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
DerefToNSErrorPointer(ValueObject & valobj)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
NSError_SummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)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:
NSErrorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)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
CalculateNumChildren()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
GetChildAtIndex(size_t idx)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
Update()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
MightHaveChildren()164 bool MightHaveChildren() override { return true; }
165
GetIndexOfChildWithName(ConstString name)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;
181 ValueObjectSP m_child_sp;
182 };
183
184 SyntheticChildrenFrontEnd *
NSErrorSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)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