1 //===-- NSException.cpp ----------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "Cocoa.h"
11 
12 #include "lldb/Core/DataBufferHeap.h"
13 #include "lldb/Core/Error.h"
14 #include "lldb/Core/Stream.h"
15 #include "lldb/Core/ValueObject.h"
16 #include "lldb/Core/ValueObjectConstResult.h"
17 #include "lldb/DataFormatters/FormattersHelpers.h"
18 #include "lldb/Host/Endian.h"
19 #include "lldb/Symbol/ClangASTContext.h"
20 #include "lldb/Target/ObjCLanguageRuntime.h"
21 #include "lldb/Target/Target.h"
22 
23 #include "lldb/Utility/ProcessStructReader.h"
24 
25 #include "clang/AST/DeclCXX.h"
26 
27 #include "Plugins/Language/ObjC/NSString.h"
28 
29 using namespace lldb;
30 using namespace lldb_private;
31 using namespace lldb_private::formatters;
32 
33 bool
34 lldb_private::formatters::NSException_SummaryProvider (ValueObject& valobj, Stream& stream, const TypeSummaryOptions& options)
35 {
36     ProcessSP process_sp(valobj.GetProcessSP());
37     if (!process_sp)
38         return false;
39 
40     lldb::addr_t ptr_value = LLDB_INVALID_ADDRESS;
41 
42     CompilerType valobj_type(valobj.GetCompilerType());
43     Flags type_flags(valobj_type.GetTypeInfo());
44     if (type_flags.AllClear(eTypeHasValue))
45     {
46         if (valobj.IsBaseClass() && valobj.GetParent())
47             ptr_value = valobj.GetParent()->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
48     }
49     else
50         ptr_value = valobj.GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
51 
52     if (ptr_value == LLDB_INVALID_ADDRESS)
53         return false;
54     size_t ptr_size = process_sp->GetAddressByteSize();
55     lldb::addr_t name_location = ptr_value + 1 * ptr_size;
56     lldb::addr_t reason_location = ptr_value + 2 * ptr_size;
57 
58     Error error;
59     lldb::addr_t name = process_sp->ReadPointerFromMemory(name_location, error);
60     if (error.Fail() || name == LLDB_INVALID_ADDRESS)
61         return false;
62 
63     lldb::addr_t reason = process_sp->ReadPointerFromMemory(reason_location, error);
64     if (error.Fail() || reason == LLDB_INVALID_ADDRESS)
65         return false;
66 
67     InferiorSizedWord name_isw(name, *process_sp);
68     InferiorSizedWord reason_isw(reason, *process_sp);
69 
70     CompilerType voidstar = process_sp->GetTarget().GetScratchClangASTContext()->GetBasicType(lldb::eBasicTypeVoid).GetPointerType();
71 
72     ValueObjectSP name_sp = ValueObject::CreateValueObjectFromData("name_str", name_isw.GetAsData(process_sp->GetByteOrder()), valobj.GetExecutionContextRef(), voidstar);
73     ValueObjectSP reason_sp = ValueObject::CreateValueObjectFromData("reason_str", reason_isw.GetAsData(process_sp->GetByteOrder()), valobj.GetExecutionContextRef(), voidstar);
74 
75     if (!name_sp || !reason_sp)
76         return false;
77 
78     StreamString name_str_summary;
79     StreamString reason_str_summary;
80     if (NSStringSummaryProvider(*name_sp, name_str_summary, options) &&
81         NSStringSummaryProvider(*reason_sp, reason_str_summary, options) &&
82         name_str_summary.Empty() == false &&
83         reason_str_summary.Empty() == false)
84     {
85         stream.Printf("name: %s - reason: %s", name_str_summary.GetData(), reason_str_summary.GetData());
86         return true;
87     }
88     else
89         return false;
90 }
91 
92 class NSExceptionSyntheticFrontEnd : public SyntheticChildrenFrontEnd
93 {
94 public:
95     NSExceptionSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
96     SyntheticChildrenFrontEnd(*valobj_sp)
97     {}
98 
99     virtual size_t
100     CalculateNumChildren ()
101     {
102         if (m_child_ptr)
103             return 1;
104         if (m_child_sp)
105             return 1;
106         return 0;
107     }
108 
109     virtual lldb::ValueObjectSP
110     GetChildAtIndex (size_t idx)
111     {
112         if (idx != 0)
113             return lldb::ValueObjectSP();
114 
115         if (m_child_ptr)
116             return m_child_ptr->GetSP();
117         return m_child_sp;
118     }
119 
120     virtual bool
121     Update()
122     {
123         m_child_ptr = nullptr;
124         m_child_sp.reset();
125 
126         ProcessSP process_sp(m_backend.GetProcessSP());
127         if (!process_sp)
128             return false;
129 
130         lldb::addr_t userinfo_location = LLDB_INVALID_ADDRESS;
131 
132         CompilerType valobj_type(m_backend.GetCompilerType());
133         Flags type_flags(valobj_type.GetTypeInfo());
134         if (type_flags.AllClear(eTypeHasValue))
135         {
136             if (m_backend.IsBaseClass() && m_backend.GetParent())
137                 userinfo_location = m_backend.GetParent()->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
138         }
139         else
140             userinfo_location = m_backend.GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
141 
142         if (userinfo_location == LLDB_INVALID_ADDRESS)
143             return false;
144 
145         size_t ptr_size = process_sp->GetAddressByteSize();
146 
147         userinfo_location += 3 * ptr_size;
148         Error error;
149         lldb::addr_t userinfo = process_sp->ReadPointerFromMemory(userinfo_location, error);
150         if (userinfo == LLDB_INVALID_ADDRESS || error.Fail())
151             return false;
152         InferiorSizedWord isw(userinfo,*process_sp);
153         m_child_sp = ValueObject::CreateValueObjectFromData("userInfo",
154                                                             isw.GetAsData(process_sp->GetByteOrder()),
155                                                             m_backend.GetExecutionContextRef(),
156                                                             process_sp->GetTarget().GetScratchClangASTContext()->GetBasicType(lldb::eBasicTypeObjCID));
157         return false;
158     }
159 
160     virtual bool
161     MightHaveChildren ()
162     {
163         return true;
164     }
165 
166     virtual size_t
167     GetIndexOfChildWithName (const ConstString &name)
168     {
169         static ConstString g___userInfo("userInfo");
170         if (name == g___userInfo)
171             return 0;
172         return UINT32_MAX;
173     }
174 
175     virtual
176     ~NSExceptionSyntheticFrontEnd ()
177     {
178         // no need to delete m_child_ptr - it's kept alive by the cluster manager on our behalf
179     }
180 
181 private:
182     // the child here can be "real" (i.e. an actual child of the root) or synthetized from raw memory
183     // if the former, I need to store a plain pointer to it - or else a loop of references will cause this entire hierarchy of values to leak
184     // if the latter, then I need to store a SharedPointer to it - so that it only goes away when everyone else in the cluster goes away
185     // oh joy!
186     ValueObject* m_child_ptr;
187     ValueObjectSP m_child_sp;
188 };
189 
190 SyntheticChildrenFrontEnd*
191 lldb_private::formatters::NSExceptionSyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
192 {
193     lldb::ProcessSP process_sp (valobj_sp->GetProcessSP());
194     if (!process_sp)
195         return nullptr;
196     ObjCLanguageRuntime *runtime = (ObjCLanguageRuntime*)process_sp->GetLanguageRuntime(lldb::eLanguageTypeObjC);
197     if (!runtime)
198         return nullptr;
199 
200     ObjCLanguageRuntime::ClassDescriptorSP descriptor(runtime->GetClassDescriptor(*valobj_sp.get()));
201 
202     if (!descriptor.get() || !descriptor->IsValid())
203         return nullptr;
204 
205     const char* class_name = descriptor->GetClassName().GetCString();
206 
207     if (!class_name || !*class_name)
208         return nullptr;
209 
210     if (!strcmp(class_name,"NSException"))
211         return (new NSExceptionSyntheticFrontEnd(valobj_sp));
212     else if (!strcmp(class_name,"NSCFException"))
213         return (new NSExceptionSyntheticFrontEnd(valobj_sp));
214     else if (!strcmp(class_name,"__NSCFException"))
215         return (new NSExceptionSyntheticFrontEnd(valobj_sp));
216 
217     return nullptr;
218 }
219 
220