//===-- llvm/BasicBlock.h - Represent a basic block in the VM ----*- C++ -*--=//
-//
-// This file contains the declaration of the BasicBlock class, which represents
-// a single basic block in the VM.
-//
-// Note that basic blocks themselves are Def's, because they are referenced
-// by instructions like branches and can go in switch tables and stuff...
-//
-// This may see wierd at first, but it's really pretty cool. :)
-//
-//===----------------------------------------------------------------------===//
-//
-// Note that well formed basic blocks are formed of a list of instructions
-// followed by a single TerminatorInst instruction. TerminatorInst's may not
-// occur in the middle of basic blocks, and must terminate the blocks.
-//
-// This code allows malformed basic blocks to occur, because it may be useful
-// in the intermediate stage of analysis or modification of a program.
-//
+///
+/// \class BasicBlock
+///
+/// This file contains the declaration of the BasicBlock class, which represents
+/// a single basic block in the VM.
+///
+/// Note that basic blocks themselves are Value's, because they are referenced
+/// by instructions like branches and can go in switch tables and stuff...
+///
+///===---------------------------------------------------------------------===//
+///
+/// Note that well formed basic blocks are formed of a list of instructions
+/// followed by a single TerminatorInst instruction. TerminatorInst's may not
+/// occur in the middle of basic blocks, and must terminate the blocks.
+///
+/// This code allows malformed basic blocks to occur, because it may be useful
+/// in the intermediate stage modification to a program.
+///
//===----------------------------------------------------------------------===//
#ifndef LLVM_BASICBLOCK_H
#define LLVM_BASICBLOCK_H
-#include "llvm/Value.h" // Get the definition of Value
-#include "llvm/ValueHolder.h"
-#include "llvm/InstrTypes.h"
-#include <list>
+#include "llvm/Instruction.h"
+#include "llvm/SymbolTableListTraits.h"
+#include "Support/ilist"
-class Instruction;
-class Method;
-class BasicBlock;
class TerminatorInst;
-
-typedef UseTy<BasicBlock> BasicBlockUse;
+template <class _Term, class _BB> class SuccIterator; // Successor Iterator
+template <class _Ptr, class _USE_iterator> class PredIterator;
+
+template<> struct ilist_traits<Instruction>
+ : public SymbolTableListTraits<Instruction, BasicBlock, Function> {
+ // createNode is used to create a node that marks the end of the list...
+ static Instruction *createNode();
+ static iplist<Instruction> &getList(BasicBlock *BB);
+};
class BasicBlock : public Value { // Basic blocks are data objects also
public:
- typedef ValueHolder<Instruction, BasicBlock> InstListType;
+ typedef iplist<Instruction> InstListType;
private :
InstListType InstList;
+ BasicBlock *Prev, *Next; // Next and Prev links for our intrusive linked list
+
+ void setParent(Function *parent);
+ void setNext(BasicBlock *N) { Next = N; }
+ void setPrev(BasicBlock *N) { Prev = N; }
+ friend class SymbolTableListTraits<BasicBlock, Function, Function>;
- friend class ValueHolder<BasicBlock,Method>;
- void setParent(Method *parent);
+ BasicBlock(const BasicBlock &); // Do not implement
+ void operator=(const BasicBlock &); // Do not implement
public:
- BasicBlock(const string &Name = "", Method *Parent = 0);
+ /// Instruction iterators...
+ typedef InstListType::iterator iterator;
+ typedef InstListType::const_iterator const_iterator;
+ typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+ typedef std::reverse_iterator<iterator> reverse_iterator;
+
+ /// BasicBlock ctor - If the function parameter is specified, the basic block
+ /// is automatically inserted at the end of the function.
+ ///
+ BasicBlock(const std::string &Name = "", Function *Parent = 0);
~BasicBlock();
// Specialize setName to take care of symbol table majik
- virtual void setName(const string &name);
-
- const Method *getParent() const { return (const Method*)InstList.getParent();}
- Method *getParent() { return (Method*)InstList.getParent(); }
-
- const InstListType &getInstList() const { return InstList; }
- InstListType &getInstList() { return InstList; }
-
- // getTerminator() - If this is a well formed basic block, then this returns
- // a pointer to the terminator instruction. If it is not, then you get a null
- // pointer back.
- //
+ virtual void setName(const std::string &name, SymbolTable *ST = 0);
+
+ /// getParent - Return the enclosing method, or null if none
+ ///
+ const Function *getParent() const { return InstList.getParent(); }
+ Function *getParent() { return InstList.getParent(); }
+
+ // getNext/Prev - Return the next or previous basic block in the list.
+ BasicBlock *getNext() { return Next; }
+ const BasicBlock *getNext() const { return Next; }
+ BasicBlock *getPrev() { return Prev; }
+ const BasicBlock *getPrev() const { return Prev; }
+
+ /// getTerminator() - If this is a well formed basic block, then this returns
+ /// a pointer to the terminator instruction. If it is not, then you get a
+ /// null pointer back.
+ ///
TerminatorInst *getTerminator();
const TerminatorInst *const getTerminator() const;
-
- // hasConstantPoolReferences() - This predicate is true if there is a
- // reference to this basic block in the constant pool for this method. For
- // example, if a block is reached through a switch table, that table resides
- // in the constant pool, and the basic block is reference from it.
- //
- bool hasConstantPoolReferences() const;
-
- // dropAllReferences() - This function causes all the subinstructions to "let
- // go" of all references that they are maintaining. This allows one to
- // 'delete' a whole class at a time, even though there may be circular
- // references... first all references are dropped, and all use counts go to
- // zero. Then everything is delete'd for real. Note that no operations are
- // valid on an object that has "dropped all references", except operator
- // delete.
- //
- void dropAllReferences();
-
- // splitBasicBlock - This splits a basic block into two at the specified
- // instruction. Note that all instructions BEFORE the specified iterator stay
- // as part of the original basic block, an unconditional branch is added to
- // the new BB, and the rest of the instructions in the BB are moved to the new
- // BB, including the old terminator. The newly formed BasicBlock is returned.
- // This function invalidates the specified iterator.
- //
- // Note that this only works on well formed basic blocks (must have a
- // terminator), and 'I' must not be the end of instruction list (which would
- // cause a degenerate basic block to be formed, having a terminator inside of
- // the basic block).
- //
- BasicBlock *splitBasicBlock(InstListType::iterator I);
-
- //===--------------------------------------------------------------------===//
- // Predecessor iterator code
+
+ // Provide a scoped predecessor and successor iterator
+ typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
+ typedef PredIterator<const BasicBlock,
+ Value::use_const_iterator> pred_const_iterator;
+
+ typedef SuccIterator<TerminatorInst*, BasicBlock> succ_iterator;
+ typedef SuccIterator<const TerminatorInst*,
+ const BasicBlock> succ_const_iterator;
+
+
//===--------------------------------------------------------------------===//
- //
- // This is used to figure out what basic blocks we could be coming from.
- //
-
- // Forward declare iterator class template...
- template <class _Ptr, class _USE_iterator> class PredIterator;
-
- typedef PredIterator<BasicBlock*, use_iterator> pred_iterator;
- typedef PredIterator<const BasicBlock*,
- use_const_iterator> pred_const_iterator;
-
- inline pred_iterator pred_begin() ;
- inline pred_const_iterator pred_begin() const;
- inline pred_iterator pred_end() ;
- inline pred_const_iterator pred_end() const;
-
- //===--------------------------------------------------------------------===//
- // Successor iterator code
- //===--------------------------------------------------------------------===//
- //
- // This is used to figure out what basic blocks we could be going to...
- //
-
- // Forward declare iterator class template...
- template <class _Term, class _BB> class SuccIterator;
-
- typedef SuccIterator<TerminatorInst*, BasicBlock*> succ_iterator;
- typedef SuccIterator<const TerminatorInst*,
- const BasicBlock*> succ_const_iterator;
+ /// Instruction iterator methods
+ ///
+ inline iterator begin() { return InstList.begin(); }
+ inline const_iterator begin() const { return InstList.begin(); }
+ inline iterator end () { return InstList.end(); }
+ inline const_iterator end () const { return InstList.end(); }
+
+ inline reverse_iterator rbegin() { return InstList.rbegin(); }
+ inline const_reverse_iterator rbegin() const { return InstList.rbegin(); }
+ inline reverse_iterator rend () { return InstList.rend(); }
+ inline const_reverse_iterator rend () const { return InstList.rend(); }
+
+ inline unsigned size() const { return InstList.size(); }
+ inline bool empty() const { return InstList.empty(); }
+ inline const Instruction &front() const { return InstList.front(); }
+ inline Instruction &front() { return InstList.front(); }
+ inline const Instruction &back() const { return InstList.back(); }
+ inline Instruction &back() { return InstList.back(); }
+
+ /// getInstList() - Return the underlying instruction list container. You
+ /// need to access it directly if you want to modify it currently.
+ ///
+ const InstListType &getInstList() const { return InstList; }
+ InstListType &getInstList() { return InstList; }
- inline succ_iterator succ_begin() ;
- inline succ_const_iterator succ_begin() const;
- inline succ_iterator succ_end() ;
- inline succ_const_iterator succ_end() const;
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const BasicBlock *BB) { return true; }
+ static inline bool classof(const Value *V) {
+ return V->getValueType() == Value::BasicBlockVal;
+ }
+
+ /// hasConstantReferences() - This predicate is true if there is a
+ /// reference to this basic block in the constant pool for this method. For
+ /// example, if a block is reached through a switch table, that table resides
+ /// in the constant pool, and the basic block is reference from it.
+ ///
+ bool hasConstantReferences() const;
+
+ /// dropAllReferences() - This function causes all the subinstructions to "let
+ /// go" of all references that they are maintaining. This allows one to
+ /// 'delete' a whole class at a time, even though there may be circular
+ /// references... first all references are dropped, and all use counts go to
+ /// zero. Then everything is delete'd for real. Note that no operations are
+ /// valid on an object that has "dropped all references", except operator
+ /// delete.
+ ///
+ void dropAllReferences();
- //===--------------------------------------------------------------------===//
- // END of interesting code...
- //===--------------------------------------------------------------------===//
- //
- // Thank god C++ compilers are good at stomping out tons of templated code...
- //
- template <class _Ptr, class _USE_iterator> // Predecessor Iterator
- class PredIterator {
- const _Ptr ThisBB;
- _USE_iterator It;
- public:
- typedef PredIterator<_Ptr,_USE_iterator> _Self;
-
- typedef bidirectional_iterator_tag iterator_category;
- typedef _Ptr pointer;
-
- inline void advancePastConstPool() {
- // Loop to ignore constant pool references
- while (It != ThisBB->use_end() &&
- ((*It)->getValueType() != Value::InstructionVal))
- ++It;
- }
-
- inline PredIterator(_Ptr BB) : ThisBB(BB), It(BB->use_begin()) {
- advancePastConstPool();
- }
- inline PredIterator(_Ptr BB, bool) : ThisBB(BB), It(BB->use_end()) {}
-
- inline bool operator==(const _Self& x) const { return It == x.It; }
- inline bool operator!=(const _Self& x) const { return !operator==(x); }
-
- inline pointer operator*() const {
- assert ((*It)->getValueType() == Value::InstructionVal);
- return ((Instruction *)(*It))->getParent();
- }
- inline pointer *operator->() const { return &(operator*()); }
-
- inline _Self& operator++() { // Preincrement
- ++It; advancePastConstPool();
- return *this;
- }
-
- inline _Self operator++(int) { // Postincrement
- _Self tmp = *this; ++*this; return tmp;
- }
-
- inline _Self& operator--() { --It; return *this; } // Predecrement
- inline _Self operator--(int) { // Postdecrement
- _Self tmp = *this; --*this; return tmp;
- }
- };
-
- template <class _Term, class _BB> // Successor Iterator
- class SuccIterator {
- const _Term Term;
- unsigned idx;
- public:
- typedef SuccIterator<_Term, _BB> _Self;
- typedef forward_iterator_tag iterator_category;
- typedef _BB pointer;
-
- inline SuccIterator(_Term T) : Term(T), idx(0) {} // begin iterator
- inline SuccIterator(_Term T, bool)
- : Term(T), idx(Term->getNumSuccessors()) {} // end iterator
-
- inline bool operator==(const _Self& x) const { return idx == x.idx; }
- inline bool operator!=(const _Self& x) const { return !operator==(x); }
-
- inline pointer operator*() const { return Term->getSuccessor(idx); }
- inline pointer *operator->() const { return &(operator*()); }
-
- inline _Self& operator++() { ++idx; return *this; } // Preincrement
- inline _Self operator++(int) { // Postincrement
- _Self tmp = *this; ++*this; return tmp;
- }
-
- inline _Self& operator--() { --idx; return *this; } // Predecrement
- inline _Self operator--(int) { // Postdecrement
- _Self tmp = *this; --*this; return tmp;
- }
- };
+ /// removePredecessor - This method is used to notify a BasicBlock that the
+ /// specified Predecessor of the block is no longer able to reach it. This is
+ /// actually not used to update the Predecessor list, but is actually used to
+ /// update the PHI nodes that reside in the block. Note that this should be
+ /// called while the predecessor still refers to this block.
+ ///
+ void removePredecessor(BasicBlock *Pred);
+
+ /// splitBasicBlock - This splits a basic block into two at the specified
+ /// instruction. Note that all instructions BEFORE the specified iterator
+ /// stay as part of the original basic block, an unconditional branch is added
+ /// to the new BB, and the rest of the instructions in the BB are moved to the
+ /// new BB, including the old terminator. The newly formed BasicBlock is
+ /// returned. This function invalidates the specified iterator.
+ ///
+ /// Note that this only works on well formed basic blocks (must have a
+ /// terminator), and 'I' must not be the end of instruction list (which would
+ /// cause a degenerate basic block to be formed, having a terminator inside of
+ /// the basic block).
+ ///
+ BasicBlock *splitBasicBlock(iterator I);
};
-
-//===--------------------------------------------------------------------===//
-// Implement some stuff prototyped above...
-//===--------------------------------------------------------------------===//
-
-inline BasicBlock::pred_iterator BasicBlock::pred_begin() {
- return pred_iterator(this);
-}
-inline BasicBlock::pred_const_iterator BasicBlock::pred_begin() const {
- return pred_const_iterator(this);
-}
-inline BasicBlock::pred_iterator BasicBlock::pred_end() {
- return pred_iterator(this,true);
-}
-inline BasicBlock::pred_const_iterator BasicBlock::pred_end() const {
- return pred_const_iterator(this,true);
-}
-
-inline BasicBlock::succ_iterator BasicBlock::succ_begin() {
- return succ_iterator(getTerminator());
-}
-inline BasicBlock::succ_const_iterator BasicBlock::succ_begin() const {
- return succ_const_iterator(getTerminator());
-}
-inline BasicBlock::succ_iterator BasicBlock::succ_end() {
- return succ_iterator(getTerminator(),true);
-}
-inline BasicBlock::succ_const_iterator BasicBlock::succ_end() const {
- return succ_const_iterator(getTerminator(),true);
-}
-
#endif