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

[Nathan Sidwell]

On 11/15/23 07:24, Nathaniel Shead wrote:
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).

ok, but can you augment the testcase to check the address is the same in both 
TUs?  (something like an accessor in the module and a runtime-check in the 
importer?)

nathan


        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);

--
Nathan Sidwell