1 //===-- NSException.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 "lldb/Core/ValueObject.h"
14 #include "lldb/Core/ValueObjectConstResult.h"
15 #include "lldb/DataFormatters/FormattersHelpers.h"
16 #include "lldb/Target/Target.h"
17 #include "lldb/Utility/DataBufferHeap.h"
18 #include "lldb/Utility/Endian.h"
19 #include "lldb/Utility/Status.h"
20 #include "lldb/Utility/Stream.h"
21 
22 #include "Plugins/Language/ObjC/NSString.h"
23 #include "Plugins/LanguageRuntime/ObjC/ObjCLanguageRuntime.h"
24 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
25 
26 using namespace lldb;
27 using namespace lldb_private;
28 using namespace lldb_private::formatters;
29 
30 static bool ExtractFields(ValueObject &valobj, ValueObjectSP *name_sp,
31                           ValueObjectSP *reason_sp, ValueObjectSP *userinfo_sp,
32                           ValueObjectSP *reserved_sp) {
33   ProcessSP process_sp(valobj.GetProcessSP());
34   if (!process_sp)
35     return false;
36 
37   lldb::addr_t ptr = LLDB_INVALID_ADDRESS;
38 
39   CompilerType valobj_type(valobj.GetCompilerType());
40   Flags type_flags(valobj_type.GetTypeInfo());
41   if (type_flags.AllClear(eTypeHasValue)) {
42     if (valobj.IsBaseClass() && valobj.GetParent())
43       ptr = valobj.GetParent()->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
44   } else {
45     ptr = valobj.GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
46   }
47 
48   if (ptr == LLDB_INVALID_ADDRESS)
49     return false;
50   size_t ptr_size = process_sp->GetAddressByteSize();
51 
52   Status error;
53   auto name = process_sp->ReadPointerFromMemory(ptr + 1 * ptr_size, error);
54   if (error.Fail() || name == LLDB_INVALID_ADDRESS)
55     return false;
56   auto reason = process_sp->ReadPointerFromMemory(ptr + 2 * ptr_size, error);
57   if (error.Fail() || reason == LLDB_INVALID_ADDRESS)
58     return false;
59   auto userinfo = process_sp->ReadPointerFromMemory(ptr + 3 * ptr_size, error);
60   if (error.Fail() || userinfo == LLDB_INVALID_ADDRESS)
61     return false;
62   auto reserved = process_sp->ReadPointerFromMemory(ptr + 4 * ptr_size, error);
63   if (error.Fail() || reserved == LLDB_INVALID_ADDRESS)
64     return false;
65 
66   InferiorSizedWord name_isw(name, *process_sp);
67   InferiorSizedWord reason_isw(reason, *process_sp);
68   InferiorSizedWord userinfo_isw(userinfo, *process_sp);
69   InferiorSizedWord reserved_isw(reserved, *process_sp);
70 
71   TypeSystemClangSP scratch_ts_sp =
72       ScratchTypeSystemClang::GetForTarget(process_sp->GetTarget());
73   if (!scratch_ts_sp)
74     return false;
75 
76   CompilerType voidstar =
77       scratch_ts_sp->GetBasicType(lldb::eBasicTypeVoid).GetPointerType();
78 
79   if (name_sp)
80     *name_sp = ValueObject::CreateValueObjectFromData(
81         "name", name_isw.GetAsData(process_sp->GetByteOrder()),
82         valobj.GetExecutionContextRef(), voidstar);
83   if (reason_sp)
84     *reason_sp = ValueObject::CreateValueObjectFromData(
85         "reason", reason_isw.GetAsData(process_sp->GetByteOrder()),
86         valobj.GetExecutionContextRef(), voidstar);
87   if (userinfo_sp)
88     *userinfo_sp = ValueObject::CreateValueObjectFromData(
89         "userInfo", userinfo_isw.GetAsData(process_sp->GetByteOrder()),
90         valobj.GetExecutionContextRef(), voidstar);
91   if (reserved_sp)
92     *reserved_sp = ValueObject::CreateValueObjectFromData(
93         "reserved", reserved_isw.GetAsData(process_sp->GetByteOrder()),
94         valobj.GetExecutionContextRef(), voidstar);
95 
96   return true;
97 }
98 
99 bool lldb_private::formatters::NSException_SummaryProvider(
100     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
101   lldb::ValueObjectSP reason_sp;
102   if (!ExtractFields(valobj, nullptr, &reason_sp, nullptr, nullptr))
103     return false;
104 
105   if (!reason_sp) {
106     stream.Printf("No reason");
107     return false;
108   }
109 
110   StreamString reason_str_summary;
111   if (NSStringSummaryProvider(*reason_sp, reason_str_summary, options) &&
112       !reason_str_summary.Empty()) {
113     stream.Printf("%s", reason_str_summary.GetData());
114     return true;
115   } else
116     return false;
117 }
118 
119 class NSExceptionSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
120 public:
121   NSExceptionSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
122       : SyntheticChildrenFrontEnd(*valobj_sp) {}
123 
124   ~NSExceptionSyntheticFrontEnd() override = default;
125 
126   size_t CalculateNumChildren() override {
127     return 4;
128   }
129 
130   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override {
131     switch (idx) {
132       case 0: return m_name_sp;
133       case 1: return m_reason_sp;
134       case 2: return m_userinfo_sp;
135       case 3: return m_reserved_sp;
136     }
137     return lldb::ValueObjectSP();
138   }
139 
140   bool Update() override {
141     m_name_sp.reset();
142     m_reason_sp.reset();
143     m_userinfo_sp.reset();
144     m_reserved_sp.reset();
145 
146     return ExtractFields(m_backend, &m_name_sp, &m_reason_sp, &m_userinfo_sp,
147                          &m_reserved_sp);
148   }
149 
150   bool MightHaveChildren() override { return true; }
151 
152   size_t GetIndexOfChildWithName(ConstString name) override {
153     // NSException has 4 members:
154     //   NSString *name;
155     //   NSString *reason;
156     //   NSDictionary *userInfo;
157     //   id reserved;
158     static ConstString g_name("name");
159     static ConstString g_reason("reason");
160     static ConstString g_userInfo("userInfo");
161     static ConstString g_reserved("reserved");
162     if (name == g_name) return 0;
163     if (name == g_reason) return 1;
164     if (name == g_userInfo) return 2;
165     if (name == g_reserved) return 3;
166     return UINT32_MAX;
167   }
168 
169 private:
170   ValueObjectSP m_name_sp;
171   ValueObjectSP m_reason_sp;
172   ValueObjectSP m_userinfo_sp;
173   ValueObjectSP m_reserved_sp;
174 };
175 
176 SyntheticChildrenFrontEnd *
177 lldb_private::formatters::NSExceptionSyntheticFrontEndCreator(
178     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
179   lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
180   if (!process_sp)
181     return nullptr;
182   ObjCLanguageRuntime *runtime = ObjCLanguageRuntime::Get(*process_sp);
183   if (!runtime)
184     return nullptr;
185 
186   ObjCLanguageRuntime::ClassDescriptorSP descriptor(
187       runtime->GetClassDescriptor(*valobj_sp.get()));
188 
189   if (!descriptor.get() || !descriptor->IsValid())
190     return nullptr;
191 
192   const char *class_name = descriptor->GetClassName().GetCString();
193 
194   if (!class_name || !*class_name)
195     return nullptr;
196 
197   if (!strcmp(class_name, "NSException"))
198     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
199   else if (!strcmp(class_name, "NSCFException"))
200     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
201   else if (!strcmp(class_name, "__NSCFException"))
202     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
203 
204   return nullptr;
205 }
206