1 //===- CloneFunction.cpp - Clone a function into another function ---------===//
3 // This file implements the CloneFunctionInto interface, which is used as the
4 // low-level function cloner. This is used by the CloneFunction and function
5 // inliner to do the dirty work of copying the body of a function around.
7 //===----------------------------------------------------------------------===//
9 #include "llvm/Transforms/Utils/Cloning.h"
10 #include "llvm/iTerminators.h"
11 #include "llvm/DerivedTypes.h"
12 #include "llvm/Function.h"
13 #include "ValueMapper.h"
15 // RemapInstruction - Convert the instruction operands from referencing the
16 // current values into those specified by ValueMap.
18 static inline void RemapInstruction(Instruction *I,
19 std::map<const Value *, Value*> &ValueMap) {
20 for (unsigned op = 0, E = I->getNumOperands(); op != E; ++op) {
21 const Value *Op = I->getOperand(op);
22 Value *V = MapValue(Op, ValueMap);
25 std::cerr << "Val = \n" << Op << "Addr = " << (void*)Op;
26 std::cerr << "\nInst = " << I;
29 assert(V && "Referenced value not in value map!");
34 // Clone OldFunc into NewFunc, transforming the old arguments into references to
37 void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
38 std::map<const Value*, Value*> &ValueMap,
39 std::vector<ReturnInst*> &Returns,
40 const char *NameSuffix) {
41 assert(NameSuffix && "NameSuffix cannot be null!");
44 for (Function::const_aiterator I = OldFunc->abegin(), E = OldFunc->aend();
46 assert(ValueMap.count(I) && "No mapping from source argument specified!");
49 // Loop over all of the basic blocks in the function, cloning them as
50 // appropriate. Note that we save BE this way in order to handle cloning of
51 // recursive functions into themselves.
53 for (Function::const_iterator BI = OldFunc->begin(), BE = OldFunc->end();
55 const BasicBlock &BB = *BI;
57 // Create a new basic block to copy instructions into!
58 BasicBlock *CBB = new BasicBlock("", NewFunc);
59 if (BB.hasName()) CBB->setName(BB.getName()+NameSuffix);
60 ValueMap[&BB] = CBB; // Add basic block mapping.
62 // Loop over all instructions copying them over...
63 for (BasicBlock::const_iterator II = BB.begin(), IE = BB.end();
65 Instruction *NewInst = II->clone();
67 NewInst->setName(II->getName()+NameSuffix); // Name is not cloned...
68 CBB->getInstList().push_back(NewInst);
69 ValueMap[II] = NewInst; // Add instruction map to value.
72 if (ReturnInst *RI = dyn_cast<ReturnInst>(CBB->getTerminator()))
73 Returns.push_back(RI);
76 // Loop over all of the instructions in the function, fixing up operand
77 // references as we go. This uses ValueMap to do all the hard work.
79 for (Function::const_iterator BB = OldFunc->begin(), BE = OldFunc->end();
81 BasicBlock *NBB = cast<BasicBlock>(ValueMap[BB]);
83 // Loop over all instructions, fixing each one as we find it...
84 for (BasicBlock::iterator II = NBB->begin(); II != NBB->end(); ++II)
85 RemapInstruction(II, ValueMap);
89 /// CloneFunction - Return a copy of the specified function, but without
90 /// embedding the function into another module. Also, any references specified
91 /// in the ValueMap are changed to refer to their mapped value instead of the
92 /// original one. If any of the arguments to the function are in the ValueMap,
93 /// the arguments are deleted from the resultant function. The ValueMap is
94 /// updated to include mappings from all of the instructions and basicblocks in
95 /// the function from their old to new values.
97 Function *CloneFunction(const Function *F,
98 std::map<const Value*, Value*> &ValueMap) {
99 std::vector<const Type*> ArgTypes;
101 // The user might be deleting arguments to the function by specifying them in
102 // the ValueMap. If so, we need to not add the arguments to the arg ty vector
104 for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
105 if (ValueMap.count(I) == 0) // Haven't mapped the argument to anything yet?
106 ArgTypes.push_back(I->getType());
108 // Create a new function type...
109 FunctionType *FTy = FunctionType::get(F->getFunctionType()->getReturnType(),
110 ArgTypes, F->getFunctionType()->isVarArg());
112 // Create the new function...
113 Function *NewF = new Function(FTy, F->hasInternalLinkage(), F->getName());
115 // Loop over the arguments, copying the names of the mapped arguments over...
116 Function::aiterator DestI = NewF->abegin();
117 for (Function::const_aiterator I = F->abegin(), E = F->aend(); I != E; ++I)
118 if (ValueMap.count(I) == 0) { // Is this argument preserved?
119 DestI->setName(I->getName()); // Copy the name over...
120 ValueMap[I] = DestI++; // Add mapping to ValueMap
123 std::vector<ReturnInst*> Returns; // Ignore returns cloned...
124 CloneFunctionInto(NewF, F, ValueMap, Returns);