LLVM 19.0.0git
MCELFStreamer.h
Go to the documentation of this file.
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
15
16namespace llvm {
17
18class MCContext;
19class MCDataFragment;
20class MCFragment;
21class MCObjectWriter;
22class MCSection;
23class MCSubtargetInfo;
24class MCSymbol;
25class MCSymbolRefExpr;
26class MCAsmBackend;
27class MCCodeEmitter;
28class MCExpr;
29class MCInst;
30
32public:
33 MCELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
34 std::unique_ptr<MCObjectWriter> OW,
35 std::unique_ptr<MCCodeEmitter> Emitter);
36
37 ~MCELFStreamer() override = default;
38
39 /// state management
40 void reset() override {
41 SeenIdent = false;
42 BundleGroups.clear();
44 }
45
46 /// \name MCStreamer Interface
47 /// @{
48
49 void initSections(bool NoExecStack, const MCSubtargetInfo &STI) override;
50 void changeSection(MCSection *Section, const MCExpr *Subsection) override;
51 void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
52 void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F,
53 uint64_t Offset) override;
54 void emitAssemblerFlag(MCAssemblerFlag Flag) override;
55 void emitThumbFunc(MCSymbol *Func) override;
56 void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
57 bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
58 void emitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;
60 Align ByteAlignment) override;
61
62 void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
63 void emitELFSymverDirective(const MCSymbol *OriginalSym, StringRef Name,
64 bool KeepOriginalSym) override;
65
67 Align ByteAlignment) override;
68
69 void emitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
70 uint64_t Size = 0, Align ByteAlignment = Align(1),
71 SMLoc L = SMLoc()) override;
72 void emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
73 Align ByteAlignment = Align(1)) override;
74 void emitValueImpl(const MCExpr *Value, unsigned Size,
75 SMLoc Loc = SMLoc()) override;
76
77 void emitIdent(StringRef IdentString) override;
78
79 void emitValueToAlignment(Align, int64_t, unsigned, unsigned) override;
80
82 const MCSymbolRefExpr *To, uint64_t Count) override;
83
84 void finishImpl() override;
85
86 void emitBundleAlignMode(Align Alignment) override;
87 void emitBundleLock(bool AlignToEnd) override;
88 void emitBundleUnlock() override;
89
90 /// ELF object attributes section emission support
92 // This structure holds all attributes, accounting for their string /
93 // numeric value, so we can later emit them in declaration order, keeping
94 // all in the same vector.
95 enum {
101 unsigned Tag;
102 unsigned IntValue;
103 std::string StringValue;
104 };
105
106 // Attributes that are added and managed entirely by target.
108 void setAttributeItem(unsigned Attribute, unsigned Value,
109 bool OverwriteExisting);
111 bool OverwriteExisting);
112 void setAttributeItems(unsigned Attribute, unsigned IntValue,
113 StringRef StringValue, bool OverwriteExisting);
114 void emitAttributesSection(StringRef Vendor, const Twine &Section,
115 unsigned Type, MCSection *&AttributeSection) {
116 createAttributesSection(Vendor, Section, Type, AttributeSection, Contents);
117 }
118
119private:
120 AttributeItem *getAttributeItem(unsigned Attribute);
121 size_t calculateContentSize(SmallVector<AttributeItem, 64> &AttrsVec);
122 void createAttributesSection(StringRef Vendor, const Twine &Section,
123 unsigned Type, MCSection *&AttributeSection,
125
126 // GNU attributes that will get emitted at the end of the asm file.
127 SmallVector<AttributeItem, 64> GNUAttributes;
128
129public:
130 void emitGNUAttribute(unsigned Tag, unsigned Value) override {
132 std::string(StringRef(""))};
133 GNUAttributes.push_back(Item);
134 }
135
136private:
137 bool isBundleLocked() const;
138 void emitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &) override;
139 void emitInstToData(const MCInst &Inst, const MCSubtargetInfo &) override;
140
141 void fixSymbolsInTLSFixups(const MCExpr *expr);
142 void finalizeCGProfileEntry(const MCSymbolRefExpr *&S, uint64_t Offset);
143 void finalizeCGProfile();
144
145 /// Merge the content of the fragment \p EF into the fragment \p DF.
146 void mergeFragment(MCDataFragment *, MCDataFragment *);
147
148 bool SeenIdent = false;
149
150 /// BundleGroups - The stack of fragments holding the bundle-locked
151 /// instructions.
153};
154
155MCELFStreamer *createARMELFStreamer(MCContext &Context,
156 std::unique_ptr<MCAsmBackend> TAB,
157 std::unique_ptr<MCObjectWriter> OW,
158 std::unique_ptr<MCCodeEmitter> Emitter,
159 bool RelaxAll, bool IsThumb, bool IsAndroid);
160
161} // end namespace llvm
162
163#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
LLVMContext & Context
This file defines the SmallVector class.
Context object for machine code objects.
Definition: MCContext.h:76
Fragment for data and encoded instructions.
Definition: MCFragment.h:242
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 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 emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F, uint64_t Offset) override
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
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 reset() override
state management
Definition: MCELFStreamer.h:40
void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override
Emit an weak reference from Alias to Symbol.
void changeSection(MCSection *Section, const MCExpr *Subsection) override
Update streamer for a new active section.
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 finishImpl() override
Streamer specific finalization.
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
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:39
Generic base class for all target subtargets.
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:192
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
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:456
MCELFStreamer * createARMELFStreamer(MCContext &Context, std::unique_ptr< MCAsmBackend > TAB, std::unique_ptr< MCObjectWriter > OW, std::unique_ptr< MCCodeEmitter > Emitter, bool RelaxAll, 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:91
enum llvm::MCELFStreamer::AttributeItem::@328 Type