Re: [C++ Patch] PR 57543

[Paolo Carlini <paolo dot carlini at oracle dot com>]

Hi,

On 05/28/2014 05:14 PM, Jason Merrill wrote:
> On 05/28/2014 06:15 AM, Paolo Carlini wrote:
> > +  bool do_inject = (!current_class_ref
> > +            && TREE_CODE (t) == METHOD_TYPE
> > +            && TREE_CODE (TREE_TYPE (t)) == DECLTYPE_TYPE);
>
> Let's do this for any METHOD_TYPE; the decltype could be nested as a 
> template argument.  And current_class_ref might be for the wrong class.
Ok.
> > +      /* DR 1207: 'this' is in scope in the trailing return type.  */
> > +      tree this_type = (current_class_type
> > +            ? current_class_type
> > +            : TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t))));
>
> And here let's use class_of_this_parm unconditionally.
But unconditionally doesn't work, without doing something more. For 
example for the first test, as reported: when current_class_type is set 
and equal to "struct X<int>", class_of_this_parm is "struct X< 
<template-parameter-1-1> >". I'm trying to paste below the trees:

(gdb) p debug_tree(class_of_this_parm(t))
 <record_type 0x7ffff6819a80 X type_0 type_5 type_6 VOID
    size <integer_cst 0x7ffff66d58a0 type <integer_type 0x7ffff66d7150 
bitsizetype> constant 0>
    unit size <integer_cst 0x7ffff66d5858 type <integer_type 
0x7ffff66d70a8 sizetype> constant 0>
    align 8 symtab 0 alias set -1 canonical type 0x7ffff6819a80
    fields <type_decl 0x7ffff6813b80 X
        type <record_type 0x7ffff6819b28 X type_0 type_5 type_6 VOID 
size <integer_cst 0x7ffff66d58a0 0> unit size <integer_cst 0x7ffff66d5858 0>
            align 8 symtab 0 alias set -1 canonical type 0x7ffff6819a80 
fields <type_decl 0x7ffff6813b80 X> context <translation_unit_decl 
0x7ffff66e0170 D.1>
            full-name "struct X< <template-parameter-1-1> >"
            n_parents=0 use_template=0 interface-unknown
            chain <type_decl 0x7ffff6813a10 X>>
        used nonlocal decl_4 VOID file 57543_1.C line 5 col 1
        align 1 context <record_type 0x7ffff6819a80 X> result 
<record_type 0x7ffff6819a80 X>
       > context <translation_unit_decl 0x7ffff66e0170 D.1>
    full-name "struct X< <template-parameter-1-1> >"
    n_parents=0 use_template=0 interface-unknown
    pointer_to_this <pointer_type 0x7ffff6819d20> chain <type_decl 
0x7ffff6813a10 X>>
$3 = void
(gdb) p current_class_type
$4 = (tree) 0x7ffff682a2a0
(gdb) p debug_tree(current_class_type)
 <record_type 0x7ffff682a2a0 X type_5 type_6 VOID
    align 8 symtab 0 alias set -1 canonical type 0x7ffff682a2a0
    fields <type_decl 0x7ffff682c0b8 X
        type <record_type 0x7ffff682a348 X used type_5 type_6 VOID
            align 8 symtab 0 alias set -1 canonical type 0x7ffff682a2a0 
context <translation_unit_decl 0x7ffff66e0170 D.1>
            full-name "struct X<int>"
            n_parents=0 use_template=1 interface-unknown
            chain <type_decl 0x7ffff6813f18 X>>
        used external nonlocal suppress-debug decl_4 VOID file 
57543_1.C line 5 col 1
        align 8 context <record_type 0x7ffff682a2a0 X> result 
<record_type 0x7ffff682a2a0 X>
       > context <translation_unit_decl 0x7ffff66e0170 D.1>
    full-name "struct X<int>"
    n_parents=0 use_template=1 interface-unknown
    pointer_to_this <pointer_type 0x7ffff682a3f0> chain <type_decl 
0x7ffff6813f18 X>>