CallSite.h revision 08e78b18b8ef2c939ee95469662c98e23846d860 
1//===-- llvm/Support/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.
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(Instruction *C);
40  CallSite(const CallSite &CS) : I(CS.I) {}
41  CallSite &operator=(const CallSite &CS) { I = CS.I; return *this; }
42
43  /// CallSite::get - This static method is sort of like a constructor.  It will
44  /// create an appropriate call site for a Call or Invoke instruction, but it
45  /// can also create a null initialized CallSite object for something which is
46  /// NOT a call site.
47  ///
48  static CallSite get(Value *V) {
49    if (Instruction *I = dyn_cast<Instruction>(V)) {
50      if (I->getOpcode() == Instruction::Call)
51        return CallSite(reinterpret_cast<CallInst*>(I));
52      else if (I->getOpcode() == Instruction::Invoke)
53        return CallSite(reinterpret_cast<InvokeInst*>(I));
54    }
55    return CallSite();
56  }
57
58  /// getCallingConv/setCallingConv - get or set the calling convention of the
59  /// call.
60  unsigned getCallingConv() const;
61  void setCallingConv(unsigned CC);
62
63  /// getParamAttrs/setParamAttrs - get or set the parameter attributes of
64  /// the call.
65  const ParamAttrsList *getParamAttrs() const;
66  void setParamAttrs(const ParamAttrsList *PAL);
67
68  /// paramHasAttr - whether the call or the callee has the given attribute.
69  bool paramHasAttr(uint16_t i, ParameterAttributes attr) const;
70
71  /// @brief Extract the alignment for a call or parameter (0=unknown).
72  uint16_t getParamAlignment(uint16_t i) const;
73
74  /// @brief Determine if the call does not access memory.
75  bool doesNotAccessMemory() const;
76
77  /// @brief Determine if the call does not access or only reads memory.
78  bool onlyReadsMemory() const;
79
80  /// @brief Determine if the call cannot unwind.
81  bool doesNotThrow() const;
82  void setDoesNotThrow(bool doesNotThrow = true);
83
84  /// getType - Return the type of the instruction that generated this call site
85  ///
86  const Type *getType() const { return I->getType(); }
87
88  /// getInstruction - Return the instruction this call site corresponds to
89  ///
90  Instruction *getInstruction() const { return I; }
91
92  /// getCaller - Return the caller function for this call site
93  ///
94  Function *getCaller() const { return I->getParent()->getParent(); }
95
96  /// getCalledValue - Return the pointer to function that is being called...
97  ///
98  Value *getCalledValue() const {
99    assert(I && "Not a call or invoke instruction!");
100    return I->getOperand(0);
101  }
102
103  /// getCalledFunction - Return the function being called if this is a direct
104  /// call, otherwise return null (if it's an indirect call).
105  ///
106  Function *getCalledFunction() const {
107    return dyn_cast<Function>(getCalledValue());
108  }
109
110  /// setCalledFunction - Set the callee to the specified value...
111  ///
112  void setCalledFunction(Value *V) {
113    assert(I && "Not a call or invoke instruction!");
114    I->setOperand(0, V);
115  }
116
117  Value *getArgument(unsigned ArgNo) const {
118    assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
119    return *(arg_begin()+ArgNo);
120  }
121
122  void setArgument(unsigned ArgNo, Value* newVal) {
123    assert(I && "Not a call or invoke instruction!");
124    assert(arg_begin() + ArgNo < arg_end() && "Argument # out of range!");
125    if (I->getOpcode() == Instruction::Call)
126      I->setOperand(ArgNo+1, newVal); // Skip Function
127    else
128      I->setOperand(ArgNo+3, newVal); // Skip Function, BB, BB
129  }
130
131  /// arg_iterator - The type of iterator to use when looping over actual
132  /// arguments at this call site...
133  typedef User::op_iterator arg_iterator;
134
135  /// arg_begin/arg_end - Return iterators corresponding to the actual argument
136  /// list for a call site.
137  ///
138  arg_iterator arg_begin() const {
139    assert(I && "Not a call or invoke instruction!");
140    if (I->getOpcode() == Instruction::Call)
141      return I->op_begin()+1; // Skip Function
142    else
143      return I->op_begin()+3; // Skip Function, BB, BB
144  }
145  arg_iterator arg_end() const { return I->op_end(); }
146  bool arg_empty() const { return arg_end() == arg_begin(); }
147  unsigned arg_size() const { return unsigned(arg_end() - arg_begin()); }
148
149  bool operator<(const CallSite &CS) const {
150    return getInstruction() < CS.getInstruction();
151  }
152};
153
154} // End llvm namespace
155
156#endif
157