[libc++] Fix issue with std::map::find in Objective-C++ with modules

[ldionne]

Summary

This works around an issue with modules where Clang complains that
it doesn't know about coroutine_handle<> when trying to write very
basic code using std::map::find.

rdar://106813461

[ldionne]

Fix GCC CI

[Mordante]

LGTM modulo one nit.

libcxx/include/module.modulemap.in

1790

Please add a comment why this is not in alphabetic order.

[ldionne]

libcxx/include/module.modulemap.in

1790

Good suggestion, will add upon landing to avoid re-running CI.

libcxx/include/module.modulemap.in

module std [system] {
   module condition_variable {
     header "condition_variable"
     export *
 
     module __condition_variable {
       module condition_variable { private header "__condition_variable/condition_variable.h" }
     }
   }
-  module coroutine {
-    header "coroutine"
-    export compare
-    export *
-
-    module __coroutine {
-      module coroutine_handle           { private header "__coroutine/coroutine_handle.h" }
-      module coroutine_traits           { private header "__coroutine/coroutine_traits.h" }
-      module noop_coroutine_handle      { private header "__coroutine/noop_coroutine_handle.h" }
-      module trivial_awaitables         { private header "__coroutine/trivial_awaitables.h" }
-    }
-  }
   module deque {
     header "deque"
     export initializer_list
     export *
   }
   module exception {
     header "exception"
     export *

   module __node_handle       { private header "__node_handle"       export * }
   module __split_buffer      { private header "__split_buffer"      export * }
   module __std_mbstate_t     { private header "__std_mbstate_t.h"   export * }
   module __threading_support {         header "__threading_support" export * }
   module __tree              {         header "__tree"              export * }
   module __undef_macros      {         header "__undef_macros"      export * }
   module __verbose_abort     {         header "__verbose_abort"     export * }
 
+  // This one needs to appear after __tree to work around issues with modules in Objective-C++ mode.
+  module coroutine {
+    header "coroutine"
+    export compare
+    export *
+
+    module __coroutine {
+      module coroutine_handle           { private header "__coroutine/coroutine_handle.h" }
+      module coroutine_traits           { private header "__coroutine/coroutine_traits.h" }
+      module noop_coroutine_handle      { private header "__coroutine/noop_coroutine_handle.h" }
+      module trivial_awaitables         { private header "__coroutine/trivial_awaitables.h" }
+    }
+  }
+
   module experimental {
     requires cplusplus11
 
     module deque {
       header "experimental/deque"
       export *
     }
     module forward_list {

libcxx/test/libcxx/containers/associative/map/find.modules.compile.pass.mm

+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// Make sure that we don't get a compiler error when trying to use std::map::find
+// from Objective-C++. This happened in Objective-C++ mode with modules enabled (rdar://106813461).
+
+// REQUIRES: objective-c++
+
+#include <map>
+
+void f(std::map<int, int> const& map, int key) {
+    (void)map.find(key);
+}