Add more diagnostics for variable concepts. Also fix a regression
where non-template concepts variables were causing ICEs because they
aren't being allocated via build_lang_decl.
2014-08-15 Andrew Sutton <andrew.n.sut...@gmail.com>
Additional declaration restrictions on variable concepts.
* gcc/cp/decl.c (is_concept_var): New.
(cp_finish_decl): Check for uninitialized variable
concepts.
(grokvardecl): Don't set the concept flag for non-template variables.
* g++.dg/concepts/decl-diagnose.C: Add tests.
Andrew Sutton
Index: gcc/cp/decl.c
===================================================================
--- gcc/cp/decl.c (revision 214239)
+++ gcc/cp/decl.c (working copy)
@@ -6259,6 +6259,16 @@ value_dependent_init_p (tree init)
return false;
}
+// Returns true if a DECL is VAR_DECL with the concept specifier. Note
+// that not all variables are decl-lang-specific.
+static inline bool
+is_concept_var (tree decl)
+{
+ return VAR_P (decl)
+ && DECL_LANG_SPECIFIC (decl)
+ && DECL_DECLARED_CONCEPT_P (decl);
+}
+
/* Finish processing of a declaration;
install its line number and initial value.
If the length of an array type is not known before,
@@ -6435,6 +6445,8 @@ cp_finish_decl (tree decl, tree init, bo
init = NULL_TREE;
release_tree_vector (cleanups);
}
+ else if (!init && is_concept_var (decl))
+ error ("variable concept has no initializer");
else if (!DECL_PRETTY_FUNCTION_P (decl))
{
/* Deduce array size even if the initializer is dependent. */
@@ -8264,9 +8276,17 @@ grokvardecl (tree type,
else
DECL_INTERFACE_KNOWN (decl) = 1;
- // Mark the variable as a concept.
+ // Check that the variable can be safely declared as a concept.
if (conceptp)
- DECL_DECLARED_CONCEPT_P (decl) = true;
+ {
+ if (!processing_template_decl)
+ {
+ error ("a non-template variable cannot be %<concept%>");
+ return NULL_TREE;
+ }
+ else
+ DECL_DECLARED_CONCEPT_P (decl) = true;
+ }
// Handle explicit specializations and instantiations of variable templates.
if (orig_declarator)
