clang/test/Modules/cxx20-10-2-ex5.cpp

   1 // Based on C++20 10.2 example 5.
   2
   3 // RUN: rm -rf %t
   4 // RUN: mkdir -p %t
   5 // RUN: split-file %s %t
   6
   7 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std-10-2-ex5-tu1.cpp \
   8 // RUN:  -o  %t/M.pcm
   9
  10 // RUN: %clang_cc1 -std=c++20 -emit-obj %t/std-10-2-ex5-tu2.cpp \
  11 // RUN:  -fmodule-file=M=%t/M.pcm -o  %t/tu-2.o
  12
  13 // RUN: %clang_cc1 -std=c++20 -emit-obj %t/std-10-2-ex5-tu3.cpp \
  14 // RUN:  -fmodule-file=M=%t/M.pcm -verify -o %t/main.o
  15
  16 //--- std-10-2-ex5-tu1.cpp
  17 export module M;
  18 export struct X {
  19   static void f();
  20   struct Y {};
  21 };
  22 namespace {
  23 struct S {};
  24 } // namespace
  25 export void f(S); // OK
  26 struct T {};
  27 export T id(T);  // OK
  28 export struct A; // A exported as incomplete
  29
  30 export auto rootFinder(double a) {
  31   return [=](double x) { return (x + a / x) / 2; };
  32 }
  33 export const int n = 5; // OK, n has external linkage
  34
  35 //--- std-10-2-ex5-tu2.cpp
  36
  37 module M;
  38 struct A {
  39   int value;
  40 };
  41
  42 //--- std-10-2-ex5-tu3.cpp
  43
  44 import M;
  45
  46 int main() {
  47   X::f();                 // OK, X is exported and definition of X is reachable
  48   X::Y y;                 // OK, X::Y is exported as a complete type
  49   auto f = rootFinder(2); // OK
  50                           // error: A is incomplete
  51   return A{45}.value;     // expected-error {{invalid use of incomplete type 'A'}}
  52                           // expected-error@-1 {{member access into incomplete type 'A'}}
  53                           // expected-note@std-10-2-ex5-tu1.cpp:12 2{{forward declaration of 'A'}}
  54 }