xref: /aosp_15_r20/external/clang/test/Modules/redecl-templates.cpp (revision 67e74705e28f6214e480b399dd47ea732279e315)
1*67e74705SXin Li // RUN: rm -rf %t
2*67e74705SXin Li // RUN: %clang_cc1 -x c++ -I %S/Inputs/redecl-templates %s -verify -std=c++14
3*67e74705SXin Li // RUN: %clang_cc1 -x c++ -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -I %S/Inputs/redecl-templates %s -verify -std=c++14
4*67e74705SXin Li // expected-no-diagnostics
5*67e74705SXin Li 
6*67e74705SXin Li template<int N> struct A {};
7*67e74705SXin Li template<int N> using X = A<N>;
8*67e74705SXin Li 
f()9*67e74705SXin Li template<int N> constexpr void f() {}
g()10*67e74705SXin Li template<int N> constexpr void g() { f<N>(); }
11*67e74705SXin Li 
12*67e74705SXin Li template<int N> extern int v;
13*67e74705SXin Li template<int N> int &w = v<N>;
14*67e74705SXin Li 
15*67e74705SXin Li #include "a.h"
16*67e74705SXin Li 
17*67e74705SXin Li // Be careful not to mention A here, that'll import the decls from "a.h".
18*67e74705SXin Li int g(X<1> *);
19*67e74705SXin Li X<1> *p = 0;
20*67e74705SXin Li 
21*67e74705SXin Li // This will implicitly instantiate A<1> if we haven't imported the explicit
22*67e74705SXin Li // specialization declaration from "a.h".
23*67e74705SXin Li int k = g(p);
24*67e74705SXin Li // Likewise for f and v.
h()25*67e74705SXin Li void h() { g<1>(); }
26*67e74705SXin Li int &x = w<1>;
27*67e74705SXin Li 
28*67e74705SXin Li // This is OK: we declared the explicit specialization before we triggered
29*67e74705SXin Li // instantiation of this specialization.
30*67e74705SXin Li template<> struct A<1> {};
f()31*67e74705SXin Li template<> constexpr void f<1>() {}
32*67e74705SXin Li template<> int v<1>;
33