The problem in the PR was that make_temporary_var_for_ref_to_temp ran before
determine_visibility, so when we copied the linkage of the reference
variable it had not yet been restricted by its anonymous namespace context,
so the temporary wrongly ended up with TREE_PUBLIC set. The natural
solution is to run determine_visibility earlier. But that needs to happen
after maybe_commonize_var increases the linkage of some local variables, and
on targets without weak symbol support, that function does different things
based on the results of check_initializer, which is what calls
make_temporary_var_for_ref_to_temp. To break this circular dependency I'm
calling maybe_commonize_var early, and then again later if the target
doesn't support weak symbols.
It also occurred to me that make_temporary_var_for_ref_to_temp wasn't
handling DECL_VISIBILITY at all, and verified that we were doing the wrong
thing. So I've combined the linkage-copying code from there and two other
places.
Tested x86_64-pc-linux-gnu, applying to trunk.
* decl2.c (copy_linkage): Factor out of get_guard.
* call.c (make_temporary_var_for_ref_to_temp): Use it.
* decl.c (cp_finish_decomp): Use it.
(cp_finish_decl): determine_visibility sooner.
---
gcc/cp/cp-tree.h | 1 +
gcc/cp/call.c | 9 +----
gcc/cp/decl.c | 33 +++++++----------
gcc/cp/decl2.c | 36 ++++++++++++-------
.../g++.dg/ext/visibility/ref-temp1.C | 17 +++++++++
5 files changed, 55 insertions(+), 41 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/ext/visibility/ref-temp1.C
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 890d5a27350..77bcf046608 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -6636,6 +6636,7 @@ extern bool mark_used (tree);
extern bool mark_used (tree, tsubst_flags_t);
extern void finish_static_data_member_decl (tree, tree, bool, tree, int);
extern tree cp_build_parm_decl (tree, tree, tree);
+extern void copy_linkage (tree, tree);
extern tree get_guard (tree);
extern tree get_guard_cond (tree, bool);
extern tree set_guard (tree);
diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index d47747117b9..aacd961faa1 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -11973,14 +11973,7 @@ make_temporary_var_for_ref_to_temp (tree decl, tree
type)
GR and suffixed with a sequence number mangled using the usual rules
for a seq-id. Temporaries are numbered with a pre-order, depth-first,
left-to-right walk of the complete initializer. */
-
- TREE_STATIC (var) = TREE_STATIC (decl);
- TREE_PUBLIC (var) = TREE_PUBLIC (decl);
- if (vague_linkage_p (decl))
- comdat_linkage (var);
-
- CP_DECL_THREAD_LOCAL_P (var) = CP_DECL_THREAD_LOCAL_P (decl);
- set_decl_tls_model (var, DECL_TLS_MODEL (decl));
+ copy_linkage (var, decl);
tree name = mangle_ref_init_variable (decl);
DECL_NAME (var) = name;
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 28a79029d92..47ff7eea88f 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7657,6 +7657,14 @@ cp_finish_decl (tree decl, tree init, bool
init_const_expr_p,
TREE_READONLY (decl) = 0;
}
+ /* This needs to happen before extend_ref_init_temps. */
+ if (VAR_OR_FUNCTION_DECL_P (decl))
+ {
+ if (VAR_P (decl))
+ maybe_commonize_var (decl);
+ determine_visibility (decl);
+ }
+
if (VAR_P (decl))
{
duration_kind dk = decl_storage_duration (decl);
@@ -7786,12 +7794,11 @@ cp_finish_decl (tree decl, tree init, bool
init_const_expr_p,
if (VAR_P (decl))
{
layout_var_decl (decl);
- maybe_commonize_var (decl);
+ if (!flag_weak)
+ /* Check again now that we have an initializer. */
+ maybe_commonize_var (decl);
}
- /* This needs to happen after the linkage is set. */
- determine_visibility (decl);
-
if (var_definition_p && TREE_STATIC (decl))
{
/* If a TREE_READONLY variable needs initialization
@@ -8328,23 +8335,7 @@ cp_finish_decomp (tree decl, tree first, unsigned int
count)
}
if (!processing_template_decl)
{
- TREE_PUBLIC (v[i]) = TREE_PUBLIC (decl);
- TREE_STATIC (v[i]) = TREE_STATIC (decl);
- DECL_COMMON (v[i]) = DECL_COMMON (decl);
- DECL_COMDAT (v[i]) = DECL_COMDAT (decl);
- if (TREE_STATIC (v[i]))
- {
- CP_DECL_THREAD_LOCAL_P (v[i])
- = CP_DECL_THREAD_LOCAL_P (decl);
- set_decl_tls_model (v[i], DECL_TLS_MODEL (decl));
- if (DECL_ONE_ONLY (decl))
- make_decl_one_only (v[i], cxx_comdat_group (v[i]));
- if (TREE_PUBLIC (decl))
- DECL_WEAK (v[i]) = DECL_WEAK (decl);
- DECL_VISIBILITY (v[i]) = DECL_VISIBILITY (decl);
- DECL_VISIBILITY_SPECIFIED (v[i])
- = DECL_VISIBILITY_SPECIFIED (decl);
- }
+ copy_linkage (v[i], decl);
cp_finish_decl (v[i], init, /*constexpr*/false,
/*asm*/NULL_TREE, LOOKUP_NORMAL);
}
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 042d6fa12df..1ecf0b937d5 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -3214,6 +3214,29 @@ build_cleanup (tree decl)
return clean;
}
+/* GUARD is a helper variable for DECL; make them have the same linkage and
+ visibility. */
+
+void
+copy_linkage (tree guard, tree decl)
+{
+ TREE_PUBLIC (guard) = TREE_PUBLIC (decl);
+ TREE_STATIC (guard) = TREE_STATIC (decl);
+ DECL_COMMON (guard) = DECL_COMMON (decl);
+ DECL_COMDAT (guard) = DECL_COMDAT (decl);
+ if (TREE_STATIC (guard))
+ {
+ CP_DECL_THREAD_LOCAL_P (guard) = CP_DECL_THREAD_LOCAL_P (decl);
+ set_decl_tls_model (guard, DECL_TLS_MODEL (decl));
+ /* We can't rely on DECL_WEAK (decl) or DECL_ONE_ONLY (decl) here, as
+ they may not be set until import_export_decl at EOF. */
+ if (vague_linkage_p (decl))
+ comdat_linkage (guard);
+ DECL_VISIBILITY (guard) = DECL_VISIBILITY (decl);
+ DECL_VISIBILITY_SPECIFIED (guard) = DECL_VISIBILITY_SPECIFIED (decl);
+ }
+}
+
/* Returns the initialization guard variable for the variable DECL,
which has static storage duration. */
@@ -3236,18 +3259,7 @@ get_guard (tree decl)
VAR_DECL, sname, guard_type);
/* The guard should have the same linkage as what it guards. */
- TREE_PUBLIC (guard) = TREE_PUBLIC (decl);
- TREE_STATIC (guard) = TREE_STATIC (decl);
- DECL_COMMON (guard) = DECL_COMMON (decl);
- DECL_COMDAT (guard) = DECL_COMDAT (decl);
- CP_DECL_THREAD_LOCAL_P (guard) = CP_DECL_THREAD_LOCAL_P (decl);
- set_decl_tls_model (guard, DECL_TLS_MODEL (decl));
- if (DECL_ONE_ONLY (decl))
- make_decl_one_only (guard, cxx_comdat_group (guard));
- if (TREE_PUBLIC (decl))
- DECL_WEAK (guard) = DECL_WEAK (decl);
- DECL_VISIBILITY (guard) = DECL_VISIBILITY (decl);
- DECL_VISIBILITY_SPECIFIED (guard) = DECL_VISIBILITY_SPECIFIED (decl);
+ copy_linkage (guard, decl);
DECL_ARTIFICIAL (guard) = 1;
DECL_IGNORED_P (guard) = 1;
diff --git a/gcc/testsuite/g++.dg/ext/visibility/ref-temp1.C
b/gcc/testsuite/g++.dg/ext/visibility/ref-temp1.C
new file mode 100644
index 00000000000..ecb62326e1b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/visibility/ref-temp1.C
@@ -0,0 +1,17 @@
+// PR c++/91476
+// Test that hidden and internal visibility propagates to reference temps.
+
+#define HIDDEN __attribute((visibility("hidden")))
+
+// { dg-final { scan-hidden "_ZGRZ1fvE3foo_" } }
+HIDDEN inline const int* f() { static const int &foo = 1; return &foo; }
+
+// { dg-final { scan-assembler-not
"(weak|globl)\[^\n\]*_ZGRN12_GLOBAL__N_13fooE_" } }
+namespace { const int &foo = 1; }
+
+const void *volatile p;
+int main()
+{
+ p = f();
+ p = &foo;
+}
base-commit: f0aec8643830a50812aeec0296086ed338aac678
--
2.18.1
