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gcc 3.4 regression in gdb.cp/namespace.exp
- From: David Carlton <carlton at kealia dot com>
- To: gdb <gdb at sources dot redhat dot com>
- Cc: Daniel Jacobowitz <drow at mvista dot com>
- Date: Mon, 15 Mar 2004 16:23:41 -0800
- Subject: gcc 3.4 regression in gdb.cp/namespace.exp
I just ran the testsuite with g++ (GCC) 3.5.0 20040119 (experimental)
(which is right after 3.4 branched), and I get a regression on
gdb.cp/namespace.exp, on both mainline and 6.1.
ptype CClass::NestedClass
There is no field named NestedClass
(gdb) FAIL: gdb.cp/namespace.exp: ptype CClass::NestedClass
Just to double-check, I reverted my recent dwarf2read.c patch (I
tested in with that GCC a week ago, but who knows), and it still
fails. Daniel, might it be an issue with a recent patch of yours? (I
have a more specific guess below.)
Here's some more info: the classes in question are defined as follows:
class CClass {
public:
int x;
class NestedClass {
public:
int y;
};
};
The debug info that I'm getting looks like this:
.uleb128 0x17 # (DIE (0x480) DW_TAG_structure_type)
.long 0x505 # DW_AT_sibling
.long .LASF2 # DW_AT_name: "CClass"
.byte 0x1 # DW_AT_declaration
.uleb128 0x18 # (DIE (0x48a) DW_TAG_structure_type)
.long .LASF1 # DW_AT_name: "NestedClass"
.byte 0x4 # DW_AT_byte_size
.byte 0x1 # DW_AT_decl_file
.byte 0x5e # DW_AT_decl_line
.uleb128 0x8 # (DIE (0x492) DW_TAG_member)
.ascii "y\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file
.byte 0x60 # DW_AT_decl_line
.long 0x19e # DW_AT_type
.byte 0x2 # DW_AT_data_member_location
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x0
(Rest of CClass::NestedClass definition omitted.) Then, later on, we
see:
.uleb128 0x7 # (DIE (0x6ec) DW_TAG_structure_type)
.long 0x75d # DW_AT_sibling
.long 0x480 # DW_AT_specification
.byte 0x4 # DW_AT_byte_size
.byte 0x1 # DW_AT_decl_file
.byte 0x5b # DW_AT_decl_line
.uleb128 0x8 # (DIE (0x6f8) DW_TAG_member)
.ascii "x\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file
.byte 0x5d # DW_AT_decl_line
.long 0x19e # DW_AT_type
.byte 0x2 # DW_AT_data_member_location
.byte 0x23 # DW_OP_plus_uconst
.uleb128 0x0
(Rest of CClass definition omitted.)
So we have a die giving a declaration for CClass which in turn
contains a die giving a definition for CClass::NestedClass. Which in
turn suggests that the loop in process_structure_scope should be run
even if the current DIE is a declaration.
I'll fiddle around with an appropriate patch either later today or
tommorow.
I really hate the way we test our DWARF 2 reader - there's no way to
generate the debug info by hand to give a particular scenario, so
instead we have to hope that we can find the magic version of GCC and
magic way of writing a test case to trigger the bug in question.
Sigh.
David Carlton
carlton@kealia.com