add an accessor to provide more checking


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23289 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/DAGISelEmitter.h b/utils/TableGen/DAGISelEmitter.h
index 65c7e70..9c84843 100644
--- a/utils/TableGen/DAGISelEmitter.h
+++ b/utils/TableGen/DAGISelEmitter.h
@@ -235,6 +235,10 @@
     const std::vector<TreePatternNode*> &getTrees() const { return Trees; }
     unsigned getNumTrees() const { return Trees.size(); }
     TreePatternNode *getTree(unsigned i) const { return Trees[i]; }
+    TreePatternNode *getOnlyTree() const {
+      assert(Trees.size() == 1 && "Doesn't have exactly one pattern!");
+      return Trees[0];
+    }
         
     /// getRecord - Return the actual TableGen record corresponding to this
     /// pattern.