Add data formatter for libc++ std::queue

[labath]

Summary

std::queue is just a fancy wrapper around another container, so all we
need to do is to delegate to the it.

[jingham]

This looks good.

packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libcxx/queue/Makefile

+LEVEL = ../../../../../make
+
+CXX_SOURCES := main.cpp
+
+USE_LIBCPP := 1
+include $(LEVEL)/Makefile.rules

packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libcxx/queue/TestDataFormatterLibcxxQueue.py

+"""
+Test lldb data formatter subsystem.
+"""
+
+from __future__ import print_function
+
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestDataFormatterLibcxxQueue(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    def setUp(self):
+        TestBase.setUp(self)
+        ns = 'ndk' if lldbplatformutil.target_is_android() else ''
+        self.namespace = 'std::__' + ns + '1'
+
+    def check_variable(self, name):
+        var = self.frame().FindVariable(name)
+        self.assertTrue(var.IsValid())
+
+        queue = self.namespace + '::queue'
+        self.assertTrue(queue in var.GetTypeName())
+        self.assertEqual(var.GetNumChildren(), 5)
+        for i in range(5):
+            ch = var.GetChildAtIndex(i)
+            self.assertTrue(ch.IsValid())
+            self.assertEqual(ch.GetValueAsSigned(), i+1)
+
+    @add_test_categories(["libc++"])
+    def test(self):
+        """Test that std::queue is displayed correctly"""
+        self.build()
+        lldbutil.run_to_source_breakpoint(self, '// break here',
+                lldb.SBFileSpec("main.cpp", False))
+
+        self.check_variable('q1')
+        self.check_variable('q2')

packages/Python/lldbsuite/test/functionalities/data-formatter/data-formatter-stl/libcxx/queue/main.cpp

+#include <queue>
+#include <vector>
+
+using namespace std;
+
+int main() {
+  queue<int> q1{{1,2,3,4,5}};
+  queue<int, std::vector<int>> q2{{1,2,3,4,5}};
+  int ret = q1.size() + q2.size(); // break here
+  return ret;
+}

source/Plugins/Language/CPlusPlus/CMakeLists.txt

 add_lldb_library(lldbPluginCPlusPlusLanguage PLUGIN
   BlockPointer.cpp
   CPlusPlusLanguage.cpp
   CPlusPlusNameParser.cpp
   CxxStringTypes.cpp
   LibCxx.cpp
   LibCxxAtomic.cpp
   LibCxxInitializerList.cpp
   LibCxxList.cpp
   LibCxxMap.cpp
+  LibCxxQueue.cpp
   LibCxxTuple.cpp
   LibCxxUnorderedMap.cpp
   LibCxxVector.cpp
   LibStdcpp.cpp
   LibStdcppTuple.cpp
   LibStdcppUniquePointer.cpp
 
   LINK_LIBS

source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

AddCXXSynthetic(
       ConstString("^(std::__(ndk)?1::)unordered_(multi)?(map|set)<.+> >$"),
       stl_synth_flags, true);
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::LibcxxInitializerListSyntheticFrontEndCreator,
       "libc++ std::initializer_list synthetic children",
       ConstString("^std::initializer_list<.+>(( )?&)?$"), stl_synth_flags,
       true);
+  AddCXXSynthetic(cpp_category_sp, LibcxxQueueFrontEndCreator,
+                  "libc++ std::queue synthetic children",
+                  ConstString("^std::__(ndk)?1::queue<.+>(( )?&)?$"), stl_synth_flags,
+                  true);
   AddCXXSynthetic(cpp_category_sp, LibcxxTupleFrontEndCreator,
                   "libc++ std::tuple synthetic children",
                   ConstString("^std::__(ndk)?1::tuple<.*>(( )?&)?$"), stl_synth_flags,
                   true);
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::LibcxxAtomicSyntheticFrontEndCreator,
       "libc++ std::atomic synthetic children",
AddCXXSummary(cpp_category_sp,
                 stl_summary_flags, true);
   AddCXXSummary(cpp_category_sp,
                 lldb_private::formatters::LibcxxContainerSummaryProvider,
                 "libc++ std::deque summary provider",
                 ConstString("^std::__(ndk)?1::deque<.+>(( )?&)?$"),
                 stl_summary_flags, true);
   AddCXXSummary(cpp_category_sp,
                 lldb_private::formatters::LibcxxContainerSummaryProvider,
+                "libc++ std::queue summary provider",
+                ConstString("^std::__(ndk)?1::queue<.+>(( )?&)?$"),
+                stl_summary_flags, true);
+  AddCXXSummary(cpp_category_sp,
+                lldb_private::formatters::LibcxxContainerSummaryProvider,
                 "libc++ std::set summary provider",
                 ConstString("^std::__(ndk)?1::set<.+>(( )?&)?$"),
                 stl_summary_flags, true);
   AddCXXSummary(cpp_category_sp,
                 lldb_private::formatters::LibcxxContainerSummaryProvider,
                 "libc++ std::multiset summary provider",
                 ConstString("^std::__(ndk)?1::multiset<.+>(( )?&)?$"),
                 stl_summary_flags, true);

source/Plugins/Language/CPlusPlus/LibCxx.h

 
 SyntheticChildrenFrontEnd *
 LibcxxInitializerListSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                               lldb::ValueObjectSP);
 
 SyntheticChildrenFrontEnd *LibcxxFunctionFrontEndCreator(CXXSyntheticChildren *,
                                                          lldb::ValueObjectSP);
 
+SyntheticChildrenFrontEnd *LibcxxQueueFrontEndCreator(CXXSyntheticChildren *,
+                                                      lldb::ValueObjectSP);
+
 SyntheticChildrenFrontEnd *LibcxxTupleFrontEndCreator(CXXSyntheticChildren *,
                                                       lldb::ValueObjectSP);
 
 } // namespace formatters
 } // namespace lldb_private
 
 #endif // liblldb_LibCxx_h_

source/Plugins/Language/CPlusPlus/LibCxxQueue.cpp

+//===-- LibCxxQueue.cpp -----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LibCxx.h"
+#include "lldb/DataFormatters/FormattersHelpers.h"
+
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+
+class QueueFrontEnd: public SyntheticChildrenFrontEnd {
+public:
+  QueueFrontEnd(ValueObject &valobj) : SyntheticChildrenFrontEnd(valobj) {
+    Update();
+  }
+
+  size_t GetIndexOfChildWithName(const ConstString &name) override {
+    return m_container_sp ? m_container_sp->GetIndexOfChildWithName(name)
+                          : UINT32_MAX;
+  }
+
+  bool MightHaveChildren() override { return true; }
+  bool Update() override;
+
+  size_t CalculateNumChildren() override {
+    return m_container_sp ? m_container_sp->GetNumChildren() : 0;
+  }
+
+  ValueObjectSP GetChildAtIndex(size_t idx) override {
+    return m_container_sp ? m_container_sp->GetChildAtIndex(idx, true)
+                          : nullptr;
+  }
+
+private:
+  ValueObjectSP m_container_sp;
+};
+}
+
+bool QueueFrontEnd::Update() {
+  m_container_sp.reset();
+  ValueObjectSP c_sp = m_backend.GetChildMemberWithName(ConstString("c"), true);
+  if (! c_sp)
+    return false;
+  m_container_sp = c_sp->GetSyntheticValue();
+  return false;
+}
+
+SyntheticChildrenFrontEnd *
+formatters::LibcxxQueueFrontEndCreator(CXXSyntheticChildren *,
+                                       lldb::ValueObjectSP valobj_sp) {
+  if (valobj_sp)
+    return new QueueFrontEnd(*valobj_sp);
+  return nullptr;
+}