1 //===-- TypeFormat.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 "lldb/DataFormatters/TypeFormat.h"
10 
11 
12 
13 
14 #include "lldb/lldb-enumerations.h"
15 #include "lldb/lldb-public.h"
16 
17 #include "lldb/Core/DumpDataExtractor.h"
18 #include "lldb/DataFormatters/FormatManager.h"
19 #include "lldb/Symbol/CompilerType.h"
20 #include "lldb/Symbol/SymbolContext.h"
21 #include "lldb/Symbol/SymbolFile.h"
22 #include "lldb/Symbol/TypeList.h"
23 #include "lldb/Target/Target.h"
24 #include "lldb/Utility/DataExtractor.h"
25 #include "lldb/Utility/StreamString.h"
26 #include <optional>
27 
28 using namespace lldb;
29 using namespace lldb_private;
30 
31 TypeFormatImpl::TypeFormatImpl(const Flags &flags) : m_flags(flags) {}
32 
33 TypeFormatImpl::~TypeFormatImpl() = default;
34 
35 TypeFormatImpl_Format::TypeFormatImpl_Format(lldb::Format f,
36                                              const TypeFormatImpl::Flags &flags)
37     : TypeFormatImpl(flags), m_format(f) {}
38 
39 TypeFormatImpl_Format::~TypeFormatImpl_Format() = default;
40 
41 bool TypeFormatImpl_Format::FormatObject(ValueObject *valobj,
42                                          std::string &dest) const {
43   if (!valobj)
44     return false;
45   if (valobj->CanProvideValue()) {
46     Value &value(valobj->GetValue());
47     const Value::ContextType context_type = value.GetContextType();
48     ExecutionContext exe_ctx(valobj->GetExecutionContextRef());
49     DataExtractor data;
50 
51     if (context_type == Value::ContextType::RegisterInfo) {
52       const RegisterInfo *reg_info = value.GetRegisterInfo();
53       if (reg_info) {
54         Status error;
55         valobj->GetData(data, error);
56         if (error.Fail())
57           return false;
58 
59         StreamString reg_sstr;
60         DumpDataExtractor(data, &reg_sstr, 0, GetFormat(), reg_info->byte_size,
61                           1, UINT32_MAX, LLDB_INVALID_ADDRESS, 0, 0,
62                           exe_ctx.GetBestExecutionContextScope());
63         dest = std::string(reg_sstr.GetString());
64       }
65     } else {
66       CompilerType compiler_type = value.GetCompilerType();
67       if (compiler_type) {
68         // put custom bytes to display in the DataExtractor to override the
69         // default value logic
70         if (GetFormat() == eFormatCString) {
71           lldb_private::Flags type_flags(compiler_type.GetTypeInfo(
72               nullptr)); // disambiguate w.r.t. TypeFormatImpl::Flags
73           if (type_flags.Test(eTypeIsPointer) &&
74               !type_flags.Test(eTypeIsObjC)) {
75             // if we are dumping a pointer as a c-string, get the pointee data
76             // as a string
77             TargetSP target_sp(valobj->GetTargetSP());
78             if (target_sp) {
79               size_t max_len = target_sp->GetMaximumSizeOfStringSummary();
80               Status error;
81               WritableDataBufferSP buffer_sp(
82                   new DataBufferHeap(max_len + 1, 0));
83               Address address(valobj->GetPointerValue());
84               target_sp->ReadCStringFromMemory(
85                   address, (char *)buffer_sp->GetBytes(), max_len, error);
86               if (error.Success())
87                 data.SetData(buffer_sp);
88             }
89           }
90         } else {
91           Status error;
92           valobj->GetData(data, error);
93           if (error.Fail())
94             return false;
95         }
96 
97         ExecutionContextScope *exe_scope =
98             exe_ctx.GetBestExecutionContextScope();
99         std::optional<uint64_t> size = compiler_type.GetByteSize(exe_scope);
100         if (!size)
101           return false;
102         StreamString sstr;
103         compiler_type.DumpTypeValue(
104             &sstr,                          // The stream to use for display
105             GetFormat(),                    // Format to display this type with
106             data,                           // Data to extract from
107             0,                              // Byte offset into "m_data"
108             *size,                          // Byte size of item in "m_data"
109             valobj->GetBitfieldBitSize(),   // Bitfield bit size
110             valobj->GetBitfieldBitOffset(), // Bitfield bit offset
111             exe_scope);
112         // Given that we do not want to set the ValueObject's m_error for a
113         // formatting error (or else we wouldn't be able to reformat until a
114         // next update), an empty string is treated as a "false" return from
115         // here, but that's about as severe as we get
116         // CompilerType::DumpTypeValue() should always return something, even
117         // if that something is an error message
118         dest = std::string(sstr.GetString());
119       }
120     }
121     return !dest.empty();
122   } else
123     return false;
124 }
125 
126 std::string TypeFormatImpl_Format::GetDescription() {
127   StreamString sstr;
128   sstr.Printf("%s%s%s%s", FormatManager::GetFormatAsCString(GetFormat()),
129               Cascades() ? "" : " (not cascading)",
130               SkipsPointers() ? " (skip pointers)" : "",
131               SkipsReferences() ? " (skip references)" : "");
132   return std::string(sstr.GetString());
133 }
134 
135 TypeFormatImpl_EnumType::TypeFormatImpl_EnumType(
136     ConstString type_name, const TypeFormatImpl::Flags &flags)
137     : TypeFormatImpl(flags), m_enum_type(type_name), m_types() {}
138 
139 TypeFormatImpl_EnumType::~TypeFormatImpl_EnumType() = default;
140 
141 bool TypeFormatImpl_EnumType::FormatObject(ValueObject *valobj,
142                                            std::string &dest) const {
143   dest.clear();
144   if (!valobj)
145     return false;
146   if (!valobj->CanProvideValue())
147     return false;
148   ProcessSP process_sp;
149   TargetSP target_sp;
150   void *valobj_key = (process_sp = valobj->GetProcessSP()).get();
151   if (!valobj_key)
152     valobj_key = (target_sp = valobj->GetTargetSP()).get();
153   else
154     target_sp = process_sp->GetTarget().shared_from_this();
155   if (!valobj_key)
156     return false;
157   auto iter = m_types.find(valobj_key), end = m_types.end();
158   CompilerType valobj_enum_type;
159   if (iter == end) {
160     // probably a redundant check
161     if (!target_sp)
162       return false;
163     const ModuleList &images(target_sp->GetImages());
164     TypeQuery query(m_enum_type.GetStringRef());
165     TypeResults results;
166     images.FindTypes(nullptr, query, results);
167     if (results.GetTypeMap().Empty())
168       return false;
169     for (lldb::TypeSP type_sp : results.GetTypeMap().Types()) {
170       if (!type_sp)
171         continue;
172       if ((type_sp->GetForwardCompilerType().GetTypeInfo() &
173            eTypeIsEnumeration) == eTypeIsEnumeration) {
174         valobj_enum_type = type_sp->GetFullCompilerType();
175         m_types.emplace(valobj_key, valobj_enum_type);
176         break;
177       }
178     }
179   } else
180     valobj_enum_type = iter->second;
181   if (!valobj_enum_type.IsValid())
182     return false;
183   DataExtractor data;
184   Status error;
185   valobj->GetData(data, error);
186   if (error.Fail())
187     return false;
188   ExecutionContext exe_ctx(valobj->GetExecutionContextRef());
189   StreamString sstr;
190   valobj_enum_type.DumpTypeValue(&sstr, lldb::eFormatEnum, data, 0,
191                                  data.GetByteSize(), 0, 0,
192                                  exe_ctx.GetBestExecutionContextScope());
193   if (!sstr.GetString().empty())
194     dest = std::string(sstr.GetString());
195   return !dest.empty();
196 }
197 
198 std::string TypeFormatImpl_EnumType::GetDescription() {
199   StreamString sstr;
200   sstr.Printf("as type %s%s%s%s", m_enum_type.AsCString("<invalid type>"),
201               Cascades() ? "" : " (not cascading)",
202               SkipsPointers() ? " (skip pointers)" : "",
203               SkipsReferences() ? " (skip references)" : "");
204   return std::string(sstr.GetString());
205 }
206