1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
//===-- LibCxxSpan.cpp ----------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "LibCxx.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/DataFormatters/FormattersHelpers.h"
#include "lldb/Utility/ConstString.h"
#include "llvm/ADT/APSInt.h"
#include <optional>
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::formatters;
namespace lldb_private {
namespace formatters {
class LibcxxStdSpanSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
public:
LibcxxStdSpanSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
~LibcxxStdSpanSyntheticFrontEnd() override = default;
size_t CalculateNumChildren() override;
lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
/// Determines properties of the std::span<> associated with this object
//
// std::span can either be instantiated with a compile-time known
// extent or a std::dynamic_extent (this is the default if only the
// type template argument is provided). The layout of std::span
// depends on whether the extent is dynamic or not. For static
// extents (e.g., std::span<int, 9>):
//
// (std::__1::span<const int, 9>) s = {
// __data = 0x000000016fdff494
// }
//
// For dynamic extents, e.g., std::span<int>, the layout is:
//
// (std::__1::span<const int, 18446744073709551615>) s = {
// __data = 0x000000016fdff494
// __size = 6
// }
//
// This function checks for a '__size' member to determine the number
// of elements in the span. If no such member exists, we get the size
// from the only other place it can be: the template argument.
bool Update() override;
bool MightHaveChildren() override;
size_t GetIndexOfChildWithName(ConstString name) override;
private:
ValueObject *m_start = nullptr; ///< First element of span. Held, not owned.
CompilerType m_element_type{}; ///< Type of span elements.
size_t m_num_elements = 0; ///< Number of elements in span.
uint32_t m_element_size = 0; ///< Size in bytes of each span element.
};
lldb_private::formatters::LibcxxStdSpanSyntheticFrontEnd::
LibcxxStdSpanSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
: SyntheticChildrenFrontEnd(*valobj_sp) {
if (valobj_sp)
Update();
}
size_t lldb_private::formatters::LibcxxStdSpanSyntheticFrontEnd::
CalculateNumChildren() {
return m_num_elements;
}
lldb::ValueObjectSP
lldb_private::formatters::LibcxxStdSpanSyntheticFrontEnd::GetChildAtIndex(
size_t idx) {
if (!m_start)
return {};
uint64_t offset = idx * m_element_size;
offset = offset + m_start->GetValueAsUnsigned(0);
StreamString name;
name.Printf("[%" PRIu64 "]", (uint64_t)idx);
return CreateValueObjectFromAddress(name.GetString(), offset,
m_backend.GetExecutionContextRef(),
m_element_type);
}
bool lldb_private::formatters::LibcxxStdSpanSyntheticFrontEnd::Update() {
// Get element type.
ValueObjectSP data_type_finder_sp = GetChildMemberWithName(
m_backend, {ConstString("__data_"), ConstString("__data")});
if (!data_type_finder_sp)
return false;
m_element_type = data_type_finder_sp->GetCompilerType().GetPointeeType();
// Get element size.
if (std::optional<uint64_t> size = m_element_type.GetByteSize(nullptr)) {
m_element_size = *size;
// Get data.
if (m_element_size > 0) {
m_start = data_type_finder_sp.get();
}
// Get number of elements.
if (auto size_sp = GetChildMemberWithName(
m_backend, {ConstString("__size_"), ConstString("__size")})) {
m_num_elements = size_sp->GetValueAsUnsigned(0);
} else if (auto arg =
m_backend.GetCompilerType().GetIntegralTemplateArgument(1)) {
m_num_elements = arg->value.getLimitedValue();
}
}
return true;
}
bool lldb_private::formatters::LibcxxStdSpanSyntheticFrontEnd::
MightHaveChildren() {
return true;
}
size_t lldb_private::formatters::LibcxxStdSpanSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name) {
if (!m_start)
return UINT32_MAX;
return ExtractIndexFromString(name.GetCString());
}
lldb_private::SyntheticChildrenFrontEnd *
LibcxxStdSpanSyntheticFrontEndCreator(CXXSyntheticChildren *,
lldb::ValueObjectSP valobj_sp) {
if (!valobj_sp)
return nullptr;
CompilerType type = valobj_sp->GetCompilerType();
if (!type.IsValid() || type.GetNumTemplateArguments() != 2)
return nullptr;
return new LibcxxStdSpanSyntheticFrontEnd(valobj_sp);
}
} // namespace formatters
} // namespace lldb_private
|
