//===- 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/System/DataTypes.h" #include "llvm/MC/MCDirectives.h" namespace llvm { class MCAsmInfo; class MCCodeEmitter; class MCContext; class MCExpr; class MCInst; class MCInstPrinter; class MCSection; class MCSymbol; class StringRef; class TargetAsmBackend; 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 protected: MCStreamer(MCContext &Ctx); /// CurSection - This is the current section code is being emitted to, it is /// kept up to date by SwitchSection. const MCSection *CurSection; public: virtual ~MCStreamer(); MCContext &getContext() const { return Context; } /// @name Assembly File Formatting. /// @{ /// isVerboseAsm - Return true if this streamer supports verbose assembly at /// all. 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 seciton that the streamer is /// emitting code to. const MCSection *getCurrentSection() const { return CurSection; } /// 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. virtual void SwitchSection(const MCSection *Section) = 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) = 0; /// EmitAssemblerFlag - Note in the output the specified @p Flag virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) = 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; /// 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; /// 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. virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) = 0; /// EmitZerofill - Emit a the zerofill section and an option 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 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(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 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); /// EmitSymbolValue - Special case of EmitValue that avoids the client /// having to pass in a MCExpr for MCSymbols. virtual void EmitSymbolValue(const MCSymbol *Sym, unsigned Size, unsigned AddrSpace); /// 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) = 0; /// 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 void EmitDwarfFileDirective(unsigned FileNo,StringRef Filename) = 0; /// 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); /// Finish - Finish emission of machine code and flush any output. 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. /// /// \param CE - If given, a code emitter to use to show the instruction /// encoding inline with the assembly. /// /// \param ShowInst - Whether to show the MCInst representation inline with /// the assembly. MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS, bool isLittleEndian, bool isVerboseAsm, MCInstPrinter *InstPrint = 0, MCCodeEmitter *CE = 0, bool ShowInst = false); /// createMachOStream - Create a machine code streamer which will generative /// Mach-O format object files. MCStreamer *createMachOStreamer(MCContext &Ctx, TargetAsmBackend &TAB, raw_ostream &OS, MCCodeEmitter *CE); } // end namespace llvm #endif