1*67e74705SXin Li // RUN: %clang_cc1 -fsyntax-only -verify -std=c++1y %s
2*67e74705SXin Li
3*67e74705SXin Li // expected-no-diagnostics
4*67e74705SXin Li
5*67e74705SXin Li // C++11 [basic.link]p6:
6*67e74705SXin Li // The name of a function declared in block scope and the name
7*67e74705SXin Li // of a variable declared by a block scope extern declaration
8*67e74705SXin Li // have linkage. If there is a visible declaration of an entity
9*67e74705SXin Li // with linkage having the same name and type, ignoring entities
10*67e74705SXin Li // declared outside the innermost enclosing namespace scope, the
11*67e74705SXin Li // block scope declaration declares that same entity and
12*67e74705SXin Li // receives the linkage of the previous declaration.
13*67e74705SXin Li
14*67e74705SXin Li extern int same_entity;
get1()15*67e74705SXin Li constexpr int *get1() {
16*67e74705SXin Li int same_entity = 0; // not the same entity
17*67e74705SXin Li {
18*67e74705SXin Li extern int same_entity;
19*67e74705SXin Li return &same_entity;
20*67e74705SXin Li }
21*67e74705SXin Li }
22*67e74705SXin Li static_assert(get1() == &same_entity, "failed to find previous decl");
23*67e74705SXin Li
24*67e74705SXin Li static int same_entity_2[3];
get2()25*67e74705SXin Li constexpr int *get2() {
26*67e74705SXin Li // This is a redeclaration of the same entity, even though it doesn't
27*67e74705SXin Li // inherit the type of the prior declaration.
28*67e74705SXin Li extern int same_entity_2[];
29*67e74705SXin Li return same_entity_2;
30*67e74705SXin Li }
31*67e74705SXin Li static_assert(get2() == same_entity_2, "failed to find previous decl");
32*67e74705SXin Li
33*67e74705SXin Li static int different_entities;
get3()34*67e74705SXin Li constexpr int *get3() {
35*67e74705SXin Li int different_entities = 0;
36*67e74705SXin Li {
37*67e74705SXin Li // FIXME: This is not a redeclaration of the prior entity, because
38*67e74705SXin Li // it is not visible here. Under DR426, this is ill-formed, and without
39*67e74705SXin Li // it, the static_assert below should fail.
40*67e74705SXin Li extern int different_entities;
41*67e74705SXin Li return &different_entities;
42*67e74705SXin Li }
43*67e74705SXin Li }
44*67e74705SXin Li static_assert(get3() == &different_entities, "failed to find previous decl");
45