1 //===-- llvm/Support/CFG.h - Process LLVM structures as graphs ---*- C++ -*--=//
3 // This file defines specializations of GraphTraits that allow Function and
4 // BasicBlock graphs to be treated as proper graphs for generic algorithms.
6 //===----------------------------------------------------------------------===//
11 #include "Support/GraphTraits.h"
12 #include "llvm/Function.h"
13 #include "llvm/InstrTypes.h"
14 #include "Support/iterator"
16 //===--------------------------------------------------------------------===//
17 // BasicBlock pred_iterator definition
18 //===--------------------------------------------------------------------===//
20 template <class _Ptr, class _USE_iterator> // Predecessor Iterator
21 class PredIterator : public bidirectional_iterator<_Ptr, ptrdiff_t> {
22 typedef bidirectional_iterator<_Ptr, ptrdiff_t> super;
26 typedef PredIterator<_Ptr,_USE_iterator> _Self;
27 typedef typename super::pointer pointer;
29 inline PredIterator(_Ptr *bb) : BB(bb), It(bb->use_begin()) {
31 inline PredIterator(_Ptr *bb, bool) : BB(bb), It(bb->use_end()) {}
33 inline bool operator==(const _Self& x) const { return It == x.It; }
34 inline bool operator!=(const _Self& x) const { return !operator==(x); }
36 inline pointer operator*() const {
37 assert(It != BB->use_end() && "pred_iterator out of range!");
38 return cast<TerminatorInst>(*It)->getParent();
40 inline pointer *operator->() const { return &(operator*()); }
42 inline _Self& operator++() { // Preincrement
43 assert(It != BB->use_end() && "pred_iterator out of range!");
48 inline _Self operator++(int) { // Postincrement
49 _Self tmp = *this; ++*this; return tmp;
52 inline _Self& operator--() { --It; return *this; } // Predecrement
53 inline _Self operator--(int) { // Postdecrement
54 _Self tmp = *this; --*this; return tmp;
58 typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
59 typedef PredIterator<const BasicBlock,
60 Value::use_const_iterator> pred_const_iterator;
62 inline pred_iterator pred_begin(BasicBlock *BB) { return pred_iterator(BB); }
63 inline pred_const_iterator pred_begin(const BasicBlock *BB) {
64 return pred_const_iterator(BB);
66 inline pred_iterator pred_end(BasicBlock *BB) { return pred_iterator(BB, true);}
67 inline pred_const_iterator pred_end(const BasicBlock *BB) {
68 return pred_const_iterator(BB, true);
73 //===--------------------------------------------------------------------===//
74 // BasicBlock succ_iterator definition
75 //===--------------------------------------------------------------------===//
77 template <class _Term, class _BB> // Successor Iterator
78 class SuccIterator : public bidirectional_iterator<_BB, ptrdiff_t> {
81 typedef bidirectional_iterator<_BB, ptrdiff_t> super;
83 typedef SuccIterator<_Term, _BB> _Self;
84 typedef typename super::pointer pointer;
85 // TODO: This can be random access iterator, need operator+ and stuff tho
87 inline SuccIterator(_Term T) : Term(T), idx(0) { // begin iterator
88 assert(T && "getTerminator returned null!");
90 inline SuccIterator(_Term T, bool) // end iterator
91 : Term(T), idx(Term->getNumSuccessors()) {
92 assert(T && "getTerminator returned null!");
95 inline const _Self &operator=(const _Self &I) {
96 assert(Term == I.Term &&"Cannot assign iterators to two different blocks!");
101 inline bool operator==(const _Self& x) const { return idx == x.idx; }
102 inline bool operator!=(const _Self& x) const { return !operator==(x); }
104 inline pointer operator*() const { return Term->getSuccessor(idx); }
105 inline pointer operator->() const { return operator*(); }
107 inline _Self& operator++() { ++idx; return *this; } // Preincrement
108 inline _Self operator++(int) { // Postincrement
109 _Self tmp = *this; ++*this; return tmp;
112 inline _Self& operator--() { --idx; return *this; } // Predecrement
113 inline _Self operator--(int) { // Postdecrement
114 _Self tmp = *this; --*this; return tmp;
118 typedef SuccIterator<TerminatorInst*, BasicBlock> succ_iterator;
119 typedef SuccIterator<const TerminatorInst*,
120 const BasicBlock> succ_const_iterator;
122 inline succ_iterator succ_begin(BasicBlock *BB) {
123 return succ_iterator(BB->getTerminator());
125 inline succ_const_iterator succ_begin(const BasicBlock *BB) {
126 return succ_const_iterator(BB->getTerminator());
128 inline succ_iterator succ_end(BasicBlock *BB) {
129 return succ_iterator(BB->getTerminator(), true);
131 inline succ_const_iterator succ_end(const BasicBlock *BB) {
132 return succ_const_iterator(BB->getTerminator(), true);
137 //===--------------------------------------------------------------------===//
138 // GraphTraits specializations for basic block graphs (CFGs)
139 //===--------------------------------------------------------------------===//
141 // Provide specializations of GraphTraits to be able to treat a function as a
142 // graph of basic blocks...
144 template <> struct GraphTraits<BasicBlock*> {
145 typedef BasicBlock NodeType;
146 typedef succ_iterator ChildIteratorType;
148 static NodeType *getEntryNode(BasicBlock *BB) { return BB; }
149 static inline ChildIteratorType child_begin(NodeType *N) {
150 return succ_begin(N);
152 static inline ChildIteratorType child_end(NodeType *N) {
157 template <> struct GraphTraits<const BasicBlock*> {
158 typedef const BasicBlock NodeType;
159 typedef succ_const_iterator ChildIteratorType;
161 static NodeType *getEntryNode(const BasicBlock *BB) { return BB; }
163 static inline ChildIteratorType child_begin(NodeType *N) {
164 return succ_begin(N);
166 static inline ChildIteratorType child_end(NodeType *N) {
171 // Provide specializations of GraphTraits to be able to treat a function as a
172 // graph of basic blocks... and to walk it in inverse order. Inverse order for
173 // a function is considered to be when traversing the predecessor edges of a BB
174 // instead of the successor edges.
176 template <> struct GraphTraits<Inverse<BasicBlock*> > {
177 typedef BasicBlock NodeType;
178 typedef pred_iterator ChildIteratorType;
179 static NodeType *getEntryNode(Inverse<BasicBlock *> G) { return G.Graph; }
180 static inline ChildIteratorType child_begin(NodeType *N) {
181 return pred_begin(N);
183 static inline ChildIteratorType child_end(NodeType *N) {
188 template <> struct GraphTraits<Inverse<const BasicBlock*> > {
189 typedef const BasicBlock NodeType;
190 typedef pred_const_iterator ChildIteratorType;
191 static NodeType *getEntryNode(Inverse<const BasicBlock*> G) {
194 static inline ChildIteratorType child_begin(NodeType *N) {
195 return pred_begin(N);
197 static inline ChildIteratorType child_end(NodeType *N) {
204 //===--------------------------------------------------------------------===//
205 // GraphTraits specializations for function basic block graphs (CFGs)
206 //===--------------------------------------------------------------------===//
208 // Provide specializations of GraphTraits to be able to treat a function as a
209 // graph of basic blocks... these are the same as the basic block iterators,
210 // except that the root node is implicitly the first node of the function.
212 template <> struct GraphTraits<Function*> : public GraphTraits<BasicBlock*> {
213 static NodeType *getEntryNode(Function *F) { return &F->getEntryNode(); }
215 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
216 typedef Function::iterator nodes_iterator;
217 static nodes_iterator nodes_begin(Function *F) { return F->begin(); }
218 static nodes_iterator nodes_end (Function *F) { return F->end(); }
220 template <> struct GraphTraits<const Function*> :
221 public GraphTraits<const BasicBlock*> {
222 static NodeType *getEntryNode(const Function *F) { return &F->getEntryNode();}
224 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
225 typedef Function::const_iterator nodes_iterator;
226 static nodes_iterator nodes_begin(const Function *F) { return F->begin(); }
227 static nodes_iterator nodes_end (const Function *F) { return F->end(); }
231 // Provide specializations of GraphTraits to be able to treat a function as a
232 // graph of basic blocks... and to walk it in inverse order. Inverse order for
233 // a function is considered to be when traversing the predecessor edges of a BB
234 // instead of the successor edges.
236 template <> struct GraphTraits<Inverse<Function*> > :
237 public GraphTraits<Inverse<BasicBlock*> > {
238 static NodeType *getEntryNode(Inverse<Function*> G) {
239 return &G.Graph->getEntryNode();
242 template <> struct GraphTraits<Inverse<const Function*> > :
243 public GraphTraits<Inverse<const BasicBlock*> > {
244 static NodeType *getEntryNode(Inverse<const Function *> G) {
245 return &G.Graph->getEntryNode();