1//===- InstIterator.h - Classes for inst iteration --------------*- 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 contains definitions of two iterators for iterating over the
11// instructions in a function.  This is effectively a wrapper around a two level
12// iterator that can probably be genericized later.
13//
14// Note that this iterator gets invalidated any time that basic blocks or
15// instructions are moved around.
16//
17//===----------------------------------------------------------------------===//
18
19#ifndef LLVM_IR_INSTITERATOR_H
20#define LLVM_IR_INSTITERATOR_H
21
22#include "llvm/IR/BasicBlock.h"
23#include "llvm/IR/Function.h"
24
25namespace llvm {
26
27// This class implements inst_begin() & inst_end() for
28// inst_iterator and const_inst_iterator's.
29//
30template <class BB_t, class BB_i_t, class BI_t, class II_t> class InstIterator {
31  typedef BB_t BBty;
32  typedef BB_i_t BBIty;
33  typedef BI_t BIty;
34  typedef II_t IIty;
35  BB_t *BBs; // BasicBlocksType
36  BB_i_t BB; // BasicBlocksType::iterator
37  BI_t BI;   // BasicBlock::iterator
38public:
39  typedef std::bidirectional_iterator_tag iterator_category;
40  typedef IIty                            value_type;
41  typedef signed                        difference_type;
42  typedef IIty*                           pointer;
43  typedef IIty&                           reference;
44
45  // Default constructor
46  InstIterator() {}
47
48  // Copy constructor...
49  template<typename A, typename B, typename C, typename D>
50  InstIterator(const InstIterator<A,B,C,D> &II)
51    : BBs(II.BBs), BB(II.BB), BI(II.BI) {}
52
53  template<typename A, typename B, typename C, typename D>
54  InstIterator(InstIterator<A,B,C,D> &II)
55    : BBs(II.BBs), BB(II.BB), BI(II.BI) {}
56
57  template<class M> InstIterator(M &m)
58    : BBs(&m.getBasicBlockList()), BB(BBs->begin()) {    // begin ctor
59    if (BB != BBs->end()) {
60      BI = BB->begin();
61      advanceToNextBB();
62    }
63  }
64
65  template<class M> InstIterator(M &m, bool)
66    : BBs(&m.getBasicBlockList()), BB(BBs->end()) {    // end ctor
67  }
68
69  // Accessors to get at the underlying iterators...
70  inline BBIty &getBasicBlockIterator()  { return BB; }
71  inline BIty  &getInstructionIterator() { return BI; }
72
73  inline reference operator*()  const { return *BI; }
74  inline pointer operator->() const { return &operator*(); }
75
76  inline bool operator==(const InstIterator &y) const {
77    return BB == y.BB && (BB == BBs->end() || BI == y.BI);
78  }
79  inline bool operator!=(const InstIterator& y) const {
80    return !operator==(y);
81  }
82
83  InstIterator& operator++() {
84    ++BI;
85    advanceToNextBB();
86    return *this;
87  }
88  inline InstIterator operator++(int) {
89    InstIterator tmp = *this; ++*this; return tmp;
90  }
91
92  InstIterator& operator--() {
93    while (BB == BBs->end() || BI == BB->begin()) {
94      --BB;
95      BI = BB->end();
96    }
97    --BI;
98    return *this;
99  }
100  inline InstIterator  operator--(int) {
101    InstIterator tmp = *this; --*this; return tmp;
102  }
103
104  inline bool atEnd() const { return BB == BBs->end(); }
105
106private:
107  inline void advanceToNextBB() {
108    // The only way that the II could be broken is if it is now pointing to
109    // the end() of the current BasicBlock and there are successor BBs.
110    while (BI == BB->end()) {
111      ++BB;
112      if (BB == BBs->end()) break;
113      BI = BB->begin();
114    }
115  }
116};
117
118
119typedef InstIterator<iplist<BasicBlock>,
120                     Function::iterator, BasicBlock::iterator,
121                     Instruction> inst_iterator;
122typedef InstIterator<const iplist<BasicBlock>,
123                     Function::const_iterator,
124                     BasicBlock::const_iterator,
125                     const Instruction> const_inst_iterator;
126
127inline inst_iterator inst_begin(Function *F) { return inst_iterator(*F); }
128inline inst_iterator inst_end(Function *F)   { return inst_iterator(*F, true); }
129inline iterator_range<inst_iterator> inst_range(Function *F) {
130  return iterator_range<inst_iterator>(inst_begin(F), inst_end(F));
131}
132inline const_inst_iterator inst_begin(const Function *F) {
133  return const_inst_iterator(*F);
134}
135inline const_inst_iterator inst_end(const Function *F) {
136  return const_inst_iterator(*F, true);
137}
138inline iterator_range<const_inst_iterator> inst_range(const Function *F) {
139  return iterator_range<const_inst_iterator>(inst_begin(F), inst_end(F));
140}
141inline inst_iterator inst_begin(Function &F) { return inst_iterator(F); }
142inline inst_iterator inst_end(Function &F)   { return inst_iterator(F, true); }
143inline iterator_range<inst_iterator> inst_range(Function &F) {
144  return iterator_range<inst_iterator>(inst_begin(F), inst_end(F));
145}
146inline const_inst_iterator inst_begin(const Function &F) {
147  return const_inst_iterator(F);
148}
149inline const_inst_iterator inst_end(const Function &F) {
150  return const_inst_iterator(F, true);
151}
152inline iterator_range<const_inst_iterator> inst_range(const Function &F) {
153  return iterator_range<const_inst_iterator>(inst_begin(F), inst_end(F));
154}
155
156} // End llvm namespace
157
158#endif
159