from stepping API.

Reviewers: aprantl, clayborg, labath, jingham

Reviewed By: aprantl, clayborg, jingham

Subscribers: apolyakov, labath, jingham, clayborg, lemo, lldb-commits

Differential Revision: https://reviews.llvm.org/D47991

llvm-svn: 335180
diff --git a/lldb/source/API/SBThread.cpp b/lldb/source/API/SBThread.cpp
index def3b3a..0d25b85 100644
--- a/lldb/source/API/SBThread.cpp
+++ b/lldb/source/API/SBThread.cpp
@@ -633,6 +633,11 @@
 }
 
 void SBThread::StepOver(lldb::RunMode stop_other_threads) {
+  SBError error; // Ignored
+  StepOver(stop_other_threads, error);
+}
+
+void SBThread::StepOver(lldb::RunMode stop_other_threads, SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
 
   std::unique_lock<std::recursive_mutex> lock;
@@ -643,28 +648,29 @@
                 static_cast<void *>(exe_ctx.GetThreadPtr()),
                 Thread::RunModeAsCString(stop_other_threads));
 
-  if (exe_ctx.HasThreadScope()) {
-    Thread *thread = exe_ctx.GetThreadPtr();
-    bool abort_other_plans = false;
-    StackFrameSP frame_sp(thread->GetStackFrameAtIndex(0));
-
-    ThreadPlanSP new_plan_sp;
-    if (frame_sp) {
-      if (frame_sp->HasDebugInformation()) {
-        const LazyBool avoid_no_debug = eLazyBoolCalculate;
-        SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
-        new_plan_sp = thread->QueueThreadPlanForStepOverRange(
-            abort_other_plans, sc.line_entry, sc, stop_other_threads,
-            avoid_no_debug);
-      } else {
-        new_plan_sp = thread->QueueThreadPlanForStepSingleInstruction(
-            true, abort_other_plans, stop_other_threads);
-      }
-    }
-
-    // This returns an error, we should use it!
-    ResumeNewPlan(exe_ctx, new_plan_sp.get());
+  if (!exe_ctx.HasThreadScope()) {
+    error.SetErrorString("this SBThread object is invalid");
+    return;
   }
+
+  Thread *thread = exe_ctx.GetThreadPtr();
+  bool abort_other_plans = false;
+  StackFrameSP frame_sp(thread->GetStackFrameAtIndex(0));
+
+  ThreadPlanSP new_plan_sp;
+  if (frame_sp) {
+    if (frame_sp->HasDebugInformation()) {
+      const LazyBool avoid_no_debug = eLazyBoolCalculate;
+      SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
+      new_plan_sp = thread->QueueThreadPlanForStepOverRange(
+          abort_other_plans, sc.line_entry, sc, stop_other_threads,
+          avoid_no_debug);
+    } else {
+      new_plan_sp = thread->QueueThreadPlanForStepSingleInstruction(
+          true, abort_other_plans, stop_other_threads);
+    }
+  }
+  error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
 }
 
 void SBThread::StepInto(lldb::RunMode stop_other_threads) {
@@ -673,7 +679,7 @@
 
 void SBThread::StepInto(const char *target_name,
                         lldb::RunMode stop_other_threads) {
-  SBError error;
+  SBError error; // Ignored
   StepInto(target_name, LLDB_INVALID_LINE_NUMBER, error, stop_other_threads);
 }
 
@@ -691,41 +697,48 @@
         target_name ? target_name : "<NULL>",
         Thread::RunModeAsCString(stop_other_threads));
 
-  if (exe_ctx.HasThreadScope()) {
-    bool abort_other_plans = false;
+  if (!exe_ctx.HasThreadScope()) {
+    error.SetErrorString("this SBThread object is invalid");
+    return;
+  }
 
-    Thread *thread = exe_ctx.GetThreadPtr();
-    StackFrameSP frame_sp(thread->GetStackFrameAtIndex(0));
-    ThreadPlanSP new_plan_sp;
+  bool abort_other_plans = false;
 
-    if (frame_sp && frame_sp->HasDebugInformation()) {
-      SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
-      AddressRange range;
-      if (end_line == LLDB_INVALID_LINE_NUMBER)
-        range = sc.line_entry.range;
-      else {
-        if (!sc.GetAddressRangeFromHereToEndLine(end_line, range, error.ref()))
-          return;
-      }
+  Thread *thread = exe_ctx.GetThreadPtr();
+  StackFrameSP frame_sp(thread->GetStackFrameAtIndex(0));
+  ThreadPlanSP new_plan_sp;
 
-      const LazyBool step_out_avoids_code_without_debug_info =
-          eLazyBoolCalculate;
-      const LazyBool step_in_avoids_code_without_debug_info =
-          eLazyBoolCalculate;
-      new_plan_sp = thread->QueueThreadPlanForStepInRange(
-          abort_other_plans, range, sc, target_name, stop_other_threads,
-          step_in_avoids_code_without_debug_info,
-          step_out_avoids_code_without_debug_info);
-    } else {
-      new_plan_sp = thread->QueueThreadPlanForStepSingleInstruction(
-          false, abort_other_plans, stop_other_threads);
+  if (frame_sp && frame_sp->HasDebugInformation()) {
+    SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
+    AddressRange range;
+    if (end_line == LLDB_INVALID_LINE_NUMBER)
+      range = sc.line_entry.range;
+    else {
+      if (!sc.GetAddressRangeFromHereToEndLine(end_line, range, error.ref()))
+        return;
     }
 
-    error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
+    const LazyBool step_out_avoids_code_without_debug_info =
+        eLazyBoolCalculate;
+    const LazyBool step_in_avoids_code_without_debug_info =
+        eLazyBoolCalculate;
+    new_plan_sp = thread->QueueThreadPlanForStepInRange(
+        abort_other_plans, range, sc, target_name, stop_other_threads,
+        step_in_avoids_code_without_debug_info,
+        step_out_avoids_code_without_debug_info);
+  } else {
+    new_plan_sp = thread->QueueThreadPlanForStepSingleInstruction(
+        false, abort_other_plans, stop_other_threads);
   }
+  error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
 }
 
 void SBThread::StepOut() {
+  SBError error; // Ignored
+  StepOut(error);
+}
+
+void SBThread::StepOut(SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
 
   std::unique_lock<std::recursive_mutex> lock;
@@ -735,23 +748,30 @@
     log->Printf("SBThread(%p)::StepOut ()",
                 static_cast<void *>(exe_ctx.GetThreadPtr()));
 
-  if (exe_ctx.HasThreadScope()) {
-    bool abort_other_plans = false;
-    bool stop_other_threads = false;
-
-    Thread *thread = exe_ctx.GetThreadPtr();
-
-    const LazyBool avoid_no_debug = eLazyBoolCalculate;
-    ThreadPlanSP new_plan_sp(thread->QueueThreadPlanForStepOut(
-        abort_other_plans, NULL, false, stop_other_threads, eVoteYes,
-        eVoteNoOpinion, 0, avoid_no_debug));
-
-    // This returns an error, we should use it!
-    ResumeNewPlan(exe_ctx, new_plan_sp.get());
+  if (!exe_ctx.HasThreadScope()) {
+    error.SetErrorString("this SBThread object is invalid");
+    return;
   }
+
+  bool abort_other_plans = false;
+  bool stop_other_threads = false;
+
+  Thread *thread = exe_ctx.GetThreadPtr();
+
+  const LazyBool avoid_no_debug = eLazyBoolCalculate;
+  ThreadPlanSP new_plan_sp(thread->QueueThreadPlanForStepOut(
+      abort_other_plans, NULL, false, stop_other_threads, eVoteYes,
+      eVoteNoOpinion, 0, avoid_no_debug));
+
+  error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
 }
 
-void SBThread::StepOutOfFrame(lldb::SBFrame &sb_frame) {
+void SBThread::StepOutOfFrame(SBFrame &sb_frame) {
+  SBError error; // Ignored
+  StepOutOfFrame(sb_frame, error);
+}
+
+void SBThread::StepOutOfFrame(SBFrame &sb_frame, SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
 
   std::unique_lock<std::recursive_mutex> lock;
@@ -762,6 +782,7 @@
       log->Printf(
           "SBThread(%p)::StepOutOfFrame passed an invalid frame, returning.",
           static_cast<void *>(exe_ctx.GetThreadPtr()));
+    error.SetErrorString("passed invalid SBFrame object");
     return;
   }
 
@@ -774,27 +795,36 @@
                 static_cast<void *>(frame_sp.get()), frame_desc_strm.GetData());
   }
 
-  if (exe_ctx.HasThreadScope()) {
-    bool abort_other_plans = false;
-    bool stop_other_threads = false;
-    Thread *thread = exe_ctx.GetThreadPtr();
-    if (sb_frame.GetThread().GetThreadID() != thread->GetID()) {
-      log->Printf("SBThread(%p)::StepOutOfFrame passed a frame from another "
-                  "thread (0x%" PRIx64 " vrs. 0x%" PRIx64 ", returning.",
-                  static_cast<void *>(exe_ctx.GetThreadPtr()),
-                  sb_frame.GetThread().GetThreadID(), thread->GetID());
-    }
-
-    ThreadPlanSP new_plan_sp(thread->QueueThreadPlanForStepOut(
-        abort_other_plans, NULL, false, stop_other_threads, eVoteYes,
-        eVoteNoOpinion, frame_sp->GetFrameIndex()));
-
-    // This returns an error, we should use it!
-    ResumeNewPlan(exe_ctx, new_plan_sp.get());
+  if (!exe_ctx.HasThreadScope()) {
+    error.SetErrorString("this SBThread object is invalid");
+    return;
   }
+
+  bool abort_other_plans = false;
+  bool stop_other_threads = false;
+  Thread *thread = exe_ctx.GetThreadPtr();
+  if (sb_frame.GetThread().GetThreadID() != thread->GetID()) {
+    log->Printf("SBThread(%p)::StepOutOfFrame passed a frame from another "
+                "thread (0x%" PRIx64 " vrs. 0x%" PRIx64 ", returning.",
+                static_cast<void *>(exe_ctx.GetThreadPtr()),
+                sb_frame.GetThread().GetThreadID(), thread->GetID());
+    error.SetErrorString("passed a frame from another thread");
+    return;
+  }
+
+  ThreadPlanSP new_plan_sp(thread->QueueThreadPlanForStepOut(
+      abort_other_plans, NULL, false, stop_other_threads, eVoteYes,
+      eVoteNoOpinion, frame_sp->GetFrameIndex()));
+
+  error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
 }
 
 void SBThread::StepInstruction(bool step_over) {
+  SBError error; // Ignored
+  StepInstruction(step_over, error);
+}
+
+void SBThread::StepInstruction(bool step_over, SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
 
   std::unique_lock<std::recursive_mutex> lock;
@@ -804,17 +834,24 @@
     log->Printf("SBThread(%p)::StepInstruction (step_over=%i)",
                 static_cast<void *>(exe_ctx.GetThreadPtr()), step_over);
 
-  if (exe_ctx.HasThreadScope()) {
-    Thread *thread = exe_ctx.GetThreadPtr();
-    ThreadPlanSP new_plan_sp(
-        thread->QueueThreadPlanForStepSingleInstruction(step_over, true, true));
-
-    // This returns an error, we should use it!
-    ResumeNewPlan(exe_ctx, new_plan_sp.get());
+  if (!exe_ctx.HasThreadScope()) {
+    error.SetErrorString("this SBThread object is invalid");
+    return;
   }
+
+  Thread *thread = exe_ctx.GetThreadPtr();
+  ThreadPlanSP new_plan_sp(
+      thread->QueueThreadPlanForStepSingleInstruction(step_over, true, true));
+
+  error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
 }
 
 void SBThread::RunToAddress(lldb::addr_t addr) {
+  SBError error; // Ignored
+  RunToAddress(addr, error);
+}
+
+void SBThread::RunToAddress(lldb::addr_t addr, SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
 
   std::unique_lock<std::recursive_mutex> lock;
@@ -824,20 +861,22 @@
     log->Printf("SBThread(%p)::RunToAddress (addr=0x%" PRIx64 ")",
                 static_cast<void *>(exe_ctx.GetThreadPtr()), addr);
 
-  if (exe_ctx.HasThreadScope()) {
-    bool abort_other_plans = false;
-    bool stop_other_threads = true;
-
-    Address target_addr(addr);
-
-    Thread *thread = exe_ctx.GetThreadPtr();
-
-    ThreadPlanSP new_plan_sp(thread->QueueThreadPlanForRunToAddress(
-        abort_other_plans, target_addr, stop_other_threads));
-
-    // This returns an error, we should use it!
-    ResumeNewPlan(exe_ctx, new_plan_sp.get());
+  if (!exe_ctx.HasThreadScope()) {
+    error.SetErrorString("this SBThread object is invalid");
+    return;
   }
+
+  bool abort_other_plans = false;
+  bool stop_other_threads = true;
+
+  Address target_addr(addr);
+
+  Thread *thread = exe_ctx.GetThreadPtr();
+
+  ThreadPlanSP new_plan_sp(thread->QueueThreadPlanForRunToAddress(
+      abort_other_plans, target_addr, stop_other_threads));
+
+  error = ResumeNewPlan(exe_ctx, new_plan_sp.get());
 }
 
 SBError SBThread::StepOverUntil(lldb::SBFrame &sb_frame,
@@ -1082,6 +1121,11 @@
 }
 
 bool SBThread::Suspend() {
+  SBError error; // Ignored
+  return Suspend(error);
+}
+
+bool SBThread::Suspend(SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
   std::unique_lock<std::recursive_mutex> lock;
   ExecutionContext exe_ctx(m_opaque_sp.get(), lock);
@@ -1093,11 +1137,13 @@
       exe_ctx.GetThreadPtr()->SetResumeState(eStateSuspended);
       result = true;
     } else {
+      error.SetErrorString("process is running");
       if (log)
         log->Printf("SBThread(%p)::Suspend() => error: process is running",
                     static_cast<void *>(exe_ctx.GetThreadPtr()));
     }
-  }
+  } else
+    error.SetErrorString("this SBThread object is invalid");
   if (log)
     log->Printf("SBThread(%p)::Suspend() => %i",
                 static_cast<void *>(exe_ctx.GetThreadPtr()), result);
@@ -1105,6 +1151,11 @@
 }
 
 bool SBThread::Resume() {
+  SBError error; // Ignored
+  return Resume(error);
+}
+
+bool SBThread::Resume(SBError &error) {
   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_API));
   std::unique_lock<std::recursive_mutex> lock;
   ExecutionContext exe_ctx(m_opaque_sp.get(), lock);
@@ -1117,11 +1168,13 @@
       exe_ctx.GetThreadPtr()->SetResumeState(eStateRunning, override_suspend);
       result = true;
     } else {
+      error.SetErrorString("process is running");
       if (log)
         log->Printf("SBThread(%p)::Resume() => error: process is running",
                     static_cast<void *>(exe_ctx.GetThreadPtr()));
     }
-  }
+  } else
+    error.SetErrorString("this SBThread object is invalid");
   if (log)
     log->Printf("SBThread(%p)::Resume() => %i",
                 static_cast<void *>(exe_ctx.GetThreadPtr()), result);