Add driver arguments -ftemplate-depth=N and -fconstexpr-depth=N, with the same
semantics and defaults as the corresponding g++ arguments. The historical g++
argument -ftemplate-depth-N is kept for compatibility, but modern g++ versions
no longer document that option.
Add -cc1 argument -fconstexpr-depth N to implement the corresponding
functionality.
The -ftemplate-depth=N part of this fixes PR9890.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145045 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/constexpr-depth.cpp b/test/SemaCXX/constexpr-depth.cpp
new file mode 100644
index 0000000..b8ae668
--- /dev/null
+++ b/test/SemaCXX/constexpr-depth.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s -DMAX=128 -fconstexpr-depth 128
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s -DMAX=1 -fconstexpr-depth 1
+// RUN: %clang -std=c++11 -fsyntax-only -Xclang -verify %s -DMAX=10 -fconstexpr-depth=10
+
+constexpr int depth(int n) { return n > 1 ? depth(n-1) : 0; }
+
+constexpr int kBad = depth(MAX + 1); // expected-error {{must be initialized by a constant expression}}
+constexpr int kGood = depth(MAX);