1 //===- CallSite.h - Abstract Call & Invoke instrs ---------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the CallSite class, which is a handy wrapper for code that
11 // wants to treat Call and Invoke instructions in a generic way. When in non-
12 // mutation context (e.g. an analysis) ImmutableCallSite should be used.
13 // Finally, when some degree of customization is necessary between these two
14 // extremes, CallSiteBase<> can be supplied with fine-tuned parameters.
15 //
16 // NOTE: These classes are supposed to have "value semantics". So they should be
17 // passed by value, not by reference; they should not be "new"ed or "delete"d.
18 // They are efficiently copyable, assignable and constructable, with cost
19 // equivalent to copying a pointer (notice that they have only a single data
20 // member). The internal representation carries a flag which indicates which of
21 // the two variants is enclosed. This allows for cheaper checks when various
22 // accessors of CallSite are employed.
23 //
24 //===----------------------------------------------------------------------===//
25 
26 #ifndef LLVM_IR_CALLSITE_H
27 #define LLVM_IR_CALLSITE_H
28 
29 #include "llvm/ADT/PointerIntPair.h"
30 #include "llvm/ADT/iterator_range.h"
31 #include "llvm/IR/Attributes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Instructions.h"
34 
35 namespace llvm {
36 
37 class CallInst;
38 class InvokeInst;
39 
40 template <typename FunTy = const Function,
41           typename BBTy = const BasicBlock,
42           typename ValTy = const Value,
43           typename UserTy = const User,
44           typename UseTy = const Use,
45           typename InstrTy = const Instruction,
46           typename CallTy = const CallInst,
47           typename InvokeTy = const InvokeInst,
48           typename IterTy = User::const_op_iterator>
49 class CallSiteBase {
50 protected:
51   PointerIntPair<InstrTy*, 1, bool> I;
52 
CallSiteBase()53   CallSiteBase() : I(nullptr, false) {}
CallSiteBase(CallTy * CI)54   CallSiteBase(CallTy *CI) : I(CI, true) { assert(CI); }
CallSiteBase(InvokeTy * II)55   CallSiteBase(InvokeTy *II) : I(II, false) { assert(II); }
CallSiteBase(ValTy * II)56   explicit CallSiteBase(ValTy *II) { *this = get(II); }
57 
58 private:
59   /// CallSiteBase::get - This static method is sort of like a constructor.  It
60   /// will create an appropriate call site for a Call or Invoke instruction, but
61   /// it can also create a null initialized CallSiteBase object for something
62   /// which is NOT a call site.
63   ///
get(ValTy * V)64   static CallSiteBase get(ValTy *V) {
65     if (InstrTy *II = dyn_cast<InstrTy>(V)) {
66       if (II->getOpcode() == Instruction::Call)
67         return CallSiteBase(static_cast<CallTy*>(II));
68       else if (II->getOpcode() == Instruction::Invoke)
69         return CallSiteBase(static_cast<InvokeTy*>(II));
70     }
71     return CallSiteBase();
72   }
73 
74 public:
75   /// isCall - true if a CallInst is enclosed.
76   /// Note that !isCall() does not mean it is an InvokeInst enclosed,
77   /// it also could signify a NULL Instruction pointer.
isCall()78   bool isCall() const { return I.getInt(); }
79 
80   /// isInvoke - true if a InvokeInst is enclosed.
81   ///
isInvoke()82   bool isInvoke() const { return getInstruction() && !I.getInt(); }
83 
getInstruction()84   InstrTy *getInstruction() const { return I.getPointer(); }
85   InstrTy *operator->() const { return I.getPointer(); }
86   explicit operator bool() const { return I.getPointer(); }
87 
88   /// Get the basic block containing the call site
getParent()89   BBTy* getParent() const { return getInstruction()->getParent(); }
90 
91   /// getCalledValue - Return the pointer to function that is being called.
92   ///
getCalledValue()93   ValTy *getCalledValue() const {
94     assert(getInstruction() && "Not a call or invoke instruction!");
95     return *getCallee();
96   }
97 
98   /// getCalledFunction - Return the function being called if this is a direct
99   /// call, otherwise return null (if it's an indirect call).
100   ///
getCalledFunction()101   FunTy *getCalledFunction() const {
102     return dyn_cast<FunTy>(getCalledValue());
103   }
104 
105   /// setCalledFunction - Set the callee to the specified value.
106   ///
setCalledFunction(Value * V)107   void setCalledFunction(Value *V) {
108     assert(getInstruction() && "Not a call or invoke instruction!");
109     *getCallee() = V;
110   }
111 
112   /// isCallee - Determine whether the passed iterator points to the
113   /// callee operand's Use.
isCallee(Value::const_user_iterator UI)114   bool isCallee(Value::const_user_iterator UI) const {
115     return isCallee(&UI.getUse());
116   }
117 
118   /// Determine whether this Use is the callee operand's Use.
isCallee(const Use * U)119   bool isCallee(const Use *U) const { return getCallee() == U; }
120 
getArgument(unsigned ArgNo)121   ValTy *getArgument(unsigned ArgNo) const {
122     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
123     return *(arg_begin() + ArgNo);
124   }
125 
setArgument(unsigned ArgNo,Value * newVal)126   void setArgument(unsigned ArgNo, Value* newVal) {
127     assert(getInstruction() && "Not a call or invoke instruction!");
128     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
129     getInstruction()->setOperand(ArgNo, newVal);
130   }
131 
132   /// Given a value use iterator, returns the argument that corresponds to it.
133   /// Iterator must actually correspond to an argument.
getArgumentNo(Value::const_user_iterator I)134   unsigned getArgumentNo(Value::const_user_iterator I) const {
135     return getArgumentNo(&I.getUse());
136   }
137 
138   /// Given a use for an argument, get the argument number that corresponds to
139   /// it.
getArgumentNo(const Use * U)140   unsigned getArgumentNo(const Use *U) const {
141     assert(getInstruction() && "Not a call or invoke instruction!");
142     assert(arg_begin() <= U && U < arg_end()
143            && "Argument # out of range!");
144     return U - arg_begin();
145   }
146 
147   /// arg_iterator - The type of iterator to use when looping over actual
148   /// arguments at this call site.
149   typedef IterTy arg_iterator;
150 
args()151   iterator_range<IterTy> args() const {
152     return make_range(arg_begin(), arg_end());
153   }
arg_empty()154   bool arg_empty() const { return arg_end() == arg_begin(); }
arg_size()155   unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
156 
157   /// Type of iterator to use when looping over data operands at this call site
158   /// (see below).
159   typedef IterTy data_operand_iterator;
160 
161   /// data_operands_begin/data_operands_end - Return iterators iterating over
162   /// the call / invoke argument list and bundle operands.  For invokes, this is
163   /// the set of instruction operands except the invoke target and the two
164   /// successor blocks; and for calls this is the set of instruction operands
165   /// except the call target.
166 
data_operands_begin()167   IterTy data_operands_begin() const {
168     assert(getInstruction() && "Not a call or invoke instruction!");
169     return (*this)->op_begin();
170   }
data_operands_end()171   IterTy data_operands_end() const {
172     assert(getInstruction() && "Not a call or invoke instruction!");
173     return (*this)->op_end() - (isCall() ? 1 : 3);
174   }
data_ops()175   iterator_range<IterTy> data_ops() const {
176     return make_range(data_operands_begin(), data_operands_end());
177   }
data_operands_empty()178   bool data_operands_empty() const {
179     return data_operands_end() == data_operands_begin();
180   }
data_operands_size()181   unsigned data_operands_size() const {
182     return std::distance(data_operands_begin(), data_operands_end());
183   }
184 
185   /// getType - Return the type of the instruction that generated this call site
186   ///
getType()187   Type *getType() const { return (*this)->getType(); }
188 
189   /// getCaller - Return the caller function for this call site
190   ///
getCaller()191   FunTy *getCaller() const { return (*this)->getParent()->getParent(); }
192 
193   /// \brief Tests if this call site must be tail call optimized.  Only a
194   /// CallInst can be tail call optimized.
isMustTailCall()195   bool isMustTailCall() const {
196     return isCall() && cast<CallInst>(getInstruction())->isMustTailCall();
197   }
198 
199   /// \brief Tests if this call site is marked as a tail call.
isTailCall()200   bool isTailCall() const {
201     return isCall() && cast<CallInst>(getInstruction())->isTailCall();
202   }
203 
204 #define CALLSITE_DELEGATE_GETTER(METHOD) \
205   InstrTy *II = getInstruction();    \
206   return isCall()                        \
207     ? cast<CallInst>(II)->METHOD         \
208     : cast<InvokeInst>(II)->METHOD
209 
210 #define CALLSITE_DELEGATE_SETTER(METHOD) \
211   InstrTy *II = getInstruction();    \
212   if (isCall())                          \
213     cast<CallInst>(II)->METHOD;          \
214   else                                   \
215     cast<InvokeInst>(II)->METHOD
216 
getNumArgOperands()217   unsigned getNumArgOperands() const {
218     CALLSITE_DELEGATE_GETTER(getNumArgOperands());
219   }
220 
getArgOperand(unsigned i)221   ValTy *getArgOperand(unsigned i) const {
222     CALLSITE_DELEGATE_GETTER(getArgOperand(i));
223   }
224 
isInlineAsm()225   bool isInlineAsm() const {
226     if (isCall())
227       return cast<CallInst>(getInstruction())->isInlineAsm();
228     return false;
229   }
230 
231   /// getCallingConv/setCallingConv - get or set the calling convention of the
232   /// call.
getCallingConv()233   CallingConv::ID getCallingConv() const {
234     CALLSITE_DELEGATE_GETTER(getCallingConv());
235   }
setCallingConv(CallingConv::ID CC)236   void setCallingConv(CallingConv::ID CC) {
237     CALLSITE_DELEGATE_SETTER(setCallingConv(CC));
238   }
239 
getFunctionType()240   FunctionType *getFunctionType() const {
241     CALLSITE_DELEGATE_GETTER(getFunctionType());
242   }
243 
mutateFunctionType(FunctionType * Ty)244   void mutateFunctionType(FunctionType *Ty) const {
245     CALLSITE_DELEGATE_SETTER(mutateFunctionType(Ty));
246   }
247 
248   /// getAttributes/setAttributes - get or set the parameter attributes of
249   /// the call.
getAttributes()250   const AttributeSet &getAttributes() const {
251     CALLSITE_DELEGATE_GETTER(getAttributes());
252   }
setAttributes(const AttributeSet & PAL)253   void setAttributes(const AttributeSet &PAL) {
254     CALLSITE_DELEGATE_SETTER(setAttributes(PAL));
255   }
256 
257   /// \brief Return true if this function has the given attribute.
hasFnAttr(Attribute::AttrKind A)258   bool hasFnAttr(Attribute::AttrKind A) const {
259     CALLSITE_DELEGATE_GETTER(hasFnAttr(A));
260   }
261 
262   /// \brief Return true if the call or the callee has the given attribute.
paramHasAttr(unsigned i,Attribute::AttrKind A)263   bool paramHasAttr(unsigned i, Attribute::AttrKind A) const {
264     CALLSITE_DELEGATE_GETTER(paramHasAttr(i, A));
265   }
266 
267   /// \brief Return true if the data operand at index \p i directly or
268   /// indirectly has the attribute \p A.
269   ///
270   /// Normal call or invoke arguments have per operand attributes, as specified
271   /// in the attribute set attached to this instruction, while operand bundle
272   /// operands may have some attributes implied by the type of its containing
273   /// operand bundle.
dataOperandHasImpliedAttr(unsigned i,Attribute::AttrKind A)274   bool dataOperandHasImpliedAttr(unsigned i, Attribute::AttrKind A) const {
275     CALLSITE_DELEGATE_GETTER(dataOperandHasImpliedAttr(i, A));
276   }
277 
278   /// @brief Extract the alignment for a call or parameter (0=unknown).
getParamAlignment(uint16_t i)279   uint16_t getParamAlignment(uint16_t i) const {
280     CALLSITE_DELEGATE_GETTER(getParamAlignment(i));
281   }
282 
283   /// @brief Extract the number of dereferenceable bytes for a call or
284   /// parameter (0=unknown).
getDereferenceableBytes(uint16_t i)285   uint64_t getDereferenceableBytes(uint16_t i) const {
286     CALLSITE_DELEGATE_GETTER(getDereferenceableBytes(i));
287   }
288 
289   /// @brief Extract the number of dereferenceable_or_null bytes for a call or
290   /// parameter (0=unknown).
getDereferenceableOrNullBytes(uint16_t i)291   uint64_t getDereferenceableOrNullBytes(uint16_t i) const {
292     CALLSITE_DELEGATE_GETTER(getDereferenceableOrNullBytes(i));
293   }
294 
295   /// @brief Determine if the parameter or return value is marked with NoAlias
296   /// attribute.
297   /// @param n The parameter to check. 1 is the first parameter, 0 is the return
doesNotAlias(unsigned n)298   bool doesNotAlias(unsigned n) const {
299     CALLSITE_DELEGATE_GETTER(doesNotAlias(n));
300   }
301 
302   /// \brief Return true if the call should not be treated as a call to a
303   /// builtin.
isNoBuiltin()304   bool isNoBuiltin() const {
305     CALLSITE_DELEGATE_GETTER(isNoBuiltin());
306   }
307 
308   /// @brief Return true if the call should not be inlined.
isNoInline()309   bool isNoInline() const {
310     CALLSITE_DELEGATE_GETTER(isNoInline());
311   }
312   void setIsNoInline(bool Value = true) {
313     CALLSITE_DELEGATE_SETTER(setIsNoInline(Value));
314   }
315 
316   /// @brief Determine if the call does not access memory.
doesNotAccessMemory()317   bool doesNotAccessMemory() const {
318     CALLSITE_DELEGATE_GETTER(doesNotAccessMemory());
319   }
setDoesNotAccessMemory()320   void setDoesNotAccessMemory() {
321     CALLSITE_DELEGATE_SETTER(setDoesNotAccessMemory());
322   }
323 
324   /// @brief Determine if the call does not access or only reads memory.
onlyReadsMemory()325   bool onlyReadsMemory() const {
326     CALLSITE_DELEGATE_GETTER(onlyReadsMemory());
327   }
setOnlyReadsMemory()328   void setOnlyReadsMemory() {
329     CALLSITE_DELEGATE_SETTER(setOnlyReadsMemory());
330   }
331 
332   /// @brief Determine if the call can access memmory only using pointers based
333   /// on its arguments.
onlyAccessesArgMemory()334   bool onlyAccessesArgMemory() const {
335     CALLSITE_DELEGATE_GETTER(onlyAccessesArgMemory());
336   }
setOnlyAccessesArgMemory()337   void setOnlyAccessesArgMemory() {
338     CALLSITE_DELEGATE_SETTER(setOnlyAccessesArgMemory());
339   }
340 
341   /// @brief Determine if the call cannot return.
doesNotReturn()342   bool doesNotReturn() const {
343     CALLSITE_DELEGATE_GETTER(doesNotReturn());
344   }
setDoesNotReturn()345   void setDoesNotReturn() {
346     CALLSITE_DELEGATE_SETTER(setDoesNotReturn());
347   }
348 
349   /// @brief Determine if the call cannot unwind.
doesNotThrow()350   bool doesNotThrow() const {
351     CALLSITE_DELEGATE_GETTER(doesNotThrow());
352   }
setDoesNotThrow()353   void setDoesNotThrow() {
354     CALLSITE_DELEGATE_SETTER(setDoesNotThrow());
355   }
356 
getNumOperandBundles()357   int getNumOperandBundles() const {
358     CALLSITE_DELEGATE_GETTER(getNumOperandBundles());
359   }
360 
hasOperandBundles()361   bool hasOperandBundles() const {
362     CALLSITE_DELEGATE_GETTER(hasOperandBundles());
363   }
364 
getNumTotalBundleOperands()365   int getNumTotalBundleOperands() const {
366     CALLSITE_DELEGATE_GETTER(getNumTotalBundleOperands());
367   }
368 
getOperandBundleAt(unsigned Index)369   OperandBundleUse getOperandBundleAt(unsigned Index) const {
370     CALLSITE_DELEGATE_GETTER(getOperandBundleAt(Index));
371   }
372 
getOperandBundle(StringRef Name)373   Optional<OperandBundleUse> getOperandBundle(StringRef Name) const {
374     CALLSITE_DELEGATE_GETTER(getOperandBundle(Name));
375   }
376 
getOperandBundle(uint32_t ID)377   Optional<OperandBundleUse> getOperandBundle(uint32_t ID) const {
378     CALLSITE_DELEGATE_GETTER(getOperandBundle(ID));
379   }
380 
arg_begin()381   IterTy arg_begin() const {
382     CALLSITE_DELEGATE_GETTER(arg_begin());
383   }
384 
arg_end()385   IterTy arg_end() const {
386     CALLSITE_DELEGATE_GETTER(arg_end());
387   }
388 
389 #undef CALLSITE_DELEGATE_GETTER
390 #undef CALLSITE_DELEGATE_SETTER
391 
getOperandBundlesAsDefs(SmallVectorImpl<OperandBundleDef> & Defs)392   void getOperandBundlesAsDefs(SmallVectorImpl<OperandBundleDef> &Defs) const {
393     const Instruction *II = getInstruction();
394     // Since this is actually a getter that "looks like" a setter, don't use the
395     // above macros to avoid confusion.
396     if (isCall())
397       cast<CallInst>(II)->getOperandBundlesAsDefs(Defs);
398     else
399       cast<InvokeInst>(II)->getOperandBundlesAsDefs(Defs);
400   }
401 
402   /// @brief Determine whether this data operand is not captured.
doesNotCapture(unsigned OpNo)403   bool doesNotCapture(unsigned OpNo) const {
404     return dataOperandHasImpliedAttr(OpNo + 1, Attribute::NoCapture);
405   }
406 
407   /// @brief Determine whether this argument is passed by value.
isByValArgument(unsigned ArgNo)408   bool isByValArgument(unsigned ArgNo) const {
409     return paramHasAttr(ArgNo + 1, Attribute::ByVal);
410   }
411 
412   /// @brief Determine whether this argument is passed in an alloca.
isInAllocaArgument(unsigned ArgNo)413   bool isInAllocaArgument(unsigned ArgNo) const {
414     return paramHasAttr(ArgNo + 1, Attribute::InAlloca);
415   }
416 
417   /// @brief Determine whether this argument is passed by value or in an alloca.
isByValOrInAllocaArgument(unsigned ArgNo)418   bool isByValOrInAllocaArgument(unsigned ArgNo) const {
419     return paramHasAttr(ArgNo + 1, Attribute::ByVal) ||
420            paramHasAttr(ArgNo + 1, Attribute::InAlloca);
421   }
422 
423   /// @brief Determine if there are is an inalloca argument.  Only the last
424   /// argument can have the inalloca attribute.
hasInAllocaArgument()425   bool hasInAllocaArgument() const {
426     return paramHasAttr(arg_size(), Attribute::InAlloca);
427   }
428 
doesNotAccessMemory(unsigned OpNo)429   bool doesNotAccessMemory(unsigned OpNo) const {
430     return dataOperandHasImpliedAttr(OpNo + 1, Attribute::ReadNone);
431   }
432 
onlyReadsMemory(unsigned OpNo)433   bool onlyReadsMemory(unsigned OpNo) const {
434     return dataOperandHasImpliedAttr(OpNo + 1, Attribute::ReadOnly) ||
435            dataOperandHasImpliedAttr(OpNo + 1, Attribute::ReadNone);
436   }
437 
438   /// @brief Return true if the return value is known to be not null.
439   /// This may be because it has the nonnull attribute, or because at least
440   /// one byte is dereferenceable and the pointer is in addrspace(0).
isReturnNonNull()441   bool isReturnNonNull() const {
442     if (paramHasAttr(0, Attribute::NonNull))
443       return true;
444     else if (getDereferenceableBytes(0) > 0 &&
445              getType()->getPointerAddressSpace() == 0)
446       return true;
447 
448     return false;
449   }
450 
451   /// hasArgument - Returns true if this CallSite passes the given Value* as an
452   /// argument to the called function.
hasArgument(const Value * Arg)453   bool hasArgument(const Value *Arg) const {
454     for (arg_iterator AI = this->arg_begin(), E = this->arg_end(); AI != E;
455          ++AI)
456       if (AI->get() == Arg)
457         return true;
458     return false;
459   }
460 
461 private:
getCallee()462   IterTy getCallee() const {
463     if (isCall()) // Skip Callee
464       return cast<CallInst>(getInstruction())->op_end() - 1;
465     else // Skip BB, BB, Callee
466       return cast<InvokeInst>(getInstruction())->op_end() - 3;
467   }
468 };
469 
470 class CallSite : public CallSiteBase<Function, BasicBlock, Value, User, Use,
471                                      Instruction, CallInst, InvokeInst,
472                                      User::op_iterator> {
473 public:
CallSite()474   CallSite() {}
CallSite(CallSiteBase B)475   CallSite(CallSiteBase B) : CallSiteBase(B) {}
CallSite(CallInst * CI)476   CallSite(CallInst *CI) : CallSiteBase(CI) {}
CallSite(InvokeInst * II)477   CallSite(InvokeInst *II) : CallSiteBase(II) {}
CallSite(Instruction * II)478   explicit CallSite(Instruction *II) : CallSiteBase(II) {}
CallSite(Value * V)479   explicit CallSite(Value *V) : CallSiteBase(V) {}
480 
481   bool operator==(const CallSite &CS) const { return I == CS.I; }
482   bool operator!=(const CallSite &CS) const { return I != CS.I; }
483   bool operator<(const CallSite &CS) const {
484     return getInstruction() < CS.getInstruction();
485   }
486 
487 private:
488   User::op_iterator getCallee() const;
489 };
490 
491 /// ImmutableCallSite - establish a view to a call site for examination
492 class ImmutableCallSite : public CallSiteBase<> {
493 public:
ImmutableCallSite()494   ImmutableCallSite() {}
ImmutableCallSite(const CallInst * CI)495   ImmutableCallSite(const CallInst *CI) : CallSiteBase(CI) {}
ImmutableCallSite(const InvokeInst * II)496   ImmutableCallSite(const InvokeInst *II) : CallSiteBase(II) {}
ImmutableCallSite(const Instruction * II)497   explicit ImmutableCallSite(const Instruction *II) : CallSiteBase(II) {}
ImmutableCallSite(const Value * V)498   explicit ImmutableCallSite(const Value *V) : CallSiteBase(V) {}
ImmutableCallSite(CallSite CS)499   ImmutableCallSite(CallSite CS) : CallSiteBase(CS.getInstruction()) {}
500 };
501 
502 } // End llvm namespace
503 
504 #endif
505