1 //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains a class to be used as the base class for target specific 11 // asm writers. This class primarily handles common functionality used by 12 // all asm writers. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_CODEGEN_ASMPRINTER_H 17 #define LLVM_CODEGEN_ASMPRINTER_H 18 19 #include "llvm/CodeGen/MachineFunctionPass.h" 20 #include "llvm/Support/DataTypes.h" 21 22 namespace llvm { 23 class BlockAddress; 24 class GCStrategy; 25 class Constant; 26 class ConstantArray; 27 class ConstantFP; 28 class ConstantInt; 29 class ConstantStruct; 30 class ConstantVector; 31 class GCMetadataPrinter; 32 class GlobalValue; 33 class GlobalVariable; 34 class MachineBasicBlock; 35 class MachineFunction; 36 class MachineInstr; 37 class MachineLocation; 38 class MachineLoopInfo; 39 class MachineLoop; 40 class MachineConstantPool; 41 class MachineConstantPoolEntry; 42 class MachineConstantPoolValue; 43 class MachineJumpTableInfo; 44 class MachineModuleInfo; 45 class MachineMove; 46 class MCAsmInfo; 47 class MCInst; 48 class MCContext; 49 class MCSection; 50 class MCStreamer; 51 class MCSymbol; 52 class MDNode; 53 class DwarfDebug; 54 class DwarfException; 55 class Mangler; 56 class TargetLoweringObjectFile; 57 class TargetData; 58 class TargetMachine; 59 class Twine; 60 class Type; 61 62 /// AsmPrinter - This class is intended to be used as a driving class for all 63 /// asm writers. 64 class AsmPrinter : public MachineFunctionPass { 65 public: 66 /// Target machine description. 67 /// 68 TargetMachine &TM; 69 70 /// Target Asm Printer information. 71 /// 72 const MCAsmInfo *MAI; 73 74 /// OutContext - This is the context for the output file that we are 75 /// streaming. This owns all of the global MC-related objects for the 76 /// generated translation unit. 77 MCContext &OutContext; 78 79 /// OutStreamer - This is the MCStreamer object for the file we are 80 /// generating. This contains the transient state for the current 81 /// translation unit that we are generating (such as the current section 82 /// etc). 83 MCStreamer &OutStreamer; 84 85 /// The current machine function. 86 const MachineFunction *MF; 87 88 /// MMI - This is a pointer to the current MachineModuleInfo. 89 MachineModuleInfo *MMI; 90 91 /// Name-mangler for global names. 92 /// 93 Mangler *Mang; 94 95 /// The symbol for the current function. This is recalculated at the 96 /// beginning of each call to runOnMachineFunction(). 97 /// 98 MCSymbol *CurrentFnSym; 99 100 private: 101 // GCMetadataPrinters - The garbage collection metadata printer table. 102 void *GCMetadataPrinters; // Really a DenseMap. 103 104 /// VerboseAsm - Emit comments in assembly output if this is true. 105 /// 106 bool VerboseAsm; 107 static char ID; 108 109 /// If VerboseAsm is set, a pointer to the loop info for this 110 /// function. 111 MachineLoopInfo *LI; 112 113 /// DD - If the target supports dwarf debug info, this pointer is non-null. 114 DwarfDebug *DD; 115 116 /// DE - If the target supports dwarf exception info, this pointer is 117 /// non-null. 118 DwarfException *DE; 119 120 protected: 121 explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer); 122 123 public: 124 virtual ~AsmPrinter(); 125 126 /// isVerbose - Return true if assembly output should contain comments. 127 /// 128 bool isVerbose() const { return VerboseAsm; } 129 130 /// getFunctionNumber - Return a unique ID for the current function. 131 /// 132 unsigned getFunctionNumber() const; 133 134 /// getObjFileLowering - Return information about object file lowering. 135 const TargetLoweringObjectFile &getObjFileLowering() const; 136 137 /// getTargetData - Return information about data layout. 138 const TargetData &getTargetData() const; 139 140 /// getCurrentSection() - Return the current section we are emitting to. 141 const MCSection *getCurrentSection() const; 142 143 144 //===------------------------------------------------------------------===// 145 // MachineFunctionPass Implementation. 146 //===------------------------------------------------------------------===// 147 148 /// getAnalysisUsage - Record analysis usage. 149 /// 150 void getAnalysisUsage(AnalysisUsage &AU) const; 151 152 /// doInitialization - Set up the AsmPrinter when we are working on a new 153 /// module. If your pass overrides this, it must make sure to explicitly 154 /// call this implementation. 155 bool doInitialization(Module &M); 156 157 /// doFinalization - Shut down the asmprinter. If you override this in your 158 /// pass, you must make sure to call it explicitly. 159 bool doFinalization(Module &M); 160 161 /// runOnMachineFunction - Emit the specified function out to the 162 /// OutStreamer. 163 virtual bool runOnMachineFunction(MachineFunction &MF) { 164 SetupMachineFunction(MF); 165 EmitFunctionHeader(); 166 EmitFunctionBody(); 167 return false; 168 } 169 170 //===------------------------------------------------------------------===// 171 // Coarse grained IR lowering routines. 172 //===------------------------------------------------------------------===// 173 174 /// SetupMachineFunction - This should be called when a new MachineFunction 175 /// is being processed from runOnMachineFunction. 176 void SetupMachineFunction(MachineFunction &MF); 177 178 /// EmitFunctionHeader - This method emits the header for the current 179 /// function. 180 void EmitFunctionHeader(); 181 182 /// EmitFunctionBody - This method emits the body and trailer for a 183 /// function. 184 void EmitFunctionBody(); 185 186 void emitPrologLabel(const MachineInstr &MI); 187 188 enum CFIMoveType { 189 CFI_M_None, 190 CFI_M_EH, 191 CFI_M_Debug 192 }; 193 CFIMoveType needsCFIMoves(); 194 195 bool needsSEHMoves(); 196 197 /// EmitConstantPool - Print to the current output stream assembly 198 /// representations of the constants in the constant pool MCP. This is 199 /// used to print out constants which have been "spilled to memory" by 200 /// the code generator. 201 /// 202 virtual void EmitConstantPool(); 203 204 /// EmitJumpTableInfo - Print assembly representations of the jump tables 205 /// used by the current function to the current output stream. 206 /// 207 void EmitJumpTableInfo(); 208 209 /// EmitGlobalVariable - Emit the specified global variable to the .s file. 210 virtual void EmitGlobalVariable(const GlobalVariable *GV); 211 212 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a 213 /// special global used by LLVM. If so, emit it and return true, otherwise 214 /// do nothing and return false. 215 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV); 216 217 /// EmitAlignment - Emit an alignment directive to the specified power of 218 /// two boundary. For example, if you pass in 3 here, you will get an 8 219 /// byte alignment. If a global value is specified, and if that global has 220 /// an explicit alignment requested, it will override the alignment request 221 /// if required for correctness. 222 /// 223 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const; 224 225 /// EmitBasicBlockStart - This method prints the label for the specified 226 /// MachineBasicBlock, an alignment (if present) and a comment describing 227 /// it if appropriate. 228 void EmitBasicBlockStart(const MachineBasicBlock *MBB) const; 229 230 /// EmitGlobalConstant - Print a general LLVM constant to the .s file. 231 void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0); 232 233 234 //===------------------------------------------------------------------===// 235 // Overridable Hooks 236 //===------------------------------------------------------------------===// 237 238 // Targets can, or in the case of EmitInstruction, must implement these to 239 // customize output. 240 241 /// EmitStartOfAsmFile - This virtual method can be overridden by targets 242 /// that want to emit something at the start of their file. 243 virtual void EmitStartOfAsmFile(Module &) {} 244 245 /// EmitEndOfAsmFile - This virtual method can be overridden by targets that 246 /// want to emit something at the end of their file. 247 virtual void EmitEndOfAsmFile(Module &) {} 248 249 /// EmitFunctionBodyStart - Targets can override this to emit stuff before 250 /// the first basic block in the function. 251 virtual void EmitFunctionBodyStart() {} 252 253 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after 254 /// the last basic block in the function. 255 virtual void EmitFunctionBodyEnd() {} 256 257 /// EmitInstruction - Targets should implement this to emit instructions. 258 virtual void EmitInstruction(const MachineInstr *) { 259 assert(0 && "EmitInstruction not implemented"); 260 } 261 262 virtual void EmitFunctionEntryLabel(); 263 264 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV); 265 266 /// isBlockOnlyReachableByFallthough - Return true if the basic block has 267 /// exactly one predecessor and the control transfer mechanism between 268 /// the predecessor and this block is a fall-through. 269 virtual bool 270 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const; 271 272 //===------------------------------------------------------------------===// 273 // Symbol Lowering Routines. 274 //===------------------------------------------------------------------===// 275 public: 276 277 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler 278 /// temporary label with the specified stem and unique ID. 279 MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const; 280 281 /// GetTempSymbol - Return an assembler temporary label with the specified 282 /// stem. 283 MCSymbol *GetTempSymbol(StringRef Name) const; 284 285 286 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 287 /// global value name as its base, with the specified suffix, and where the 288 /// symbol is forced to have private linkage if ForcePrivate is true. 289 MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV, 290 StringRef Suffix, 291 bool ForcePrivate = true) const; 292 293 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified 294 /// ExternalSymbol. 295 MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const; 296 297 /// GetCPISymbol - Return the symbol for the specified constant pool entry. 298 MCSymbol *GetCPISymbol(unsigned CPID) const; 299 300 /// GetJTISymbol - Return the symbol for the specified jump table entry. 301 MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const; 302 303 /// GetJTSetSymbol - Return the symbol for the specified jump table .set 304 /// FIXME: privatize to AsmPrinter. 305 MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const; 306 307 /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress 308 /// uses of the specified basic block. 309 MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const; 310 MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const; 311 312 //===------------------------------------------------------------------===// 313 // Emission Helper Routines. 314 //===------------------------------------------------------------------===// 315 public: 316 /// printOffset - This is just convenient handler for printing offsets. 317 void printOffset(int64_t Offset, raw_ostream &OS) const; 318 319 /// EmitInt8 - Emit a byte directive and value. 320 /// 321 void EmitInt8(int Value) const; 322 323 /// EmitInt16 - Emit a short directive and value. 324 /// 325 void EmitInt16(int Value) const; 326 327 /// EmitInt32 - Emit a long directive and value. 328 /// 329 void EmitInt32(int Value) const; 330 331 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 332 /// in bytes of the directive is specified by Size and Hi/Lo specify the 333 /// labels. This implicitly uses .set if it is available. 334 void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 335 unsigned Size) const; 336 337 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 338 /// where the size in bytes of the directive is specified by Size and Hi/Lo 339 /// specify the labels. This implicitly uses .set if it is available. 340 void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 341 const MCSymbol *Lo, unsigned Size) const; 342 343 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 344 /// where the size in bytes of the directive is specified by Size and Label 345 /// specifies the label. This implicitly uses .set if it is available. 346 void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 347 unsigned Size) const; 348 349 //===------------------------------------------------------------------===// 350 // Dwarf Emission Helper Routines 351 //===------------------------------------------------------------------===// 352 353 /// EmitSLEB128 - emit the specified signed leb128 value. 354 void EmitSLEB128(int Value, const char *Desc = 0) const; 355 356 /// EmitULEB128 - emit the specified unsigned leb128 value. 357 void EmitULEB128(unsigned Value, const char *Desc = 0, 358 unsigned PadTo = 0) const; 359 360 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value. 361 void EmitCFAByte(unsigned Val) const; 362 363 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an 364 /// encoding. If verbose assembly output is enabled, we output comments 365 /// describing the encoding. Desc is a string saying what the encoding is 366 /// specifying (e.g. "LSDA"). 367 void EmitEncodingByte(unsigned Val, const char *Desc = 0) const; 368 369 /// GetSizeOfEncodedValue - Return the size of the encoding in bytes. 370 unsigned GetSizeOfEncodedValue(unsigned Encoding) const; 371 372 /// EmitReference - Emit a reference to a label with a specified encoding. 373 /// 374 void EmitReference(const MCSymbol *Sym, unsigned Encoding) const; 375 void EmitReference(const GlobalValue *GV, unsigned Encoding) const; 376 377 /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of 378 /// its section. This can be done with a special directive if the target 379 /// supports it (e.g. cygwin) or by emitting it as an offset from a label at 380 /// the start of the section. 381 /// 382 /// SectionLabel is a temporary label emitted at the start of the section 383 /// that Label lives in. 384 void EmitSectionOffset(const MCSymbol *Label, 385 const MCSymbol *SectionLabel) const; 386 387 /// getDebugValueLocation - Get location information encoded by DBG_VALUE 388 /// operands. 389 virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const; 390 391 /// getISAEncoding - Get the value for DW_AT_APPLE_isa. Zero if no isa 392 /// encoding specified. 393 virtual unsigned getISAEncoding() { return 0; } 394 395 /// EmitDwarfRegOp - Emit dwarf register operation. 396 virtual void EmitDwarfRegOp(const MachineLocation &MLoc) const; 397 398 //===------------------------------------------------------------------===// 399 // Dwarf Lowering Routines 400 //===------------------------------------------------------------------===// 401 402 /// EmitCFIFrameMove - Emit frame instruction to describe the layout of the 403 /// frame. 404 void EmitCFIFrameMove(const MachineMove &Move) const; 405 406 //===------------------------------------------------------------------===// 407 // Inline Asm Support 408 //===------------------------------------------------------------------===// 409 public: 410 // These are hooks that targets can override to implement inline asm 411 // support. These should probably be moved out of AsmPrinter someday. 412 413 /// PrintSpecial - Print information related to the specified machine instr 414 /// that is independent of the operand, and may be independent of the instr 415 /// itself. This can be useful for portably encoding the comment character 416 /// or other bits of target-specific knowledge into the asmstrings. The 417 /// syntax used is ${:comment}. Targets can override this to add support 418 /// for their own strange codes. 419 virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS, 420 const char *Code) const; 421 422 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM 423 /// instruction, using the specified assembler variant. Targets should 424 /// override this to format as appropriate. This method can return true if 425 /// the operand is erroneous. 426 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 427 unsigned AsmVariant, const char *ExtraCode, 428 raw_ostream &OS); 429 430 /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM 431 /// instruction, using the specified assembler variant as an address. 432 /// Targets should override this to format as appropriate. This method can 433 /// return true if the operand is erroneous. 434 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, 435 unsigned AsmVariant, 436 const char *ExtraCode, 437 raw_ostream &OS); 438 439 private: 440 /// Private state for PrintSpecial() 441 // Assign a unique ID to this machine instruction. 442 mutable const MachineInstr *LastMI; 443 mutable unsigned LastFn; 444 mutable unsigned Counter; 445 mutable unsigned SetCounter; 446 447 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer. 448 void EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = 0) const; 449 450 /// EmitInlineAsm - This method formats and emits the specified machine 451 /// instruction that is an inline asm. 452 void EmitInlineAsm(const MachineInstr *MI) const; 453 454 //===------------------------------------------------------------------===// 455 // Internal Implementation Details 456 //===------------------------------------------------------------------===// 457 458 /// EmitVisibility - This emits visibility information about symbol, if 459 /// this is suported by the target. 460 void EmitVisibility(MCSymbol *Sym, unsigned Visibility, 461 bool IsDefinition = true) const; 462 463 void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const; 464 465 void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 466 const MachineBasicBlock *MBB, 467 unsigned uid) const; 468 void EmitLLVMUsedList(const Constant *List); 469 void EmitXXStructorList(const Constant *List); 470 GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C); 471 }; 472 } 473 474 #endif 475
