[Bug debug/57667] New: -femit-struct-debug-detailed

[Bug debug/57667] New: -femit-struct-debug-detailed

[evgeny.gavrin at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57667

            Bug ID: 57667
           Summary: -femit-struct-debug-detailed
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: evgeny.gavrin at hotmail dot com

Created attachment 30331
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30331&action=edit
file with direct and indirect calls of structs

-femit-struct-debug-detailed

[Bug debug/57667] -femit-struct-debug-detailed

[evgeny.gavrin at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57667

--- Comment #1 from Evgeny Gavrin <evgeny.gavrin at hotmail dot com> ---
Created attachment 30332
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30332&action=edit
structs declaration

[Bug debug/57667] -femit-struct-debug-detailed

[evgeny.gavrin at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57667

--- Comment #2 from Evgeny Gavrin <evgeny.gavrin at hotmail dot com> ---
Hi!

>From the documentation to -femit-struct-debug-detailed:
"The value `base' means that the base of name of the file in which the type
declaration appears must match the base of the name of the main compilation
file."

I've created two files test.c and test-nonbase.h. (attached)

So, as I understand, when compiling like "gcc-4.7 test.c -O0 -g2
-femit-struct-debug-detailed=ind:ord:base" info about structs declared in
test-nonbase.h shouldn't be emitted.

But I can get all debug info on structs declared in test-nonbase.h using gdb:
Starting program: ./gcc-tests/a.out 

Breakpoint 1, main () at test.c:18
18      free(indir_ord);
(gdb) p a
$1 = 5
(gdb) p b
$2 = 98
(gdb) p dir_ord 
$3 = {a = 5, b = 97 'a'}
(gdb) p *indir_ord 
$4 = {a = 10, b = 98 'b'}

Meanwhile, compiling with "-femit-struct-debug-detailed=ord:base" gdb can't
find the debug info:
Starting program: ./gcc-tests/a.out 

Breakpoint 1, main () at test.c:18
18      free(indir_ord);
(gdb) p dir_ord
$1 = <incomplete type>
(gdb) p *inddir_ord
No symbol "inddir_ord" in current context.
(gdb) p *indir_ord
$2 = <incomplete type>


Let's see the code:
./gcc/opts.c

  51 void
  52 set_struct_debug_option (struct gcc_options *opts, location_t loc,
  53                          const char *spec)
  54 {

*************

  62   /* Default is to apply to as much as possible. */
  63   enum debug_info_usage usage = DINFO_USAGE_NUM_ENUMS;
  64   int ord = 1, gen = 1;

*************

  96   if (usage == DINFO_USAGE_NUM_ENUMS)
  97     {
  98       if (ord)
  99         {
 100           opts->x_debug_struct_ordinary[DINFO_USAGE_DFN] = files;
 101           opts->x_debug_struct_ordinary[DINFO_USAGE_DIR_USE] = files;
 102           opts->x_debug_struct_ordinary[DINFO_USAGE_IND_USE] = files;
 103         }
 104       if (gen)
 105         {
 106           opts->x_debug_struct_generic[DINFO_USAGE_DFN] = files;
 107           opts->x_debug_struct_generic[DINFO_USAGE_DIR_USE] = files;
 108           opts->x_debug_struct_generic[DINFO_USAGE_IND_USE] = files;
 109         }
 110     }
 111   else
 112     {
 113       if (ord)
 114         opts->x_debug_struct_ordinary[usage] = files;
 115       if (gen)
 116         opts->x_debug_struct_generic[usage] = files;
 117     }

This means that first optional parameter shouldn't affect so much. In case it's
omitted debug info should be emitted both for [dir:] and [ind:], but only for
base files.

Two cases:
1) test.c -O0 -g2 -femit-struct-debug-detailed=ind:ord:base

    opts->x_debug_struct_ordinary[usage] = files;

2) test.c -O0 -g2 -femit-struct-debug-detailed=ord:base

    opts->x_debug_struct_ordinary[DINFO_USAGE_DFN] = files;
    opts->x_debug_struct_ordinary[DINFO_USAGE_DIR_USE] = files;
    opts->x_debug_struct_ordinary[DINFO_USAGE_IND_USE] = files;


The following "-femit-struct-debug-detailed=ind:ord:base" means that debug info
should be emitted for structs used indirectly and declared in file that matches
the base name of the compilation file (test.c/test.h).

So, in the particular case, when struct is used indirectly in test.c and
declared in test-nonbase.h - info on structs shouldn't be emitted.

In case of, "-femit-struct-debug-detailed=ord:base" - it works correctly and
emits nothing.

[Bug debug/57667] -femit-struct-debug-detailed

[evgeny.gavrin at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57667

--- Comment #3 from Evgeny Gavrin <evgeny.gavrin at hotmail dot com> ---
Command to run:
egavrin@debian:~/dev/vd-issues/ld-memory-consumption/gcc-tests$ gcc-4.7 test.c
-O0 -g2 -gdwarf-2 -femit-struct-debug-detailed=ind:ord:base
egavrin@debian:~/dev/vd-issues/ld-memory-consumption/gcc-tests$ gdb ./a.out 
*********
(gdb) b 18
Breakpoint 1 at 0x400593: file test.c, line 18.
(gdb) run
Starting program:
/home/egavrin/dev/vd-issues/ld-memory-consumption/gcc-tests/a.out 

Breakpoint 1, main () at test.c:18
18      free(indir_ord);
(gdb) p dir_ord
$1 = {a = 5, b = 97 'a'}
(gdb) p indir_ord
$2 = (struct IND_ORD *) 0x601010
(gdb) p *indir_ord
$3 = {a = 10, b = 98 'b'}
(gdb) 

egavrin@debian:~/dev/vd-issues/ld-memory-consumption/gcc-tests$ gcc-4.7 test.c
-O0 -g2 -gdwarf-2 -femit-struct-debug-detailed=ord:base
egavrin@debian:~/dev/vd-issues/ld-memory-consumption/gcc-tests$ gdb ./a.out 
GNU gdb (GDB) 7.4.1-debian
This GDB was configured as "x86_64-linux-gnu".
Reading symbols from
/home/egavrin/dev/vd-issues/ld-memory-consumption/gcc-tests/a.out...done.
(gdb) b 18
Breakpoint 1 at 0x400593: file test.c, line 18.
(gdb) run
Starting program:
/home/egavrin/dev/vd-issues/ld-memory-consumption/gcc-tests/a.out 

Breakpoint 1, main () at test.c:18
18      free(indir_ord);
(gdb) p dir_ord
$1 = <incomplete type>
(gdb) p indir_ord 
$2 = (struct IND_ORD *) 0x601010
(gdb) p *indir_ord 
$3 = <incomplete type>