1 //===-- Verifier.cpp - Implement the Module Verifier -------------*- C++ -*-==//
3 // This file defines the function verifier interface, that can be used for some
4 // sanity checking of input to the system.
6 // Note that this does not provide full 'java style' security and verifications,
7 // instead it just tries to ensure that code is well formed.
9 // . There are no duplicated names in a symbol table... ie there !exist a val
10 // with the same name as something in the symbol table, but with a different
11 // address as what is in the symbol table...
12 // . Both of a binary operator's parameters are the same type
13 // . Verify that arithmetic and other things are only performed on first class
14 // types. No adding structures or arrays.
15 // . All of the constants in a switch statement are of the correct type
16 // . The code is in valid SSA form
17 // . It should be illegal to put a label into any other type (like a structure)
18 // or to return one. [except constant arrays!]
19 // . Right now 'add bool 0, 0' is valid. This isn't particularly good.
20 // * Only phi nodes can be self referential: 'add int %0, %0 ; <int>:0' is bad
21 // * PHI nodes must have an entry for each predecessor, with no extras.
22 // * All basic blocks should only end with terminator insts, not contain them
23 // * The entry node to a function must not have predecessors
24 // * All Instructions must be embeded into a basic block
25 // . Verify that none of the Value getType()'s are null.
26 // . Function's cannot take a void typed parameter
27 // . Verify that a function's argument list agrees with it's declared type.
28 // . Verify that arrays and structures have fixed elements: No unsized arrays.
29 // * It is illegal to specify a name for a void value.
30 // * It is illegal to have a internal function that is just a declaration
31 // * It is illegal to have a ret instruction that returns a value that does not
32 // agree with the function return value type.
33 // . All other things that are tested by asserts spread about the code...
35 //===----------------------------------------------------------------------===//
37 #include "llvm/Analysis/Verifier.h"
38 #include "llvm/Pass.h"
39 #include "llvm/Function.h"
40 #include "llvm/Module.h"
41 #include "llvm/BasicBlock.h"
42 #include "llvm/Type.h"
43 #include "llvm/iPHINode.h"
44 #include "llvm/iTerminators.h"
45 #include "llvm/SymbolTable.h"
46 #include "llvm/Support/CFG.h"
47 #include "Support/STLExtras.h"
51 #define t(x) (1 << (unsigned)Type::x)
52 #define SignedIntegralTypes (t(SByteTyID) | t(ShortTyID) | \
53 t(IntTyID) | t(LongTyID))
54 static long UnsignedIntegralTypes = t(UByteTyID) | t(UShortTyID) |
55 t(UIntTyID) | t(ULongTyID);
56 static const long FloatingPointTypes = t(FloatTyID) | t(DoubleTyID);
58 static const long IntegralTypes = SignedIntegralTypes | UnsignedIntegralTypes;
60 static long ValidTypes[Type::FirstDerivedTyID] = {
61 [(unsigned)Instruction::UnaryOps::Not] t(BoolTyID),
62 //[Instruction::UnaryOps::Add] = IntegralTypes,
63 // [Instruction::Sub] = IntegralTypes,
68 // CheckFailed - A check failed, so print out the condition and the message that
69 // failed. This provides a nice place to put a breakpoint if you want to see
70 // why something is not correct.
72 static inline void CheckFailed(const char *Cond, const std::string &Message,
73 const Value *V1 = 0, const Value *V2 = 0) {
74 std::cerr << Message << "\n";
75 if (V1) { std::cerr << V1 << "\n"; }
76 if (V2) { std::cerr << V2 << "\n"; }
79 // Assert - We know that cond should be true, if not print an error message.
80 #define Assert(C, M) \
81 do { if (!(C)) { CheckFailed(#C, M); Broken = true; } } while (0)
82 #define Assert1(C, M, V1) \
83 do { if (!(C)) { CheckFailed(#C, M, V1); Broken = true; } } while (0)
84 #define Assert2(C, M, V1, V2) \
85 do { if (!(C)) { CheckFailed(#C, M, V1, V2); Broken = true; } } while (0)
88 // verifyInstruction - Verify that a non-terminator instruction is well formed.
90 static bool verifyInstruction(const Instruction *I) {
92 assert(I->getParent() && "Instruction not embedded in basic block!");
93 Assert1(!isa<TerminatorInst>(I),
94 "Terminator instruction found embedded in basic block!\n", I);
96 if (isa<ReturnInst>(I)) {
97 const Function *F = I->getParent()->getParent();
98 if (I->getNumOperands() == 0)
99 Assert1(F->getReturnType() == Type::VoidTy,
100 "Function returns no value, but ret instruction found that does!",
103 Assert2(F->getReturnType() == I->getOperand(0)->getType(),
104 "Function return type does not match operand "
105 "type of return inst!", I, F->getReturnType());
108 // Check that all uses of the instruction, if they are instructions
109 // themselves, actually have parent basic blocks.
111 for (User::use_const_iterator UI = I->use_begin(), UE = I->use_end();
113 if (Instruction *Used = dyn_cast<Instruction>(*UI))
114 Assert2(Used->getParent() != 0, "Instruction referencing instruction not"
115 " embeded in a basic block!", I, Used);
118 // Check that PHI nodes look ok
119 if (const PHINode *PN = dyn_cast<PHINode>(I)) {
120 std::vector<const BasicBlock*> Preds(pred_begin(I->getParent()),
121 pred_end(I->getParent()));
122 // Loop over all of the incoming values, make sure that there are
123 // predecessors for each one...
125 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
126 const BasicBlock *BB = PN->getIncomingBlock(i);
127 std::vector<const BasicBlock*>::iterator PI =
128 find(Preds.begin(), Preds.end(), BB);
129 Assert2(PI != Preds.end(), "PHI node has entry for basic block that"
130 " is not a predecessor!", PN, BB);
131 if (PI != Preds.end()) Preds.erase(PI);
134 // There should be no entries left in the predecessor list...
135 for (std::vector<const BasicBlock*>::iterator I = Preds.begin(),
136 E = Preds.end(); I != E; ++I)
137 Assert2(0, "PHI node does not have entry for a predecessor basic block!",
140 // Check that non-phi nodes are not self referential...
141 for (Value::use_const_iterator UI = I->use_begin(), UE = I->use_end();
143 Assert1(*UI != (const User*)I,
144 "Only PHI nodes may reference their own value!", I);
151 // verifyBasicBlock - Verify that a basic block is well formed...
153 static bool verifyBasicBlock(const BasicBlock *BB) {
155 Assert1(BB->getTerminator(), "Basic Block does not have terminator!\n", BB);
157 // Verify all instructions, except the terminator...
158 Broken |= reduce_apply_bool(BB->begin(), BB->end()-1, verifyInstruction);
162 // verifySymbolTable - Verify that a method or module symbol table is ok
164 static bool verifySymbolTable(const SymbolTable *ST) {
165 if (ST == 0) return false;
168 // Loop over all of the types in the symbol table...
169 for (SymbolTable::const_iterator TI = ST->begin(), TE = ST->end();
171 for (SymbolTable::type_const_iterator I = TI->second.begin(),
172 E = TI->second.end(); I != E; ++I) {
173 Value *V = I->second;
175 // Check that there are no void typed values in the symbol table. Values
176 // with a void type cannot be put into symbol tables because they cannot
178 Assert1(V->getType() != Type::VoidTy,
179 "Values with void type are not allowed to have names!\n", V);
185 // verifyMethod - Verify that a method is ok. Return true if not so that
186 // verifyModule and direct clients of the verifyMethod function are correctly
189 bool verifyMethod(const Function *F) {
190 if (F->isExternal()) return false; // Can happen if called by verifyModule
191 bool Broken = verifySymbolTable(F->getSymbolTable());
193 Assert1(!F->isExternal() || F->hasExternalLinkage(),
194 "Function cannot be an 'internal' 'declare'ation!", F);
196 const BasicBlock *Entry = F->getEntryNode();
197 Assert1(pred_begin(Entry) == pred_end(Entry),
198 "Entry block to method must not have predecessors!", Entry);
200 Broken |= reduce_apply_bool(F->begin(), F->end(), verifyBasicBlock);
205 namespace { // Anonymous namespace for class
206 struct VerifierPass : public MethodPass {
208 bool doInitialization(Module *M) {
209 verifySymbolTable(M->getSymbolTable());
212 bool runOnMethod(Function *F) { verifyMethod(F); return false; }
216 Pass *createVerifierPass() {
217 return new VerifierPass();
220 // verifyModule - Check a module for errors, printing messages on stderr.
221 // Return true if the module is corrupt.
223 bool verifyModule(const Module *M) {
224 return verifySymbolTable(M->getSymbolTable()) |
225 reduce_apply_bool(M->begin(), M->end(), verifyMethod);