Re: [C++ Patch] PR 52487
On 03/22/2012 07:28 PM, Jason Merrill wrote:
On 03/22/2012 12:58 PM, Paolo Carlini wrote:
Anyway, I also think not calling literal_type_p from check_field_decls
if the type is incomplete is pretty ugly, but I'm not sure which is the
best way to make progress
I guess that's OK. Just add a comment explaining that we'll get an
error later.
Done: I applied the below to mainline and 4_7-branch.
Thanks!
Paolo.
///
/cp
2012-03-22 Paolo Carlini
PR c++/52487
* class.c (check_field_decls): Call literal_type_p only
on complete types.
/testsuite
2012-03-22 Paolo Carlini
PR c++/52487
* g++.dg/cpp0x/lambda/lambda-ice7.C: New.
Index: testsuite/g++.dg/cpp0x/lambda/lambda-ice7.C
===
--- testsuite/g++.dg/cpp0x/lambda/lambda-ice7.C (revision 0)
+++ testsuite/g++.dg/cpp0x/lambda/lambda-ice7.C (revision 0)
@@ -0,0 +1,9 @@
+// PR c++/52487
+// { dg-options "-std=c++0x" }
+
+struct A; // { dg-error "forward declaration" }
+
+void foo(A& a)
+{
+ [=](){a;}; // { dg-error "invalid use of incomplete type" }
+}
Index: cp/class.c
===
--- cp/class.c (revision 185715)
+++ cp/class.c (working copy)
@@ -3149,8 +3149,9 @@ check_field_decls (tree t, tree *access_decls,
CLASSTYPE_NON_AGGREGATE (t) = 1;
/* If at least one non-static data member is non-literal, the whole
- class becomes non-literal. */
- if (!literal_type_p (type))
+ class becomes non-literal. Note: if the type is incomplete we
+will complain later on. */
+ if (COMPLETE_TYPE_P (type) && !literal_type_p (type))
CLASSTYPE_LITERAL_P (t) = false;
/* A standard-layout class is a class that:
Re: [C++ Patch] PR 52487
On 03/22/2012 12:58 PM, Paolo Carlini wrote: Anyway, I also think not calling literal_type_p from check_field_decls if the type is incomplete is pretty ugly, but I'm not sure which is the best way to make progress I guess that's OK. Just add a comment explaining that we'll get an error later. Jason
Re: [C++ Patch] PR 52487
On Thu, Mar 22, 2012 at 11:58 AM, Paolo Carlini wrote: > On 03/22/2012 03:49 PM, Jason Merrill wrote: >> >> It's ill-formed to have a field with incomplete type. The best thing >> would be to complain about that before we get to literal_type_p so that >> errorcount is set, if that's not too complicated. > > Agreed. The problem is that if we just change check_field_decls to produce > an error about the incomplete field, we produce also another later: that is, Can't we set a bit saying that the field has already gone through diagnostics, just like we do when trying to avoid duplicate warnings? > considering cp_parser_lambda_expression, we get to check_field_decls from > finish_struct, but we eventually also produce an error with > cxx_incomplete_type_diagnostic from build_lambda_object (-> force_rvalue -> > build_special_member_call -> complete_type_or_maybe_complain) > > Anyway, I also think not calling literal_type_p from check_field_decls if > the type is incomplete is pretty ugly, but I'm not sure which is the best > way to make progress: I could try returning a boolean from check_field_decls > if something goes wrong in order to bail out early from > cp_parser_lambda_expression (at the moment, finish_struct_1, > check_bases_and_members, all return void). Or I could try to catch the > incomplete field even *before* check_field_decls. > > What do you suggest? > > Thanks, > Paolo. >
Re: [C++ Patch] PR 52487
On 03/22/2012 03:49 PM, Jason Merrill wrote: It's ill-formed to have a field with incomplete type. The best thing would be to complain about that before we get to literal_type_p so that errorcount is set, if that's not too complicated. Agreed. The problem is that if we just change check_field_decls to produce an error about the incomplete field, we produce also another later: that is, considering cp_parser_lambda_expression, we get to check_field_decls from finish_struct, but we eventually also produce an error with cxx_incomplete_type_diagnostic from build_lambda_object (-> force_rvalue -> build_special_member_call -> complete_type_or_maybe_complain) Anyway, I also think not calling literal_type_p from check_field_decls if the type is incomplete is pretty ugly, but I'm not sure which is the best way to make progress: I could try returning a boolean from check_field_decls if something goes wrong in order to bail out early from cp_parser_lambda_expression (at the moment, finish_struct_1, check_bases_and_members, all return void). Or I could try to catch the incomplete field even *before* check_field_decls. What do you suggest? Thanks, Paolo.
Re: [C++ Patch] PR 52487
It's ill-formed to have a field with incomplete type. The best thing would be to complain about that before we get to literal_type_p so that errorcount is set, if that's not too complicated. Jason
Re: [C++ Patch] PR 52487
... this simple also passes testing.
Paolo.
/cp
2012-03-20 Paolo Carlini
PR c++/52487
* class.c (check_field_decls): Call literal_type_p only
on complete types.
/testsuite
2012-03-20 Paolo Carlini
PR c++/52487
* g++.dg/cpp0x/lambda/lambda-ice7.C: New.
Index: testsuite/g++.dg/cpp0x/lambda/lambda-ice7.C
===
--- testsuite/g++.dg/cpp0x/lambda/lambda-ice7.C (revision 0)
+++ testsuite/g++.dg/cpp0x/lambda/lambda-ice7.C (revision 0)
@@ -0,0 +1,9 @@
+// PR c++/52487
+// { dg-options "-std=c++0x" }
+
+struct A; // { dg-error "forward declaration" }
+
+void foo(A& a)
+{
+ [=](){a;}; // { dg-error "invalid use of incomplete type" }
+}
Index: cp/class.c
===
--- cp/class.c (revision 185588)
+++ cp/class.c (working copy)
@@ -3150,7 +3150,7 @@ check_field_decls (tree t, tree *access_decls,
/* If at least one non-static data member is non-literal, the whole
class becomes non-literal. */
- if (!literal_type_p (type))
+ if (COMPLETE_TYPE_P (type) && !literal_type_p (type))
CLASSTYPE_LITERAL_P (t) = false;
/* A standard-layout class is a class that:
Re: [C++ Patch] PR 52487
On 03/20/2012 08:22 PM, Jason Merrill wrote: That assert is there to make sure that we don't try to test for literality of an incomplete type. We should check for completeness before trying to check for literality. You mean, in the relevant caller, here in check_field_decls: /* If at least one non-static data member is non-literal, the whole class becomes non-literal. */ if (!literal_type_p (type)) CLASSTYPE_LITERAL_P (t) = false; essentially setting CLASSTYPE_LITERAL_P (t) = false; also when CLASS_TYPE_P (type) && !COMPLETE_TYPE_P (complete_type (type) or maybe just CLASS_TYPE_P (type) && !COMPLETE_TYPE_P (type) ? Thanks, Paolo.
Re: [C++ Patch] PR 52487
That assert is there to make sure that we don't try to test for literality of an incomplete type. We should check for completeness before trying to check for literality. Jason
