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Diffstat (limited to 'include/llvm/IR/InstVisitor.h')
| -rw-r--r-- | include/llvm/IR/InstVisitor.h | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/include/llvm/IR/InstVisitor.h b/include/llvm/IR/InstVisitor.h new file mode 100644 index 0000000..1cdcd55 --- /dev/null +++ b/include/llvm/IR/InstVisitor.h @@ -0,0 +1,289 @@ +//===- InstVisitor.h - Instruction visitor templates ------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + + +#ifndef LLVM_IR_INSTVISITOR_H +#define LLVM_IR_INSTVISITOR_H + +#include "llvm/IR/CallSite.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/Module.h" +#include "llvm/Support/ErrorHandling.h" + +namespace llvm { + +// We operate on opaque instruction classes, so forward declare all instruction +// types now... +// +#define HANDLE_INST(NUM, OPCODE, CLASS) class CLASS; +#include "llvm/IR/Instruction.def" + +#define DELEGATE(CLASS_TO_VISIT) \ + return static_cast<SubClass*>(this)-> \ + visit##CLASS_TO_VISIT(static_cast<CLASS_TO_VISIT&>(I)) + + +/// @brief Base class for instruction visitors +/// +/// Instruction visitors are used when you want to perform different actions +/// for different kinds of instructions without having to use lots of casts +/// and a big switch statement (in your code, that is). +/// +/// To define your own visitor, inherit from this class, specifying your +/// new type for the 'SubClass' template parameter, and "override" visitXXX +/// functions in your class. I say "override" because this class is defined +/// in terms of statically resolved overloading, not virtual functions. +/// +/// For example, here is a visitor that counts the number of malloc +/// instructions processed: +/// +/// /// Declare the class. Note that we derive from InstVisitor instantiated +/// /// with _our new subclasses_ type. +/// /// +/// struct CountAllocaVisitor : public InstVisitor<CountAllocaVisitor> { +/// unsigned Count; +/// CountAllocaVisitor() : Count(0) {} +/// +/// void visitAllocaInst(AllocaInst &AI) { ++Count; } +/// }; +/// +/// And this class would be used like this: +/// CountAllocaVisitor CAV; +/// CAV.visit(function); +/// NumAllocas = CAV.Count; +/// +/// The defined has 'visit' methods for Instruction, and also for BasicBlock, +/// Function, and Module, which recursively process all contained instructions. +/// +/// Note that if you don't implement visitXXX for some instruction type, +/// the visitXXX method for instruction superclass will be invoked. So +/// if instructions are added in the future, they will be automatically +/// supported, if you handle one of their superclasses. +/// +/// The optional second template argument specifies the type that instruction +/// visitation functions should return. If you specify this, you *MUST* provide +/// an implementation of visitInstruction though!. +/// +/// Note that this class is specifically designed as a template to avoid +/// virtual function call overhead. Defining and using an InstVisitor is just +/// as efficient as having your own switch statement over the instruction +/// opcode. +template<typename SubClass, typename RetTy=void> +class InstVisitor { + //===--------------------------------------------------------------------===// + // Interface code - This is the public interface of the InstVisitor that you + // use to visit instructions... + // + +public: + // Generic visit method - Allow visitation to all instructions in a range + template<class Iterator> + void visit(Iterator Start, Iterator End) { + while (Start != End) + static_cast<SubClass*>(this)->visit(*Start++); + } + + // Define visitors for functions and basic blocks... + // + void visit(Module &M) { + static_cast<SubClass*>(this)->visitModule(M); + visit(M.begin(), M.end()); + } + void visit(Function &F) { + static_cast<SubClass*>(this)->visitFunction(F); + visit(F.begin(), F.end()); + } + void visit(BasicBlock &BB) { + static_cast<SubClass*>(this)->visitBasicBlock(BB); + visit(BB.begin(), BB.end()); + } + + // Forwarding functions so that the user can visit with pointers AND refs. + void visit(Module *M) { visit(*M); } + void visit(Function *F) { visit(*F); } + void visit(BasicBlock *BB) { visit(*BB); } + RetTy visit(Instruction *I) { return visit(*I); } + + // visit - Finally, code to visit an instruction... + // + RetTy visit(Instruction &I) { + switch (I.getOpcode()) { + default: llvm_unreachable("Unknown instruction type encountered!"); + // Build the switch statement using the Instruction.def file... +#define HANDLE_INST(NUM, OPCODE, CLASS) \ + case Instruction::OPCODE: return \ + static_cast<SubClass*>(this)-> \ + visit##OPCODE(static_cast<CLASS&>(I)); +#include "llvm/IR/Instruction.def" + } + } + + //===--------------------------------------------------------------------===// + // Visitation functions... these functions provide default fallbacks in case + // the user does not specify what to do for a particular instruction type. + // The default behavior is to generalize the instruction type to its subtype + // and try visiting the subtype. All of this should be inlined perfectly, + // because there are no virtual functions to get in the way. + // + + // When visiting a module, function or basic block directly, these methods get + // called to indicate when transitioning into a new unit. + // + void visitModule (Module &M) {} + void visitFunction (Function &F) {} + void visitBasicBlock(BasicBlock &BB) {} + + // Define instruction specific visitor functions that can be overridden to + // handle SPECIFIC instructions. These functions automatically define + // visitMul to proxy to visitBinaryOperator for instance in case the user does + // not need this generality. + // + // These functions can also implement fan-out, when a single opcode and + // instruction have multiple more specific Instruction subclasses. The Call + // instruction currently supports this. We implement that by redirecting that + // instruction to a special delegation helper. +#define HANDLE_INST(NUM, OPCODE, CLASS) \ + RetTy visit##OPCODE(CLASS &I) { \ + if (NUM == Instruction::Call) \ + return delegateCallInst(I); \ + else \ + DELEGATE(CLASS); \ + } +#include "llvm/IR/Instruction.def" + + // Specific Instruction type classes... note that all of the casts are + // necessary because we use the instruction classes as opaque types... + // + RetTy visitReturnInst(ReturnInst &I) { DELEGATE(TerminatorInst);} + RetTy visitBranchInst(BranchInst &I) { DELEGATE(TerminatorInst);} + RetTy visitSwitchInst(SwitchInst &I) { DELEGATE(TerminatorInst);} + RetTy visitIndirectBrInst(IndirectBrInst &I) { DELEGATE(TerminatorInst);} + RetTy visitResumeInst(ResumeInst &I) { DELEGATE(TerminatorInst);} + RetTy visitUnreachableInst(UnreachableInst &I) { DELEGATE(TerminatorInst);} + RetTy visitICmpInst(ICmpInst &I) { DELEGATE(CmpInst);} + RetTy visitFCmpInst(FCmpInst &I) { DELEGATE(CmpInst);} + RetTy visitAllocaInst(AllocaInst &I) { DELEGATE(UnaryInstruction);} + RetTy visitLoadInst(LoadInst &I) { DELEGATE(UnaryInstruction);} + RetTy visitStoreInst(StoreInst &I) { DELEGATE(Instruction);} + RetTy visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) { DELEGATE(Instruction);} + RetTy visitAtomicRMWInst(AtomicRMWInst &I) { DELEGATE(Instruction);} + RetTy visitFenceInst(FenceInst &I) { DELEGATE(Instruction);} + RetTy visitGetElementPtrInst(GetElementPtrInst &I){ DELEGATE(Instruction);} + RetTy visitPHINode(PHINode &I) { DELEGATE(Instruction);} + RetTy visitTruncInst(TruncInst &I) { DELEGATE(CastInst);} + RetTy visitZExtInst(ZExtInst &I) { DELEGATE(CastInst);} + RetTy visitSExtInst(SExtInst &I) { DELEGATE(CastInst);} + RetTy visitFPTruncInst(FPTruncInst &I) { DELEGATE(CastInst);} + RetTy visitFPExtInst(FPExtInst &I) { DELEGATE(CastInst);} + RetTy visitFPToUIInst(FPToUIInst &I) { DELEGATE(CastInst);} + RetTy visitFPToSIInst(FPToSIInst &I) { DELEGATE(CastInst);} + RetTy visitUIToFPInst(UIToFPInst &I) { DELEGATE(CastInst);} + RetTy visitSIToFPInst(SIToFPInst &I) { DELEGATE(CastInst);} + RetTy visitPtrToIntInst(PtrToIntInst &I) { DELEGATE(CastInst);} + RetTy visitIntToPtrInst(IntToPtrInst &I) { DELEGATE(CastInst);} + RetTy visitBitCastInst(BitCastInst &I) { DELEGATE(CastInst);} + RetTy visitAddrSpaceCastInst(AddrSpaceCastInst &I) { DELEGATE(CastInst);} + RetTy visitSelectInst(SelectInst &I) { DELEGATE(Instruction);} + RetTy visitVAArgInst(VAArgInst &I) { DELEGATE(UnaryInstruction);} + RetTy visitExtractElementInst(ExtractElementInst &I) { DELEGATE(Instruction);} + RetTy visitInsertElementInst(InsertElementInst &I) { DELEGATE(Instruction);} + RetTy visitShuffleVectorInst(ShuffleVectorInst &I) { DELEGATE(Instruction);} + RetTy visitExtractValueInst(ExtractValueInst &I){ DELEGATE(UnaryInstruction);} + RetTy visitInsertValueInst(InsertValueInst &I) { DELEGATE(Instruction); } + RetTy visitLandingPadInst(LandingPadInst &I) { DELEGATE(Instruction); } + + // Handle the special instrinsic instruction classes. + RetTy visitDbgDeclareInst(DbgDeclareInst &I) { DELEGATE(DbgInfoIntrinsic);} + RetTy visitDbgValueInst(DbgValueInst &I) { DELEGATE(DbgInfoIntrinsic);} + RetTy visitDbgInfoIntrinsic(DbgInfoIntrinsic &I) { DELEGATE(IntrinsicInst); } + RetTy visitMemSetInst(MemSetInst &I) { DELEGATE(MemIntrinsic); } + RetTy visitMemCpyInst(MemCpyInst &I) { DELEGATE(MemTransferInst); } + RetTy visitMemMoveInst(MemMoveInst &I) { DELEGATE(MemTransferInst); } + RetTy visitMemTransferInst(MemTransferInst &I) { DELEGATE(MemIntrinsic); } + RetTy visitMemIntrinsic(MemIntrinsic &I) { DELEGATE(IntrinsicInst); } + RetTy visitVAStartInst(VAStartInst &I) { DELEGATE(IntrinsicInst); } + RetTy visitVAEndInst(VAEndInst &I) { DELEGATE(IntrinsicInst); } + RetTy visitVACopyInst(VACopyInst &I) { DELEGATE(IntrinsicInst); } + RetTy visitIntrinsicInst(IntrinsicInst &I) { DELEGATE(CallInst); } + + // Call and Invoke are slightly different as they delegate first through + // a generic CallSite visitor. + RetTy visitCallInst(CallInst &I) { + return static_cast<SubClass*>(this)->visitCallSite(&I); + } + RetTy visitInvokeInst(InvokeInst &I) { + return static_cast<SubClass*>(this)->visitCallSite(&I); + } + + // Next level propagators: If the user does not overload a specific + // instruction type, they can overload one of these to get the whole class + // of instructions... + // + RetTy visitCastInst(CastInst &I) { DELEGATE(UnaryInstruction);} + RetTy visitBinaryOperator(BinaryOperator &I) { DELEGATE(Instruction);} + RetTy visitCmpInst(CmpInst &I) { DELEGATE(Instruction);} + RetTy visitTerminatorInst(TerminatorInst &I) { DELEGATE(Instruction);} + RetTy visitUnaryInstruction(UnaryInstruction &I){ DELEGATE(Instruction);} + + // Provide a special visitor for a 'callsite' that visits both calls and + // invokes. When unimplemented, properly delegates to either the terminator or + // regular instruction visitor. + RetTy visitCallSite(CallSite CS) { + assert(CS); + Instruction &I = *CS.getInstruction(); + if (CS.isCall()) + DELEGATE(Instruction); + + assert(CS.isInvoke()); + DELEGATE(TerminatorInst); + } + + // If the user wants a 'default' case, they can choose to override this + // function. If this function is not overloaded in the user's subclass, then + // this instruction just gets ignored. + // + // Note that you MUST override this function if your return type is not void. + // + void visitInstruction(Instruction &I) {} // Ignore unhandled instructions + +private: + // Special helper function to delegate to CallInst subclass visitors. + RetTy delegateCallInst(CallInst &I) { + if (const Function *F = I.getCalledFunction()) { + switch ((Intrinsic::ID)F->getIntrinsicID()) { + default: DELEGATE(IntrinsicInst); + case Intrinsic::dbg_declare: DELEGATE(DbgDeclareInst); + case Intrinsic::dbg_value: DELEGATE(DbgValueInst); + case Intrinsic::memcpy: DELEGATE(MemCpyInst); + case Intrinsic::memmove: DELEGATE(MemMoveInst); + case Intrinsic::memset: DELEGATE(MemSetInst); + case Intrinsic::vastart: DELEGATE(VAStartInst); + case Intrinsic::vaend: DELEGATE(VAEndInst); + case Intrinsic::vacopy: DELEGATE(VACopyInst); + case Intrinsic::not_intrinsic: break; + } + } + DELEGATE(CallInst); + } + + // An overload that will never actually be called, it is used only from dead + // code in the dispatching from opcodes to instruction subclasses. + RetTy delegateCallInst(Instruction &I) { + llvm_unreachable("delegateCallInst called for non-CallInst"); + } +}; + +#undef DELEGATE + +} // End llvm namespace + +#endif |