lldb/source/Plugins/Language/ObjC/NSException.cpp

   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/DataFormatters/FormattersHelpers.h"
  14 #include "lldb/Target/Target.h"
  15 #include "lldb/Utility/DataBufferHeap.h"
  16 #include "lldb/Utility/Endian.h"
  17 #include "lldb/Utility/Status.h"
  18 #include "lldb/Utility/Stream.h"
  19 #include "lldb/ValueObject/ValueObject.h"
  20 #include "lldb/ValueObject/ValueObjectConstResult.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   llvm::Expected<uint32_t> CalculateNumChildren() override { return 4; }
 127
 128   lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override {
 129     switch (idx) {
 130       case 0: return m_name_sp;
 131       case 1: return m_reason_sp;
 132       case 2: return m_userinfo_sp;
 133       case 3: return m_reserved_sp;
 134     }
 135     return lldb::ValueObjectSP();
 136   }
 137
 138   lldb::ChildCacheState Update() override {
 139     m_name_sp.reset();
 140     m_reason_sp.reset();
 141     m_userinfo_sp.reset();
 142     m_reserved_sp.reset();
 143
 144     const auto ret = ExtractFields(m_backend, &m_name_sp, &m_reason_sp,
 145                                    &m_userinfo_sp, &m_reserved_sp);
 146
 147     return ret ? lldb::ChildCacheState::eReuse
 148                : lldb::ChildCacheState::eRefetch;
 149   }
 150
 151   bool MightHaveChildren() override { return true; }
 152
 153   size_t GetIndexOfChildWithName(ConstString name) override {
 154     // NSException has 4 members:
 155     //   NSString *name;
 156     //   NSString *reason;
 157     //   NSDictionary *userInfo;
 158     //   id reserved;
 159     static ConstString g_name("name");
 160     static ConstString g_reason("reason");
 161     static ConstString g_userInfo("userInfo");
 162     static ConstString g_reserved("reserved");
 163     if (name == g_name) return 0;
 164     if (name == g_reason) return 1;
 165     if (name == g_userInfo) return 2;
 166     if (name == g_reserved) return 3;
 167     return UINT32_MAX;
 168   }
 169
 170 private:
 171   ValueObjectSP m_name_sp;
 172   ValueObjectSP m_reason_sp;
 173   ValueObjectSP m_userinfo_sp;
 174   ValueObjectSP m_reserved_sp;
 175 };
 176
 177 SyntheticChildrenFrontEnd *
 178 lldb_private::formatters::NSExceptionSyntheticFrontEndCreator(
 179     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
 180   lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
 181   if (!process_sp)
 182     return nullptr;
 183   ObjCLanguageRuntime *runtime = ObjCLanguageRuntime::Get(*process_sp);
 184   if (!runtime)
 185     return nullptr;
 186
 187   ObjCLanguageRuntime::ClassDescriptorSP descriptor(
 188       runtime->GetClassDescriptor(*valobj_sp.get()));
 189
 190   if (!descriptor.get() || !descriptor->IsValid())
 191     return nullptr;
 192
 193   const char *class_name = descriptor->GetClassName().GetCString();
 194
 195   if (!class_name || !*class_name)
 196     return nullptr;
 197
 198   if (!strcmp(class_name, "NSException"))
 199     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
 200   else if (!strcmp(class_name, "NSCFException"))
 201     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
 202   else if (!strcmp(class_name, "__NSCFException"))
 203     return (new NSExceptionSyntheticFrontEnd(valobj_sp));
 204
 205   return nullptr;
 206 }