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Andrew Scull5e1ddfa2018-08-14 10:06:54 +01001//===- 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/ADT/MapVector.h"
20#include "llvm/ADT/SmallVector.h"
21#include "llvm/ADT/StringRef.h"
22#include "llvm/ADT/Twine.h"
23#include "llvm/CodeGen/DwarfStringPoolEntry.h"
24#include "llvm/CodeGen/MachineFunctionPass.h"
25#include "llvm/IR/InlineAsm.h"
26#include "llvm/IR/LLVMContext.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/SourceMgr.h"
29#include <cstdint>
30#include <memory>
31#include <utility>
32#include <vector>
33
34namespace llvm {
35
36class AsmPrinterHandler;
37class BasicBlock;
38class BlockAddress;
39class Constant;
40class ConstantArray;
41class DataLayout;
42class DIE;
43class DIEAbbrev;
44class DwarfDebug;
45class GCMetadataPrinter;
46class GCStrategy;
47class GlobalIndirectSymbol;
48class GlobalObject;
49class GlobalValue;
50class GlobalVariable;
51class MachineBasicBlock;
52class MachineConstantPoolValue;
Andrew Scullcdfcccc2018-10-05 20:58:37 +010053class MachineDominatorTree;
Andrew Scull5e1ddfa2018-08-14 10:06:54 +010054class MachineFunction;
55class MachineInstr;
56class MachineJumpTableInfo;
57class MachineLoopInfo;
58class MachineModuleInfo;
59class MachineOptimizationRemarkEmitter;
60class MCAsmInfo;
61class MCCFIInstruction;
62struct MCCodePaddingContext;
63class MCContext;
64class MCExpr;
65class MCInst;
66class MCSection;
67class MCStreamer;
68class MCSubtargetInfo;
69class MCSymbol;
70class MCTargetOptions;
71class MDNode;
72class Module;
73class raw_ostream;
74class TargetLoweringObjectFile;
75class TargetMachine;
76
77/// This class is intended to be used as a driving class for all asm writers.
78class AsmPrinter : public MachineFunctionPass {
79public:
80 /// Target machine description.
81 TargetMachine &TM;
82
83 /// Target Asm Printer information.
84 const MCAsmInfo *MAI;
85
86 /// This is the context for the output file that we are streaming. This owns
87 /// all of the global MC-related objects for the generated translation unit.
88 MCContext &OutContext;
89
90 /// This is the MCStreamer object for the file we are generating. This
91 /// contains the transient state for the current translation unit that we are
92 /// generating (such as the current section etc).
93 std::unique_ptr<MCStreamer> OutStreamer;
94
95 /// The current machine function.
Andrew Scullcdfcccc2018-10-05 20:58:37 +010096 MachineFunction *MF = nullptr;
Andrew Scull5e1ddfa2018-08-14 10:06:54 +010097
98 /// This is a pointer to the current MachineModuleInfo.
99 MachineModuleInfo *MMI = nullptr;
100
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100101 /// This is a pointer to the current MachineLoopInfo.
102 MachineDominatorTree *MDT = nullptr;
103
104 /// This is a pointer to the current MachineLoopInfo.
105 MachineLoopInfo *MLI = nullptr;
106
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100107 /// Optimization remark emitter.
108 MachineOptimizationRemarkEmitter *ORE;
109
110 /// The symbol for the current function. This is recalculated at the beginning
111 /// of each call to runOnMachineFunction().
112 MCSymbol *CurrentFnSym = nullptr;
113
114 /// The symbol used to represent the start of the current function for the
115 /// purpose of calculating its size (e.g. using the .size directive). By
116 /// default, this is equal to CurrentFnSym.
117 MCSymbol *CurrentFnSymForSize = nullptr;
118
119 /// Map global GOT equivalent MCSymbols to GlobalVariables and keep track of
120 /// its number of uses by other globals.
121 using GOTEquivUsePair = std::pair<const GlobalVariable *, unsigned>;
122 MapVector<const MCSymbol *, GOTEquivUsePair> GlobalGOTEquivs;
123
124 /// Enable print [latency:throughput] in output.
125 bool EnablePrintSchedInfo = false;
126
127private:
128 MCSymbol *CurrentFnBegin = nullptr;
129 MCSymbol *CurrentFnEnd = nullptr;
130 MCSymbol *CurExceptionSym = nullptr;
131
132 // The garbage collection metadata printer table.
133 void *GCMetadataPrinters = nullptr; // Really a DenseMap.
134
135 /// Emit comments in assembly output if this is true.
136 bool VerboseAsm;
137
138 static char ID;
139
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100140 struct HandlerInfo {
141 AsmPrinterHandler *Handler;
142 const char *TimerName;
143 const char *TimerDescription;
144 const char *TimerGroupName;
145 const char *TimerGroupDescription;
146
147 HandlerInfo(AsmPrinterHandler *Handler, const char *TimerName,
148 const char *TimerDescription, const char *TimerGroupName,
149 const char *TimerGroupDescription)
150 : Handler(Handler), TimerName(TimerName),
151 TimerDescription(TimerDescription), TimerGroupName(TimerGroupName),
152 TimerGroupDescription(TimerGroupDescription) {}
153 };
154
155 /// A vector of all debug/EH info emitters we should use. This vector
156 /// maintains ownership of the emitters.
157 SmallVector<HandlerInfo, 1> Handlers;
158
159public:
160 struct SrcMgrDiagInfo {
161 SourceMgr SrcMgr;
162 std::vector<const MDNode *> LocInfos;
163 LLVMContext::InlineAsmDiagHandlerTy DiagHandler;
164 void *DiagContext;
165 };
166
167private:
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100168 /// If generated on the fly this own the instance.
169 std::unique_ptr<MachineDominatorTree> OwnedMDT;
170
171 /// If generated on the fly this own the instance.
172 std::unique_ptr<MachineLoopInfo> OwnedMLI;
173
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100174 /// Structure for generating diagnostics for inline assembly. Only initialised
175 /// when necessary.
176 mutable std::unique_ptr<SrcMgrDiagInfo> DiagInfo;
177
178 /// If the target supports dwarf debug info, this pointer is non-null.
179 DwarfDebug *DD = nullptr;
180
181 /// If the current module uses dwarf CFI annotations strictly for debugging.
182 bool isCFIMoveForDebugging = false;
183
184protected:
185 explicit AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer);
186
187public:
188 ~AsmPrinter() override;
189
190 DwarfDebug *getDwarfDebug() { return DD; }
191 DwarfDebug *getDwarfDebug() const { return DD; }
192
193 uint16_t getDwarfVersion() const;
194 void setDwarfVersion(uint16_t Version);
195
196 bool isPositionIndependent() const;
197
198 /// Return true if assembly output should contain comments.
199 bool isVerbose() const { return VerboseAsm; }
200
201 /// Return a unique ID for the current function.
202 unsigned getFunctionNumber() const;
203
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100204 /// Return symbol for the function pseudo stack if the stack frame is not a
205 /// register based.
206 virtual const MCSymbol *getFunctionFrameSymbol() const { return nullptr; }
207
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100208 MCSymbol *getFunctionBegin() const { return CurrentFnBegin; }
209 MCSymbol *getFunctionEnd() const { return CurrentFnEnd; }
210 MCSymbol *getCurExceptionSym();
211
212 /// Return information about object file lowering.
213 const TargetLoweringObjectFile &getObjFileLowering() const;
214
215 /// Return information about data layout.
216 const DataLayout &getDataLayout() const;
217
218 /// Return the pointer size from the TargetMachine
219 unsigned getPointerSize() const;
220
221 /// Return information about subtarget.
222 const MCSubtargetInfo &getSubtargetInfo() const;
223
224 void EmitToStreamer(MCStreamer &S, const MCInst &Inst);
225
226 /// Return the current section we are emitting to.
227 const MCSection *getCurrentSection() const;
228
229 void getNameWithPrefix(SmallVectorImpl<char> &Name,
230 const GlobalValue *GV) const;
231
232 MCSymbol *getSymbol(const GlobalValue *GV) const;
233
234 //===------------------------------------------------------------------===//
235 // XRay instrumentation implementation.
236 //===------------------------------------------------------------------===//
237public:
238 // This describes the kind of sled we're storing in the XRay table.
239 enum class SledKind : uint8_t {
240 FUNCTION_ENTER = 0,
241 FUNCTION_EXIT = 1,
242 TAIL_CALL = 2,
243 LOG_ARGS_ENTER = 3,
244 CUSTOM_EVENT = 4,
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100245 TYPED_EVENT = 5,
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100246 };
247
248 // The table will contain these structs that point to the sled, the function
249 // containing the sled, and what kind of sled (and whether they should always
250 // be instrumented). We also use a version identifier that the runtime can use
251 // to decide what to do with the sled, depending on the version of the sled.
252 struct XRayFunctionEntry {
253 const MCSymbol *Sled;
254 const MCSymbol *Function;
255 SledKind Kind;
256 bool AlwaysInstrument;
257 const class Function *Fn;
258 uint8_t Version;
259
260 void emit(int, MCStreamer *, const MCSymbol *) const;
261 };
262
263 // All the sleds to be emitted.
264 SmallVector<XRayFunctionEntry, 4> Sleds;
265
266 // A unique ID used for ELF sections associated with a particular function.
267 unsigned XRayFnUniqueID = 0;
268
269 // Helper function to record a given XRay sled.
270 void recordSled(MCSymbol *Sled, const MachineInstr &MI, SledKind Kind,
271 uint8_t Version = 0);
272
273 /// Emit a table with all XRay instrumentation points.
274 void emitXRayTable();
275
276 //===------------------------------------------------------------------===//
277 // MachineFunctionPass Implementation.
278 //===------------------------------------------------------------------===//
279
280 /// Record analysis usage.
281 void getAnalysisUsage(AnalysisUsage &AU) const override;
282
283 /// Set up the AsmPrinter when we are working on a new module. If your pass
284 /// overrides this, it must make sure to explicitly call this implementation.
285 bool doInitialization(Module &M) override;
286
287 /// Shut down the asmprinter. If you override this in your pass, you must make
288 /// sure to call it explicitly.
289 bool doFinalization(Module &M) override;
290
291 /// Emit the specified function out to the OutStreamer.
292 bool runOnMachineFunction(MachineFunction &MF) override {
293 SetupMachineFunction(MF);
294 EmitFunctionBody();
295 return false;
296 }
297
298 //===------------------------------------------------------------------===//
299 // Coarse grained IR lowering routines.
300 //===------------------------------------------------------------------===//
301
302 /// This should be called when a new MachineFunction is being processed from
303 /// runOnMachineFunction.
304 void SetupMachineFunction(MachineFunction &MF);
305
306 /// This method emits the body and trailer for a function.
307 void EmitFunctionBody();
308
309 void emitCFIInstruction(const MachineInstr &MI);
310
311 void emitFrameAlloc(const MachineInstr &MI);
312
313 void emitStackSizeSection(const MachineFunction &MF);
314
315 enum CFIMoveType { CFI_M_None, CFI_M_EH, CFI_M_Debug };
316 CFIMoveType needsCFIMoves() const;
317
318 /// Returns false if needsCFIMoves() == CFI_M_EH for any function
319 /// in the module.
320 bool needsOnlyDebugCFIMoves() const { return isCFIMoveForDebugging; }
321
322 bool needsSEHMoves();
323
324 /// Print to the current output stream assembly representations of the
325 /// constants in the constant pool MCP. This is used to print out constants
326 /// which have been "spilled to memory" by the code generator.
327 virtual void EmitConstantPool();
328
329 /// Print assembly representations of the jump tables used by the current
330 /// function to the current output stream.
331 virtual void EmitJumpTableInfo();
332
333 /// Emit the specified global variable to the .s file.
334 virtual void EmitGlobalVariable(const GlobalVariable *GV);
335
336 /// Check to see if the specified global is a special global used by LLVM. If
337 /// so, emit it and return true, otherwise do nothing and return false.
338 bool EmitSpecialLLVMGlobal(const GlobalVariable *GV);
339
340 /// Emit an alignment directive to the specified power of two boundary. For
341 /// example, if you pass in 3 here, you will get an 8 byte alignment. If a
342 /// global value is specified, and if that global has an explicit alignment
343 /// requested, it will override the alignment request if required for
344 /// correctness.
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100345 void EmitAlignment(unsigned NumBits, const GlobalObject *GV = nullptr) const;
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100346
347 /// Lower the specified LLVM Constant to an MCExpr.
348 virtual const MCExpr *lowerConstant(const Constant *CV);
349
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100350 /// Print a general LLVM constant to the .s file.
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100351 void EmitGlobalConstant(const DataLayout &DL, const Constant *CV);
352
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100353 /// Unnamed constant global variables solely contaning a pointer to
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100354 /// another globals variable act like a global variable "proxy", or GOT
355 /// equivalents, i.e., it's only used to hold the address of the latter. One
356 /// optimization is to replace accesses to these proxies by using the GOT
357 /// entry for the final global instead. Hence, we select GOT equivalent
358 /// candidates among all the module global variables, avoid emitting them
359 /// unnecessarily and finally replace references to them by pc relative
360 /// accesses to GOT entries.
361 void computeGlobalGOTEquivs(Module &M);
362
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100363 /// Constant expressions using GOT equivalent globals may not be
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100364 /// eligible for PC relative GOT entry conversion, in such cases we need to
365 /// emit the proxies we previously omitted in EmitGlobalVariable.
366 void emitGlobalGOTEquivs();
367
368 //===------------------------------------------------------------------===//
369 // Overridable Hooks
370 //===------------------------------------------------------------------===//
371
372 // Targets can, or in the case of EmitInstruction, must implement these to
373 // customize output.
374
375 /// This virtual method can be overridden by targets that want to emit
376 /// something at the start of their file.
377 virtual void EmitStartOfAsmFile(Module &) {}
378
379 /// This virtual method can be overridden by targets that want to emit
380 /// something at the end of their file.
381 virtual void EmitEndOfAsmFile(Module &) {}
382
383 /// Targets can override this to emit stuff before the first basic block in
384 /// the function.
385 virtual void EmitFunctionBodyStart() {}
386
387 /// Targets can override this to emit stuff after the last basic block in the
388 /// function.
389 virtual void EmitFunctionBodyEnd() {}
390
391 /// Targets can override this to emit stuff at the start of a basic block.
392 /// By default, this method prints the label for the specified
393 /// MachineBasicBlock, an alignment (if present) and a comment describing it
394 /// if appropriate.
395 virtual void EmitBasicBlockStart(const MachineBasicBlock &MBB) const;
396
397 /// Targets can override this to emit stuff at the end of a basic block.
398 virtual void EmitBasicBlockEnd(const MachineBasicBlock &MBB);
399
400 /// Targets should implement this to emit instructions.
401 virtual void EmitInstruction(const MachineInstr *) {
402 llvm_unreachable("EmitInstruction not implemented");
403 }
404
405 /// Return the symbol for the specified constant pool entry.
406 virtual MCSymbol *GetCPISymbol(unsigned CPID) const;
407
408 virtual void EmitFunctionEntryLabel();
409
410 virtual void EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV);
411
412 /// Targets can override this to change how global constants that are part of
413 /// a C++ static/global constructor list are emitted.
414 virtual void EmitXXStructor(const DataLayout &DL, const Constant *CV) {
415 EmitGlobalConstant(DL, CV);
416 }
417
418 /// Return true if the basic block has exactly one predecessor and the control
419 /// transfer mechanism between the predecessor and this block is a
420 /// fall-through.
421 virtual bool
422 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
423
424 /// Targets can override this to customize the output of IMPLICIT_DEF
425 /// instructions in verbose mode.
426 virtual void emitImplicitDef(const MachineInstr *MI) const;
427
428 //===------------------------------------------------------------------===//
429 // Symbol Lowering Routines.
430 //===------------------------------------------------------------------===//
431
432 MCSymbol *createTempSymbol(const Twine &Name) const;
433
434 /// Return the MCSymbol for a private symbol with global value name as its
435 /// base, with the specified suffix.
436 MCSymbol *getSymbolWithGlobalValueBase(const GlobalValue *GV,
437 StringRef Suffix) const;
438
439 /// Return the MCSymbol for the specified ExternalSymbol.
440 MCSymbol *GetExternalSymbolSymbol(StringRef Sym) const;
441
442 /// Return the symbol for the specified jump table entry.
443 MCSymbol *GetJTISymbol(unsigned JTID, bool isLinkerPrivate = false) const;
444
445 /// Return the symbol for the specified jump table .set
446 /// FIXME: privatize to AsmPrinter.
447 MCSymbol *GetJTSetSymbol(unsigned UID, unsigned MBBID) const;
448
449 /// Return the MCSymbol used to satisfy BlockAddress uses of the specified
450 /// basic block.
451 MCSymbol *GetBlockAddressSymbol(const BlockAddress *BA) const;
452 MCSymbol *GetBlockAddressSymbol(const BasicBlock *BB) const;
453
454 //===------------------------------------------------------------------===//
455 // Emission Helper Routines.
456 //===------------------------------------------------------------------===//
457
458 /// This is just convenient handler for printing offsets.
459 void printOffset(int64_t Offset, raw_ostream &OS) const;
460
461 /// Emit a byte directive and value.
462 void emitInt8(int Value) const;
463
464 /// Emit a short directive and value.
465 void emitInt16(int Value) const;
466
467 /// Emit a long directive and value.
468 void emitInt32(int Value) const;
469
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100470 /// Emit a long long directive and value.
471 void emitInt64(uint64_t Value) const;
472
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100473 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
474 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
475 /// .set if it is available.
476 void EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
477 unsigned Size) const;
478
479 /// Emit something like ".uleb128 Hi-Lo".
480 void EmitLabelDifferenceAsULEB128(const MCSymbol *Hi,
481 const MCSymbol *Lo) const;
482
483 /// Emit something like ".long Label+Offset" where the size in bytes of the
484 /// directive is specified by Size and Label specifies the label. This
485 /// implicitly uses .set if it is available.
486 void EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
487 unsigned Size, bool IsSectionRelative = false) const;
488
489 /// Emit something like ".long Label" where the size in bytes of the directive
490 /// is specified by Size and Label specifies the label.
491 void EmitLabelReference(const MCSymbol *Label, unsigned Size,
492 bool IsSectionRelative = false) const {
493 EmitLabelPlusOffset(Label, 0, Size, IsSectionRelative);
494 }
495
496 /// Emit something like ".long Label + Offset".
497 void EmitDwarfOffset(const MCSymbol *Label, uint64_t Offset) const;
498
499 //===------------------------------------------------------------------===//
500 // Dwarf Emission Helper Routines
501 //===------------------------------------------------------------------===//
502
503 /// Emit the specified signed leb128 value.
504 void EmitSLEB128(int64_t Value, const char *Desc = nullptr) const;
505
506 /// Emit the specified unsigned leb128 value.
507 void EmitULEB128(uint64_t Value, const char *Desc = nullptr) const;
508
509 /// Emit a .byte 42 directive that corresponds to an encoding. If verbose
510 /// assembly output is enabled, we output comments describing the encoding.
511 /// Desc is a string saying what the encoding is specifying (e.g. "LSDA").
512 void EmitEncodingByte(unsigned Val, const char *Desc = nullptr) const;
513
514 /// Return the size of the encoding in bytes.
515 unsigned GetSizeOfEncodedValue(unsigned Encoding) const;
516
517 /// Emit reference to a ttype global with a specified encoding.
518 void EmitTTypeReference(const GlobalValue *GV, unsigned Encoding) const;
519
520 /// Emit a reference to a symbol for use in dwarf. Different object formats
521 /// represent this in different ways. Some use a relocation others encode
522 /// the label offset in its section.
523 void emitDwarfSymbolReference(const MCSymbol *Label,
524 bool ForceOffset = false) const;
525
526 /// Emit the 4-byte offset of a string from the start of its section.
527 ///
528 /// When possible, emit a DwarfStringPool section offset without any
529 /// relocations, and without using the symbol. Otherwise, defers to \a
530 /// emitDwarfSymbolReference().
531 void emitDwarfStringOffset(DwarfStringPoolEntry S) const;
532
533 /// Emit the 4-byte offset of a string from the start of its section.
534 void emitDwarfStringOffset(DwarfStringPoolEntryRef S) const {
535 emitDwarfStringOffset(S.getEntry());
536 }
537
538 /// Get the value for DW_AT_APPLE_isa. Zero if no isa encoding specified.
539 virtual unsigned getISAEncoding() { return 0; }
540
541 /// Emit the directive and value for debug thread local expression
542 ///
543 /// \p Value - The value to emit.
544 /// \p Size - The size of the integer (in bytes) to emit.
545 virtual void EmitDebugThreadLocal(const MCExpr *Value, unsigned Size) const;
546
547 //===------------------------------------------------------------------===//
548 // Dwarf Lowering Routines
549 //===------------------------------------------------------------------===//
550
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100551 /// Emit frame instruction to describe the layout of the frame.
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100552 void emitCFIInstruction(const MCCFIInstruction &Inst) const;
553
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100554 /// Emit Dwarf abbreviation table.
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100555 template <typename T> void emitDwarfAbbrevs(const T &Abbrevs) const {
556 // For each abbreviation.
557 for (const auto &Abbrev : Abbrevs)
558 emitDwarfAbbrev(*Abbrev);
559
560 // Mark end of abbreviations.
561 EmitULEB128(0, "EOM(3)");
562 }
563
564 void emitDwarfAbbrev(const DIEAbbrev &Abbrev) const;
565
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100566 /// Recursively emit Dwarf DIE tree.
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100567 void emitDwarfDIE(const DIE &Die) const;
568
569 //===------------------------------------------------------------------===//
570 // Inline Asm Support
571 //===------------------------------------------------------------------===//
572
573 // These are hooks that targets can override to implement inline asm
574 // support. These should probably be moved out of AsmPrinter someday.
575
576 /// Print information related to the specified machine instr that is
577 /// independent of the operand, and may be independent of the instr itself.
578 /// This can be useful for portably encoding the comment character or other
579 /// bits of target-specific knowledge into the asmstrings. The syntax used is
580 /// ${:comment}. Targets can override this to add support for their own
581 /// strange codes.
582 virtual void PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
583 const char *Code) const;
584
585 /// Print the specified operand of MI, an INLINEASM instruction, using the
586 /// specified assembler variant. Targets should override this to format as
587 /// appropriate. This method can return true if the operand is erroneous.
588 virtual bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
589 unsigned AsmVariant, const char *ExtraCode,
590 raw_ostream &OS);
591
592 /// Print the specified operand of MI, an INLINEASM instruction, using the
593 /// specified assembler variant as an address. Targets should override this to
594 /// format as appropriate. This method can return true if the operand is
595 /// erroneous.
596 virtual bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
597 unsigned AsmVariant, const char *ExtraCode,
598 raw_ostream &OS);
599
600 /// Let the target do anything it needs to do before emitting inlineasm.
601 /// \p StartInfo - the subtarget info before parsing inline asm
602 virtual void emitInlineAsmStart() const;
603
604 /// Let the target do anything it needs to do after emitting inlineasm.
605 /// This callback can be used restore the original mode in case the
606 /// inlineasm contains directives to switch modes.
607 /// \p StartInfo - the original subtarget info before inline asm
608 /// \p EndInfo - the final subtarget info after parsing the inline asm,
609 /// or NULL if the value is unknown.
610 virtual void emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
611 const MCSubtargetInfo *EndInfo) const;
612
613private:
614 /// Private state for PrintSpecial()
615 // Assign a unique ID to this machine instruction.
616 mutable const MachineInstr *LastMI = nullptr;
617 mutable unsigned LastFn = 0;
618 mutable unsigned Counter = ~0U;
619
620 /// This method emits the header for the current function.
621 virtual void EmitFunctionHeader();
622
623 /// Emit a blob of inline asm to the output streamer.
624 void
625 EmitInlineAsm(StringRef Str, const MCSubtargetInfo &STI,
626 const MCTargetOptions &MCOptions,
627 const MDNode *LocMDNode = nullptr,
628 InlineAsm::AsmDialect AsmDialect = InlineAsm::AD_ATT) const;
629
630 /// This method formats and emits the specified machine instruction that is an
631 /// inline asm.
632 void EmitInlineAsm(const MachineInstr *MI) const;
633
Andrew Scull0372a572018-11-16 15:47:06 +0000634 /// Add inline assembly info to the diagnostics machinery, so we can
635 /// emit file and position info. Returns SrcMgr memory buffer position.
636 unsigned addInlineAsmDiagBuffer(StringRef AsmStr,
637 const MDNode *LocMDNode) const;
638
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100639 //===------------------------------------------------------------------===//
640 // Internal Implementation Details
641 //===------------------------------------------------------------------===//
642
643 /// This emits visibility information about symbol, if this is supported by
644 /// the target.
645 void EmitVisibility(MCSymbol *Sym, unsigned Visibility,
646 bool IsDefinition = true) const;
647
648 void EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const;
649
650 void EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
651 const MachineBasicBlock *MBB, unsigned uid) const;
652 void EmitLLVMUsedList(const ConstantArray *InitList);
653 /// Emit llvm.ident metadata in an '.ident' directive.
654 void EmitModuleIdents(Module &M);
655 void EmitXXStructorList(const DataLayout &DL, const Constant *List,
656 bool isCtor);
657
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100658 GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy &S);
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100659 /// Emit GlobalAlias or GlobalIFunc.
Andrew Scullcdfcccc2018-10-05 20:58:37 +0100660 void emitGlobalIndirectSymbol(Module &M, const GlobalIndirectSymbol &GIS);
Andrew Scull5e1ddfa2018-08-14 10:06:54 +0100661 void setupCodePaddingContext(const MachineBasicBlock &MBB,
662 MCCodePaddingContext &Context) const;
663};
664
665} // end namespace llvm
666
667#endif // LLVM_CODEGEN_ASMPRINTER_H