1 //===- llvm/Support/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_SUPPORT_INSTITERATOR_H
20 #define LLVM_SUPPORT_INSTITERATOR_H
21
22 #include "llvm/BasicBlock.h"
23 #include "llvm/Function.h"
24
25 namespace llvm {
26
27 // This class implements inst_begin() & inst_end() for
28 // inst_iterator and const_inst_iterator's.
29 //
30 template <class _BB_t, class _BB_i_t, class _BI_t, class _II_t>
31 class InstIterator {
32 typedef _BB_t BBty;
33 typedef _BB_i_t BBIty;
34 typedef _BI_t BIty;
35 typedef _II_t IIty;
36 _BB_t *BBs; // BasicBlocksType
37 _BB_i_t BB; // BasicBlocksType::iterator
38 _BI_t BI; // BasicBlock::iterator
39 public:
40 typedef std::bidirectional_iterator_tag iterator_category;
41 typedef IIty value_type;
42 typedef signed difference_type;
43 typedef IIty* pointer;
44 typedef IIty& reference;
45
46 // Default constructor
InstIterator()47 InstIterator() {}
48
49 // Copy constructor...
50 template<typename A, typename B, typename C, typename D>
InstIterator(const InstIterator<A,B,C,D> & II)51 InstIterator(const InstIterator<A,B,C,D> &II)
52 : BBs(II.BBs), BB(II.BB), BI(II.BI) {}
53
54 template<typename A, typename B, typename C, typename D>
InstIterator(InstIterator<A,B,C,D> & II)55 InstIterator(InstIterator<A,B,C,D> &II)
56 : BBs(II.BBs), BB(II.BB), BI(II.BI) {}
57
InstIterator(M & m)58 template<class M> InstIterator(M &m)
59 : BBs(&m.getBasicBlockList()), BB(BBs->begin()) { // begin ctor
60 if (BB != BBs->end()) {
61 BI = BB->begin();
62 advanceToNextBB();
63 }
64 }
65
InstIterator(M & m,bool)66 template<class M> InstIterator(M &m, bool)
67 : BBs(&m.getBasicBlockList()), BB(BBs->end()) { // end ctor
68 }
69
70 // Accessors to get at the underlying iterators...
getBasicBlockIterator()71 inline BBIty &getBasicBlockIterator() { return BB; }
getInstructionIterator()72 inline BIty &getInstructionIterator() { return BI; }
73
74 inline reference operator*() const { return *BI; }
75 inline pointer operator->() const { return &operator*(); }
76
77 inline bool operator==(const InstIterator &y) const {
78 return BB == y.BB && (BB == BBs->end() || BI == y.BI);
79 }
80 inline bool operator!=(const InstIterator& y) const {
81 return !operator==(y);
82 }
83
84 InstIterator& operator++() {
85 ++BI;
86 advanceToNextBB();
87 return *this;
88 }
89 inline InstIterator operator++(int) {
90 InstIterator tmp = *this; ++*this; return tmp;
91 }
92
93 InstIterator& operator--() {
94 while (BB == BBs->end() || BI == BB->begin()) {
95 --BB;
96 BI = BB->end();
97 }
98 --BI;
99 return *this;
100 }
101 inline InstIterator operator--(int) {
102 InstIterator tmp = *this; --*this; return tmp;
103 }
104
atEnd()105 inline bool atEnd() const { return BB == BBs->end(); }
106
107 private:
advanceToNextBB()108 inline void advanceToNextBB() {
109 // The only way that the II could be broken is if it is now pointing to
110 // the end() of the current BasicBlock and there are successor BBs.
111 while (BI == BB->end()) {
112 ++BB;
113 if (BB == BBs->end()) break;
114 BI = BB->begin();
115 }
116 }
117 };
118
119
120 typedef InstIterator<iplist<BasicBlock>,
121 Function::iterator, BasicBlock::iterator,
122 Instruction> inst_iterator;
123 typedef InstIterator<const iplist<BasicBlock>,
124 Function::const_iterator,
125 BasicBlock::const_iterator,
126 const Instruction> const_inst_iterator;
127
inst_begin(Function * F)128 inline inst_iterator inst_begin(Function *F) { return inst_iterator(*F); }
inst_end(Function * F)129 inline inst_iterator inst_end(Function *F) { return inst_iterator(*F, true); }
inst_begin(const Function * F)130 inline const_inst_iterator inst_begin(const Function *F) {
131 return const_inst_iterator(*F);
132 }
inst_end(const Function * F)133 inline const_inst_iterator inst_end(const Function *F) {
134 return const_inst_iterator(*F, true);
135 }
inst_begin(Function & F)136 inline inst_iterator inst_begin(Function &F) { return inst_iterator(F); }
inst_end(Function & F)137 inline inst_iterator inst_end(Function &F) { return inst_iterator(F, true); }
inst_begin(const Function & F)138 inline const_inst_iterator inst_begin(const Function &F) {
139 return const_inst_iterator(F);
140 }
inst_end(const Function & F)141 inline const_inst_iterator inst_end(const Function &F) {
142 return const_inst_iterator(F, true);
143 }
144
145 } // End llvm namespace
146
147 #endif
148