Compiling a .cpp file with the following contents triggers an internal compiler
error:
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
struct Base {
template<class Cvoid method() { }
};
struct Left : public Base { };
struct Right : public Base { };
struct Join : public Left, public Right { };
void function()
{
Join join;
join.Base::method<int>();
join.Left::method<int>();
}
Issued command-line:
g++ -Wall -W -Wundef -Wpointer-arith -g -c -o /dev/null bug.cpp
Resulting output:
bug.cpp: In function 'void function()':
bug.cpp:13: internal compiler error: in build_base_path, at cp/class.c:273
Please submit a full bug report,
The error does not occur if structs Left and Right inherit virtually from Base;
that is, "struct Left : virtual public Base { };" and similarly for Right.
The same error occurs with gcc-3.4.3, the only difference being that the
relevant line number in cp/class.cp is 275.
Full output from running with "-v " is as follows:
g++ -v -save-temps -Wall -W -Wundef -Wpointer-arith -g -c -o /dev/null
bug.cpp
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /gcc-4.1.1/configure
,c++
Thread model: posix
gcc version 4.1.1
/ -E -quiet -v
-D_GNU_SURCE bug.cpp -mtune=pentiumpro -Wall -W -Wundef -Wpointer-arith
-fworking-directory -fpch-preprocess -o bug.ii
ignoring nonexistent directory "NNE/include"
ignoring nonexistent directory
"/"
#include "" search starts here:
#include <search starts here:
/
/
/
/usr/local/include
/
/usr/include
End of search list.
/ -fpreprocessed bug.ii
-quiet -dumpbase bug.cpp -mtune=pentiumpro -auxbase-strip /dev/null -g
-Wall -W -Wundef -Wpointer-arith -version -o bug.s
GNU C++ version 4.1.1 (i686-pc-linux-gnu)
compiled by GNU C version 4.1.1.
GGC heuristics: ggc-min-expand=63 ggc-min-heapsize=63424
Compiler executable checksum:
bug.cpp: In function 'void function()':
bug.cpp:13: internal compiler error: in build_base_path, at cp/class.c:273
Please submit a full bug report,
with preprocessed source if appropriate.
See <for instructions.
Contents of bug.ii:
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
# 1 "bug.cpp"
# 1 "/home/raymond/tmp//"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "bug.cpp"
struct Base {
template<class Cvoid method() { }
};
struct Left : public Base { };
struct Right : public Base { };
struct Join : public Left, public Right { };
void function()
{
Join join;
join.Base::method<int>();
join.Left::method<int>();
}

Comment #1 from pinskia at gcc dot gnu dot org 2006-09-14 15:33
This is invalid code, 3.3.3 and before gave the following error:
t.cc: In function `void function()':
t.cc:13: error: `Base' is an ambiguous base of `Join'
Which is correct.

Also we don't get an ICE if we try with a non template function.

Comment #2 from raymond at corvil dot com 2006-09-14 15:58
Line 13 in the sample code is invalid code but line 14 is valid (Base is an
unambiguous base class of Left). Deleting line 13 leaves code that compiles
cleanly with gcc-3.3.5 (i386-portbld-freebsd4.8, gcc version 3.3.5 20040901
(prerelease) [FreeBSD]).

Apologies for any confusion, I meant to delete line 13 before submitting.

Comment #3 from bangerth at dealii dot org 2006-09-15 13:49
Confirmed. This is the valid testcase:

struct Base {
template<class Cvoid method() { }
};

struct Left : public Base { };
struct Right : public Base { };
struct Join : public Left, public Right { };

void function()
{
Join join;
join.Left::method<int>();
}

and this is what we get from 4.1 branch:

g/x/ -c x.cc
x.cc: In function 'void function()':
x.cc:12: internal compiler error: in build_base_path, at cp/class.c:273
Please submit a full bug report,
with preprocessed source if appropriate.
See <for instructions.

Comment #4 from steven at gcc dot gnu dot org 2006-09-23 15:19
Breakpoint 1, fancy_abort (file=0xde98b0 "//trunk/gcc/cp/class.c",
line=272,
function=0xde98a0 "build_base_path") at
642 internal_error ("in %s, at %s:%d", function, trim_filename (file),
line);
(gdb) up
#1 0x00000000004c328a in build_base_path (code=PLUS_EXPR, expr=0x2aaaaaf85340,
binfo=0x2aaaaaac19a0, nonnull=1) at //trunk/gcc/cp/class.c:269
269 gcc_assert ((code == MINUS_EXPR
(gdb) l
264
265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
266 if (want_pointer)
267 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
268
269 gcc_assert ((code == MINUS_EXPR
270 && SAME_BINFTYPE_P (BINFTYPE (binfo), probe))
271 || (code == PLUS_EXPR
272 && SAME_BINFTYPE_P (BINFTYPE (d_binfo), probe)));
273
(gdb) p code
$1 = PLUS_EXPR
(gdb)
(gdb) p probe
$2 = (tree) 0x2aaaaaf7db00
(gdb) p debug_tree(probe)
<record_type 0x2aaaaaf7db00 Join type_1 type_5 HI
size <integer_cst 0x2aaaaadf09c0 type <integer_type 0x2aaaaae030b0
bit_size_typeconstant invariant 16>
unit size <integer_cst 0x2aaaaadf09f0 type <integer_type 0x2aaaaae03000
long unsigned intconstant invariant 2>
align 8 symtab 0 alias set -1
fields <type_decl 0x2aaaaaf87000 Join type <record_type 0x2aaaaaf7db00
Join>
nonlocal decl_4 VID file t.C line 7
align 1 context <record_type 0x2aaaaaf7db00 Join>
>
X() X(constX&) this=(X&) n_parents=2 use_template=0 interface-unknown
pointer_to_this <pointer_type 0x2aaaaaf7ddc0chain <type_decl
0x2aaaaaf20dd0 Join>>
$3 = void
(gdb) p debug_tree(d_binfo)
<tree_binfo 0x2aaaaaac1930
type <record_type 0x2aaaaaf7d840 Left type_1 type_5 QI
size <integer_cst 0x2aaaaadf07b0 constant invariant 8>
unit size <integer_cst 0x2aaaaadf07e0 constant invariant 1>
align 8 symtab 0 alias set -1
fields <type_decl 0x2aaaaaf20d00 Left type <record_type 0x2aaaaaf7d840
Left>
nonlocal decl_4 VID file t.C line 5
align 1 context <record_type 0x2aaaaaf7d840 Left>
>
X() X(constX&) this=(X&) n_parents=1 use_template=0 interface-unknown
chain <type_decl 0x2aaaaaf20c30 Left>>
private>
$4 = void
(gdb) p d_binfo->common.type
$5 = (tree) 0x2aaaaaf7d840
(gdb) p debug_tree(d_binfo->common.type)
<record_type 0x2aaaaaf7d840 Left type_1 type_5 QI
size <integer_cst 0x2aaaaadf07b0 type <integer_type 0x2aaaaae030b0
bit_size_typeconstant invariant 8>
unit size <integer_cst 0x2aaaaadf07e0 type <integer_type 0x2aaaaae03000
long unsigned intconstant invariant 1>
align 8 symtab 0 alias set -1
fields <type_decl 0x2aaaaaf20d00 Left type <record_type 0x2aaaaaf7d840
Left>
nonlocal decl_4 VID file t.C line 5
align 1 context <record_type 0x2aaaaaf7d840 Left>
>
X() X(constX&) this=(X&) n_parents=1 use_template=0 interface-unknown
chain <type_decl 0x2aaaaaf20c30 Left>>
$6 = void
(gdb)

Comment #5 from mmitchel at gcc dot gnu dot org 2006-10-02 04:12
Subject: Bug 29080

Author: mmitchel
Date: Mon 2 04:12:30 2006
New Revision: 117360

URL:
Log:
PR c++/29080
* parser.c (): Use
BASELINK_ACCESS_BINF as the qualifying scope when calling

PR c++/29080
* gdg/template/member7.C: New test.

Added:

Modified:
trunk/gcc/cp/ChangeLog
trunk/gcc/cp/parser.c
trunk/gcc/testsuite/ChangeLog

Comment #6 from mmitchel at gcc dot gnu dot org 2006-10-02 04:51
Subject: Bug 29080

Author: mmitchel
Date: Mon 2 04:51:28 2006
New Revision: 117363

URL:
Log:
PR c++/29080
* parser.c (): Use
BASELINK_ACCESS_BINF as the qualifying scope when calling

PR c++/29080
* gdg/template/member7.C: New test.

Added:

Modified:

Comment #7 from gdr at gcc dot gnu dot org 2007-02-03 20:15
Fixed in GCC-4.1.2.