[Parser] Warn when ScopeDepthOrObjCQuals overflows

Before when the overflow occured an assertion was triggered. Now check
whether the maximum has been reached and warn properly.

This patch fixes the original submission of PR19607.

Differential Revision: https://reviews.llvm.org/D63975

1 files changed, 55 insertions, 0 deletions

diff --git a/clang/test/Parser/nested_lambda_overflow.cpp b/clang/test/Parser/nested_lambda_overflow.cpp
new file mode 100644
index 00000000000..afaa9dca635
--- /dev/null
+++ b/clang/test/Parser/nested_lambda_overflow.cpp
@@ -0,0 +1,55 @@
+// RUN: %clang %s -fsyntax-only -fbracket-depth=512
+// RUN: not %clang %s -fsyntax-only -fbracket-depth=512 -DFAIL 2>&1 | FileCheck %s
+
+template <class T> int foo(T &&t);
+
+void bar(int x = foo(
+
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+
+[](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo([](int x = foo(
+
+#ifdef FAIL
+[](int x = foo(
+#endif
+
+[](int x = foo(1)){}
+
+#ifdef FAIL
+)){}
+#endif
+
+)){})){})){})){})){})){}
+
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+)){})){})){})){})){})){})){})){}
+));
+
+// CHECK: fatal error: function scope depth exceeded maximum of 127