c++: Only emit exported GMF usings [PR114600]

A typo in r14-6978 made us emit too many things. This ensures that we
don't emit using-declarations from the GMF that we don't need to.

	PR c++/114600

gcc/cp/ChangeLog:

	* module.cc (depset::hash::add_binding_entity): Require both
	WMB_Using and WMB_Export for GMF entities.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/using-14.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Co-authored-by: Patrick Palka <ppalka@redhat.com>

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 001430a4a8fe10c513f9eb703486a2b22b11a3b4..d94d8ff4df999969e8ff339da5fbd7e8a9568248 100644 (file)
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -13090,7 +13090,7 @@ depset::hash::add_binding_entity (tree decl, WMB_Flags flags, void *data_)
        inner = DECL_TEMPLATE_RESULT (inner);
 
       if ((!DECL_LANG_SPECIFIC (inner) || !DECL_MODULE_PURVIEW_P (inner))
-         && !(flags & (WMB_Using | WMB_Export)))
+         && !((flags & WMB_Using) && (flags & WMB_Export)))
        /* Ignore global module fragment entities unless explicitly
           exported with a using declaration.  */
        return false;

diff --git a/gcc/testsuite/g++.dg/modules/using-14.C b/gcc/testsuite/g++.dg/modules/using-14.C
new file mode 100644 (file)
index 0000000..0e15a95
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/using-14.C
@@ -0,0 +1,14 @@
+// PR c++/114600
+// { dg-additional-options "-fmodules-ts -Wno-global-module -fdump-lang-module" }
+// { dg-module-cmi M }
+
+module;
+namespace std {
+  template<class T> struct A { int n; };
+  template<class T> A<T> f();
+  namespace __swappable_details { using std::f; }
+}
+export module M;
+
+// The whole GMF should be discarded here
+// { dg-final { scan-lang-dump "Wrote 0 clusters" module } }