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
|
//===- MCAsmInfoCOFF.cpp - COFF asm properties ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file defines target asm properties related what form asm statements
// should take in general on COFF-based targets
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCAsmInfoCOFF.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
using namespace llvm;
void MCAsmInfoCOFF::anchor() {}
MCAsmInfoCOFF::MCAsmInfoCOFF() {
// MingW 4.5 and later support .comm with log2 alignment, but .lcomm uses byte
// alignment.
COMMDirectiveAlignmentIsInBytes = false;
LCOMMDirectiveAlignmentType = LCOMM::ByteAlignment;
HasDotTypeDotSizeDirective = false;
HasSingleParameterDotFile = true;
WeakRefDirective = "\t.weak\t";
AvoidWeakIfComdat = true;
// Doesn't support visibility:
HiddenVisibilityAttr = HiddenDeclarationVisibilityAttr = MCSA_Invalid;
ProtectedVisibilityAttr = MCSA_Invalid;
// Set up DWARF directives
SupportsDebugInformation = true;
NeedsDwarfSectionOffsetDirective = true;
// At least MSVC inline-asm does AShr.
UseLogicalShr = false;
// If this is a COFF target, assume that it supports associative comdats. It's
// part of the spec.
HasCOFFAssociativeComdats = true;
// We can generate constants in comdat sections that can be shared,
// but in order not to create null typed symbols, we actually need to
// make them global symbols as well.
HasCOFFComdatConstants = true;
}
bool MCAsmInfoCOFF::useCodeAlign(const MCSection &Sec) const {
return Sec.isText();
}
void MCAsmInfoMicrosoft::anchor() {}
MCAsmInfoMicrosoft::MCAsmInfoMicrosoft() = default;
void MCAsmInfoGNUCOFF::anchor() {}
MCAsmInfoGNUCOFF::MCAsmInfoGNUCOFF() {
// If this is a GNU environment (mingw or cygwin), don't use associative
// comdats for jump tables, unwind information, and other data associated with
// a function.
HasCOFFAssociativeComdats = false;
// We don't create constants in comdat sections for MinGW.
HasCOFFComdatConstants = false;
}
bool MCSectionCOFF::shouldOmitSectionDirective(StringRef Name) const {
if (COMDATSymbol || isUnique())
return false;
// FIXME: Does .section .bss/.data/.text work everywhere??
if (Name == ".text" || Name == ".data" || Name == ".bss")
return true;
return false;
}
void MCSectionCOFF::setSelection(int Selection) const {
assert(Selection != 0 && "invalid COMDAT selection type");
this->Selection = Selection;
Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT;
}
void MCAsmInfoCOFF::printSwitchToSection(const MCSection &Section, uint32_t,
const Triple &T,
raw_ostream &OS) const {
auto &Sec = static_cast<const MCSectionCOFF &>(Section);
// standard sections don't require the '.section'
if (Sec.shouldOmitSectionDirective(Sec.getName())) {
OS << '\t' << Sec.getName() << '\n';
return;
}
OS << "\t.section\t" << Sec.getName() << ",\"";
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
OS << 'd';
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
OS << 'b';
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_MEM_EXECUTE)
OS << 'x';
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_MEM_WRITE)
OS << 'w';
else if (Sec.getCharacteristics() & COFF::IMAGE_SCN_MEM_READ)
OS << 'r';
else
OS << 'y';
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_LNK_REMOVE)
OS << 'n';
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_MEM_SHARED)
OS << 's';
if ((Sec.getCharacteristics() & COFF::IMAGE_SCN_MEM_DISCARDABLE) &&
!Sec.isImplicitlyDiscardable(Sec.getName()))
OS << 'D';
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_LNK_INFO)
OS << 'i';
OS << '"';
// unique should be tail of .section directive.
if (Sec.isUnique() && !Sec.COMDATSymbol)
OS << ",unique," << Sec.UniqueID;
if (Sec.getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
if (Sec.COMDATSymbol)
OS << ",";
else
OS << "\n\t.linkonce\t";
switch (Sec.Selection) {
case COFF::IMAGE_COMDAT_SELECT_NODUPLICATES:
OS << "one_only";
break;
case COFF::IMAGE_COMDAT_SELECT_ANY:
OS << "discard";
break;
case COFF::IMAGE_COMDAT_SELECT_SAME_SIZE:
OS << "same_size";
break;
case COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH:
OS << "same_contents";
break;
case COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE:
OS << "associative";
break;
case COFF::IMAGE_COMDAT_SELECT_LARGEST:
OS << "largest";
break;
case COFF::IMAGE_COMDAT_SELECT_NEWEST:
OS << "newest";
break;
default:
assert(false && "unsupported COFF selection type");
break;
}
if (Sec.COMDATSymbol) {
OS << ",";
Sec.COMDATSymbol->print(OS, this);
}
}
if (Sec.isUnique() && Sec.COMDATSymbol)
OS << ",unique," << Sec.UniqueID;
OS << '\n';
}
|
