/usr/lib/llvm-3.1/include/llvm/BasicBlock.h is in llvm-3.1-dev 3.1-2ubuntu1~12.04.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 | //===-- llvm/BasicBlock.h - Represent a basic block in the VM ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the BasicBlock class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_BASICBLOCK_H
#define LLVM_BASICBLOCK_H
#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 LandingPadInst;
class TerminatorInst;
class LLVMContext;
class BlockAddress;
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;
};
/// 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
/// 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
/// 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
/// are "well formed".
/// @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:
InstListType InstList;
Function *Parent;
void setParent(Function *parent);
friend class SymbolTableListTraits<BasicBlock, Function>;
BasicBlock(const BasicBlock &); // Do not implement
void operator=(const BasicBlock &); // Do not implement
/// 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.
///
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(LLVMContext &Context, const Twine &Name = "",
Function *Parent = 0,BasicBlock *InsertBefore = 0) {
return new BasicBlock(Context, Name, Parent, InsertBefore);
}
~BasicBlock();
/// getParent - 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.
///
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.
Instruction* getFirstNonPHI();
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();
}
// Same as above, but also skip lifetime intrinsics.
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.
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.
///
void removeFromParent();
/// eraseFromParent - This method unlinks 'this' from the containing function
/// 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.
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.
/// 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 {
return const_cast<BasicBlock*>(this)->getUniquePredecessor();
}
//===--------------------------------------------------------------------===//
/// 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 size_t 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; }
/// 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) {
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.
///
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.
///
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.
///
/// 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).
///
/// 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);
/// 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.
bool isLandingPad() const;
/// getLandingPadInst() - 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.
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
#endif
|