static cxx_binding *cxx_binding_make (tree value, tree type);
static cp_binding_level *innermost_nonclass_level (void);
+static tree do_pushdecl_with_scope (tree x, cp_binding_level *, bool hiding);
static void set_identifier_type_value_with_scope (tree id, tree decl,
cp_binding_level *b);
static name_hint maybe_suggest_missing_std_header (location_t location,
DECL_CONTEXT (decl) = ctx;
}
-/* DECL is a local-scope decl with linkage. SHADOWED is true if the
- name is already bound at the current level.
-
- [basic.link] If there is a visible declaration of an entity with
- linkage having the same name and type, ignoring entities declared
- outside the innermost enclosing namespace scope, the block scope
- declaration declares that same entity and receives the linkage of
- the previous declaration.
-
- Also, make sure that this decl matches any existing external decl
- in the enclosing namespace. */
+/* DECL is a local extern decl. Find or create the namespace-scope
+ decl that it aliases. Also, determines the linkage of DECL. */
static void
-set_local_extern_decl_linkage (tree decl, bool shadowed)
+push_local_extern_decl_alias (tree decl)
{
- tree ns_value = decl; /* Unique marker. */
-
- if (!shadowed)
- {
- tree loc_value = innermost_non_namespace_value (DECL_NAME (decl));
- if (!loc_value)
- {
- ns_value
- = find_namespace_value (current_namespace, DECL_NAME (decl));
- loc_value = ns_value;
- }
- if (loc_value == error_mark_node
- /* An ambiguous lookup. */
- || (loc_value && TREE_CODE (loc_value) == TREE_LIST))
- loc_value = NULL_TREE;
-
- for (ovl_iterator iter (loc_value); iter; ++iter)
- if (!iter.hidden_p ()
- && (TREE_STATIC (*iter) || DECL_EXTERNAL (*iter))
- && decls_match (*iter, decl))
- {
- /* The standard only says that the local extern inherits
- linkage from the previous decl; in particular, default
- args are not shared. Add the decl into a hash table to
- make sure only the previous decl in this case is seen
- by the middle end. */
- struct cxx_int_tree_map *h;
-
- /* We inherit the outer decl's linkage. But we're a
- different decl. */
- TREE_PUBLIC (decl) = TREE_PUBLIC (*iter);
-
- if (cp_function_chain->extern_decl_map == NULL)
- cp_function_chain->extern_decl_map
- = hash_table<cxx_int_tree_map_hasher>::create_ggc (20);
-
- h = ggc_alloc<cxx_int_tree_map> ();
- h->uid = DECL_UID (decl);
- h->to = *iter;
- cxx_int_tree_map **loc = cp_function_chain->extern_decl_map
- ->find_slot (h, INSERT);
- *loc = h;
- break;
- }
- }
+ if (dependent_type_p (TREE_TYPE (decl)))
+ return;
+ /* EH specs were not part of the function type prior to c++17, but
+ we still can't go pushing dependent eh specs into the namespace. */
+ if (cxx_dialect < cxx17
+ && TREE_CODE (decl) == FUNCTION_DECL
+ && (value_dependent_expression_p
+ (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (decl)))))
+ return;
- if (TREE_PUBLIC (decl))
- {
- /* DECL is externally visible. Make sure it matches a matching
- decl in the namespace scope. We only really need to check
- this when inserting the decl, not when we find an existing
- match in the current scope. However, in practice we're
- going to be inserting a new decl in the majority of cases --
- who writes multiple extern decls for the same thing in the
- same local scope? Doing it here often avoids a duplicate
- namespace lookup. */
+ gcc_checking_assert (!DECL_LANG_SPECIFIC (decl)
+ || !DECL_TEMPLATE_INFO (decl));
+ if (DECL_LANG_SPECIFIC (decl) && DECL_LOCAL_DECL_ALIAS (decl))
+ /* We're instantiating a non-dependent local decl, it already
+ knows the alias. */
+ return;
- /* Avoid repeating a lookup. */
- if (ns_value == decl)
- ns_value = find_namespace_value (current_namespace, DECL_NAME (decl));
+ tree alias = NULL_TREE;
- if (ns_value == error_mark_node
- || (ns_value && TREE_CODE (ns_value) == TREE_LIST))
- ns_value = NULL_TREE;
+ if (DECL_SIZE (decl) && !TREE_CONSTANT (DECL_SIZE (decl)))
+ /* Do not let a VLA creep into a namespace. Diagnostic will be
+ emitted in layout_var_decl later. */
+ alias = error_mark_node;
+ else
+ {
+ /* First look for a decl that matches. */
+ tree ns = CP_DECL_CONTEXT (decl);
+ tree binding = find_namespace_value (ns, DECL_NAME (decl));
- for (ovl_iterator iter (ns_value); iter; ++iter)
- {
- tree other = *iter;
-
- if (!(TREE_PUBLIC (other) || DECL_EXTERNAL (other)))
- ; /* Not externally visible. */
- else if (DECL_EXTERN_C_P (decl) && DECL_EXTERN_C_P (other))
- ; /* Both are extern "C", we'll check via that mechanism. */
- else if (TREE_CODE (other) != TREE_CODE (decl)
- || ((VAR_P (decl) || matching_fn_p (other, decl))
- && !comptypes (TREE_TYPE (decl), TREE_TYPE (other),
- COMPARE_REDECLARATION)))
+ if (binding && TREE_CODE (binding) != TREE_LIST)
+ for (ovl_iterator iter (binding); iter; ++iter)
+ if (decls_match (*iter, decl))
{
- auto_diagnostic_group d;
- if (permerror (DECL_SOURCE_LOCATION (decl),
- "local external declaration %q#D", decl))
- inform (DECL_SOURCE_LOCATION (other),
- "does not match previous declaration %q#D", other);
+ alias = *iter;
break;
}
+
+ if (!alias)
+ {
+ /* No existing namespace-scope decl. Make one. */
+ alias = copy_decl (decl);
+
+ /* This is the real thing. */
+ DECL_LOCAL_DECL_P (alias) = false;
+
+ /* Expected default linkage is from the namespace. */
+ TREE_PUBLIC (alias) = TREE_PUBLIC (ns);
+ alias = do_pushdecl_with_scope (alias, NAMESPACE_LEVEL (ns),
+ /* hiding= */true);
}
}
+
+ retrofit_lang_decl (decl);
+ DECL_LOCAL_DECL_ALIAS (decl) = alias;
}
/* Record DECL as belonging to the current lexical scope. Check for
old = binding->value;
}
- if (current_function_decl && VAR_OR_FUNCTION_DECL_P (decl)
- && DECL_EXTERNAL (decl))
- set_local_extern_decl_linkage (decl, old != NULL_TREE);
-
if (old == error_mark_node)
old = NULL_TREE;
/* We need to check and register the decl now. */
check_extern_c_conflict (match);
}
+ else if (slot && !hiding
+ && STAT_HACK_P (*slot) && STAT_DECL_HIDDEN_P (*slot))
+ {
+ /* Unhide the non-function. */
+ gcc_checking_assert (old == match);
+ if (!STAT_TYPE (*slot))
+ *slot = match;
+ else
+ STAT_DECL (*slot) = match;
+ }
return match;
}
if (!instantiating_current_function_p ())
record_locally_defined_typedef (decl);
}
- else if (VAR_P (decl))
- maybe_register_incomplete_var (decl);
+ else
+ {
+ if (VAR_P (decl) && !DECL_LOCAL_DECL_P (decl))
+ maybe_register_incomplete_var (decl);
+
+ if (VAR_OR_FUNCTION_DECL_P (decl))
+ {
+ if (DECL_LOCAL_DECL_P (decl)
+ && TREE_CODE (CP_DECL_CONTEXT (decl)) == NAMESPACE_DECL)
+ push_local_extern_decl_alias (decl);
- if ((VAR_P (decl) || TREE_CODE (decl) == FUNCTION_DECL)
- && DECL_EXTERN_C_P (decl))
- check_extern_c_conflict (decl);
+ if (DECL_EXTERN_C_P (decl))
+ check_extern_c_conflict (decl);
+ }
+ }
}
else
add_decl_to_level (level, decl);
return ret;
}
-/* Returns true iff DECL is a block-scope extern declaration of a function
- or variable. We will already have determined validity of the decl
- when pushing it. So we do not have to redo that lookup. */
-
-bool
-is_local_extern (tree decl)
-{
- if ((TREE_CODE (decl) == FUNCTION_DECL
- || TREE_CODE (decl) == VAR_DECL))
- return DECL_LOCAL_DECL_P (decl);
-
- return false;
-}
-
/* The type TYPE is being declared. If it is a class template, or a
specialization of a class template, do any processing required and
perform error-checking. If IS_FRIEND is nonzero, this TYPE is
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