Merge pull request #740 from medismailben/apple/stable/20200108

[lldb/Target] Add Assert StackFrame Recognizer

Author: medismailben

lldb/docs/use/formatting.rst

@@ -134,7 +134,9 @@ A complete list of currently supported format string variables is listed below:
 +---------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 | ``thread.queue``                                  | The queue name of the thread if the target OS supports dispatch queues                                                                                                                                                                                                                      |
 +---------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
-| ``thread.stop-reason``                            | A textual reason each thread stopped                                                                                                                                                                                                                                                        |
+| ``thread.stop-reason``                            | A textual reason why the thread stopped. If the thread have a recognized frame, this displays its recognized stop reason. Otherwise, gets the stop info description.                                                                                                                        |
++---------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
+| ``thread.stop-reason-raw``                        | A textual reason why the thread stopped. Always returns stop info description.                                                                                                                                                                                                              |
 +---------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
 | ``thread.return-value``                           | The return value of the latest step operation (currently only for step-out.)                                                                                                                                                                                                                |
 +---------------------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

lldb/include/lldb/Core/FormatEntity.h

@@ -61,6 +61,7 @@ class FormatEntity {
       ThreadName,
       ThreadQueue,
       ThreadStopReason,
+      ThreadStopReasonRaw,
       ThreadReturnValue,
       ThreadCompletedExpression,
       ScriptThread,

lldb/include/lldb/Target/AssertFrameRecognizer.h

@@ -0,0 +1,54 @@
+//===-- AssertFrameRecognizer.cpp -------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_AssertFrameRecognizer_h_
+#define liblldb_AssertFrameRecognizer_h_
+
+#include "lldb/Target/Process.h"
+#include "lldb/Target/StackFrameRecognizer.h"
+#include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/FileSpec.h"
+
+#include <tuple>
+
+namespace lldb_private {
+
+/// Registers the assert stack frame recognizer.
+///
+/// \param[in] process
+///    The process that is currently asserting. This will give us information on
+///    the target and the platform.
+void RegisterAssertFrameRecognizer(Process *process);
+
+/// \class AssertRecognizedStackFrame
+///
+/// Holds the stack frame where the assert is called from.
+class AssertRecognizedStackFrame : public RecognizedStackFrame {
+public:
+  AssertRecognizedStackFrame(lldb::StackFrameSP most_relevant_frame_sp);
+  lldb::StackFrameSP GetMostRelevantFrame() override;
+
+private:
+  lldb::StackFrameSP m_most_relevant_frame;
+};
+
+/// \class AssertFrameRecognizer
+///
+/// When a thread stops, it checks depending on the platform if the top frame is
+/// an abort stack frame. If so, it looks for an assert stack frame in the upper
+/// frames and set it as the most relavant frame when found.
+class AssertFrameRecognizer : public StackFrameRecognizer {
+public:
+  std::string GetName() override { return "Assert StackFrame Recognizer"; }
+  lldb::RecognizedStackFrameSP
+  RecognizeFrame(lldb::StackFrameSP frame_sp) override;
+};
+
+} // namespace lldb_private
+
+#endif // liblldb_AssertFrameRecognizer_h_

lldb/include/lldb/Target/StackFrameRecognizer.h

@@ -12,6 +12,7 @@
 #include "lldb/Core/ValueObject.h"
 #include "lldb/Core/ValueObjectList.h"
 #include "lldb/Symbol/VariableList.h"
+#include "lldb/Target/StopInfo.h"
 #include "lldb/Utility/StructuredData.h"
 #include "lldb/lldb-private-forward.h"
 #include "lldb/lldb-public.h"
@@ -33,10 +34,14 @@ class RecognizedStackFrame
   virtual lldb::ValueObjectSP GetExceptionObject() {
     return lldb::ValueObjectSP();
   }
+  virtual lldb::StackFrameSP GetMostRelevantFrame() { return nullptr; };
   virtual ~RecognizedStackFrame(){};
 
+  std::string GetStopDescription() { return m_stop_desc; }
+
 protected:
   lldb::ValueObjectListSP m_arguments;
+  std::string m_stop_desc;
 };
 
 /// \class StackFrameRecognizer

lldb/include/lldb/Target/Thread.h

@@ -216,6 +216,12 @@ class Thread : public std::enable_shared_from_this<Thread>,
 
   virtual void RefreshStateAfterStop() = 0;
 
+  void SelectMostRelevantFrame();
+
+  std::string GetStopDescription();
+
+  std::string GetStopDescriptionRaw();
+
   void WillStop();
 
   bool ShouldStop(Event *event_ptr);

lldb/packages/Python/lldbsuite/test/functionalities/inferior-assert/TestInferiorAssert.py

@@ -107,16 +107,22 @@ def check_stop_reason(self):
         if matched:
             # On android until API-16 the abort() call ended in a sigsegv
             # instead of in a sigabrt
-            stop_reason = 'stop reason = signal SIGSEGV'
+            stop_reason = 'signal SIGSEGV'
         else:
-            stop_reason = 'stop reason = signal SIGABRT'
+            stop_reason = 'signal SIGABRT'
+
+        target = self.dbg.GetTargetAtIndex(0)
+        process = target.GetProcess()
+        thread = lldbutil.get_stopped_thread(process, lldb.eStopReasonSignal)
+
+        pattern = "stop reason = (" + stop_reason + "|hit program assert)"
 
         # The stop reason of the thread should be an abort signal or exception.
         self.expect("thread list", STOPPED_DUE_TO_ASSERT,
-                    substrs=['stopped',
-                             stop_reason])
+                    patterns=[pattern],
+                    substrs=['stopped'])
 
-        return stop_reason
+        return pattern
 
     def setUp(self):
         # Call super's setUp().
@@ -134,12 +140,13 @@ def inferior_asserting(self):
 
         # And it should report a backtrace that includes the assert site.
         self.expect("thread backtrace all",
-                    substrs=[stop_reason, 'main', 'argc', 'argv'])
+                    patterns=[stop_reason],
+                    substrs=['main', 'argc', 'argv'])
 
         # And it should report the correct line number.
         self.expect("thread backtrace all",
-                    substrs=[stop_reason,
-                             'main.c:%d' % self.line])
+                    patterns=[stop_reason],
+                    substrs=['main.c:%d' % self.line])
 
     def inferior_asserting_python(self):
         """Inferior asserts upon launching; lldb should catch the event and stop."""
@@ -173,6 +180,10 @@ def inferior_asserting_registers(self):
         self.runCmd("run", RUN_SUCCEEDED)
         self.check_stop_reason()
 
+        # change current frame to frame 0, since recognizer might have selected
+        # different frame.
+        self.runCmd("frame select 0", RUN_SUCCEEDED)
+
         # lldb should be able to read from registers from the inferior after
         # asserting.
         lldbplatformutil.check_first_register_readable(self)
@@ -311,5 +322,5 @@ def inferior_asserting_step(self):
 
         # And it should report the correct line number.
         self.expect("thread backtrace all",
-                    substrs=[stop_reason,
-                             'main.c:%d' % self.line])
+                    patterns=[stop_reason],
+                    substrs=['main.c:%d' % self.line])

lldb/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py

@@ -25,8 +25,8 @@ def test_objc_exceptions_at_throw(self):
         launch_info = lldb.SBLaunchInfo(["a.out", "0"])
         lldbutil.run_to_name_breakpoint(self, "objc_exception_throw", launch_info=launch_info)
 
-        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
-                    substrs=['stopped', 'stop reason = breakpoint'])
+        self.expect("thread list",
+            substrs=['stopped', 'stop reason = hit Objective-C exception'])
 
         self.expect('thread exception', substrs=[
                 '(NSException *) exception = ',

lldb/source/API/SBThread.cpp

@@ -325,8 +325,11 @@ size_t SBThread::GetStopDescription(char *dst, size_t dst_len) {
 
       StopInfoSP stop_info_sp = exe_ctx.GetThreadPtr()->GetStopInfo();
       if (stop_info_sp) {
-        const char *stop_desc = stop_info_sp->GetDescription();
-        if (stop_desc) {
+        std::string thread_stop_desc =
+            exe_ctx.GetThreadPtr()->GetStopDescription();
+        const char *stop_desc = thread_stop_desc.c_str();
+
+        if (stop_desc[0] != '\0') {
           if (dst)
             return ::snprintf(dst, dst_len, "%s", stop_desc);
           else {

lldb/source/Core/FormatEntity.cpp

@@ -166,6 +166,7 @@ static FormatEntity::Entry::Definition g_thread_child_entries[] = {
     ENTRY("queue", ThreadQueue),
     ENTRY("name", ThreadName),
     ENTRY("stop-reason", ThreadStopReason),
+    ENTRY("stop-reason-raw", ThreadStopReasonRaw),
     ENTRY("return-value", ThreadReturnValue),
     ENTRY("completed-expression", ThreadCompletedExpression),
 };
@@ -328,6 +329,7 @@ const char *FormatEntity::Entry::TypeToCString(Type t) {
     ENUM_TO_CSTR(ThreadName);
     ENUM_TO_CSTR(ThreadQueue);
     ENUM_TO_CSTR(ThreadStopReason);
+    ENUM_TO_CSTR(ThreadStopReasonRaw);
     ENUM_TO_CSTR(ThreadReturnValue);
     ENUM_TO_CSTR(ThreadCompletedExpression);
     ENUM_TO_CSTR(ScriptThread);
@@ -1273,15 +1275,23 @@ bool FormatEntity::Format(const Entry &entry, Stream &s,
 
   case Entry::Type::ThreadStopReason:
     if (exe_ctx) {
-      Thread *thread = exe_ctx->GetThreadPtr();
-      if (thread) {
-        StopInfoSP stop_info_sp = thread->GetStopInfo();
-        if (stop_info_sp && stop_info_sp->IsValid()) {
-          const char *cstr = stop_info_sp->GetDescription();
-          if (cstr && cstr[0]) {
-            s.PutCString(cstr);
-            return true;
-          }
+      if (Thread *thread = exe_ctx->GetThreadPtr()) {
+        std::string stop_description = thread->GetStopDescription();
+        if (!stop_description.empty()) {
+          s.PutCString(stop_description);
+          return true;
+        }
+      }
+    }
+    return false;
+
+  case Entry::Type::ThreadStopReasonRaw:
+    if (exe_ctx) {
+      if (Thread *thread = exe_ctx->GetThreadPtr()) {
+        std::string stop_description = thread->GetStopDescriptionRaw();
+        if (!stop_description.empty()) {
+          s.PutCString(stop_description);
+          return true;
         }
       }
     }

lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp

@@ -2698,6 +2698,8 @@ class ObjCExceptionRecognizedStackFrame : public RecognizedStackFrame {
 
     m_arguments = ValueObjectListSP(new ValueObjectList());
     m_arguments->Append(exception);
+
+    m_stop_desc = "hit Objective-C exception";
   }
 
   ValueObjectSP exception;