Tested on: GNU C++ 4.4.0 20090323 (experimental)
Testcase:
------------------------------------------------------------------------------
namespace A
{
static int var2 = 2;
}
int
func (void)
{
using A::var2;
return var2;
}
------------------------------------------------------------------------------
will generate (reduced):
<1><2d>: Abbrev Number: 2 (DW_TAG_subprogram)
<2f> DW_AT_name : (indirect string, offset: 0x42): func
<3d> DW_AT_low_pc : 0x0
<45> DW_AT_high_pc : 0xc
<4d> DW_AT_frame_base : 0x0 (location list)
<2><55>: Abbrev Number: 3 (DW_TAG_lexical_block)
<56> DW_AT_low_pc : 0x4
<5e> DW_AT_high_pc : 0xa
<3><66>: Abbrev Number: 4 (DW_TAG_imported_declaration)
<69> DW_AT_import : <0x7f> [Abbrev Number: 7 (DW_TAG_variable)]
<1><76>: Abbrev Number: 6 (DW_TAG_namespace)
<77> DW_AT_name : A
<2><7f>: Abbrev Number: 7 (DW_TAG_variable)
<80> DW_AT_name : (indirect string, offset: 0x34): var2
<84> DW_AT_decl_file : 1
<85> DW_AT_decl_line : 3
<86> DW_AT_type : <0x6f>
<8a> DW_AT_declaration : 1
<2><8b>: Abbrev Number: 7 (DW_TAG_variable)
<8c> DW_AT_name : (indirect string, offset: 0x34): var2
<84> DW_AT_decl_file : 1
<85> DW_AT_decl_line : 3
<92> DW_AT_type : <0x6f>
<96> DW_AT_declaration : 1
<1><98>: Abbrev Number: 8 (DW_TAG_variable)
<99> DW_AT_specification: <0x8b>
<9d> DW_AT_location : 9 byte block: 3 0 0 0 0 0 0 0 0 (DW_OP_addr: 0)
You can see the code references the <7f> "var" instance but DW_AT_location is
given by the <98> completion only for the <8b> "var" instance.
Also <7f> and <8b> have a name conflict as being in the same naming scope.
This problem causes a wrong evaluation by Archer archer-keiths-expr-cumulative
branch (which is IMO right) for the more complex testcase - as it cannot find
the right DW_AT_location there:
------------------------------------------------------------------------------
# archer-keiths-expr-cumulative=35ca449e9f1a4cd477df644f717bbe4e3362c486/gdb -q
./outer
(gdb) l 1
1 #include <stdlib.h>
2
3 namespace A
4 {
5 static int var = 2;
6 }
7
8 int
9 main (void)
10 {
11 int var = 1;
12
13 if (var != 1) /* var-is-1 */
14 abort ();
15
16 {
17 using A::var;
18
19 if (var != 2) /* var-is-2 */
20 abort ();
21 }
22
23 return 0; /* break-here */
24 }
(gdb) b 13
Breakpoint 1 at 0x4005a7: file outer.C, line 13.
(gdb) r
Starting program: /tmp/outer
Breakpoint 1, main () at outer.C:13
13 if (var != 1) /* var-is-1 */
(gdb) p var
$1 = 1
(gdb) adv 19
main () at outer.C:19
19 if (var != 2) /* var-is-2 */
(gdb) p var
$2 = 1
^^^^^^ Wrong GDB evaluation.
(gdb) adv 23
main () at outer.C:23
23 return 0; /* break-here */
(gdb) q
------------------------------------------------------------------------------
--
Summary: Duplicite C++ DW_TAG_variable breaking its
DW_AT_location resolution
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jan dot kratochvil at redhat dot com
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39524
