X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FCFG.h;h=f5dc8ea055a37e064f4f0776714a2fe887f4ea9e;hb=cbeb8d9869aafec3c2c1ee0922f0a4d5bb4a916a;hp=1aa289178bc494b62ebfc560d955ac497db5369c;hpb=6193e5b128489c529176c038c76c11e549c4ee12;p=oota-llvm.git

diff --git a/include/llvm/Support/CFG.h b/include/llvm/Support/CFG.h
index 1aa289178bc..f5dc8ea055a 100644
--- a/include/llvm/Support/CFG.h
+++ b/include/llvm/Support/CFG.h
@@ -25,7 +25,7 @@ namespace llvm {
 // BasicBlock pred_iterator definition
 //===----------------------------------------------------------------------===//
 
-template <class Ptr,  class USE_iterator> // Predecessor Iterator
+template <class Ptr, class USE_iterator> // Predecessor Iterator
 class PredIterator : public std::iterator<std::forward_iterator_tag,
                                           Ptr, ptrdiff_t> {
   typedef std::iterator<std::forward_iterator_tag, Ptr, ptrdiff_t> super;
@@ -33,7 +33,7 @@ class PredIterator : public std::iterator<std::forward_iterator_tag,
   USE_iterator It;
 
   inline void advancePastNonTerminators() {
-    // Loop to ignore non terminator uses (for example PHI nodes)...
+    // Loop to ignore non terminator uses (for example BlockAddresses).
     while (!It.atEnd() && !isa<TerminatorInst>(*It))
       ++It;
   }
@@ -41,7 +41,8 @@ class PredIterator : public std::iterator<std::forward_iterator_tag,
 public:
   typedef typename super::pointer pointer;
 
-  inline PredIterator(Ptr *bb) : It(bb->use_begin()) {
+  PredIterator() {}
+  explicit inline PredIterator(Ptr *bb) : It(bb->use_begin()) {
     advancePastNonTerminators();
   }
   inline PredIterator(Ptr *bb, bool) : It(bb->use_end()) {}
@@ -53,7 +54,7 @@ public:
     assert(!It.atEnd() && "pred_iterator out of range!");
     return cast<TerminatorInst>(*It)->getParent();
   }
-  inline pointer *operator->() const { return &(operator*()); }
+  inline pointer *operator->() const { return &operator*(); }
 
   inline Self& operator++() {   // Preincrement
     assert(!It.atEnd() && "pred_iterator out of range!");
@@ -64,6 +65,18 @@ public:
   inline Self operator++(int) { // Postincrement
     Self tmp = *this; ++*this; return tmp;
   }
+
+  /// getOperandNo - Return the operand number in the predecessor's
+  /// terminator of the successor.
+  unsigned getOperandNo() const {
+    return It.getOperandNo();
+  }
+
+  /// getUse - Return the operand Use in the predecessor's terminator
+  /// of the successor.
+  Use &getUse() const {
+    return It.getUse();
+  }
 };
 
 typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
@@ -101,12 +114,19 @@ public:
   typedef typename super::pointer pointer;
   // TODO: This can be random access iterator, only operator[] missing.
 
-  inline SuccIterator(Term_ T) : Term(T), idx(0) {         // begin iterator
-    assert(T && "getTerminator returned null!");
+  explicit inline SuccIterator(Term_ T) : Term(T), idx(0) {// begin iterator
   }
   inline SuccIterator(Term_ T, bool)                       // end iterator
-    : Term(T), idx(Term->getNumSuccessors()) {
-    assert(T && "getTerminator returned null!");
+    : Term(T) {
+    if (Term)
+      idx = Term->getNumSuccessors();
+    else
+      // Term == NULL happens, if a basic block is not fully constructed and
+      // consequently getTerminator() returns NULL. In this case we construct a
+      // SuccIterator which describes a basic block that has zero successors.
+      // Defining SuccIterator for incomplete and malformed CFGs is especially
+      // useful for debugging.
+      idx = 0;
   }
 
   inline const Self &operator=(const Self &I) {
@@ -194,7 +214,8 @@ public:
 
   /// Get the source BB of this iterator.
   inline BB_ *getSource() {
-      return Term->getParent();
+    assert(Term && "Source not available, if basic block was malformed");
+    return Term->getParent();
   }
 };
 
@@ -299,6 +320,7 @@ template <> struct GraphTraits<Function*> : public GraphTraits<BasicBlock*> {
   typedef Function::iterator nodes_iterator;
   static nodes_iterator nodes_begin(Function *F) { return F->begin(); }
   static nodes_iterator nodes_end  (Function *F) { return F->end(); }
+  static unsigned       size       (Function *F) { return F->size(); }
 };
 template <> struct GraphTraits<const Function*> :
   public GraphTraits<const BasicBlock*> {
@@ -308,6 +330,7 @@ template <> struct GraphTraits<const Function*> :
   typedef Function::const_iterator nodes_iterator;
   static nodes_iterator nodes_begin(const Function *F) { return F->begin(); }
   static nodes_iterator nodes_end  (const Function *F) { return F->end(); }
+  static unsigned       size       (const Function *F) { return F->size(); }
 };