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 DenormalFPEnv;
53struct DenormalMode;
54class DISubprogram;
55enum LibFunc : unsigned;
56class LLVMContext;
57class Module;
58class raw_ostream;
59class TargetLibraryInfoImpl;
60class Type;
61class User;
62class BranchProbabilityInfo;
63class BlockFrequencyInfo;
64
65class LLVM_ABI Function : public GlobalObject, public ilist_node<Function> {
66public:
67 using BasicBlockListType = SymbolTableList<BasicBlock>;
68
69 // BasicBlock iterators...
70 using iterator = BasicBlockListType::iterator;
71 using const_iterator = BasicBlockListType::const_iterator;
72
73 using arg_iterator = Argument *;
74 using const_arg_iterator = const Argument *;
75
76private:
77 constexpr static HungOffOperandsAllocMarker AllocMarker{};
78
79 // Important things that make up a function!
80 BasicBlockListType BasicBlocks; ///< The basic blocks
81
82 // Basic blocks need to get their number when added to a function.
83 friend void BasicBlock::setParent(Function *);
84 unsigned NextBlockNum = 0;
85 /// Epoch of block numbers. (Could be shrinked to uint8_t if required.)
86 unsigned BlockNumEpoch = 0;
87
88 mutable Argument *Arguments = nullptr; ///< The formal arguments
89 uint32_t NumArgs;
90 MaybeAlign PreferredAlign;
91 std::unique_ptr<ValueSymbolTable>
92 SymTab; ///< Symbol table of args/instructions
93 AttributeList AttributeSets; ///< Parameter attributes
94
95 /*
96 * Value::SubclassData
97 *
98 * bit 0 : HasLazyArguments
99 * bit 1 : HasPrefixData
100 * bit 2 : HasPrologueData
101 * bit 3 : HasPersonalityFn
102 * bits 4-13 : CallingConvention
103 * bits 14 : HasGC
104 * bits 15 : [reserved]
105 */
106
107 /// Bits from GlobalObject::GlobalObjectSubclassData.
108 enum {
109 /// Whether this function is materializable.
110 IsMaterializableBit = 0,
111 };
112
113 friend class SymbolTableListTraits<Function>;
114
115public:
116 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
117 /// built on demand, so that the list isn't allocated until the first client
118 /// needs it. The hasLazyArguments predicate returns true if the arg list
119 /// hasn't been set up yet.
120 bool hasLazyArguments() const {
121 return getSubclassDataFromValue() & (1<<0);
122 }
123
124 /// \see BasicBlock::convertToNewDbgValues.
125 void convertToNewDbgValues();
126
127 /// \see BasicBlock::convertFromNewDbgValues.
128 void convertFromNewDbgValues();
129
130private:
131 friend class TargetLibraryInfoImpl;
132
133 static constexpr LibFunc UnknownLibFunc = LibFunc(-1);
134
135 /// Cache for TLI::getLibFunc() result without prototype validation.
136 /// UnknownLibFunc if uninitialized. NotLibFunc if definitely not lib func.
137 /// Otherwise may be libfunc if prototype validation passes.
138 mutable LibFunc LibFuncCache = UnknownLibFunc;
139
140 void CheckLazyArguments() const {
141 if (hasLazyArguments())
142 BuildLazyArguments();
143 }
144
145 void BuildLazyArguments() const;
146
147 void clearArguments();
148
149 void deleteBodyImpl(bool ShouldDrop);
150
151 /// Function ctor - If the (optional) Module argument is specified, the
152 /// function is automatically inserted into the end of the function list for
153 /// the module.
154 ///
155 Function(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace,
156 const Twine &N = "", Module *M = nullptr);
157
158public:
159 Function(const Function&) = delete;
160 void operator=(const Function&) = delete;
161 ~Function();
162
163 // This is here to help easily convert from FunctionT * (Function * or
164 // MachineFunction *) in BlockFrequencyInfoImpl to Function * by calling
165 // FunctionT->getFunction().
166 const Function &getFunction() const { return *this; }
167
168 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
169 unsigned AddrSpace, const Twine &N = "",
170 Module *M = nullptr) {
171 return new (AllocMarker) Function(Ty, Linkage, AddrSpace, N, M);
172 }
173
174 // TODO: remove this once all users have been updated to pass an AddrSpace
175 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
176 const Twine &N = "", Module *M = nullptr) {
177 return new (AllocMarker)
178 Function(Ty, Linkage, static_cast<unsigned>(-1), N, M);
179 }
180
181 /// Creates a new function and attaches it to a module.
182 ///
183 /// Places the function in the program address space as specified
184 /// by the module's data layout.
185 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
186 const Twine &N, Module &M);
187
188 /// Creates a function with some attributes recorded in llvm.module.flags
189 /// and the LLVMContext applied.
190 ///
191 /// Use this when synthesizing new functions that need attributes that would
192 /// have been set by command line options.
193 ///
194 /// This function should not be called from backends or the LTO pipeline. If
195 /// it is called from one of those places, some default attributes will not be
196 /// applied to the function.
197 static Function *createWithDefaultAttr(FunctionType *Ty, LinkageTypes Linkage,
198 unsigned AddrSpace,
199 const Twine &N = "",
200 Module *M = nullptr);
201
202 // Provide fast operand accessors.
203 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
204
205 /// Returns the number of non-debug IR instructions in this function.
206 /// This is equivalent to the sum of the sizes of each basic block contained
207 /// within this function.
208 unsigned getInstructionCount() const;
209
210 /// Returns the FunctionType for me.
211 FunctionType *getFunctionType() const {
212 return cast<FunctionType>(Val: getValueType());
213 }
214
215 /// Returns the type of the ret val.
216 Type *getReturnType() const { return getFunctionType()->getReturnType(); }
217
218 /// getContext - Return a reference to the LLVMContext associated with this
219 /// function.
220 LLVMContext &getContext() const;
221
222 /// Get the data layout of the module this function belongs to.
223 ///
224 /// Requires the function to have a parent module.
225 const DataLayout &getDataLayout() const;
226
227 /// isVarArg - Return true if this function takes a variable number of
228 /// arguments.
229 bool isVarArg() const { return getFunctionType()->isVarArg(); }
230
231 bool isMaterializable() const {
232 return getGlobalObjectSubClassData() & (1 << IsMaterializableBit);
233 }
234 void setIsMaterializable(bool V) {
235 unsigned Mask = 1 << IsMaterializableBit;
236 setGlobalObjectSubClassData((~Mask & getGlobalObjectSubClassData()) |
237 (V ? Mask : 0u));
238 }
239
240 /// getIntrinsicID - This method returns the ID number of the specified
241 /// function, or Intrinsic::not_intrinsic if the function is not an
242 /// intrinsic, or if the pointer is null. This value is always defined to be
243 /// zero to allow easy checking for whether a function is intrinsic or not.
244 /// The particular intrinsic functions which correspond to this value are
245 /// defined in llvm/Intrinsics.h.
246 Intrinsic::ID getIntrinsicID() const LLVM_READONLY { return IntID; }
247
248 /// isIntrinsic - Returns true if the function's name starts with "llvm.".
249 /// It's possible for this function to return true while getIntrinsicID()
250 /// returns Intrinsic::not_intrinsic!
251 bool isIntrinsic() const { return HasLLVMReservedName; }
252
253 /// isTargetIntrinsic - Returns true if this function is an intrinsic and the
254 /// intrinsic is specific to a certain target. If this is not an intrinsic
255 /// or a generic intrinsic, false is returned.
256 bool isTargetIntrinsic() const;
257
258 /// Returns true if the function is one of the "Constrained Floating-Point
259 /// Intrinsics". Returns false if not, and returns false when
260 /// getIntrinsicID() returns Intrinsic::not_intrinsic.
261 bool isConstrainedFPIntrinsic() const;
262
263 /// Update internal caches that depend on the function name (such as the
264 /// intrinsic ID and libcall cache).
265 /// Note, this method does not need to be called directly, as it is called
266 /// from Value::setName() whenever the name of this function changes.
267 void updateAfterNameChange();
268
269 /// getCallingConv()/setCallingConv(CC) - These method get and set the
270 /// calling convention of this function. The enum values for the known
271 /// calling conventions are defined in CallingConv.h.
272 CallingConv::ID getCallingConv() const {
273 return static_cast<CallingConv::ID>((getSubclassDataFromValue() >> 4) &
274 CallingConv::MaxID);
275 }
276 void setCallingConv(CallingConv::ID CC) {
277 auto ID = static_cast<unsigned>(CC);
278 assert(!(ID & ~CallingConv::MaxID) && "Unsupported calling convention");
279 setValueSubclassData((getSubclassDataFromValue() & 0xc00f) | (ID << 4));
280 }
281
282 /// Does it have a kernel calling convention?
283 bool hasKernelCallingConv() const {
284 switch (getCallingConv()) {
285 default:
286 return false;
287 case CallingConv::PTX_Kernel:
288 case CallingConv::AMDGPU_KERNEL:
289 case CallingConv::SPIR_KERNEL:
290 return true;
291 }
292 }
293
294 enum ProfileCountType { PCT_Real, PCT_Synthetic };
295
296 /// Class to represent profile counts.
297 ///
298 /// This class represents both real and synthetic profile counts.
299 class ProfileCount {
300 private:
301 uint64_t Count = 0;
302 ProfileCountType PCT = PCT_Real;
303
304 public:
305 ProfileCount(uint64_t Count, ProfileCountType PCT)
306 : Count(Count), PCT(PCT) {}
307 uint64_t getCount() const { return Count; }
308 ProfileCountType getType() const { return PCT; }
309 bool isSynthetic() const { return PCT == PCT_Synthetic; }
310 };
311
312 /// Set the entry count for this function.
313 ///
314 /// Entry count is the number of times this function was executed based on
315 /// pgo data. \p Imports points to a set of GUIDs that needs to
316 /// be imported by the function for sample PGO, to enable the same inlines as
317 /// the profiled optimized binary.
318 void setEntryCount(ProfileCount Count,
319 const DenseSet<GlobalValue::GUID> *Imports = nullptr);
320
321 /// A convenience wrapper for setting entry count
322 void setEntryCount(uint64_t Count, ProfileCountType Type = PCT_Real,
323 const DenseSet<GlobalValue::GUID> *Imports = nullptr);
324
325 /// Get the entry count for this function.
326 ///
327 /// Entry count is the number of times the function was executed.
328 /// When AllowSynthetic is false, only pgo_data will be returned.
329 std::optional<ProfileCount> getEntryCount(bool AllowSynthetic = false) const;
330
331 /// Return true if the function is annotated with profile data.
332 ///
333 /// Presence of entry counts from a profile run implies the function has
334 /// profile annotations. If IncludeSynthetic is false, only return true
335 /// when the profile data is real.
336 bool hasProfileData(bool IncludeSynthetic = false) const {
337 return getEntryCount(AllowSynthetic: IncludeSynthetic).has_value();
338 }
339
340 /// Returns the set of GUIDs that needs to be imported to the function for
341 /// sample PGO, to enable the same inlines as the profiled optimized binary.
342 DenseSet<GlobalValue::GUID> getImportGUIDs() const;
343
344 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
345 /// to use during code generation.
346 bool hasGC() const {
347 return getSubclassDataFromValue() & (1<<14);
348 }
349 const std::string &getGC() const;
350 void setGC(std::string Str);
351 void clearGC();
352
353 /// Return the attribute list for this Function.
354 AttributeList getAttributes() const { return AttributeSets; }
355
356 /// Set the attribute list for this Function.
357 void setAttributes(AttributeList Attrs) { AttributeSets = Attrs; }
358
359 // TODO: remove non-AtIndex versions of these methods.
360 /// adds the attribute to the list of attributes.
361 void addAttributeAtIndex(unsigned i, Attribute Attr);
362
363 /// Add function attributes to this function.
364 void addFnAttr(Attribute::AttrKind Kind);
365
366 /// Add function attributes to this function.
367 void addFnAttr(StringRef Kind, StringRef Val = StringRef());
368
369 /// Add function attributes to this function.
370 void addFnAttr(Attribute Attr);
371
372 /// Add function attributes to this function.
373 void addFnAttrs(const AttrBuilder &Attrs);
374
375 /// Add return value attributes to this function.
376 void addRetAttr(Attribute::AttrKind Kind);
377
378 /// Add return value attributes to this function.
379 void addRetAttr(Attribute Attr);
380
381 /// Add return value attributes to this function.
382 void addRetAttrs(const AttrBuilder &Attrs);
383
384 /// adds the attribute to the list of attributes for the given arg.
385 void addParamAttr(unsigned ArgNo, Attribute::AttrKind Kind);
386
387 /// adds the attribute to the list of attributes for the given arg.
388 void addParamAttr(unsigned ArgNo, Attribute Attr);
389
390 /// adds the attributes to the list of attributes for the given arg.
391 void addParamAttrs(unsigned ArgNo, const AttrBuilder &Attrs);
392
393 /// removes the attribute from the list of attributes.
394 void removeAttributeAtIndex(unsigned i, Attribute::AttrKind Kind);
395
396 /// removes the attribute from the list of attributes.
397 void removeAttributeAtIndex(unsigned i, StringRef Kind);
398
399 /// Remove function attributes from this function.
400 void removeFnAttr(Attribute::AttrKind Kind);
401
402 /// Remove function attribute from this function.
403 void removeFnAttr(StringRef Kind);
404
405 void removeFnAttrs(const AttributeMask &Attrs);
406
407 /// removes the attribute from the return value list of attributes.
408 void removeRetAttr(Attribute::AttrKind Kind);
409
410 /// removes the attribute from the return value list of attributes.
411 void removeRetAttr(StringRef Kind);
412
413 /// removes the attributes from the return value list of attributes.
414 void removeRetAttrs(const AttributeMask &Attrs);
415
416 /// removes the attribute from the list of attributes.
417 void removeParamAttr(unsigned ArgNo, Attribute::AttrKind Kind);
418
419 /// removes the attribute from the list of attributes.
420 void removeParamAttr(unsigned ArgNo, StringRef Kind);
421
422 /// removes the attribute from the list of attributes.
423 void removeParamAttrs(unsigned ArgNo, const AttributeMask &Attrs);
424
425 /// Return true if the function has the attribute.
426 bool hasFnAttribute(Attribute::AttrKind Kind) const;
427
428 /// Return true if the function has the attribute.
429 bool hasFnAttribute(StringRef Kind) const;
430
431 /// check if an attribute is in the list of attributes for the return value.
432 bool hasRetAttribute(Attribute::AttrKind Kind) const;
433
434 /// check if an attributes is in the list of attributes.
435 bool hasParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const;
436
437 /// Check if an attribute is in the list of attributes.
438 bool hasParamAttribute(unsigned ArgNo, StringRef Kind) const;
439
440 /// gets the attribute from the list of attributes.
441 Attribute getAttributeAtIndex(unsigned i, Attribute::AttrKind Kind) const;
442
443 /// gets the attribute from the list of attributes.
444 Attribute getAttributeAtIndex(unsigned i, StringRef Kind) const;
445
446 /// Check if attribute of the given kind is set at the given index.
447 bool hasAttributeAtIndex(unsigned Idx, Attribute::AttrKind Kind) const;
448
449 /// Return the attribute for the given attribute kind.
450 Attribute getFnAttribute(Attribute::AttrKind Kind) const;
451
452 /// Return the attribute for the given attribute kind.
453 Attribute getFnAttribute(StringRef Kind) const;
454
455 /// Return the attribute for the given attribute kind for the return value.
456 Attribute getRetAttribute(Attribute::AttrKind Kind) const;
457
458 /// For a string attribute \p Kind, parse attribute as an integer.
459 ///
460 /// \returns \p Default if attribute is not present.
461 ///
462 /// \returns \p Default if there is an error parsing the attribute integer,
463 /// and error is emitted to the LLVMContext
464 uint64_t getFnAttributeAsParsedInteger(StringRef Kind,
465 uint64_t Default = 0) const;
466
467 /// gets the specified attribute from the list of attributes.
468 Attribute getParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const;
469
470 /// Return the stack alignment for the function.
471 MaybeAlign getFnStackAlign() const {
472 return AttributeSets.getFnStackAlignment();
473 }
474
475 /// Returns true if the function has ssp, sspstrong, or sspreq fn attrs.
476 bool hasStackProtectorFnAttr() const;
477
478 /// adds the dereferenceable attribute to the list of attributes for
479 /// the given arg.
480 void addDereferenceableParamAttr(unsigned ArgNo, uint64_t Bytes);
481
482 /// adds the dereferenceable_or_null attribute to the list of
483 /// attributes for the given arg.
484 void addDereferenceableOrNullParamAttr(unsigned ArgNo, uint64_t Bytes);
485
486 /// adds the range attribute to the list of attributes for the return value.
487 void addRangeRetAttr(const ConstantRange &CR);
488
489 MaybeAlign getParamAlign(unsigned ArgNo) const {
490 return AttributeSets.getParamAlignment(ArgNo);
491 }
492
493 MaybeAlign getParamStackAlign(unsigned ArgNo) const {
494 return AttributeSets.getParamStackAlignment(ArgNo);
495 }
496
497 /// Extract the byval type for a parameter.
498 Type *getParamByValType(unsigned ArgNo) const {
499 return AttributeSets.getParamByValType(ArgNo);
500 }
501
502 /// Extract the sret type for a parameter.
503 Type *getParamStructRetType(unsigned ArgNo) const {
504 return AttributeSets.getParamStructRetType(ArgNo);
505 }
506
507 /// Extract the inalloca type for a parameter.
508 Type *getParamInAllocaType(unsigned ArgNo) const {
509 return AttributeSets.getParamInAllocaType(ArgNo);
510 }
511
512 /// Extract the byref type for a parameter.
513 Type *getParamByRefType(unsigned ArgNo) const {
514 return AttributeSets.getParamByRefType(ArgNo);
515 }
516
517 /// Extract the preallocated type for a parameter.
518 Type *getParamPreallocatedType(unsigned ArgNo) const {
519 return AttributeSets.getParamPreallocatedType(ArgNo);
520 }
521
522 /// Extract the number of dereferenceable bytes for a parameter.
523 /// @param ArgNo Index of an argument, with 0 being the first function arg.
524 uint64_t getParamDereferenceableBytes(unsigned ArgNo) const {
525 return AttributeSets.getParamDereferenceableBytes(Index: ArgNo);
526 }
527
528 /// Extract the number of dead_on_return bytes for a parameter.
529 /// @param ArgNo Index of an argument, with 0 being the first function arg.
530 DeadOnReturnInfo getDeadOnReturnInfo(unsigned ArgNo) const {
531 return AttributeSets.getDeadOnReturnInfo(Index: ArgNo);
532 }
533
534 /// Extract the number of dereferenceable_or_null bytes for a
535 /// parameter.
536 /// @param ArgNo AttributeList ArgNo, referring to an argument.
537 uint64_t getParamDereferenceableOrNullBytes(unsigned ArgNo) const {
538 return AttributeSets.getParamDereferenceableOrNullBytes(ArgNo);
539 }
540
541 /// Extract the nofpclass attribute for a parameter.
542 FPClassTest getParamNoFPClass(unsigned ArgNo) const {
543 return AttributeSets.getParamNoFPClass(ArgNo);
544 }
545
546 /// Determine if the function is presplit coroutine.
547 bool isPresplitCoroutine() const {
548 return hasFnAttribute(Kind: Attribute::PresplitCoroutine);
549 }
550 void setPresplitCoroutine() { addFnAttr(Kind: Attribute::PresplitCoroutine); }
551 void setSplittedCoroutine() { removeFnAttr(Kind: Attribute::PresplitCoroutine); }
552
553 bool isCoroOnlyDestroyWhenComplete() const {
554 return hasFnAttribute(Kind: Attribute::CoroDestroyOnlyWhenComplete);
555 }
556 void setCoroDestroyOnlyWhenComplete() {
557 addFnAttr(Kind: Attribute::CoroDestroyOnlyWhenComplete);
558 }
559
560 MemoryEffects getMemoryEffects() const;
561 void setMemoryEffects(MemoryEffects ME);
562
563 /// Determine if the function does not access memory.
564 bool doesNotAccessMemory() const;
565 void setDoesNotAccessMemory();
566
567 /// Determine if the function does not access or only reads memory.
568 bool onlyReadsMemory() const;
569 void setOnlyReadsMemory();
570
571 /// Determine if the function does not access or only writes memory.
572 bool onlyWritesMemory() const;
573 void setOnlyWritesMemory();
574
575 /// Determine if the call can access memory only using pointers based
576 /// on its arguments.
577 bool onlyAccessesArgMemory() const;
578 void setOnlyAccessesArgMemory();
579
580 /// Determine if the function may only access memory that is
581 /// inaccessible from the IR.
582 bool onlyAccessesInaccessibleMemory() const;
583 void setOnlyAccessesInaccessibleMemory();
584
585 /// Determine if the function may only access memory that is
586 /// either inaccessible from the IR or pointed to by its arguments.
587 bool onlyAccessesInaccessibleMemOrArgMem() const;
588 void setOnlyAccessesInaccessibleMemOrArgMem();
589
590 /// Determine if the function cannot return.
591 bool doesNotReturn() const {
592 return hasFnAttribute(Kind: Attribute::NoReturn);
593 }
594 void setDoesNotReturn() {
595 addFnAttr(Kind: Attribute::NoReturn);
596 }
597
598 /// Determine if the function should not perform indirect branch tracking.
599 bool doesNoCfCheck() const { return hasFnAttribute(Kind: Attribute::NoCfCheck); }
600
601 /// Determine if the function cannot unwind.
602 bool doesNotThrow() const {
603 return hasFnAttribute(Kind: Attribute::NoUnwind);
604 }
605 void setDoesNotThrow() {
606 addFnAttr(Kind: Attribute::NoUnwind);
607 }
608
609 /// Determine if the call cannot be duplicated.
610 bool cannotDuplicate() const {
611 return hasFnAttribute(Kind: Attribute::NoDuplicate);
612 }
613 void setCannotDuplicate() {
614 addFnAttr(Kind: Attribute::NoDuplicate);
615 }
616
617 /// Determine if the call is convergent.
618 bool isConvergent() const {
619 return hasFnAttribute(Kind: Attribute::Convergent);
620 }
621 void setConvergent() {
622 addFnAttr(Kind: Attribute::Convergent);
623 }
624 void setNotConvergent() {
625 removeFnAttr(Kind: Attribute::Convergent);
626 }
627
628 /// Determine if the call has sideeffects.
629 bool isSpeculatable() const {
630 return hasFnAttribute(Kind: Attribute::Speculatable);
631 }
632 void setSpeculatable() {
633 addFnAttr(Kind: Attribute::Speculatable);
634 }
635
636 /// Determine if the call might deallocate memory.
637 bool doesNotFreeMemory() const {
638 return onlyReadsMemory() || hasFnAttribute(Kind: Attribute::NoFree);
639 }
640 void setDoesNotFreeMemory() {
641 addFnAttr(Kind: Attribute::NoFree);
642 }
643
644 /// Determine if the call can synchroize with other threads
645 bool hasNoSync() const {
646 return hasFnAttribute(Kind: Attribute::NoSync);
647 }
648 void setNoSync() {
649 addFnAttr(Kind: Attribute::NoSync);
650 }
651
652 /// Determine if the function is known not to recurse, directly or
653 /// indirectly.
654 bool doesNotRecurse() const {
655 return hasFnAttribute(Kind: Attribute::NoRecurse);
656 }
657 void setDoesNotRecurse() {
658 addFnAttr(Kind: Attribute::NoRecurse);
659 }
660
661 /// Determine if the function is required to make forward progress.
662 bool mustProgress() const {
663 return hasFnAttribute(Kind: Attribute::MustProgress) ||
664 hasFnAttribute(Kind: Attribute::WillReturn);
665 }
666 void setMustProgress() { addFnAttr(Kind: Attribute::MustProgress); }
667
668 /// Determine if the function will return.
669 bool willReturn() const { return hasFnAttribute(Kind: Attribute::WillReturn); }
670 void setWillReturn() { addFnAttr(Kind: Attribute::WillReturn); }
671
672 /// Get what kind of unwind table entry to generate for this function.
673 UWTableKind getUWTableKind() const {
674 return AttributeSets.getUWTableKind();
675 }
676
677 /// True if the ABI mandates (or the user requested) that this
678 /// function be in a unwind table.
679 bool hasUWTable() const {
680 return getUWTableKind() != UWTableKind::None;
681 }
682 void setUWTableKind(UWTableKind K) {
683 if (K == UWTableKind::None)
684 removeFnAttr(Kind: Attribute::UWTable);
685 else
686 addFnAttr(Attr: Attribute::getWithUWTableKind(Context&: getContext(), Kind: K));
687 }
688 /// True if this function needs an unwind table.
689 bool needsUnwindTableEntry() const {
690 return hasUWTable() || !doesNotThrow() || hasPersonalityFn();
691 }
692
693 /// Determine if the function returns a structure through first
694 /// or second pointer argument.
695 bool hasStructRetAttr() const {
696 return AttributeSets.hasParamAttr(ArgNo: 0, Kind: Attribute::StructRet) ||
697 AttributeSets.hasParamAttr(ArgNo: 1, Kind: Attribute::StructRet);
698 }
699
700 /// Determine if the parameter or return value is marked with NoAlias
701 /// attribute.
702 bool returnDoesNotAlias() const {
703 return AttributeSets.hasRetAttr(Kind: Attribute::NoAlias);
704 }
705 void setReturnDoesNotAlias() { addRetAttr(Kind: Attribute::NoAlias); }
706
707 /// Do not optimize this function (-O0).
708 bool hasOptNone() const { return hasFnAttribute(Kind: Attribute::OptimizeNone); }
709
710 /// Optimize this function for minimum size (-Oz).
711 bool hasMinSize() const { return hasFnAttribute(Kind: Attribute::MinSize); }
712
713 /// Optimize this function for size (-Os) or minimum size (-Oz).
714 bool hasOptSize() const {
715 return hasFnAttribute(Kind: Attribute::OptimizeForSize) || hasMinSize();
716 }
717
718 /// Returns the denormal handling type for the default rounding mode of the
719 /// function.
720 DenormalMode getDenormalMode(const fltSemantics &FPType) const;
721
722 /// Return the representational value of the denormal_fpenv attribute.
723 DenormalFPEnv getDenormalFPEnv() const;
724
725 /// copyAttributesFrom - copy all additional attributes (those not needed to
726 /// create a Function) from the Function Src to this one.
727 void copyAttributesFrom(const Function *Src);
728
729 /// deleteBody - This method deletes the body of the function, and converts
730 /// the linkage to external.
731 ///
732 void deleteBody() {
733 deleteBodyImpl(/*ShouldDrop=*/ShouldDrop: false);
734 setLinkage(ExternalLinkage);
735 }
736
737 /// removeFromParent - This method unlinks 'this' from the containing module,
738 /// but does not delete it.
739 ///
740 void removeFromParent();
741
742 /// eraseFromParent - This method unlinks 'this' from the containing module
743 /// and deletes it.
744 ///
745 void eraseFromParent();
746
747 /// Steal arguments from another function.
748 ///
749 /// Drop this function's arguments and splice in the ones from \c Src.
750 /// Requires that this has no function body.
751 void stealArgumentListFrom(Function &Src);
752
753 /// Insert \p BB in the basic block list at \p Position. \Returns an iterator
754 /// to the newly inserted BB.
755 Function::iterator insert(Function::iterator Position, BasicBlock *BB) {
756 Function::iterator FIt = BasicBlocks.insert(where: Position, New: BB);
757 return FIt;
758 }
759
760 /// Transfer all blocks from \p FromF to this function at \p ToIt.
761 void splice(Function::iterator ToIt, Function *FromF) {
762 splice(ToIt, FromF, FromBeginIt: FromF->begin(), FromEndIt: FromF->end());
763 }
764
765 /// Transfer one BasicBlock from \p FromF at \p FromIt to this function
766 /// at \p ToIt.
767 void splice(Function::iterator ToIt, Function *FromF,
768 Function::iterator FromIt) {
769 auto FromItNext = std::next(x: FromIt);
770 // Single-element splice is a noop if destination == source.
771 if (ToIt == FromIt || ToIt == FromItNext)
772 return;
773 splice(ToIt, FromF, FromBeginIt: FromIt, FromEndIt: FromItNext);
774 }
775
776 /// Transfer a range of basic blocks that belong to \p FromF from \p
777 /// FromBeginIt to \p FromEndIt, to this function at \p ToIt.
778 void splice(Function::iterator ToIt, Function *FromF,
779 Function::iterator FromBeginIt,
780 Function::iterator FromEndIt);
781
782 /// Erases a range of BasicBlocks from \p FromIt to (not including) \p ToIt.
783 /// \Returns \p ToIt.
784 Function::iterator erase(Function::iterator FromIt, Function::iterator ToIt);
785
786private:
787 // These need access to the underlying BB list.
788 LLVM_ABI friend void BasicBlock::removeFromParent();
789 LLVM_ABI friend iplist<BasicBlock>::iterator BasicBlock::eraseFromParent();
790 template <class BB_t, class BB_i_t, class BI_t, class II_t>
791 friend class InstIterator;
792 friend class llvm::SymbolTableListTraits<llvm::BasicBlock>;
793 friend class llvm::ilist_node_with_parent<llvm::BasicBlock, llvm::Function>;
794
795 /// Get the underlying elements of the Function... the basic block list is
796 /// empty for external functions.
797 ///
798 /// This is deliberately private because we have implemented an adequate set
799 /// of functions to modify the list, including Function::splice(),
800 /// Function::erase(), Function::insert() etc.
801 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
802 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
803
804 static BasicBlockListType Function::*getSublistAccess(BasicBlock*) {
805 return &Function::BasicBlocks;
806 }
807
808public:
809 const BasicBlock &getEntryBlock() const { return front(); }
810 BasicBlock &getEntryBlock() { return front(); }
811
812 //===--------------------------------------------------------------------===//
813 // Symbol Table Accessing functions...
814
815 /// getSymbolTable() - Return the symbol table if any, otherwise nullptr.
816 ///
817 inline ValueSymbolTable *getValueSymbolTable() { return SymTab.get(); }
818 inline const ValueSymbolTable *getValueSymbolTable() const {
819 return SymTab.get();
820 }
821
822 //===--------------------------------------------------------------------===//
823 // Block number functions
824
825 /// Return a value larger than the largest block number. Intended to allocate
826 /// a vector that is sufficiently large to hold all blocks indexed by their
827 /// number.
828 unsigned getMaxBlockNumber() const { return NextBlockNum; }
829
830 /// Renumber basic blocks into a dense value range starting from 0. Be aware
831 /// that other data structures and analyses (e.g., DominatorTree) may depend
832 /// on the value numbers and need to be updated or invalidated.
833 void renumberBlocks();
834
835 /// Return the "epoch" of current block numbers. This will return a different
836 /// value after every renumbering. The intention is: if something (e.g., an
837 /// analysis) uses block numbers, it also stores the number epoch and then
838 /// can assert later on that the epoch didn't change (indicating that the
839 /// numbering is still valid). If the epoch changed, blocks might have been
840 /// assigned new numbers and previous uses of the numbers needs to be
841 /// invalidated. This is solely intended as a debugging feature.
842 unsigned getBlockNumberEpoch() const { return BlockNumEpoch; }
843
844private:
845 /// Assert that all blocks have unique numbers within 0..NextBlockNum. This
846 /// has O(n) runtime complexity.
847 void validateBlockNumbers() const;
848
849public:
850 //===--------------------------------------------------------------------===//
851 // BasicBlock iterator forwarding functions
852 //
853 iterator begin() { return BasicBlocks.begin(); }
854 const_iterator begin() const { return BasicBlocks.begin(); }
855 iterator end () { return BasicBlocks.end(); }
856 const_iterator end () const { return BasicBlocks.end(); }
857
858 size_t size() const { return BasicBlocks.size(); }
859 bool empty() const { return BasicBlocks.empty(); }
860 const BasicBlock &front() const { return BasicBlocks.front(); }
861 BasicBlock &front() { return BasicBlocks.front(); }
862 const BasicBlock &back() const { return BasicBlocks.back(); }
863 BasicBlock &back() { return BasicBlocks.back(); }
864
865/// @name Function Argument Iteration
866/// @{
867
868 arg_iterator arg_begin() {
869 CheckLazyArguments();
870 return Arguments;
871 }
872 const_arg_iterator arg_begin() const {
873 CheckLazyArguments();
874 return Arguments;
875 }
876
877 arg_iterator arg_end() {
878 CheckLazyArguments();
879 return Arguments + NumArgs;
880 }
881 const_arg_iterator arg_end() const {
882 CheckLazyArguments();
883 return Arguments + NumArgs;
884 }
885
886 Argument* getArg(unsigned i) const {
887 assert (i < NumArgs && "getArg() out of range!");
888 CheckLazyArguments();
889 return Arguments + i;
890 }
891
892 iterator_range<arg_iterator> args() {
893 return make_range(x: arg_begin(), y: arg_end());
894 }
895 iterator_range<const_arg_iterator> args() const {
896 return make_range(x: arg_begin(), y: arg_end());
897 }
898
899/// @}
900
901 size_t arg_size() const { return NumArgs; }
902 bool arg_empty() const { return arg_size() == 0; }
903
904 /// Check whether this function has a personality function.
905 bool hasPersonalityFn() const {
906 return getSubclassDataFromValue() & (1<<3);
907 }
908
909 /// Get the personality function associated with this function.
910 Constant *getPersonalityFn() const;
911 void setPersonalityFn(Constant *Fn);
912
913 /// Check whether this function has prefix data.
914 bool hasPrefixData() const {
915 return getSubclassDataFromValue() & (1<<1);
916 }
917
918 /// Get the prefix data associated with this function.
919 Constant *getPrefixData() const;
920 void setPrefixData(Constant *PrefixData);
921
922 /// Check whether this function has prologue data.
923 bool hasPrologueData() const {
924 return getSubclassDataFromValue() & (1<<2);
925 }
926
927 /// Get the prologue data associated with this function.
928 Constant *getPrologueData() const;
929 void setPrologueData(Constant *PrologueData);
930
931 /// Print the function to an output stream with an optional
932 /// AssemblyAnnotationWriter.
933 void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW = nullptr,
934 bool ShouldPreserveUseListOrder = false,
935 bool IsForDebug = false) const;
936
937 /// viewCFG - This function is meant for use from the debugger. You can just
938 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
939 /// program, displaying the CFG of the current function with the code for each
940 /// basic block inside. This depends on there being a 'dot' and 'gv' program
941 /// in your path.
942 ///
943 void viewCFG() const;
944
945 /// viewCFG - This function is meant for use from the debugger. It works just
946 /// like viewCFG(), but generates the dot file with the given file name.
947 void viewCFG(const char *OutputFileName) const;
948
949 /// Extended form to print edge weights.
950 void viewCFG(bool ViewCFGOnly, const BlockFrequencyInfo *BFI,
951 const BranchProbabilityInfo *BPI,
952 const char *OutputFileName = nullptr) const;
953
954 /// viewCFGOnly - This function is meant for use from the debugger. It works
955 /// just like viewCFG, but it does not include the contents of basic blocks
956 /// into the nodes, just the label. If you are only interested in the CFG
957 /// this can make the graph smaller.
958 ///
959 void viewCFGOnly() const;
960
961 /// viewCFG - This function is meant for use from the debugger. It works just
962 /// like viewCFGOnly(), but generates the dot file with the given file name.
963 void viewCFGOnly(const char *OutputFileName) const;
964
965 /// Extended form to print edge weights.
966 void viewCFGOnly(const BlockFrequencyInfo *BFI,
967 const BranchProbabilityInfo *BPI) const;
968
969 /// Methods for support type inquiry through isa, cast, and dyn_cast:
970 static bool classof(const Value *V) {
971 return V->getValueID() == Value::FunctionVal;
972 }
973
974 /// dropAllReferences() - This method causes all the subinstructions to "let
975 /// go" of all references that they are maintaining. This allows one to
976 /// 'delete' a whole module at a time, even though there may be circular
977 /// references... first all references are dropped, and all use counts go to
978 /// zero. Then everything is deleted for real. Note that no operations are
979 /// valid on an object that has "dropped all references", except operator
980 /// delete.
981 ///
982 /// Since no other object in the module can have references into the body of a
983 /// function, dropping all references deletes the entire body of the function,
984 /// including any contained basic blocks.
985 ///
986 void dropAllReferences() {
987 deleteBodyImpl(/*ShouldDrop=*/ShouldDrop: true);
988 }
989
990 /// hasAddressTaken - returns true if there are any uses of this function
991 /// other than direct calls or invokes to it, or blockaddress expressions.
992 /// Optionally passes back an offending user for diagnostic purposes,
993 /// ignores callback uses, assume like pointer annotation calls, references in
994 /// llvm.used and llvm.compiler.used variables, operand bundle
995 /// "clang.arc.attachedcall", and direct calls with a different call site
996 /// signature (the function is implicitly casted).
997 bool hasAddressTaken(const User ** = nullptr, bool IgnoreCallbackUses = false,
998 bool IgnoreAssumeLikeCalls = true,
999 bool IngoreLLVMUsed = false,
1000 bool IgnoreARCAttachedCall = false,
1001 bool IgnoreCastedDirectCall = false) const;
1002
1003 /// isDefTriviallyDead - Return true if it is trivially safe to remove
1004 /// this function definition from the module (because it isn't externally
1005 /// visible, does not have its address taken, and has no callers). To make
1006 /// this more accurate, call removeDeadConstantUsers first.
1007 bool isDefTriviallyDead() const;
1008
1009 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
1010 /// setjmp or other function that gcc recognizes as "returning twice".
1011 bool callsFunctionThatReturnsTwice() const;
1012
1013 /// Set the attached subprogram.
1014 ///
1015 /// Calls \a setMetadata() with \a LLVMContext::MD_dbg.
1016 void setSubprogram(DISubprogram *SP);
1017
1018 /// Get the attached subprogram.
1019 ///
1020 /// Calls \a getMetadata() with \a LLVMContext::MD_dbg and casts the result
1021 /// to \a DISubprogram.
1022 DISubprogram *getSubprogram() const;
1023
1024 /// Returns true if we should emit debug info for profiling.
1025 bool shouldEmitDebugInfoForProfiling() const;
1026
1027 /// Check if null pointer dereferencing is considered undefined behavior for
1028 /// the function.
1029 /// Return value: false => null pointer dereference is undefined.
1030 /// Return value: true => null pointer dereference is not undefined.
1031 bool nullPointerIsDefined() const;
1032
1033 /// Returns the alignment of the given function.
1034 ///
1035 /// Note that this is the alignment of the code, not the alignment of a
1036 /// function pointer.
1037 MaybeAlign getAlign() const { return GlobalObject::getAlign(); }
1038
1039 /// Sets the alignment attribute of the Function.
1040 void setAlignment(Align Align) { GlobalObject::setAlignment(Align); }
1041
1042 /// Sets the alignment attribute of the Function.
1043 ///
1044 /// This method will be deprecated as the alignment property should always be
1045 /// defined.
1046 void setAlignment(MaybeAlign Align) { GlobalObject::setAlignment(Align); }
1047
1048 /// Returns the prefalign of the given function.
1049 MaybeAlign getPreferredAlignment() const { return PreferredAlign; }
1050
1051 /// Sets the prefalign attribute of the Function.
1052 void setPreferredAlignment(MaybeAlign Align) { PreferredAlign = Align; }
1053
1054 /// Return the value for vscale based on the vscale_range attribute or 0 when
1055 /// unknown.
1056 unsigned getVScaleValue() const;
1057
1058private:
1059 void allocHungoffUselist();
1060 template<int Idx> void setHungoffOperand(Constant *C);
1061
1062 /// Shadow Value::setValueSubclassData with a private forwarding method so
1063 /// that subclasses cannot accidentally use it.
1064 void setValueSubclassData(unsigned short D) {
1065 Value::setValueSubclassData(D);
1066 }
1067 void setValueSubclassDataBit(unsigned Bit, bool On);
1068};
1069
1070namespace CallingConv {
1071
1072// TODO: Need similar function for support of argument in position. General
1073// version on FunctionType + Attributes + CallingConv::ID?
1074LLVM_ABI LLVM_READNONE bool supportsNonVoidReturnType(CallingConv::ID CC);
1075} // namespace CallingConv
1076
1077/// Check whether null pointer dereferencing is considered undefined behavior
1078/// for a given function or an address space.
1079/// Null pointer access in non-zero address space is not considered undefined.
1080/// Return value: false => null pointer dereference is undefined.
1081/// Return value: true => null pointer dereference is not undefined.
1082LLVM_ABI bool NullPointerIsDefined(const Function *F, unsigned AS = 0);
1083
1084template <> struct OperandTraits<Function> : public HungoffOperandTraits {};
1085
1086DEFINE_TRANSPARENT_OPERAND_ACCESSORS(Function, Value)
1087
1088} // end namespace llvm
1089
1090#endif // LLVM_IR_FUNCTION_H
1091