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
26using namespace lldb;
27using namespace lldb_private;
28using namespace lldb_private::formatters;
29
30using StringElementType = StringPrinter::StringElementType;
31
32template <StringElementType element_type>
33static 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
46static ValueObjectSP ExtractMsvcStlStringData(ValueObject &valobj) {
47 return valobj.GetChildAtNamePath(names: {"_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.
52static std::optional<std::pair<uint64_t, ValueObjectSP>>
53ExtractMsvcStlStringInfo(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(name: "_Mysize");
59 ValueObjectSP capacity_sp = valobj_pair_sp->GetChildMemberWithName(name: "_Myres");
60 ValueObjectSP bx_sp = valobj_pair_sp->GetChildMemberWithName(name: "_Bx");
61 if (!size_sp || !capacity_sp || !bx_sp)
62 return {};
63
64 bool success = false;
65 uint64_t size = size_sp->GetValueAsUnsigned(fail_value: 0, success: &success);
66 if (!success)
67 return {};
68 uint64_t capacity = capacity_sp->GetValueAsUnsigned(fail_value: 0, success: &success);
69 if (!success)
70 return {};
71
72 size_t bufSize = std::max<size_t>(a: 16 / element_size, b: 1);
73 bool isShortString = capacity < bufSize;
74
75 if (isShortString) {
76 ValueObjectSP buf_sp = bx_sp->GetChildMemberWithName(name: "_Buf");
77 if (buf_sp)
78 return std::make_pair(x&: size, y&: buf_sp);
79 return {};
80 }
81 ValueObjectSP ptr_sp = bx_sp->GetChildMemberWithName(name: "_Ptr");
82 if (ptr_sp)
83 return std::make_pair(x&: size, y&: ptr_sp);
84 return {};
85}
86
87template <StringPrinter::StringElementType element_type>
88static bool
89MsvcStlStringSummaryProviderImpl(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}
101template <StringPrinter::StringElementType element_type>
102static 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
115bool lldb_private::formatters::IsMsvcStlStringType(ValueObject &valobj) {
116 std::vector<uint32_t> indexes;
117 return valobj.GetCompilerType().GetIndexOfChildMemberWithName(name: "_Mypair", omit_empty_base_classes: true,
118 child_indexes&: indexes) > 0;
119}
120
121bool lldb_private::formatters::MsvcStlWStringSummaryProvider(
122 ValueObject &valobj, Stream &stream,
123 const TypeSummaryOptions &summary_options) {
124 return formatStringImpl<StringElementType::UTF16>(valobj, stream,
125 summary_options, prefix_token: "L");
126}
127
128template <>
129bool 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, prefix_token: "");
134}
135template <>
136bool 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, prefix_token: "u8");
141}
142template <>
143bool 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, prefix_token: "u");
148}
149template <>
150bool 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, prefix_token: "U");
155}
156

source code of lldb/source/Plugins/Language/CPlusPlus/MsvcStl.cpp