+ /// 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, std::unique_ptr<MCStreamer> Streamer);
+
+public:
+ ~AsmPrinter() override;
+
+ DwarfDebug *getDwarfDebug() { return DD; }
+ DwarfDebug *getDwarfDebug() const { 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;
+
+ MCSymbol *getFunctionBegin() const { return CurrentFnBegin; }
+ MCSymbol *getFunctionEnd() const { return CurrentFnEnd; }
+ MCSymbol *getCurExceptionSym();
+
+ /// Return information about object file lowering.
+ const TargetLoweringObjectFile &getObjFileLowering() const;
+
+ /// Return information about data layout.
+ const DataLayout &getDataLayout() const;
+
+ /// Return the pointer size from the TargetMachine
+ unsigned getPointerSize() 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);
+ 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 body and trailer for a function.
+ void EmitFunctionBody();
+
+ void emitCFIInstruction(const MachineInstr &MI);
+
+ void emitFrameAlloc(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.
+ ///
+ virtual void EmitJumpTableInfo();
+
+ /// Emit the control variable for an emulated TLS variable.
+ virtual void EmitEmulatedTLSControlVariable(const GlobalVariable *GV,
+ MCSymbol *EmittedSym,
+ bool AllZeroInitValue);
+
+ /// 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;
+
+ /// Lower the specified LLVM Constant to an MCExpr.
+ const MCExpr *lowerConstant(const Constant *CV);
+
+ /// \brief Print a general LLVM constant to the .s file.
+ void EmitGlobalConstant(const DataLayout &DL, const Constant *CV);
+
+ /// \brief Unnamed constant global variables solely contaning a pointer to
+ /// another globals variable act like a global variable "proxy", or GOT
+ /// equivalents, i.e., it's only used to hold the address of the latter. One
+ /// optimization is to replace accesses to these proxies by using the GOT
+ /// entry for the final global instead. Hence, we select GOT equivalent
+ /// candidates among all the module global variables, avoid emitting them
+ /// unnecessarily and finally replace references to them by pc relative
+ /// accesses to GOT entries.
+ void computeGlobalGOTEquivs(Module &M);
+
+ /// \brief Constant expressions using GOT equivalent globals may not be
+ /// eligible for PC relative GOT entry conversion, in such cases we need to
+ /// emit the proxies we previously omitted in EmitGlobalVariable.
+ void emitGlobalGOTEquivs();
+
+ //===------------------------------------------------------------------===//
+ // 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 can override this to emit stuff at the start of a basic block.
+ /// By default, this method prints the label for the specified
+ /// MachineBasicBlock, an alignment (if present) and a comment describing it
+ /// if appropriate.
+ virtual void EmitBasicBlockStart(const MachineBasicBlock &MBB) const;
+
+ /// Targets can override this to emit stuff at the end of a basic block.
+ virtual void EmitBasicBlockEnd(const MachineBasicBlock &MBB) {}
+
+ /// 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 DataLayout &DL, const Constant *CV) {
+ EmitGlobalConstant(DL, 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:
+ MCSymbol *createTempSymbol(const 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 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 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 a reference to a symbol for use in dwarf. Different object formats
+ /// represent this in different ways. Some use a relocation others encode
+ /// the label offset in its section.
+ void emitDwarfSymbolReference(const MCSymbol *Label,
+ bool ForceOffset = false) const;
+
+ /// Emit the 4-byte offset of a string from the start of its section.
+ ///
+ /// When possible, emit a DwarfStringPool section offset without any
+ /// relocations, and without using the symbol. Otherwise, defers to \a
+ /// emitDwarfSymbolReference().
+ void emitDwarfStringOffset(DwarfStringPoolEntryRef S) const;
+
+ /// Get the value for DW_AT_APPLE_isa. Zero if no isa encoding specified.
+ virtual unsigned getISAEncoding() { return 0; }
+
+ /// EmitDwarfRegOp - Emit a dwarf register operation.
+ virtual void EmitDwarfRegOp(ByteStreamer &BS,
+ const MachineLocation &MLoc) const;
+
+ //===------------------------------------------------------------------===//
+ // Dwarf Lowering Routines
+ //===------------------------------------------------------------------===//
+
+ /// \brief Emit frame instruction to describe the layout of the frame.
+ void emitCFIInstruction(const MCCFIInstruction &Inst) const;
+
+ /// \brief Emit Dwarf abbreviation table.
+ void emitDwarfAbbrevs(const std::vector<DIEAbbrev *>& Abbrevs) const;
+
+ /// \brief Recursively emit Dwarf DIE tree.
+ void emitDwarfDIE(const DIE &Die) 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 before emitting inlineasm.
+ /// \p StartInfo - the subtarget info before parsing inline asm
+ virtual void emitInlineAsmStart() const;
+
+ /// 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;
+
+ /// This method emits the header for the current function.
+ virtual void EmitFunctionHeader();
+
+ /// Emit a blob of inline asm to the output streamer.
+ void
+ EmitInlineAsm(StringRef Str, const MCSubtargetInfo &STI,
+ const MCTargetOptions &MCOptions,
+ 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 DataLayout &DL, const Constant *List,
+ bool isCtor);
+ GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy &C);
+};