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/ADT/iterator_range.h"
23#include "llvm/IR/BasicBlock.h"
24#include "llvm/IR/Function.h"
25#include "llvm/IR/SymbolTableListTraits.h"
26#include <iterator>
27
28namespace llvm {
29
30// This class implements inst_begin() & inst_end() for
31// inst_iterator and const_inst_iterator's.
32//
33template <class BB_t, class BB_i_t, class BI_t, class II_t> class InstIterator {
34 using BBty = BB_t;
35 using BBIty = BB_i_t;
36 using BIty = BI_t;
37 using IIty = II_t;
38 BB_t *BBs; // BasicBlocksType
39 BB_i_t BB; // BasicBlocksType::iterator
40 BI_t BI; // BasicBlock::iterator
41
42public:
43 using iterator_category = std::bidirectional_iterator_tag;
44 using value_type = IIty;
45 using difference_type = signed;
46 using pointer = IIty *;
47 using reference = IIty &;
48
49 // Default constructor
50 InstIterator() = default;
51
52 // Copy constructor...
53 template<typename A, typename B, typename C, typename D>
54 InstIterator(const InstIterator<A,B,C,D> &II)
55 : BBs(II.BBs), BB(II.BB), BI(II.BI) {}
56
57 template<typename A, typename B, typename C, typename D>
58 InstIterator(InstIterator<A,B,C,D> &II)
59 : BBs(II.BBs), BB(II.BB), BI(II.BI) {}
60
61 template<class M> InstIterator(M &m)
62 : BBs(&m.getBasicBlockList()), BB(BBs->begin()) { // begin ctor
63 if (BB != BBs->end()) {
64 BI = BB->begin();
65 advanceToNextBB();
66 }
67 }
68
69 template<class M> InstIterator(M &m, bool)
70 : BBs(&m.getBasicBlockList()), BB(BBs->end()) { // end ctor
71 }
72
73 // Accessors to get at the underlying iterators...
74 inline BBIty &getBasicBlockIterator() { return BB; }
75 inline BIty &getInstructionIterator() { return BI; }
76
77 inline reference operator*() const { return *BI; }
78 inline pointer operator->() const { return &operator*(); }
79
80 inline bool operator==(const InstIterator &y) const {
81 return BB == y.BB && (BB == BBs->end() || BI == y.BI);
82 }
83 inline bool operator!=(const InstIterator& y) const {
84 return !operator==(y);
85 }
86
87 InstIterator& operator++() {
88 ++BI;
89 advanceToNextBB();
90 return *this;
91 }
92 inline InstIterator operator++(int) {
93 InstIterator tmp = *this; ++*this; return tmp;
94 }
95
96 InstIterator& operator--() {
97 while (BB == BBs->end() || BI == BB->begin()) {
98 --BB;
99 BI = BB->end();
100 }
101 --BI;
102 return *this;
103 }
104 inline InstIterator operator--(int) {
105 InstIterator tmp = *this; --*this; return tmp;
106 }
107
108 inline bool atEnd() const { return BB == BBs->end(); }
109
110private:
111 inline void advanceToNextBB() {
112 // The only way that the II could be broken is if it is now pointing to
113 // the end() of the current BasicBlock and there are successor BBs.
114 while (BI == BB->end()) {
115 ++BB;
116 if (BB == BBs->end()) break;
117 BI = BB->begin();
118 }
119 }
120};
121
122using inst_iterator =
123 InstIterator<SymbolTableList<BasicBlock>, Function::iterator,
124 BasicBlock::iterator, Instruction>;
125using const_inst_iterator =
126 InstIterator<const SymbolTableList<BasicBlock>,
127 Function::const_iterator, BasicBlock::const_iterator,
128 const Instruction>;
129using inst_range = iterator_range<inst_iterator>;
130using const_inst_range = iterator_range<const_inst_iterator>;
131
132inline inst_iterator inst_begin(Function *F) { return inst_iterator(*F); }
133inline inst_iterator inst_end(Function *F) { return inst_iterator(*F, true); }
134inline inst_range instructions(Function *F) {
135 return inst_range(inst_begin(F), inst_end(F));
136}
137inline const_inst_iterator inst_begin(const Function *F) {
138 return const_inst_iterator(*F);
139}
140inline const_inst_iterator inst_end(const Function *F) {
141 return const_inst_iterator(*F, true);
142}
143inline const_inst_range instructions(const Function *F) {
144 return const_inst_range(inst_begin(F), inst_end(F));
145}
146inline inst_iterator inst_begin(Function &F) { return inst_iterator(F); }
147inline inst_iterator inst_end(Function &F) { return inst_iterator(F, true); }
148inline inst_range instructions(Function &F) {
149 return inst_range(inst_begin(F), inst_end(F));
150}
151inline const_inst_iterator inst_begin(const Function &F) {
152 return const_inst_iterator(F);
153}
154inline const_inst_iterator inst_end(const Function &F) {
155 return const_inst_iterator(F, true);
156}
157inline const_inst_range instructions(const Function &F) {
158 return const_inst_range(inst_begin(F), inst_end(F));
159}
160
161} // end namespace llvm
162
163#endif // LLVM_IR_INSTITERATOR_H
164