source/Plugins/Language/ObjC/NSException.cpp

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