Tested on x86_64-pc-linux-gnu, OK for trunk if full bootstrap + regtest
passes?
-- >8 --
There are two issues with no-linkage decls (e.g. explicit type aliases)
in unnamed namespaces that this patch fixes.
Firstly, we don't currently handle exporting no-linkage decls in unnamed
namespaces. This should be ill-formed in [module.export], since having
an exported declaration within a namespace-definition makes the
namespace definition exported (p2), but an unnamed namespace has
internal linkage thus violating p3.
Secondly, by the standard it appears to be possible to emit unnamed
namespaces from named modules in certain scenarios. This patch makes
the adjustments needed to ensure we don't error in this case.
PR c++/118799
gcc/cp/ChangeLog:
* module.cc (depset::hash::is_tu_local_entity): Only types,
functions, variables, and template (specialisations) can be
TU-local.
(module_state::write_namespaces): Allow unnamed namespaces in
named modules.
(check_module_decl_linkage): Error for all exported declarations
in an unnamed namespace.
gcc/testsuite/ChangeLog:
* g++.dg/modules/export-6.C: Adjust error message, add check for
no-linkage decls in namespace.
* g++.dg/modules/internal-4_b.C: Allow exposing a namespace with
internal linkage.
* g++.dg/modules/using-30_a.C: New test.
* g++.dg/modules/using-30_b.C: New test.
* g++.dg/modules/using-30_c.C: New test.
Signed-off-by: Nathaniel Shead <nathanielosh...@gmail.com>
---
gcc/cp/module.cc | 35 ++++++++++++++++-----
gcc/testsuite/g++.dg/modules/export-6.C | 33 ++++++++++---------
gcc/testsuite/g++.dg/modules/internal-4_b.C | 4 +--
gcc/testsuite/g++.dg/modules/using-30_a.C | 9 ++++++
gcc/testsuite/g++.dg/modules/using-30_b.C | 6 ++++
gcc/testsuite/g++.dg/modules/using-30_c.C | 13 ++++++++
6 files changed, 77 insertions(+), 23 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/modules/using-30_a.C
create mode 100644 gcc/testsuite/g++.dg/modules/using-30_b.C
create mode 100644 gcc/testsuite/g++.dg/modules/using-30_c.C
diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 59716e1873e..21251f98a35 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -13332,6 +13332,14 @@ depset::hash::is_tu_local_entity (tree decl, bool
explain/*=false*/)
{
gcc_checking_assert (DECL_P (decl));
+ /* Only types, functions, variables, and template (specialisations)
+ can be TU-local. */
+ if (TREE_CODE (decl) != TYPE_DECL
+ && TREE_CODE (decl) != FUNCTION_DECL
+ && TREE_CODE (decl) != VAR_DECL
+ && TREE_CODE (decl) != TEMPLATE_DECL)
+ return false;
+
/* An explicit type alias is not an entity, and so is never TU-local.
Neither are the built-in declarations of 'int' and such. */
if (TREE_CODE (decl) == TYPE_DECL
@@ -16433,8 +16441,9 @@ module_state::write_namespaces (elf_out *to, vec<depset
*> spaces,
depset *b = spaces[ix];
tree ns = b->get_entity ();
+ /* This could be an anonymous namespace even for a named module,
+ since we can still emit no-linkage decls. */
gcc_checking_assert (TREE_CODE (ns) == NAMESPACE_DECL);
- gcc_checking_assert (TREE_PUBLIC (ns) || header_module_p ());
unsigned flags = 0;
if (TREE_PUBLIC (ns))
@@ -20394,13 +20403,25 @@ check_module_decl_linkage (tree decl)
/* An internal-linkage declaration cannot be generally be exported.
But it's OK to export any declaration from a header unit, including
internal linkage declarations. */
- if (!header_module_p ()
- && DECL_MODULE_EXPORT_P (decl)
- && decl_linkage (decl) == lk_internal)
+ if (!header_module_p () && DECL_MODULE_EXPORT_P (decl))
{
- error_at (DECL_SOURCE_LOCATION (decl),
- "exporting declaration %qD with internal linkage", decl);
- DECL_MODULE_EXPORT_P (decl) = false;
+ /* Let's additionally treat any exported declaration within an
+ internal namespace as exporting a declaration with internal
+ linkage, as this would implicitly also export the internal
+ linkage namespace. */
+ if (decl_internal_context_p (decl))
+ {
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "exporting declaration %qD declared in unnamed namespace",
+ decl);
+ DECL_MODULE_EXPORT_P (decl) = false;
+ }
+ else if (decl_linkage (decl) == lk_internal)
+ {
+ error_at (DECL_SOURCE_LOCATION (decl),
+ "exporting declaration %qD with internal linkage", decl);
+ DECL_MODULE_EXPORT_P (decl) = false;
+ }
}
}
diff --git a/gcc/testsuite/g++.dg/modules/export-6.C
b/gcc/testsuite/g++.dg/modules/export-6.C
index 460cdf08ea9..af54e5fbe87 100644
--- a/gcc/testsuite/g++.dg/modules/export-6.C
+++ b/gcc/testsuite/g++.dg/modules/export-6.C
@@ -16,27 +16,32 @@ export static auto [d] = S{}; // { dg-error "internal
linkage" "" { target c++2
#endif
namespace {
- export int y = 456; // { dg-error "internal linkage" }
- export void h(); // { dg-error "internal linkage" }
- export void i() {} // { dg-error "internal linkage" }
- export template <typename T> void v(); // { dg-error "internal linkage" }
- export template <typename T> void w() {} // { dg-error "internal linkage" }
- export auto [e] = S{}; // { dg-error "internal linkage" }
+ export int y = 456; // { dg-error "exporting" }
+ export void h(); // { dg-error "exporting" }
+ export void i() {} // { dg-error "exporting" }
+ export template <typename T> void v(); // { dg-error "exporting" }
+ export template <typename T> void w() {} // { dg-error "exporting" }
+ export auto [e] = S{}; // { dg-error "exporting" }
- export namespace ns {} // { dg-error "internal linkage" }
- export namespace alias = global; // { dg-error "internal linkage" }
+ export namespace ns {} // { dg-error "exporting" }
+ export namespace alias = global; // { dg-error "exporting" }
- export struct A {}; // { dg-error "internal linkage" }
- export template <typename T> struct B {}; // { dg-error "internal linkage" }
+ export struct A {}; // { dg-error "exporting" }
+ export template <typename T> struct B {}; // { dg-error "exporting" }
- export enum E {}; // { dg-error "internal linkage" }
- export enum class F {}; // { dg-error "internal linkage" }
+ export enum E {}; // { dg-error "exporting" }
+ export enum class F {}; // { dg-error "exporting" }
- export template <typename T> using U = int; // { dg-error "internal
linkage" }
+ export template <typename T> using U = int; // { dg-error "exporting" }
#if __cplusplus >= 202002L
- export template <typename T> concept C = true; // { dg-error "internal
linkage" "" { target c++20 } }
+ export template <typename T> concept C = true; // { dg-error "exporting" ""
{ target c++20 } }
#endif
+
+ // Also complain about exporting no-linkage decls in an unnamed namespace
+ export typedef int T; // { dg-error "exporting" }
+ export typedef struct {} *PC; // { dg-error "exporting" }
+ export using V = int; // { dg-error "exporting" }
}
export namespace {} // { dg-error "exporting unnamed namespace" }
diff --git a/gcc/testsuite/g++.dg/modules/internal-4_b.C
b/gcc/testsuite/g++.dg/modules/internal-4_b.C
index 81fc65a69bd..7e4fbfeb1fb 100644
--- a/gcc/testsuite/g++.dg/modules/internal-4_b.C
+++ b/gcc/testsuite/g++.dg/modules/internal-4_b.C
@@ -32,8 +32,8 @@ inline void expose_header_decl() { // { dg-error "exposes
TU-local entity" }
header_f();
}
-// We additionally consider a namespace with internal linkage as TU-local
-namespace expose_ns = internal_ns; // { dg-error "exposes TU-local entity" }
+// A namespace with internal linkage is not inherently an exposure.
+namespace expose_ns = internal_ns; // { dg-bogus "exposes TU-local entity" }
// But we don't consider a weakref as being TU-local, despite being
// marked static; this is to support uses of weakrefs in header files
diff --git a/gcc/testsuite/g++.dg/modules/using-30_a.C
b/gcc/testsuite/g++.dg/modules/using-30_a.C
new file mode 100644
index 00000000000..fc6a67f2bae
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/using-30_a.C
@@ -0,0 +1,9 @@
+// { dg-additional-options "-fmodules" }
+// { dg-module-cmi M }
+
+export module M;
+
+namespace {
+ using A = int;
+ typedef int B;
+}
diff --git a/gcc/testsuite/g++.dg/modules/using-30_b.C
b/gcc/testsuite/g++.dg/modules/using-30_b.C
new file mode 100644
index 00000000000..ba06c9de792
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/using-30_b.C
@@ -0,0 +1,6 @@
+// { dg-additional-options "-fmodules" }
+
+module M;
+
+A x;
+B y;
diff --git a/gcc/testsuite/g++.dg/modules/using-30_c.C
b/gcc/testsuite/g++.dg/modules/using-30_c.C
new file mode 100644
index 00000000000..34dc6f2c98d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/using-30_c.C
@@ -0,0 +1,13 @@
+// { dg-additional-options "-fmodules" }
+// The different declarations in the anonymous namespace shouldn't clash with
+// those in M.
+
+namespace {
+ using A = double;
+ typedef double B;
+}
+import M;
+int main() {
+ A a = 1.0;
+ B b = 2.0;
+}
--
2.47.0
