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      1 //===- ValueMapper.h - Remapping for constants and metadata -----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the MapValue interface which is used by various parts of
     11 // the Transforms/Utils library to implement cloning and linking facilities.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_TRANSFORMS_UTILS_VALUEMAPPER_H
     16 #define LLVM_TRANSFORMS_UTILS_VALUEMAPPER_H
     17 
     18 #include "llvm/ADT/ValueMap.h"
     19 
     20 namespace llvm {
     21   class Value;
     22   class Instruction;
     23   typedef ValueMap<const Value *, WeakVH> ValueToValueMapTy;
     24 
     25   /// ValueMapTypeRemapper - This is a class that can be implemented by clients
     26   /// to remap types when cloning constants and instructions.
     27   class ValueMapTypeRemapper {
     28     virtual void anchor();  // Out of line method.
     29   public:
     30     virtual ~ValueMapTypeRemapper() {}
     31 
     32     /// remapType - The client should implement this method if they want to
     33     /// remap types while mapping values.
     34     virtual Type *remapType(Type *SrcTy) = 0;
     35   };
     36 
     37   /// ValueMaterializer - This is a class that can be implemented by clients
     38   /// to materialize Values on demand.
     39   class ValueMaterializer {
     40     virtual void anchor(); // Out of line method.
     41   public:
     42     virtual ~ValueMaterializer() {}
     43 
     44     /// materializeValueFor - The client should implement this method if they
     45     /// want to generate a mapped Value on demand. For example, if linking
     46     /// lazily.
     47     virtual Value *materializeValueFor(Value *V) = 0;
     48   };
     49 
     50   /// RemapFlags - These are flags that the value mapping APIs allow.
     51   enum RemapFlags {
     52     RF_None = 0,
     53 
     54     /// RF_NoModuleLevelChanges - If this flag is set, the remapper knows that
     55     /// only local values within a function (such as an instruction or argument)
     56     /// are mapped, not global values like functions and global metadata.
     57     RF_NoModuleLevelChanges = 1,
     58 
     59     /// RF_IgnoreMissingEntries - If this flag is set, the remapper ignores
     60     /// entries that are not in the value map.  If it is unset, it aborts if an
     61     /// operand is asked to be remapped which doesn't exist in the mapping.
     62     RF_IgnoreMissingEntries = 2
     63   };
     64 
     65   static inline RemapFlags operator|(RemapFlags LHS, RemapFlags RHS) {
     66     return RemapFlags(unsigned(LHS)|unsigned(RHS));
     67   }
     68 
     69   Value *MapValue(const Value *V, ValueToValueMapTy &VM,
     70                   RemapFlags Flags = RF_None,
     71                   ValueMapTypeRemapper *TypeMapper = 0,
     72                   ValueMaterializer *Materializer = 0);
     73 
     74   void RemapInstruction(Instruction *I, ValueToValueMapTy &VM,
     75                         RemapFlags Flags = RF_None,
     76                         ValueMapTypeRemapper *TypeMapper = 0,
     77                         ValueMaterializer *Materializer = 0);
     78 
     79   /// MapValue - provide versions that preserve type safety for MDNode and
     80   /// Constants.
     81   inline MDNode *MapValue(const MDNode *V, ValueToValueMapTy &VM,
     82                           RemapFlags Flags = RF_None,
     83                           ValueMapTypeRemapper *TypeMapper = 0,
     84                           ValueMaterializer *Materializer = 0) {
     85     return cast<MDNode>(MapValue((const Value*)V, VM, Flags, TypeMapper,
     86                                  Materializer));
     87   }
     88   inline Constant *MapValue(const Constant *V, ValueToValueMapTy &VM,
     89                             RemapFlags Flags = RF_None,
     90                             ValueMapTypeRemapper *TypeMapper = 0,
     91                             ValueMaterializer *Materializer = 0) {
     92     return cast<Constant>(MapValue((const Value*)V, VM, Flags, TypeMapper,
     93                                    Materializer));
     94   }
     95 
     96 
     97 } // End llvm namespace
     98 
     99 #endif
    100