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"
18 //===--------------------------------------------------------------------===//
19 // BasicBlock pred_iterator definition
20 //===--------------------------------------------------------------------===//
22 template <class _Ptr, class _USE_iterator> // Predecessor Iterator
23 class PredIterator : public bidirectional_iterator<_Ptr, ptrdiff_t> {
24 typedef bidirectional_iterator<_Ptr, ptrdiff_t> super;
28 typedef PredIterator<_Ptr,_USE_iterator> _Self;
29 typedef typename super::pointer pointer;
31 inline void advancePastConstants() {
32 // Loop to ignore non terminator uses (for example PHI nodes)...
33 while (It != BB->use_end() && !isa<TerminatorInst>(*It))
37 inline PredIterator(_Ptr *bb) : BB(bb), It(bb->use_begin()) {
38 advancePastConstants();
40 inline PredIterator(_Ptr *bb, bool) : BB(bb), It(bb->use_end()) {}
42 inline bool operator==(const _Self& x) const { return It == x.It; }
43 inline bool operator!=(const _Self& x) const { return !operator==(x); }
45 inline pointer operator*() const {
46 assert(It != BB->use_end() && "pred_iterator out of range!");
47 return cast<TerminatorInst>(*It)->getParent();
49 inline pointer *operator->() const { return &(operator*()); }
51 inline _Self& operator++() { // Preincrement
52 assert(It != BB->use_end() && "pred_iterator out of range!");
53 ++It; advancePastConstants();
57 inline _Self operator++(int) { // Postincrement
58 _Self tmp = *this; ++*this; return tmp;
61 inline _Self& operator--() { --It; return *this; } // Predecrement
62 inline _Self operator--(int) { // Postdecrement
63 _Self tmp = *this; --*this; return tmp;
67 typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
68 typedef PredIterator<const BasicBlock,
69 Value::use_const_iterator> pred_const_iterator;
71 inline pred_iterator pred_begin(BasicBlock *BB) { return pred_iterator(BB); }
72 inline pred_const_iterator pred_begin(const BasicBlock *BB) {
73 return pred_const_iterator(BB);
75 inline pred_iterator pred_end(BasicBlock *BB) { return pred_iterator(BB, true);}
76 inline pred_const_iterator pred_end(const BasicBlock *BB) {
77 return pred_const_iterator(BB, true);
82 //===--------------------------------------------------------------------===//
83 // BasicBlock succ_iterator definition
84 //===--------------------------------------------------------------------===//
86 template <class _Term, class _BB> // Successor Iterator
87 class SuccIterator : public bidirectional_iterator<_BB, ptrdiff_t> {
90 typedef bidirectional_iterator<_BB, ptrdiff_t> super;
92 typedef SuccIterator<_Term, _BB> _Self;
93 typedef typename super::pointer pointer;
94 // TODO: This can be random access iterator, need operator+ and stuff tho
96 inline SuccIterator(_Term T) : Term(T), idx(0) { // begin iterator
97 assert(T && "getTerminator returned null!");
99 inline SuccIterator(_Term T, bool) // end iterator
100 : Term(T), idx(Term->getNumSuccessors()) {
101 assert(T && "getTerminator returned null!");
104 inline const _Self &operator=(const _Self &I) {
105 assert(Term == I.Term &&"Cannot assign iterators to two different blocks!");
110 inline bool operator==(const _Self& x) const { return idx == x.idx; }
111 inline bool operator!=(const _Self& x) const { return !operator==(x); }
113 inline pointer operator*() const { return Term->getSuccessor(idx); }
114 inline pointer operator->() const { return operator*(); }
116 inline _Self& operator++() { ++idx; return *this; } // Preincrement
117 inline _Self operator++(int) { // Postincrement
118 _Self tmp = *this; ++*this; return tmp;
121 inline _Self& operator--() { --idx; return *this; } // Predecrement
122 inline _Self operator--(int) { // Postdecrement
123 _Self tmp = *this; --*this; return tmp;
127 typedef SuccIterator<TerminatorInst*, BasicBlock> succ_iterator;
128 typedef SuccIterator<const TerminatorInst*,
129 const BasicBlock> succ_const_iterator;
131 inline succ_iterator succ_begin(BasicBlock *BB) {
132 return succ_iterator(BB->getTerminator());
134 inline succ_const_iterator succ_begin(const BasicBlock *BB) {
135 return succ_const_iterator(BB->getTerminator());
137 inline succ_iterator succ_end(BasicBlock *BB) {
138 return succ_iterator(BB->getTerminator(), true);
140 inline succ_const_iterator succ_end(const BasicBlock *BB) {
141 return succ_const_iterator(BB->getTerminator(), true);
146 //===--------------------------------------------------------------------===//
147 // GraphTraits specializations for basic block graphs (CFGs)
148 //===--------------------------------------------------------------------===//
150 // Provide specializations of GraphTraits to be able to treat a function as a
151 // graph of basic blocks...
153 template <> struct GraphTraits<BasicBlock*> {
154 typedef BasicBlock NodeType;
155 typedef succ_iterator ChildIteratorType;
157 static NodeType *getEntryNode(BasicBlock *BB) { return BB; }
158 static inline ChildIteratorType child_begin(NodeType *N) {
159 return succ_begin(N);
161 static inline ChildIteratorType child_end(NodeType *N) {
166 template <> struct GraphTraits<const BasicBlock*> {
167 typedef const BasicBlock NodeType;
168 typedef succ_const_iterator ChildIteratorType;
170 static NodeType *getEntryNode(const BasicBlock *BB) { return BB; }
172 static inline ChildIteratorType child_begin(NodeType *N) {
173 return succ_begin(N);
175 static inline ChildIteratorType child_end(NodeType *N) {
180 // Provide specializations of GraphTraits to be able to treat a function as a
181 // graph of basic blocks... and to walk it in inverse order. Inverse order for
182 // a function is considered to be when traversing the predecessor edges of a BB
183 // instead of the successor edges.
185 template <> struct GraphTraits<Inverse<BasicBlock*> > {
186 typedef BasicBlock NodeType;
187 typedef pred_iterator ChildIteratorType;
188 static NodeType *getEntryNode(Inverse<BasicBlock *> G) { return G.Graph; }
189 static inline ChildIteratorType child_begin(NodeType *N) {
190 return pred_begin(N);
192 static inline ChildIteratorType child_end(NodeType *N) {
197 template <> struct GraphTraits<Inverse<const BasicBlock*> > {
198 typedef const BasicBlock NodeType;
199 typedef pred_const_iterator ChildIteratorType;
200 static NodeType *getEntryNode(Inverse<const BasicBlock*> G) {
203 static inline ChildIteratorType child_begin(NodeType *N) {
204 return pred_begin(N);
206 static inline ChildIteratorType child_end(NodeType *N) {
213 //===--------------------------------------------------------------------===//
214 // GraphTraits specializations for function basic block graphs (CFGs)
215 //===--------------------------------------------------------------------===//
217 // Provide specializations of GraphTraits to be able to treat a function as a
218 // graph of basic blocks... these are the same as the basic block iterators,
219 // except that the root node is implicitly the first node of the function.
221 template <> struct GraphTraits<Function*> : public GraphTraits<BasicBlock*> {
222 static NodeType *getEntryNode(Function *F) { return &F->getEntryNode(); }
224 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
225 typedef Function::iterator nodes_iterator;
226 static nodes_iterator nodes_begin(Function *F) { return F->begin(); }
227 static nodes_iterator nodes_end (Function *F) { return F->end(); }
229 template <> struct GraphTraits<const Function*> :
230 public GraphTraits<const BasicBlock*> {
231 static NodeType *getEntryNode(const Function *F) { return &F->getEntryNode();}
233 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
234 typedef Function::const_iterator nodes_iterator;
235 static nodes_iterator nodes_begin(const Function *F) { return F->begin(); }
236 static nodes_iterator nodes_end (const Function *F) { return F->end(); }
240 // Provide specializations of GraphTraits to be able to treat a function as a
241 // graph of basic blocks... and to walk it in inverse order. Inverse order for
242 // a function is considered to be when traversing the predecessor edges of a BB
243 // instead of the successor edges.
245 template <> struct GraphTraits<Inverse<Function*> > :
246 public GraphTraits<Inverse<BasicBlock*> > {
247 static NodeType *getEntryNode(Inverse<Function*> G) {
248 return &G.Graph->getEntryNode();
251 template <> struct GraphTraits<Inverse<const Function*> > :
252 public GraphTraits<Inverse<const BasicBlock*> > {
253 static NodeType *getEntryNode(Inverse<const Function *> G) {
254 return &G.Graph->getEntryNode();