On Thu, Nov 23, 2023 at 11:45:31AM -0500, Nathan Sidwell wrote:
> On 11/13/23 01:09, Nathaniel Shead wrote:
> > I happened to be browsing the standard a bit later and noticed that we
> > incorrectly reject the example given below.
> >
> > Bootstrapped on x86_64-pc-linux-gnu; regtesting ongoing but modules.exp
> > completed with no errors.
> >
> > -- >8 --
> >
> > A typedef doesn't create a new entity, and thus should be allowed to be
> > exported even if it has been previously declared un-exported. See the
> > example in [module.interface] p6:
>
> ok. Could you put a reference to [module.interface]/p6 in the comment though?
>
> nathan
>
Thanks. I've also added a new test to ensure that the redeclarations are
actually exported. Ok for trunk?
-- >8 --
A typedef doesn't create a new entity, and thus should be allowed to be
exported even if it has been previously declared un-exported. See the
example in [module.interface] p6:
export module M;
struct S { int n; };
typedef S S;
export typedef S S; // OK, does not redeclare an entity
PR c++/102341
gcc/cp/ChangeLog:
* decl.cc (duplicate_decls): Allow exporting a redeclaration of
a typedef.
gcc/testsuite/ChangeLog:
* g++.dg/modules/export-1.C: Adjust test.
* g++.dg/modules/export-2_a.C: New test.
* g++.dg/modules/export-2_b.C: New test.
Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
---
gcc/cp/decl.cc | 6 +++++-
gcc/testsuite/g++.dg/modules/export-1.C | 6 +++++-
gcc/testsuite/g++.dg/modules/export-2_a.C | 14 ++++++++++++++
gcc/testsuite/g++.dg/modules/export-2_b.C | 7 +++++++
4 files changed, 31 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/modules/export-2_a.C
create mode 100644 gcc/testsuite/g++.dg/modules/export-2_b.C
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 16b04ebe0f8..f8324f92ca7 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -2231,7 +2231,11 @@ duplicate_decls (tree newdecl, tree olddecl, bool
hiding, bool was_hidden)
}
tree not_tmpl = STRIP_TEMPLATE (olddecl);
- if (DECL_LANG_SPECIFIC (not_tmpl) && DECL_MODULE_ATTACH_P (not_tmpl))
+ if (DECL_LANG_SPECIFIC (not_tmpl)
+ && DECL_MODULE_ATTACH_P (not_tmpl)
+ /* Typedefs are not entities and so are OK to be redeclared
+ as exported: see [module.interface] p6. */
+ && TREE_CODE (olddecl) != TYPE_DECL)
{
if (DECL_MODULE_EXPORT_P (STRIP_TEMPLATE (newdecl))
&& !DECL_MODULE_EXPORT_P (not_tmpl))
diff --git a/gcc/testsuite/g++.dg/modules/export-1.C
b/gcc/testsuite/g++.dg/modules/export-1.C
index 3f93814d270..598814370ec 100644
--- a/gcc/testsuite/g++.dg/modules/export-1.C
+++ b/gcc/testsuite/g++.dg/modules/export-1.C
@@ -9,8 +9,12 @@ export int x (); // { dg-error "conflicting exporting for
declaration" }
int y;
export extern int y; // { dg-error "conflicting exporting for declaration" }
+// A typedef is not an entity so the following is OK; see [module.interface]
example 4
typedef int z;
-export typedef int z; // { dg-error "conflicting exporting for declaration" }
+export typedef int z; // { dg-bogus "conflicting exporting for declaration" }
+
+template <typename T> using w = T;
+export template <typename T> using w = T; // { dg-error "conflicting
exporting for declaration" }
template <typename T> int f (T);
export template <typename T> int f (T); // { dg-error "conflicting exporting
for declaration" }
diff --git a/gcc/testsuite/g++.dg/modules/export-2_a.C
b/gcc/testsuite/g++.dg/modules/export-2_a.C
new file mode 100644
index 00000000000..9a201bf37c0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/export-2_a.C
@@ -0,0 +1,14 @@
+// { dg-additional-options "-fmodules-ts" }
+// { dg-module-cmi aliases }
+
+export module aliases;
+
+typedef int x;
+export typedef int x;
+
+using y = double;
+export using y = double;
+
+struct S {};
+using T = S;
+export using T = S;
diff --git a/gcc/testsuite/g++.dg/modules/export-2_b.C
b/gcc/testsuite/g++.dg/modules/export-2_b.C
new file mode 100644
index 00000000000..456aa8d9ec8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/export-2_b.C
@@ -0,0 +1,7 @@
+// { dg-additional-options "-fmodules-ts" }
+
+import aliases;
+
+x a = 123;
+y b = 12.45;
+T c = T{};
--
2.42.0
