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/Casting.h"
36#include "llvm/Support/Compiler.h"
37#include <cassert>
38#include <cstddef>
39#include <cstdint>
40#include <memory>
41#include <string>
42
43namespace llvm {
44
45namespace Intrinsic {
46typedef unsigned ID;
47}
48
49class AssemblyAnnotationWriter;
50class Constant;
51class DISubprogram;
52class LLVMContext;
53class Module;
54template <typename T> class Optional;
55class raw_ostream;
56class Type;
57class User;
58class BranchProbabilityInfo;
59class BlockFrequencyInfo;
60
61class Function : public GlobalObject, public ilist_node<Function> {
62public:
63 using BasicBlockListType = SymbolTableList<BasicBlock>;
64
65 // BasicBlock iterators...
66 using iterator = BasicBlockListType::iterator;
67 using const_iterator = BasicBlockListType::const_iterator;
68
69 using arg_iterator = Argument *;
70 using const_arg_iterator = const Argument *;
71
72private:
73 // Important things that make up a function!
74 BasicBlockListType BasicBlocks; ///< The basic blocks
75 mutable Argument *Arguments = nullptr; ///< The formal arguments
76 size_t NumArgs;
77 std::unique_ptr<ValueSymbolTable>
78 SymTab; ///< Symbol table of args/instructions
79 AttributeList AttributeSets; ///< Parameter attributes
80
81 /*
82 * Value::SubclassData
83 *
84 * bit 0 : HasLazyArguments
85 * bit 1 : HasPrefixData
86 * bit 2 : HasPrologueData
87 * bit 3 : HasPersonalityFn
88 * bits 4-13 : CallingConvention
89 * bits 14 : HasGC
90 * bits 15 : [reserved]
91 */
92
93 /// Bits from GlobalObject::GlobalObjectSubclassData.
94 enum {
95 /// Whether this function is materializable.
96 IsMaterializableBit = 0,
97 };
98
99 friend class SymbolTableListTraits<Function>;
100
101 /// hasLazyArguments/CheckLazyArguments - The argument list of a function is
102 /// built on demand, so that the list isn't allocated until the first client
103 /// needs it. The hasLazyArguments predicate returns true if the arg list
104 /// hasn't been set up yet.
105public:
106 bool hasLazyArguments() const {
107 return getSubclassDataFromValue() & (1<<0);
108 }
109
110private:
111 void CheckLazyArguments() const {
112 if (hasLazyArguments())
113 BuildLazyArguments();
114 }
115
116 void BuildLazyArguments() const;
117
118 void clearArguments();
119
120 /// Function ctor - If the (optional) Module argument is specified, the
121 /// function is automatically inserted into the end of the function list for
122 /// the module.
123 ///
124 Function(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace,
125 const Twine &N = "", Module *M = nullptr);
126
127public:
128 Function(const Function&) = delete;
129 void operator=(const Function&) = delete;
130 ~Function();
131
132 // This is here to help easily convert from FunctionT * (Function * or
133 // MachineFunction *) in BlockFrequencyInfoImpl to Function * by calling
134 // FunctionT->getFunction().
135 const Function &getFunction() const { return *this; }
136
137 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
138 unsigned AddrSpace, const Twine &N = "",
139 Module *M = nullptr) {
140 return new Function(Ty, Linkage, AddrSpace, N, M);
141 }
142
143 // TODO: remove this once all users have been updated to pass an AddrSpace
144 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
145 const Twine &N = "", Module *M = nullptr) {
146 return new Function(Ty, Linkage, static_cast<unsigned>(-1), N, M);
147 }
148
149 /// Creates a new function and attaches it to a module.
150 ///
151 /// Places the function in the program address space as specified
152 /// by the module's data layout.
153 static Function *Create(FunctionType *Ty, LinkageTypes Linkage,
154 const Twine &N, Module &M);
155
156 /// Creates a function with some attributes recorded in llvm.module.flags
157 /// applied.
158 ///
159 /// Use this when synthesizing new functions that need attributes that would
160 /// have been set by command line options.
161 static Function *createWithDefaultAttr(FunctionType *Ty, LinkageTypes Linkage,
162 unsigned AddrSpace,
163 const Twine &N = "",
164 Module *M = nullptr);
165
166 // Provide fast operand accessors.
167 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
168
169 /// Returns the number of non-debug IR instructions in this function.
170 /// This is equivalent to the sum of the sizes of each basic block contained
171 /// within this function.
172 unsigned getInstructionCount() const;
173
174 /// Returns the FunctionType for me.
175 FunctionType *getFunctionType() const {
176 return cast<FunctionType>(getValueType());
177 }
178
179 /// Returns the type of the ret val.
180 Type *getReturnType() const { return getFunctionType()->getReturnType(); }
181
182 /// getContext - Return a reference to the LLVMContext associated with this
183 /// function.
184 LLVMContext &getContext() const;
185
186 /// isVarArg - Return true if this function takes a variable number of
187 /// arguments.
188 bool isVarArg() const { return getFunctionType()->isVarArg(); }
189
190 bool isMaterializable() const {
191 return getGlobalObjectSubClassData() & (1 << IsMaterializableBit);
192 }
193 void setIsMaterializable(bool V) {
194 unsigned Mask = 1 << IsMaterializableBit;
195 setGlobalObjectSubClassData((~Mask & getGlobalObjectSubClassData()) |
196 (V ? Mask : 0u));
197 }
198
199 /// getIntrinsicID - This method returns the ID number of the specified
200 /// function, or Intrinsic::not_intrinsic if the function is not an
201 /// intrinsic, or if the pointer is null. This value is always defined to be
202 /// zero to allow easy checking for whether a function is intrinsic or not.
203 /// The particular intrinsic functions which correspond to this value are
204 /// defined in llvm/Intrinsics.h.
205 Intrinsic::ID getIntrinsicID() const LLVM_READONLY { return IntID; }
206
207 /// isIntrinsic - Returns true if the function's name starts with "llvm.".
208 /// It's possible for this function to return true while getIntrinsicID()
209 /// returns Intrinsic::not_intrinsic!
210 bool isIntrinsic() const { return HasLLVMReservedName; }
211
212 /// isTargetIntrinsic - Returns true if IID is an intrinsic specific to a
213 /// certain target. If it is a generic intrinsic false is returned.
214 static bool isTargetIntrinsic(Intrinsic::ID IID);
215
216 /// isTargetIntrinsic - Returns true if this function is an intrinsic and the
217 /// intrinsic is specific to a certain target. If this is not an intrinsic
218 /// or a generic intrinsic, false is returned.
219 bool isTargetIntrinsic() const;
220
221 /// Returns true if the function is one of the "Constrained Floating-Point
222 /// Intrinsics". Returns false if not, and returns false when
223 /// getIntrinsicID() returns Intrinsic::not_intrinsic.
224 bool isConstrainedFPIntrinsic() const;
225
226 static Intrinsic::ID lookupIntrinsicID(StringRef Name);
227
228 /// Recalculate the ID for this function if it is an Intrinsic defined
229 /// in llvm/Intrinsics.h. Sets the intrinsic ID to Intrinsic::not_intrinsic
230 /// if the name of this function does not match an intrinsic in that header.
231 /// Note, this method does not need to be called directly, as it is called
232 /// from Value::setName() whenever the name of this function changes.
233 void recalculateIntrinsicID();
234
235 /// getCallingConv()/setCallingConv(CC) - These method get and set the
236 /// calling convention of this function. The enum values for the known
237 /// calling conventions are defined in CallingConv.h.
238 CallingConv::ID getCallingConv() const {
239 return static_cast<CallingConv::ID>((getSubclassDataFromValue() >> 4) &
240 CallingConv::MaxID);
241 }
242 void setCallingConv(CallingConv::ID CC) {
243 auto ID = static_cast<unsigned>(CC);
244 assert(!(ID & ~CallingConv::MaxID) && "Unsupported calling convention");
245 setValueSubclassData((getSubclassDataFromValue() & 0xc00f) | (ID << 4));
246 }
247
248 /// Return the attribute list for this Function.
249 AttributeList getAttributes() const { return AttributeSets; }
250
251 /// Set the attribute list for this Function.
252 void setAttributes(AttributeList Attrs) { AttributeSets = Attrs; }
253
254 /// Add function attributes to this function.
255 void addFnAttr(Attribute::AttrKind Kind) {
256 addAttribute(AttributeList::FunctionIndex, Kind);
257 }
258
259 /// Add function attributes to this function.
260 void addFnAttr(StringRef Kind, StringRef Val = StringRef()) {
261 addAttribute(AttributeList::FunctionIndex,
262 Attribute::get(getContext(), Kind, Val));
263 }
264
265 /// Add function attributes to this function.
266 void addFnAttr(Attribute Attr) {
267 addAttribute(AttributeList::FunctionIndex, Attr);
268 }
269
270 /// Remove function attributes from this function.
271 void removeFnAttr(Attribute::AttrKind Kind) {
272 removeAttribute(AttributeList::FunctionIndex, Kind);
273 }
274
275 /// Remove function attribute from this function.
276 void removeFnAttr(StringRef Kind) {
277 setAttributes(getAttributes().removeAttribute(
278 getContext(), AttributeList::FunctionIndex, Kind));
279 }
280
281 /// A function will have the "coroutine.presplit" attribute if it's
282 /// a coroutine and has not gone through full CoroSplit pass.
283 bool isPresplitCoroutine() const {
284 return hasFnAttribute("coroutine.presplit");
285 }
286
287 enum ProfileCountType { PCT_Invalid, PCT_Real, PCT_Synthetic };
288
289 /// Class to represent profile counts.
290 ///
291 /// This class represents both real and synthetic profile counts.
292 class ProfileCount {
293 private:
294 uint64_t Count;
295 ProfileCountType PCT;
296 static ProfileCount Invalid;
297
298 public:
299 ProfileCount() : Count(-1), PCT(PCT_Invalid) {}
300 ProfileCount(uint64_t Count, ProfileCountType PCT)
301 : Count(Count), PCT(PCT) {}
302 bool hasValue() const { return PCT != PCT_Invalid; }
303 uint64_t getCount() const { return Count; }
304 ProfileCountType getType() const { return PCT; }
305 bool isSynthetic() const { return PCT == PCT_Synthetic; }
306 explicit operator bool() { return hasValue(); }
307 bool operator!() const { return !hasValue(); }
308 // Update the count retaining the same profile count type.
309 ProfileCount &setCount(uint64_t C) {
310 Count = C;
311 return *this;
312 }
313 static ProfileCount getInvalid() { return ProfileCount(-1, PCT_Invalid); }
314 };
315
316 /// Set the entry count for this function.
317 ///
318 /// Entry count is the number of times this function was executed based on
319 /// pgo data. \p Imports points to a set of GUIDs that needs to
320 /// be imported by the function for sample PGO, to enable the same inlines as
321 /// the profiled optimized binary.
322 void setEntryCount(ProfileCount Count,
323 const DenseSet<GlobalValue::GUID> *Imports = nullptr);
324
325 /// A convenience wrapper for setting entry count
326 void setEntryCount(uint64_t Count, ProfileCountType Type = PCT_Real,
327 const DenseSet<GlobalValue::GUID> *Imports = nullptr);
328
329 /// Get the entry count for this function.
330 ///
331 /// Entry count is the number of times the function was executed.
332 /// When AllowSynthetic is false, only pgo_data will be returned.
333 ProfileCount getEntryCount(bool AllowSynthetic = false) const;
334
335 /// Return true if the function is annotated with profile data.
336 ///
337 /// Presence of entry counts from a profile run implies the function has
338 /// profile annotations. If IncludeSynthetic is false, only return true
339 /// when the profile data is real.
340 bool hasProfileData(bool IncludeSynthetic = false) const {
341 return getEntryCount(IncludeSynthetic).hasValue();
342 }
343
344 /// Returns the set of GUIDs that needs to be imported to the function for
345 /// sample PGO, to enable the same inlines as the profiled optimized binary.
346 DenseSet<GlobalValue::GUID> getImportGUIDs() const;
347
348 /// Set the section prefix for this function.
349 void setSectionPrefix(StringRef Prefix);
350
351 /// Get the section prefix for this function.
352 Optional<StringRef> getSectionPrefix() const;
353
354 /// Return true if the function has the attribute.
355 bool hasFnAttribute(Attribute::AttrKind Kind) const {
356 return AttributeSets.hasFnAttribute(Kind);
357 }
358
359 /// Return true if the function has the attribute.
360 bool hasFnAttribute(StringRef Kind) const {
361 return AttributeSets.hasFnAttribute(Kind);
362 }
363
364 /// Return the attribute for the given attribute kind.
365 Attribute getFnAttribute(Attribute::AttrKind Kind) const {
366 return getAttribute(AttributeList::FunctionIndex, Kind);
367 }
368
369 /// Return the attribute for the given attribute kind.
370 Attribute getFnAttribute(StringRef Kind) const {
371 return getAttribute(AttributeList::FunctionIndex, Kind);
372 }
373
374 /// Return the stack alignment for the function.
375 unsigned getFnStackAlignment() const {
376 if (!hasFnAttribute(Attribute::StackAlignment))
377 return 0;
378 if (const auto MA =
379 AttributeSets.getStackAlignment(AttributeList::FunctionIndex))
380 return MA->value();
381 return 0;
382 }
383
384 /// Return the stack alignment for the function.
385 MaybeAlign getFnStackAlign() const {
386 if (!hasFnAttribute(Attribute::StackAlignment))
387 return None;
388 return AttributeSets.getStackAlignment(AttributeList::FunctionIndex);
389 }
390
391 /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
392 /// to use during code generation.
393 bool hasGC() const {
394 return getSubclassDataFromValue() & (1<<14);
395 }
396 const std::string &getGC() const;
397 void setGC(std::string Str);
398 void clearGC();
399
400 /// Returns true if the function has ssp, sspstrong, or sspreq fn attrs.
401 bool hasStackProtectorFnAttr() const;
402
403 /// adds the attribute to the list of attributes.
404 void addAttribute(unsigned i, Attribute::AttrKind Kind);
405
406 /// adds the attribute to the list of attributes.
407 void addAttribute(unsigned i, Attribute Attr);
408
409 /// adds the attributes to the list of attributes.
410 void addAttributes(unsigned i, const AttrBuilder &Attrs);
411
412 /// adds the attribute to the list of attributes for the given arg.
413 void addParamAttr(unsigned ArgNo, Attribute::AttrKind Kind);
414
415 /// adds the attribute to the list of attributes for the given arg.
416 void addParamAttr(unsigned ArgNo, Attribute Attr);
417
418 /// adds the attributes to the list of attributes for the given arg.
419 void addParamAttrs(unsigned ArgNo, const AttrBuilder &Attrs);
420
421 /// removes the attribute from the list of attributes.
422 void removeAttribute(unsigned i, Attribute::AttrKind Kind);
423
424 /// removes the attribute from the list of attributes.
425 void removeAttribute(unsigned i, StringRef Kind);
426
427 /// removes the attributes from the list of attributes.
428 void removeAttributes(unsigned i, const AttrBuilder &Attrs);
429
430 /// removes the attribute from the list of attributes.
431 void removeParamAttr(unsigned ArgNo, Attribute::AttrKind Kind);
432
433 /// removes the attribute from the list of attributes.
434 void removeParamAttr(unsigned ArgNo, StringRef Kind);
435
436 /// removes the attribute from the list of attributes.
437 void removeParamAttrs(unsigned ArgNo, const AttrBuilder &Attrs);
438
439 /// removes noundef and other attributes that imply undefined behavior if a
440 /// `undef` or `poison` value is passed from the list of attributes.
441 void removeParamUndefImplyingAttrs(unsigned ArgNo);
442
443 /// check if an attributes is in the list of attributes.
444 bool hasAttribute(unsigned i, Attribute::AttrKind Kind) const {
445 return getAttributes().hasAttribute(i, Kind);
446 }
447
448 /// check if an attributes is in the list of attributes.
449 bool hasParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const {
450 return getAttributes().hasParamAttribute(ArgNo, Kind);
451 }
452
453 /// gets the specified attribute from the list of attributes.
454 Attribute getParamAttribute(unsigned ArgNo, Attribute::AttrKind Kind) const {
455 return getAttributes().getParamAttr(ArgNo, Kind);
456 }
457
458 /// gets the attribute from the list of attributes.
459 Attribute getAttribute(unsigned i, Attribute::AttrKind Kind) const {
460 return AttributeSets.getAttribute(i, Kind);
461 }
462
463 /// gets the attribute from the list of attributes.
464 Attribute getAttribute(unsigned i, StringRef Kind) const {
465 return AttributeSets.getAttribute(i, Kind);
466 }
467
468 /// adds the dereferenceable attribute to the list of attributes.
469 void addDereferenceableAttr(unsigned i, uint64_t Bytes);
470
471 /// adds the dereferenceable attribute to the list of attributes for
472 /// the given arg.
473 void addDereferenceableParamAttr(unsigned ArgNo, uint64_t Bytes);
474
475 /// adds the dereferenceable_or_null attribute to the list of
476 /// attributes.
477 void addDereferenceableOrNullAttr(unsigned i, uint64_t Bytes);
478
479 /// adds the dereferenceable_or_null attribute to the list of
480 /// attributes for the given arg.
481 void addDereferenceableOrNullParamAttr(unsigned ArgNo, uint64_t Bytes);
482
483 /// Extract the alignment for a call or parameter (0=unknown).
484 /// FIXME: Remove this function once transition to Align is over.
485 /// Use getParamAlign() instead.
486 unsigned getParamAlignment(unsigned ArgNo) const {
487 if (const auto MA = getParamAlign(ArgNo))
488 return MA->value();
489 return 0;
490 }
491
492 MaybeAlign getParamAlign(unsigned ArgNo) const {
493 return AttributeSets.getParamAlignment(ArgNo);
494 }
495
496 MaybeAlign getParamStackAlign(unsigned ArgNo) const {
497 return AttributeSets.getParamStackAlignment(ArgNo);
498 }
499
500 /// Extract the byval type for a parameter.
501 Type *getParamByValType(unsigned ArgNo) const {
502 return AttributeSets.getParamByValType(ArgNo);
503 }
504
505 /// Extract the sret type for a parameter.
506 Type *getParamStructRetType(unsigned ArgNo) const {
507 return AttributeSets.getParamStructRetType(ArgNo);
508 }
509
510 /// Extract the inalloca type for a parameter.
511 Type *getParamInAllocaType(unsigned ArgNo) const {
512 return AttributeSets.getParamInAllocaType(ArgNo);
513 }
514
515 /// Extract the byref type for a parameter.
516 Type *getParamByRefType(unsigned ArgNo) const {
517 return AttributeSets.getParamByRefType(ArgNo);
518 }
519
520 /// Extract the number of dereferenceable bytes for a call or
521 /// parameter (0=unknown).
522 /// @param i AttributeList index, referring to a return value or argument.
523 uint64_t getDereferenceableBytes(unsigned i) const {
524 return AttributeSets.getDereferenceableBytes(i);
525 }
526
527 /// Extract the number of dereferenceable bytes for a parameter.
528 /// @param ArgNo Index of an argument, with 0 being the first function arg.
529 uint64_t getParamDereferenceableBytes(unsigned ArgNo) const {
530 return AttributeSets.getParamDereferenceableBytes(ArgNo);
531 }
532
533 /// Extract the number of dereferenceable_or_null bytes for a call or
534 /// parameter (0=unknown).
535 /// @param i AttributeList index, referring to a return value or argument.
536 uint64_t getDereferenceableOrNullBytes(unsigned i) const {
537 return AttributeSets.getDereferenceableOrNullBytes(i);
538 }
539
540 /// Extract the number of dereferenceable_or_null bytes for a
541 /// parameter.
542 /// @param ArgNo AttributeList ArgNo, referring to an argument.
543 uint64_t getParamDereferenceableOrNullBytes(unsigned ArgNo) const {
544 return AttributeSets.getParamDereferenceableOrNullBytes(ArgNo);
545 }
546
547 /// Determine if the function does not access memory.
548 bool doesNotAccessMemory() const {
549 return hasFnAttribute(Attribute::ReadNone);
550 }
551 void setDoesNotAccessMemory() {
552 addFnAttr(Attribute::ReadNone);
553 }
554
555 /// Determine if the function does not access or only reads memory.
556 bool onlyReadsMemory() const {
557 return doesNotAccessMemory() || hasFnAttribute(Attribute::ReadOnly);
558 }
559 void setOnlyReadsMemory() {
560 addFnAttr(Attribute::ReadOnly);
561 }
562
563 /// Determine if the function does not access or only writes memory.
564 bool doesNotReadMemory() const {
565 return doesNotAccessMemory() || hasFnAttribute(Attribute::WriteOnly);
566 }
567 void setDoesNotReadMemory() {
568 addFnAttr(Attribute::WriteOnly);
569 }
570
571 /// Determine if the call can access memmory only using pointers based
572 /// on its arguments.
573 bool onlyAccessesArgMemory() const {
574 return hasFnAttribute(Attribute::ArgMemOnly);
575 }
576 void setOnlyAccessesArgMemory() { addFnAttr(Attribute::ArgMemOnly); }
577
578 /// Determine if the function may only access memory that is
579 /// inaccessible from the IR.
580 bool onlyAccessesInaccessibleMemory() const {
581 return hasFnAttribute(Attribute::InaccessibleMemOnly);
582 }
583 void setOnlyAccessesInaccessibleMemory() {
584 addFnAttr(Attribute::InaccessibleMemOnly);
585 }
586
587 /// Determine if the function may only access memory that is
588 /// either inaccessible from the IR or pointed to by its arguments.
589 bool onlyAccessesInaccessibleMemOrArgMem() const {
590 return hasFnAttribute(Attribute::InaccessibleMemOrArgMemOnly);
591 }
592 void setOnlyAccessesInaccessibleMemOrArgMem() {
593 addFnAttr(Attribute::InaccessibleMemOrArgMemOnly);
594 }
595
596 /// Determine if the function cannot return.
597 bool doesNotReturn() const {
598 return hasFnAttribute(Attribute::NoReturn);
599 }
600 void setDoesNotReturn() {
601 addFnAttr(Attribute::NoReturn);
602 }
603
604 /// Determine if the function should not perform indirect branch tracking.
605 bool doesNoCfCheck() const { return hasFnAttribute(Attribute::NoCfCheck); }
606
607 /// Determine if the function cannot unwind.
608 bool doesNotThrow() const {
609 return hasFnAttribute(Attribute::NoUnwind);
610 }
611 void setDoesNotThrow() {
612 addFnAttr(Attribute::NoUnwind);
613 }
614
615 /// Determine if the call cannot be duplicated.
616 bool cannotDuplicate() const {
617 return hasFnAttribute(Attribute::NoDuplicate);
618 }
619 void setCannotDuplicate() {
620 addFnAttr(Attribute::NoDuplicate);
621 }
622
623 /// Determine if the call is convergent.
624 bool isConvergent() const {
625 return hasFnAttribute(Attribute::Convergent);
626 }
627 void setConvergent() {
628 addFnAttr(Attribute::Convergent);
629 }
630 void setNotConvergent() {
631 removeFnAttr(Attribute::Convergent);
632 }
633
634 /// Determine if the call has sideeffects.
635 bool isSpeculatable() const {
636 return hasFnAttribute(Attribute::Speculatable);
637 }
638 void setSpeculatable() {
639 addFnAttr(Attribute::Speculatable);
640 }
641
642 /// Determine if the call might deallocate memory.
643 bool doesNotFreeMemory() const {
644 return onlyReadsMemory() || hasFnAttribute(Attribute::NoFree);
645 }
646 void setDoesNotFreeMemory() {
647 addFnAttr(Attribute::NoFree);
648 }
649
650 /// Determine if the call can synchroize with other threads
651 bool hasNoSync() const {
652 return hasFnAttribute(Attribute::NoSync);
653 }
654 void setNoSync() {
655 addFnAttr(Attribute::NoSync);
656 }
657
658 /// Determine if the function is known not to recurse, directly or
659 /// indirectly.
660 bool doesNotRecurse() const {
661 return hasFnAttribute(Attribute::NoRecurse);
662 }
663 void setDoesNotRecurse() {
664 addFnAttr(Attribute::NoRecurse);
665 }
666
667 /// Determine if the function is required to make forward progress.
668 bool mustProgress() const {
669 return hasFnAttribute(Attribute::MustProgress) ||
670 hasFnAttribute(Attribute::WillReturn);
671 }
672 void setMustProgress() { addFnAttr(Attribute::MustProgress); }
673
674 /// Determine if the function will return.
675 bool willReturn() const { return hasFnAttribute(Attribute::WillReturn); }
676 void setWillReturn() { addFnAttr(Attribute::WillReturn); }
677
678 /// True if the ABI mandates (or the user requested) that this
679 /// function be in a unwind table.
680 bool hasUWTable() const {
681 return hasFnAttribute(Attribute::UWTable);
682 }
683 void setHasUWTable() {
684 addFnAttr(Attribute::UWTable);
685 }
686
687 /// True if this function needs an unwind table.
688 bool needsUnwindTableEntry() const {
689 return hasUWTable() || !doesNotThrow() || hasPersonalityFn();
690 }
691
692 /// Determine if the function returns a structure through first
693 /// or second pointer argument.
694 bool hasStructRetAttr() const {
695 return AttributeSets.hasParamAttribute(0, Attribute::StructRet) ||
696 AttributeSets.hasParamAttribute(1, Attribute::StructRet);
697 }
698
699 /// Determine if the parameter or return value is marked with NoAlias
700 /// attribute.
701 bool returnDoesNotAlias() const {
702 return AttributeSets.hasAttribute(AttributeList::ReturnIndex,
703 Attribute::NoAlias);
704 }
705 void setReturnDoesNotAlias() {
706 addAttribute(AttributeList::ReturnIndex, Attribute::NoAlias);
707 }
708
709 /// Do not optimize this function (-O0).
710 bool hasOptNone() const { return hasFnAttribute(Attribute::OptimizeNone); }
711
712 /// Optimize this function for minimum size (-Oz).
713 bool hasMinSize() const { return hasFnAttribute(Attribute::MinSize); }
714
715 /// Optimize this function for size (-Os) or minimum size (-Oz).
716 bool hasOptSize() const {
717 return hasFnAttribute(Attribute::OptimizeForSize) || hasMinSize();
718 }
719
720 /// Returns the denormal handling type for the default rounding mode of the
721 /// function.
722 DenormalMode getDenormalMode(const fltSemantics &FPType) const;
723
724 /// copyAttributesFrom - copy all additional attributes (those not needed to
725 /// create a Function) from the Function Src to this one.
726 void copyAttributesFrom(const Function *Src);
727
728 /// deleteBody - This method deletes the body of the function, and converts
729 /// the linkage to external.
730 ///
731 void deleteBody() {
732 dropAllReferences();
733 setLinkage(ExternalLinkage);
734 }
735
736 /// removeFromParent - This method unlinks 'this' from the containing module,
737 /// but does not delete it.
738 ///
739 void removeFromParent();
740
741 /// eraseFromParent - This method unlinks 'this' from the containing module
742 /// and deletes it.
743 ///
744 void eraseFromParent();
745
746 /// Steal arguments from another function.
747 ///
748 /// Drop this function's arguments and splice in the ones from \c Src.
749 /// Requires that this has no function body.
750 void stealArgumentListFrom(Function &Src);
751
752 /// Get the underlying elements of the Function... the basic block list is
753 /// empty for external functions.
754 ///
755 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; }
756 BasicBlockListType &getBasicBlockList() { return BasicBlocks; }
757
758 static BasicBlockListType Function::*getSublistAccess(BasicBlock*) {
759 return &Function::BasicBlocks;
760 }
761
762 const BasicBlock &getEntryBlock() const { return front(); }
763 BasicBlock &getEntryBlock() { return front(); }
764
765 //===--------------------------------------------------------------------===//
766 // Symbol Table Accessing functions...
767
768 /// getSymbolTable() - Return the symbol table if any, otherwise nullptr.
769 ///
770 inline ValueSymbolTable *getValueSymbolTable() { return SymTab.get(); }
771 inline const ValueSymbolTable *getValueSymbolTable() const {
772 return SymTab.get();
773 }
774
775 //===--------------------------------------------------------------------===//
776 // BasicBlock iterator forwarding functions
777 //
778 iterator begin() { return BasicBlocks.begin(); }
779 const_iterator begin() const { return BasicBlocks.begin(); }
780 iterator end () { return BasicBlocks.end(); }
781 const_iterator end () const { return BasicBlocks.end(); }
782
783 size_t size() const { return BasicBlocks.size(); }
784 bool empty() const { return BasicBlocks.empty(); }
785 const BasicBlock &front() const { return BasicBlocks.front(); }
786 BasicBlock &front() { return BasicBlocks.front(); }
787 const BasicBlock &back() const { return BasicBlocks.back(); }
788 BasicBlock &back() { return BasicBlocks.back(); }
789
790/// @name Function Argument Iteration
791/// @{
792
793 arg_iterator arg_begin() {
794 CheckLazyArguments();
795 return Arguments;
796 }
797 const_arg_iterator arg_begin() const {
798 CheckLazyArguments();
799 return Arguments;
800 }
801
802 arg_iterator arg_end() {
803 CheckLazyArguments();
804 return Arguments + NumArgs;
805 }
806 const_arg_iterator arg_end() const {
807 CheckLazyArguments();
808 return Arguments + NumArgs;
809 }
810
811 Argument* getArg(unsigned i) const {
812 assert (i < NumArgs && "getArg() out of range!");
813 CheckLazyArguments();
814 return Arguments + i;
815 }
816
817 iterator_range<arg_iterator> args() {
818 return make_range(arg_begin(), arg_end());
819 }
820 iterator_range<const_arg_iterator> args() const {
821 return make_range(arg_begin(), arg_end());
822 }
823
824/// @}
825
826 size_t arg_size() const { return NumArgs; }
827 bool arg_empty() const { return arg_size() == 0; }
828
829 /// Check whether this function has a personality function.
830 bool hasPersonalityFn() const {
831 return getSubclassDataFromValue() & (1<<3);
832 }
833
834 /// Get the personality function associated with this function.
835 Constant *getPersonalityFn() const;
836 void setPersonalityFn(Constant *Fn);
837
838 /// Check whether this function has prefix data.
839 bool hasPrefixData() const {
840 return getSubclassDataFromValue() & (1<<1);
841 }
842
843 /// Get the prefix data associated with this function.
844 Constant *getPrefixData() const;
845 void setPrefixData(Constant *PrefixData);
846
847 /// Check whether this function has prologue data.
848 bool hasPrologueData() const {
849 return getSubclassDataFromValue() & (1<<2);
850 }
851
852 /// Get the prologue data associated with this function.
853 Constant *getPrologueData() const;
854 void setPrologueData(Constant *PrologueData);
855
856 /// Print the function to an output stream with an optional
857 /// AssemblyAnnotationWriter.
858 void print(raw_ostream &OS, AssemblyAnnotationWriter *AAW = nullptr,
859 bool ShouldPreserveUseListOrder = false,
860 bool IsForDebug = false) const;
861
862 /// viewCFG - This function is meant for use from the debugger. You can just
863 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
864 /// program, displaying the CFG of the current function with the code for each
865 /// basic block inside. This depends on there being a 'dot' and 'gv' program
866 /// in your path.
867 ///
868 void viewCFG() const;
869
870 /// Extended form to print edge weights.
871 void viewCFG(bool ViewCFGOnly, const BlockFrequencyInfo *BFI,
872 const BranchProbabilityInfo *BPI) const;
873
874 /// viewCFGOnly - This function is meant for use from the debugger. It works
875 /// just like viewCFG, but it does not include the contents of basic blocks
876 /// into the nodes, just the label. If you are only interested in the CFG
877 /// this can make the graph smaller.
878 ///
879 void viewCFGOnly() const;
880
881 /// Extended form to print edge weights.
882 void viewCFGOnly(const BlockFrequencyInfo *BFI,
883 const BranchProbabilityInfo *BPI) const;
884
885 /// Methods for support type inquiry through isa, cast, and dyn_cast:
886 static bool classof(const Value *V) {
887 return V->getValueID() == Value::FunctionVal;
888 }
889
890 /// dropAllReferences() - This method causes all the subinstructions to "let
891 /// go" of all references that they are maintaining. This allows one to
892 /// 'delete' a whole module at a time, even though there may be circular
893 /// references... first all references are dropped, and all use counts go to
894 /// zero. Then everything is deleted for real. Note that no operations are
895 /// valid on an object that has "dropped all references", except operator
896 /// delete.
897 ///
898 /// Since no other object in the module can have references into the body of a
899 /// function, dropping all references deletes the entire body of the function,
900 /// including any contained basic blocks.
901 ///
902 void dropAllReferences();
903
904 /// hasAddressTaken - returns true if there are any uses of this function
905 /// other than direct calls or invokes to it, or blockaddress expressions.
906 /// Optionally passes back an offending user for diagnostic purposes,
907 /// ignores callback uses, assume like pointer annotation calls, and
908 /// references in llvm.used and llvm.compiler.used variables.
909 ///
910 bool hasAddressTaken(const User ** = nullptr,
911 bool IgnoreCallbackUses = false,
912 bool IgnoreAssumeLikeCalls = true,
913 bool IngoreLLVMUsed = false) const;
914
915 /// isDefTriviallyDead - Return true if it is trivially safe to remove
916 /// this function definition from the module (because it isn't externally
917 /// visible, does not have its address taken, and has no callers). To make
918 /// this more accurate, call removeDeadConstantUsers first.
919 bool isDefTriviallyDead() const;
920
921 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
922 /// setjmp or other function that gcc recognizes as "returning twice".
923 bool callsFunctionThatReturnsTwice() const;
924
925 /// Set the attached subprogram.
926 ///
927 /// Calls \a setMetadata() with \a LLVMContext::MD_dbg.
928 void setSubprogram(DISubprogram *SP);
929
930 /// Get the attached subprogram.
931 ///
932 /// Calls \a getMetadata() with \a LLVMContext::MD_dbg and casts the result
933 /// to \a DISubprogram.
934 DISubprogram *getSubprogram() const;
935
936 /// Returns true if we should emit debug info for profiling.
937 bool isDebugInfoForProfiling() const;
938
939 /// Check if null pointer dereferencing is considered undefined behavior for
940 /// the function.
941 /// Return value: false => null pointer dereference is undefined.
942 /// Return value: true => null pointer dereference is not undefined.
943 bool nullPointerIsDefined() const;
944
945private:
946 void allocHungoffUselist();
947 template<int Idx> void setHungoffOperand(Constant *C);
948
949 /// Shadow Value::setValueSubclassData with a private forwarding method so
950 /// that subclasses cannot accidentally use it.
951 void setValueSubclassData(unsigned short D) {
952 Value::setValueSubclassData(D);
953 }
954 void setValueSubclassDataBit(unsigned Bit, bool On);
955};
956
957/// Check whether null pointer dereferencing is considered undefined behavior
958/// for a given function or an address space.
959/// Null pointer access in non-zero address space is not considered undefined.
960/// Return value: false => null pointer dereference is undefined.
961/// Return value: true => null pointer dereference is not undefined.
962bool NullPointerIsDefined(const Function *F, unsigned AS = 0);
963
964template <>
965struct OperandTraits<Function> : public HungoffOperandTraits<3> {};
966
967DEFINE_TRANSPARENT_OPERAND_ACCESSORS(Function, Value)
968
969} // end namespace llvm
970
971#endif // LLVM_IR_FUNCTION_H
972