#include "llvm/Instruction.h"
#include "llvm/SymbolTableListTraits.h"
#include "llvm/ADT/ilist.h"
+#include "llvm/ADT/Twine.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
class TerminatorInst;
+class LLVMContext;
+class BlockAddress;
template<> struct ilist_traits<Instruction>
: public SymbolTableListTraits<Instruction, BasicBlock> {
Instruction *provideInitialHead() const { return createSentinel(); }
Instruction *ensureHead(Instruction*) const { return createSentinel(); }
static void noteHead(Instruction*, Instruction*) {}
-
- static ValueSymbolTable *getSymTab(BasicBlock *ItemParent);
private:
- mutable ilist_node<Instruction> Sentinel;
+ mutable ilist_half_node<Instruction> Sentinel;
};
/// This represents a single basic block in LLVM. A basic block is simply a
/// tables. The type of a BasicBlock is "Type::LabelTy" because the basic block
/// represents a label to which a branch can jump.
///
-/// A well formed basic block is formed of a list of non-terminating
-/// instructions followed by a single TerminatorInst instruction.
-/// TerminatorInst's may not occur in the middle of basic blocks, and must
+/// A well formed basic block is formed of a list of non-terminating
+/// instructions followed by a single TerminatorInst instruction.
+/// TerminatorInst's may not occur in the middle of basic blocks, and must
/// terminate the blocks. The BasicBlock class allows malformed basic blocks to
/// occur because it may be useful in the intermediate stage of constructing or
/// modifying a program. However, the verifier will ensure that basic blocks
/// @brief LLVM Basic Block Representation
class BasicBlock : public Value, // Basic blocks are data objects also
public ilist_node<BasicBlock> {
-
+ friend class BlockAddress;
public:
typedef iplist<Instruction> InstListType;
private:
/// is automatically inserted at either the end of the function (if
/// InsertBefore is null), or before the specified basic block.
///
- explicit BasicBlock(const std::string &Name = "", Function *Parent = 0,
- BasicBlock *InsertBefore = 0);
+ explicit BasicBlock(LLVMContext &C, const Twine &Name = "",
+ Function *Parent = 0, BasicBlock *InsertBefore = 0);
public:
+ /// getContext - Get the context in which this basic block lives.
+ LLVMContext &getContext() const;
+
/// Instruction iterators...
typedef InstListType::iterator iterator;
typedef InstListType::const_iterator const_iterator;
/// Create - Creates a new BasicBlock. If the Parent parameter is specified,
/// the basic block is automatically inserted at either the end of the
/// function (if InsertBefore is 0), or before the specified basic block.
- static BasicBlock *Create(const std::string &Name = "", Function *Parent = 0,
- BasicBlock *InsertBefore = 0) {
- return new BasicBlock(Name, Parent, InsertBefore);
+ static BasicBlock *Create(LLVMContext &Context, const Twine &Name = "",
+ Function *Parent = 0,BasicBlock *InsertBefore = 0) {
+ return new BasicBlock(Context, Name, Parent, InsertBefore);
}
~BasicBlock();
Function *getParent() { return Parent; }
/// use_back - Specialize the methods defined in Value, as we know that an
- /// BasicBlock can only be used by Instructions (specifically PHI nodes and
- /// terminators).
- Instruction *use_back() { return cast<Instruction>(*use_begin());}
- const Instruction *use_back() const { return cast<Instruction>(*use_begin());}
-
+ /// BasicBlock can only be used by Users (specifically terminators
+ /// and BlockAddress's).
+ User *use_back() { return cast<User>(*use_begin());}
+ const User *use_back() const { return cast<User>(*use_begin());}
+
/// 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 *getTerminator() const;
-
- /// Returns a pointer to the first instructon in this block that is not a
+
+ /// Returns a pointer to the first instructon in this block that is not a
/// PHINode instruction. When adding instruction to the beginning of the
/// basic block, they should be added before the returned value, not before
/// the first instruction, which might be PHI.
const Instruction* getFirstNonPHI() const {
return const_cast<BasicBlock*>(this)->getFirstNonPHI();
}
-
+
+ // Same as above, but also skip debug intrinsics.
+ Instruction* getFirstNonPHIOrDbg();
+ const Instruction* getFirstNonPHIOrDbg() const {
+ return const_cast<BasicBlock*>(this)->getFirstNonPHIOrDbg();
+ }
+
/// removeFromParent - This method unlinks 'this' from the containing
/// function, but does not delete it.
///
/// and deletes it.
///
void eraseFromParent();
-
+
/// moveBefore - Unlink this basic block from its current function and
/// insert it into the function that MovePos lives in, right before MovePos.
void moveBefore(BasicBlock *MovePos);
-
+
/// moveAfter - Unlink this basic block from its current function and
/// insert it into the function that MovePos lives in, right after MovePos.
void moveAfter(BasicBlock *MovePos);
-
+
/// getSinglePredecessor - If this basic block has a single predecessor block,
/// return the block, otherwise return a null pointer.
/// getUniquePredecessor - If this basic block has a unique predecessor block,
/// return the block, otherwise return a null pointer.
- /// Note that unique predecessor doesn't mean single edge, there can be
- /// multiple edges from the unique predecessor to this block (for example
+ /// Note that unique predecessor doesn't mean single edge, there can be
+ /// multiple edges from the unique predecessor to this block (for example
/// a switch statement with multiple cases having the same destination).
BasicBlock *getUniquePredecessor();
const BasicBlock *getUniquePredecessor() const {
///
const InstListType &getInstList() const { return InstList; }
InstListType &getInstList() { return InstList; }
+
+ /// getSublistAccess() - returns pointer to member of instruction list
static iplist<Instruction> BasicBlock::*getSublistAccess(Instruction*) {
return &BasicBlock::InstList;
}
+ /// getValueSymbolTable() - returns pointer to symbol table (if any)
+ ValueSymbolTable *getValueSymbolTable();
+
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const BasicBlock *) { return true; }
static inline bool classof(const Value *V) {
/// cause a degenerate basic block to be formed, having a terminator inside of
/// the basic block).
///
- BasicBlock *splitBasicBlock(iterator I, const std::string &BBName = "");
+ /// Also note that this doesn't preserve any passes. To split blocks while
+ /// keeping loop information consistent, use the SplitBlock utility function.
+ ///
+ BasicBlock *splitBasicBlock(iterator I, const Twine &BBName = "");
+
+ /// hasAddressTaken - returns true if there are any uses of this basic block
+ /// other than direct branches, switches, etc. to it.
+ bool hasAddressTaken() const { return getSubclassDataFromValue() != 0; }
+
+ /// replaceSuccessorsPhiUsesWith - Update all phi nodes in all our successors
+ /// to refer to basic block New instead of to us.
+ void replaceSuccessorsPhiUsesWith(BasicBlock *New);
+
+private:
+ /// AdjustBlockAddressRefCount - BasicBlock stores the number of BlockAddress
+ /// objects using it. This is almost always 0, sometimes one, possibly but
+ /// almost never 2, and inconceivably 3 or more.
+ void AdjustBlockAddressRefCount(int Amt) {
+ setValueSubclassData(getSubclassDataFromValue()+Amt);
+ assert((int)(signed char)getSubclassDataFromValue() >= 0 &&
+ "Refcount wrap-around");
+ }
+ // Shadow Value::setValueSubclassData with a private forwarding method so that
+ // any future subclasses cannot accidentally use it.
+ void setValueSubclassData(unsigned short D) {
+ Value::setValueSubclassData(D);
+ }
};
} // End llvm namespace
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