c++: Fix OpenMP support with C++20 modules [PR119864]

In r15-2799-gf1bfba3a9b3f31, a new kind of global constructor was added.
Unfortunately this broke C++20 modules, as both the host and target
constructors were given the same mangled name.  This patch ensures that
only the host constructor gets the module name mangling for now, and
stops forcing the creation of the target constructor even when no such
initialization is required.

	PR c++/119864

gcc/cp/ChangeLog:

	* decl2.cc (start_objects): Only use module initialized for
	host.
	(c_parse_final_cleanups): Don't always create an OMP offload
	init function in modules.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/openmp-1.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jason Merrill <jason@redhat.com>

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index 15db1d657341dfeeae68bfc0d574a063c184b382..a08d173c0df5328a7606c686fd4ac4cf20fce0bc 100644 (file)
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -4186,7 +4186,11 @@ start_objects (bool initp, unsigned priority, bool has_body,
               bool omp_target = false)
 {
   bool default_init = initp && priority == DEFAULT_INIT_PRIORITY;
-  bool is_module_init = default_init && module_global_init_needed ();
+  /* FIXME: We may eventually want to treat OpenMP offload initializers
+     in modules specially as well.  */
+  bool is_module_init = (default_init
+                        && !omp_target
+                        && module_global_init_needed ());
   tree name = NULL_TREE;
 
   if (is_module_init)
@@ -5878,12 +5882,8 @@ c_parse_final_cleanups (void)
       if (static_init_fini_fns[true]->get_or_insert (DEFAULT_INIT_PRIORITY))
        has_module_inits = true;
 
-      if (flag_openmp)
-       {
-         if (!static_init_fini_fns[2 + true])
-           static_init_fini_fns[2 + true] = priority_map_t::create_ggc ();
-         static_init_fini_fns[2 + true]->get_or_insert (DEFAULT_INIT_PRIORITY);
-       }
+      /* FIXME: We need to work out what static constructors on OpenMP offload
+        target in modules will look like.  */
     }
 
   /* Generate initialization and destruction functions for all

diff --git a/gcc/testsuite/g++.dg/modules/openmp-1.C b/gcc/testsuite/g++.dg/modules/openmp-1.C
new file mode 100644 (file)
index 0000000..b5a30ad
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/openmp-1.C
@@ -0,0 +1,9 @@
+// PR c++/119864
+// { dg-do assemble }
+// { dg-additional-options "-fmodules -fopenmp" }
+// { dg-require-effective-target "fopenmp" }
+
+export module M;
+
+int foo();
+int x = foo();