//===- MCStreamer.h - High-level Streaming Machine Code Output --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the MCStreamer class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCSTREAMER_H
#define LLVM_MC_MCSTREAMER_H
#include "llvm/Support/DataTypes.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCWin64EH.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
namespace llvm {
class MCAsmBackend;
class MCAsmInfo;
class MCCodeEmitter;
class MCContext;
class MCExpr;
class MCInst;
class MCInstPrinter;
class MCSection;
class MCSymbol;
class StringRef;
class TargetLoweringObjectFile;
class Twine;
class raw_ostream;
class formatted_raw_ostream;
/// MCStreamer - Streaming machine code generation interface. This interface
/// is intended to provide a programatic interface that is very similar to the
/// level that an assembler .s file provides. It has callbacks to emit bytes,
/// handle directives, etc. The implementation of this interface retains
/// state to know what the current section is etc.
///
/// There are multiple implementations of this interface: one for writing out
/// a .s file, and implementations that write out .o files of various formats.
///
class MCStreamer {
MCContext &Context;
MCStreamer(const MCStreamer&); // DO NOT IMPLEMENT
MCStreamer &operator=(const MCStreamer&); // DO NOT IMPLEMENT
bool EmitEHFrame;
bool EmitDebugFrame;
std::vector<MCDwarfFrameInfo> FrameInfos;
MCDwarfFrameInfo *getCurrentFrameInfo();
void EnsureValidFrame();
std::vector<MCWin64EHUnwindInfo *> W64UnwindInfos;
MCWin64EHUnwindInfo *CurrentW64UnwindInfo;
void setCurrentW64UnwindInfo(MCWin64EHUnwindInfo *Frame);
void EnsureValidW64UnwindInfo();
MCSymbol* LastSymbol;
/// SectionStack - This is stack of current and previous section
/// values saved by PushSection.
SmallVector<std::pair<const MCSection *,
const MCSection *>, 4> SectionStack;
unsigned UniqueCodeBeginSuffix;
unsigned UniqueDataBeginSuffix;
protected:
/// Indicator of whether the previous data-or-code indicator was for
/// code or not. Used to determine when we need to emit a new indicator.
enum DataType {
Data,
Code,
JumpTable8,
JumpTable16,
JumpTable32
};
DataType RegionIndicator;
MCStreamer(MCContext &Ctx);
const MCExpr *BuildSymbolDiff(MCContext &Context, const MCSymbol *A,
const MCSymbol *B);
const MCExpr *ForceExpAbs(const MCExpr* Expr);
void EmitFrames(bool usingCFI);
MCWin64EHUnwindInfo *getCurrentW64UnwindInfo(){return CurrentW64UnwindInfo;}
void EmitW64Tables();
public:
virtual ~MCStreamer();
MCContext &getContext() const { return Context; }
unsigned getNumFrameInfos() {
return FrameInfos.size();
}
const MCDwarfFrameInfo &getFrameInfo(unsigned i) {
return FrameInfos[i];
}
ArrayRef<MCDwarfFrameInfo> getFrameInfos() {
return FrameInfos;
}
unsigned getNumW64UnwindInfos() {
return W64UnwindInfos.size();
}
MCWin64EHUnwindInfo &getW64UnwindInfo(unsigned i) {
return *W64UnwindInfos[i];
}
/// @name Assembly File Formatting.
/// @{
/// isVerboseAsm - Return true if this streamer supports verbose assembly
/// and if it is enabled.
virtual bool isVerboseAsm() const { return false; }
/// hasRawTextSupport - Return true if this asm streamer supports emitting
/// unformatted text to the .s file with EmitRawText.
virtual bool hasRawTextSupport() const { return false; }
/// AddComment - Add a comment that can be emitted to the generated .s
/// file if applicable as a QoI issue to make the output of the compiler
/// more readable. This only affects the MCAsmStreamer, and only when
/// verbose assembly output is enabled.
///
/// If the comment includes embedded \n's, they will each get the comment
/// prefix as appropriate. The added comment should not end with a \n.
virtual void AddComment(const Twine &T) {}
/// GetCommentOS - Return a raw_ostream that comments can be written to.
/// Unlike AddComment, you are required to terminate comments with \n if you
/// use this method.
virtual raw_ostream &GetCommentOS();
/// AddBlankLine - Emit a blank line to a .s file to pretty it up.
virtual void AddBlankLine() {}
/// @}
/// @name Symbol & Section Management
/// @{
/// getCurrentSection - Return the current section that the streamer is
/// emitting code to.
const MCSection *getCurrentSection() const {
if (!SectionStack.empty())
return SectionStack.back().first;
return NULL;
}
/// getPreviousSection - Return the previous section that the streamer is
/// emitting code to.
const MCSection *getPreviousSection() const {
if (!SectionStack.empty())
return SectionStack.back().second;
return NULL;
}
/// ChangeSection - Update streamer for a new active section.
///
/// This is called by PopSection and SwitchSection, if the current
/// section changes.
virtual void ChangeSection(const MCSection *) = 0;
/// pushSection - Save the current and previous section on the
/// section stack.
void PushSection() {
SectionStack.push_back(std::make_pair(getCurrentSection(),
getPreviousSection()));
}
/// popSection - Restore the current and previous section from
/// the section stack. Calls ChangeSection as needed.
///
/// Returns false if the stack was empty.
bool PopSection() {
if (SectionStack.size() <= 1)
return false;
const MCSection *oldSection = SectionStack.pop_back_val().first;
const MCSection *curSection = SectionStack.back().first;
if (oldSection != curSection)
ChangeSection(curSection);
return true;
}
/// SwitchSection - Set the current section where code is being emitted to
/// @p Section. This is required to update CurSection.
///
/// This corresponds to assembler directives like .section, .text, etc.
void SwitchSection(const MCSection *Section) {
assert(Section && "Cannot switch to a null section!");
const MCSection *curSection = SectionStack.back().first;
SectionStack.back().second = curSection;
if (Section != curSection) {
SectionStack.back().first = Section;
ChangeSection(Section);
}
}
/// SwitchSectionNoChange - Set the current section where code is being
/// emitted to @p Section. This is required to update CurSection. This
/// version does not call ChangeSection.
void SwitchSectionNoChange(const MCSection *Section) {
assert(Section && "Cannot switch to a null section!");
const MCSection *curSection = SectionStack.back().first;
SectionStack.back().second = curSection;
if (Section != curSection)
SectionStack.back().first = Section;
}
/// InitSections - Create the default sections and set the initial one.
virtual void InitSections() = 0;
/// EmitLabel - Emit a label for @p Symbol into the current section.
///
/// This corresponds to an assembler statement such as:
/// foo:
///
/// @param Symbol - The symbol to emit. A given symbol should only be
/// emitted as a label once, and symbols emitted as a label should never be
/// used in an assignment.
virtual void EmitLabel(MCSymbol *Symbol);
/// EmitDataRegion - Emit a label that marks the beginning of a data
/// region.
/// On ELF targets, this corresponds to an assembler statement such as:
/// $d.1:
virtual void EmitDataRegion();
/// EmitJumpTable8Region - Emit a label that marks the beginning of a
/// jump table composed of 8-bit offsets.
/// On ELF targets, this corresponds to an assembler statement such as:
/// $d.1:
virtual void EmitJumpTable8Region();
/// EmitJumpTable16Region - Emit a label that marks the beginning of a
/// jump table composed of 16-bit offsets.
/// On ELF targets, this corresponds to an assembler statement such as:
/// $d.1:
virtual void EmitJumpTable16Region();
/// EmitJumpTable32Region - Emit a label that marks the beginning of a
/// jump table composed of 32-bit offsets.
/// On ELF targets, this corresponds to an assembler statement such as:
/// $d.1:
virtual void EmitJumpTable32Region();
/// EmitCodeRegion - Emit a label that marks the beginning of a code
/// region.
/// On ELF targets, this corresponds to an assembler statement such as:
/// $a.1:
virtual void EmitCodeRegion();
/// ForceCodeRegion - Forcibly sets the current region mode to code. Used
/// at function entry points.
void ForceCodeRegion() { RegionIndicator = Code; }
virtual void EmitEHSymAttributes(const MCSymbol *Symbol,
MCSymbol *EHSymbol);
/// EmitAssemblerFlag - Note in the output the specified @p Flag
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 0;
/// EmitThumbFunc - Note in the output that the specified @p Func is
/// a Thumb mode function (ARM target only).
virtual void EmitThumbFunc(MCSymbol *Func) = 0;
/// EmitAssignment - Emit an assignment of @p Value to @p Symbol.
///
/// This corresponds to an assembler statement such as:
/// symbol = value
///
/// The assignment generates no code, but has the side effect of binding the
/// value in the current context. For the assembly streamer, this prints the
/// binding into the .s file.
///
/// @param Symbol - The symbol being assigned to.
/// @param Value - The value for the symbol.
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) = 0;
/// EmitWeakReference - Emit an weak reference from @p Alias to @p Symbol.
///
/// This corresponds to an assembler statement such as:
/// .weakref alias, symbol
///
/// @param Alias - The alias that is being created.
/// @param Symbol - The symbol being aliased.
virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) = 0;
/// EmitSymbolAttribute - Add the given @p Attribute to @p Symbol.
virtual void EmitSymbolAttribute(MCSymbol *Symbol,
MCSymbolAttr Attribute) = 0;
/// EmitSymbolDesc - Set the @p DescValue for the @p Symbol.
///
/// @param Symbol - The symbol to have its n_desc field set.
/// @param DescValue - The value to set into the n_desc field.
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) = 0;
/// BeginCOFFSymbolDef - Start emitting COFF symbol definition
///
/// @param Symbol - The symbol to have its External & Type fields set.
virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) = 0;
/// EmitCOFFSymbolStorageClass - Emit the storage class of the symbol.
///
/// @param StorageClass - The storage class the symbol should have.
virtual void EmitCOFFSymbolStorageClass(int StorageClass) = 0;
/// EmitCOFFSymbolType - Emit the type of the symbol.
///
/// @param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
virtual void EmitCOFFSymbolType(int Type) = 0;
/// EndCOFFSymbolDef - Marks the end of the symbol definition.
virtual void EndCOFFSymbolDef() = 0;
/// EmitELFSize - Emit an ELF .size directive.
///
/// This corresponds to an assembler statement such as:
/// .size symbol, expression
///
virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) = 0;
/// EmitCommonSymbol - Emit a common symbol.
///
/// @param Symbol - The common symbol to emit.
/// @param Size - The size of the common symbol.
/// @param ByteAlignment - The alignment of the symbol if
/// non-zero. This must be a power of 2.
virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) = 0;
/// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
///
/// @param Symbol - The common symbol to emit.
/// @param Size - The size of the common symbol.
/// @param ByteAlignment - The alignment of the common symbol in bytes.
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) = 0;
/// EmitZerofill - Emit the zerofill section and an optional symbol.
///
/// @param Section - The zerofill section to create and or to put the symbol
/// @param Symbol - The zerofill symbol to emit, if non-NULL.
/// @param Size - The size of the zerofill symbol.
/// @param ByteAlignment - The alignment of the zerofill symbol if
/// non-zero. This must be a power of 2 on some targets.
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
unsigned Size = 0,unsigned ByteAlignment = 0) = 0;
/// EmitTBSSSymbol - Emit a thread local bss (.tbss) symbol.
///
/// @param Section - The thread local common section.
/// @param Symbol - The thread local common symbol to emit.
/// @param Size - The size of the symbol.
/// @param ByteAlignment - The alignment of the thread local common symbol
/// if non-zero. This must be a power of 2 on some targets.
virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment = 0) = 0;
/// @}
/// @name Generating Data
/// @{
/// EmitBytes - Emit the bytes in \arg Data into the output.
///
/// This is used to implement assembler directives such as .byte, .ascii,
/// etc.
virtual void EmitBytes(StringRef Data, unsigned AddrSpace) = 0;
/// EmitValue - Emit the expression @p Value into the output as a native
/// integer of the given @p Size bytes.
///
/// This is used to implement assembler directives such as .word, .quad,
/// etc.
///
/// @param Value - The value to emit.
/// @param Size - The size of the integer (in bytes) to emit. This must
/// match a native machine width.
virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
unsigned AddrSpace) = 0;
void EmitValue(const MCExpr *Value, unsigned Size, unsigned AddrSpace = 0);
/// EmitIntValue - Special case of EmitValue that avoids the client having
/// to pass in a MCExpr for constant integers.
virtual void EmitIntValue(uint64_t Value, unsigned Size,
unsigned AddrSpace = 0);
/// EmitAbsValue - Emit the Value, but try to avoid relocations. On MachO
/// this is done by producing
/// foo = value
/// .long foo
void EmitAbsValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace = 0);
virtual void EmitULEB128Value(const MCExpr *Value) = 0;
virtual void EmitSLEB128Value(const MCExpr *Value) = 0;
/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
/// client having to pass in a MCExpr for constant integers.
void EmitULEB128IntValue(uint64_t Value, unsigned AddrSpace = 0);
/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
/// client having to pass in a MCExpr for constant integers.
void EmitSLEB128IntValue(int64_t Value, unsigned AddrSpace = 0);
/// EmitSymbolValue - Special case of EmitValue that avoids the client
/// having to pass in a MCExpr for MCSymbols.
void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
unsigned AddrSpace = 0);
/// EmitGPRel32Value - Emit the expression @p Value into the output as a
/// gprel32 (32-bit GP relative) value.
///
/// This is used to implement assembler directives such as .gprel32 on
/// targets that support them.
virtual void EmitGPRel32Value(const MCExpr *Value);
/// EmitFill - Emit NumBytes bytes worth of the value specified by
/// FillValue. This implements directives such as '.space'.
virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
unsigned AddrSpace);
/// EmitZeros - Emit NumBytes worth of zeros. This is a convenience
/// function that just wraps EmitFill.
void EmitZeros(uint64_t NumBytes, unsigned AddrSpace) {
EmitFill(NumBytes, 0, AddrSpace);
}
/// EmitValueToAlignment - Emit some number of copies of @p Value until
/// the byte alignment @p ByteAlignment is reached.
///
/// If the number of bytes need to emit for the alignment is not a multiple
/// of @p ValueSize, then the contents of the emitted fill bytes is
/// undefined.
///
/// This used to implement the .align assembler directive.
///
/// @param ByteAlignment - The alignment to reach. This must be a power of
/// two on some targets.
/// @param Value - The value to use when filling bytes.
/// @param ValueSize - The size of the integer (in bytes) to emit for
/// @p Value. This must match a native machine width.
/// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
/// the alignment cannot be reached in this many bytes, no bytes are
/// emitted.
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0) = 0;
/// EmitCodeAlignment - Emit nops until the byte alignment @p ByteAlignment
/// is reached.
///
/// This used to align code where the alignment bytes may be executed. This
/// can emit different bytes for different sizes to optimize execution.
///
/// @param ByteAlignment - The alignment to reach. This must be a power of
/// two on some targets.
/// @param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
/// the alignment cannot be reached in this many bytes, no bytes are
/// emitted.
virtual void EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit = 0) = 0;
/// EmitValueToOffset - Emit some number of copies of @p Value until the
/// byte offset @p Offset is reached.
///
/// This is used to implement assembler directives such as .org.
///
/// @param Offset - The offset to reach. This may be an expression, but the
/// expression must be associated with the current section.
/// @param Value - The value to use when filling bytes.
virtual void EmitValueToOffset(const MCExpr *Offset,
unsigned char Value = 0) = 0;
/// @}
/// EmitFileDirective - Switch to a new logical file. This is used to
/// implement the '.file "foo.c"' assembler directive.
virtual void EmitFileDirective(StringRef Filename) = 0;
/// EmitDwarfFileDirective - Associate a filename with a specified logical
/// file number. This implements the DWARF2 '.file 4 "foo.c"' assembler
/// directive.
virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
/// EmitDwarfLocDirective - This implements the DWARF2
// '.loc fileno lineno ...' assembler directive.
virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
unsigned Column, unsigned Flags,
unsigned Isa,
unsigned Discriminator,
StringRef FileName);
virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
const MCSymbol *LastLabel,
const MCSymbol *Label,
unsigned PointerSize) = 0;
virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
const MCSymbol *Label) {
}
void EmitDwarfSetLineAddr(int64_t LineDelta, const MCSymbol *Label,
int PointerSize);
virtual void EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding);
virtual void EmitCFISections(bool EH, bool Debug);
virtual void EmitCFIStartProc();
virtual void EmitCFIEndProc();
virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
virtual void EmitCFIDefCfaOffset(int64_t Offset);
virtual void EmitCFIDefCfaRegister(int64_t Register);
virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
virtual void EmitCFIRememberState();
virtual void EmitCFIRestoreState();
virtual void EmitCFISameValue(int64_t Register);
virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
virtual void EmitWin64EHStartProc(const MCSymbol *Symbol);
virtual void EmitWin64EHEndProc();
virtual void EmitWin64EHStartChained();
virtual void EmitWin64EHEndChained();
virtual void EmitWin64EHHandler(const MCSymbol *Sym, bool Unwind,
bool Except);
virtual void EmitWin64EHHandlerData();
virtual void EmitWin64EHPushReg(unsigned Register);
virtual void EmitWin64EHSetFrame(unsigned Register, unsigned Offset);
virtual void EmitWin64EHAllocStack(unsigned Size);
virtual void EmitWin64EHSaveReg(unsigned Register, unsigned Offset);
virtual void EmitWin64EHSaveXMM(unsigned Register, unsigned Offset);
virtual void EmitWin64EHPushFrame(bool Code);
virtual void EmitWin64EHEndProlog();
/// EmitInstruction - Emit the given @p Instruction into the current
/// section.
virtual void EmitInstruction(const MCInst &Inst) = 0;
/// EmitRawText - If this file is backed by a assembly streamer, this dumps
/// the specified string in the output .s file. This capability is
/// indicated by the hasRawTextSupport() predicate. By default this aborts.
virtual void EmitRawText(StringRef String);
void EmitRawText(const Twine &String);
/// ARM-related methods.
/// FIXME: Eventually we should have some "target MC streamer" and move
/// these methods there.
virtual void EmitFnStart();
virtual void EmitFnEnd();
virtual void EmitCantUnwind();
virtual void EmitPersonality(const MCSymbol *Personality);
virtual void EmitHandlerData();
virtual void EmitSetFP(unsigned FpReg, unsigned SpReg, int64_t Offset = 0);
virtual void EmitPad(int64_t Offset);
virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
bool isVector);
/// Finish - Finish emission of machine code.
virtual void Finish() = 0;
};
/// createNullStreamer - Create a dummy machine code streamer, which does
/// nothing. This is useful for timing the assembler front end.
MCStreamer *createNullStreamer(MCContext &Ctx);
/// createAsmStreamer - Create a machine code streamer which will print out
/// assembly for the native target, suitable for compiling with a native
/// assembler.
///
/// \param InstPrint - If given, the instruction printer to use. If not given
/// the MCInst representation will be printed. This method takes ownership of
/// InstPrint.
///
/// \param CE - If given, a code emitter to use to show the instruction
/// encoding inline with the assembly. This method takes ownership of \arg CE.
///
/// \param TAB - If given, a target asm backend to use to show the fixup
/// information in conjunction with encoding information. This method takes
/// ownership of \arg TAB.
///
/// \param ShowInst - Whether to show the MCInst representation inline with
/// the assembly.
///
/// \param DecodeLSDA - If true, emit comments that translates the LSDA into a
/// human readable format. Only usable with CFI.
MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
bool isVerboseAsm,
bool useLoc,
bool useCFI,
MCInstPrinter *InstPrint = 0,
MCCodeEmitter *CE = 0,
MCAsmBackend *TAB = 0,
bool ShowInst = false);
/// createMachOStreamer - Create a machine code streamer which will generate
/// Mach-O format object files.
///
/// Takes ownership of \arg TAB and \arg CE.
MCStreamer *createMachOStreamer(MCContext &Ctx, MCAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *CE,
bool RelaxAll = false);
/// createWinCOFFStreamer - Create a machine code streamer which will
/// generate Microsoft COFF format object files.
///
/// Takes ownership of \arg TAB and \arg CE.
MCStreamer *createWinCOFFStreamer(MCContext &Ctx,
MCAsmBackend &TAB,
MCCodeEmitter &CE, raw_ostream &OS,
bool RelaxAll = false);
/// createELFStreamer - Create a machine code streamer which will generate
/// ELF format object files.
MCStreamer *createELFStreamer(MCContext &Ctx, MCAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *CE,
bool RelaxAll, bool NoExecStack);
/// createLoggingStreamer - Create a machine code streamer which just logs the
/// API calls and then dispatches to another streamer.
///
/// The new streamer takes ownership of the \arg Child.
MCStreamer *createLoggingStreamer(MCStreamer *Child, raw_ostream &OS);
/// createPureStreamer - Create a machine code streamer which will generate
/// "pure" MC object files, for use with MC-JIT and testing tools.
///
/// Takes ownership of \arg TAB and \arg CE.
MCStreamer *createPureStreamer(MCContext &Ctx, MCAsmBackend &TAB,
raw_ostream &OS, MCCodeEmitter *CE);
} // end namespace llvm
#endif