//===-- LibCxx.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 // //===----------------------------------------------------------------------===// #include "LibCxx.h" #include "llvm/ADT/ScopeExit.h" #include "lldb/Core/Debugger.h" #include "lldb/Core/FormatEntity.h" #include "lldb/Core/ValueObject.h" #include "lldb/Core/ValueObjectConstResult.h" #include "lldb/DataFormatters/FormattersHelpers.h" #include "lldb/DataFormatters/StringPrinter.h" #include "lldb/DataFormatters/TypeSummary.h" #include "lldb/DataFormatters/VectorIterator.h" #include "lldb/Symbol/ClangASTContext.h" #include "lldb/Target/ProcessStructReader.h" #include "lldb/Target/SectionLoadList.h" #include "lldb/Target/Target.h" #include "lldb/Utility/DataBufferHeap.h" #include "lldb/Utility/Endian.h" #include "lldb/Utility/Status.h" #include "lldb/Utility/Stream.h" #include "Plugins/LanguageRuntime/CPlusPlus/CPPLanguageRuntime.h" using namespace lldb; using namespace lldb_private; using namespace lldb_private::formatters; bool lldb_private::formatters::LibcxxOptionalSummaryProvider( ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) { ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue()); if (!valobj_sp) return false; // An optional either contains a value or not, the member __engaged_ is // a bool flag, it is true if the optional has a value and false otherwise. ValueObjectSP engaged_sp( valobj_sp->GetChildMemberWithName(ConstString("__engaged_"), true)); if (!engaged_sp) return false; llvm::StringRef engaged_as_cstring( engaged_sp->GetValueAsUnsigned(0) == 1 ? "true" : "false"); stream.Printf(" Has Value=%s ", engaged_as_cstring.data()); return true; } bool lldb_private::formatters::LibcxxFunctionSummaryProvider( ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) { ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue()); if (!valobj_sp) return false; ExecutionContext exe_ctx(valobj_sp->GetExecutionContextRef()); Process *process = exe_ctx.GetProcessPtr(); if (process == nullptr) return false; CPPLanguageRuntime *cpp_runtime = CPPLanguageRuntime::Get(*process); if (!cpp_runtime) return false; CPPLanguageRuntime::LibCppStdFunctionCallableInfo callable_info = cpp_runtime->FindLibCppStdFunctionCallableInfo(valobj_sp); switch (callable_info.callable_case) { case CPPLanguageRuntime::LibCppStdFunctionCallableCase::Invalid: stream.Printf(" __f_ = %" PRIu64, callable_info.member__f_pointer_value); return false; break; case CPPLanguageRuntime::LibCppStdFunctionCallableCase::Lambda: stream.Printf( " Lambda in File %s at Line %u", callable_info.callable_line_entry.file.GetFilename().GetCString(), callable_info.callable_line_entry.line); break; case CPPLanguageRuntime::LibCppStdFunctionCallableCase::CallableObject: stream.Printf( " Function in File %s at Line %u", callable_info.callable_line_entry.file.GetFilename().GetCString(), callable_info.callable_line_entry.line); break; case CPPLanguageRuntime::LibCppStdFunctionCallableCase::FreeOrMemberFunction: stream.Printf(" Function = %s ", callable_info.callable_symbol.GetName().GetCString()); break; } return true; } bool lldb_private::formatters::LibcxxSmartPointerSummaryProvider( 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)); ValueObjectSP count_sp(valobj_sp->GetChildAtNamePath( {ConstString("__cntrl_"), ConstString("__shared_owners_")})); ValueObjectSP weakcount_sp(valobj_sp->GetChildAtNamePath( {ConstString("__cntrl_"), ConstString("__shared_weak_owners_")})); 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)); } 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; } /* (lldb) fr var ibeg --raw --ptr-depth 1 (std::__1::__map_iterator, std::__1::allocator > >, std::__1::__tree_node, std::__1::allocator > >, void *> *, long> >) ibeg = { __i_ = { __ptr_ = 0x0000000100103870 { std::__1::__tree_node_base = { std::__1::__tree_end_node *> = { __left_ = 0x0000000000000000 } __right_ = 0x0000000000000000 __parent_ = 0x00000001001038b0 __is_black_ = true } __value_ = { first = 0 second = { std::string } */ lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd:: LibCxxMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp) : SyntheticChildrenFrontEnd(*valobj_sp), m_pair_ptr(), m_pair_sp() { if (valobj_sp) Update(); } bool lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::Update() { m_pair_sp.reset(); m_pair_ptr = nullptr; ValueObjectSP valobj_sp = m_backend.GetSP(); if (!valobj_sp) return false; TargetSP target_sp(valobj_sp->GetTargetSP()); if (!target_sp) return false; if (!valobj_sp) return false; static ConstString g___i_("__i_"); // this must be a ValueObject* because it is a child of the ValueObject we // are producing children for it if were a ValueObjectSP, we would end up // with a loop (iterator -> synthetic -> child -> parent == iterator) and // that would in turn leak memory by never allowing the ValueObjects to die // and free their memory m_pair_ptr = valobj_sp ->GetValueForExpressionPath( ".__i_.__ptr_->__value_", nullptr, nullptr, ValueObject::GetValueForExpressionPathOptions() .DontCheckDotVsArrowSyntax() .SetSyntheticChildrenTraversal( ValueObject::GetValueForExpressionPathOptions:: SyntheticChildrenTraversal::None), nullptr) .get(); if (!m_pair_ptr) { m_pair_ptr = valobj_sp ->GetValueForExpressionPath( ".__i_.__ptr_", nullptr, nullptr, ValueObject::GetValueForExpressionPathOptions() .DontCheckDotVsArrowSyntax() .SetSyntheticChildrenTraversal( ValueObject::GetValueForExpressionPathOptions:: SyntheticChildrenTraversal::None), nullptr) .get(); if (m_pair_ptr) { auto __i_(valobj_sp->GetChildMemberWithName(g___i_, true)); if (!__i_) { m_pair_ptr = nullptr; return false; } CompilerType pair_type( __i_->GetCompilerType().GetTypeTemplateArgument(0)); std::string name; uint64_t bit_offset_ptr; uint32_t bitfield_bit_size_ptr; bool is_bitfield_ptr; pair_type = pair_type.GetFieldAtIndex( 0, name, &bit_offset_ptr, &bitfield_bit_size_ptr, &is_bitfield_ptr); if (!pair_type) { m_pair_ptr = nullptr; return false; } auto addr(m_pair_ptr->GetValueAsUnsigned(LLDB_INVALID_ADDRESS)); m_pair_ptr = nullptr; if (addr && addr != LLDB_INVALID_ADDRESS) { ClangASTContext *ast_ctx = llvm::dyn_cast_or_null(pair_type.GetTypeSystem()); if (!ast_ctx) return false; CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier( ConstString(), {{"ptr0", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()}, {"ptr1", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()}, {"ptr2", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()}, {"cw", ast_ctx->GetBasicType(lldb::eBasicTypeBool)}, {"payload", pair_type}}); llvm::Optional size = tree_node_type.GetByteSize(nullptr); if (!size) return false; DataBufferSP buffer_sp(new DataBufferHeap(*size, 0)); ProcessSP process_sp(target_sp->GetProcessSP()); Status error; process_sp->ReadMemory(addr, buffer_sp->GetBytes(), buffer_sp->GetByteSize(), error); if (error.Fail()) return false; DataExtractor extractor(buffer_sp, process_sp->GetByteOrder(), process_sp->GetAddressByteSize()); auto pair_sp = CreateValueObjectFromData( "pair", extractor, valobj_sp->GetExecutionContextRef(), tree_node_type); if (pair_sp) m_pair_sp = pair_sp->GetChildAtIndex(4, true); } } } return false; } size_t lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd:: CalculateNumChildren() { return 2; } lldb::ValueObjectSP lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::GetChildAtIndex( size_t idx) { if (m_pair_ptr) return m_pair_ptr->GetChildAtIndex(idx, true); if (m_pair_sp) return m_pair_sp->GetChildAtIndex(idx, true); return lldb::ValueObjectSP(); } bool lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd:: MightHaveChildren() { return true; } size_t lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd:: GetIndexOfChildWithName(ConstString name) { if (name == "first") return 0; if (name == "second") return 1; return UINT32_MAX; } lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd:: ~LibCxxMapIteratorSyntheticFrontEnd() { // this will be deleted when its parent dies (since it's a child object) // delete m_pair_ptr; } SyntheticChildrenFrontEnd * lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEndCreator( CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) { return (valobj_sp ? new LibCxxMapIteratorSyntheticFrontEnd(valobj_sp) : nullptr); } /* (lldb) fr var ibeg --raw --ptr-depth 1 -T (std::__1::__wrap_iter) ibeg = { (std::__1::__wrap_iter::iterator_type) __i = 0x00000001001037a0 { (int) *__i = 1 } } */ SyntheticChildrenFrontEnd * lldb_private::formatters::LibCxxVectorIteratorSyntheticFrontEndCreator( CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) { static ConstString g_item_name; if (!g_item_name) g_item_name.SetCString("__i"); return (valobj_sp ? new VectorIteratorSyntheticFrontEnd(valobj_sp, g_item_name) : nullptr); } lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd:: LibcxxSharedPtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp) : SyntheticChildrenFrontEnd(*valobj_sp), m_cntrl(nullptr), m_count_sp(), m_weak_count_sp(), m_ptr_size(0), m_byte_order(lldb::eByteOrderInvalid) { if (valobj_sp) Update(); } size_t lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd:: CalculateNumChildren() { return (m_cntrl ? 1 : 0); } lldb::ValueObjectSP lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::GetChildAtIndex( size_t idx) { if (!m_cntrl) return lldb::ValueObjectSP(); ValueObjectSP valobj_sp = m_backend.GetSP(); if (!valobj_sp) return lldb::ValueObjectSP(); if (idx == 0) return valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true); if (idx > 2) return lldb::ValueObjectSP(); if (idx == 1) { if (!m_count_sp) { ValueObjectSP shared_owners_sp(m_cntrl->GetChildMemberWithName( ConstString("__shared_owners_"), true)); if (!shared_owners_sp) return lldb::ValueObjectSP(); uint64_t count = 1 + shared_owners_sp->GetValueAsUnsigned(0); DataExtractor data(&count, 8, m_byte_order, m_ptr_size); m_count_sp = CreateValueObjectFromData( "count", data, valobj_sp->GetExecutionContextRef(), shared_owners_sp->GetCompilerType()); } return m_count_sp; } else /* if (idx == 2) */ { if (!m_weak_count_sp) { ValueObjectSP shared_weak_owners_sp(m_cntrl->GetChildMemberWithName( ConstString("__shared_weak_owners_"), true)); if (!shared_weak_owners_sp) return lldb::ValueObjectSP(); uint64_t count = 1 + shared_weak_owners_sp->GetValueAsUnsigned(0); DataExtractor data(&count, 8, m_byte_order, m_ptr_size); m_weak_count_sp = CreateValueObjectFromData( "count", data, valobj_sp->GetExecutionContextRef(), shared_weak_owners_sp->GetCompilerType()); } return m_weak_count_sp; } } bool lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::Update() { m_count_sp.reset(); m_weak_count_sp.reset(); m_cntrl = nullptr; ValueObjectSP valobj_sp = m_backend.GetSP(); if (!valobj_sp) return false; TargetSP target_sp(valobj_sp->GetTargetSP()); if (!target_sp) return false; m_byte_order = target_sp->GetArchitecture().GetByteOrder(); m_ptr_size = target_sp->GetArchitecture().GetAddressByteSize(); lldb::ValueObjectSP cntrl_sp( valobj_sp->GetChildMemberWithName(ConstString("__cntrl_"), true)); m_cntrl = cntrl_sp.get(); // need to store the raw pointer to avoid a circular // dependency return false; } bool lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd:: MightHaveChildren() { return true; } size_t lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd:: GetIndexOfChildWithName(ConstString name) { if (name == "__ptr_") return 0; if (name == "count") return 1; if (name == "weak_count") return 2; return UINT32_MAX; } lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd:: ~LibcxxSharedPtrSyntheticFrontEnd() = default; SyntheticChildrenFrontEnd * lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEndCreator( CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) { return (valobj_sp ? new LibcxxSharedPtrSyntheticFrontEnd(valobj_sp) : nullptr); } 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); } return FormatEntity::FormatStringRef("size=${svar%#}", stream, nullptr, nullptr, nullptr, &valobj, false, false); } // the field layout in a libc++ string (cap, side, data or data, size, cap) enum LibcxxStringLayoutMode { eLibcxxStringLayoutModeCSD = 0, eLibcxxStringLayoutModeDSC = 1, eLibcxxStringLayoutModeInvalid = 0xffff }; // this function abstracts away the layout and mode details of a libc++ string // and returns the address of the data and the size ready for callers to // consume static bool ExtractLibcxxStringInfo(ValueObject &valobj, ValueObjectSP &location_sp, uint64_t &size) { ValueObjectSP D(valobj.GetChildAtIndexPath({0, 0, 0, 0})); if (!D) return false; ValueObjectSP layout_decider( D->GetChildAtIndexPath(llvm::ArrayRef({0, 0}))); // this child should exist if (!layout_decider) return false; ConstString g_data_name("__data_"); ConstString g_size_name("__size_"); bool short_mode = false; // this means the string is in short-mode and the // data is stored inline LibcxxStringLayoutMode layout = (layout_decider->GetName() == g_data_name) ? eLibcxxStringLayoutModeDSC : eLibcxxStringLayoutModeCSD; uint64_t size_mode_value = 0; if (layout == eLibcxxStringLayoutModeDSC) { ValueObjectSP size_mode(D->GetChildAtIndexPath({1, 1, 0})); if (!size_mode) return false; if (size_mode->GetName() != g_size_name) { // we are hitting the padding structure, move along size_mode = D->GetChildAtIndexPath({1, 1, 1}); if (!size_mode) return false; } size_mode_value = (size_mode->GetValueAsUnsigned(0)); short_mode = ((size_mode_value & 0x80) == 0); } else { ValueObjectSP size_mode(D->GetChildAtIndexPath({1, 0, 0})); if (!size_mode) return false; size_mode_value = (size_mode->GetValueAsUnsigned(0)); short_mode = ((size_mode_value & 1) == 0); } if (short_mode) { ValueObjectSP s(D->GetChildAtIndex(1, true)); if (!s) return false; location_sp = s->GetChildAtIndex( (layout == eLibcxxStringLayoutModeDSC) ? 0 : 1, true); size = (layout == eLibcxxStringLayoutModeDSC) ? size_mode_value : ((size_mode_value >> 1) % 256); return (location_sp.get() != nullptr); } else { ValueObjectSP l(D->GetChildAtIndex(0, true)); if (!l) return false; // we can use the layout_decider object as the data pointer location_sp = (layout == eLibcxxStringLayoutModeDSC) ? layout_decider : l->GetChildAtIndex(2, true); ValueObjectSP size_vo(l->GetChildAtIndex(1, true)); if (!size_vo || !location_sp) return false; size = size_vo->GetValueAsUnsigned(0); return true; } } bool lldb_private::formatters::LibcxxWStringSummaryProvider( ValueObject &valobj, Stream &stream, const TypeSummaryOptions &summary_options) { uint64_t size = 0; ValueObjectSP location_sp; if (!ExtractLibcxxStringInfo(valobj, location_sp, size)) return false; if (size == 0) { stream.Printf("L\"\""); return true; } if (!location_sp) return false; DataExtractor extractor; StringPrinter::ReadBufferAndDumpToStreamOptions options(valobj); if (summary_options.GetCapping() == TypeSummaryCapping::eTypeSummaryCapped) { const auto max_size = valobj.GetTargetSP()->GetMaximumSizeOfStringSummary(); if (size > max_size) { size = max_size; options.SetIsTruncated(true); } } location_sp->GetPointeeData(extractor, 0, size); // std::wstring::size() is measured in 'characters', not bytes ClangASTContext *ast_context = ClangASTContext::GetScratch(*valobj.GetTargetSP()); if (!ast_context) return false; auto wchar_t_size = ast_context->GetBasicType(lldb::eBasicTypeWChar).GetByteSize(nullptr); if (!wchar_t_size) return false; options.SetData(extractor); options.SetStream(&stream); options.SetPrefixToken("L"); options.SetQuote('"'); options.SetSourceSize(size); options.SetBinaryZeroIsTerminator(false); switch (*wchar_t_size) { case 1: StringPrinter::ReadBufferAndDumpToStream< lldb_private::formatters::StringPrinter::StringElementType::UTF8>( options); break; case 2: lldb_private::formatters::StringPrinter::ReadBufferAndDumpToStream< lldb_private::formatters::StringPrinter::StringElementType::UTF16>( options); break; case 4: lldb_private::formatters::StringPrinter::ReadBufferAndDumpToStream< lldb_private::formatters::StringPrinter::StringElementType::UTF32>( options); break; default: stream.Printf("size for wchar_t is not valid"); return true; } return true; } template bool LibcxxStringSummaryProvider(ValueObject &valobj, Stream &stream, const TypeSummaryOptions &summary_options, std::string prefix_token = "") { uint64_t size = 0; ValueObjectSP location_sp; if (!ExtractLibcxxStringInfo(valobj, location_sp, size)) return false; if (size == 0) { stream.Printf("\"\""); return true; } if (!location_sp) return false; StringPrinter::ReadBufferAndDumpToStreamOptions options(valobj); DataExtractor extractor; if (summary_options.GetCapping() == TypeSummaryCapping::eTypeSummaryCapped) { const auto max_size = valobj.GetTargetSP()->GetMaximumSizeOfStringSummary(); if (size > max_size) { size = max_size; options.SetIsTruncated(true); } } location_sp->GetPointeeData(extractor, 0, size); options.SetData(extractor); options.SetStream(&stream); if (prefix_token.empty()) options.SetPrefixToken(nullptr); else options.SetPrefixToken(prefix_token); options.SetQuote('"'); options.SetSourceSize(size); options.SetBinaryZeroIsTerminator(false); StringPrinter::ReadBufferAndDumpToStream(options); return true; } bool lldb_private::formatters::LibcxxStringSummaryProviderASCII( ValueObject &valobj, Stream &stream, const TypeSummaryOptions &summary_options) { return LibcxxStringSummaryProvider( valobj, stream, summary_options); } bool lldb_private::formatters::LibcxxStringSummaryProviderUTF16( ValueObject &valobj, Stream &stream, const TypeSummaryOptions &summary_options) { return LibcxxStringSummaryProvider( valobj, stream, summary_options, "u"); } bool lldb_private::formatters::LibcxxStringSummaryProviderUTF32( ValueObject &valobj, Stream &stream, const TypeSummaryOptions &summary_options) { return LibcxxStringSummaryProvider( valobj, stream, summary_options, "U"); }