AsmPrinter.h revision 0d805c33d134d88169e3dc4a3272cff9a5713ce7
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/DebugLoc.h" 21 22namespace 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 MachineLoopInfo; 38 class MachineLoop; 39 class MachineConstantPool; 40 class MachineConstantPoolEntry; 41 class MachineConstantPoolValue; 42 class MachineJumpTableInfo; 43 class MachineModuleInfo; 44 class MachineMove; 45 class MCAsmInfo; 46 class MCInst; 47 class MCContext; 48 class MCSection; 49 class MCStreamer; 50 class MCSymbol; 51 class DwarfDebug; 52 class DwarfException; 53 class Mangler; 54 class TargetLoweringObjectFile; 55 class TargetData; 56 class Twine; 57 class Type; 58 59 /// AsmPrinter - This class is intended to be used as a driving class for all 60 /// asm writers. 61 class AsmPrinter : public MachineFunctionPass { 62 public: 63 /// Target machine description. 64 /// 65 TargetMachine &TM; 66 67 /// Target Asm Printer information. 68 /// 69 const MCAsmInfo *MAI; 70 71 /// OutContext - This is the context for the output file that we are 72 /// streaming. This owns all of the global MC-related objects for the 73 /// generated translation unit. 74 MCContext &OutContext; 75 76 /// OutStreamer - This is the MCStreamer object for the file we are 77 /// generating. This contains the transient state for the current 78 /// translation unit that we are generating (such as the current section 79 /// etc). 80 MCStreamer &OutStreamer; 81 82 /// The current machine function. 83 const MachineFunction *MF; 84 85 /// MMI - This is a pointer to the current MachineModuleInfo. 86 MachineModuleInfo *MMI; 87 88 /// Name-mangler for global names. 89 /// 90 Mangler *Mang; 91 92 /// The symbol for the current function. This is recalculated at the 93 /// beginning of each call to runOnMachineFunction(). 94 /// 95 MCSymbol *CurrentFnSym; 96 97 private: 98 // GCMetadataPrinters - The garbage collection metadata printer table. 99 void *GCMetadataPrinters; // Really a DenseMap. 100 101 /// VerboseAsm - Emit comments in assembly output if this is true. 102 /// 103 bool VerboseAsm; 104 static char ID; 105 106 /// If VerboseAsm is set, a pointer to the loop info for this 107 /// function. 108 MachineLoopInfo *LI; 109 110 /// DD - If the target supports dwarf debug info, this pointer is non-null. 111 DwarfDebug *DD; 112 113 /// DE - If the target supports dwarf exception info, this pointer is 114 /// non-null. 115 DwarfException *DE; 116 117 protected: 118 explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer); 119 120 public: 121 virtual ~AsmPrinter(); 122 123 /// isVerbose - Return true if assembly output should contain comments. 124 /// 125 bool isVerbose() const { return VerboseAsm; } 126 127 /// getFunctionNumber - Return a unique ID for the current function. 128 /// 129 unsigned getFunctionNumber() const; 130 131 /// getObjFileLowering - Return information about object file lowering. 132 const TargetLoweringObjectFile &getObjFileLowering() const; 133 134 /// getTargetData - Return information about data layout. 135 const TargetData &getTargetData() const; 136 137 /// getCurrentSection() - Return the current section we are emitting to. 138 const MCSection *getCurrentSection() const; 139 140 141 //===------------------------------------------------------------------===// 142 // MachineFunctionPass Implementation. 143 //===------------------------------------------------------------------===// 144 145 /// getAnalysisUsage - Record analysis usage. 146 /// 147 void getAnalysisUsage(AnalysisUsage &AU) const; 148 149 /// doInitialization - Set up the AsmPrinter when we are working on a new 150 /// module. If your pass overrides this, it must make sure to explicitly 151 /// call this implementation. 152 bool doInitialization(Module &M); 153 154 /// doFinalization - Shut down the asmprinter. If you override this in your 155 /// pass, you must make sure to call it explicitly. 156 bool doFinalization(Module &M); 157 158 /// runOnMachineFunction - Emit the specified function out to the 159 /// OutStreamer. 160 virtual bool runOnMachineFunction(MachineFunction &MF) { 161 SetupMachineFunction(MF); 162 EmitFunctionHeader(); 163 EmitFunctionBody(); 164 return false; 165 } 166 167 //===------------------------------------------------------------------===// 168 // Coarse grained IR lowering routines. 169 //===------------------------------------------------------------------===// 170 171 /// SetupMachineFunction - This should be called when a new MachineFunction 172 /// is being processed from runOnMachineFunction. 173 void SetupMachineFunction(MachineFunction &MF); 174 175 /// EmitFunctionHeader - This method emits the header for the current 176 /// function. 177 void EmitFunctionHeader(); 178 179 /// EmitFunctionBody - This method emits the body and trailer for a 180 /// function. 181 void EmitFunctionBody(); 182 183 /// EmitConstantPool - Print to the current output stream assembly 184 /// representations of the constants in the constant pool MCP. This is 185 /// used to print out constants which have been "spilled to memory" by 186 /// the code generator. 187 /// 188 virtual void EmitConstantPool(); 189 190 /// EmitJumpTableInfo - Print assembly representations of the jump tables 191 /// used by the current function to the current output stream. 192 /// 193 void EmitJumpTableInfo(); 194 195 /// EmitGlobalVariable - Emit the specified global variable to the .s file. 196 virtual void EmitGlobalVariable(const GlobalVariable *GV); 197 198 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a 199 /// special global used by LLVM. If so, emit it and return true, otherwise 200 /// do nothing and return false. 201 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV); 202 203 /// EmitAlignment - Emit an alignment directive to the specified power of 204 /// two boundary. For example, if you pass in 3 here, you will get an 8 205 /// byte alignment. If a global value is specified, and if that global has 206 /// an explicit alignment requested, it will unconditionally override the 207 /// alignment request. However, if ForcedAlignBits is specified, this value 208 /// has final say: the ultimate alignment will be the max of ForcedAlignBits 209 /// and the alignment computed with NumBits and the global. If UseFillExpr 210 /// is true, it also emits an optional second value FillValue which the 211 /// assembler uses to fill gaps to match alignment for text sections if the 212 /// has specified a non-zero fill value. 213 /// 214 /// The algorithm is: 215 /// Align = NumBits; 216 /// if (GV && GV->hasalignment) Align = GV->getalignment(); 217 /// Align = std::max(Align, ForcedAlignBits); 218 /// 219 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0, 220 unsigned ForcedAlignBits = 0, 221 bool UseFillExpr = true) const; 222 223 /// EmitBasicBlockStart - This method prints the label for the specified 224 /// MachineBasicBlock, an alignment (if present) and a comment describing 225 /// it if appropriate. 226 void EmitBasicBlockStart(const MachineBasicBlock *MBB) const; 227 228 229 /// EmitGlobalConstant - Print a general LLVM constant to the .s file. 230 void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0); 231 232 233 //===------------------------------------------------------------------===// 234 // Overridable Hooks 235 //===------------------------------------------------------------------===// 236 237 // Targets can, or in the case of EmitInstruction, must implement these to 238 // customize output. 239 240 /// EmitStartOfAsmFile - This virtual method can be overridden by targets 241 /// that want to emit something at the start of their file. 242 virtual void EmitStartOfAsmFile(Module &) {} 243 244 /// EmitEndOfAsmFile - This virtual method can be overridden by targets that 245 /// want to emit something at the end of their file. 246 virtual void EmitEndOfAsmFile(Module &) {} 247 248 /// EmitFunctionBodyStart - Targets can override this to emit stuff before 249 /// the first basic block in the function. 250 virtual void EmitFunctionBodyStart() {} 251 252 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after 253 /// the last basic block in the function. 254 virtual void EmitFunctionBodyEnd() {} 255 256 /// EmitInstruction - Targets should implement this to emit instructions. 257 virtual void EmitInstruction(const MachineInstr *) { 258 assert(0 && "EmitInstruction not implemented"); 259 } 260 261 virtual void EmitFunctionEntryLabel(); 262 263 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV); 264 265 /// isBlockOnlyReachableByFallthough - Return true if the basic block has 266 /// exactly one predecessor and the control transfer mechanism between 267 /// the predecessor and this block is a fall-through. 268 virtual bool 269 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const; 270 271 //===------------------------------------------------------------------===// 272 // Symbol Lowering Routines. 273 //===------------------------------------------------------------------===// 274 public: 275 276 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler 277 /// temporary label with the specified stem and unique ID. 278 MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const; 279 280 /// GetTempSymbol - Return an assembler temporary label with the specified 281 /// stem. 282 MCSymbol *GetTempSymbol(StringRef Name) const; 283 284 285 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 286 /// global value name as its base, with the specified suffix, and where the 287 /// symbol is forced to have private linkage if ForcePrivate is true. 288 MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV, 289 StringRef Suffix, 290 bool ForcePrivate = true) const; 291 292 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified 293 /// ExternalSymbol. 294 MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const; 295 296 /// GetCPISymbol - Return the symbol for the specified constant pool entry. 297 MCSymbol *GetCPISymbol(unsigned CPID) const; 298 299 /// GetJTISymbol - Return the symbol for the specified jump table entry. 300 MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const; 301 302 /// GetJTSetSymbol - Return the symbol for the specified jump table .set 303 /// FIXME: privatize to AsmPrinter. 304 MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const; 305 306 /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress 307 /// uses of the specified basic block. 308 MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const; 309 MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const; 310 311 //===------------------------------------------------------------------===// 312 // Emission Helper Routines. 313 //===------------------------------------------------------------------===// 314 public: 315 /// printOffset - This is just convenient handler for printing offsets. 316 void printOffset(int64_t Offset, raw_ostream &OS) const; 317 318 /// EmitInt8 - Emit a byte directive and value. 319 /// 320 void EmitInt8(int Value) const; 321 322 /// EmitInt16 - Emit a short directive and value. 323 /// 324 void EmitInt16(int Value) const; 325 326 /// EmitInt32 - Emit a long directive and value. 327 /// 328 void EmitInt32(int Value) const; 329 330 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 331 /// in bytes of the directive is specified by Size and Hi/Lo specify the 332 /// labels. This implicitly uses .set if it is available. 333 void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 334 unsigned Size) const; 335 336 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 337 /// where the size in bytes of the directive is specified by Size and Hi/Lo 338 /// specify the labels. This implicitly uses .set if it is available. 339 void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 340 const MCSymbol *Lo, unsigned Size) const; 341 342 //===------------------------------------------------------------------===// 343 // Dwarf Emission Helper Routines 344 //===------------------------------------------------------------------===// 345 346 /// EmitSLEB128 - emit the specified signed leb128 value. 347 void EmitSLEB128(int Value, const char *Desc = 0) const; 348 349 /// EmitULEB128 - emit the specified unsigned leb128 value. 350 void EmitULEB128(unsigned Value, const char *Desc = 0, 351 unsigned PadTo = 0) const; 352 353 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value. 354 void EmitCFAByte(unsigned Val) const; 355 356 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an 357 /// encoding. If verbose assembly output is enabled, we output comments 358 /// describing the encoding. Desc is a string saying what the encoding is 359 /// specifying (e.g. "LSDA"). 360 void EmitEncodingByte(unsigned Val, const char *Desc = 0) const; 361 362 /// GetSizeOfEncodedValue - Return the size of the encoding in bytes. 363 unsigned GetSizeOfEncodedValue(unsigned Encoding) const; 364 365 /// EmitReference - Emit a reference to a label with a specified encoding. 366 /// 367 void EmitReference(const MCSymbol *Sym, unsigned Encoding) const; 368 void EmitReference(const GlobalValue *GV, unsigned Encoding) const; 369 370 /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of 371 /// its section. This can be done with a special directive if the target 372 /// supports it (e.g. cygwin) or by emitting it as an offset from a label at 373 /// the start of the section. 374 /// 375 /// SectionLabel is a temporary label emitted at the start of the section 376 /// that Label lives in. 377 void EmitSectionOffset(const MCSymbol *Label, 378 const MCSymbol *SectionLabel) const; 379 380 //===------------------------------------------------------------------===// 381 // Dwarf Lowering Routines 382 //===------------------------------------------------------------------===// 383 384 /// EmitFrameMoves - Emit frame instructions to describe the layout of the 385 /// frame. 386 void EmitFrameMoves(const std::vector<MachineMove> &Moves, 387 MCSymbol *BaseLabel, bool isEH) const; 388 389 390 //===------------------------------------------------------------------===// 391 // Inline Asm Support 392 //===------------------------------------------------------------------===// 393 public: 394 // These are hooks that targets can override to implement inline asm 395 // support. These should probably be moved out of AsmPrinter someday. 396 397 /// PrintSpecial - Print information related to the specified machine instr 398 /// that is independent of the operand, and may be independent of the instr 399 /// itself. This can be useful for portably encoding the comment character 400 /// or other bits of target-specific knowledge into the asmstrings. The 401 /// syntax used is ${:comment}. Targets can override this to add support 402 /// for their own strange codes. 403 virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS, 404 const char *Code) const; 405 406 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM 407 /// instruction, using the specified assembler variant. Targets should 408 /// override this to format as appropriate. This method can return true if 409 /// the operand is erroneous. 410 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, 411 unsigned AsmVariant, const char *ExtraCode, 412 raw_ostream &OS); 413 414 /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM 415 /// instruction, using the specified assembler variant as an address. 416 /// Targets should override this to format as appropriate. This method can 417 /// return true if the operand is erroneous. 418 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, 419 unsigned AsmVariant, 420 const char *ExtraCode, 421 raw_ostream &OS); 422 423 private: 424 /// Private state for PrintSpecial() 425 // Assign a unique ID to this machine instruction. 426 mutable const MachineInstr *LastMI; 427 mutable unsigned LastFn; 428 mutable unsigned Counter; 429 mutable unsigned SetCounter; 430 431 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer. 432 void EmitInlineAsm(StringRef Str, unsigned LocCookie) const; 433 434 /// EmitInlineAsm - This method formats and emits the specified machine 435 /// instruction that is an inline asm. 436 void EmitInlineAsm(const MachineInstr *MI) const; 437 438 //===------------------------------------------------------------------===// 439 // Internal Implementation Details 440 //===------------------------------------------------------------------===// 441 442 /// EmitVisibility - This emits visibility information about symbol, if 443 /// this is suported by the target. 444 void EmitVisibility(MCSymbol *Sym, unsigned Visibility) const; 445 446 void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const; 447 448 void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 449 const MachineBasicBlock *MBB, 450 unsigned uid) const; 451 void EmitLLVMUsedList(Constant *List); 452 void EmitXXStructorList(Constant *List); 453 GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C); 454 }; 455} 456 457#endif 458