Date:	Wed, 9 Sep 1998 17:55:19 +0200 (WET)
From:	Andris Pavenis <pavenis AT lanet DOT lv>
To:	DJ Delorie <dj AT delorie DOT com>
cc:	djgpp-workers AT delorie DOT com
Subject:	Re: Updated diffs for compiling DJLSR-980907 with EGCS-1.1
In-Reply-To:	<199809091316.JAA19165@delorie.com>
Message-ID:	<Pine.A32.3.91.980909172215.42792A-100000@ieva01.lanet.lv>
MIME-Version:	1.0

On Wed, 9 Sep 1998, DJ Delorie wrote:

> 
> OK, the real question is - why do we need to remove the const-ness?
> There's no reason why those functions need to change those parameters,
> so why can't they accept the const parameters?
> 

Unfortunatelly egcs-1.1 gives warning in cast:
    const char * foo;

    (char * const *) & foo;

when gcc option -Wcast-qual is specified. It compiles Ok with both
gcc-2.7.2.1 and gcc-2.8.1 but not with egcs-1.1. I think that compiler
is right as 'char * const *' is constant pointer to string, so
cast removes const and of course compiler should issue warning
(when -Wcast-qual is specified).

Specifying 'const char * const *' in parameters is not a solution
for global function as then we are not able to specify variable 
with type char ** as a parameter (what would ve very annoying). 
Here is an example that ilustrates this (compiled under Linux, but
I'm getting the same with DJGPP)
-----------------------------------------
hal:~/tmp# cat xx.c
int foo1 (const char * const *);
int foo2 (char * const *);
int bar (const char * xx , char * yy)
  {
      foo1 (&xx);
      foo2 (&xx);
      foo2 ((char * const *) & xx);
      foo1 (&yy);
      foo2 (&yy);
      return 0;
  }
-----------------------------------------
hal:~/tmp# gcc -c -Wcast-qual xx.c
xx.c: In function `bar':
xx.c:6: warning: passing arg 1 of `foo2' from incompatible pointer type
xx.c:7: warning: cast discards `const' from pointer target type
xx.c:8: warning: passing arg 1 of `foo1' from incompatible pointer type
hal:~/tmp#
-----------------------------------------

One more thing. Tried to build DJLSR using cross-compiler under Linux
(the same version: egcs-1.1). Some problems I met:
   - native libc.a include files (libc-5.4.46) defines POSIX_SOURCE
     that effectively eliminates contents of coff.h from djcrx202.zip;
   - I used binutils 2.9.1.0.10 (same source archive as I'm using
     under Linux). There were some changes in i86 assembler and I had
     to modify some sources in src/ansi/math. I checked that after these
     changes sources still compiles also under DOS.

Looks that crossbuilding DJLSR under Linux is much more faster than 
native one. I haven't checked results yet so let's see what I have got.

Perhaps I'll include examples of scripts for building cross to DJGPP
compiler with next update of egcs-1.1 sources.

Andris

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