LLVM 20.0.0git
SectionKind.h
Go to the documentation of this file.
1//===-- llvm/MC/SectionKind.h - Classification of sections ------*- C++ -*-===//
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#ifndef LLVM_MC_SECTIONKIND_H
10#define LLVM_MC_SECTIONKIND_H
11
12namespace llvm {
13
14/// SectionKind - This is a simple POD value that classifies the properties of
15/// a section. A section is classified into the deepest possible
16/// classification, and then the target maps them onto their sections based on
17/// what capabilities they have.
18///
19/// The comments below describe these as if they were an inheritance hierarchy
20/// in order to explain the predicates below.
21///
23 enum Kind {
24 /// Metadata - Debug info sections or other metadata.
26
27 /// Exclude - This section will be excluded from the final executable or
28 /// shared library. Only valid for ELF / COFF targets.
29 Exclude,
30
31 /// Text - Text section, used for functions and other executable code.
32 Text,
33
34 /// ExecuteOnly, Text section that is not readable.
35 ExecuteOnly,
36
37 /// ReadOnly - Data that is never written to at program runtime by the
38 /// program or the dynamic linker. Things in the top-level readonly
39 /// SectionKind are not mergeable.
40 ReadOnly,
41
42 /// MergableCString - Any null-terminated string which allows merging.
43 /// These values are known to end in a nul value of the specified size,
44 /// not otherwise contain a nul value, and be mergable. This allows the
45 /// linker to unique the strings if it so desires.
46
47 /// Mergeable1ByteCString - 1 byte mergable, null terminated, string.
48 Mergeable1ByteCString,
49
50 /// Mergeable2ByteCString - 2 byte mergable, null terminated, string.
51 Mergeable2ByteCString,
52
53 /// Mergeable4ByteCString - 4 byte mergable, null terminated, string.
54 Mergeable4ByteCString,
55
56 /// MergeableConst - These are sections for merging fixed-length
57 /// constants together. For example, this can be used to unique
58 /// constant pool entries etc.
59
60 /// MergeableConst4 - This is a section used by 4-byte constants,
61 /// for example, floats.
62 MergeableConst4,
63
64 /// MergeableConst8 - This is a section used by 8-byte constants,
65 /// for example, doubles.
66 MergeableConst8,
67
68 /// MergeableConst16 - This is a section used by 16-byte constants,
69 /// for example, vectors.
70 MergeableConst16,
71
72 /// MergeableConst32 - This is a section used by 32-byte constants,
73 /// for example, vectors.
74 MergeableConst32,
75
76 /// Writeable - This is the base of all segments that need to be written
77 /// to during program runtime.
78
79 /// ThreadLocal - This is the base of all TLS segments. All TLS
80 /// objects must be writeable, otherwise there is no reason for them to
81 /// be thread local!
82
83 /// ThreadBSS - Zero-initialized TLS data objects.
84 ThreadBSS,
85
86 /// ThreadData - Initialized TLS data objects.
87 ThreadData,
88
89 /// ThreadBSSLocal - Zero-initialized TLS data objects with local linkage.
90 ThreadBSSLocal,
91
92 /// GlobalWriteableData - Writeable data that is global (not thread
93 /// local).
94
95 /// BSS - Zero initialized writeable data.
96 BSS,
97
98 /// BSSLocal - This is BSS (zero initialized and writable) data
99 /// which has local linkage.
100 BSSLocal,
101
102 /// BSSExtern - This is BSS data with normal external linkage.
103 BSSExtern,
104
105 /// Common - Data with common linkage. These represent tentative
106 /// definitions, which always have a zero initializer and are never
107 /// marked 'constant'.
108 Common,
109
110 /// This is writeable data that has a non-zero initializer.
111 Data,
112
113 /// ReadOnlyWithRel - These are global variables that are never
114 /// written to by the program, but that have relocations, so they
115 /// must be stuck in a writeable section so that the dynamic linker
116 /// can write to them. If it chooses to, the dynamic linker can
117 /// mark the pages these globals end up on as read-only after it is
118 /// done with its relocation phase.
119 ReadOnlyWithRel
120 } K : 8;
121public:
122
123 bool isMetadata() const { return K == Metadata; }
124
125 bool isExclude() const { return K == Exclude; }
126
127 bool isText() const { return K == Text || K == ExecuteOnly; }
128
129 bool isExecuteOnly() const { return K == ExecuteOnly; }
130
131 bool isReadOnly() const {
132 return K == ReadOnly || isMergeableCString() ||
134 }
135
136 bool isMergeableCString() const {
137 return K == Mergeable1ByteCString || K == Mergeable2ByteCString ||
138 K == Mergeable4ByteCString;
139 }
140 bool isMergeable1ByteCString() const { return K == Mergeable1ByteCString; }
141 bool isMergeable2ByteCString() const { return K == Mergeable2ByteCString; }
142 bool isMergeable4ByteCString() const { return K == Mergeable4ByteCString; }
143
144 bool isMergeableConst() const {
145 return K == MergeableConst4 || K == MergeableConst8 ||
146 K == MergeableConst16 || K == MergeableConst32;
147 }
148 bool isMergeableConst4() const { return K == MergeableConst4; }
149 bool isMergeableConst8() const { return K == MergeableConst8; }
150 bool isMergeableConst16() const { return K == MergeableConst16; }
151 bool isMergeableConst32() const { return K == MergeableConst32; }
152
153 bool isWriteable() const {
155 }
156
157 bool isThreadLocal() const {
158 return K == ThreadData || K == ThreadBSS || K == ThreadBSSLocal;
159 }
160
161 bool isThreadBSS() const { return K == ThreadBSS || K == ThreadBSSLocal; }
162 bool isThreadData() const { return K == ThreadData; }
163 bool isThreadBSSLocal() const { return K == ThreadBSSLocal; }
164
166 return isBSS() || isCommon() || isData() || isReadOnlyWithRel();
167 }
168
169 bool isBSS() const { return K == BSS || K == BSSLocal || K == BSSExtern; }
170 bool isBSSLocal() const { return K == BSSLocal; }
171 bool isBSSExtern() const { return K == BSSExtern; }
172
173 bool isCommon() const { return K == Common; }
174
175 bool isData() const { return K == Data; }
176
177 bool isReadOnlyWithRel() const {
178 return K == ReadOnlyWithRel;
179 }
180private:
181 static SectionKind get(Kind K) {
182 SectionKind Res;
183 Res.K = K;
184 return Res;
185 }
186public:
187
188 static SectionKind getMetadata() { return get(Metadata); }
189 static SectionKind getExclude() { return get(Exclude); }
190 static SectionKind getText() { return get(Text); }
191 static SectionKind getExecuteOnly() { return get(ExecuteOnly); }
192 static SectionKind getReadOnly() { return get(ReadOnly); }
194 return get(Mergeable1ByteCString);
195 }
197 return get(Mergeable2ByteCString);
198 }
200 return get(Mergeable4ByteCString);
201 }
202 static SectionKind getMergeableConst4() { return get(MergeableConst4); }
203 static SectionKind getMergeableConst8() { return get(MergeableConst8); }
204 static SectionKind getMergeableConst16() { return get(MergeableConst16); }
205 static SectionKind getMergeableConst32() { return get(MergeableConst32); }
206 static SectionKind getThreadBSS() { return get(ThreadBSS); }
207 static SectionKind getThreadData() { return get(ThreadData); }
208 static SectionKind getThreadBSSLocal() { return get(ThreadBSSLocal); }
209 static SectionKind getBSS() { return get(BSS); }
210 static SectionKind getBSSLocal() { return get(BSSLocal); }
211 static SectionKind getBSSExtern() { return get(BSSExtern); }
212 static SectionKind getCommon() { return get(Common); }
213 static SectionKind getData() { return get(Data); }
214 static SectionKind getReadOnlyWithRel() { return get(ReadOnlyWithRel); }
215};
216
217} // end namespace llvm
218
219#endif
Root of the metadata hierarchy.
Definition: Metadata.h:62
SectionKind - This is a simple POD value that classifies the properties of a section.
Definition: SectionKind.h:22
static SectionKind getThreadData()
Definition: SectionKind.h:207
bool isCommon() const
Definition: SectionKind.h:173
bool isBSS() const
Definition: SectionKind.h:169
static SectionKind getBSSExtern()
Definition: SectionKind.h:211
bool isMergeable2ByteCString() const
Definition: SectionKind.h:141
static SectionKind getMetadata()
Definition: SectionKind.h:188
bool isThreadBSSLocal() const
Definition: SectionKind.h:163
bool isReadOnlyWithRel() const
Definition: SectionKind.h:177
static SectionKind getMergeable2ByteCString()
Definition: SectionKind.h:196
bool isMergeableConst4() const
Definition: SectionKind.h:148
static SectionKind getExclude()
Definition: SectionKind.h:189
static SectionKind getBSSLocal()
Definition: SectionKind.h:210
static SectionKind getMergeableConst4()
Definition: SectionKind.h:202
static SectionKind getCommon()
Definition: SectionKind.h:212
static SectionKind getText()
Definition: SectionKind.h:190
static SectionKind getThreadBSSLocal()
Definition: SectionKind.h:208
static SectionKind getReadOnlyWithRel()
Definition: SectionKind.h:214
bool isMergeableConst() const
Definition: SectionKind.h:144
bool isBSSLocal() const
Definition: SectionKind.h:170
bool isMergeableConst8() const
Definition: SectionKind.h:149
static SectionKind getData()
Definition: SectionKind.h:213
bool isExclude() const
Definition: SectionKind.h:125
bool isMetadata() const
Definition: SectionKind.h:123
static SectionKind getMergeableConst8()
Definition: SectionKind.h:203
bool isMergeable1ByteCString() const
Definition: SectionKind.h:140
bool isThreadBSS() const
Definition: SectionKind.h:161
bool isThreadLocal() const
Definition: SectionKind.h:157
bool isBSSExtern() const
Definition: SectionKind.h:171
bool isText() const
Definition: SectionKind.h:127
static SectionKind getBSS()
Definition: SectionKind.h:209
static SectionKind getThreadBSS()
Definition: SectionKind.h:206
bool isMergeableConst32() const
Definition: SectionKind.h:151
bool isExecuteOnly() const
Definition: SectionKind.h:129
bool isThreadData() const
Definition: SectionKind.h:162
bool isReadOnly() const
Definition: SectionKind.h:131
bool isMergeableCString() const
Definition: SectionKind.h:136
static SectionKind getMergeableConst16()
Definition: SectionKind.h:204
bool isGlobalWriteableData() const
Definition: SectionKind.h:165
bool isMergeable4ByteCString() const
Definition: SectionKind.h:142
static SectionKind getMergeable4ByteCString()
Definition: SectionKind.h:199
bool isData() const
Definition: SectionKind.h:175
static SectionKind getExecuteOnly()
Definition: SectionKind.h:191
bool isMergeableConst16() const
Definition: SectionKind.h:150
static SectionKind getMergeable1ByteCString()
Definition: SectionKind.h:193
bool isWriteable() const
Definition: SectionKind.h:153
static SectionKind getReadOnly()
Definition: SectionKind.h:192
static SectionKind getMergeableConst32()
Definition: SectionKind.h:205
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18