Compiler's -xs switch

Question

We just switched to studio12 and I think we are having problems with the
compiler/linker switch -xs which detemines whether the debug info is
saved in the object or in the (in our case) library. We see this when
compiling/linking on both SunAMD and sun sparc.
In studio11 our shared library size changed by a factor of 10 depending on
whether or not the -xs switch was used.
IN STUDIO11
Studio 11 - debug library without '-xs' switch
ls -lt /cm/iqa/d_objs/SunAMD64/libs/debug64/libiq15.so.1
-rwxrwxr-x 1 noname nogroup 57,318,264 Dec 15 12:36 libx.so.1*
     Studio 11 - debug library without '-xs' switch
ls -lt /cm/iqa/d_objs/SunAMD64/libs/debug64/libiq15.so.1
-rwxrwxr-x 1 noname nogroup 555,941,656 Dec 15 13:13 libx.so.1*
=====================================
STUDIO 12
In studio12 the size of the library is the same with or
without the use of the -xs switch
studio12 - no "-xs switch"
ls -lt /cm/iqa/d_objs/SunAMD64/libs/debug64/libiq15.so.1
-rwxrwxr-x 1 noname nogroup 587,676,248 Dec 15 13:45 libx.so.1*
with -xs switch
ls -lt /cm/iqa/d_objs/SunAMD64/libs/debug64/libiq15.so.1
-rwxrwxr-x 1 noname nogroup 587,678,528 Dec 15 14:38 libx.so.1*
Are we missing something when we compile/link in studio12 ?
Thanks,
tom

Answer 1

The amount of debug data depends on the number and kind of declarations in the compilation unit. C++ programs typically include a lot of standard headers with lots of declarations, so there is a lot of debug data. DWARF debug data is much larger than stabs, so the size of a C++ object file compiled with -g will be larger with Studio 12 than with Studio 11.
But the debug data is in a program section that is not loaded into memory unless you use a debugger or similar tool to access it. So you use more disk space, but not necessarily address space in the running program.