//===-- Verifier.cpp - Implement the Module Verifier -------------*- C++ -*-==//
//
-// This file defines the method verifier interface, that can be used for some
+// 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.
//
-// . There are no duplicated names in a symbol table... ie there !exist a val
-// with the same name as something in the symbol table, but with a different
-// address as what is in the symbol table...
-// . Both of a binary operator's parameters are the same type
+// * 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. No adding structures or arrays.
// . 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!]
-// . Right now 'add bool 0, 0' is valid. This isn't particularly good.
-// . 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.
-// . All other things that are tested by asserts spread about the code...
-// . All basic blocks should only end with terminator insts, not contain them
-// . All methods must have >= 1 basic block
+// * 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
// . Verify that none of the Value getType()'s are null.
-// . Method's cannot take a void typed parameter
-// . Verify that a method's argument list agrees with it's declared type.
+// . 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/Method.h"
+#include "llvm/Pass.h"
#include "llvm/Module.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/Type.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/Support/CFG.h"
+#include "llvm/Support/InstVisitor.h"
+#include "Support/STLExtras.h"
+#include <algorithm>
+#include <iostream>
-// Error - Define a macro to do the common task of pushing a message onto the
-// end of the error list and setting Bad to true.
+namespace { // Anonymous namespace for class
+
+ struct Verifier : public FunctionPass, InstVisitor<Verifier> {
+ bool Broken;
+
+ Verifier() : Broken(false) {}
+
+ virtual const char *getPassName() const { return "Module Verifier"; }
+
+ bool doInitialization(Module &M) {
+ verifySymbolTable(M.getSymbolTable());
+ return false;
+ }
+
+ bool runOnFunction(Function &F) {
+ 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) {
+ std::cerr << "Broken module found, compilation aborted!\n";
+ abort();
+ }
+ return false;
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ }
+
+ // 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;
+ }
+ };
+}
+
+// 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
//
-#define Error(msg) do { ErrorMsgs.push_back(msg); Bad = true; } while (0)
+void Verifier::verifySymbolTable(SymbolTable *ST) {
+ if (ST == 0) return; // No symbol table to process
-#define t(x) (1 << (unsigned)Type::x)
+ // 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;
-#define SignedIntegralTypes (t(SByteTyID) | t(ShortTyID) | \
- t(IntTyID) | t(LongTyID))
-static long UnsignedIntegralTypes = t(UByteTyID) | t(UShortTyID) |
- t(UIntTyID) | t(ULongTyID);
-static const long FloatingPointTypes = t(FloatTyID) | t(DoubleTyID);
+ // 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);
+ }
+}
-static const long IntegralTypes = SignedIntegralTypes | UnsignedIntegralTypes;
-#if 0
-static long ValidTypes[Type::FirstDerivedTyID] = {
- [(unsigned)Instruction::UnaryOps::Not] t(BoolTyID),
- //[Instruction::UnaryOps::Add] = IntegralTypes,
- // [Instruction::Sub] = IntegralTypes,
-};
-#endif
+// visitFunction - Verify that a function is ok.
+//
+void Verifier::visitFunction(Function &F) {
+ if (F.isExternal()) return;
-#undef t
+ verifySymbolTable(F.getSymbolTable());
-static bool verify(const BasicBlock *BB, vector<string> &ErrorMsgs) {
- bool Bad = false;
- if (BB->getTerminator() == 0) Error("Basic Block does not have terminator!");
+ // Check function arguments...
+ const FunctionType *FT = F.getFunctionType();
+ unsigned NumArgs = F.getArgumentList().size();
-
- return Bad;
+ 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);
}
-bool verify(const Method *M, vector<string> &ErrorMsgs) {
- bool Bad = false;
-
- for (Method::const_iterator BBIt = M->begin();
- BBIt != M->end(); ++BBIt)
- Bad |= verify(*BBIt, ErrorMsgs);
+// 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);
+}
- return Bad;
+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);
}
-bool verify(const Module *C, vector<string> &ErrorMsgs) {
- bool Bad = false;
- assert(Type::FirstDerivedTyID-1 < sizeof(long)*8 &&
- "Resize ValidTypes table to handle more than 32 primitive types!");
+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());
- for (Module::const_iterator MI = C->begin(); MI != C->end(); ++MI)
- Bad |= verify(*MI, ErrorMsgs);
+ 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);
+ }
- return Bad;
+ // 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 = MemAccessInst::getIndexedType(GEP.getOperand(0)->getType(),
+ GEP.copyIndices(), 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 = LoadInst::getIndexedType(LI.getOperand(0)->getType(),
+ LI.copyIndices());
+ Assert1(ElTy, "Invalid indices for load pointer type!", &LI);
+ Assert2(ElTy == LI.getType(),
+ "Load is not of right type for indices!", &LI, ElTy);
+ visitInstruction(LI);
+}
+
+void Verifier::visitStoreInst(StoreInst &SI) {
+ const Type *ElTy = StoreInst::getIndexedType(SI.getOperand(1)->getType(),
+ SI.copyIndices());
+ Assert1(ElTy, "Invalid indices for store pointer type!", &SI);
+ 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.
+ // FIXME: This should use dominator set information, instead of this local
+ // hack that we have now.
+ //
+ for (User::use_iterator UI = I.use_begin(), UE = I.use_end();
+ UI != UE; ++UI) {
+ Instruction *I2 = cast<Instruction>(*UI);
+ // Same basic block?
+ if (I.getParent() == I2->getParent() && !isa<PHINode>(I2)) {
+ // Make sure the instruction is not before the current instruction...
+ for (Instruction *Test = I.getPrev(); Test != 0; Test = Test->getPrev())
+ Assert2(Test != I2, "Definition of value does not dominate a use!",
+ &I, I2);
+ }
+ }
+
+}
+
+
+//===----------------------------------------------------------------------===//
+// Implement the public interfaces to this file...
+//===----------------------------------------------------------------------===//
+
+Pass *createVerifierPass() {
+ return new Verifier();
+}
+
+bool verifyFunction(const Function &F) {
+ Verifier V;
+ V.visit((Function&)F);
+ 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) {
+ Verifier V;
+ V.run((Module&)M);
+ return V.Broken;
}