Rewrite the function-local validation logic for MDNodes (most of r91708).

Among other benefits, this doesn't leak the SmallPtrSet, has the verifier
code in the verifier pass, actually does the verification at the end,
and is considerably simpler.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92217 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 39 insertions, 46 deletions

diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp
index 01b47d6767..c1213a3d3a 100644
--- a/lib/VMCore/Metadata.cpp
+++ b/lib/VMCore/Metadata.cpp
@@ -188,46 +188,6 @@ void MDNode::replaceElement(Value *From, Value *To) {
   }
 }
 
-// getLocalFunction - Return false if MDNode's recursive function-localness is
-// invalid (local to more than one function).  Return true otherwise. If MDNode
-// has one function to which it is local, set LocalFunction to that function.
-bool MDNode::getLocalFunction(Function *LocalFunction,
-                              SmallPtrSet<MDNode *, 32> *VisitedMDNodes) {
-  if (!isFunctionLocal())
-    return true;
-    
-  if (!VisitedMDNodes)
-    VisitedMDNodes = new SmallPtrSet<MDNode *, 32>();
-    
-  if (!VisitedMDNodes->insert(this))
-    // MDNode has already been visited, nothing to do.
-    return true;
-
-  for (unsigned i = 0, e = getNumElements(); i != e; ++i) {
-    Value *V = getElement(i);
-    if (!V) continue;
-
-    Function *LocalFunctionTemp = NULL;
-    if (Instruction *I = dyn_cast<Instruction>(V))
-      LocalFunctionTemp = I->getParent()->getParent();
-    else if (MDNode *MD = dyn_cast<MDNode>(V))
-      if (!MD->getLocalFunction(LocalFunctionTemp, VisitedMDNodes))
-        // This MDNode's operand is function-locally invalid or local to a
-        // different function.
-        return false;
-
-    if (LocalFunctionTemp) {
-      if (!LocalFunction)
-        LocalFunction = LocalFunctionTemp;
-      else if (LocalFunction != LocalFunctionTemp)
-        // This MDNode contains operands that are local to different functions.
-        return false;
-    }
-  }
-    
-  return true;
-}
-
 //===----------------------------------------------------------------------===//
 // NamedMDNode implementation.
 //
diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index a1b89dedea..b7e87711ae 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -329,6 +329,8 @@ namespace {
                           int VT, unsigned ArgNo, std::string &Suffix);
     void VerifyIntrinsicPrototype(Intrinsic::ID ID, Function *F,
                                   unsigned RetNum, unsigned ParamNum, ...);
+    void VerifyFunctionLocalMetadata(MDNode *N, Function *F,
+                                     SmallPtrSet<MDNode *, 32> &Visited);
     void VerifyParameterAttrs(Attributes Attrs, const Type *Ty,
                               bool isReturnValue, const Value *V);
     void VerifyFunctionAttrs(const FunctionType *FT, const AttrListPtr &Attrs,
@@ -1526,6 +1528,38 @@ void Verifier::VerifyType(const Type *Ty) {
   }
 }
 
+/// VerifyFunctionLocalMetadata - Verify that the specified MDNode is local to
+/// specified Function.
+void Verifier::VerifyFunctionLocalMetadata(MDNode *N, Function *F,
+                                           SmallPtrSet<MDNode *, 32> &Visited) {
+  assert(N->isFunctionLocal() && "Should only be called on function-local MD");
+
+  // Only visit each node once.
+  if (!Visited.insert(N))
+    return;
+  
+  for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
+    Value *V = N->getElement(i);
+    if (!V) continue;
+    
+    Function *ActualF = 0;
+    if (Instruction *I = dyn_cast<Instruction>(V))
+      ActualF = I->getParent()->getParent();
+    else if (BasicBlock *BB = dyn_cast<BasicBlock>(V))
+      ActualF = BB->getParent();
+    else if (Argument *A = dyn_cast<Argument>(V))
+      ActualF = A->getParent();
+    else if (MDNode *MD = dyn_cast<MDNode>(V))
+      if (MD->isFunctionLocal())
+        VerifyFunctionLocalMetadata(MD, F, Visited);
+
+    // If this was an instruction, bb, or argument, verify that it is in the
+    // function that we expect.
+    Assert1(ActualF == 0 || ActualF == F,
+            "function-local metadata used in wrong function", N);
+  }
+}
+
 // Flags used by TableGen to mark intrinsic parameters with the
 // LLVMExtendedElementVectorType and LLVMTruncatedElementVectorType classes.
 static const unsigned ExtendedElementVectorType = 0x40000000;
@@ -1542,14 +1576,13 @@ void Verifier::visitIntrinsicFunctionCall(Intrinsic::ID ID, CallInst &CI) {
 #include "llvm/Intrinsics.gen"
 #undef GET_INTRINSIC_VERIFIER
 
+  // If the intrinsic takes MDNode arguments, verify that they are either global
+  // or are local to *this* function.
   for (unsigned i = 0, e = CI.getNumOperands(); i != e; ++i)
     if (MDNode *MD = dyn_cast<MDNode>(CI.getOperand(i))) {
-      Function* LocalFunction = NULL;
-      Assert1(MD && MD->getLocalFunction(LocalFunction),
-              "invalid function-local metadata", &CI);
-      if (LocalFunction)
-        Assert1(LocalFunction == CI.getParent()->getParent(),
-                "function-local metadata used in wrong function", &CI);
+      if (!MD->isFunctionLocal()) continue;
+      SmallPtrSet<MDNode *, 32> Visited;
+      VerifyFunctionLocalMetadata(MD, CI.getParent()->getParent(), Visited);
     }
 
   switch (ID) {