LLVM 20.0.0git
MCELFStreamer.h
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1//===- MCELFStreamer.h - MCStreamer ELF Object File Interface ---*- 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_MCELFSTREAMER_H
10#define LLVM_MC_MCELFSTREAMER_H
11
16
17namespace llvm {
18
19class MCContext;
20class MCDataFragment;
21class MCFragment;
22class MCObjectWriter;
23class MCSection;
24class MCSubtargetInfo;
25class MCSymbol;
26class MCSymbolRefExpr;
27class MCAsmBackend;
28class MCCodeEmitter;
29class MCExpr;
30class MCInst;
31
33public:
34 MCELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
35 std::unique_ptr<MCObjectWriter> OW,
36 std::unique_ptr<MCCodeEmitter> Emitter);
37
38 ~MCELFStreamer() override = default;
39
40 /// state management
41 void reset() override {
42 SeenIdent = false;
44 }
45
47
48 /// \name MCStreamer Interface
49 /// @{
50
51 void initSections(bool NoExecStack, const MCSubtargetInfo &STI) override;
52 void changeSection(MCSection *Section, uint32_t Subsection = 0) override;
53 void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
54 void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCDataFragment &F,
55 uint64_t Offset) override;
56 void emitAssemblerFlag(MCAssemblerFlag Flag) override;
57 void emitThumbFunc(MCSymbol *Func) override;
58 void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
59 bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
60 void emitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;
62 Align ByteAlignment) override;
63
64 void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
65 void emitELFSymverDirective(const MCSymbol *OriginalSym, StringRef Name,
66 bool KeepOriginalSym) override;
67
69 Align ByteAlignment) override;
70
71 void emitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
72 uint64_t Size = 0, Align ByteAlignment = Align(1),
73 SMLoc L = SMLoc()) override;
74 void emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
75 Align ByteAlignment = Align(1)) override;
76 void emitValueImpl(const MCExpr *Value, unsigned Size,
77 SMLoc Loc = SMLoc()) override;
78
79 void emitIdent(StringRef IdentString) override;
80
81 void emitValueToAlignment(Align, int64_t, unsigned, unsigned) override;
82
84 const MCSymbolRefExpr *To, uint64_t Count) override;
85
86 // This is final. Override MCTargetStreamer::finish instead for
87 // target-specific code.
88 void finishImpl() final;
89
90 void emitBundleAlignMode(Align Alignment) override;
91 void emitBundleLock(bool AlignToEnd) override;
92 void emitBundleUnlock() override;
93
94 /// ELF object attributes section emission support
96 // This structure holds all attributes, accounting for their string /
97 // numeric value, so we can later emit them in declaration order, keeping
98 // all in the same vector.
99 enum {
100 HiddenAttribute = 0,
103 NumericAndTextAttributes
105 unsigned Tag;
106 unsigned IntValue;
107 std::string StringValue;
108 };
109
110 // Attributes that are added and managed entirely by target.
112 void setAttributeItem(unsigned Attribute, unsigned Value,
113 bool OverwriteExisting);
115 bool OverwriteExisting);
116 void setAttributeItems(unsigned Attribute, unsigned IntValue,
117 StringRef StringValue, bool OverwriteExisting);
118 void emitAttributesSection(StringRef Vendor, const Twine &Section,
119 unsigned Type, MCSection *&AttributeSection) {
120 createAttributesSection(Vendor, Section, Type, AttributeSection, Contents);
121 }
122
123private:
124 AttributeItem *getAttributeItem(unsigned Attribute);
125 size_t calculateContentSize(SmallVector<AttributeItem, 64> &AttrsVec);
126 void createAttributesSection(StringRef Vendor, const Twine &Section,
127 unsigned Type, MCSection *&AttributeSection,
129
130 // GNU attributes that will get emitted at the end of the asm file.
131 SmallVector<AttributeItem, 64> GNUAttributes;
132
133public:
134 void emitGNUAttribute(unsigned Tag, unsigned Value) override {
136 std::string(StringRef(""))};
137 GNUAttributes.push_back(Item);
138 }
139
140private:
141 bool isBundleLocked() const;
142 void emitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &) override;
143 void emitInstToData(const MCInst &Inst, const MCSubtargetInfo &) override;
144
145 void fixSymbolsInTLSFixups(const MCExpr *expr);
146 void finalizeCGProfileEntry(const MCSymbolRefExpr *&S, uint64_t Offset);
147 void finalizeCGProfile();
148
149 bool SeenIdent = false;
150};
151
152MCELFStreamer *createARMELFStreamer(MCContext &Context,
153 std::unique_ptr<MCAsmBackend> TAB,
154 std::unique_ptr<MCObjectWriter> OW,
155 std::unique_ptr<MCCodeEmitter> Emitter,
156 bool IsThumb, bool IsAndroid);
157
158} // end namespace llvm
159
160#endif // LLVM_MC_MCELFSTREAMER_H
BlockVerifier::State From
dxil DXContainer Global Emitter
std::string Name
uint64_t Size
#define F(x, y, z)
Definition: MD5.cpp:55
This file defines the SmallVector class.
Context object for machine code objects.
Definition: MCContext.h:83
Fragment for data and encoded instructions.
Definition: MCFragment.h:231
void emitBundleLock(bool AlignToEnd) override
The following instructions are a bundle-locked group.
SmallVector< AttributeItem, 64 > Contents
void emitAttributesSection(StringRef Vendor, const Twine &Section, unsigned Type, MCSection *&AttributeSection)
void emitValueToAlignment(Align, int64_t, unsigned, unsigned) override
Emit some number of copies of Value until the byte alignment ByteAlignment is reached.
void changeSection(MCSection *Section, uint32_t Subsection=0) override
This is called by popSection and switchSection, if the current section changes.
void emitIdent(StringRef IdentString) override
Emit the "identifiers" directive.
void setAttributeItems(unsigned Attribute, unsigned IntValue, StringRef StringValue, bool OverwriteExisting)
void emitBundleUnlock() override
Ends a bundle-locked group.
void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size, Align ByteAlignment) override
Emit a common symbol.
void emitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc=SMLoc()) override
Emit the expression Value into the output as a native integer of the given Size bytes.
void emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size, Align ByteAlignment) override
Emit a local common (.lcomm) symbol.
void emitAssemblerFlag(MCAssemblerFlag Flag) override
Note in the output the specified Flag.
void emitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override
Set the DescValue for the Symbol.
void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override
Emit an ELF .size directive.
void emitThumbFunc(MCSymbol *Func) override
Note in the output that the specified Func is a Thumb mode function (ARM target only).
void emitELFSymverDirective(const MCSymbol *OriginalSym, StringRef Name, bool KeepOriginalSym) override
Emit an ELF .symver directive.
~MCELFStreamer() override=default
void emitCGProfileEntry(const MCSymbolRefExpr *From, const MCSymbolRefExpr *To, uint64_t Count) override
ELFObjectWriter & getWriter()
void emitGNUAttribute(unsigned Tag, unsigned Value) override
Emit a .gnu_attribute directive.
void emitZerofill(MCSection *Section, MCSymbol *Symbol=nullptr, uint64_t Size=0, Align ByteAlignment=Align(1), SMLoc L=SMLoc()) override
Emit the zerofill section and an optional symbol.
void setAttributeItem(unsigned Attribute, unsigned Value, bool OverwriteExisting)
void finishImpl() final
Streamer specific finalization.
void reset() override
state management
Definition: MCELFStreamer.h:41
void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override
Emit an weak reference from Alias to Symbol.
void emitLabel(MCSymbol *Symbol, SMLoc Loc=SMLoc()) override
Emit a label for Symbol into the current section.
void emitBundleAlignMode(Align Alignment) override
Set the bundle alignment mode from now on in the section.
bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override
Add the given Attribute to Symbol.
void emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size, Align ByteAlignment=Align(1)) override
Emit a thread local bss (.tbss) symbol.
void initSections(bool NoExecStack, const MCSubtargetInfo &STI) override
Create the default sections and set the initial one.
void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCDataFragment &F, uint64_t Offset) override
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:34
Instances of this class represent a single low-level machine instruction.
Definition: MCInst.h:184
Streaming object file generation interface.
void reset() override
state management
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:36
Generic base class for all target subtargets.
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:188
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
Represents a location in source code.
Definition: SMLoc.h:23
void push_back(const T &Elt)
Definition: SmallVector.h:426
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1209
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
LLVM Value Representation.
Definition: Value.h:74
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:480
MCELFStreamer * createARMELFStreamer(MCContext &Context, std::unique_ptr< MCAsmBackend > TAB, std::unique_ptr< MCObjectWriter > OW, std::unique_ptr< MCCodeEmitter > Emitter, bool IsThumb, bool IsAndroid)
MCAssemblerFlag
Definition: MCDirectives.h:53
MCSymbolAttr
Definition: MCDirectives.h:18
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
ELF object attributes section emission support.
Definition: MCELFStreamer.h:95