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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
//===-- ELFTargetAsmInfo.cpp - ELF asm properties ---------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines target asm properties related what form asm statements
// should take in general on ELF-based targets
//
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/Target/ELFTargetAsmInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetData.h"
using namespace llvm;
ELFTargetAsmInfo::ELFTargetAsmInfo(const TargetMachine &TM)
: TargetAsmInfo(TM) {
BSSSection_ = getUnnamedSection("\t.bss",
SectionFlags::Writeable | SectionFlags::BSS);
ReadOnlySection = getNamedSection("\t.rodata", SectionFlags::None);
TLSDataSection = getNamedSection("\t.tdata",
SectionFlags::Writeable | SectionFlags::TLS);
TLSBSSSection = getNamedSection("\t.tbss",
SectionFlags::Writeable | SectionFlags::TLS | SectionFlags::BSS);
}
const Section*
ELFTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
SectionKind::Kind Kind = SectionKindForGlobal(GV);
if (const Function *F = dyn_cast<Function>(GV)) {
switch (F->getLinkage()) {
default: assert(0 && "Unknown linkage type!");
case Function::PrivateLinkage:
case Function::InternalLinkage:
case Function::DLLExportLinkage:
case Function::ExternalLinkage:
return TextSection;
case Function::WeakLinkage:
case Function::LinkOnceLinkage:
std::string Name = UniqueSectionForGlobal(GV, Kind);
unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str());
return getNamedSection(Name.c_str(), Flags);
}
} else if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
if (GVar->mayBeOverridden()) {
std::string Name = UniqueSectionForGlobal(GVar, Kind);
unsigned Flags = SectionFlagsForGlobal(GVar, Name.c_str());
return getNamedSection(Name.c_str(), Flags);
} else {
switch (Kind) {
case SectionKind::Data:
case SectionKind::SmallData:
return DataSection;
case SectionKind::BSS:
case SectionKind::SmallBSS:
// ELF targets usually have BSS sections
return getBSSSection_();
case SectionKind::ROData:
case SectionKind::SmallROData:
return getReadOnlySection();
case SectionKind::RODataMergeStr:
return MergeableStringSection(GVar);
case SectionKind::RODataMergeConst:
return MergeableConstSection(GVar);
case SectionKind::ThreadData:
// ELF targets usually support TLS stuff
return TLSDataSection;
case SectionKind::ThreadBSS:
return TLSBSSSection;
default:
assert(0 && "Unsuported section kind for global");
}
}
} else
assert(0 && "Unsupported global");
return NULL;
}
const Section*
ELFTargetAsmInfo::SelectSectionForMachineConst(const Type *Ty) const {
// FIXME: Support data.rel stuff someday
return MergeableConstSection(Ty);
}
const Section*
ELFTargetAsmInfo::MergeableConstSection(const GlobalVariable *GV) const {
Constant *C = GV->getInitializer();
return MergeableConstSection(C->getType());
}
inline const Section*
ELFTargetAsmInfo::MergeableConstSection(const Type *Ty) const {
const TargetData *TD = TM.getTargetData();
// FIXME: string here is temporary, until stuff will fully land in.
// We cannot use {Four,Eight,Sixteen}ByteConstantSection here, since it's
// currently directly used by asmprinter.
unsigned Size = TD->getTypePaddedSize(Ty);
if (Size == 4 || Size == 8 || Size == 16) {
std::string Name = ".rodata.cst" + utostr(Size);
return getNamedSection(Name.c_str(),
SectionFlags::setEntitySize(SectionFlags::Mergeable,
Size));
}
return getReadOnlySection();
}
const Section*
ELFTargetAsmInfo::MergeableStringSection(const GlobalVariable *GV) const {
const TargetData *TD = TM.getTargetData();
Constant *C = cast<GlobalVariable>(GV)->getInitializer();
const ConstantArray *CVA = cast<ConstantArray>(C);
const Type *Ty = CVA->getType()->getElementType();
unsigned Size = TD->getTypePaddedSize(Ty);
if (Size <= 16) {
assert(getCStringSection() && "Should have string section prefix");
// We also need alignment here
unsigned Align = TD->getPrefTypeAlignment(Ty);
if (Align < Size)
Align = Size;
std::string Name = getCStringSection() + utostr(Size) + '.' + utostr(Align);
unsigned Flags = SectionFlags::setEntitySize(SectionFlags::Mergeable |
SectionFlags::Strings,
Size);
return getNamedSection(Name.c_str(), Flags);
}
return getReadOnlySection();
}
std::string ELFTargetAsmInfo::printSectionFlags(unsigned flags) const {
std::string Flags = ",\"";
if (!(flags & SectionFlags::Debug))
Flags += 'a';
if (flags & SectionFlags::Code)
Flags += 'x';
if (flags & SectionFlags::Writeable)
Flags += 'w';
if (flags & SectionFlags::Mergeable)
Flags += 'M';
if (flags & SectionFlags::Strings)
Flags += 'S';
if (flags & SectionFlags::TLS)
Flags += 'T';
if (flags & SectionFlags::Small)
Flags += 's';
Flags += "\",";
// If comment string is '@', e.g. as on ARM - use '%' instead
if (strcmp(CommentString, "@") == 0)
Flags += '%';
else
Flags += '@';
// FIXME: There can be exceptions here
if (flags & SectionFlags::BSS)
Flags += "nobits";
else
Flags += "progbits";
if (unsigned entitySize = SectionFlags::getEntitySize(flags))
Flags += "," + utostr(entitySize);
return Flags;
}
|
