[lug] glibc-debuginfo...Help.

[D. Stimits]

Zan Lynx wrote:
> On Tue, 2005-04-12 at 15:01 -0600, Matt Thompson wrote:
> 
>>OK, in order to debug a problem I have with abiword on my FC3 box, I was
>>asked to install the glibc-debuginfo packages so that gdb works better,
>>I guess.
>>
>>Installing it is no problem, but I was wondering what happens to my
>>system with that there.  All of the sudden, will all my programs load up
>>a mess of debug information?  That is, will Firefox and Evolution be
>>larger than they usually are?

I wish I knew more about the debug info separation mentioned below, but 
maybe this will give *some* help in general.

The program can contain debug info, but have no debug info for linked 
libraries. In this case, the linked libraries are normal size, the main 
program is larger. In that case, if the error is in a library you won't 
know where, all you will know is which stack frame called the library. 
The reverse can be done, the libraries could contain debug info, and the 
main program not...in which case you could know exactly where in a 
library your crash starts, but not necessarily how you got there 
(libraries would enlarge, main program would stay the same size...of 
course any library functions called would consume more ram). I think 
most developers compile debug versions of their own stuff, without debug 
info in the libraries themselves.

Programs which you compiled (or were precompiled by others) against 
non-debug libraries would likely remain unaffected by making the debug 
version available, unless you did something special to cause those 
non-relevant programs to link against the debug version. Programs 
compiled and linked directly against those libraries would increase in 
size if the program itself had debug symbols left in (it would be odd to 
compile any other way if you really want to debug that deeply).

>>
>>Sorry for the dumb question, but I've never used debuginfo packages for
>>something so fundamental as glibc!
> 
> 
> It is my understanding that RedHat does a thing that separates the debug
> information into separate files where it doesn't conflict with the real
> executables and libraries.  gdb knows where to look up the debug
> information when it's needed and everything else ignores it.

I was hoping to hear more about it myself. I've seen the separate debug 
package info, but not certain how gdb deals with it or knows to use it. 
Maybe gdb itself was modified? Don't know.

D. Stimits, stimits AT comcast DOT net