-g3 currently produces huge objects as it contains many unused macros.
-g2 produces no macros debug info so GDB cannot provide its expansion.
There is no way to store just the used macros.
(debuginfo compression driven by Roland McGrath may eliminate them but
still...)
While even a macro never used by a program can be helpful in most cases IMO it
is enough to provide the macro definitions touched by the code being debugged.
-feliminate-unused-debug-symbols -feliminate-unused-debug-types have no effect.
-------------------------------------------------------------------------------
#define NOT used
#define USED(x) x
int main (void) { return USED (0); }
-------------------------------------------------------------------------------
Getting:
gcc -g3 -o unusedmacro unusedmacro.c -Wall; readelf -wm unusedmacro
DW_MACINFO_define - lineno : 1 macro : NOT used
DW_MACINFO_define - lineno : 2 macro : USED(x) x
or:
gcc -g2 -o unusedmacro unusedmacro.c -Wall; readelf -wm unusedmacro
<nothing printed>
Expected output:
gcc -g3 -o unusedmacro unusedmacro.c -Wall; readelf -wm unusedmacro
DW_MACINFO_define - lineno : 2 macro : USED(x) x
--
Summary: DWARF .debug_macinfo contains unused macros
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: minor
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=42065
