1 //===-- MsvcStl.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 "MsvcStl.h"
10
11 #include "lldb/Core/Debugger.h"
12 #include "lldb/Core/FormatEntity.h"
13 #include "lldb/DataFormatters/StringPrinter.h"
14 #include "lldb/DataFormatters/TypeSummary.h"
15 #include "lldb/Utility/ConstString.h"
16 #include "lldb/Utility/Status.h"
17 #include "lldb/Utility/Stream.h"
18 #include "lldb/ValueObject/ValueObject.h"
19
20 #include "Plugins/Language/CPlusPlus/CxxStringTypes.h"
21
22 #include "lldb/lldb-forward.h"
23 #include <optional>
24 #include <tuple>
25
26 using namespace lldb;
27 using namespace lldb_private;
28 using namespace lldb_private::formatters;
29
30 using StringElementType = StringPrinter::StringElementType;
31
32 template <StringElementType element_type>
StringElementByteSize()33 static constexpr uint64_t StringElementByteSize() {
34 switch (element_type) {
35 case StringElementType::ASCII:
36 case StringElementType::UTF8:
37 return 1;
38 case StringElementType::UTF16:
39 return 2;
40 case StringElementType::UTF32:
41 return 3;
42 }
43 return 0;
44 }
45
ExtractMsvcStlStringData(ValueObject & valobj)46 static ValueObjectSP ExtractMsvcStlStringData(ValueObject &valobj) {
47 return valobj.GetChildAtNamePath({"_Mypair", "_Myval2"});
48 }
49
50 /// Determine the size in bytes of \p valobj (a MSVC STL std::string object) and
51 /// extract its data payload. Return the size + payload pair.
52 static std::optional<std::pair<uint64_t, ValueObjectSP>>
ExtractMsvcStlStringInfo(ValueObject & valobj,uint64_t element_size)53 ExtractMsvcStlStringInfo(ValueObject &valobj, uint64_t element_size) {
54 ValueObjectSP valobj_pair_sp = ExtractMsvcStlStringData(valobj);
55 if (!valobj_pair_sp || !valobj_pair_sp->GetError().Success())
56 return {};
57
58 ValueObjectSP size_sp = valobj_pair_sp->GetChildMemberWithName("_Mysize");
59 ValueObjectSP capacity_sp = valobj_pair_sp->GetChildMemberWithName("_Myres");
60 ValueObjectSP bx_sp = valobj_pair_sp->GetChildMemberWithName("_Bx");
61 if (!size_sp || !capacity_sp || !bx_sp)
62 return {};
63
64 bool success = false;
65 uint64_t size = size_sp->GetValueAsUnsigned(0, &success);
66 if (!success)
67 return {};
68 uint64_t capacity = capacity_sp->GetValueAsUnsigned(0, &success);
69 if (!success)
70 return {};
71
72 size_t bufSize = std::max<size_t>(16 / element_size, 1);
73 bool isShortString = capacity < bufSize;
74
75 if (isShortString) {
76 ValueObjectSP buf_sp = bx_sp->GetChildMemberWithName("_Buf");
77 if (buf_sp)
78 return std::make_pair(size, buf_sp);
79 return {};
80 }
81 ValueObjectSP ptr_sp = bx_sp->GetChildMemberWithName("_Ptr");
82 if (ptr_sp)
83 return std::make_pair(size, ptr_sp);
84 return {};
85 }
86
87 template <StringPrinter::StringElementType element_type>
88 static bool
MsvcStlStringSummaryProviderImpl(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,std::string prefix_token)89 MsvcStlStringSummaryProviderImpl(ValueObject &valobj, Stream &stream,
90 const TypeSummaryOptions &summary_options,
91 std::string prefix_token) {
92 auto string_info =
93 ExtractMsvcStlStringInfo(valobj, StringElementByteSize<element_type>());
94 if (!string_info)
95 return false;
96 auto [size, location_sp] = *string_info;
97
98 return StringBufferSummaryProvider<element_type>(
99 stream, summary_options, location_sp, size, prefix_token);
100 }
101 template <StringPrinter::StringElementType element_type>
formatStringImpl(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,std::string prefix_token)102 static bool formatStringImpl(ValueObject &valobj, Stream &stream,
103 const TypeSummaryOptions &summary_options,
104 std::string prefix_token) {
105 StreamString scratch_stream;
106 const bool success = MsvcStlStringSummaryProviderImpl<element_type>(
107 valobj, scratch_stream, summary_options, prefix_token);
108 if (success)
109 stream << scratch_stream.GetData();
110 else
111 stream << "Summary Unavailable";
112 return true;
113 }
114
IsMsvcStlStringType(ValueObject & valobj)115 bool lldb_private::formatters::IsMsvcStlStringType(ValueObject &valobj) {
116 std::vector<uint32_t> indexes;
117 return valobj.GetCompilerType().GetIndexOfChildMemberWithName("_Mypair", true,
118 indexes) > 0;
119 }
120
MsvcStlWStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)121 bool lldb_private::formatters::MsvcStlWStringSummaryProvider(
122 ValueObject &valobj, Stream &stream,
123 const TypeSummaryOptions &summary_options) {
124 return formatStringImpl<StringElementType::UTF16>(valobj, stream,
125 summary_options, "L");
126 }
127
128 template <>
MsvcStlStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)129 bool lldb_private::formatters::MsvcStlStringSummaryProvider<
130 StringElementType::ASCII>(ValueObject &valobj, Stream &stream,
131 const TypeSummaryOptions &summary_options) {
132 return MsvcStlStringSummaryProviderImpl<StringElementType::ASCII>(
133 valobj, stream, summary_options, "");
134 }
135 template <>
MsvcStlStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)136 bool lldb_private::formatters::MsvcStlStringSummaryProvider<
137 StringElementType::UTF8>(ValueObject &valobj, Stream &stream,
138 const TypeSummaryOptions &summary_options) {
139 return MsvcStlStringSummaryProviderImpl<StringElementType::UTF8>(
140 valobj, stream, summary_options, "u8");
141 }
142 template <>
MsvcStlStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)143 bool lldb_private::formatters::MsvcStlStringSummaryProvider<
144 StringElementType::UTF16>(ValueObject &valobj, Stream &stream,
145 const TypeSummaryOptions &summary_options) {
146 return MsvcStlStringSummaryProviderImpl<StringElementType::UTF16>(
147 valobj, stream, summary_options, "u");
148 }
149 template <>
MsvcStlStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)150 bool lldb_private::formatters::MsvcStlStringSummaryProvider<
151 StringElementType::UTF32>(ValueObject &valobj, Stream &stream,
152 const TypeSummaryOptions &summary_options) {
153 return MsvcStlStringSummaryProviderImpl<StringElementType::UTF32>(
154 valobj, stream, summary_options, "U");
155 }
156