//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_BASICBLOCK_H
-#define LLVM_BASICBLOCK_H
+#ifndef LLVM_IR_BASICBLOCK_H
+#define LLVM_IR_BASICBLOCK_H
#include "llvm/ADT/Twine.h"
#include "llvm/ADT/ilist.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/SymbolTableListTraits.h"
+#include "llvm/Support/CBindingWrapping.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
+class CallInst;
class LandingPadInst;
class TerminatorInst;
class LLVMContext;
class BlockAddress;
+class Function;
-template<> struct ilist_traits<Instruction>
- : public SymbolTableListTraits<Instruction, BasicBlock> {
- // createSentinel is used to get hold of a node that marks the end of
- // the list...
- // The sentinel is relative to this instance, so we use a non-static
- // method.
- Instruction *createSentinel() const {
- // since i(p)lists always publicly derive from the corresponding
- // traits, placing a data member in this class will augment i(p)list.
- // But since the NodeTy is expected to publicly derive from
- // ilist_node<NodeTy>, there is a legal viable downcast from it
- // to NodeTy. We use this trick to superpose i(p)list with a "ghostly"
- // NodeTy, which becomes the sentinel. Dereferencing the sentinel is
- // forbidden (save the ilist_node<NodeTy>) so no one will ever notice
- // the superposition.
- return static_cast<Instruction*>(&Sentinel);
- }
- static void destroySentinel(Instruction*) {}
-
- Instruction *provideInitialHead() const { return createSentinel(); }
- Instruction *ensureHead(Instruction*) const { return createSentinel(); }
- static void noteHead(Instruction*, Instruction*) {}
-private:
- mutable ilist_half_node<Instruction> Sentinel;
-};
+template <>
+struct SymbolTableListSentinelTraits<BasicBlock>
+ : public ilist_half_embedded_sentinel_traits<BasicBlock> {};
+/// \brief LLVM Basic Block Representation
+///
/// This represents a single basic block in LLVM. A basic block is simply a
/// container of instructions that execute sequentially. Basic blocks are Values
/// because they are referenced by instructions such as branches and switch
/// occur because it may be useful in the intermediate stage of constructing or
/// modifying a program. However, the verifier will ensure that basic blocks
/// are "well formed".
-/// @brief LLVM Basic Block Representation
class BasicBlock : public Value, // Basic blocks are data objects also
- public ilist_node<BasicBlock> {
+ public ilist_node_with_parent<BasicBlock, Function> {
friend class BlockAddress;
public:
- typedef iplist<Instruction> InstListType;
+ typedef SymbolTableList<Instruction> InstListType;
+
private:
InstListType InstList;
Function *Parent;
void setParent(Function *parent);
- friend class SymbolTableListTraits<BasicBlock, Function>;
+ friend class SymbolTableListTraits<BasicBlock>;
- BasicBlock(const BasicBlock &) LLVM_DELETED_FUNCTION;
- void operator=(const BasicBlock &) LLVM_DELETED_FUNCTION;
+ BasicBlock(const BasicBlock &) = delete;
+ void operator=(const BasicBlock &) = delete;
- /// BasicBlock ctor - If the function parameter is specified, the basic block
- /// is automatically inserted at either the end of the function (if
- /// InsertBefore is null), or before the specified basic block.
+ /// \brief Constructor.
///
+ /// If the function parameter is specified, the basic block is automatically
+ /// inserted at either the end of the function (if InsertBefore is null), or
+ /// before the specified basic block.
explicit BasicBlock(LLVMContext &C, const Twine &Name = "",
- Function *Parent = 0, BasicBlock *InsertBefore = 0);
+ Function *Parent = nullptr,
+ BasicBlock *InsertBefore = nullptr);
public:
- /// getContext - Get the context in which this basic block lives.
+ /// \brief Get the context in which this basic block lives.
LLVMContext &getContext() const;
/// Instruction iterators...
typedef InstListType::reverse_iterator reverse_iterator;
typedef InstListType::const_reverse_iterator const_reverse_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.
+ /// \brief 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(LLVMContext &Context, const Twine &Name = "",
- Function *Parent = 0,BasicBlock *InsertBefore = 0) {
+ Function *Parent = nullptr,
+ BasicBlock *InsertBefore = nullptr) {
return new BasicBlock(Context, Name, Parent, InsertBefore);
}
- ~BasicBlock();
+ ~BasicBlock() override;
- /// getParent - Return the enclosing method, or null if none
- ///
+ /// \brief Return the enclosing method, or null if none.
const Function *getParent() const { return Parent; }
Function *getParent() { return Parent; }
- /// 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.
+ /// \brief Return the module owning the function this basic block belongs to,
+ /// or nullptr it the function does not have a module.
///
+ /// Note: this is undefined behavior if the block does not have a parent.
+ const Module *getModule() const;
+ Module *getModule();
+
+ /// \brief Returns the terminator instruction if the block is well formed or
+ /// null if the block is not well formed.
TerminatorInst *getTerminator();
const TerminatorInst *getTerminator() const;
- /// 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.
- /// Returns 0 is there's no non-PHI instruction.
+ /// \brief Returns the call instruction marked 'musttail' prior to the
+ /// terminating return instruction of this basic block, if such a call is
+ /// present. Otherwise, returns null.
+ CallInst *getTerminatingMustTailCall();
+ const CallInst *getTerminatingMustTailCall() const {
+ return const_cast<BasicBlock *>(this)->getTerminatingMustTailCall();
+ }
+
+ /// \brief Returns a pointer to the first instruction in this block that is
+ /// not a PHINode instruction.
+ ///
+ /// When adding instructions to the beginning of the basic block, they should
+ /// be added before the returned value, not before the first instruction,
+ /// which might be PHI. Returns 0 is there's no non-PHI instruction.
Instruction* getFirstNonPHI();
const Instruction* getFirstNonPHI() const {
return const_cast<BasicBlock*>(this)->getFirstNonPHI();
}
- // Same as above, but also skip debug intrinsics.
+ /// \brief Returns a pointer to the first instruction in this block that is not
+ /// a PHINode or a debug intrinsic.
Instruction* getFirstNonPHIOrDbg();
const Instruction* getFirstNonPHIOrDbg() const {
return const_cast<BasicBlock*>(this)->getFirstNonPHIOrDbg();
}
- // Same as above, but also skip lifetime intrinsics.
+ /// \brief Returns a pointer to the first instruction in this block that is not
+ /// a PHINode, a debug intrinsic, or a lifetime intrinsic.
Instruction* getFirstNonPHIOrDbgOrLifetime();
const Instruction* getFirstNonPHIOrDbgOrLifetime() const {
return const_cast<BasicBlock*>(this)->getFirstNonPHIOrDbgOrLifetime();
}
- /// getFirstInsertionPt - Returns an iterator to the first instruction in this
- /// block that is suitable for inserting a non-PHI instruction. In particular,
- /// it skips all PHIs and LandingPad instructions.
+ /// \brief Returns an iterator to the first instruction in this block that is
+ /// suitable for inserting a non-PHI instruction.
+ ///
+ /// In particular, it skips all PHIs and LandingPad instructions.
iterator getFirstInsertionPt();
const_iterator getFirstInsertionPt() const {
return const_cast<BasicBlock*>(this)->getFirstInsertionPt();
}
- /// removeFromParent - This method unlinks 'this' from the containing
- /// function, but does not delete it.
- ///
+ /// \brief Unlink 'this' from the containing function, but do not delete it.
void removeFromParent();
- /// eraseFromParent - This method unlinks 'this' from the containing function
- /// and deletes it.
+ /// \brief Unlink 'this' from the containing function and delete it.
///
- void eraseFromParent();
+ // \returns an iterator pointing to the element after the erased one.
+ SymbolTableList<BasicBlock>::iterator eraseFromParent();
- /// moveBefore - Unlink this basic block from its current function and
- /// insert it into the function that MovePos lives in, right before MovePos.
+ /// \brief Unlink this basic block from its current function and insert it
+ /// into the function that \p MovePos lives in, right before \p 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.
+ /// \brief Unlink this basic block from its current function and insert it
+ /// right after \p MovePos in the function \p MovePos lives in.
void moveAfter(BasicBlock *MovePos);
+ /// \brief Insert unlinked basic block into a function.
+ ///
+ /// Inserts an unlinked basic block into \c Parent. If \c InsertBefore is
+ /// provided, inserts before that basic block, otherwise inserts at the end.
+ ///
+ /// \pre \a getParent() is \c nullptr.
+ void insertInto(Function *Parent, BasicBlock *InsertBefore = nullptr);
- /// getSinglePredecessor - If this basic block has a single predecessor block,
- /// return the block, otherwise return a null pointer.
+ /// \brief Return the predecessor of this block if it has a single predecessor
+ /// block. Otherwise return a null pointer.
BasicBlock *getSinglePredecessor();
const BasicBlock *getSinglePredecessor() const {
return const_cast<BasicBlock*>(this)->getSinglePredecessor();
}
- /// getUniquePredecessor - If this basic block has a unique predecessor block,
- /// return the block, otherwise return a null pointer.
+ /// \brief Return the predecessor of this block if it has a unique predecessor
+ /// 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
- /// a switch statement with multiple cases having the same destination).
+ /// 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 {
return const_cast<BasicBlock*>(this)->getUniquePredecessor();
}
+ /// \brief Return the successor of this block if it has a single successor.
+ /// Otherwise return a null pointer.
+ ///
+ /// This method is analogous to getSinglePredecessor above.
+ BasicBlock *getSingleSuccessor();
+ const BasicBlock *getSingleSuccessor() const {
+ return const_cast<BasicBlock*>(this)->getSingleSuccessor();
+ }
+
+ /// \brief Return the successor of this block if it has a unique successor.
+ /// Otherwise return a null pointer.
+ ///
+ /// This method is analogous to getUniquePredecessor above.
+ BasicBlock *getUniqueSuccessor();
+ const BasicBlock *getUniqueSuccessor() const {
+ return const_cast<BasicBlock*>(this)->getUniqueSuccessor();
+ }
+
//===--------------------------------------------------------------------===//
/// Instruction iterator methods
///
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.
+ /// \brief Return the underlying instruction list container.
///
+ /// Currently you need to access the underlying instruction list container
+ /// directly if you want to modify it.
const InstListType &getInstList() const { return InstList; }
InstListType &getInstList() { return InstList; }
- /// getSublistAccess() - returns pointer to member of instruction list
- static iplist<Instruction> BasicBlock::*getSublistAccess(Instruction*) {
+ /// \brief Returns a pointer to a member of the instruction list.
+ static InstListType BasicBlock::*getSublistAccess(Instruction*) {
return &BasicBlock::InstList;
}
- /// getValueSymbolTable() - returns pointer to symbol table (if any)
+ /// \brief Returns a pointer to the symbol table if one exists.
ValueSymbolTable *getValueSymbolTable();
- /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ /// \brief Methods for support type inquiry through isa, cast, and dyn_cast.
static inline bool classof(const Value *V) {
return V->getValueID() == Value::BasicBlockVal;
}
- /// 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.
+ /// \brief Cause all subinstructions to "let go" of all the references that
+ /// said subinstructions 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();
- /// 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.
+ /// \brief Notify the BasicBlock that the predecessor \p Pred 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, bool DontDeleteUselessPHIs = false);
- /// 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 original 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.
+ bool canSplitPredecessors() const;
+
+ /// \brief Split the basic block into two basic blocks 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 original
+ /// 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
///
/// 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 = "");
+ BasicBlock *splitBasicBlock(Instruction *I, const Twine &BBName = "") {
+ return splitBasicBlock(I->getIterator(), BBName);
+ }
- /// hasAddressTaken - returns true if there are any uses of this basic block
- /// other than direct branches, switches, etc. to it.
+ /// \brief 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.
+ /// \brief Update all phi nodes in this basic block's successors to refer to
+ /// basic block \p New instead of to it.
void replaceSuccessorsPhiUsesWith(BasicBlock *New);
- /// isLandingPad - Return true if this basic block is a landing pad. I.e.,
- /// it's the destination of the 'unwind' edge of an invoke instruction.
+ /// \brief Return true if this basic block is an exception handling block.
+ bool isEHPad() const { return getFirstNonPHI()->isEHPad(); }
+
+ /// \brief Return true if this basic block is a landing pad.
+ ///
+ /// Being a ``landing pad'' means that the basic block is the destination of
+ /// the 'unwind' edge of an invoke instruction.
bool isLandingPad() const;
- /// getLandingPadInst() - Return the landingpad instruction associated with
- /// the landing pad.
+ /// \brief Return the landingpad instruction associated with the landing pad.
LandingPadInst *getLandingPadInst();
const LandingPadInst *getLandingPadInst() const;
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.
+ /// \brief Increment the internal refcount of the number of BlockAddresses
+ /// referencing this BasicBlock by \p Amt.
+ ///
+ /// 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.
+ /// \brief 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);
}
};
+// Create wrappers for C Binding types (see CBindingWrapping.h).
+DEFINE_SIMPLE_CONVERSION_FUNCTIONS(BasicBlock, LLVMBasicBlockRef)
+
} // End llvm namespace
#endif