Implement __attribute__((internal_linkage)).

The attrubite is applicable to functions and variables and changes
the linkage of the subject to internal.

This is the same functionality as C-style "static", but applicable to
class methods; and the same as anonymouns namespaces, but can apply
to individual methods of a class.

Following the proposal in
http://lists.llvm.org/pipermail/cfe-dev/2015-October/045580.html

llvm-svn: 252648

1 files changed, 47 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/internal_linkage.cpp b/clang/test/SemaCXX/internal_linkage.cpp
new file mode 100644
index 00000000000..d5cc6767392
--- /dev/null
+++ b/clang/test/SemaCXX/internal_linkage.cpp
@@ -0,0 +1,47 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
+
+int f() __attribute__((internal_linkage));
+
+class A;
+class __attribute__((internal_linkage)) A {
+public:
+  int x __attribute__((internal_linkage)); // expected-warning{{'internal_linkage' attribute only applies to variables, functions and classes}}
+  static int y __attribute__((internal_linkage));
+  void f1() __attribute__((internal_linkage));
+  void f2() __attribute__((internal_linkage)) {}
+  static void f3() __attribute__((internal_linkage)) {}
+  void f4(); // expected-note{{previous definition is here}}
+  static int zz; // expected-note{{previous definition is here}}
+  A() __attribute__((internal_linkage)) {}
+  ~A() __attribute__((internal_linkage)) {}
+  A& operator=(const A&) __attribute__((internal_linkage)) { return *this; }
+  struct {
+    int z  __attribute__((internal_linkage)); // expected-warning{{'internal_linkage' attribute only applies to variables, functions and classes}}
+  };
+};
+
+__attribute__((internal_linkage)) void A::f4() {} // expected-error{{'internal_linkage' attribute does not appear on the first declaration of 'f4'}}
+
+__attribute__((internal_linkage)) int A::zz; // expected-error{{'internal_linkage' attribute does not appear on the first declaration of 'zz'}}
+
+namespace Z __attribute__((internal_linkage)) { // expected-warning{{'internal_linkage' attribute only applies to variables, functions and classes}}
+}
+
+__attribute__((internal_linkage("foo"))) int g() {} // expected-error{{'internal_linkage' attribute takes no arguments}}
+
+[[clang::internal_linkage]] int h() {}
+
+enum struct __attribute__((internal_linkage)) E { // expected-warning{{'internal_linkage' attribute only applies to variables, functions and classes}}
+  a = 1,
+  b = 2
+};
+
+int A::y;
+
+void A::f1() {
+}
+
+void g(int a [[clang::internal_linkage]]) { // expected-warning{{'internal_linkage' attribute only applies to variables, functions and classes}}
+  int x [[clang::internal_linkage]]; // expected-warning{{'internal_linkage' attribute on a non-static local variable is ignored}}
+  static int y [[clang::internal_linkage]];
+}