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