CPP warnings under DJGPP

CPP warnings under DJGPP

[Laurynas Biveinis]

Current code in cppfiles.c (read_with_read()) assumes that 
read() asked to read whole file at once would return the
size of file as a number of bytes read. However, if file
is opened as text under DJGPP and newline conversion takes
place, this is not true - read() returns smaller number.
This leads to harmless but confusing warnings 
'file.h is shorter than expected' everywhere.

read() can be made to behave as code expects under DJGPP by
passing additional flag O_BINARY to it:

  return open (filename, O_RDONLY|O_NOCTTY
#ifdef DJGPP
|O_BINARY
#endif
), 0666);

However, if other DOS-based platforms have different ways to
do this or GCC maintainers want a cleanier fix, another
solution is required?

Laurynas

Re: CPP warnings under DJGPP

[Per Bothner]

Laurynas Biveinis <lauras@softhome.net> writes:

>   return open (filename, O_RDONLY|O_NOCTTY
> #ifdef DJGPP
> |O_BINARY
> #endif
> ), 0666);
> 
> However, if other DOS-based platforms have different ways to
> do this or GCC maintainers want a cleanier fix, another
> solution is required?

I've used
        #ifndef O_BINARY
        #define O_BINARY 0
        #endif
as a relatively clean solution to this DOS brain-damage.

(By brain-damage I don't mean using crlf, though in retrospect that
was a mistake.  Nor do I complain that files do crlf-conversion
by default.  The big mistate, which we now have to live with, was
having posix (open'd) files do crlf-conversion by default, since
it forces extra buffering.)
-- 
	--Per Bothner
per@bothner.com   http://www.bothner.com/~per/