1//===- llvm/Function.h - Class to represent a single function ---*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains the declaration of the Function class, which represents a
10// single function/procedure in LLVM.
11//
12// A function basically consists of a list of basic blocks, a list of arguments,
13// and a symbol table.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_IR_FUNCTION_H
18#define LLVM_IR_FUNCTION_H
19
20#include "llvm/ADT/DenseSet.h"
21#include "llvm/ADT/StringRef.h"
22#include "llvm/ADT/Twine.h"
23#include "llvm/ADT/ilist_node.h"
24#include "llvm/ADT/iterator_range.h"
25#include "llvm/IR/Argument.h"
26#include "llvm/IR/Attributes.h"
27#include "llvm/IR/BasicBlock.h"
28#include "llvm/IR/CallingConv.h"
29#include "llvm/IR/DerivedTypes.h"
30#include "llvm/IR/GlobalObject.h"
31#include "llvm/IR/GlobalValue.h"
32#include "llvm/IR/OperandTraits.h"
33#include "llvm/IR/SymbolTableListTraits.h"
34#include "llvm/IR/Value.h"
35#include "llvm/Support/Compiler.h"
36#include <cassert>
37#include <cstddef>
38#include <cstdint>
39#include <memory>
40#include <string>
41
42namespace llvm {
43
44namespace Intrinsic {
45typedef unsigned ID;
46}
47
48class AssemblyAnnotationWriter;
49class Constant;
50class ConstantRange;
51class DataLayout;
52struct DenormalMode;
53class DISubprogram;
54enum LibFunc : unsigned;
55class LLVMContext;
56class Module;
57class raw_ostream;
58class TargetLibraryInfoImpl;
59class Type;
60class User;
61class BranchProbabilityInfo;
62class BlockFrequencyInfo;
63
64class LLVM_ABI Function : public GlobalObject, public ilist_node<Function> {
65public:
66 using BasicBlockListType = SymbolTableList<BasicBlock>;
67
68 // BasicBlock iterators...
69 using iterator = BasicBlockListType::iterator;
70 using const_iterator = BasicBlockListType::const_iterator;
71
72 using arg_iterator = Argument *;
73 using const_arg_iterator = const Argument *;
74
75private:
76 constexpr static HungOffOperandsAllocMarker AllocMarker{};
77
78 // Important things that make up a function!
79 BasicBlockListType BasicBlocks; ///< The basic blocks
80
81 // Basic blocks need to get their number when added to a function.
82 friend void BasicBlock::setParent(Function *);
83 unsigned NextBlockNum = 0;
84 /// Epoch of block numbers. (Could be shrinked to uint8_t if required.)
85 unsigned BlockNumEpoch = 0;
86
87 mutable Argument *Arguments = nullptr; ///< The formal arguments
88 size_t NumArgs;
89 std::unique_ptr<ValueSymbolTable>
90 SymTab; ///< Symbol table of args/instructions
91 AttributeList AttributeSets; ///< Parameter attributes
92
93 /*
94 * Value::SubclassData
95 *
96 * bit 0 : HasLazyArguments
97 * bit 1 : HasPrefixData
98 * bit 2 : HasPrologueData
99 * bit 3 : HasPersonalityFn
100 * bits 4-13 : CallingConvention
101 * bits 14 : HasGC
102 * bits 15 : [reserved]
103 */
104
105 /// Bits from GlobalObject::GlobalObjectSubclassData.
106 enum {
107 /// Whether this function is materializable.
108 IsMaterializableBit = 0,
109 };
110
111 friend class SymbolTableListTraits<Function>;
112
113public:
114 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
115 /// built on demand, so that the list isn't allocated until the first client
116 /// needs it. The hasLazyArguments predicate returns true if the arg list
117 /// hasn't been set up yet.
118 bool hasLazyArguments() const {
119 return getSubclassDataFromValue() & (1<<0);
120 }
121
122 /// \see BasicBlock::convertToNewDbgValues.
123 void convertToNewDbgValues();
124
125 /// \see BasicBlock::convertFromNewDbgValues.
126 void convertFromNewDbgValues();
127
128private:
129 friend class TargetLibraryInfoImpl;
130
131 static constexpr LibFunc UnknownLibFunc = LibFunc(-1);
132
133 /// Cache for TLI::getLibFunc() result without prototype validation.
134 /// UnknownLibFunc if uninitialized. NotLibFunc if definitely not lib func.
135 /// Otherwise may be libfunc if prototype validation passes.
136 mutable LibFunc LibFuncCache = UnknownLibFunc;
137
138 void CheckLazyArguments() const {
139 if (hasLazyArguments())
140 BuildLazyArguments();
141 }
142
143 void BuildLazyArguments() const;
144
145 void clearArguments();
146
147 void deleteBodyImpl(bool ShouldDrop);
148
149 /// Function ctor - If the (optional) Module argument is specified, the
150 /// function is automatically inserted into the end of the function list for
151 /// the module.
152 ///
153 Function(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace,
154 const Twine &N = "", Module *M = nullptr);
155
156public:
157 Function(const Function&) = delete;
158 void operator=(const Function&) = delete;
159 ~Function();
160
161 // This is here to help easily convert from FunctionT * (Function * or
162 // MachineFunction *) in BlockFrequencyInfoImpl to Function * by calling
163 // FunctionT->getFunction().
164 const Function &getFunction() const { return *this; }
165
166 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
167 unsigned AddrSpace, const Twine &N = "",
168 Module *M = nullptr) {
169 return new (AllocMarker) Function(Ty, Linkage, AddrSpace, N, M);
170 }
171
172 // TODO: remove this once all users have been updated to pass an AddrSpace
173 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
174 const Twine &N = "", Module *M = nullptr) {
175 return new (AllocMarker)
176 Function(Ty, Linkage, static_cast<unsigned>(-1), N, M);
177 }
178
179 /// Creates a new function and attaches it to a module.
180 ///
181 /// Places the function in the program address space as specified
182 /// by the module's data layout.
183 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
184 const Twine &N, Module &M);
185
186 /// Creates a function with some attributes recorded in llvm.module.flags
187 /// and the LLVMContext applied.
188 ///
189 /// Use this when synthesizing new functions that need attributes that would
190 /// have been set by command line options.
191 ///
192 /// This function should not be called from backends or the LTO pipeline. If
193 /// it is called from one of those places, some default attributes will not be
194 /// applied to the function.
195 static Function *createWithDefaultAttr(FunctionType *Ty, LinkageTypes Linkage,
196 unsigned AddrSpace,
197 const Twine &N = "",
198 Module *M = nullptr);
199
200 // Provide fast operand accessors.
201 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
202
203 /// Returns the number of non-debug IR instructions in this function.
204 /// This is equivalent to the sum of the sizes of each basic block contained
205 /// within this function.
206 unsigned getInstructionCount() const;
207
208 /// Returns the FunctionType for me.
209 FunctionType *getFunctionType() const {
210 return cast<FunctionType>(Val: getValueType());
211 }
212
213 /// Returns the type of the ret val.
214 Type *getReturnType() const { return getFunctionType()->getReturnType(); }
215
216 /// getContext - Return a reference to the LLVMContext associated with this
217 /// function.
218 LLVMContext &getContext() const;
219
220 /// Get the data layout of the module this function belongs to.
221 ///
222 /// Requires the function to have a parent module.
223 const DataLayout &getDataLayout() const;
224
225 /// isVarArg - Return true if this function takes a variable number of
226 /// arguments.
227 bool isVarArg() const { return getFunctionType()->isVarArg(); }
228
229 bool isMaterializable() const {
230 return getGlobalObjectSubClassData() & (1 << IsMaterializableBit);
231 }
232 void setIsMaterializable(bool V) {
233 unsigned Mask = 1 << IsMaterializableBit;
234 setGlobalObjectSubClassData((~Mask & getGlobalObjectSubClassData()) |
235 (V ? Mask : 0u));
236 }
237
238 /// getIntrinsicID - This method returns the ID number of the specified
239 /// function, or Intrinsic::not_intrinsic if the function is not an
240 /// intrinsic, or if the pointer is null. This value is always defined to be
241 /// zero to allow easy checking for whether a function is intrinsic or not.
242 /// The particular intrinsic functions which correspond to this value are
243 /// defined in llvm/Intrinsics.h.
244 Intrinsic::ID getIntrinsicID() const LLVM_READONLY { return IntID; }
245
246 /// isIntrinsic - Returns true if the function's name starts with "llvm.".
247 /// It's possible for this function to return true while getIntrinsicID()
248 /// returns Intrinsic::not_intrinsic!
249 bool isIntrinsic() const { return HasLLVMReservedName; }
250
251 /// isTargetIntrinsic - Returns true if this function is an intrinsic and the
252 /// intrinsic is specific to a certain target. If this is not an intrinsic
253 /// or a generic intrinsic, false is returned.
254 bool isTargetIntrinsic() const;
255
256 /// Returns true if the function is one of the "Constrained Floating-Point
257 /// Intrinsics". Returns false if not, and returns false when
258 /// getIntrinsicID() returns Intrinsic::not_intrinsic.
259 bool isConstrainedFPIntrinsic() const;
260
261 /// Update internal caches that depend on the function name (such as the
262 /// intrinsic ID and libcall cache).
263 /// Note, this method does not need to be called directly, as it is called
264 /// from Value::setName() whenever the name of this function changes.
265 void updateAfterNameChange();
266
267 /// getCallingConv()/setCallingConv(CC) - These method get and set the
268 /// calling convention of this function. The enum values for the known
269 /// calling conventions are defined in CallingConv.h.
270 CallingConv::ID getCallingConv() const {
271 return static_cast<CallingConv::ID>((getSubclassDataFromValue() >> 4) &
272 CallingConv::MaxID);
273 }
274 void setCallingConv(CallingConv::ID CC) {
275 auto ID = static_cast<unsigned>(CC);
276 assert(!(ID & ~CallingConv::MaxID) && "Unsupported calling convention");
277 setValueSubclassData((getSubclassDataFromValue() & 0xc00f) | (ID << 4));
278 }
279
280 /// Does it have a kernel calling convention?
281 bool hasKernelCallingConv() const {
282 switch (getCallingConv()) {
283 default:
284 return false;
285 case CallingConv::PTX_Kernel:
286 case CallingConv::AMDGPU_KERNEL:
287 case CallingConv::SPIR_KERNEL:
288 return true;
289 }
290 }
291
292 enum ProfileCountType { PCT_Real, PCT_Synthetic };
293
294 /// Class to represent profile counts.
295 ///
296 /// This class represents both real and synthetic profile counts.
297 class ProfileCount {
298 private:
299 uint64_t Count = 0;
300 ProfileCountType PCT = PCT_Real;
301
302 public:
303 ProfileCount(uint64_t Count, ProfileCountType PCT)
304 : Count(Count), PCT(PCT) {}
305 uint64_t getCount() const { return Count; }
306 ProfileCountType getType() const { return PCT; }
307 bool isSynthetic() const { return PCT == PCT_Synthetic; }
308 };
309
310 /// Set the entry count for this function.
311 ///
312 /// Entry count is the number of times this function was executed based on
313 /// pgo data. \p Imports points to a set of GUIDs that needs to
314 /// be imported by the function for sample PGO, to enable the same inlines as
315 /// the profiled optimized binary.
316 void setEntryCount(ProfileCount Count,
317 const DenseSet<GlobalValue::GUID> *Imports = nullptr);
318
319 /// A convenience wrapper for setting entry count
320 void setEntryCount(uint64_t Count, ProfileCountType Type = PCT_Real,
321 const DenseSet<GlobalValue::GUID> *Imports = nullptr);
322
323 /// Get the entry count for this function.
324 ///
325 /// Entry count is the number of times the function was executed.
326 /// When AllowSynthetic is false, only pgo_data will be returned.
327 std::optional<ProfileCount> getEntryCount(bool AllowSynthetic = false) const;
328
329 /// Return true if the function is annotated with profile data.
330 ///
331 /// Presence of entry counts from a profile run implies the function has
332 /// profile annotations. If IncludeSynthetic is false, only return true
333 /// when the profile data is real.
334 bool hasProfileData(bool IncludeSynthetic = false) const {
335 return getEntryCount(AllowSynthetic: IncludeSynthetic).has_value();
336 }
337
338 /// Returns the set of GUIDs that needs to be imported to the function for
339 /// sample PGO, to enable the same inlines as the profiled optimized binary.
340 DenseSet<GlobalValue::GUID> getImportGUIDs() const;
341
342 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
343 /// to use during code generation.
344 bool hasGC() const {
345 return getSubclassDataFromValue() & (1<<14);
346 }
347 const std::string &getGC() const;
348 void setGC(std::string Str);
349 void clearGC();
350
351 /// Return the attribute list for this Function.
352 AttributeList getAttributes() const { return AttributeSets; }
353
354 /// Set the attribute list for this Function.
355 void setAttributes(AttributeList Attrs) { AttributeSets = Attrs; }
356
357 // TODO: remove non-AtIndex versions of these methods.
358 /// adds the attribute to the list of attributes.
359 void addAttributeAtIndex(unsigned i, Attribute Attr);
360
361 /// Add function attributes to this function.
362 void addFnAttr(Attribute::AttrKind Kind);
363
364 /// Add function attributes to this function.
365 void addFnAttr(StringRef Kind, StringRef Val = StringRef());
366
367 /// Add function attributes to this function.
368 void addFnAttr(Attribute Attr);
369
370 /// Add function attributes to this function.
371 void addFnAttrs(const AttrBuilder &Attrs);
372
373 /// Add return value attributes to this function.
374 void addRetAttr(Attribute::AttrKind Kind);
375
376 /// Add return value attributes to this function.
377 void addRetAttr(Attribute Attr);
378
379 /// Add return value attributes to this function.
380 void addRetAttrs(const AttrBuilder &Attrs);
381
382 /// adds the attribute to the list of attributes for the given arg.
383 void addParamAttr(unsigned ArgNo, Attribute::AttrKind Kind);
384
385 /// adds the attribute to the list of attributes for the given arg.
386 void addParamAttr(unsigned ArgNo, Attribute Attr);
387
388 /// adds the attributes to the list of attributes for the given arg.
389 void addParamAttrs(unsigned ArgNo, const AttrBuilder &Attrs);
390
391 /// removes the attribute from the list of attributes.
392 void removeAttributeAtIndex(unsigned i, Attribute::AttrKind Kind);
393
394 /// removes the attribute from the list of attributes.
395 void removeAttributeAtIndex(unsigned i, StringRef Kind);
396
397 /// Remove function attributes from this function.
398 void removeFnAttr(Attribute::AttrKind Kind);
399
400 /// Remove function attribute from this function.
401 void removeFnAttr(StringRef Kind);
402
403 void removeFnAttrs(const AttributeMask &Attrs);
404
405 /// removes the attribute from the return value list of attributes.
406 void removeRetAttr(Attribute::AttrKind Kind);
407
408 /// removes the attribute from the return value list of attributes.
409 void removeRetAttr(StringRef Kind);
410
411 /// removes the attributes from the return value list of attributes.
412 void removeRetAttrs(const AttributeMask &Attrs);
413
414 /// removes the attribute from the list of attributes.
415 void removeParamAttr(unsigned ArgNo, Attribute::AttrKind Kind);
416
417 /// removes the attribute from the list of attributes.
418 void removeParamAttr(unsigned ArgNo, StringRef Kind);
419
420 /// removes the attribute from the list of attributes.
421 void removeParamAttrs(unsigned ArgNo, const AttributeMask &Attrs);
422
423 /// Return true if the function has the attribute.
424 bool hasFnAttribute(Attribute::AttrKind Kind) const;
425
426 /// Return true if the function has the attribute.
427 bool hasFnAttribute(StringRef Kind) const;
428
429 /// check if an attribute is in the list of attributes for the return value.
430 bool hasRetAttribute(Attribute::AttrKind Kind) const;
431
432 /// check if an attributes is in the list of attributes.
433 bool hasParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const;
434
435 /// Check if an attribute is in the list of attributes.
436 bool hasParamAttribute(unsigned ArgNo, StringRef Kind) const;
437
438 /// gets the attribute from the list of attributes.
439 Attribute getAttributeAtIndex(unsigned i, Attribute::AttrKind Kind) const;
440
441 /// gets the attribute from the list of attributes.
442 Attribute getAttributeAtIndex(unsigned i, StringRef Kind) const;
443
444 /// Check if attribute of the given kind is set at the given index.
445 bool hasAttributeAtIndex(unsigned Idx, Attribute::AttrKind Kind) const;
446
447 /// Return the attribute for the given attribute kind.
448 Attribute getFnAttribute(Attribute::AttrKind Kind) const;
449
450 /// Return the attribute for the given attribute kind.
451 Attribute getFnAttribute(StringRef Kind) const;
452
453 /// Return the attribute for the given attribute kind for the return value.
454 Attribute getRetAttribute(Attribute::AttrKind Kind) const;
455
456 /// For a string attribute \p Kind, parse attribute as an integer.
457 ///
458 /// \returns \p Default if attribute is not present.
459 ///
460 /// \returns \p Default if there is an error parsing the attribute integer,
461 /// and error is emitted to the LLVMContext
462 uint64_t getFnAttributeAsParsedInteger(StringRef Kind,
463 uint64_t Default = 0) const;
464
465 /// gets the specified attribute from the list of attributes.
466 Attribute getParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const;
467
468 /// Return the stack alignment for the function.
469 MaybeAlign getFnStackAlign() const {
470 return AttributeSets.getFnStackAlignment();
471 }
472
473 /// Returns true if the function has ssp, sspstrong, or sspreq fn attrs.
474 bool hasStackProtectorFnAttr() const;
475
476 /// adds the dereferenceable attribute to the list of attributes for
477 /// the given arg.
478 void addDereferenceableParamAttr(unsigned ArgNo, uint64_t Bytes);
479
480 /// adds the dereferenceable_or_null attribute to the list of
481 /// attributes for the given arg.
482 void addDereferenceableOrNullParamAttr(unsigned ArgNo, uint64_t Bytes);
483
484 /// adds the range attribute to the list of attributes for the return value.
485 void addRangeRetAttr(const ConstantRange &CR);
486
487 MaybeAlign getParamAlign(unsigned ArgNo) const {
488 return AttributeSets.getParamAlignment(ArgNo);
489 }
490
491 MaybeAlign getParamStackAlign(unsigned ArgNo) const {
492 return AttributeSets.getParamStackAlignment(ArgNo);
493 }
494
495 /// Extract the byval type for a parameter.
496 Type *getParamByValType(unsigned ArgNo) const {
497 return AttributeSets.getParamByValType(ArgNo);
498 }
499
500 /// Extract the sret type for a parameter.
501 Type *getParamStructRetType(unsigned ArgNo) const {
502 return AttributeSets.getParamStructRetType(ArgNo);
503 }
504
505 /// Extract the inalloca type for a parameter.
506 Type *getParamInAllocaType(unsigned ArgNo) const {
507 return AttributeSets.getParamInAllocaType(ArgNo);
508 }
509
510 /// Extract the byref type for a parameter.
511 Type *getParamByRefType(unsigned ArgNo) const {
512 return AttributeSets.getParamByRefType(ArgNo);
513 }
514
515 /// Extract the preallocated type for a parameter.
516 Type *getParamPreallocatedType(unsigned ArgNo) const {
517 return AttributeSets.getParamPreallocatedType(ArgNo);
518 }
519
520 /// Extract the number of dereferenceable bytes for a parameter.
521 /// @param ArgNo Index of an argument, with 0 being the first function arg.
522 uint64_t getParamDereferenceableBytes(unsigned ArgNo) const {
523 return AttributeSets.getParamDereferenceableBytes(Index: ArgNo);
524 }
525
526 /// Extract the number of dead_on_return bytes for a parameter.
527 /// @param ArgNo Index of an argument, with 0 being the first function arg.
528 DeadOnReturnInfo getDeadOnReturnInfo(unsigned ArgNo) const {
529 return AttributeSets.getDeadOnReturnInfo(Index: ArgNo);
530 }
531
532 /// Extract the number of dereferenceable_or_null bytes for a
533 /// parameter.
534 /// @param ArgNo AttributeList ArgNo, referring to an argument.
535 uint64_t getParamDereferenceableOrNullBytes(unsigned ArgNo) const {
536 return AttributeSets.getParamDereferenceableOrNullBytes(ArgNo);
537 }
538
539 /// Extract the nofpclass attribute for a parameter.
540 FPClassTest getParamNoFPClass(unsigned ArgNo) const {
541 return AttributeSets.getParamNoFPClass(ArgNo);
542 }
543
544 /// Determine if the function is presplit coroutine.
545 bool isPresplitCoroutine() const {
546 return hasFnAttribute(Kind: Attribute::PresplitCoroutine);
547 }
548 void setPresplitCoroutine() { addFnAttr(Kind: Attribute::PresplitCoroutine); }
549 void setSplittedCoroutine() { removeFnAttr(Kind: Attribute::PresplitCoroutine); }
550
551 bool isCoroOnlyDestroyWhenComplete() const {
552 return hasFnAttribute(Kind: Attribute::CoroDestroyOnlyWhenComplete);
553 }
554 void setCoroDestroyOnlyWhenComplete() {
555 addFnAttr(Kind: Attribute::CoroDestroyOnlyWhenComplete);
556 }
557
558 MemoryEffects getMemoryEffects() const;
559 void setMemoryEffects(MemoryEffects ME);
560
561 /// Determine if the function does not access memory.
562 bool doesNotAccessMemory() const;
563 void setDoesNotAccessMemory();
564
565 /// Determine if the function does not access or only reads memory.
566 bool onlyReadsMemory() const;
567 void setOnlyReadsMemory();
568
569 /// Determine if the function does not access or only writes memory.
570 bool onlyWritesMemory() const;
571 void setOnlyWritesMemory();
572
573 /// Determine if the call can access memory only using pointers based
574 /// on its arguments.
575 bool onlyAccessesArgMemory() const;
576 void setOnlyAccessesArgMemory();
577
578 /// Determine if the function may only access memory that is
579 /// inaccessible from the IR.
580 bool onlyAccessesInaccessibleMemory() const;
581 void setOnlyAccessesInaccessibleMemory();
582
583 /// Determine if the function may only access memory that is
584 /// either inaccessible from the IR or pointed to by its arguments.
585 bool onlyAccessesInaccessibleMemOrArgMem() const;
586 void setOnlyAccessesInaccessibleMemOrArgMem();
587
588 /// Determine if the function cannot return.
589 bool doesNotReturn() const {
590 return hasFnAttribute(Kind: Attribute::NoReturn);
591 }
592 void setDoesNotReturn() {
593 addFnAttr(Kind: Attribute::NoReturn);
594 }
595
596 /// Determine if the function should not perform indirect branch tracking.
597 bool doesNoCfCheck() const { return hasFnAttribute(Kind: Attribute::NoCfCheck); }
598
599 /// Determine if the function cannot unwind.
600 bool doesNotThrow() const {
601 return hasFnAttribute(Kind: Attribute::NoUnwind);
602 }
603 void setDoesNotThrow() {
604 addFnAttr(Kind: Attribute::NoUnwind);
605 }
606
607 /// Determine if the call cannot be duplicated.
608 bool cannotDuplicate() const {
609 return hasFnAttribute(Kind: Attribute::NoDuplicate);
610 }
611 void setCannotDuplicate() {
612 addFnAttr(Kind: Attribute::NoDuplicate);
613 }
614
615 /// Determine if the call is convergent.
616 bool isConvergent() const {
617 return hasFnAttribute(Kind: Attribute::Convergent);
618 }
619 void setConvergent() {
620 addFnAttr(Kind: Attribute::Convergent);
621 }
622 void setNotConvergent() {
623 removeFnAttr(Kind: Attribute::Convergent);
624 }
625
626 /// Determine if the call has sideeffects.
627 bool isSpeculatable() const {
628 return hasFnAttribute(Kind: Attribute::Speculatable);
629 }
630 void setSpeculatable() {
631 addFnAttr(Kind: Attribute::Speculatable);
632 }
633
634 /// Determine if the call might deallocate memory.
635 bool doesNotFreeMemory() const {
636 return onlyReadsMemory() || hasFnAttribute(Kind: Attribute::NoFree);
637 }
638 void setDoesNotFreeMemory() {
639 addFnAttr(Kind: Attribute::NoFree);
640 }
641
642 /// Determine if the call can synchroize with other threads
643 bool hasNoSync() const {
644 return hasFnAttribute(Kind: Attribute::NoSync);
645 }
646 void setNoSync() {
647 addFnAttr(Kind: Attribute::NoSync);
648 }
649
650 /// Determine if the function is known not to recurse, directly or
651 /// indirectly.
652 bool doesNotRecurse() const {
653 return hasFnAttribute(Kind: Attribute::NoRecurse);
654 }
655 void setDoesNotRecurse() {
656 addFnAttr(Kind: Attribute::NoRecurse);
657 }
658
659 /// Determine if the function is required to make forward progress.
660 bool mustProgress() const {
661 return hasFnAttribute(Kind: Attribute::MustProgress) ||
662 hasFnAttribute(Kind: Attribute::WillReturn);
663 }
664 void setMustProgress() { addFnAttr(Kind: Attribute::MustProgress); }
665
666 /// Determine if the function will return.
667 bool willReturn() const { return hasFnAttribute(Kind: Attribute::WillReturn); }
668 void setWillReturn() { addFnAttr(Kind: Attribute::WillReturn); }
669
670 /// Get what kind of unwind table entry to generate for this function.
671 UWTableKind getUWTableKind() const {
672 return AttributeSets.getUWTableKind();
673 }
674
675 /// True if the ABI mandates (or the user requested) that this
676 /// function be in a unwind table.
677 bool hasUWTable() const {
678 return getUWTableKind() != UWTableKind::None;
679 }
680 void setUWTableKind(UWTableKind K) {
681 if (K == UWTableKind::None)
682 removeFnAttr(Kind: Attribute::UWTable);
683 else
684 addFnAttr(Attr: Attribute::getWithUWTableKind(Context&: getContext(), Kind: K));
685 }
686 /// True if this function needs an unwind table.
687 bool needsUnwindTableEntry() const {
688 return hasUWTable() || !doesNotThrow() || hasPersonalityFn();
689 }
690
691 /// Determine if the function returns a structure through first
692 /// or second pointer argument.
693 bool hasStructRetAttr() const {
694 return AttributeSets.hasParamAttr(ArgNo: 0, Kind: Attribute::StructRet) ||
695 AttributeSets.hasParamAttr(ArgNo: 1, Kind: Attribute::StructRet);
696 }
697
698 /// Determine if the parameter or return value is marked with NoAlias
699 /// attribute.
700 bool returnDoesNotAlias() const {
701 return AttributeSets.hasRetAttr(Kind: Attribute::NoAlias);
702 }
703 void setReturnDoesNotAlias() { addRetAttr(Kind: Attribute::NoAlias); }
704
705 /// Do not optimize this function (-O0).
706 bool hasOptNone() const { return hasFnAttribute(Kind: Attribute::OptimizeNone); }
707
708 /// Optimize this function for minimum size (-Oz).
709 bool hasMinSize() const { return hasFnAttribute(Kind: Attribute::MinSize); }
710
711 /// Optimize this function for size (-Os) or minimum size (-Oz).
712 bool hasOptSize() const {
713 return hasFnAttribute(Kind: Attribute::OptimizeForSize) || hasMinSize();
714 }
715
716 /// Returns the denormal handling type for the default rounding mode of the
717 /// function.
718 DenormalMode getDenormalMode(const fltSemantics &FPType) const;
719
720 /// Return the representational value of "denormal-fp-math". Code interested
721 /// in the semantics of the function should use getDenormalMode instead.
722 DenormalMode getDenormalModeRaw() const;
723
724 /// Return the representational value of "denormal-fp-math-f32". Code
725 /// interested in the semantics of the function should use getDenormalMode
726 /// instead.
727 DenormalMode getDenormalModeF32Raw() const;
728
729 /// copyAttributesFrom - copy all additional attributes (those not needed to
730 /// create a Function) from the Function Src to this one.
731 void copyAttributesFrom(const Function *Src);
732
733 /// deleteBody - This method deletes the body of the function, and converts
734 /// the linkage to external.
735 ///
736 void deleteBody() {
737 deleteBodyImpl(/*ShouldDrop=*/ShouldDrop: false);
738 setLinkage(ExternalLinkage);
739 }
740
741 /// removeFromParent - This method unlinks 'this' from the containing module,
742 /// but does not delete it.
743 ///
744 void removeFromParent();
745
746 /// eraseFromParent - This method unlinks 'this' from the containing module
747 /// and deletes it.
748 ///
749 void eraseFromParent();
750
751 /// Steal arguments from another function.
752 ///
753 /// Drop this function's arguments and splice in the ones from \c Src.
754 /// Requires that this has no function body.
755 void stealArgumentListFrom(Function &Src);
756
757 /// Insert \p BB in the basic block list at \p Position. \Returns an iterator
758 /// to the newly inserted BB.
759 Function::iterator insert(Function::iterator Position, BasicBlock *BB) {
760 Function::iterator FIt = BasicBlocks.insert(where: Position, New: BB);
761 return FIt;
762 }
763
764 /// Transfer all blocks from \p FromF to this function at \p ToIt.
765 void splice(Function::iterator ToIt, Function *FromF) {
766 splice(ToIt, FromF, FromBeginIt: FromF->begin(), FromEndIt: FromF->end());
767 }
768
769 /// Transfer one BasicBlock from \p FromF at \p FromIt to this function
770 /// at \p ToIt.
771 void splice(Function::iterator ToIt, Function *FromF,
772 Function::iterator FromIt) {
773 auto FromItNext = std::next(x: FromIt);
774 // Single-element splice is a noop if destination == source.
775 if (ToIt == FromIt || ToIt == FromItNext)
776 return;
777 splice(ToIt, FromF, FromBeginIt: FromIt, FromEndIt: FromItNext);
778 }
779
780 /// Transfer a range of basic blocks that belong to \p FromF from \p
781 /// FromBeginIt to \p FromEndIt, to this function at \p ToIt.
782 void splice(Function::iterator ToIt, Function *FromF,
783 Function::iterator FromBeginIt,
784 Function::iterator FromEndIt);
785
786 /// Erases a range of BasicBlocks from \p FromIt to (not including) \p ToIt.
787 /// \Returns \p ToIt.
788 Function::iterator erase(Function::iterator FromIt, Function::iterator ToIt);
789
790private:
791 // These need access to the underlying BB list.
792 LLVM_ABI friend void BasicBlock::removeFromParent();
793 LLVM_ABI friend iplist<BasicBlock>::iterator BasicBlock::eraseFromParent();
794 template <class BB_t, class BB_i_t, class BI_t, class II_t>
795 friend class InstIterator;
796 friend class llvm::SymbolTableListTraits<llvm::BasicBlock>;
797 friend class llvm::ilist_node_with_parent<llvm::BasicBlock, llvm::Function>;
798
799 /// Get the underlying elements of the Function... the basic block list is
800 /// empty for external functions.
801 ///
802 /// This is deliberately private because we have implemented an adequate set
803 /// of functions to modify the list, including Function::splice(),
804 /// Function::erase(), Function::insert() etc.
805 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
806 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
807
808 static BasicBlockListType Function::*getSublistAccess(BasicBlock*) {
809 return &Function::BasicBlocks;
810 }
811
812public:
813 const BasicBlock &getEntryBlock() const { return front(); }
814 BasicBlock &getEntryBlock() { return front(); }
815
816 //===--------------------------------------------------------------------===//
817 // Symbol Table Accessing functions...
818
819 /// getSymbolTable() - Return the symbol table if any, otherwise nullptr.
820 ///
821 inline ValueSymbolTable *getValueSymbolTable() { return SymTab.get(); }
822 inline const ValueSymbolTable *getValueSymbolTable() const {
823 return SymTab.get();
824 }
825
826 //===--------------------------------------------------------------------===//
827 // Block number functions
828
829 /// Return a value larger than the largest block number. Intended to allocate
830 /// a vector that is sufficiently large to hold all blocks indexed by their
831 /// number.
832 unsigned getMaxBlockNumber() const { return NextBlockNum; }
833
834 /// Renumber basic blocks into a dense value range starting from 0. Be aware
835 /// that other data structures and analyses (e.g., DominatorTree) may depend
836 /// on the value numbers and need to be updated or invalidated.
837 void renumberBlocks();
838
839 /// Return the "epoch" of current block numbers. This will return a different
840 /// value after every renumbering. The intention is: if something (e.g., an
841 /// analysis) uses block numbers, it also stores the number epoch and then
842 /// can assert later on that the epoch didn't change (indicating that the
843 /// numbering is still valid). If the epoch changed, blocks might have been
844 /// assigned new numbers and previous uses of the numbers needs to be
845 /// invalidated. This is solely intended as a debugging feature.
846 unsigned getBlockNumberEpoch() const { return BlockNumEpoch; }
847
848private:
849 /// Assert that all blocks have unique numbers within 0..NextBlockNum. This
850 /// has O(n) runtime complexity.
851 void validateBlockNumbers() const;
852
853public:
854 //===--------------------------------------------------------------------===//
855 // BasicBlock iterator forwarding functions
856 //
857 iterator begin() { return BasicBlocks.begin(); }
858 const_iterator begin() const { return BasicBlocks.begin(); }
859 iterator end () { return BasicBlocks.end(); }
860 const_iterator end () const { return BasicBlocks.end(); }
861
862 size_t size() const { return BasicBlocks.size(); }
863 bool empty() const { return BasicBlocks.empty(); }
864 const BasicBlock &front() const { return BasicBlocks.front(); }
865 BasicBlock &front() { return BasicBlocks.front(); }
866 const BasicBlock &back() const { return BasicBlocks.back(); }
867 BasicBlock &back() { return BasicBlocks.back(); }
868
869/// @name Function Argument Iteration
870/// @{
871
872 arg_iterator arg_begin() {
873 CheckLazyArguments();
874 return Arguments;
875 }
876 const_arg_iterator arg_begin() const {
877 CheckLazyArguments();
878 return Arguments;
879 }
880
881 arg_iterator arg_end() {
882 CheckLazyArguments();
883 return Arguments + NumArgs;
884 }
885 const_arg_iterator arg_end() const {
886 CheckLazyArguments();
887 return Arguments + NumArgs;
888 }
889
890 Argument* getArg(unsigned i) const {
891 assert (i < NumArgs && "getArg() out of range!");
892 CheckLazyArguments();
893 return Arguments + i;
894 }
895
896 iterator_range<arg_iterator> args() {
897 return make_range(x: arg_begin(), y: arg_end());
898 }
899 iterator_range<const_arg_iterator> args() const {
900 return make_range(x: arg_begin(), y: arg_end());
901 }
902
903/// @}
904
905 size_t arg_size() const { return NumArgs; }
906 bool arg_empty() const { return arg_size() == 0; }
907
908 /// Check whether this function has a personality function.
909 bool hasPersonalityFn() const {
910 return getSubclassDataFromValue() & (1<<3);
911 }
912
913 /// Get the personality function associated with this function.
914 Constant *getPersonalityFn() const;
915 void setPersonalityFn(Constant *Fn);
916
917 /// Check whether this function has prefix data.
918 bool hasPrefixData() const {
919 return getSubclassDataFromValue() & (1<<1);
920 }
921
922 /// Get the prefix data associated with this function.
923 Constant *getPrefixData() const;
924 void setPrefixData(Constant *PrefixData);
925
926 /// Check whether this function has prologue data.
927 bool hasPrologueData() const {
928 return getSubclassDataFromValue() & (1<<2);
929 }
930
931 /// Get the prologue data associated with this function.
932 Constant *getPrologueData() const;
933 void setPrologueData(Constant *PrologueData);
934
935 /// Print the function to an output stream with an optional
936 /// AssemblyAnnotationWriter.
937 void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW = nullptr,
938 bool ShouldPreserveUseListOrder = false,
939 bool IsForDebug = false) const;
940
941 /// viewCFG - This function is meant for use from the debugger. You can just
942 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
943 /// program, displaying the CFG of the current function with the code for each
944 /// basic block inside. This depends on there being a 'dot' and 'gv' program
945 /// in your path.
946 ///
947 void viewCFG() const;
948
949 /// viewCFG - This function is meant for use from the debugger. It works just
950 /// like viewCFG(), but generates the dot file with the given file name.
951 void viewCFG(const char *OutputFileName) const;
952
953 /// Extended form to print edge weights.
954 void viewCFG(bool ViewCFGOnly, const BlockFrequencyInfo *BFI,
955 const BranchProbabilityInfo *BPI,
956 const char *OutputFileName = nullptr) const;
957
958 /// viewCFGOnly - This function is meant for use from the debugger. It works
959 /// just like viewCFG, but it does not include the contents of basic blocks
960 /// into the nodes, just the label. If you are only interested in the CFG
961 /// this can make the graph smaller.
962 ///
963 void viewCFGOnly() const;
964
965 /// viewCFG - This function is meant for use from the debugger. It works just
966 /// like viewCFGOnly(), but generates the dot file with the given file name.
967 void viewCFGOnly(const char *OutputFileName) const;
968
969 /// Extended form to print edge weights.
970 void viewCFGOnly(const BlockFrequencyInfo *BFI,
971 const BranchProbabilityInfo *BPI) const;
972
973 /// Methods for support type inquiry through isa, cast, and dyn_cast:
974 static bool classof(const Value *V) {
975 return V->getValueID() == Value::FunctionVal;
976 }
977
978 /// dropAllReferences() - This method causes all the subinstructions to "let
979 /// go" of all references that they are maintaining. This allows one to
980 /// 'delete' a whole module at a time, even though there may be circular
981 /// references... first all references are dropped, and all use counts go to
982 /// zero. Then everything is deleted for real. Note that no operations are
983 /// valid on an object that has "dropped all references", except operator
984 /// delete.
985 ///
986 /// Since no other object in the module can have references into the body of a
987 /// function, dropping all references deletes the entire body of the function,
988 /// including any contained basic blocks.
989 ///
990 void dropAllReferences() {
991 deleteBodyImpl(/*ShouldDrop=*/ShouldDrop: true);
992 }
993
994 /// hasAddressTaken - returns true if there are any uses of this function
995 /// other than direct calls or invokes to it, or blockaddress expressions.
996 /// Optionally passes back an offending user for diagnostic purposes,
997 /// ignores callback uses, assume like pointer annotation calls, references in
998 /// llvm.used and llvm.compiler.used variables, operand bundle
999 /// "clang.arc.attachedcall", and direct calls with a different call site
1000 /// signature (the function is implicitly casted).
1001 bool hasAddressTaken(const User ** = nullptr, bool IgnoreCallbackUses = false,
1002 bool IgnoreAssumeLikeCalls = true,
1003 bool IngoreLLVMUsed = false,
1004 bool IgnoreARCAttachedCall = false,
1005 bool IgnoreCastedDirectCall = false) const;
1006
1007 /// isDefTriviallyDead - Return true if it is trivially safe to remove
1008 /// this function definition from the module (because it isn't externally
1009 /// visible, does not have its address taken, and has no callers). To make
1010 /// this more accurate, call removeDeadConstantUsers first.
1011 bool isDefTriviallyDead() const;
1012
1013 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
1014 /// setjmp or other function that gcc recognizes as "returning twice".
1015 bool callsFunctionThatReturnsTwice() const;
1016
1017 /// Set the attached subprogram.
1018 ///
1019 /// Calls \a setMetadata() with \a LLVMContext::MD_dbg.
1020 void setSubprogram(DISubprogram *SP);
1021
1022 /// Get the attached subprogram.
1023 ///
1024 /// Calls \a getMetadata() with \a LLVMContext::MD_dbg and casts the result
1025 /// to \a DISubprogram.
1026 DISubprogram *getSubprogram() const;
1027
1028 /// Returns true if we should emit debug info for profiling.
1029 bool shouldEmitDebugInfoForProfiling() const;
1030
1031 /// Check if null pointer dereferencing is considered undefined behavior for
1032 /// the function.
1033 /// Return value: false => null pointer dereference is undefined.
1034 /// Return value: true => null pointer dereference is not undefined.
1035 bool nullPointerIsDefined() const;
1036
1037 /// Returns the alignment of the given function.
1038 ///
1039 /// Note that this is the alignment of the code, not the alignment of a
1040 /// function pointer.
1041 MaybeAlign getAlign() const { return GlobalObject::getAlign(); }
1042
1043 /// Sets the alignment attribute of the Function.
1044 void setAlignment(Align Align) { GlobalObject::setAlignment(Align); }
1045
1046 /// Sets the alignment attribute of the Function.
1047 ///
1048 /// This method will be deprecated as the alignment property should always be
1049 /// defined.
1050 void setAlignment(MaybeAlign Align) { GlobalObject::setAlignment(Align); }
1051
1052 /// Return the value for vscale based on the vscale_range attribute or 0 when
1053 /// unknown.
1054 unsigned getVScaleValue() const;
1055
1056private:
1057 void allocHungoffUselist();
1058 template<int Idx> void setHungoffOperand(Constant *C);
1059
1060 /// Shadow Value::setValueSubclassData with a private forwarding method so
1061 /// that subclasses cannot accidentally use it.
1062 void setValueSubclassData(unsigned short D) {
1063 Value::setValueSubclassData(D);
1064 }
1065 void setValueSubclassDataBit(unsigned Bit, bool On);
1066};
1067
1068namespace CallingConv {
1069
1070// TODO: Need similar function for support of argument in position. General
1071// version on FunctionType + Attributes + CallingConv::ID?
1072LLVM_ABI LLVM_READNONE bool supportsNonVoidReturnType(CallingConv::ID CC);
1073} // namespace CallingConv
1074
1075/// Check whether null pointer dereferencing is considered undefined behavior
1076/// for a given function or an address space.
1077/// Null pointer access in non-zero address space is not considered undefined.
1078/// Return value: false => null pointer dereference is undefined.
1079/// Return value: true => null pointer dereference is not undefined.
1080LLVM_ABI bool NullPointerIsDefined(const Function *F, unsigned AS = 0);
1081
1082template <> struct OperandTraits<Function> : public HungoffOperandTraits {};
1083
1084DEFINE_TRANSPARENT_OPERAND_ACCESSORS(Function, Value)
1085
1086} // end namespace llvm
1087
1088#endif // LLVM_IR_FUNCTION_H
1089