1 //===-- Verifier.cpp - Implement the Module Verifier -------------*- C++ -*-==//
3 // This file defines the method 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 method 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 // . Method's cannot take a void typed parameter
27 // . Verify that a method'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 // . All other things that are tested by asserts spread about the code...
32 //===----------------------------------------------------------------------===//
34 #include "llvm/Analysis/Verifier.h"
35 #include "llvm/Assembly/Writer.h"
36 #include "llvm/Pass.h"
37 #include "llvm/Method.h"
38 #include "llvm/Module.h"
39 #include "llvm/BasicBlock.h"
40 #include "llvm/Type.h"
41 #include "llvm/iPHINode.h"
42 #include "llvm/SymbolTable.h"
43 #include "llvm/Support/CFG.h"
44 #include "Support/STLExtras.h"
48 #define t(x) (1 << (unsigned)Type::x)
49 #define SignedIntegralTypes (t(SByteTyID) | t(ShortTyID) | \
50 t(IntTyID) | t(LongTyID))
51 static long UnsignedIntegralTypes = t(UByteTyID) | t(UShortTyID) |
52 t(UIntTyID) | t(ULongTyID);
53 static const long FloatingPointTypes = t(FloatTyID) | t(DoubleTyID);
55 static const long IntegralTypes = SignedIntegralTypes | UnsignedIntegralTypes;
57 static long ValidTypes[Type::FirstDerivedTyID] = {
58 [(unsigned)Instruction::UnaryOps::Not] t(BoolTyID),
59 //[Instruction::UnaryOps::Add] = IntegralTypes,
60 // [Instruction::Sub] = IntegralTypes,
65 // CheckFailed - A check failed, so print out the condition and the message that
66 // failed. This provides a nice place to put a breakpoint if you want to see
67 // why something is not correct.
69 static inline void CheckFailed(const char *Cond, const std::string &Message,
70 const Value *V1 = 0, const Value *V2 = 0) {
71 std::cerr << Message << "\n";
72 if (V1) std::cerr << V1 << "\n";
73 if (V2) std::cerr << V2 << "\n";
76 // Assert - We know that cond should be true, if not print an error message.
77 #define Assert(C, M) \
78 do { if (!(C)) { CheckFailed(#C, M); Broken = true; } } while (0)
79 #define Assert1(C, M, V1) \
80 do { if (!(C)) { CheckFailed(#C, M, V1); Broken = true; } } while (0)
81 #define Assert2(C, M, V1, V2) \
82 do { if (!(C)) { CheckFailed(#C, M, V1, V2); Broken = true; } } while (0)
85 // verifyInstruction - Verify that a non-terminator instruction is well formed.
87 static bool verifyInstruction(const Instruction *I) {
89 assert(I->getParent() && "Instruction not embedded in basic block!");
90 Assert1(!isa<TerminatorInst>(I),
91 "Terminator instruction found embedded in basic block!\n", I);
93 // Check that all uses of the instruction, if they are instructions
94 // themselves, actually have parent basic blocks.
96 for (User::use_const_iterator UI = I->use_begin(), UE = I->use_end();
98 if (Instruction *Used = dyn_cast<Instruction>(*UI))
99 Assert2(Used->getParent() != 0, "Instruction referencing instruction not"
100 " embeded in a basic block!", I, Used);
103 // Check that PHI nodes look ok
104 if (const PHINode *PN = dyn_cast<PHINode>(I)) {
105 std::vector<const BasicBlock*> Preds(pred_begin(I->getParent()),
106 pred_end(I->getParent()));
107 // Loop over all of the incoming values, make sure that there are
108 // predecessors for each one...
110 for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
111 const BasicBlock *BB = PN->getIncomingBlock(i);
112 std::vector<const BasicBlock*>::iterator PI =
113 find(Preds.begin(), Preds.end(), BB);
114 Assert2(PI != Preds.end(), "PHI node has entry for basic block that"
115 " is not a predecessor!", PN, BB);
116 if (PI != Preds.end()) Preds.erase(PI);
119 // There should be no entries left in the predecessor list...
120 for (std::vector<const BasicBlock*>::iterator I = Preds.begin(),
121 E = Preds.end(); I != E; ++I)
122 Assert2(0, "PHI node does not have entry for a predecessor basic block!",
125 // Check that non-phi nodes are not self referential...
126 for (Value::use_const_iterator UI = I->use_begin(), UE = I->use_end();
128 Assert1(*UI != (const User*)I,
129 "Only PHI nodes may reference their own value!", I);
136 // verifyBasicBlock - Verify that a basic block is well formed...
138 static bool verifyBasicBlock(const BasicBlock *BB) {
140 Assert1(BB->getTerminator(), "Basic Block does not have terminator!\n", BB);
142 // Verify all instructions, except the terminator...
143 Broken |= reduce_apply_bool(BB->begin(), BB->end()-1, verifyInstruction);
147 // verifySymbolTable - Verify that a method or module symbol table is ok
149 static bool verifySymbolTable(const SymbolTable *ST) {
150 if (ST == 0) return false;
153 // Loop over all of the types in the symbol table...
154 for (SymbolTable::const_iterator TI = ST->begin(), TE = ST->end();
156 for (SymbolTable::type_const_iterator I = TI->second.begin(),
157 E = TI->second.end(); I != E; ++I) {
158 Value *V = I->second;
160 // Check that there are no void typed values in the symbol table. Values
161 // with a void type cannot be put into symbol tables because they cannot
163 Assert1(V->getType() != Type::VoidTy,
164 "Values with void type are not allowed to have names!\n", V);
170 // verifyMethod - Verify that a method is ok. Return true if not so that
171 // verifyModule and direct clients of the verifyMethod function are correctly
174 bool verifyMethod(const Method *M) {
175 if (M->isExternal()) return false; // Can happen if called by verifyModule
177 bool Broken = verifySymbolTable(M->getSymbolTable());
178 const BasicBlock *Entry = M->front();
179 Assert1(pred_begin(Entry) == pred_end(Entry),
180 "Entry block to method must not have predecessors!", Entry);
182 Broken |= reduce_apply_bool(M->begin(), M->end(), verifyBasicBlock);
187 namespace { // Anonymous namespace for class
188 struct VerifierPass : public MethodPass {
190 bool doInitialization(Module *M) {
191 verifySymbolTable(M->getSymbolTable());
194 bool runOnMethod(Method *M) { verifyMethod(M); return false; }
198 Pass *createVerifierPass() {
199 return new VerifierPass();
202 // verifyModule - Check a module for errors, printing messages on stderr.
203 // Return true if the module is corrupt.
205 bool verifyModule(const Module *M) {
206 return verifySymbolTable(M->getSymbolTable()) |
207 reduce_apply_bool(M->begin(), M->end(), verifyMethod);