Add formatter for libc++ std::unique_ptr

[shafik]

Summary

This adds a formatter for libc++ std::unique_ptr. We currently already have formatters for std::shared_ptr and std::weak_ptr.

I also refactored GetValueOfCompressedPair(...) out of LibCxxList.cpp since I need the same functionality and it made sense to share it.

[vsk]

Awesome :)

lldb/include/lldb/DataFormatters/FormattersHelpers.h

59

Mind adding ‘libcxx’ somewhere in the function name, to avoid confusion?

lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

618

Does this need to match for rvalue refs, like ‘unique_ptr<blah> &&’?

728

Can we share the regex definition?

[shafik]

Addressing comments on naming and not duplicating the regex

lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

618

I tried this out and apparently not.

[vsk]

LGTM with some added test coverage. Jim?

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unique_ptr/main.cpp

10

Could you add test coverage for '&' and '&&', like

const std::unique_ptr<std::string> &up_str_ref = up_str;
std::unique_ptr<int> &&up_int_rvref = std::move(up_int);

[shafik]

Adding addition tests for references

lldb/include/lldb/DataFormatters/FormattersHelpers.h

void AddFilter(TypeCategoryImpl::SharedPointer category_sp,
                std::vector<std::string> children, const char *description,
                ConstString type_name, ScriptedSyntheticChildren::Flags flags,
                bool regex = false);
 
 size_t ExtractIndexFromString(const char *item_name);
 
 lldb::addr_t GetArrayAddressOrPointerValue(ValueObject &valobj);
 
+lldb::ValueObjectSP GetValueOfCompressedPair(ValueObject &pair);
+
 time_t GetOSXEpoch();
 
 struct InferiorSizedWord {
 
   InferiorSizedWord(const InferiorSizedWord &word) : ptr_size(word.ptr_size) {
     if (ptr_size == 4)
       thirty_two = word.thirty_two;
     else

lldb/source/DataFormatters/FormattersHelpers.cpp

lldb_private::formatters::GetArrayAddressOrPointerValue(ValueObject &valobj) {
 
   if (valobj.IsPointerType())
     data_addr = valobj.GetValueAsUnsigned(0);
   else if (valobj.IsArrayType())
     data_addr = valobj.GetAddressOf();
 
   return data_addr;
 }
+
+lldb::ValueObjectSP
+lldb_private::formatters::GetValueOfCompressedPair(ValueObject &pair) {
+  ValueObjectSP value =
+      pair.GetChildMemberWithName(ConstString("__value_"), true);
+  if (!value) {
+    // pre-r300140 member name
+    value = pair.GetChildMemberWithName(ConstString("__first_"), true);
+  }
+  return value;
+}

lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

static void LoadLibCxxFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEndCreator,
       "shared_ptr synthetic children",
       ConstString("^(std::__[[:alnum:]]+::)shared_ptr<.+>(( )?&)?$"),
       stl_synth_flags, true);
   AddCXXSynthetic(
       cpp_category_sp,
+      lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEndCreator,
+      "unique_ptr synthetic children",
+      ConstString("^(std::__[[:alnum:]]+::)unique_ptr<.+>(( )?&)?$"),
+      stl_synth_flags, true);
+
+  AddCXXSynthetic(
+      cpp_category_sp,
       lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEndCreator,
       "weak_ptr synthetic children",
       ConstString("^(std::__[[:alnum:]]+::)weak_ptr<.+>(( )?&)?$"),
       stl_synth_flags, true);
   AddCXXSummary(cpp_category_sp,
                 lldb_private::formatters::LibcxxFunctionSummaryProvider,
                 "libc++ std::function summary provider",
                 ConstString("^std::__[[:alnum:]]+::function<.+>$"),
AddCXXSummary(cpp_category_sp,
                 "libc++ std::shared_ptr summary provider",
                 ConstString("^std::__[[:alnum:]]+::shared_ptr<.+>(( )?&)?$"),
                 stl_summary_flags, true);
   AddCXXSummary(cpp_category_sp,
                 lldb_private::formatters::LibcxxSmartPointerSummaryProvider,
                 "libc++ std::weak_ptr summary provider",
                 ConstString("^std::__[[:alnum:]]+::weak_ptr<.+>(( )?&)?$"),
                 stl_summary_flags, true);
+  AddCXXSummary(cpp_category_sp,
+                lldb_private::formatters::LibcxxUniquePointerSummaryProvider,
+                "libc++ std::unique_ptr summary provider",
+                ConstString("^std::__[[:alnum:]]+::unique_ptr<.+>(( )?&)?$"),
+                stl_summary_flags, true);
 
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::LibCxxVectorIteratorSyntheticFrontEndCreator,
       "std::vector iterator synthetic children",
       ConstString("^std::__[[:alnum:]]+::__wrap_iter<.+>$"), stl_synth_flags,
       true);
 

lldb/source/Plugins/Language/CPlusPlus/LibCxx.h

bool LibcxxOptionalSummaryProvider(
     ValueObject &valobj, Stream &stream,
     const TypeSummaryOptions &options); // libc++ std::optional<>
 
 bool LibcxxSmartPointerSummaryProvider(
     ValueObject &valobj, Stream &stream,
     const TypeSummaryOptions
         &options); // libc++ std::shared_ptr<> and std::weak_ptr<>
 
+// libc++ std::unique_ptr<>
+bool LibcxxUniquePointerSummaryProvider(ValueObject &valobj, Stream &stream,
+                                        const TypeSummaryOptions &options);
+
 bool LibcxxFunctionSummaryProvider(
     ValueObject &valobj, Stream &stream,
     const TypeSummaryOptions &options); // libc++ std::function<>
 
 SyntheticChildrenFrontEnd *
 LibcxxVectorBoolSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                          lldb::ValueObjectSP);
 

 private:
   ValueObject *m_cntrl;
   lldb::ValueObjectSP m_count_sp;
   lldb::ValueObjectSP m_weak_count_sp;
   uint8_t m_ptr_size;
   lldb::ByteOrder m_byte_order;
 };
 
+class LibcxxUniquePtrSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
+public:
+  LibcxxUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
+
+  size_t CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
+
+  bool Update() override;
+
+  bool MightHaveChildren() override;
+
+  size_t GetIndexOfChildWithName(ConstString name) override;
+
+  ~LibcxxUniquePtrSyntheticFrontEnd() override;
+
+private:
+  lldb::ValueObjectSP m_compressed_pair_sp;
+};
+
 SyntheticChildrenFrontEnd *
 LibcxxBitsetSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                      lldb::ValueObjectSP);
 
 SyntheticChildrenFrontEnd *
 LibcxxSharedPtrSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                         lldb::ValueObjectSP);
 
 SyntheticChildrenFrontEnd *
+LibcxxUniquePtrSyntheticFrontEndCreator(CXXSyntheticChildren *,
+                                        lldb::ValueObjectSP);
+
+SyntheticChildrenFrontEnd *
 LibcxxStdVectorSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                         lldb::ValueObjectSP);
 
 SyntheticChildrenFrontEnd *
 LibcxxStdListSyntheticFrontEndCreator(CXXSyntheticChildren *,
                                       lldb::ValueObjectSP);
 
 SyntheticChildrenFrontEnd *

lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp

if (count_sp)
     stream.Printf(" strong=%" PRIu64, 1 + count_sp->GetValueAsUnsigned(0));
 
   if (weakcount_sp)
     stream.Printf(" weak=%" PRIu64, 1 + weakcount_sp->GetValueAsUnsigned(0));
 
   return true;
 }
 
+bool lldb_private::formatters::LibcxxUniquePointerSummaryProvider(
+    ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
+  ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
+  if (!valobj_sp)
+    return false;
+
+  ValueObjectSP ptr_sp(
+      valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true));
+  if (!ptr_sp)
+    return false;
+
+  ptr_sp = GetValueOfCompressedPair(*ptr_sp);
+  if (!ptr_sp)
+    return false;
+
+  if (ptr_sp->GetValueAsUnsigned(0) == 0) {
+    stream.Printf("nullptr");
+    return true;
+  } else {
+    bool print_pointee = false;
+    Status error;
+    ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
+    if (pointee_sp && error.Success()) {
+      if (pointee_sp->DumpPrintableRepresentation(
+              stream, ValueObject::eValueObjectRepresentationStyleSummary,
+              lldb::eFormatInvalid,
+              ValueObject::PrintableRepresentationSpecialCases::eDisable,
+              false))
+        print_pointee = true;
+    }
+    if (!print_pointee)
+      stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
+  }
+
+  return true;
+}
+
 /*
  (lldb) fr var ibeg --raw --ptr-depth 1
  (std::__1::__map_iterator<std::__1::__tree_iterator<std::__1::pair<int,
  std::__1::basic_string<char, std::__1::char_traits<char>,
  std::__1::allocator<char> > >, std::__1::__tree_node<std::__1::pair<int,
  std::__1::basic_string<char, std::__1::char_traits<char>,
  std::__1::allocator<char> > >, void *> *, long> >) ibeg = {
  __i_ = {

 
 SyntheticChildrenFrontEnd *
 lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEndCreator(
     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
   return (valobj_sp ? new LibcxxSharedPtrSyntheticFrontEnd(valobj_sp)
                     : nullptr);
 }
 
+lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
+    LibcxxUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
+    : SyntheticChildrenFrontEnd(*valobj_sp), m_compressed_pair_sp() {
+  if (valobj_sp)
+    Update();
+}
+
+lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
+    ~LibcxxUniquePtrSyntheticFrontEnd() = default;
+
+SyntheticChildrenFrontEnd *
+lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEndCreator(
+    CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
+  return (valobj_sp ? new LibcxxUniquePtrSyntheticFrontEnd(valobj_sp)
+                    : nullptr);
+}
+
+size_t lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
+    CalculateNumChildren() {
+  return (m_compressed_pair_sp ? 1 : 0);
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::GetChildAtIndex(
+    size_t idx) {
+  if (!m_compressed_pair_sp)
+    return lldb::ValueObjectSP();
+
+  if (idx != 0)
+    return lldb::ValueObjectSP();
+
+  return m_compressed_pair_sp;
+}
+
+bool lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::Update() {
+  ValueObjectSP valobj_sp = m_backend.GetSP();
+  if (!valobj_sp)
+    return false;
+
+  ValueObjectSP ptr_sp(
+      valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true));
+  if (!ptr_sp)
+    return false;
+
+  m_compressed_pair_sp = GetValueOfCompressedPair(*ptr_sp);
+
+  return false;
+}
+
+bool lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
+    MightHaveChildren() {
+  return true;
+}
+
+size_t lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
+    GetIndexOfChildWithName(ConstString name) {
+  if (name == "__value_")
+    return 0;
+  return UINT32_MAX;
+}
+
 bool lldb_private::formatters::LibcxxContainerSummaryProvider(
     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
   if (valobj.IsPointerType()) {
     uint64_t value = valobj.GetValueAsUnsigned(0);
     if (!value)
       return false;
     stream.Printf("0x%016" PRIx64 " ", value);
   }

lldb/source/Plugins/Language/CPlusPlus/LibCxxList.cpp

ValueObjectSP ForwardListFrontEnd::GetChildAtIndex(size_t idx) {
   if (error.Fail())
     return nullptr;
 
   return CreateValueObjectFromData(llvm::formatv("[{0}]", idx).str(), data,
                                    m_backend.GetExecutionContextRef(),
                                    m_element_type);
 }
 
-static ValueObjectSP GetValueOfCompressedPair(ValueObject &pair) {
-  ValueObjectSP value = pair.GetChildMemberWithName(ConstString("__value_"), true);
-  if (! value) {
-    // pre-r300140 member name
-    value = pair.GetChildMemberWithName(ConstString("__first_"), true);
-  }
-  return value;
-}
-
 bool ForwardListFrontEnd::Update() {
   AbstractListFrontEnd::Update();
 
   Status err;
   ValueObjectSP backend_addr(m_backend.AddressOf(err));
   if (err.Fail() || !backend_addr)
     return false;
 

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unique_ptr/Makefile

+CXX_SOURCES := main.cpp
+
+USE_LIBCPP := 1
+
+CXXFLAGS_EXTRAS := -std=c++14
+include Makefile.rules

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unique_ptr/TestDataFormatterLibcxxUniquePtr.py

+"""
+Test lldb data formatter for libc++ std::unique_ptr.
+"""
+
+
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class LibcxUniquePtrDataFormatterTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @add_test_categories(["libc++"])
+    def test_with_run_command(self):
+        """Test that that file and class static variables display correctly."""
+        self.build()
+
+        (self.target, self.process, _, bkpt) = lldbutil.run_to_source_breakpoint(self, '// break here',
+                lldb.SBFileSpec("main.cpp", False))
+
+        self.expect("frame variable up_empty",
+                substrs=['(std::unique_ptr<int, std::default_delete<int> >) up_empty = nullptr {',
+                               '__value_ = ',
+                               '}'])
+
+        self.expect("frame variable up_int",
+                substrs=['(std::unique_ptr<int, std::default_delete<int> >) up_int = 10 {',
+                               '__value_ = ',
+                               '}'])
+
+        self.expect("frame variable up_str",
+                substrs=['up_str = "hello" {',
+                               '__value_ = ',
+                               '}'])

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/unique_ptr/main.cpp

+#include <cstdio>
+#include <string>
+#include <memory>
+
+int main()
+{
+  std::unique_ptr<int> up_empty;
+  std::unique_ptr<int> up_int = std::make_unique<int>(10);
+  std::unique_ptr<std::string> up_str = std::make_unique<std::string>("hello");
+
+  return 0; // break here
+}