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