When I compile a program that uses pointers to member functions, GCC emits
DWARF claiming that the pmf has the type 'struct { X (*__pfn)(Y); int __delta
}'. I would expect it to produce a DW_TAG_ptr_to_member_type DIE whose
DW_AT_type attribute was a function type.
I've checked that this problem exists in the current head (r157312).
To reproduce:
$ cat mp.ii
struct S {
int b;
int foo(int x) { return b+x; }
};
int f(S &s, int (S::*pimf)(int)) { return (s.*pimf)(42); }
$ with-my-gcc g++ --version
g++ (GCC) 4.5.0 20100309 (experimental)
Copyright (C) 2010 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ with-my-gcc g++ -c -g mp.ii
$ readelf -wi mp.o
Contents of the .debug_info section:
Compilation Unit @ offset 0x0:
Length: 0xe7 (32-bit)
Version: 2
Abbrev Offset: 0
Pointer Size: 4
<0><b>: Abbrev Number: 1 (DW_TAG_compile_unit)
< c> DW_AT_producer : (indirect string, offset: 0x24): GNU C++ 4.5.0
20100309 (experimental)
<10> DW_AT_language : 4 (C++)
<11> DW_AT_name : (indirect string, offset: 0x72): mp.ii
<15> DW_AT_comp_dir : (indirect string, offset: 0x0):
/home/jimb/play/cpp-member-pointers
<19> DW_AT_low_pc : 0x0
<1d> DW_AT_high_pc : 0x3d
<21> DW_AT_stmt_list : 0x0
<1><25>: Abbrev Number: 2 (DW_TAG_structure_type)
<26> DW_AT_name : S
<28> DW_AT_byte_size : 4
<29> DW_AT_decl_file : 1
<2a> DW_AT_decl_line : 1
<2b> DW_AT_sibling : <0x59>
<2><2f>: Abbrev Number: 3 (DW_TAG_member)
<30> DW_AT_name : b
<32> DW_AT_decl_file : 1
<33> DW_AT_decl_line : 2
<34> DW_AT_type : <0x59>
<38> DW_AT_data_member_location: 2 byte block: 23 0
(DW_OP_plus_uconst: 0)
<2><3b>: Abbrev Number: 4 (DW_TAG_subprogram)
<3c> DW_AT_external : 1
<3d> DW_AT_name : foo
<41> DW_AT_decl_file : 1
<42> DW_AT_decl_line : 3
<43> DW_AT_MIPS_linkage_name: (indirect string, offset: 0x66):
_ZN1S3fooEi
<47> DW_AT_type : <0x59>
<4b> DW_AT_declaration : 1
<3><4c>: Abbrev Number: 5 (DW_TAG_formal_parameter)
<4d> DW_AT_type : <0x60>
<51> DW_AT_artificial : 1
<3><52>: Abbrev Number: 6 (DW_TAG_formal_parameter)
<53> DW_AT_type : <0x59>
<1><59>: Abbrev Number: 7 (DW_TAG_base_type)
<5a> DW_AT_byte_size : 4
<5b> DW_AT_encoding : 5 (signed)
<5c> DW_AT_name : int
<1><60>: Abbrev Number: 8 (DW_TAG_pointer_type)
<61> DW_AT_byte_size : 4
<62> DW_AT_type : <0x25>
<1><66>: Abbrev Number: 9 (DW_TAG_subprogram)
<67> DW_AT_external : 1
<68> DW_AT_name : f
<6a> DW_AT_decl_file : 1
<6b> DW_AT_decl_line : 6
<6c> DW_AT_MIPS_linkage_name: (indirect string, offset: 0x52):
_Z1fR1SMS_FiiE
<70> DW_AT_type : <0x59>
<74> DW_AT_low_pc : 0x0
<78> DW_AT_high_pc : 0x3d
<7c> DW_AT_frame_base : 0x0 (location list)
<80> DW_AT_sibling : <0x9f>
<2><84>: Abbrev Number: 10 (DW_TAG_formal_parameter)
<85> DW_AT_name : s
<87> DW_AT_decl_file : 1
<88> DW_AT_decl_line : 6
<89> DW_AT_type : <0x9f>
<8d> DW_AT_location : 2 byte block: 91 0 (DW_OP_fbreg: 0)
<2><90>: Abbrev Number: 11 (DW_TAG_formal_parameter)
<91> DW_AT_name : (indirect string, offset: 0x61): pimf
<95> DW_AT_decl_file : 1
<96> DW_AT_decl_line : 6
<97> DW_AT_type : <0xaa>
<9b> DW_AT_location : 2 byte block: 91 4 (DW_OP_fbreg: 4)
<1><9f>: Abbrev Number: 12 (DW_TAG_const_type)
<a0> DW_AT_type : <0xa4>
<1><a4>: Abbrev Number: 13 (DW_TAG_reference_type)
<a5> DW_AT_byte_size : 4
<a6> DW_AT_type : <0x25>
<1><aa>: Abbrev Number: 14 (DW_TAG_structure_type)
<ab> DW_AT_byte_size : 8
<ac> DW_AT_decl_file : 2
<ad> DW_AT_decl_line : 0
<ae> DW_AT_sibling : <0xcf>
<2><b2>: Abbrev Number: 15 (DW_TAG_member)
<b3> DW_AT_name : (indirect string, offset: 0x78): __pfn
<b7> DW_AT_decl_file : 1
<b8> DW_AT_decl_line : 6
<b9> DW_AT_type : <0xe4>
<bd> DW_AT_data_member_location: 2 byte block: 23 0
(DW_OP_plus_uconst: 0)
<2><c0>: Abbrev Number: 15 (DW_TAG_member)
<c1> DW_AT_name : (indirect string, offset: 0x4a): __delta
<c5> DW_AT_decl_file : 1
<c6> DW_AT_decl_line : 6
<c7> DW_AT_type : <0x59>
<cb> DW_AT_data_member_location: 2 byte block: 23 4
(DW_OP_plus_uconst: 4)
<1><cf>: Abbrev Number: 16 (DW_TAG_subroutine_type)
<d0> DW_AT_type : <0x59>
<d4> DW_AT_sibling : <0xe4>
<2><d8>: Abbrev Number: 5 (DW_TAG_formal_parameter)
<d9> DW_AT_type : <0x60>
<dd> DW_AT_artificial : 1
<2><de>: Abbrev Number: 6 (DW_TAG_formal_parameter)
<df> DW_AT_type : <0x59>
<1><e4>: Abbrev Number: 8 (DW_TAG_pointer_type)
<e5> DW_AT_byte_size : 4
<e6> DW_AT_type : <0xcf>
$
--
Summary: G++ emits bad DWARF for pointers to member functions
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jimb at red-bean dot com
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43312
