* Update to work with Megapatch

* Add two new checks:
  * 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2773 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 153 insertions, 105 deletions

diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index d09678c..605764a 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -19,7 +19,8 @@
 //    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.
-//  . All basic blocks should only end with terminator insts, not contain them
+//  * 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.
@@ -43,7 +44,6 @@
 #include "llvm/iTerminators.h"
 #include "llvm/iOther.h"
 #include "llvm/iMemory.h"
-#include "llvm/Argument.h"
 #include "llvm/SymbolTable.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/InstVisitor.h"
@@ -59,21 +59,21 @@ namespace {  // Anonymous namespace for class
 
     virtual const char *getPassName() const { return "Module Verifier"; }
 
-    bool doInitialization(Module *M) {
-      verifySymbolTable(M->getSymbolTable());
+    bool doInitialization(Module &M) {
+      verifySymbolTable(M.getSymbolTable());
       return false;
     }
 
-    bool runOnFunction(Function *F) {
+    bool runOnFunction(Function &F) {
       visit(F);
       return false;
     }
 
-    bool doFinalization(Module *M) {
+    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));
+      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) {
         cerr << "Broken module found, compilation aborted!\n";
@@ -88,25 +88,30 @@ namespace {  // Anonymous namespace for class
 
     // 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 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 *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 (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;
     }
   };
@@ -119,6 +124,10 @@ namespace {  // Anonymous namespace for class
   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
@@ -143,30 +152,31 @@ void Verifier::verifySymbolTable(SymbolTable *ST) {
 
 // visitFunction - Verify that a function is ok.
 //
-void Verifier::visitFunction(Function *F) {
-  if (F->isExternal()) return;
+void Verifier::visitFunction(Function &F) {
+  if (F.isExternal()) return;
 
-  verifySymbolTable(F->getSymbolTable());
+  verifySymbolTable(F.getSymbolTable());
 
   // Check function arguments...
-  const FunctionType *FT = F->getFunctionType();
-  const Function::ArgumentListType &ArgList = F->getArgumentList();
+  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() == ArgList.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);
+          &F, FT);
 
   // Check that the argument values match the function type for this function...
-  if (FT->getParamTypes().size() == ArgList.size()) {
-    for (unsigned i = 0, e = ArgList.size(); i != e; ++i)
-      Assert2(ArgList[i]->getType() == FT->getParamType(i),
+  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!",
-              ArgList[i], FT->getParamType(i));
+              I, FT->getParamType(i));
   }
 
   // Check the entry node
-  BasicBlock *Entry = F->getEntryNode();
+  BasicBlock *Entry = &F.getEntryNode();
   Assert1(pred_begin(Entry) == pred_end(Entry),
           "Entry block to function must not have predecessors!", Entry);
 }
@@ -174,43 +184,60 @@ void Verifier::visitFunction(Function *F) {
 
 // verifyBasicBlock - Verify that a basic block is well formed...
 //
-void Verifier::visitBasicBlock(BasicBlock *BB) {
-  Assert1(BB->getTerminator(), "Basic Block does not have terminator!", BB);
-
-  // Check that the terminator is ok as well...
-  if (isa<ReturnInst>(BB->getTerminator())) {
-    Instruction *I = BB->getTerminator();
-    Function *F = I->getParent()->getParent();
-    if (I->getNumOperands() == 0)
-      Assert1(F->getReturnType() == Type::VoidTy,
-              "Function returns no value, but ret instruction found that does!",
-              I);
-    else
-      Assert2(F->getReturnType() == I->getOperand(0)->getType(),
-              "Function return type does not match operand "
-              "type of return inst!", I, F->getReturnType());
-  }
+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());
+}
+
+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) {
-  std::vector<BasicBlock*> Preds(pred_begin(PN->getParent()),
-                                 pred_end(PN->getParent()));
+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) {
+  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(),
+    Assert2(PN.getType() == PN.getIncomingValue(i)->getType(),
             "PHI node argument type does not agree with PHI node type!",
-            PN, PN->getIncomingValue(i));
+            &PN, PN.getIncomingValue(i));
 
-    BasicBlock *BB = PN->getIncomingBlock(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);
+            " is not a predecessor!", &PN, BB);
     Preds.erase(PI);
   }
   
@@ -218,101 +245,122 @@ void Verifier::visitPHINode(PHINode *PN) {
   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);
+            &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);
-  PointerType *FPTy = cast<PointerType>(CI->getOperand(0)->getType());
+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);
+          "Called function is not pointer to function type!", &CI);
 
-  FunctionType *FTy = cast<FunctionType>(FPTy->getElementType());
+  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);
+    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);
+    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),
+    Assert2(CI.getOperand(i+1)->getType() == FTy->getParamType(i),
             "Call parameter type does not match function signature!",
-            CI->getOperand(i+1), FTy->getParamType(i));
+            CI.getOperand(i+1), FTy->getParamType(i));
 }
 
 // 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(),
+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));
+          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);
+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);
+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);
+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 a non-terminator instruction is well formed.
 //
-void Verifier::visitInstruction(Instruction *I) {
-  assert(I->getParent() && "Instruction not embedded in basic block!");
+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();
+  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);
+            " 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();
+    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);
+      Assert1(*UI != (User*)&I,
+              "Only PHI nodes may reference their own value!", &I);
   }
 
-  Assert1(I->getType() != Type::VoidTy || !I->hasName(),
-          "Instruction has a name, but provides a void value!", I);
+  Assert1(I.getType() != Type::VoidTy || !I.hasName(),
+          "Instruction has a name, but provides a void value!", &I);
 }
 
 
@@ -324,17 +372,17 @@ Pass *createVerifierPass() {
   return new Verifier();
 }
 
-bool verifyFunction(const Function *F) {
+bool verifyFunction(const Function &F) {
   Verifier V;
-  V.visit((Function*)F);
+  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) {
+bool verifyModule(const Module &M) {
   Verifier V;
-  V.run((Module*)M);
+  V.run((Module&)M);
   return V.Broken;
 }