add the 'alloc' metadata node to represent the size of offset of buffers pointed to by pointers.

This metadata can be attached to any instruction returning a pointer


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158660 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 38 insertions, 0 deletions

diff --git a/lib/VMCore/LLVMContext.cpp b/lib/VMCore/LLVMContext.cpp
index f07f0b3..a140543 100644
--- a/lib/VMCore/LLVMContext.cpp
+++ b/lib/VMCore/LLVMContext.cpp
@@ -53,6 +53,11 @@ LLVMContext::LLVMContext() : pImpl(new LLVMContextImpl(*this)) {
   unsigned RangeID = getMDKindID("range");
   assert(RangeID == MD_range && "range kind id drifted");
   (void)RangeID;
+
+  // Create the 'alloc' metadata kind.
+  unsigned AllocID = getMDKindID("alloc");
+  assert(AllocID == MD_alloc && "alloc kind id drifted");
+  (void)AllocID;
 }
 LLVMContext::~LLVMContext() { delete pImpl; }
 
diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 477b81d..2ca4854 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -1672,6 +1672,39 @@ void Verifier::visitInstruction(Instruction &I) {
     }
   }
 
+  if (MDNode *MD = I.getMetadata(LLVMContext::MD_alloc)) {
+    Assert1(I.getType()->isPointerTy(), "alloc requires a pointer result", &I);
+    Assert1(MD->getNumOperands() >= 1, "alloc takes at least one operand", &I);
+    Function *SizeFn = dyn_cast<Function>(MD->getOperand(0));
+    Function *OffsetFn = MD->getNumOperands() >= 2 ?
+                         dyn_cast_or_null<Function>(MD->getOperand(1)) : 0;
+    Assert1(SizeFn, "first parameter of alloc must be a function", &I);
+    Assert1(MD->getNumOperands() == 1 || !MD->getOperand(1) || OffsetFn,
+            "second parameter of alloc must be either a function or null", &I);
+    Assert1(SizeFn->onlyReadsMemory(),
+            "size function must be readonly/readnone", &I);
+    Assert1(!OffsetFn || OffsetFn->onlyReadsMemory(),
+            "offset function must be readonly/readnone", &I);
+    Assert1(SizeFn->getReturnType()->isIntegerTy(),
+            "size function must return an integer", &I);
+    Assert1(!OffsetFn || OffsetFn->getReturnType()->isIntegerTy(),
+            "offset function must return an integer", &I);
+
+    FunctionType *SizeFnTy = SizeFn->getFunctionType();
+    FunctionType *OffsetFnTy = OffsetFn ? OffsetFn->getFunctionType() : 0;
+    Assert1(SizeFnTy->getNumParams() == MD->getNumOperands()-2,
+            "size function number of parameters mismatch", &I);
+    Assert1(!OffsetFnTy || OffsetFnTy->getNumParams() == MD->getNumOperands()-2,
+            "offset function number of parameters mismatch", &I);
+    for (unsigned i = 0, e = SizeFnTy->getNumParams(); i != e; ++i) {
+      Assert1(SizeFnTy->getParamType(i) == MD->getOperand(i+2)->getType(),
+              "size function parameter type mismatch", &I);
+      if (OffsetFnTy)
+        Assert1(OffsetFnTy->getParamType(i) == MD->getOperand(i+2)->getType(),
+                "offset function parameter type mismatch", &I);
+    }
+  }
+
   MDNode *MD = I.getMetadata(LLVMContext::MD_range);
   Assert1(!MD || isa<LoadInst>(I), "Ranges are only for loads!", &I);