| //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file contains a class to be used as the base class for target specific |
| // asm writers. This class primarily handles common functionality used by |
| // all asm writers. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CODEGEN_ASMPRINTER_H |
| #define LLVM_CODEGEN_ASMPRINTER_H |
| |
| #include "llvm/ADT/Twine.h" |
| #include "llvm/CodeGen/MachineFunctionPass.h" |
| #include "llvm/IR/InlineAsm.h" |
| #include "llvm/Support/DataTypes.h" |
| #include "llvm/Support/ErrorHandling.h" |
| |
| namespace llvm { |
| class AsmPrinterHandler; |
| class BlockAddress; |
| class ByteStreamer; |
| class GCStrategy; |
| class Constant; |
| class ConstantArray; |
| class GCMetadataPrinter; |
| class GlobalValue; |
| class GlobalVariable; |
| class MachineBasicBlock; |
| class MachineFunction; |
| class MachineInstr; |
| class MachineLocation; |
| class MachineLoopInfo; |
| class MachineLoop; |
| class MachineConstantPoolValue; |
| class MachineJumpTableInfo; |
| class MachineModuleInfo; |
| class MCAsmInfo; |
| class MCCFIInstruction; |
| class MCContext; |
| class MCInst; |
| class MCInstrInfo; |
| class MCSection; |
| class MCStreamer; |
| class MCSubtargetInfo; |
| class MCSymbol; |
| class MDNode; |
| class DwarfDebug; |
| class Mangler; |
| class TargetLoweringObjectFile; |
| class DataLayout; |
| class TargetMachine; |
| |
| /// This class is intended to be used as a driving class for all asm writers. |
| class AsmPrinter : public MachineFunctionPass { |
| public: |
| /// Target machine description. |
| /// |
| TargetMachine &TM; |
| |
| /// Target Asm Printer information. |
| /// |
| const MCAsmInfo *MAI; |
| |
| const MCInstrInfo *MII; |
| /// This is the context for the output file that we are streaming. This owns |
| /// all of the global MC-related objects for the generated translation unit. |
| MCContext &OutContext; |
| |
| /// This is the MCStreamer object for the file we are generating. This |
| /// contains the transient state for the current translation unit that we are |
| /// generating (such as the current section etc). |
| MCStreamer &OutStreamer; |
| |
| /// The current machine function. |
| const MachineFunction *MF; |
| |
| /// This is a pointer to the current MachineModuleInfo. |
| MachineModuleInfo *MMI; |
| |
| /// Name-mangler for global names. |
| /// |
| Mangler *Mang; |
| |
| /// The symbol for the current function. This is recalculated at the beginning |
| /// of each call to runOnMachineFunction(). |
| /// |
| MCSymbol *CurrentFnSym; |
| |
| /// The symbol used to represent the start of the current function for the |
| /// purpose of calculating its size (e.g. using the .size directive). By |
| /// default, this is equal to CurrentFnSym. |
| MCSymbol *CurrentFnSymForSize; |
| |
| private: |
| // The garbage collection metadata printer table. |
| void *GCMetadataPrinters; // Really a DenseMap. |
| |
| /// Emit comments in assembly output if this is true. |
| /// |
| bool VerboseAsm; |
| static char ID; |
| |
| /// If VerboseAsm is set, a pointer to the loop info for this function. |
| MachineLoopInfo *LI; |
| |
| struct HandlerInfo { |
| AsmPrinterHandler *Handler; |
| const char *TimerName, *TimerGroupName; |
| HandlerInfo(AsmPrinterHandler *Handler, const char *TimerName, |
| const char *TimerGroupName) |
| : Handler(Handler), TimerName(TimerName), |
| TimerGroupName(TimerGroupName) {} |
| }; |
| /// A vector of all debug/EH info emitters we should use. This vector |
| /// maintains ownership of the emitters. |
| SmallVector<HandlerInfo, 1> Handlers; |
| |
| /// If the target supports dwarf debug info, this pointer is non-null. |
| DwarfDebug *DD; |
| |
| protected: |
| explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer); |
| |
| public: |
| virtual ~AsmPrinter(); |
| |
| DwarfDebug *getDwarfDebug() { return DD; } |
| |
| /// Return true if assembly output should contain comments. |
| /// |
| bool isVerbose() const { return VerboseAsm; } |
| |
| /// Return a unique ID for the current function. |
| /// |
| unsigned getFunctionNumber() const; |
| |
| /// Return information about object file lowering. |
| const TargetLoweringObjectFile &getObjFileLowering() const; |
| |
| /// Return information about data layout. |
| const DataLayout &getDataLayout() const; |
| |
| /// Return information about subtarget. |
| const MCSubtargetInfo &getSubtargetInfo() const; |
| |
| void EmitToStreamer(MCStreamer &S, const MCInst &Inst); |
| |
| /// Return the target triple string. |
| StringRef getTargetTriple() const; |
| |
| /// Return the current section we are emitting to. |
| const MCSection *getCurrentSection() const; |
| |
| void getNameWithPrefix(SmallVectorImpl<char> &Name, |
| const GlobalValue *GV) const; |
| |
| MCSymbol *getSymbol(const GlobalValue *GV) const; |
| |
| //===------------------------------------------------------------------===// |
| // MachineFunctionPass Implementation. |
| //===------------------------------------------------------------------===// |
| |
| /// Record analysis usage. |
| /// |
| void getAnalysisUsage(AnalysisUsage &AU) const override; |
| |
| /// Set up the AsmPrinter when we are working on a new module. If your pass |
| /// overrides this, it must make sure to explicitly call this implementation. |
| bool doInitialization(Module &M) override; |
| |
| /// Shut down the asmprinter. If you override this in your pass, you must make |
| /// sure to call it explicitly. |
| bool doFinalization(Module &M) override; |
| |
| /// Emit the specified function out to the OutStreamer. |
| bool runOnMachineFunction(MachineFunction &MF) override { |
| SetupMachineFunction(MF); |
| EmitFunctionHeader(); |
| EmitFunctionBody(); |
| return false; |
| } |
| |
| //===------------------------------------------------------------------===// |
| // Coarse grained IR lowering routines. |
| //===------------------------------------------------------------------===// |
| |
| /// This should be called when a new MachineFunction is being processed from |
| /// runOnMachineFunction. |
| void SetupMachineFunction(MachineFunction &MF); |
| |
| /// This method emits the header for the current function. |
| void EmitFunctionHeader(); |
| |
| /// This method emits the body and trailer for a function. |
| void EmitFunctionBody(); |
| |
| void emitCFIInstruction(const MachineInstr &MI); |
| |
| enum CFIMoveType { CFI_M_None, CFI_M_EH, CFI_M_Debug }; |
| CFIMoveType needsCFIMoves(); |
| |
| bool needsSEHMoves(); |
| |
| /// Print to the current output stream assembly representations of the |
| /// constants in the constant pool MCP. This is used to print out constants |
| /// which have been "spilled to memory" by the code generator. |
| /// |
| virtual void EmitConstantPool(); |
| |
| /// Print assembly representations of the jump tables used by the current |
| /// function to the current output stream. |
| /// |
| void EmitJumpTableInfo(); |
| |
| /// Emit the specified global variable to the .s file. |
| virtual void EmitGlobalVariable(const GlobalVariable *GV); |
| |
| /// Check to see if the specified global is a special global used by LLVM. If |
| /// so, emit it and return true, otherwise do nothing and return false. |
| bool EmitSpecialLLVMGlobal(const GlobalVariable *GV); |
| |
| /// Emit an alignment directive to the specified power of two boundary. For |
| /// example, if you pass in 3 here, you will get an 8 byte alignment. If a |
| /// global value is specified, and if that global has an explicit alignment |
| /// requested, it will override the alignment request if required for |
| /// correctness. |
| /// |
| void EmitAlignment(unsigned NumBits, const GlobalObject *GO = nullptr) const; |
| |
| /// This method prints the label for the specified MachineBasicBlock, an |
| /// alignment (if present) and a comment describing it if appropriate. |
| void EmitBasicBlockStart(const MachineBasicBlock &MBB) const; |
| |
| /// \brief Print a general LLVM constant to the .s file. |
| void EmitGlobalConstant(const Constant *CV); |
| |
| //===------------------------------------------------------------------===// |
| // Overridable Hooks |
| //===------------------------------------------------------------------===// |
| |
| // Targets can, or in the case of EmitInstruction, must implement these to |
| // customize output. |
| |
| /// This virtual method can be overridden by targets that want to emit |
| /// something at the start of their file. |
| virtual void EmitStartOfAsmFile(Module &) {} |
| |
| /// This virtual method can be overridden by targets that want to emit |
| /// something at the end of their file. |
| virtual void EmitEndOfAsmFile(Module &) {} |
| |
| /// Targets can override this to emit stuff before the first basic block in |
| /// the function. |
| virtual void EmitFunctionBodyStart() {} |
| |
| /// Targets can override this to emit stuff after the last basic block in the |
| /// function. |
| virtual void EmitFunctionBodyEnd() {} |
| |
| /// Targets should implement this to emit instructions. |
| virtual void EmitInstruction(const MachineInstr *) { |
| llvm_unreachable("EmitInstruction not implemented"); |
| } |
| |
| /// Return the symbol for the specified constant pool entry. |
| virtual MCSymbol *GetCPISymbol(unsigned CPID) const; |
| |
| virtual void EmitFunctionEntryLabel(); |
| |
| virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV); |
| |
| /// Targets can override this to change how global constants that are part of |
| /// a C++ static/global constructor list are emitted. |
| virtual void EmitXXStructor(const Constant *CV) { EmitGlobalConstant(CV); } |
| |
| /// Return true if the basic block has exactly one predecessor and the control |
| /// transfer mechanism between the predecessor and this block is a |
| /// fall-through. |
| virtual bool |
| isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const; |
| |
| /// Targets can override this to customize the output of IMPLICIT_DEF |
| /// instructions in verbose mode. |
| virtual void emitImplicitDef(const MachineInstr *MI) const; |
| |
| //===------------------------------------------------------------------===// |
| // Symbol Lowering Routines. |
| //===------------------------------------------------------------------===// |
| public: |
| /// Return the MCSymbol corresponding to the assembler temporary label with |
| /// the specified stem and unique ID. |
| MCSymbol *GetTempSymbol(Twine Name, unsigned ID) const; |
| |
| /// Return an assembler temporary label with the specified stem. |
| MCSymbol *GetTempSymbol(Twine Name) const; |
| |
| /// Return the MCSymbol for a private symbol with global value name as its |
| /// base, with the specified suffix. |
| MCSymbol *getSymbolWithGlobalValueBase(const GlobalValue *GV, |
| StringRef Suffix) const; |
| |
| /// Return the MCSymbol for the specified ExternalSymbol. |
| MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const; |
| |
| /// Return the symbol for the specified jump table entry. |
| MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const; |
| |
| /// Return the symbol for the specified jump table .set |
| /// FIXME: privatize to AsmPrinter. |
| MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const; |
| |
| /// Return the MCSymbol used to satisfy BlockAddress uses of the specified |
| /// basic block. |
| MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const; |
| MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const; |
| |
| //===------------------------------------------------------------------===// |
| // Emission Helper Routines. |
| //===------------------------------------------------------------------===// |
| public: |
| /// This is just convenient handler for printing offsets. |
| void printOffset(int64_t Offset, raw_ostream &OS) const; |
| |
| /// Emit a byte directive and value. |
| /// |
| void EmitInt8(int Value) const; |
| |
| /// Emit a short directive and value. |
| /// |
| void EmitInt16(int Value) const; |
| |
| /// Emit a long directive and value. |
| /// |
| void EmitInt32(int Value) const; |
| |
| /// Emit something like ".long Hi-Lo" where the size in bytes of the directive |
| /// is specified by Size and Hi/Lo specify the labels. This implicitly uses |
| /// .set if it is available. |
| void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, |
| unsigned Size) const; |
| |
| /// Emit something like ".long Hi+Offset-Lo" where the size in bytes of the |
| /// directive is specified by Size and Hi/Lo specify the labels. This |
| /// implicitly uses .set if it is available. |
| void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, |
| const MCSymbol *Lo, unsigned Size) const; |
| |
| /// Emit something like ".long Label+Offset" where the size in bytes of the |
| /// directive is specified by Size and Label specifies the label. This |
| /// implicitly uses .set if it is available. |
| void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, |
| unsigned Size, bool IsSectionRelative = false) const; |
| |
| /// Emit something like ".long Label" where the size in bytes of the directive |
| /// is specified by Size and Label specifies the label. |
| void EmitLabelReference(const MCSymbol *Label, unsigned Size, |
| bool IsSectionRelative = false) const { |
| EmitLabelPlusOffset(Label, 0, Size, IsSectionRelative); |
| } |
| |
| //===------------------------------------------------------------------===// |
| // Dwarf Emission Helper Routines |
| //===------------------------------------------------------------------===// |
| |
| /// Emit the specified signed leb128 value. |
| void EmitSLEB128(int64_t Value, const char *Desc = nullptr) const; |
| |
| /// Emit the specified unsigned leb128 value. |
| void EmitULEB128(uint64_t Value, const char *Desc = nullptr, |
| unsigned PadTo = 0) const; |
| |
| /// Emit a .byte 42 directive for a DW_CFA_xxx value. |
| void EmitCFAByte(unsigned Val) const; |
| |
| /// Emit a .byte 42 directive that corresponds to an encoding. If verbose |
| /// assembly output is enabled, we output comments describing the encoding. |
| /// Desc is a string saying what the encoding is specifying (e.g. "LSDA"). |
| void EmitEncodingByte(unsigned Val, const char *Desc = nullptr) const; |
| |
| /// Return the size of the encoding in bytes. |
| unsigned GetSizeOfEncodedValue(unsigned Encoding) const; |
| |
| /// Emit reference to a ttype global with a specified encoding. |
| void EmitTTypeReference(const GlobalValue *GV, unsigned Encoding) const; |
| |
| /// Emit the 4-byte offset of Label from the start of its section. This can |
| /// be done with a special directive if the target supports it (e.g. cygwin) |
| /// or by emitting it as an offset from a label at the start of the section. |
| /// |
| /// SectionLabel is a temporary label emitted at the start of the section |
| /// that Label lives in. |
| void EmitSectionOffset(const MCSymbol *Label, |
| const MCSymbol *SectionLabel) const; |
| |
| /// Get the value for DW_AT_APPLE_isa. Zero if no isa encoding specified. |
| virtual unsigned getISAEncoding() { return 0; } |
| |
| /// \brief Emit a partial DWARF register operation. |
| /// \param MLoc the register |
| /// \param PieceSize size and |
| /// \param PieceOffset offset of the piece in bits, if this is one |
| /// piece of an aggregate value. |
| /// |
| /// If size and offset is zero an operation for the entire |
| /// register is emitted: Some targets do not provide a DWARF |
| /// register number for every register. If this is the case, this |
| /// function will attempt to emit a DWARF register by emitting a |
| /// piece of a super-register or by piecing together multiple |
| /// subregisters that alias the register. |
| void EmitDwarfRegOpPiece(ByteStreamer &BS, const MachineLocation &MLoc, |
| unsigned PieceSize = 0, |
| unsigned PieceOffset = 0) const; |
| |
| /// Emit dwarf register operation. |
| /// \param Indirect whether this is a register-indirect address |
| virtual void EmitDwarfRegOp(ByteStreamer &BS, const MachineLocation &MLoc, |
| bool Indirect) const; |
| |
| //===------------------------------------------------------------------===// |
| // Dwarf Lowering Routines |
| //===------------------------------------------------------------------===// |
| |
| /// \brief Emit frame instruction to describe the layout of the frame. |
| void emitCFIInstruction(const MCCFIInstruction &Inst) const; |
| |
| //===------------------------------------------------------------------===// |
| // Inline Asm Support |
| //===------------------------------------------------------------------===// |
| public: |
| // These are hooks that targets can override to implement inline asm |
| // support. These should probably be moved out of AsmPrinter someday. |
| |
| /// Print information related to the specified machine instr that is |
| /// independent of the operand, and may be independent of the instr itself. |
| /// This can be useful for portably encoding the comment character or other |
| /// bits of target-specific knowledge into the asmstrings. The syntax used is |
| /// ${:comment}. Targets can override this to add support for their own |
| /// strange codes. |
| virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS, |
| const char *Code) const; |
| |
| /// Print the specified operand of MI, an INLINEASM instruction, using the |
| /// specified assembler variant. Targets should override this to format as |
| /// appropriate. This method can return true if the operand is erroneous. |
| virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, |
| unsigned AsmVariant, const char *ExtraCode, |
| raw_ostream &OS); |
| |
| /// Print the specified operand of MI, an INLINEASM instruction, using the |
| /// specified assembler variant as an address. Targets should override this to |
| /// format as appropriate. This method can return true if the operand is |
| /// erroneous. |
| virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, |
| unsigned AsmVariant, const char *ExtraCode, |
| raw_ostream &OS); |
| |
| /// Let the target do anything it needs to do after emitting inlineasm. |
| /// This callback can be used restore the original mode in case the |
| /// inlineasm contains directives to switch modes. |
| /// \p StartInfo - the original subtarget info before inline asm |
| /// \p EndInfo - the final subtarget info after parsing the inline asm, |
| /// or NULL if the value is unknown. |
| virtual void emitInlineAsmEnd(const MCSubtargetInfo &StartInfo, |
| const MCSubtargetInfo *EndInfo) const; |
| |
| private: |
| /// Private state for PrintSpecial() |
| // Assign a unique ID to this machine instruction. |
| mutable const MachineInstr *LastMI; |
| mutable unsigned LastFn; |
| mutable unsigned Counter; |
| mutable unsigned SetCounter; |
| |
| /// Emit a blob of inline asm to the output streamer. |
| void |
| EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = nullptr, |
| InlineAsm::AsmDialect AsmDialect = InlineAsm::AD_ATT) const; |
| |
| /// This method formats and emits the specified machine instruction that is an |
| /// inline asm. |
| void EmitInlineAsm(const MachineInstr *MI) const; |
| |
| //===------------------------------------------------------------------===// |
| // Internal Implementation Details |
| //===------------------------------------------------------------------===// |
| |
| /// This emits visibility information about symbol, if this is suported by the |
| /// target. |
| void EmitVisibility(MCSymbol *Sym, unsigned Visibility, |
| bool IsDefinition = true) const; |
| |
| void EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const; |
| |
| void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, |
| const MachineBasicBlock *MBB, unsigned uid) const; |
| void EmitLLVMUsedList(const ConstantArray *InitList); |
| /// Emit llvm.ident metadata in an '.ident' directive. |
| void EmitModuleIdents(Module &M); |
| void EmitXXStructorList(const Constant *List, bool isCtor); |
| GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy &C); |
| }; |
| } |
| |
| #endif |