Re: [PATCH] PR c++/52343 - error with alias template as template template argument
OK. Jason
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
Jason Merrill ja...@redhat.com writes:
On 12/21/2012 07:35 AM, Dodji Seketeli wrote:
else if (TREE_TYPE (t)
INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
-!TREE_CONSTANT (t))
+!TREE_CONSTANT (t)
+ /* Class template and alias template arguments should be OK. */
+!DECL_TYPE_TEMPLATE_P (t))
Instead, let's add a previous else if to catch template template
arguments (and do nothing) so that when we hit this else if, we know
we're dealing with a non-type argument.
Right. Here you go.
Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.
gcc/cp/
PR c++/52343
* pt.c (check_instantiated_arg): Allow type template arguments.
gcc/testsuite/
PR c++/52343
* g++.dg/cpp0x/alias-decl-29.C: New test.
---
gcc/cp/pt.c| 3 +++
gcc/testsuite/g++.dg/cpp0x/alias-decl-29.C | 10 ++
2 files changed, 13 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/alias-decl-29.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 1b3f039..9e99c09 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -14421,6 +14421,9 @@ check_instantiated_arg (tree tmpl, tree t,
tsubst_flags_t complain)
return true;
}
}
+ /* Class template and alias template arguments should be OK. */
+ else if (DECL_TYPE_TEMPLATE_P (t))
+;
/* A non-type argument of integral or enumerated type must be a
constant. */
else if (TREE_TYPE (t)
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-29.C
b/gcc/testsuite/g++.dg/cpp0x/alias-decl-29.C
new file mode 100644
index 000..f6cc695
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-29.C
@@ -0,0 +1,10 @@
+// Origin: PR c++/52343
+// { dg-do compile { target c++11 } }
+
+templatetypename
+using A = int;
+
+templatetemplateclass class
+struct B {};
+
+BA b;
--
Dodji
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
Gabriel Dos Reis g...@integrable-solutions.net writes: G On Sun, Dec 23, 2012 at 11:04 PM, Jason Merrill ja...@redhat.com wrote: On 12/21/2012 07:35 AM, Dodji Seketeli wrote: else if (TREE_TYPE (t) INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t)) - !TREE_CONSTANT (t)) + !TREE_CONSTANT (t) + /* Class template and alias template arguments should be OK. */ + !DECL_TYPE_TEMPLATE_P (t)) Instead, let's add a previous else if to catch template template arguments (and do nothing) so that when we hit this else if, we know we're dealing with a non-type argument. Thanks; that would make the logic clearer. I would suggest that we abstract this series of conjunction into a separate (static inline) function, e.g. nontype_argument_p. These conjunctions represents a non-type argument only if they are satisfied /and/ the previous 'if' branches are not taken. So just putting the conjunctions in e.g, nontype_argument_p could be seen as confusion too, IMHO. Could we just consider that the patch + comment of my earlier message and the comment of these conjunctions /* A non-type argument of integral or enumerated type must be a constant. */ should make this less confusing? -- Dodji
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
On 12/21/2012 07:35 AM, Dodji Seketeli wrote: else if (TREE_TYPE (t) INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t)) - !TREE_CONSTANT (t)) + !TREE_CONSTANT (t) + /* Class template and alias template arguments should be OK. */ + !DECL_TYPE_TEMPLATE_P (t)) Instead, let's add a previous else if to catch template template arguments (and do nothing) so that when we hit this else if, we know we're dealing with a non-type argument. Jason
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
On Sun, Dec 23, 2012 at 11:04 PM, Jason Merrill ja...@redhat.com wrote: On 12/21/2012 07:35 AM, Dodji Seketeli wrote: else if (TREE_TYPE (t) INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t)) - !TREE_CONSTANT (t)) + !TREE_CONSTANT (t) + /* Class template and alias template arguments should be OK. */ + !DECL_TYPE_TEMPLATE_P (t)) Instead, let's add a previous else if to catch template template arguments (and do nothing) so that when we hit this else if, we know we're dealing with a non-type argument. Thanks; that would make the logic clearer. I would suggest that we abstract this series of conjunction into a separate (static inline) function, e.g. nontype_argument_p. -- Gaby
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
Gabriel Dos Reis g...@integrable-solutions.net writes:
Thank you very much for the explanation; your previous message
makes sense to me now.
You are welcome.
The question I have is why are we using TREE_TYPE of a TEMPLATE_DECL
to represent the current instantiation of a template alias?
My understanding is that in the instantiation at line 7 below
1 templatetypename
2 using A = int;
3
4 templatetemplateclass class
5 struct B {};
6
7 BA b;
check_instantiated_arg is not looking at the current instantiation of
the template alias A. Rather, it is looking at the template-name A
(which resolved, IMHO rightfully, to the decl for A which happens to be
a TEMPLATE_DECL). This seems consistent with the fact that the
parameter of B is a template itself so its argument ought to be
template-name, rather than a template instantiation.
--
Dodji
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
On Sat, Dec 22, 2012 at 9:53 AM, Dodji Seketeli do...@redhat.com wrote:
Gabriel Dos Reis g...@integrable-solutions.net writes:
Thank you very much for the explanation; your previous message
makes sense to me now.
You are welcome.
The question I have is why are we using TREE_TYPE of a TEMPLATE_DECL
to represent the current instantiation of a template alias?
My understanding is that in the instantiation at line 7 below
1 templatetypename
2 using A = int;
3
4 templatetemplateclass class
5 struct B {};
6
7 BA b;
check_instantiated_arg is not looking at the current instantiation of
the template alias A. Rather, it is looking at the template-name A
(which resolved, IMHO rightfully, to the decl for A which happens to be
a TEMPLATE_DECL). This seems consistent with the fact that the
parameter of B is a template itself so its argument ought to be
template-name, rather than a template instantiation.
Sorry for the confusion, current instantiation was the wrong word.
What I meant to say was that the use and interpretation of TREE_TYPE
is very confusing in this context.
-- Gaby
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
The example is valid, but I am not sure I understand your explanation... -- Gaby
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
Gabriel Dos Reis g...@integrable-solutions.net writes:
The example is valid, but I am not sure I understand your
explanation...
Ah, sorry. I realize just now that I haven't mentioned the initial
erratic behaviour. Maybe that could have made my message easier to
understand.
So consider the test case of the message:
1 templatetypename
2 using A = int;
3
4 templatetemplateclass class
5 struct B {};
6
7 BA b;
test.cc:7:4: error: integral expression ‘A’ is not constant
BA b;
^
Followed by some irrelevant other error messages.
As I was saying my earlier message, here, the TREE_TYPE of the
template_decl A is an integer; so check_instantiated_arg takes it as
if A is an integer value (a decl with integer type), and thus, should
be a constant.
The fix I am proposing is just to allow check_instantiated_arg to make
the difference between a classical integer decl, and an alias template
which type-id is an integer.
--
Dodji
Re: [PATCH] PR c++/52343 - error with alias template as template template argument
On Fri, Dec 21, 2012 at 10:25 AM, Dodji Seketeli do...@redhat.com wrote:
Gabriel Dos Reis g...@integrable-solutions.net writes:
The example is valid, but I am not sure I understand your
explanation...
Ah, sorry. I realize just now that I haven't mentioned the initial
erratic behaviour. Maybe that could have made my message easier to
understand.
So consider the test case of the message:
1 templatetypename
2 using A = int;
3
4 templatetemplateclass class
5 struct B {};
6
7 BA b;
test.cc:7:4: error: integral expression ‘A’ is not constant
BA b;
^
Followed by some irrelevant other error messages.
As I was saying my earlier message, here, the TREE_TYPE of the
template_decl A is an integer; so check_instantiated_arg takes it as
if A is an integer value (a decl with integer type), and thus, should
be a constant.
The fix I am proposing is just to allow check_instantiated_arg to make
the difference between a classical integer decl, and an alias template
which type-id is an integer.
--
Dodji
Hi Dodji,
Thank you very much for the explanation; your previous message
makes sense to me now. The question I have is why are we
using TREE_TYPE of a TEMPLATE_DECL to represent the
current instantiation of a template alias? Should not we use
TEMPLATE_RESULT instead?
-- Gaby
