Introduce a new expression type, UnresolvedDeclRefExpr, that describes
dependent qualified-ids such as
Fibonacci<N - 1>::value
where N is a template parameter. These references are "unresolved"
because the name is dependent and, therefore, cannot be resolved to a
declaration node (as we would do for a DeclRefExpr or
QualifiedDeclRefExpr). UnresolvedDeclRefExprs instantiate to
DeclRefExprs, QualifiedDeclRefExprs, etc.
Also, be a bit more careful about keeping only a single set of
specializations for a class template, and instantiating from the
definition of that template rather than a previous declaration. In
general, we need a better solution for this for all TagDecls, because
it's too easy to accidentally look at a declaration that isn't the
definition.
We can now process a simple Fibonacci computation described as a
template metaprogram.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67308 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaTemplate/fibonacci.cpp b/test/SemaTemplate/fibonacci.cpp
new file mode 100644
index 0000000..b56d8cd
--- /dev/null
+++ b/test/SemaTemplate/fibonacci.cpp
@@ -0,0 +1,27 @@
+// RUN: clang -fsyntax-only %s
+
+// FIXME: The Fibonacci/FibonacciEval dance is here to work around our
+// inability to parse injected-class-name<template-argument-list>.
+template<unsigned I>
+struct FibonacciEval;
+
+template<unsigned I>
+struct Fibonacci {
+ enum { value = FibonacciEval<I-1>::value + FibonacciEval<I-2>::value };
+};
+
+template<unsigned I>
+struct FibonacciEval {
+ enum { value = Fibonacci<I>::value };
+};
+
+template<> struct Fibonacci<0> {
+ enum { value = 0 };
+};
+
+template<> struct Fibonacci<1> {
+ enum { value = 1 };
+};
+
+int array5[Fibonacci<5>::value == 5? 1 : -1];
+int array10[Fibonacci<10>::value == 55? 1 : -1];