[PATCH] c++/modules: Allow exporting const-qualified namespace-scope variables [PR99232]

[Nathaniel Shead]

Bootstrapped and regtested on x86_64-pc-linux-gnu. I don't have write
access.

-- >8 --

By [basic.link] p3.2.1, a non-template non-volatile const-qualified
variable is not necessarily internal linkage in a module declaration,
and rather may have module linkage (or external linkage if it is
exported, see p4.8).

        PR c++/99232

gcc/cp/ChangeLog:

        * decl.cc (grokvardecl): Don't mark variables attached to
        modules as internal.

gcc/testsuite/ChangeLog:

        * g++.dg/modules/pr99232_a.C: New test.
        * g++.dg/modules/pr99232_b.C: New test.

Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
---
 gcc/cp/decl.cc                           | 3 ++-
 gcc/testsuite/g++.dg/modules/pr99232_a.C | 8 ++++++++
 gcc/testsuite/g++.dg/modules/pr99232_b.C | 7 +++++++
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/modules/pr99232_a.C
 create mode 100644 gcc/testsuite/g++.dg/modules/pr99232_b.C

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index d2ed46b1453..173dd93ef5b 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -10992,7 +10992,8 @@ grokvardecl (tree type,
                            && (DECL_THIS_EXTERN (decl)
                                || ! constp
                                || volatilep
-                               || inlinep));
+                               || inlinep
+                               || module_attach_p ()));
       TREE_STATIC (decl) = ! DECL_EXTERNAL (decl);
     }
   /* Not at top level, only `static' makes a static definition.  */
diff --git a/gcc/testsuite/g++.dg/modules/pr99232_a.C 
b/gcc/testsuite/g++.dg/modules/pr99232_a.C
new file mode 100644
index 00000000000..33b3b783399
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/pr99232_a.C
@@ -0,0 +1,8 @@
+// PR c++/99232
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi pr99232 }
+
+export module pr99232;
+
+export const double lambda{ 1.3 };
+export constexpr int a = 42;
diff --git a/gcc/testsuite/g++.dg/modules/pr99232_b.C 
b/gcc/testsuite/g++.dg/modules/pr99232_b.C
new file mode 100644
index 00000000000..98f3c52a51c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/pr99232_b.C
@@ -0,0 +1,7 @@
+// PR c++/99232
+// { dg-additional-options "-fmodules-ts" }
+
+import pr99232;
+
+double foo() { return lambda * 2.0; }
+static_assert(a == 42);
-- 
2.42.0