| //===-- Verifier.cpp - Implement the Module Verifier -------------*- C++ -*-==// |
| // |
| // This file defines the function verifier interface, that can be used for some |
| // sanity checking of input to the system. |
| // |
| // Note that this does not provide full 'java style' security and verifications, |
| // instead it just tries to ensure that code is well formed. |
| // |
| // * Both of a binary operator's parameters are the same type |
| // * Verify that the indices of mem access instructions match other operands |
| // . Verify that arithmetic and other things are only performed on first class |
| // types. Verify that shifts & logicals only happen on integrals f.e. |
| // . All of the constants in a switch statement are of the correct type |
| // * The code is in valid SSA form |
| // . It should be illegal to put a label into any other type (like a structure) |
| // or to return one. [except constant arrays!] |
| // * Only phi nodes can be self referential: 'add int %0, %0 ; <int>:0' is bad |
| // * PHI nodes must have an entry for each predecessor, with no extras. |
| // * PHI nodes must be the first thing in a basic block, all grouped together |
| // * All basic blocks should only end with terminator insts, not contain them |
| // * The entry node to a function must not have predecessors |
| // * All Instructions must be embeded into a basic block |
| // . Function's cannot take a void typed parameter |
| // * Verify that a function's argument list agrees with it's declared type. |
| // . Verify that arrays and structures have fixed elements: No unsized arrays. |
| // * It is illegal to specify a name for a void value. |
| // * It is illegal to have a internal function that is just a declaration |
| // * It is illegal to have a ret instruction that returns a value that does not |
| // agree with the function return value type. |
| // * Function call argument types match the function prototype |
| // * All other things that are tested by asserts spread about the code... |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/Verifier.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Module.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/iPHINode.h" |
| #include "llvm/iTerminators.h" |
| #include "llvm/iOther.h" |
| #include "llvm/iMemory.h" |
| #include "llvm/SymbolTable.h" |
| #include "llvm/PassManager.h" |
| #include "llvm/Analysis/Dominators.h" |
| #include "llvm/Support/CFG.h" |
| #include "llvm/Support/InstVisitor.h" |
| #include "Support/STLExtras.h" |
| #include <algorithm> |
| #include <iostream> |
| |
| namespace { // Anonymous namespace for class |
| |
| struct Verifier : public FunctionPass, InstVisitor<Verifier> { |
| bool Broken; // Is this module found to be broken? |
| bool RealPass; // Are we not being run by a PassManager? |
| bool AbortBroken; // If broken, should it or should it not abort? |
| |
| DominatorSet *DS; // Dominator set, caution can be null! |
| |
| Verifier() : Broken(false), RealPass(true), AbortBroken(true), DS(0) {} |
| Verifier(bool AB) : Broken(false), RealPass(true), AbortBroken(AB), DS(0) {} |
| Verifier(DominatorSet &ds) |
| : Broken(false), RealPass(false), AbortBroken(false), DS(&ds) {} |
| |
| |
| bool doInitialization(Module &M) { |
| verifySymbolTable(M.getSymbolTable()); |
| return false; |
| } |
| |
| bool runOnFunction(Function &F) { |
| // Get dominator information if we are being run by PassManager |
| if (RealPass) DS = &getAnalysis<DominatorSet>(); |
| visit(F); |
| return false; |
| } |
| |
| bool doFinalization(Module &M) { |
| // Scan through, checking all of the external function's linkage now... |
| for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) |
| if (I->isExternal() && I->hasInternalLinkage()) |
| CheckFailed("Function Declaration has Internal Linkage!", I); |
| |
| if (Broken && AbortBroken) { |
| std::cerr << "Broken module found, compilation aborted!\n"; |
| abort(); |
| } |
| return false; |
| } |
| |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesAll(); |
| if (RealPass) |
| AU.addRequired<DominatorSet>(); |
| } |
| |
| // Verification methods... |
| void verifySymbolTable(SymbolTable *ST); |
| void visitFunction(Function &F); |
| void visitBasicBlock(BasicBlock &BB); |
| void visitPHINode(PHINode &PN); |
| void visitBinaryOperator(BinaryOperator &B); |
| void visitCallInst(CallInst &CI); |
| void visitGetElementPtrInst(GetElementPtrInst &GEP); |
| void visitLoadInst(LoadInst &LI); |
| void visitStoreInst(StoreInst &SI); |
| void visitInstruction(Instruction &I); |
| void visitTerminatorInst(TerminatorInst &I); |
| void visitReturnInst(ReturnInst &RI); |
| |
| // CheckFailed - A check failed, so print out the condition and the message |
| // that failed. This provides a nice place to put a breakpoint if you want |
| // to see why something is not correct. |
| // |
| inline void CheckFailed(const std::string &Message, |
| const Value *V1 = 0, const Value *V2 = 0, |
| const Value *V3 = 0, const Value *V4 = 0) { |
| std::cerr << Message << "\n"; |
| if (V1) std::cerr << *V1 << "\n"; |
| if (V2) std::cerr << *V2 << "\n"; |
| if (V3) std::cerr << *V3 << "\n"; |
| if (V4) std::cerr << *V4 << "\n"; |
| Broken = true; |
| } |
| }; |
| |
| RegisterPass<Verifier> X("verify", "Module Verifier"); |
| } |
| |
| // Assert - We know that cond should be true, if not print an error message. |
| #define Assert(C, M) \ |
| do { if (!(C)) { CheckFailed(M); return; } } while (0) |
| #define Assert1(C, M, V1) \ |
| do { if (!(C)) { CheckFailed(M, V1); return; } } while (0) |
| #define Assert2(C, M, V1, V2) \ |
| do { if (!(C)) { CheckFailed(M, V1, V2); return; } } while (0) |
| #define Assert3(C, M, V1, V2, V3) \ |
| do { if (!(C)) { CheckFailed(M, V1, V2, V3); return; } } while (0) |
| #define Assert4(C, M, V1, V2, V3, V4) \ |
| do { if (!(C)) { CheckFailed(M, V1, V2, V3, V4); return; } } while (0) |
| |
| |
| // verifySymbolTable - Verify that a function or module symbol table is ok |
| // |
| void Verifier::verifySymbolTable(SymbolTable *ST) { |
| if (ST == 0) return; // No symbol table to process |
| |
| // Loop over all of the types in the symbol table... |
| for (SymbolTable::iterator TI = ST->begin(), TE = ST->end(); TI != TE; ++TI) |
| for (SymbolTable::type_iterator I = TI->second.begin(), |
| E = TI->second.end(); I != E; ++I) { |
| Value *V = I->second; |
| |
| // Check that there are no void typed values in the symbol table. Values |
| // with a void type cannot be put into symbol tables because they cannot |
| // have names! |
| Assert1(V->getType() != Type::VoidTy, |
| "Values with void type are not allowed to have names!", V); |
| } |
| } |
| |
| |
| // visitFunction - Verify that a function is ok. |
| // |
| void Verifier::visitFunction(Function &F) { |
| if (F.isExternal()) return; |
| |
| verifySymbolTable(F.getSymbolTable()); |
| |
| // Check function arguments... |
| const FunctionType *FT = F.getFunctionType(); |
| unsigned NumArgs = F.getArgumentList().size(); |
| |
| Assert2(!FT->isVarArg(), "Cannot define varargs functions in LLVM!", &F, FT); |
| Assert2(FT->getParamTypes().size() == NumArgs, |
| "# formal arguments must match # of arguments for function type!", |
| &F, FT); |
| |
| // Check that the argument values match the function type for this function... |
| if (FT->getParamTypes().size() == NumArgs) { |
| unsigned i = 0; |
| for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I, ++i) |
| Assert2(I->getType() == FT->getParamType(i), |
| "Argument value does not match function argument type!", |
| I, FT->getParamType(i)); |
| } |
| |
| // Check the entry node |
| BasicBlock *Entry = &F.getEntryNode(); |
| Assert1(pred_begin(Entry) == pred_end(Entry), |
| "Entry block to function must not have predecessors!", Entry); |
| } |
| |
| |
| // verifyBasicBlock - Verify that a basic block is well formed... |
| // |
| void Verifier::visitBasicBlock(BasicBlock &BB) { |
| // Ensure that basic blocks have terminators! |
| Assert1(BB.getTerminator(), "Basic Block does not have terminator!", &BB); |
| } |
| |
| void Verifier::visitTerminatorInst(TerminatorInst &I) { |
| // Ensure that terminators only exist at the end of the basic block. |
| Assert1(&I == I.getParent()->getTerminator(), |
| "Terminator found in the middle of a basic block!", I.getParent()); |
| visitInstruction(I); |
| } |
| |
| void Verifier::visitReturnInst(ReturnInst &RI) { |
| Function *F = RI.getParent()->getParent(); |
| if (RI.getNumOperands() == 0) |
| Assert1(F->getReturnType() == Type::VoidTy, |
| "Function returns no value, but ret instruction found that does!", |
| &RI); |
| else |
| Assert2(F->getReturnType() == RI.getOperand(0)->getType(), |
| "Function return type does not match operand " |
| "type of return inst!", &RI, F->getReturnType()); |
| |
| // Check to make sure that the return value has neccesary properties for |
| // terminators... |
| visitTerminatorInst(RI); |
| } |
| |
| |
| // visitPHINode - Ensure that a PHI node is well formed. |
| void Verifier::visitPHINode(PHINode &PN) { |
| // Ensure that the PHI nodes are all grouped together at the top of the block. |
| // This can be tested by checking whether the instruction before this is |
| // either nonexistant (because this is begin()) or is a PHI node. If not, |
| // then there is some other instruction before a PHI. |
| Assert2(PN.getPrev() == 0 || isa<PHINode>(PN.getPrev()), |
| "PHI nodes not grouped at top of basic block!", |
| &PN, PN.getParent()); |
| |
| std::vector<BasicBlock*> Preds(pred_begin(PN.getParent()), |
| pred_end(PN.getParent())); |
| // Loop over all of the incoming values, make sure that there are |
| // predecessors for each one... |
| // |
| for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) { |
| // Make sure all of the incoming values are the right types... |
| Assert2(PN.getType() == PN.getIncomingValue(i)->getType(), |
| "PHI node argument type does not agree with PHI node type!", |
| &PN, PN.getIncomingValue(i)); |
| |
| BasicBlock *BB = PN.getIncomingBlock(i); |
| std::vector<BasicBlock*>::iterator PI = |
| find(Preds.begin(), Preds.end(), BB); |
| Assert2(PI != Preds.end(), "PHI node has entry for basic block that" |
| " is not a predecessor!", &PN, BB); |
| Preds.erase(PI); |
| } |
| |
| // There should be no entries left in the predecessor list... |
| for (std::vector<BasicBlock*>::iterator I = Preds.begin(), |
| E = Preds.end(); I != E; ++I) |
| Assert2(0, "PHI node does not have entry for a predecessor basic block!", |
| &PN, *I); |
| |
| // Now we go through and check to make sure that if there is more than one |
| // entry for a particular basic block in this PHI node, that the incoming |
| // values are all identical. |
| // |
| std::vector<std::pair<BasicBlock*, Value*> > Values; |
| Values.reserve(PN.getNumIncomingValues()); |
| for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) |
| Values.push_back(std::make_pair(PN.getIncomingBlock(i), |
| PN.getIncomingValue(i))); |
| |
| // Sort the Values vector so that identical basic block entries are adjacent. |
| std::sort(Values.begin(), Values.end()); |
| |
| // Check for identical basic blocks with differing incoming values... |
| for (unsigned i = 1, e = PN.getNumIncomingValues(); i < e; ++i) |
| Assert4(Values[i].first != Values[i-1].first || |
| Values[i].second == Values[i-1].second, |
| "PHI node has multiple entries for the same basic block with " |
| "different incoming values!", &PN, Values[i].first, |
| Values[i].second, Values[i-1].second); |
| |
| visitInstruction(PN); |
| } |
| |
| void Verifier::visitCallInst(CallInst &CI) { |
| Assert1(isa<PointerType>(CI.getOperand(0)->getType()), |
| "Called function must be a pointer!", &CI); |
| const PointerType *FPTy = cast<PointerType>(CI.getOperand(0)->getType()); |
| Assert1(isa<FunctionType>(FPTy->getElementType()), |
| "Called function is not pointer to function type!", &CI); |
| |
| const FunctionType *FTy = cast<FunctionType>(FPTy->getElementType()); |
| |
| // Verify that the correct number of arguments are being passed |
| if (FTy->isVarArg()) |
| Assert1(CI.getNumOperands()-1 >= FTy->getNumParams(), |
| "Called function requires more parameters than were provided!",&CI); |
| else |
| Assert1(CI.getNumOperands()-1 == FTy->getNumParams(), |
| "Incorrect number of arguments passed to called function!", &CI); |
| |
| // Verify that all arguments to the call match the function type... |
| for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) |
| Assert2(CI.getOperand(i+1)->getType() == FTy->getParamType(i), |
| "Call parameter type does not match function signature!", |
| CI.getOperand(i+1), FTy->getParamType(i)); |
| |
| visitInstruction(CI); |
| } |
| |
| // visitBinaryOperator - Check that both arguments to the binary operator are |
| // of the same type! |
| // |
| void Verifier::visitBinaryOperator(BinaryOperator &B) { |
| Assert2(B.getOperand(0)->getType() == B.getOperand(1)->getType(), |
| "Both operands to a binary operator are not of the same type!", |
| B.getOperand(0), B.getOperand(1)); |
| |
| visitInstruction(B); |
| } |
| |
| void Verifier::visitGetElementPtrInst(GetElementPtrInst &GEP) { |
| const Type *ElTy = |
| GetElementPtrInst::getIndexedType(GEP.getOperand(0)->getType(), |
| std::vector<Value*>(GEP.idx_begin(), GEP.idx_end()), true); |
| Assert1(ElTy, "Invalid indices for GEP pointer type!", &GEP); |
| Assert2(PointerType::get(ElTy) == GEP.getType(), |
| "GEP is not of right type for indices!", &GEP, ElTy); |
| visitInstruction(GEP); |
| } |
| |
| void Verifier::visitLoadInst(LoadInst &LI) { |
| const Type *ElTy = |
| cast<PointerType>(LI.getOperand(0)->getType())->getElementType(); |
| Assert2(ElTy == LI.getType(), |
| "Load is not of right type for indices!", &LI, ElTy); |
| visitInstruction(LI); |
| } |
| |
| void Verifier::visitStoreInst(StoreInst &SI) { |
| const Type *ElTy = |
| cast<PointerType>(SI.getOperand(1)->getType())->getElementType(); |
| Assert2(ElTy == SI.getOperand(0)->getType(), |
| "Stored value is not of right type for indices!", &SI, ElTy); |
| visitInstruction(SI); |
| } |
| |
| |
| // verifyInstruction - Verify that an instruction is well formed. |
| // |
| void Verifier::visitInstruction(Instruction &I) { |
| Assert1(I.getParent(), "Instruction not embedded in basic block!", &I); |
| |
| // Check that all uses of the instruction, if they are instructions |
| // themselves, actually have parent basic blocks. If the use is not an |
| // instruction, it is an error! |
| // |
| for (User::use_iterator UI = I.use_begin(), UE = I.use_end(); |
| UI != UE; ++UI) { |
| Assert1(isa<Instruction>(*UI), "Use of instruction is not an instruction!", |
| *UI); |
| Instruction *Used = cast<Instruction>(*UI); |
| Assert2(Used->getParent() != 0, "Instruction referencing instruction not" |
| " embeded in a basic block!", &I, Used); |
| } |
| |
| if (!isa<PHINode>(I)) { // Check that non-phi nodes are not self referential |
| for (Value::use_iterator UI = I.use_begin(), UE = I.use_end(); |
| UI != UE; ++UI) |
| Assert1(*UI != (User*)&I, |
| "Only PHI nodes may reference their own value!", &I); |
| } |
| |
| // Check that void typed values don't have names |
| Assert1(I.getType() != Type::VoidTy || !I.hasName(), |
| "Instruction has a name, but provides a void value!", &I); |
| |
| // Check that a definition dominates all of its uses. |
| // |
| for (User::use_iterator UI = I.use_begin(), UE = I.use_end(); |
| UI != UE; ++UI) { |
| Instruction *Use = cast<Instruction>(*UI); |
| |
| // PHI nodes are more difficult than other nodes because they actually |
| // "use" the value in the predecessor basic blocks they correspond to. |
| if (PHINode *PN = dyn_cast<PHINode>(Use)) { |
| for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) |
| if (&I == PN->getIncomingValue(i)) { |
| // Make sure that I dominates the end of pred(i) |
| BasicBlock *Pred = PN->getIncomingBlock(i); |
| |
| Assert2(DS->dominates(I.getParent(), Pred), |
| "Instruction does not dominate all uses!", |
| &I, PN); |
| } |
| |
| } else { |
| Assert2(DS->dominates(&I, Use), |
| "Instruction does not dominate all uses!", &I, Use); |
| } |
| } |
| } |
| |
| |
| //===----------------------------------------------------------------------===// |
| // Implement the public interfaces to this file... |
| //===----------------------------------------------------------------------===// |
| |
| Pass *createVerifierPass() { |
| return new Verifier(); |
| } |
| |
| |
| // verifyFunction - Create |
| bool verifyFunction(const Function &f) { |
| Function &F = (Function&)f; |
| assert(!F.isExternal() && "Cannot verify external functions"); |
| |
| DominatorSet DS; |
| DS.doInitialization(*F.getParent()); |
| DS.runOnFunction(F); |
| |
| Verifier V(DS); |
| V.runOnFunction(F); |
| |
| DS.doFinalization(*F.getParent()); |
| |
| return V.Broken; |
| } |
| |
| // verifyModule - Check a module for errors, printing messages on stderr. |
| // Return true if the module is corrupt. |
| // |
| bool verifyModule(const Module &M) { |
| PassManager PM; |
| Verifier *V = new Verifier(); |
| PM.add(V); |
| PM.run((Module&)M); |
| return V->Broken; |
| } |