src/llvm/include/llvm/IR/CallSite.h

   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/IR/Attributes.h"
  31 #include "llvm/IR/CallingConv.h"
  32 #include "llvm/IR/Instructions.h"
  33
  34 namespace llvm {
  35
  36 class CallInst;
  37 class InvokeInst;
  38
  39 template <typename FunTy = const Function,
  40           typename ValTy = const Value,
  41           typename UserTy = const User,
  42           typename InstrTy = const Instruction,
  43           typename CallTy = const CallInst,
  44           typename InvokeTy = const InvokeInst,
  45           typename IterTy = User::const_op_iterator>
  46 class CallSiteBase {
  47 protected:
  48   PointerIntPair<InstrTy*, 1, bool> I;
  49 public:
  50   CallSiteBase() : I(nullptr, false) {}
  51   CallSiteBase(CallTy *CI) : I(CI, true) { assert(CI); }
  52   CallSiteBase(InvokeTy *II) : I(II, false) { assert(II); }
  53   CallSiteBase(ValTy *II) { *this = get(II); }
  54 protected:
  55   /// CallSiteBase::get - This static method is sort of like a constructor.  It
  56   /// will create an appropriate call site for a Call or Invoke instruction, but
  57   /// it can also create a null initialized CallSiteBase object for something
  58   /// which is NOT a call site.
  59   ///
  60   static CallSiteBase get(ValTy *V) {
  61     if (InstrTy *II = dyn_cast<InstrTy>(V)) {
  62       if (II->getOpcode() == Instruction::Call)
  63         return CallSiteBase(static_cast<CallTy*>(II));
  64       else if (II->getOpcode() == Instruction::Invoke)
  65         return CallSiteBase(static_cast<InvokeTy*>(II));
  66     }
  67     return CallSiteBase();
  68   }
  69 public:
  70   /// isCall - true if a CallInst is enclosed.
  71   /// Note that !isCall() does not mean it is an InvokeInst enclosed,
  72   /// it also could signify a NULL Instruction pointer.
  73   bool isCall() const { return I.getInt(); }
  74
  75   /// isInvoke - true if a InvokeInst is enclosed.
  76   ///
  77   bool isInvoke() const { return getInstruction() && !I.getInt(); }
  78
  79   InstrTy *getInstruction() const { return I.getPointer(); }
  80   InstrTy *operator->() const { return I.getPointer(); }
  81   LLVM_EXPLICIT operator bool() const { return I.getPointer(); }
  82
  83   /// getCalledValue - Return the pointer to function that is being called.
  84   ///
  85   ValTy *getCalledValue() const {
  86     assert(getInstruction() && "Not a call or invoke instruction!");
  87     return *getCallee();
  88   }
  89
  90   /// getCalledFunction - Return the function being called if this is a direct
  91   /// call, otherwise return null (if it's an indirect call).
  92   ///
  93   FunTy *getCalledFunction() const {
  94     return dyn_cast<FunTy>(getCalledValue());
  95   }
  96
  97   /// setCalledFunction - Set the callee to the specified value.
  98   ///
  99   void setCalledFunction(Value *V) {
 100     assert(getInstruction() && "Not a call or invoke instruction!");
 101     *getCallee() = V;
 102   }
 103
 104   /// isCallee - Determine whether the passed iterator points to the
 105   /// callee operand's Use.
 106   bool isCallee(Value::const_user_iterator UI) const {
 107     return isCallee(&UI.getUse());
 108   }
 109
 110   /// Determine whether this Use is the callee operand's Use.
 111   bool isCallee(const Use *U) const { return getCallee() == U; }
 112
 113   ValTy *getArgument(unsigned ArgNo) const {
 114     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
 115     return *(arg_begin() + ArgNo);
 116   }
 117
 118   void setArgument(unsigned ArgNo, Value* newVal) {
 119     assert(getInstruction() && "Not a call or invoke instruction!");
 120     assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
 121     getInstruction()->setOperand(ArgNo, newVal);
 122   }
 123
 124   /// Given a value use iterator, returns the argument that corresponds to it.
 125   /// Iterator must actually correspond to an argument.
 126   unsigned getArgumentNo(Value::const_user_iterator I) const {
 127     return getArgumentNo(&I.getUse());
 128   }
 129
 130   /// Given a use for an argument, get the argument number that corresponds to
 131   /// it.
 132   unsigned getArgumentNo(const Use *U) const {
 133     assert(getInstruction() && "Not a call or invoke instruction!");
 134     assert(arg_begin() <= U && U < arg_end()
 135            && "Argument # out of range!");
 136     return U - arg_begin();
 137   }
 138
 139   /// arg_iterator - The type of iterator to use when looping over actual
 140   /// arguments at this call site.
 141   typedef IterTy arg_iterator;
 142
 143   /// arg_begin/arg_end - Return iterators corresponding to the actual argument
 144   /// list for a call site.
 145   IterTy arg_begin() const {
 146     assert(getInstruction() && "Not a call or invoke instruction!");
 147     // Skip non-arguments
 148     return (*this)->op_begin();
 149   }
 150
 151   IterTy arg_end() const { return (*this)->op_end() - getArgumentEndOffset(); }
 152   bool arg_empty() const { return arg_end() == arg_begin(); }
 153   unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
 154
 155   /// getType - Return the type of the instruction that generated this call site
 156   ///
 157   Type *getType() const { return (*this)->getType(); }
 158
 159   /// getCaller - Return the caller function for this call site
 160   ///
 161   FunTy *getCaller() const { return (*this)->getParent()->getParent(); }
 162
 163   /// \brief Tests if this call site must be tail call optimized.  Only a
 164   /// CallInst can be tail call optimized.
 165   bool isMustTailCall() const {
 166     return isCall() && cast<CallInst>(getInstruction())->isMustTailCall();
 167   }
 168
 169   /// \brief Tests if this call site is marked as a tail call.
 170   bool isTailCall() const {
 171     return isCall() && cast<CallInst>(getInstruction())->isTailCall();
 172   }
 173
 174 #define CALLSITE_DELEGATE_GETTER(METHOD) \
 175   InstrTy *II = getInstruction();    \
 176   return isCall()                        \
 177     ? cast<CallInst>(II)->METHOD         \
 178     : cast<InvokeInst>(II)->METHOD
 179
 180 #define CALLSITE_DELEGATE_SETTER(METHOD) \
 181   InstrTy *II = getInstruction();    \
 182   if (isCall())                          \
 183     cast<CallInst>(II)->METHOD;          \
 184   else                                   \
 185     cast<InvokeInst>(II)->METHOD
 186
 187   /// getCallingConv/setCallingConv - get or set the calling convention of the
 188   /// call.
 189   CallingConv::ID getCallingConv() const {
 190     CALLSITE_DELEGATE_GETTER(getCallingConv());
 191   }
 192   void setCallingConv(CallingConv::ID CC) {
 193     CALLSITE_DELEGATE_SETTER(setCallingConv(CC));
 194   }
 195
 196   /// getAttributes/setAttributes - get or set the parameter attributes of
 197   /// the call.
 198   const AttributeSet &getAttributes() const {
 199     CALLSITE_DELEGATE_GETTER(getAttributes());
 200   }
 201   void setAttributes(const AttributeSet &PAL) {
 202     CALLSITE_DELEGATE_SETTER(setAttributes(PAL));
 203   }
 204
 205   /// \brief Return true if this function has the given attribute.
 206   bool hasFnAttr(Attribute::AttrKind A) const {
 207     CALLSITE_DELEGATE_GETTER(hasFnAttr(A));
 208   }
 209
 210   /// \brief Return true if the call or the callee has the given attribute.
 211   bool paramHasAttr(unsigned i, Attribute::AttrKind A) const {
 212     CALLSITE_DELEGATE_GETTER(paramHasAttr(i, A));
 213   }
 214
 215   /// @brief Extract the alignment for a call or parameter (0=unknown).
 216   uint16_t getParamAlignment(uint16_t i) const {
 217     CALLSITE_DELEGATE_GETTER(getParamAlignment(i));
 218   }
 219
 220   /// @brief Extract the number of dereferenceable bytes for a call or
 221   /// parameter (0=unknown).
 222   uint64_t getDereferenceableBytes(uint16_t i) const {
 223     CALLSITE_DELEGATE_GETTER(getDereferenceableBytes(i));
 224   }
 225
 226   /// \brief Return true if the call should not be treated as a call to a
 227   /// builtin.
 228   bool isNoBuiltin() const {
 229     CALLSITE_DELEGATE_GETTER(isNoBuiltin());
 230   }
 231
 232   /// @brief Return true if the call should not be inlined.
 233   bool isNoInline() const {
 234     CALLSITE_DELEGATE_GETTER(isNoInline());
 235   }
 236   void setIsNoInline(bool Value = true) {
 237     CALLSITE_DELEGATE_SETTER(setIsNoInline(Value));
 238   }
 239
 240   /// @brief Determine if the call does not access memory.
 241   bool doesNotAccessMemory() const {
 242     CALLSITE_DELEGATE_GETTER(doesNotAccessMemory());
 243   }
 244   void setDoesNotAccessMemory() {
 245     CALLSITE_DELEGATE_SETTER(setDoesNotAccessMemory());
 246   }
 247
 248   /// @brief Determine if the call does not access or only reads memory.
 249   bool onlyReadsMemory() const {
 250     CALLSITE_DELEGATE_GETTER(onlyReadsMemory());
 251   }
 252   void setOnlyReadsMemory() {
 253     CALLSITE_DELEGATE_SETTER(setOnlyReadsMemory());
 254   }
 255
 256   /// @brief Determine if the call cannot return.
 257   bool doesNotReturn() const {
 258     CALLSITE_DELEGATE_GETTER(doesNotReturn());
 259   }
 260   void setDoesNotReturn() {
 261     CALLSITE_DELEGATE_SETTER(setDoesNotReturn());
 262   }
 263
 264   /// @brief Determine if the call cannot unwind.
 265   bool doesNotThrow() const {
 266     CALLSITE_DELEGATE_GETTER(doesNotThrow());
 267   }
 268   void setDoesNotThrow() {
 269     CALLSITE_DELEGATE_SETTER(setDoesNotThrow());
 270   }
 271
 272 #undef CALLSITE_DELEGATE_GETTER
 273 #undef CALLSITE_DELEGATE_SETTER
 274
 275   /// @brief Determine whether this argument is not captured.
 276   bool doesNotCapture(unsigned ArgNo) const {
 277     return paramHasAttr(ArgNo + 1, Attribute::NoCapture);
 278   }
 279
 280   /// @brief Determine whether this argument is passed by value.
 281   bool isByValArgument(unsigned ArgNo) const {
 282     return paramHasAttr(ArgNo + 1, Attribute::ByVal);
 283   }
 284
 285   /// @brief Determine whether this argument is passed in an alloca.
 286   bool isInAllocaArgument(unsigned ArgNo) const {
 287     return paramHasAttr(ArgNo + 1, Attribute::InAlloca);
 288   }
 289
 290   /// @brief Determine whether this argument is passed by value or in an alloca.
 291   bool isByValOrInAllocaArgument(unsigned ArgNo) const {
 292     return paramHasAttr(ArgNo + 1, Attribute::ByVal) ||
 293            paramHasAttr(ArgNo + 1, Attribute::InAlloca);
 294   }
 295
 296   /// @brief Determine if there are is an inalloca argument.  Only the last
 297   /// argument can have the inalloca attribute.
 298   bool hasInAllocaArgument() const {
 299     return paramHasAttr(arg_size(), Attribute::InAlloca);
 300   }
 301
 302   bool doesNotAccessMemory(unsigned ArgNo) const {
 303     return paramHasAttr(ArgNo + 1, Attribute::ReadNone);
 304   }
 305
 306   bool onlyReadsMemory(unsigned ArgNo) const {
 307     return paramHasAttr(ArgNo + 1, Attribute::ReadOnly) ||
 308            paramHasAttr(ArgNo + 1, Attribute::ReadNone);
 309   }
 310
 311   /// @brief Return true if the return value is known to be not null.
 312   /// This may be because it has the nonnull attribute, or because at least
 313   /// one byte is dereferenceable and the pointer is in addrspace(0).
 314   bool isReturnNonNull() const {
 315     if (paramHasAttr(0, Attribute::NonNull))
 316       return true;
 317     else if (getDereferenceableBytes(0) > 0 &&
 318              getType()->getPointerAddressSpace() == 0)
 319       return true;
 320
 321     return false;
 322   }
 323
 324   /// hasArgument - Returns true if this CallSite passes the given Value* as an
 325   /// argument to the called function.
 326   bool hasArgument(const Value *Arg) const {
 327     for (arg_iterator AI = this->arg_begin(), E = this->arg_end(); AI != E;
 328          ++AI)
 329       if (AI->get() == Arg)
 330         return true;
 331     return false;
 332   }
 333
 334 private:
 335   unsigned getArgumentEndOffset() const {
 336     if (isCall())
 337       return 1; // Skip Callee
 338     else
 339       return 3; // Skip BB, BB, Callee
 340   }
 341
 342   IterTy getCallee() const {
 343     if (isCall()) // Skip Callee
 344       return cast<CallInst>(getInstruction())->op_end() - 1;
 345     else // Skip BB, BB, Callee
 346       return cast<InvokeInst>(getInstruction())->op_end() - 3;
 347   }
 348 };
 349
 350 class CallSite : public CallSiteBase<Function, Value, User, Instruction,
 351                                      CallInst, InvokeInst, User::op_iterator> {
 352   typedef CallSiteBase<Function, Value, User, Instruction,
 353                        CallInst, InvokeInst, User::op_iterator> Base;
 354 public:
 355   CallSite() {}
 356   CallSite(Base B) : Base(B) {}
 357   CallSite(Value* V) : Base(V) {}
 358   CallSite(CallInst *CI) : Base(CI) {}
 359   CallSite(InvokeInst *II) : Base(II) {}
 360   CallSite(Instruction *II) : Base(II) {}
 361
 362   bool operator==(const CallSite &CS) const { return I == CS.I; }
 363   bool operator!=(const CallSite &CS) const { return I != CS.I; }
 364   bool operator<(const CallSite &CS) const {
 365     return getInstruction() < CS.getInstruction();
 366   }
 367
 368 private:
 369   User::op_iterator getCallee() const;
 370 };
 371
 372 /// ImmutableCallSite - establish a view to a call site for examination
 373 class ImmutableCallSite : public CallSiteBase<> {
 374   typedef CallSiteBase<> Base;
 375 public:
 376   ImmutableCallSite(const Value* V) : Base(V) {}
 377   ImmutableCallSite(const CallInst *CI) : Base(CI) {}
 378   ImmutableCallSite(const InvokeInst *II) : Base(II) {}
 379   ImmutableCallSite(const Instruction *II) : Base(II) {}
 380   ImmutableCallSite(CallSite CS) : Base(CS.getInstruction()) {}
 381 };
 382
 383 } // End llvm namespace
 384
 385 #endif