llvm-6502/include/llvm/MC/MCStreamer.h
2010-03-11 01:34:27 +00:00

316 lines
13 KiB
C++

//===- 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; }
/// 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;
/// @}
/// @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;
/// 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,
const MCAsmInfo &MAI, 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