------- Additional Comments From mark at codesourcery dot com 2005-07-22 23:43
-------
Subject: Re: [4.0 Regression] debug info omitted for uninitialized
variables
Devang Patel wrote:
>
> $ gdb --batch -x gdbcmds t
> Reading symbols for shared libraries ... done
> Breakpoint 1 at 0x2d14: file t.c, line 6.
> type = <unknown type>
> type = <unknown type>
> $1 = <unknown type>
> $2 = <unknown type>
>
> This is on powerpc-darwin. I expected this patch to fix this. Am I
> missing something ?
First, your example was not the one in the original bug report.
Second, you're using STABS, not DWARF-2. I suspect the stabs debug
generator, or the GDB stabs reader is not as good as DWARF.
On GNU/Linux, GDB knows that "bar" has type "int". It still doesn't
know the type of "foo"; apparently too much of the debug information is
optimized away. But, that's some other problem -- perhaps in GDB
itself. The information is clearly there for it:
.uleb128 0x2 # (DIE (0x2d) DW_TAG_variable)
.ascii "foo\0" # DW_AT_name
.byte 0x1 # DW_AT_decl_file
.byte 0x1 # DW_AT_decl_line
.long 0x38 # DW_AT_type
.uleb128 0x3 # (DIE (0x38) DW_TAG_base_type)
.ascii "int\0" # DW_AT_name
.byte 0x4 # DW_AT_byte_size
.byte 0x5 # DW_AT_encoding
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21828
