* Add a comment to the header giving a breif overview of how to return a

value from a visit function
* Define a (file local) DELEGATE macro to make the code easier to read/maintain
* Define per-opcode delegation functions so that users can override specific
  instances of BinaryOperator for example.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2290 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-04-18 16:16:16 +00:00
parent 536fe85d6d
commit 0e743b8397

View File

@ -32,6 +32,12 @@
// CMV.visit(function);
// NumMallocs = CMV.Count;
//
// Returning a value from the visitation function:
// The InstVisitor class takes an optional second template argument that
// specifies what type the instruction visitation functions should return. If
// you specify this, you *MUST* provide an implementation of visitInstruction
// though!.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_INSTVISITOR_H
@ -49,6 +55,11 @@
class TerminatorInst; class UnaryOperator; class BinaryOperator;
class AllocationInst; class MemAccessInst;
#define DELEGATE(CLASS_TO_VISIT) \
return ((SubClass*)this)->visit##CLASS_TO_VISIT((CLASS_TO_VISIT*)I)
template<typename SubClass, typename RetTy=void>
struct InstVisitor {
virtual ~InstVisitor() {} // We are meant to be derived from
@ -86,7 +97,7 @@ struct InstVisitor {
switch (I->getOpcode()) {
// Build the switch statement using the Instruction.def file...
#define HANDLE_INST(NUM, OPCODE, CLASS) \
case Instruction::OPCODE: return ((SubClass*)this)->visit##CLASS((CLASS*)I);
case Instruction::OPCODE:return ((SubClass*)this)->visit##OPCODE((CLASS*)I);
#include "llvm/Instruction.def"
default: assert(0 && "Unknown instruction type encountered!");
@ -107,37 +118,63 @@ struct InstVisitor {
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.
//
// The one problem case we have to handle here though is that the PHINode
// class and opcode name are the exact same. Because of this, we cannot
// define visitPHINode (the inst version) to forward to visitPHINode (the
// generic version) without multiply defined symbols and recursion. To handle
// this, we do not autoexpand "Other" instructions, we do it manually.
//
#define HANDLE_INST(NUM, OPCODE, CLASS) \
RetTy visit##OPCODE(CLASS *I) { DELEGATE(CLASS); }
#define HANDLE_OTHER_INST(NUM, OPCODE, CLASS) // Ignore "other" instructions
#include "llvm/Instruction.def"
// Implement all "other" instructions, except for PHINode
RetTy visitCast(CastInst *I) { DELEGATE(CastInst); }
RetTy visitCall(CallInst *I) { DELEGATE(CallInst); }
RetTy visitShr(ShiftInst *I) { DELEGATE(ShiftInst); }
RetTy visitShl(ShiftInst *I) { DELEGATE(ShiftInst); }
RetTy visitUserOp1(Instruction *I) { DELEGATE(Instruction); }
RetTy visitUserOp2(Instruction *I) { DELEGATE(Instruction); }
// Specific Instruction type classes... note that all of the casts are
// neccesary because we use the instruction classes as opaque types...
//
RetTy visitReturnInst(ReturnInst *I) { return ((SubClass*)this)->visitTerminatorInst((TerminatorInst*)I); }
RetTy visitBranchInst(BranchInst *I) { return ((SubClass*)this)->visitTerminatorInst((TerminatorInst*)I); }
RetTy visitSwitchInst(SwitchInst *I) { return ((SubClass*)this)->visitTerminatorInst((TerminatorInst*)I); }
RetTy visitInvokeInst(InvokeInst *I) { return ((SubClass*)this)->visitTerminatorInst((TerminatorInst*)I); }
RetTy visitGenericUnaryInst(GenericUnaryInst *I) { return ((SubClass*)this)->visitUnaryOperator((UnaryOperator*)I); }
RetTy visitGenericBinaryInst(GenericBinaryInst *I) { return ((SubClass*)this)->visitBinaryOperator((BinaryOperator*)I); }
RetTy visitSetCondInst(SetCondInst *I) { return ((SubClass*)this)->visitBinaryOperator((BinaryOperator *)I); }
RetTy visitMallocInst(MallocInst *I) { return ((SubClass*)this)->visitAllocationInst((AllocationInst *)I); }
RetTy visitAllocaInst(AllocaInst *I) { return ((SubClass*)this)->visitAllocationInst((AllocationInst *)I); }
RetTy visitFreeInst(FreeInst *I) { return ((SubClass*)this)->visitInstruction((Instruction *)I); }
RetTy visitLoadInst(LoadInst *I) { return ((SubClass*)this)->visitMemAccessInst((MemAccessInst *)I); }
RetTy visitStoreInst(StoreInst *I) { return ((SubClass*)this)->visitMemAccessInst((MemAccessInst *)I); }
RetTy visitGetElementPtrInst(GetElementPtrInst *I) { return ((SubClass*)this)->visitMemAccessInst((MemAccessInst *)I); }
RetTy visitPHINode(PHINode *I) { return ((SubClass*)this)->visitInstruction((Instruction *)I); }
RetTy visitCastInst(CastInst *I) { return ((SubClass*)this)->visitInstruction((Instruction *)I); }
RetTy visitCallInst(CallInst *I) { return ((SubClass*)this)->visitInstruction((Instruction *)I); }
RetTy visitShiftInst(ShiftInst *I) { return ((SubClass*)this)->visitInstruction((Instruction *)I); }
RetTy visitReturnInst(ReturnInst *I) { DELEGATE(TerminatorInst);}
RetTy visitBranchInst(BranchInst *I) { DELEGATE(TerminatorInst);}
RetTy visitSwitchInst(SwitchInst *I) { DELEGATE(TerminatorInst);}
RetTy visitInvokeInst(InvokeInst *I) { DELEGATE(TerminatorInst);}
RetTy visitGenericUnaryInst(GenericUnaryInst *I) { DELEGATE(UnaryOperator); }
RetTy visitGenericBinaryInst(GenericBinaryInst *I){ DELEGATE(BinaryOperator);}
RetTy visitSetCondInst(SetCondInst *I) { DELEGATE(BinaryOperator);}
RetTy visitMallocInst(MallocInst *I) { DELEGATE(AllocationInst);}
RetTy visitAllocaInst(AllocaInst *I) { DELEGATE(AllocationInst);}
RetTy visitFreeInst(FreeInst *I) { DELEGATE(Instruction); }
RetTy visitLoadInst(LoadInst *I) { DELEGATE(MemAccessInst); }
RetTy visitStoreInst(StoreInst *I) { DELEGATE(MemAccessInst); }
RetTy visitGetElementPtrInst(GetElementPtrInst *I){ DELEGATE(MemAccessInst); }
RetTy visitPHINode(PHINode *I) { DELEGATE(Instruction); }
RetTy visitCastInst(CastInst *I) { DELEGATE(Instruction); }
RetTy visitCallInst(CallInst *I) { DELEGATE(Instruction); }
RetTy visitShiftInst(ShiftInst *I) { DELEGATE(Instruction); }
// Next level propogators... if the user does not overload a specific
// instruction type, they can overload one of these to get the whole class
// of instructions...
//
RetTy visitTerminatorInst(TerminatorInst *I) { return ((SubClass*)this)->visitInstruction((Instruction*)I); }
RetTy visitUnaryOperator (UnaryOperator *I) { return ((SubClass*)this)->visitInstruction((Instruction*)I); }
RetTy visitBinaryOperator(BinaryOperator *I) { return ((SubClass*)this)->visitInstruction((Instruction*)I); }
RetTy visitAllocationInst(AllocationInst *I) { return ((SubClass*)this)->visitInstruction((Instruction*)I); }
RetTy visitMemAccessInst (MemAccessInst *I) { return ((SubClass*)this)->visitInstruction((Instruction*)I); }
RetTy visitTerminatorInst(TerminatorInst *I) { DELEGATE(Instruction); }
RetTy visitUnaryOperator (UnaryOperator *I) { DELEGATE(Instruction); }
RetTy visitBinaryOperator(BinaryOperator *I) { DELEGATE(Instruction); }
RetTy visitAllocationInst(AllocationInst *I) { DELEGATE(Instruction); }
RetTy visitMemAccessInst (MemAccessInst *I) { DELEGATE(Instruction); }
// If the user wants a 'default' case, they can choose to override this
// function. If this function is not overloaded in the users subclass, then
@ -148,4 +185,6 @@ struct InstVisitor {
void visitInstruction(Instruction *I) {} // Ignore unhandled instructions
};
#undef DELEGATE
#endif