Message-Id:	<199801201238.OAA00105@ankara.duzen.com.tr>
Comments:	Authenticated sender is <mitch AT ankara DOT duzen DOT com DOT tr>
From:	"S. M. Halloran" <mitch AT duzen DOT com DOT tr>
Organization:	User RFC 822- and 1123-Compliant
To:	djgpp AT delorie DOT com
Date:	Tue, 20 Jan 1998 14:39:26 +0200
MIME-Version:	1.0
Subject:	Re: Strip.exe
In-reply-to:	<34C413B2.CF1@geocities.com>

On 19 Jan 98, Scarius was found to have commented thusly:

> Jochen Erwied wrote:
> 
> > It removes the linked-in symbols of your program. Same effect as if you link
> > your program with 'gcc -s -o <program> ...'
> 
> I'm just dumb, but what does that mean? As I understand compiling
> (been working on some simple compilers of my own), there wouldn't be
> any symbols left in the finished, compiled program. Maybe I just
> don't understand. Thx

There would be symbols--variable names, identifiers-left in
(appended to) object code if you wanted to do source-level debugging. 
 The Unix utility sdb (Symbolic DeBugger) is a prime example.  It 
requires that object code be compiled with symbol references in order 
to debug code at the source level.  Its GNU equivalent is gdb.  The 
Borland IDE equivalent in the DJGPP distribution is RHide.

The C compiler (cc, gcc, tcc <--Borland's) needs to be told to 
include symbolic information for debugging operations in which you 
want to include your source.  Generally you flag the compiler by 
passing it the option '-g' to tell it to include the symbols.  The 
default is generally NOT to include symbols for source-level 
debugging in the object code.

If you use the C compiler/linker only to link your objects to form an 
executable in which the objects have already been compiled 
and include the extra debugging information, then you would use the 
command line given above for 'gcc' simultaneously to 'strip' away the 
debugging info and to link it.  The '-s' option is on the command 
line as the programmer may be assuming--or wants to make sure--that 
no debugging information is included.

Now the question for developers of gcc is, what is the object file 
format of code that includes symbol references?  How are external 
references (global variables, functions), static variables (both in 
file and block scope), and automatic variables (locals) organized for 
use by the debugger?

Mitch Halloran
Research (Bio)chemist
Duzen Laboratories Group
Ankara   TURKEY
mitch AT duzen DOT com DOT tr

other job title:  Sequoia's (dob 12-20-95) daddy

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