Implement P1094R2 (nested inline namespaces)

As approved for the Working Paper in San Diego, support annotating
inline namespaces with 'inline'.

Change-Id: I51a654e11ffb475bf27cccb2458768151619e384
llvm-svn: 346677

1 files changed, 51 insertions, 0 deletions

diff --git a/clang/test/Parser/cxx2a-inline-nested-namespace-definition.cpp b/clang/test/Parser/cxx2a-inline-nested-namespace-definition.cpp
new file mode 100644
index 00000000000..8e603d24c01
--- /dev/null
+++ b/clang/test/Parser/cxx2a-inline-nested-namespace-definition.cpp
@@ -0,0 +1,51 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++14
+// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++17
+// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++2a -Wc++17-compat
+
+namespace inline foo1::foo2::foo3 { // expected-error {{expected identifier or '{'}} expected-error {{use of undeclared identifier 'foo1'}}
+}
+
+inline namespace foo4::foo5::foo6 { // expected-error {{nested namespace definition cannot be 'inline'}}}
+}
+
+#if __cplusplus <= 201402L
+// expected-warning@+7 {{nested namespace definition is a C++17 extension; define each namespace separately}}
+// expected-warning@+6 {{inline nested namespace definition is a C++2a extension}}
+#elif __cplusplus <= 201703L
+// expected-warning@+4 {{inline nested namespace definition is a C++2a extension}}
+#else
+// expected-warning@+2 {{inline nested namespace definition is incompatible with C++ standards before C++2a}}
+#endif
+namespace valid1::valid2::inline valid3::inline valid4::valid5{}
+// expected-note@-1 2 {{previous definition is here}}
+
+#if __cplusplus <= 201402L
+// expected-warning@+3 {{nested namespace definition is a C++17 extension; define each namespace separately}}
+#endif
+//expected-warning@+1 2 {{inline namespace reopened as a non-inline namespace}}
+namespace valid1::valid2::valid3::valid4::valid5{}
+
+#if __cplusplus <= 201402L
+// expected-warning@+7 {{nested namespace definition is a C++17 extension; define each namespace separately}}
+// expected-warning@+6 {{inline nested namespace definition is a C++2a extension}}
+#elif __cplusplus <= 201703L
+// expected-warning@+4 {{inline nested namespace definition is a C++2a extension}}
+#else
+// expected-warning@+2 {{inline nested namespace definition is incompatible with C++ standards before C++2a}}
+#endif
+namespace valid1::valid2::inline valid3::inline valid4::valid5{}
+// expected-note@-1 2 {{previous definition is here}}
+
+namespace valid1 {
+  namespace valid2 {
+//expected-warning@+1 {{inline namespace reopened as a non-inline namespace}}
+    namespace valid3 {
+//expected-warning@+1 {{inline namespace reopened as a non-inline namespace}}
+      namespace valid4 {
+        namespace valid5 {
+        }
+      }
+    }
+  }
+}
+