[Bug c++/11834] New: [3.4 regression] template specialization not matched

[Bug c++/11834] New: [3.4 regression] template specialization not matched

[bangerth at dealii dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834

           Summary: [3.4 regression] template specialization not matched
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: critical
          Priority: P1
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bangerth at dealii dot org
                CC: gcc-bugs at gcc dot gnu dot org

Here's something I extracted from boost, and which breaks my nightly
builds:
---------------------------------
template <typename T0> struct tuple {
    typedef tuple<int> tail;
};

template <> struct tuple<int> {};

template <typename L>
struct length  {
    static const int i = length<typename L::tail>::i;
};

template<>
struct length<tuple<int> > {
    static const int i = 0;
};


template <typename L, int = length<L>::i> struct M {};


template <typename C, typename A>
M<tuple<A> > foo (void (C::*)(A));

template <typename C, typename A>
M<tuple<A> > foo (void (C::*)(A) const);


struct S { void f(int) const; };

void bar() {
  foo (&S::f);
}
----------------------------------------

g/x> /home/bangerth/bin/gcc-3.4-pre/bin/c++ -c y.cc -ftemplate-depth-4
y.cc: In instantiation of `length<typename tuple<A>::tail::tail::tail>':
y.cc:9:   instantiated from `length<typename tuple<A>::tail::tail>'
y.cc:9:   instantiated from `length<typename tuple<A>::tail>'
y.cc:9:   instantiated from `length<tuple<A> >'
y.cc:31:   instantiated from here
y.cc:9: error: incomplete type `length<typename
   tuple<A>::tail::tail::tail::tail>' used in nested name specifier

(Note that one should limit the template depth to avoid excessive screen
clutter and keep computing time reasonable.)

The error is entirely spurious: the return type of foo is 
M<tuple<int>,1>, where the second template argument of M is
deduced using length<tuple<int> >::i, which should use the
specialization of length. Even if it didn't, then the recusion
should hit the specialization in the next round, but it doesn't.

Note that the bug goes mysteriously away if I remove either
of the two foo() functions. That doesn't make much sense, since
only the second one should match the call in bar() anyway, but
that's another bug which I reported a long time ago, see PR 8271.

W.

[Bug c++/11834] [3.4 regression] template specialization not matched

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|0000-00-00 00:00:00         |2003-08-06 15:33:46
               date|                            |


------- Additional Comments From pinskia at physics dot uc dot edu  2003-08-06 15:33 -------
Well it now hangs at least on powerpc on the mainline (20030806):
(gdb) bt
#0  resolve_typename_type (type=0x4f73f0, only_current_p=true) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:11783
... (up to 57 resolve_typename_type and then some other junk).
#678 0x00017aac in lookup_qualified_name (scope=0x4efd90, name=0x412648c0, 
is_type_p=false, complain=false) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/
cp/decl.c:5794
#679 0x00035e68 in tsubst_qualified_id (qualified_id=0xbfffe660, args=0x4efd90, complain=3, 
in_decl=0x412648c0, done=1093035664, address_p=1093035664) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:7124
#680 0x000381ec in tsubst_copy_and_build (t=0x0, args=0xbfffe660, complain=3, in_decl=0x0, 
function_p=1093028032) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/
pt.c:8044
#681 0x000331b4 in instantiate_class_template (type=0x4efd90) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:5305
#682 0x0006c85c in complete_type (type=0x0) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-
clean/src/gcc/cp/typeck.c:135
#683 0x00083c18 in lookup_member (xbasetype=0x41204610, name=0x0, protect=0, 
want_type=1093028032) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/
search.c:1252
#684 0x00017aac in lookup_qualified_name (scope=0x41269540, name=0x412648c0, 
is_type_p=false, complain=false) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/
cp/decl.c:5794
#685 0x00035e68 in tsubst_qualified_id (qualified_id=0xbfffe920, args=0x41269540, 
complain=tf_none, in_decl=0x412648c0, done=1093035664, address_p=1093035664) at /
Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:7124
#686 0x000381ec in tsubst_copy_and_build (t=0x0, args=0xbfffe920, complain=tf_none, 
in_decl=0x0, function_p=1093028032) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/
gcc/cp/pt.c:8044
#687 0x000332ac in tsubst_template_arg (t=0x40dbabe0, args=0x41269380, complain=tf_none, 
in_decl=0x0) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:5459
#688 0x000333e8 in tsubst_template_args (t=0x0, args=0x4f0018, complain=4718592, 
in_decl=0x41266690) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:5519
#689 0x000337f0 in tsubst_aggr_type (t=0x41267af8, args=0xbfffead0, complain=1093040788, 
in_decl=0x1, entering_scope=-1073747680) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-
clean/src/gcc/cp/pt.c:5643
#690 0x00034680 in tsubst_function_type (t=0x41267af8, args=0x41267a94, 
complain=3221219616, in_decl=0x1) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/
gcc/cp/pt.c:6299
#691 0x0003544c in tsubst (t=0x41269e00, args=0x4f0018, complain=tf_none, in_decl=0x0) at 
/Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:6814
#692 0x00038de0 in fn_type_unification (fn=0x0, explicit_targs=0x4f0018, targs=0x480000, 
args=0x524ca8, return_type=0x41266690, strict=4718592, len=4718592) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:8643
#693 0x0003ad08 in get_bindings_real (fn=0x0, decl=0x4f0018, explicit_args=0x41269e00, 
check_rettype=4718592, deduce=5393576, len=1093035664) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:10007
#694 0x0003ab9c in more_specialized (pat1=0x41269700, pat2=0x480000, deduce=0, 
len=1093049856) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/pt.c:9914
#695 0x0000c5d8 in joust (cand1=0x524ca8, cand2=0x41266690, warn=false) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/call.c:5719
#696 0x0000c77c in tourney (candidates=0x41269e00) at /Volumes/UFS_Partition/pinskia/src/
fsf/gcc-clean/src/gcc/cp/call.c:5848
#697 0x00006cb0 in build_new_function_call (fn=0x41269700, args=0x4f0018) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/call.c:2715
#698 0x000882d0 in finish_call_expr (fn=0x4125dbb0, args=0x4126b918, 
disallow_virtual=4718592) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/
semantics.c:1683
#699 0x0005d698 in cp_parser_postfix_expression (parser=0x480000, address_p=4718592) at /
Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:3530
#700 0x0005dfac in cp_parser_unary_expression (parser=0x4126b918, address_p=1093049856) 
at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:4073
#701 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x3874a4, fn=0x480000 <lang_hooks+56>) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#702 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x3874bc, fn=0x5e9c8 <cp_parser_pm_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#703 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x3874dc, fn=0x5e9dc <cp_parser_multiplicative_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#704 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x3874f4, fn=0x5e9f0 <cp_parser_additive_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#705 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x38750c, fn=0x5ea04 <cp_parser_shift_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#706 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x387544, fn=0x5ea18 <cp_parser_relational_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#707 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x38755c, fn=0x5ea2c <cp_parser_equality_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#708 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x38756c, fn=0x5ea40 <cp_parser_and_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#709 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x38757c, fn=0x5ea54 <cp_parser_exclusive_or_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#710 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x38758c, fn=0x5ea68 <cp_parser_inclusive_or_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#711 0x000674e4 in cp_parser_binary_expression (parser=0x41262bd0, 
token_tree_map=0x38759c, fn=0x5ea7c <cp_parser_logical_and_expression>) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13122
#712 0x0005eb88 in cp_parser_assignment_expression (parser=0x41262bd0) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:4820
#713 0x0005ee30 in cp_parser_expression (parser=0x41262bd0) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:4968
#714 0x0005f2f4 in cp_parser_expression_statement (parser=0x0, in_statement_expr_p=true) at 
/Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:5250
#715 0x0005efb8 in cp_parser_statement (parser=0x41262bd0, in_statement_expr_p=false) at /
Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:5160
#716 0x0005f41c in cp_parser_statement_seq_opt (parser=0x41262bd0, 
in_statement_expr_p=false) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/
parser.c:5315
#717 0x0005f3ac in cp_parser_compound_statement (parser=0x41262bd0, 
in_statement_expr_p=false) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/
parser.c:5288
#718 0x00064d94 in cp_parser_ctor_initializer_opt_and_function_body (parser=0x4126b768) at /
Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:10721
#719 0x000679c4 in cp_parser_function_definition_after_declarator (parser=0x41262bd0, 
inline_p=false) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13420
#720 0x00067904 in cp_parser_function_definition_from_specifiers_and_declarator 
(parser=0x41262bd0, decl_specifiers=0x41269380, attributes=0x0, declarator=0x0) at /
Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:13366
#721 0x000636e4 in cp_parser_init_declarator (parser=0x41262bd0, 
decl_specifiers=0x4126b690, prefix_attributes=0x4f0018, 
function_definition_allowed_p=1093035664, member_p=false, function_definition_p=0xbffff7d0) 
at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:9228
#722 0x00060134 in cp_parser_simple_declaration (parser=0x4126b6c0, 
function_definition_allowed_p=1092954392) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-
clean/src/gcc/cp/parser.c:6106
#723 0x0005ffe8 in cp_parser_block_declaration (parser=0x41252918, 
statement_p=1093056192) at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/
parser.c:6023
#724 0x0005fe74 in cp_parser_declaration (parser=0x41262bd0) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:5943
#725 0x0005fce0 in cp_parser_declaration_seq_opt (parser=0x41262bd0) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:5852
#726 0x0005c12c in cp_parser_translation_unit (parser=0x41262bd0) at /Volumes/UFS_Partition/
pinskia/src/fsf/gcc-clean/src/gcc/cp/parser.c:2136
#727 0x00068c00 in c_parse_file () at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/
cp/parser.c:14308
#728 0x000b23f4 in c_common_parse_file (set_yydebug=1092634128) at /Volumes/
UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/c-opts.c:1205
#729 0x000cc590 in compile_file () at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/
toplev.c:1785
#730 0x000d1920 in do_compile () at /Volumes/UFS_Partition/pinskia/src/fsf/gcc-clean/src/gcc/
toplev.c:4587
#731 0x000d1a54 in toplev_main (argc=14, argv=0xbffffbf4) at /Volumes/UFS_Partition/pinskia/
src/fsf/gcc-clean/src/gcc/toplev.c:4628
#732 0x00002308 in _start (argc=14, argv=0xbffffbf4, envp=0xbffffbf4) at /SourceCache/Csu/
Csu-45/crt.c:267
#733 0x00002188 in start ()
Then this would make sense why Phil's regression hunter was not working.

[Bug c++/11834] [3.4 regression] template specialization not matched

[bangerth at ices dot utexas dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834



------- Additional Comments From bangerth at ices dot utexas dot edu  2003-08-06 18:22 -------
Subject: Re:  [3.4 regression] template specialization not matched


> Well it now hangs at least on powerpc on the mainline (20030806):

Did you try the -ftemplate-depth-5 thing? I noticed that my preprocessed 
sources take forever, until I realized that in our makefiles we limit the 
template depth. Maybe that is the reason why you think it hangs in your case.

W.

-------------------------------------------------------------------------
Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
                               www: http://www.ices.utexas.edu/~bangerth/

[Bug c++/11834] [3.4 regression] template specialization not matched

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-valid-code           |rejects-valid


------- Additional Comments From pinskia at physics dot uc dot edu  2003-08-06 18:30 -------
After Wolfgang suggestion of using -ftemplate-depth-5 I was able to use Phil's regression hunter: 
Search converges between 2003-07-07-trunk (#336) and 2003-07-08-trunk (#337).

Looks like gcc is not picking up the template specialization of the classes.

[Bug c++/11834] [3.4 regression] template specialization not matched

[janis187 at us dot ibm dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834


janis187 at us dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mmitchel at gcc dot gnu dot
                   |                            |org


------- Additional Comments From janis187 at us dot ibm dot com  2003-08-06 21:10 -------
The regression in PR 11834 was introduced or exposed by this patch:

--- gcc/gcc/cp/ChangeLog ---

2003-07-07  Mark Mitchell  <mark@codesourcery.com>

        * cp-tree.h (build_scoped_method_call): Remove.
        (lookup_qualified_name): Remove parameter.
        (tsubst_copy_and_build): Declare.
        [lots more]

The regression hunt took place on i686-pc-linux-gnu using the submitter's
test case compiled with -ftemplate-depth-5.

[Bug c++/11834] [3.4 regression] template specialization not matched

[cvs-commit at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834



------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-08-21 05:50 -------
Subject: Bug 11834

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	mmitchel@gcc.gnu.org	2003-08-21 05:50:54

Modified files:
	gcc/cp         : ChangeLog pt.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/template: deduce2.C 

Log message:
	PR c++/11834
	* pt.c (more_specialized): Bump processing_template_decl.
	
	PR c++/11834
	* g++.dg/template/deduce2.C: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.3615&r2=1.3616
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&r1=1.762&r2=1.763
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2985&r2=1.2986
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/deduce2.C.diff?cvsroot=gcc&r1=NONE&r2=1.1

[Bug c++/11834] [3.4 regression] template specialization not matched

[mmitchel at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11834


mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


------- Additional Comments From mmitchel at gcc dot gnu dot org  2003-08-21 05:54 -------
Fixed in GCC 3.4.