1 //===-- NSError.cpp -------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "clang/AST/DeclCXX.h" 10 11 #include "Cocoa.h" 12 13 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h" 14 #include "lldb/Core/ValueObject.h" 15 #include "lldb/Core/ValueObjectConstResult.h" 16 #include "lldb/DataFormatters/FormattersHelpers.h" 17 #include "lldb/Target/ProcessStructReader.h" 18 #include "lldb/Target/Target.h" 19 #include "lldb/Utility/DataBufferHeap.h" 20 #include "lldb/Utility/Endian.h" 21 #include "lldb/Utility/Status.h" 22 #include "lldb/Utility/Stream.h" 23 24 #include "Plugins/Language/ObjC/NSString.h" 25 #include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h" 26 27 using namespace lldb; 28 using namespace lldb_private; 29 using namespace lldb_private::formatters; 30 31 static lldb::addr_t DerefToNSErrorPointer(ValueObject &valobj) { 32 CompilerType valobj_type(valobj.GetCompilerType()); 33 Flags type_flags(valobj_type.GetTypeInfo()); 34 if (type_flags.AllClear(eTypeHasValue)) { 35 if (valobj.IsBaseClass() && valobj.GetParent()) 36 return valobj.GetParent()->GetValueAsUnsigned(LLDB_INVALID_ADDRESS); 37 } else { 38 lldb::addr_t ptr_value = valobj.GetValueAsUnsigned(LLDB_INVALID_ADDRESS); 39 if (type_flags.AllSet(eTypeIsPointer)) { 40 CompilerType pointee_type(valobj_type.GetPointeeType()); 41 Flags pointee_flags(pointee_type.GetTypeInfo()); 42 if (pointee_flags.AllSet(eTypeIsPointer)) { 43 if (ProcessSP process_sp = valobj.GetProcessSP()) { 44 Status error; 45 ptr_value = process_sp->ReadPointerFromMemory(ptr_value, error); 46 } 47 } 48 } 49 return ptr_value; 50 } 51 52 return LLDB_INVALID_ADDRESS; 53 } 54 55 bool lldb_private::formatters::NSError_SummaryProvider( 56 ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) { 57 ProcessSP process_sp(valobj.GetProcessSP()); 58 if (!process_sp) 59 return false; 60 61 lldb::addr_t ptr_value = DerefToNSErrorPointer(valobj); 62 if (ptr_value == LLDB_INVALID_ADDRESS) 63 return false; 64 65 size_t ptr_size = process_sp->GetAddressByteSize(); 66 lldb::addr_t code_location = ptr_value + 2 * ptr_size; 67 lldb::addr_t domain_location = ptr_value + 3 * ptr_size; 68 69 Status error; 70 uint64_t code = process_sp->ReadUnsignedIntegerFromMemory(code_location, 71 ptr_size, 0, error); 72 if (error.Fail()) 73 return false; 74 75 lldb::addr_t domain_str_value = 76 process_sp->ReadPointerFromMemory(domain_location, error); 77 if (error.Fail() || domain_str_value == LLDB_INVALID_ADDRESS) 78 return false; 79 80 if (!domain_str_value) { 81 stream.Printf("domain: nil - code: %" PRIu64, code); 82 return true; 83 } 84 85 InferiorSizedWord isw(domain_str_value, *process_sp); 86 87 ValueObjectSP domain_str_sp = ValueObject::CreateValueObjectFromData( 88 "domain_str", isw.GetAsData(process_sp->GetByteOrder()), 89 valobj.GetExecutionContextRef(), 90 ScratchTypeSystemClang::GetForTarget(process_sp->GetTarget()) 91 ->GetBasicType(lldb::eBasicTypeVoid) 92 .GetPointerType()); 93 94 if (!domain_str_sp) 95 return false; 96 97 StreamString domain_str_summary; 98 if (NSStringSummaryProvider(*domain_str_sp, domain_str_summary, options) && 99 !domain_str_summary.Empty()) { 100 stream.Printf("domain: %s - code: %" PRIu64, domain_str_summary.GetData(), 101 code); 102 return true; 103 } else { 104 stream.Printf("domain: nil - code: %" PRIu64, code); 105 return true; 106 } 107 } 108 109 class NSErrorSyntheticFrontEnd : public SyntheticChildrenFrontEnd { 110 public: 111 NSErrorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp) 112 : SyntheticChildrenFrontEnd(*valobj_sp) {} 113 114 ~NSErrorSyntheticFrontEnd() override = default; 115 // no need to delete m_child_ptr - it's kept alive by the cluster manager on 116 // our behalf 117 118 size_t CalculateNumChildren() override { 119 if (m_child_ptr) 120 return 1; 121 if (m_child_sp) 122 return 1; 123 return 0; 124 } 125 126 lldb::ValueObjectSP GetChildAtIndex(size_t idx) override { 127 if (idx != 0) 128 return lldb::ValueObjectSP(); 129 130 if (m_child_ptr) 131 return m_child_ptr->GetSP(); 132 return m_child_sp; 133 } 134 135 bool Update() override { 136 m_child_ptr = nullptr; 137 m_child_sp.reset(); 138 139 ProcessSP process_sp(m_backend.GetProcessSP()); 140 if (!process_sp) 141 return false; 142 143 lldb::addr_t userinfo_location = DerefToNSErrorPointer(m_backend); 144 if (userinfo_location == LLDB_INVALID_ADDRESS) 145 return false; 146 147 size_t ptr_size = process_sp->GetAddressByteSize(); 148 149 userinfo_location += 4 * ptr_size; 150 Status error; 151 lldb::addr_t userinfo = 152 process_sp->ReadPointerFromMemory(userinfo_location, error); 153 if (userinfo == LLDB_INVALID_ADDRESS || error.Fail()) 154 return false; 155 InferiorSizedWord isw(userinfo, *process_sp); 156 m_child_sp = CreateValueObjectFromData( 157 "_userInfo", isw.GetAsData(process_sp->GetByteOrder()), 158 m_backend.GetExecutionContextRef(), 159 ScratchTypeSystemClang::GetForTarget(process_sp->GetTarget()) 160 ->GetBasicType(lldb::eBasicTypeObjCID)); 161 return false; 162 } 163 164 bool MightHaveChildren() override { return true; } 165 166 size_t GetIndexOfChildWithName(ConstString name) override { 167 static ConstString g_userInfo("_userInfo"); 168 if (name == g_userInfo) 169 return 0; 170 return UINT32_MAX; 171 } 172 173 private: 174 // the child here can be "real" (i.e. an actual child of the root) or 175 // synthetized from raw memory if the former, I need to store a plain pointer 176 // to it - or else a loop of references will cause this entire hierarchy of 177 // values to leak if the latter, then I need to store a SharedPointer to it - 178 // so that it only goes away when everyone else in the cluster goes away oh 179 // joy! 180 ValueObject *m_child_ptr = nullptr; 181 ValueObjectSP m_child_sp; 182 }; 183 184 SyntheticChildrenFrontEnd * 185 lldb_private::formatters::NSErrorSyntheticFrontEndCreator( 186 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) { 187 lldb::ProcessSP process_sp(valobj_sp->GetProcessSP()); 188 if (!process_sp) 189 return nullptr; 190 ObjCLanguageRuntime *runtime = ObjCLanguageRuntime::Get(*process_sp); 191 if (!runtime) 192 return nullptr; 193 194 ObjCLanguageRuntime::ClassDescriptorSP descriptor( 195 runtime->GetClassDescriptor(*valobj_sp.get())); 196 197 if (!descriptor.get() || !descriptor->IsValid()) 198 return nullptr; 199 200 const char *class_name = descriptor->GetClassName().GetCString(); 201 202 if (!class_name || !*class_name) 203 return nullptr; 204 205 if (!strcmp(class_name, "NSError")) 206 return (new NSErrorSyntheticFrontEnd(valobj_sp)); 207 else if (!strcmp(class_name, "__NSCFError")) 208 return (new NSErrorSyntheticFrontEnd(valobj_sp)); 209 210 return nullptr; 211 } 212