Date: Tue, 25 Aug 1998 14:36:50 +0300 (IDT) From: Eli Zaretskii To: andrewc AT rosemail DOT rose DOT hp DOT com cc: djgpp-workers AT delorie DOT com, robert DOT hoehne AT gmx DOT net Subject: Re: GCC incompatibilities In-Reply-To: <199808241743.AA247760603@typhoon.rose.hp.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Precedence: bulk On Mon, 24 Aug 1998, Andrew Crabtree wrote: > > compatibility problems between object files produced by > > different versions of GCC. > In many cases, yes. Most seem to be related to c++ stuff. Are there *any* problems whatsoever related to C? For example, is the stock libc.a good for GCC 2.8.1/EGCS/PGCC? > The biggest gotchas here have been exception handling and rtti I > think. Is Robert's recommendation to use -fno-exceptions -fno-rtti at all relevant to C programs which mix objects compiled by different versions of GCC? > These are usually easy to find because you will get unresolved externals > when linking. Unfortunately, many DJGPP users get utterly confused when they see unresolved externals. A large part of the FAQ is devoted to sorting these problems out, and they still get confused. > No. This is another (maybe another 2 issues). The crt code for > djgpp 2.01 doesn't align the stack. Its not an incompatibility, but > it can slow things down a lot. I recommend that people recompile > all of their libs with pgcc just to get the small speed increase. It > is not actually required ..... unless you want to use any of the -m > options that break the abi Do I understand correctly that the stack alignment issue (corrected in v2.02, btw) only affects speed *iff* one of those -mXXX switches are used, but otherwise has no effect?