This is an ICE-on-invalid, but I keep seeing it when reducing code so
I'd like to fix it. We crash on
template <typename> void forward() {
concept C = true;
}
which breaks two requirements:
[temp.concept]/1: A concept is a template ...
[temp.concept]/3: A concept-definition shall inhabit a namespace scope.
This patch adds a test that exercises broken code and fixes the ICE
by checking that a concept-definition is defined at namespace scope.
gcc/cp/ChangeLog:
PR c++/97536
* decl.c (grokvardecl): Given an error when a concept is not defined
at namespace scope.
gcc/testsuite/ChangeLog:
PR c++/97536
* g++.dg/concepts/diagnostic16.C: New test.
"a non-template variable cannot be %<concept%>");
return NULL_TREE;
}
+ else if (!at_namespace_scope_p ())
+ {
+ error_at (declspecs->locations[ds_concept],
+ "concept must be defined at namespace scope");
+ return NULL_TREE;
+ }
else
DECL_DECLARED_CONCEPT_P (decl) = true;
if (!same_type_ignoring_top_level_qualifiers_p (type, boolean_type_node))
--- /dev/null
+// PR c++/97536
+// { dg-do compile { target concepts } }
+
+template<typename>
+concept C1 = true;
+
+concept C2 = true; // { dg-error "non-template variable cannot be .concept." }
+// { dg-error "concept definition syntax is" "" { target *-*-* } .-1 }
+
+template<typename>
+void fn1 ()
+{
+ concept bar = true; // { dg-error "concept must be defined at namespace scope" }
+// { dg-error "concept definition syntax is" "" { target *-*-* } .-1 }
+}
+
+void fn2 ()
+{
+ concept bar = true; // { dg-error "non-template variable cannot be .concept." }
+// { dg-error "concept definition syntax is" "" { target *-*-* } .-1 }
+}
+
+template<typename>
+void fn3 ()
+{
+ template<typename> // { dg-error "template declaration cannot appear at block scope" }
+ concept bar = true;
+}
+
+void fn4 ()
+{
+ template<typename> // { dg-error "template declaration cannot appear at block scope" }
+ concept bar = true;
+}
+
+void fn5 ()
+{
+ C1 auto x = 42;
+}
+
+template<typename>
+void fn6 ()
+{
+ C1 auto x = 42;
+}