1 //===-- NSException.cpp -----------------------------------------*- C++ -*-===//
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/Symbol/ClangASTContext.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 bool ExtractFields(ValueObject &valobj, ValueObjectSP *name_sp,
32                           ValueObjectSP *reason_sp, ValueObjectSP *userinfo_sp,
33                           ValueObjectSP *reserved_sp) {
34   ProcessSP process_sp(valobj.GetProcessSP());
35   if (!process_sp)
36     return false;
37 
38   lldb::addr_t ptr = LLDB_INVALID_ADDRESS;
39 
40   CompilerType valobj_type(valobj.GetCompilerType());
41   Flags type_flags(valobj_type.GetTypeInfo());
42   if (type_flags.AllClear(eTypeHasValue)) {
43     if (valobj.IsBaseClass() && valobj.GetParent())
44       ptr = valobj.GetParent()->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
45   } else {
46     ptr = valobj.GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
47   }
48 
49   if (ptr == LLDB_INVALID_ADDRESS)
50     return false;
51   size_t ptr_size = process_sp->GetAddressByteSize();
52 
53   Status error;
54   auto name = process_sp->ReadPointerFromMemory(ptr + 1 * ptr_size, error);
55   if (error.Fail() || name == LLDB_INVALID_ADDRESS)
56     return false;
57   auto reason = process_sp->ReadPointerFromMemory(ptr + 2 * ptr_size, error);
58   if (error.Fail() || reason == LLDB_INVALID_ADDRESS)
59     return false;
60   auto userinfo = process_sp->ReadPointerFromMemory(ptr + 3 * ptr_size, error);
61   if (error.Fail() || userinfo == LLDB_INVALID_ADDRESS)
62     return false;
63   auto reserved = process_sp->ReadPointerFromMemory(ptr + 4 * ptr_size, error);
64   if (error.Fail() || reserved == LLDB_INVALID_ADDRESS)
65     return false;
66 
67   InferiorSizedWord name_isw(name, *process_sp);
68   InferiorSizedWord reason_isw(reason, *process_sp);
69   InferiorSizedWord userinfo_isw(userinfo, *process_sp);
70   InferiorSizedWord reserved_isw(reserved, *process_sp);
71 
72   auto *clang_ast_context = ClangASTContext::GetScratch(process_sp->GetTarget());
73   if (!clang_ast_context)
74     return false;
75 
76   CompilerType voidstar =
77       clang_ast_context->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 name_sp;
102   lldb::ValueObjectSP reason_sp;
103   if (!ExtractFields(valobj, &name_sp, &reason_sp, nullptr, nullptr))
104     return false;
105 
106   if (!name_sp || !reason_sp)
107     return false;
108 
109   StreamString name_str_summary;
110   StreamString reason_str_summary;
111   if (NSStringSummaryProvider(*name_sp, name_str_summary, options) &&
112       NSStringSummaryProvider(*reason_sp, reason_str_summary, options) &&
113       !name_str_summary.Empty() && !reason_str_summary.Empty()) {
114     stream.Printf("name: %s - reason: %s", name_str_summary.GetData(),
115                   reason_str_summary.GetData());
116     return true;
117   } else
118     return false;
119 }
120 
121 class NSExceptionSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
122 public:
123   NSExceptionSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
124       : SyntheticChildrenFrontEnd(*valobj_sp) {}
125 
126   ~NSExceptionSyntheticFrontEnd() override = default;
127 
128   size_t CalculateNumChildren() override {
129     return 4;
130   }
131 
132   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override {
133     switch (idx) {
134       case 0: return m_name_sp;
135       case 1: return m_reason_sp;
136       case 2: return m_userinfo_sp;
137       case 3: return m_reserved_sp;
138     }
139     return lldb::ValueObjectSP();
140   }
141 
142   bool Update() override {
143     m_name_sp.reset();
144     m_reason_sp.reset();
145     m_userinfo_sp.reset();
146     m_reserved_sp.reset();
147 
148     return ExtractFields(m_backend, &m_name_sp, &m_reason_sp, &m_userinfo_sp,
149                          &m_reserved_sp);
150   }
151 
152   bool MightHaveChildren() override { return true; }
153 
154   size_t GetIndexOfChildWithName(ConstString name) override {
155     // NSException has 4 members:
156     //   NSString *name;
157     //   NSString *reason;
158     //   NSDictionary *userInfo;
159     //   id reserved;
160     static ConstString g___name("name");
161     static ConstString g___reason("reason");
162     static ConstString g___userInfo("userInfo");
163     static ConstString g___reserved("reserved");
164     if (name == g___name) return 0;
165     if (name == g___reason) return 1;
166     if (name == g___userInfo) return 2;
167     if (name == g___reserved) return 3;
168     return UINT32_MAX;
169   }
170 
171 private:
172   ValueObjectSP m_name_sp;
173   ValueObjectSP m_reason_sp;
174   ValueObjectSP m_userinfo_sp;
175   ValueObjectSP m_reserved_sp;
176 };
177 
178 SyntheticChildrenFrontEnd *
179 lldb_private::formatters::NSExceptionSyntheticFrontEndCreator(
180     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
181   lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
182   if (!process_sp)
183     return nullptr;
184   ObjCLanguageRuntime *runtime = ObjCLanguageRuntime::Get(*process_sp);
185   if (!runtime)
186     return nullptr;
187 
188   ObjCLanguageRuntime::ClassDescriptorSP descriptor(
189       runtime->GetClassDescriptor(*valobj_sp.get()));
190 
191   if (!descriptor.get() || !descriptor->IsValid())
192     return nullptr;
193 
194   const char *class_name = descriptor->GetClassName().GetCString();
195 
196   if (!class_name || !*class_name)
197     return nullptr;
198 
199   if (!strcmp(class_name, "NSException"))
200     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
201   else if (!strcmp(class_name, "NSCFException"))
202     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
203   else if (!strcmp(class_name, "__NSCFException"))
204     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
205 
206   return nullptr;
207 }
208