Rough out a new c'tor for the AttrBuilder class.

This c'tor takes the AttributeSet class as the parameter. It will eventually
grab the attributes from the specified index and create a new attribute builder
with those attributes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171712 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/AttributeImpl.h b/lib/IR/AttributeImpl.h
index a2a5218..7bb666a 100644
--- a/lib/IR/AttributeImpl.h
+++ b/lib/IR/AttributeImpl.h
@@ -39,9 +39,7 @@
                 ArrayRef<Constant*> values);
   AttributeImpl(LLVMContext &C, StringRef data);
 
-  ArrayRef<Constant*> getValues() const {
-    return Vals;
-  }
+  ArrayRef<Constant*> getValues() const { return Vals; }
 
   bool hasAttribute(Attribute::AttrKind A) const;
 
diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 117b510..bef7a6c 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -241,6 +241,26 @@
 // AttrBuilder Method Implementations
 //===----------------------------------------------------------------------===//
 
+AttrBuilder::AttrBuilder(AttributeSet AS, unsigned Idx)
+  : Alignment(0), StackAlignment(0) {
+  AttributeSetImpl *pImpl = AS.AttrList;
+  if (!pImpl) return;
+
+  ArrayRef<AttributeWithIndex> AttrList = pImpl->getAttributes();
+  const AttributeWithIndex *AWI = 0;
+  for (unsigned I = 0, E = AttrList.size(); I != E; ++I)
+    if (AttrList[I].Index == Idx) {
+      AWI = &AttrList[I];
+      break;
+    }
+
+  assert(AWI && "Cannot find index in attribute set!");
+
+  /// FIXME: This will be modified in the future. Basically, the
+  /// AttributeWithIndex class will contain the
+
+}
+
 void AttrBuilder::clear() {
   Attrs.clear();
   Alignment = StackAlignment = 0;