1 //===-- llvm/CodeGen/AsmPrinter.h - AsmPrinter Framework --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_CODEGEN_ASMPRINTER_H
17 #define LLVM_CODEGEN_ASMPRINTER_H
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/IR/InlineAsm.h"
21 #include "llvm/Support/DataTypes.h"
22 #include "llvm/Support/ErrorHandling.h"
28 class GCMetadataPrinter;
31 class MachineBasicBlock;
32 class MachineFunction;
34 class MachineLocation;
35 class MachineLoopInfo;
37 class MachineConstantPoolValue;
38 class MachineJumpTableInfo;
39 class MachineModuleInfo;
50 class TargetLoweringObjectFile;
54 /// AsmPrinter - This class is intended to be used as a driving class for all
56 class AsmPrinter : public MachineFunctionPass {
58 /// Target machine description.
62 /// Target Asm Printer information.
66 /// OutContext - This is the context for the output file that we are
67 /// streaming. This owns all of the global MC-related objects for the
68 /// generated translation unit.
69 MCContext &OutContext;
71 /// OutStreamer - This is the MCStreamer object for the file we are
72 /// generating. This contains the transient state for the current
73 /// translation unit that we are generating (such as the current section
75 MCStreamer &OutStreamer;
77 /// The current machine function.
78 const MachineFunction *MF;
80 /// MMI - This is a pointer to the current MachineModuleInfo.
81 MachineModuleInfo *MMI;
83 /// Name-mangler for global names.
87 /// The symbol for the current function. This is recalculated at the
88 /// beginning of each call to runOnMachineFunction().
90 MCSymbol *CurrentFnSym;
92 /// The symbol used to represent the start of the current function for the
93 /// purpose of calculating its size (e.g. using the .size directive). By
94 /// default, this is equal to CurrentFnSym.
95 MCSymbol *CurrentFnSymForSize;
98 // GCMetadataPrinters - The garbage collection metadata printer table.
99 void *GCMetadataPrinters; // Really a DenseMap.
101 /// VerboseAsm - Emit comments in assembly output if this is true.
106 /// If VerboseAsm is set, a pointer to the loop info for this
110 /// DD - If the target supports dwarf debug info, this pointer is non-null.
113 /// DE - If the target supports dwarf exception info, this pointer is
118 explicit AsmPrinter(TargetMachine &TM, MCStreamer &Streamer);
121 virtual ~AsmPrinter();
123 /// isVerbose - Return true if assembly output should contain comments.
125 bool isVerbose() const { return VerboseAsm; }
127 /// getFunctionNumber - Return a unique ID for the current function.
129 unsigned getFunctionNumber() const;
131 /// getObjFileLowering - Return information about object file lowering.
132 const TargetLoweringObjectFile &getObjFileLowering() const;
134 /// getDataLayout - Return information about data layout.
135 const DataLayout &getDataLayout() const;
137 /// getCurrentSection() - Return the current section we are emitting to.
138 const MCSection *getCurrentSection() const;
141 //===------------------------------------------------------------------===//
142 // MachineFunctionPass Implementation.
143 //===------------------------------------------------------------------===//
145 /// getAnalysisUsage - Record analysis usage.
147 void getAnalysisUsage(AnalysisUsage &AU) const;
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);
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);
158 /// runOnMachineFunction - Emit the specified function out to the
160 virtual bool runOnMachineFunction(MachineFunction &MF) {
161 SetupMachineFunction(MF);
162 EmitFunctionHeader();
167 //===------------------------------------------------------------------===//
168 // Coarse grained IR lowering routines.
169 //===------------------------------------------------------------------===//
171 /// SetupMachineFunction - This should be called when a new MachineFunction
172 /// is being processed from runOnMachineFunction.
173 void SetupMachineFunction(MachineFunction &MF);
175 /// EmitFunctionHeader - This method emits the header for the current
177 void EmitFunctionHeader();
179 /// EmitFunctionBody - This method emits the body and trailer for a
181 void EmitFunctionBody();
183 void emitPrologLabel(const MachineInstr &MI);
190 CFIMoveType needsCFIMoves();
192 bool needsSEHMoves();
194 /// needsRelocationsForDwarfStringPool - Specifies whether the object format
195 /// expects to use relocations to refer to debug entries. Alternatively we
196 /// emit section offsets in bytes from the start of the string pool.
197 bool needsRelocationsForDwarfStringPool() const;
199 /// EmitConstantPool - Print to the current output stream assembly
200 /// representations of the constants in the constant pool MCP. This is
201 /// used to print out constants which have been "spilled to memory" by
202 /// the code generator.
204 virtual void EmitConstantPool();
206 /// EmitJumpTableInfo - Print assembly representations of the jump tables
207 /// used by the current function to the current output stream.
209 void EmitJumpTableInfo();
211 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
212 virtual void EmitGlobalVariable(const GlobalVariable *GV);
214 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
215 /// special global used by LLVM. If so, emit it and return true, otherwise
216 /// do nothing and return false.
217 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
219 /// EmitAlignment - Emit an alignment directive to the specified power of
220 /// two boundary. For example, if you pass in 3 here, you will get an 8
221 /// byte alignment. If a global value is specified, and if that global has
222 /// an explicit alignment requested, it will override the alignment request
223 /// if required for correctness.
225 void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0) const;
227 /// EmitBasicBlockStart - This method prints the label for the specified
228 /// MachineBasicBlock, an alignment (if present) and a comment describing
229 /// it if appropriate.
230 void EmitBasicBlockStart(const MachineBasicBlock *MBB) const;
232 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
233 void EmitGlobalConstant(const Constant *CV, unsigned AddrSpace = 0);
236 //===------------------------------------------------------------------===//
238 //===------------------------------------------------------------------===//
240 // Targets can, or in the case of EmitInstruction, must implement these to
243 /// EmitStartOfAsmFile - This virtual method can be overridden by targets
244 /// that want to emit something at the start of their file.
245 virtual void EmitStartOfAsmFile(Module &) {}
247 /// EmitEndOfAsmFile - This virtual method can be overridden by targets that
248 /// want to emit something at the end of their file.
249 virtual void EmitEndOfAsmFile(Module &) {}
251 /// EmitFunctionBodyStart - Targets can override this to emit stuff before
252 /// the first basic block in the function.
253 virtual void EmitFunctionBodyStart() {}
255 /// EmitFunctionBodyEnd - Targets can override this to emit stuff after
256 /// the last basic block in the function.
257 virtual void EmitFunctionBodyEnd() {}
259 /// EmitInstruction - Targets should implement this to emit instructions.
260 virtual void EmitInstruction(const MachineInstr *) {
261 llvm_unreachable("EmitInstruction not implemented");
264 virtual void EmitFunctionEntryLabel();
266 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
268 /// EmitXXStructor - Targets can override this to change how global
269 /// constants that are part of a C++ static/global constructor list are
271 virtual void EmitXXStructor(const Constant *CV) {
272 EmitGlobalConstant(CV);
275 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
276 /// exactly one predecessor and the control transfer mechanism between
277 /// the predecessor and this block is a fall-through.
279 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
281 //===------------------------------------------------------------------===//
282 // Symbol Lowering Routines.
283 //===------------------------------------------------------------------===//
286 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
287 /// temporary label with the specified stem and unique ID.
288 MCSymbol *GetTempSymbol(StringRef Name, unsigned ID) const;
290 /// GetTempSymbol - Return an assembler temporary label with the specified
292 MCSymbol *GetTempSymbol(StringRef Name) const;
295 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
296 /// global value name as its base, with the specified suffix, and where the
297 /// symbol is forced to have private linkage if ForcePrivate is true.
298 MCSymbol *GetSymbolWithGlobalValueBase(const GlobalValue *GV,
300 bool ForcePrivate = true) const;
302 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
304 MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;
306 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
307 MCSymbol *GetCPISymbol(unsigned CPID) const;
309 /// GetJTISymbol - Return the symbol for the specified jump table entry.
310 MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;
312 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
313 /// FIXME: privatize to AsmPrinter.
314 MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;
316 /// GetBlockAddressSymbol - Return the MCSymbol used to satisfy BlockAddress
317 /// uses of the specified basic block.
318 MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
319 MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;
321 //===------------------------------------------------------------------===//
322 // Emission Helper Routines.
323 //===------------------------------------------------------------------===//
325 /// printOffset - This is just convenient handler for printing offsets.
326 void printOffset(int64_t Offset, raw_ostream &OS) const;
328 /// EmitInt8 - Emit a byte directive and value.
330 void EmitInt8(int Value) const;
332 /// EmitInt16 - Emit a short directive and value.
334 void EmitInt16(int Value) const;
336 /// EmitInt32 - Emit a long directive and value.
338 void EmitInt32(int Value) const;
340 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
341 /// in bytes of the directive is specified by Size and Hi/Lo specify the
342 /// labels. This implicitly uses .set if it is available.
343 void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
344 unsigned Size) const;
346 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
347 /// where the size in bytes of the directive is specified by Size and Hi/Lo
348 /// specify the labels. This implicitly uses .set if it is available.
349 void EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
350 const MCSymbol *Lo, unsigned Size) const;
352 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
353 /// where the size in bytes of the directive is specified by Size and Label
354 /// specifies the label. This implicitly uses .set if it is available.
355 void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
356 unsigned Size) const;
358 /// EmitLabelReference - Emit something like ".long Label"
359 /// where the size in bytes of the directive is specified by Size and Label
360 /// specifies the label.
361 void EmitLabelReference(const MCSymbol *Label, unsigned Size) const {
362 EmitLabelPlusOffset(Label, 0, Size);
365 //===------------------------------------------------------------------===//
366 // Dwarf Emission Helper Routines
367 //===------------------------------------------------------------------===//
369 /// EmitSLEB128 - emit the specified signed leb128 value.
370 void EmitSLEB128(int Value, const char *Desc = 0) const;
372 /// EmitULEB128 - emit the specified unsigned leb128 value.
373 void EmitULEB128(unsigned Value, const char *Desc = 0,
374 unsigned PadTo = 0) const;
376 /// EmitCFAByte - Emit a .byte 42 directive for a DW_CFA_xxx value.
377 void EmitCFAByte(unsigned Val) const;
379 /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
380 /// encoding. If verbose assembly output is enabled, we output comments
381 /// describing the encoding. Desc is a string saying what the encoding is
382 /// specifying (e.g. "LSDA").
383 void EmitEncodingByte(unsigned Val, const char *Desc = 0) const;
385 /// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
386 unsigned GetSizeOfEncodedValue(unsigned Encoding) const;
388 /// EmitReference - Emit reference to a ttype global with a specified encoding.
389 void EmitTTypeReference(const GlobalValue *GV, unsigned Encoding) const;
391 /// EmitSectionOffset - Emit the 4-byte offset of Label from the start of
392 /// its section. This can be done with a special directive if the target
393 /// supports it (e.g. cygwin) or by emitting it as an offset from a label at
394 /// the start of the section.
396 /// SectionLabel is a temporary label emitted at the start of the section
397 /// that Label lives in.
398 void EmitSectionOffset(const MCSymbol *Label,
399 const MCSymbol *SectionLabel) const;
401 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
403 virtual MachineLocation getDebugValueLocation(const MachineInstr *MI) const;
405 /// getISAEncoding - Get the value for DW_AT_APPLE_isa. Zero if no isa
406 /// encoding specified.
407 virtual unsigned getISAEncoding() { return 0; }
409 /// EmitDwarfRegOp - Emit dwarf register operation.
410 virtual void EmitDwarfRegOp(const MachineLocation &MLoc) const;
412 //===------------------------------------------------------------------===//
413 // Dwarf Lowering Routines
414 //===------------------------------------------------------------------===//
416 /// EmitCFIFrameMove - Emit frame instruction to describe the layout of the
418 void EmitCFIFrameMove(const MachineMove &Move) const;
420 //===------------------------------------------------------------------===//
421 // Inline Asm Support
422 //===------------------------------------------------------------------===//
424 // These are hooks that targets can override to implement inline asm
425 // support. These should probably be moved out of AsmPrinter someday.
427 /// PrintSpecial - Print information related to the specified machine instr
428 /// that is independent of the operand, and may be independent of the instr
429 /// itself. This can be useful for portably encoding the comment character
430 /// or other bits of target-specific knowledge into the asmstrings. The
431 /// syntax used is ${:comment}. Targets can override this to add support
432 /// for their own strange codes.
433 virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
434 const char *Code) const;
436 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
437 /// instruction, using the specified assembler variant. Targets should
438 /// override this to format as appropriate. This method can return true if
439 /// the operand is erroneous.
440 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
441 unsigned AsmVariant, const char *ExtraCode,
444 /// PrintAsmMemoryOperand - Print the specified operand of MI, an INLINEASM
445 /// instruction, using the specified assembler variant as an address.
446 /// Targets should override this to format as appropriate. This method can
447 /// return true if the operand is erroneous.
448 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
450 const char *ExtraCode,
454 /// Private state for PrintSpecial()
455 // Assign a unique ID to this machine instruction.
456 mutable const MachineInstr *LastMI;
457 mutable unsigned LastFn;
458 mutable unsigned Counter;
459 mutable unsigned SetCounter;
461 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
462 void EmitInlineAsm(StringRef Str, const MDNode *LocMDNode = 0,
463 InlineAsm::AsmDialect AsmDialect = InlineAsm::AD_ATT) const;
465 /// EmitInlineAsm - This method formats and emits the specified machine
466 /// instruction that is an inline asm.
467 void EmitInlineAsm(const MachineInstr *MI) const;
469 //===------------------------------------------------------------------===//
470 // Internal Implementation Details
471 //===------------------------------------------------------------------===//
473 /// EmitVisibility - This emits visibility information about symbol, if
474 /// this is suported by the target.
475 void EmitVisibility(MCSymbol *Sym, unsigned Visibility,
476 bool IsDefinition = true) const;
478 void EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const;
480 void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
481 const MachineBasicBlock *MBB,
483 void EmitLLVMUsedList(const Constant *List);
484 void EmitXXStructorList(const Constant *List, bool isCtor);
485 GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);