LLVM 17.0.0git
MCObjectStreamer.h
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1//===- MCObjectStreamer.h - MCStreamer 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_MCOBJECTSTREAMER_H
10#define LLVM_MC_MCOBJECTSTREAMER_H
11
12#include "llvm/ADT/SetVector.h"
14#include "llvm/MC/MCFixup.h"
15#include "llvm/MC/MCFragment.h"
16#include "llvm/MC/MCSection.h"
17#include "llvm/MC/MCStreamer.h"
18
19namespace llvm {
20class MCContext;
21class MCInst;
22class MCObjectWriter;
23class MCSymbol;
24struct MCDwarfFrameInfo;
25class MCAssembler;
26class MCCodeEmitter;
27class MCSubtargetInfo;
28class MCExpr;
29class MCFragment;
30class MCDataFragment;
31class MCAsmBackend;
32class raw_ostream;
33class raw_pwrite_stream;
34
35/// Streaming object file generation interface.
36///
37/// This class provides an implementation of the MCStreamer interface which is
38/// suitable for use with the assembler backend. Specific object file formats
39/// are expected to subclass this interface to implement directives specific
40/// to that file format or custom semantics expected by the object writer
41/// implementation.
43 std::unique_ptr<MCAssembler> Assembler;
44 MCSection::iterator CurInsertionPoint;
45 bool EmitEHFrame;
46 bool EmitDebugFrame;
47 SmallVector<MCSymbol *, 2> PendingLabels;
48 SmallSetVector<MCSection *, 4> PendingLabelSections;
49 unsigned CurSubsectionIdx;
50 struct PendingMCFixup {
51 const MCSymbol *Sym;
54 PendingMCFixup(const MCSymbol *McSym, MCDataFragment *F, MCFixup McFixup)
55 : Sym(McSym), Fixup(McFixup), DF(F) {}
56 };
58
59 struct PendingAssignment {
60 MCSymbol *Symbol;
61 const MCExpr *Value;
62 };
63
64 /// A list of conditional assignments we may need to emit if the target
65 /// symbol is later emitted.
67 pendingAssignments;
68
69 virtual void emitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0;
70 void emitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
71 void emitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
72 MCSymbol *emitCFILabel() override;
73 void emitInstructionImpl(const MCInst &Inst, const MCSubtargetInfo &STI);
74 void resolvePendingFixups();
75
76protected:
77 MCObjectStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
78 std::unique_ptr<MCObjectWriter> OW,
79 std::unique_ptr<MCCodeEmitter> Emitter);
81
82public:
83 /// state management
84 void reset() override;
85
86 /// Object streamers require the integrated assembler.
87 bool isIntegratedAssemblerRequired() const override { return true; }
88
89 void emitFrames(MCAsmBackend *MAB);
90 void emitCFISections(bool EH, bool Debug) override;
91
93
96 MCSection *CurSection = getCurrentSectionOnly();
97 CurSection->getFragmentList().insert(CurInsertionPoint, F);
98 F->setParent(CurSection);
99 }
100
101 /// Get a data fragment to write into, creating a new one if the current
102 /// fragment is not a data fragment.
103 /// Optionally a \p STI can be passed in so that a new fragment is created
104 /// if the Subtarget differs from the current fragment.
106
107protected:
108 bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection);
109
110 /// Assign a label to the current Section and Subsection even though a
111 /// fragment is not yet present. Use flushPendingLabels(F) to associate
112 /// a fragment with this label.
113 void addPendingLabel(MCSymbol* label);
114
115 /// If any labels have been emitted but not assigned fragments in the current
116 /// Section and Subsection, ensure that they get assigned, either to fragment
117 /// F if possible or to a new data fragment. Optionally, one can provide an
118 /// offset \p FOffset as a symbol offset within the fragment.
119 void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0);
120
121public:
122 void visitUsedSymbol(const MCSymbol &Sym) override;
123
124 /// Create a data fragment for any pending labels across all Sections
125 /// and Subsections.
126 void flushPendingLabels();
127
128 MCAssembler &getAssembler() { return *Assembler; }
129 MCAssembler *getAssemblerPtr() override;
130 /// \name MCStreamer Interface
131 /// @{
132
133 void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
134 virtual void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F,
136 void emitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
138 const MCExpr *Value) override;
139 void emitValueImpl(const MCExpr *Value, unsigned Size,
140 SMLoc Loc = SMLoc()) override;
141 void emitULEB128Value(const MCExpr *Value) override;
142 void emitSLEB128Value(const MCExpr *Value) override;
143 void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
144 void changeSection(MCSection *Section, const MCExpr *Subsection) override;
145 void emitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
146
147 /// Emit an instruction to a special fragment, because this instruction
148 /// can change its size during relaxation.
149 virtual void emitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
150
151 void emitBundleAlignMode(Align Alignment) override;
152 void emitBundleLock(bool AlignToEnd) override;
153 void emitBundleUnlock() override;
154 void emitBytes(StringRef Data) override;
155 void emitValueToAlignment(Align Alignment, int64_t Value = 0,
156 unsigned ValueSize = 1,
157 unsigned MaxBytesToEmit = 0) override;
158 void emitCodeAlignment(Align ByteAlignment, const MCSubtargetInfo *STI,
159 unsigned MaxBytesToEmit = 0) override;
160 void emitValueToOffset(const MCExpr *Offset, unsigned char Value,
161 SMLoc Loc) override;
162 void emitDwarfLocDirective(unsigned FileNo, unsigned Line, unsigned Column,
163 unsigned Flags, unsigned Isa,
164 unsigned Discriminator,
165 StringRef FileName) override;
166 void emitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
167 const MCSymbol *Label,
168 unsigned PointerSize) override;
169 void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel) override;
170 void emitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
171 const MCSymbol *Label);
172 void emitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line,
173 unsigned Column, bool PrologueEnd, bool IsStmt,
174 StringRef FileName, SMLoc Loc) override;
175 void emitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin,
176 const MCSymbol *End) override;
177 void emitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
178 unsigned SourceFileId,
179 unsigned SourceLineNum,
180 const MCSymbol *FnStartSym,
181 const MCSymbol *FnEndSym) override;
183 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
184 StringRef FixedSizePortion) override;
185 void emitCVStringTableDirective() override;
186 void emitCVFileChecksumsDirective() override;
187 void emitCVFileChecksumOffsetDirective(unsigned FileNo) override;
188 void emitDTPRel32Value(const MCExpr *Value) override;
189 void emitDTPRel64Value(const MCExpr *Value) override;
190 void emitTPRel32Value(const MCExpr *Value) override;
191 void emitTPRel64Value(const MCExpr *Value) override;
192 void emitGPRel32Value(const MCExpr *Value) override;
193 void emitGPRel64Value(const MCExpr *Value) override;
194 std::optional<std::pair<bool, std::string>>
196 SMLoc Loc, const MCSubtargetInfo &STI) override;
198 void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
199 SMLoc Loc = SMLoc()) override;
200 void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
201 SMLoc Loc = SMLoc()) override;
202 void emitNops(int64_t NumBytes, int64_t ControlledNopLength, SMLoc Loc,
203 const MCSubtargetInfo &STI) override;
204 void emitFileDirective(StringRef Filename) override;
205 void emitFileDirective(StringRef Filename, StringRef CompilerVerion,
206 StringRef TimeStamp, StringRef Description) override;
207
208 void emitAddrsig() override;
209 void emitAddrsigSym(const MCSymbol *Sym) override;
210
211 void finishImpl() override;
212
213 /// Emit the absolute difference between two symbols if possible.
214 ///
215 /// Emit the absolute difference between \c Hi and \c Lo, as long as we can
216 /// compute it. Currently, that requires that both symbols are in the same
217 /// data fragment and that the target has not specified that diff expressions
218 /// require relocations to be emitted. Otherwise, do nothing and return
219 /// \c false.
220 ///
221 /// \pre Offset of \c Hi is greater than the offset \c Lo.
222 void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
223 unsigned Size) override;
224
226 const MCSymbol *Lo) override;
227
228 bool mayHaveInstructions(MCSection &Sec) const override;
229
230 /// Emits pending conditional assignments that depend on \p Symbol
231 /// being emitted.
232 void emitPendingAssignments(MCSymbol *Symbol);
233};
234
235} // end namespace llvm
236
237#endif
dxil DXContainer Global Emitter
std::string Name
uint64_t Size
#define F(x, y, z)
Definition: MD5.cpp:55
LLVMContext & Context
PowerPC TLS Dynamic Call Fixup
bool Debug
This file implements a set that has insertion order iteration characteristics.
This file defines the SmallVector class.
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:41
Context object for machine code objects.
Definition: MCContext.h:76
Fragment for data and encoded instructions.
Definition: MCFragment.h:241
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:35
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:71
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
void emitFill(const MCExpr &NumBytes, uint64_t FillValue, SMLoc Loc=SMLoc()) override
Emit Size bytes worth of the value specified by FillValue.
void emitDwarfLineEndEntry(MCSection *Section, MCSymbol *LastLabel) override
Emit the debug line end entry.
void emitValueToAlignment(Align Alignment, int64_t Value=0, unsigned ValueSize=1, unsigned MaxBytesToEmit=0) override
Emit some number of copies of Value until the byte alignment ByteAlignment is reached.
void emitAssignment(MCSymbol *Symbol, const MCExpr *Value) override
Emit an assignment of Value to Symbol.
void emitULEB128Value(const MCExpr *Value) override
void emitSLEB128Value(const MCExpr *Value) override
void emitNops(int64_t NumBytes, int64_t ControlledNopLength, SMLoc Loc, const MCSubtargetInfo &STI) override
MCDataFragment * getOrCreateDataFragment(const MCSubtargetInfo *STI=nullptr)
Get a data fragment to write into, creating a new one if the current fragment is not a data fragment.
void emitCVInlineLinetableDirective(unsigned PrimaryFunctionId, unsigned SourceFileId, unsigned SourceLineNum, const MCSymbol *FnStartSym, const MCSymbol *FnEndSym) override
This implements the CodeView '.cv_inline_linetable' assembler directive.
void emitCVStringTableDirective() override
This implements the CodeView '.cv_stringtable' assembler directive.
void emitBundleAlignMode(Align Alignment) override
Set the bundle alignment mode from now on in the section.
MCAssembler & getAssembler()
void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override
Emit an weak reference from Alias to Symbol.
void emitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, const MCSymbol *Label, unsigned PointerSize) override
If targets does not support representing debug line section by .loc/.file directives in assembly outp...
void emitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, const MCSymbol *Label)
void emitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line, unsigned Column, bool PrologueEnd, bool IsStmt, StringRef FileName, SMLoc Loc) override
This implements the CodeView '.cv_loc' assembler directive.
void emitDTPRel32Value(const MCExpr *Value) override
Emit the expression Value into the output as a dtprel (32-bit DTP relative) value.
void emitBytes(StringRef Data) override
Emit the bytes in Data into the output.
void emitBundleLock(bool AlignToEnd) override
The following instructions are a bundle-locked group.
void emitPendingAssignments(MCSymbol *Symbol)
Emits pending conditional assignments that depend on Symbol being emitted.
void emitFileDirective(StringRef Filename) override
Switch to a new logical file.
void emitCVDefRangeDirective(ArrayRef< std::pair< const MCSymbol *, const MCSymbol * > > Ranges, StringRef FixedSizePortion) override
This implements the CodeView '.cv_def_range' assembler directive.
void emitGPRel64Value(const MCExpr *Value) override
Emit the expression Value into the output as a gprel64 (64-bit GP relative) value.
MCAssembler * getAssemblerPtr() override
void flushPendingLabels()
Create a data fragment for any pending labels across all Sections and Subsections.
virtual void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F, uint64_t Offset)
std::optional< std::pair< bool, std::string > > emitRelocDirective(const MCExpr &Offset, StringRef Name, const MCExpr *Expr, SMLoc Loc, const MCSubtargetInfo &STI) override
Record a relocation described by the .reloc directive.
void emitAddrsigSym(const MCSymbol *Sym) override
bool isIntegratedAssemblerRequired() const override
Object streamers require the integrated assembler.
void emitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override
Emit the given Instruction into the current section.
void visitUsedSymbol(const MCSymbol &Sym) override
void emitGPRel32Value(const MCExpr *Value) override
Emit the expression Value into the output as a gprel32 (32-bit GP relative) value.
void insert(MCFragment *F)
virtual void emitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &)
Emit an instruction to a special fragment, because this instruction can change its size during relaxa...
void emitLabel(MCSymbol *Symbol, SMLoc Loc=SMLoc()) override
Emit a label for Symbol into the current section.
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 finishImpl() override
Streamer specific finalization.
void emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi, const MCSymbol *Lo) override
Emit the absolute difference between two symbols encoded with ULEB128.
void emitBundleUnlock() override
Ends a bundle-locked group.
bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection)
void emitCFISections(bool EH, bool Debug) override
void emitDwarfLocDirective(unsigned FileNo, unsigned Line, unsigned Column, unsigned Flags, unsigned Isa, unsigned Discriminator, StringRef FileName) override
This implements the DWARF2 '.loc fileno lineno ...' assembler directive.
void addPendingLabel(MCSymbol *label)
Assign a label to the current Section and Subsection even though a fragment is not yet present.
bool mayHaveInstructions(MCSection &Sec) const override
MCFragment * getCurrentFragment() const
void emitCodeAlignment(Align ByteAlignment, const MCSubtargetInfo *STI, unsigned MaxBytesToEmit=0) override
Emit nops until the byte alignment ByteAlignment is reached.
void emitFrames(MCAsmBackend *MAB)
void changeSection(MCSection *Section, const MCExpr *Subsection) override
Update streamer for a new active section.
void emitTPRel64Value(const MCExpr *Value) override
Emit the expression Value into the output as a tprel (64-bit TP relative) value.
void emitCVFileChecksumOffsetDirective(unsigned FileNo) override
This implements the CodeView '.cv_filechecksumoffset' assembler directive.
void emitTPRel32Value(const MCExpr *Value) override
Emit the expression Value into the output as a tprel (32-bit TP relative) value.
void emitConditionalAssignment(MCSymbol *Symbol, const MCExpr *Value) override
Emit an assignment of Value to Symbol, but only if Value is also emitted.
void emitCVFileChecksumsDirective() override
This implements the CodeView '.cv_filechecksums' assembler directive.
void emitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin, const MCSymbol *End) override
This implements the CodeView '.cv_linetable' assembler directive.
void emitDTPRel64Value(const MCExpr *Value) override
Emit the expression Value into the output as a dtprel (64-bit DTP relative) value.
void emitValueToOffset(const MCExpr *Offset, unsigned char Value, SMLoc Loc) override
Emit some number of copies of Value until the byte offset Offset is reached.
void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo, unsigned Size) override
Emit the absolute difference between two symbols if possible.
Instances of this class represent a uniqued identifier for a section in the current translation unit.
Definition: MCSection.h:39
MCSection::FragmentListType & getFragmentList()
Definition: MCSection.h:172
FragmentListType::iterator iterator
Definition: MCSection.h:64
Streaming machine code generation interface.
Definition: MCStreamer.h:212
MCSection * getCurrentSectionOnly() const
Definition: MCStreamer.h:393
void emitFill(uint64_t NumBytes, uint8_t FillValue)
Emit NumBytes bytes worth of the value specified by FillValue.
Definition: MCStreamer.cpp:221
Generic base class for all target subtargets.
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
A SetVector that performs no allocations if smaller than a certain size.
Definition: SetVector.h:301
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1200
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
LLVM Value Representation.
Definition: Value.h:74
iterator insert(iterator where, pointer New)
Definition: ilist.h:229
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:406
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39