CallSite.h revision ece2c04d532d46405c085769d03173b392813eb3 
1//===-- llvm/Support/CallSite.h - Abstract Call & Invoke instrs -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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.
12//
13// NOTE: This class is supposed to have "value semantics". So it should be
14// passed by value, not by reference; it should not be "new"ed or "delete"d. It
15// is efficiently copyable, assignable and constructable, with cost equivalent
16// to copying a pointer (notice that it has only a single data member).
17//
18//===----------------------------------------------------------------------===//
19
20#ifndef LLVM_SUPPORT_CALLSITE_H
21#define LLVM_SUPPORT_CALLSITE_H
22
23#include "llvm/Instruction.h"
24#include "llvm/BasicBlock.h"
25#include "llvm/ParameterAttributes.h"
26
27namespace llvm {
28
29class CallInst;
30class InvokeInst;
31class ParamAttrsList;
32
33class CallSite {
34  Instruction *I;
35public:
36  CallSite() : I(0) {}
37  CallSite(CallInst *CI) : I(reinterpret_cast<Instruction*>(CI)) {}
38  CallSite(InvokeInst *II) : I(reinterpret_cast<Instruction*>(II)) {}
39  CallSite(const CallSite &CS) : I(CS.I) {}
40  CallSite &operator=(const CallSite &CS) { I = CS.I; return *this; }
41
42  /// CallSite::get - This static method is sort of like a constructor.  It will
43  /// create an appropriate call site for a Call or Invoke instruction, but it
44  /// can also create a null initialized CallSite object for something which is
45  /// NOT a call site.
46  ///
47  static CallSite get(Value *V) {
48    if (Instruction *I = dyn_cast<Instruction>(V)) {
49      if (I->getOpcode() == Instruction::Call)
50        return CallSite(reinterpret_cast<CallInst*>(I));
51      else if (I->getOpcode() == Instruction::Invoke)
52        return CallSite(reinterpret_cast<InvokeInst*>(I));
53    }
54    return CallSite();
55  }
56
57  /// getCallingConv/setCallingConv - get or set the calling convention of the
58  /// call.
59  unsigned getCallingConv() const;
60  void setCallingConv(unsigned CC);
61
62  /// getParamAttrs/setParamAttrs - get or set the parameter attributes of
63  /// the call.
64  const ParamAttrsList *getParamAttrs() const;
65  void setParamAttrs(const ParamAttrsList *PAL);
66
67  /// paramHasAttr - whether the call or the callee has the given attribute.
68  bool paramHasAttr(uint16_t i, ParameterAttributes attr) const;
69
70  /// @brief Determine if the call does not access memory.
71  bool doesNotAccessMemory() const;
72
73  /// @brief Determine if the call does not access or only reads memory.
74  bool onlyReadsMemory() const;
75
76  /// @brief Determine if the call cannot unwind.
77  bool isNoUnwind() const;
78
79  /// getType - Return the type of the instruction that generated this call site
80  ///
81  const Type *getType() const { return I->getType(); }
82
83  /// getInstruction - Return the instruction this call site corresponds to
84  ///
85  Instruction *getInstruction() const { return I; }
86
87  /// getCaller - Return the caller function for this call site
88  ///
89  Function *getCaller() const { return I->getParent()->getParent(); }
90
91  /// getCalledValue - Return the pointer to function that is being called...
92  ///
93  Value *getCalledValue() const {
94    assert(I && "Not a call or invoke instruction!");
95    return I->getOperand(0);
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  ///
101  Function *getCalledFunction() const {
102    return dyn_cast<Function>(getCalledValue());
103  }
104
105  /// setCalledFunction - Set the callee to the specified value...
106  ///
107  void setCalledFunction(Value *V) {
108    assert(I && "Not a call or invoke instruction!");
109    I->setOperand(0, V);
110  }
111
112  Value *getArgument(unsigned ArgNo) const {
113    assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
114    return *(arg_begin()+ArgNo);
115  }
116
117  /// arg_iterator - The type of iterator to use when looping over actual
118  /// arguments at this call site...
119  typedef User::op_iterator arg_iterator;
120
121  /// arg_begin/arg_end - Return iterators corresponding to the actual argument
122  /// list for a call site.
123  ///
124  arg_iterator arg_begin() const {
125    assert(I && "Not a call or invoke instruction!");
126    if (I->getOpcode() == Instruction::Call)
127      return I->op_begin()+1; // Skip Function
128    else
129      return I->op_begin()+3; // Skip Function, BB, BB
130  }
131  arg_iterator arg_end() const { return I->op_end(); }
132  bool arg_empty() const { return arg_end() == arg_begin(); }
133  unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
134
135  bool operator<(const CallSite &CS) const {
136    return getInstruction() < CS.getInstruction();
137  }
138};
139
140} // End llvm namespace
141
142#endif
143