Re: New Alpha - Gpc

16 Apr 1997


      According to Frank Heckenbach:
...
BTW: You recently said that one has to use '-pedantic', not '-fpedantic'
in specs. Is there a general rule when to use '-f...' and when simply '-...'?
AFAIK, the GNU compiler originally accepted only `-ffoo-bar' flags.
(The `-f' stands for "flag".)  Nowadays, just `--' is okay as an
alternative for `-f'.  (Note that these long options start with two
dashes, not just one.)  The `specs' file only understands the old
syntax.
`--pedantic' is an exception, because it is originally `-pedantic' (with
one dash), not `-fpedantic' (i.e. no "flag" in this sense).
To get all options, read the (loooooooooooong) section "Invoking GPC"
from the info documentation, and pick up the flags not explained there
from my "New Alpha" announcements.  In the worst case, look at the GPC
source file `gpc-options.h' for a list of all `--' (or `-f') options,
and see `gpc-decl.c' for what they do.
...
Just to make sure: 'AutoMake="--foo"' means that '--foo' is used for the
compilation of the units involved and the program itself, while
'AutoMake, --foo' would apply '--foo' only to the program. Is that right?
Almost.  Within the directive, `--' (in fact: `-f') is automatically
prefixed, so don't give it explicitly.
(*$AutoMake="--foo"*)        correct; gives `--foo' to the compilation
                                 of Units
    (*$AutoMake="foo"*)          wrong; gives `foo' to the compilation of
                                 Units (which is nonsense)
    (*$AutoMake,foo*)            correct; gives `--foo' to the current
                                 compilation
    (*$AutoMake,--foo*)          wrong; gives `----foo' (in fact: `-f--foo')
                                 to the current compilation.
...
A minor "problem": If I compile a program with such a compiler switch with TP,
TP complains about an "Invalid compiler directive". Is there a way [...]
to supply the options so that gpc will recognize them and TP will ignore
them?
Yes, conditional defines.  GPC pre-defines the symbol "__GPC__":
(*$ifdef __GPC__ *)
      (* GNU Pascal switches *)
      (*$no-field-widths *)
      (*$AutoMake="--foo --bar"*)
      (*$N+*)  (* Nested comments *)
      (*$E-*)  (* No C-style char escapes *)
    (*$else *)
      (* Borland Pascal switches *)
      (*$M 65536 *)  (* Stack size *)
      (*$N+*)  (* Numeric coprocessor on *)
      (*$E-*)  (* Don't link the Emulator *)
    (*$endif *)
    (* Switches for both compilers *)
    (*$B-*)  (* Short-circuit Boolean operators *)
...
(perhaps a simpler way than conditional defines)
What would you consider "simpler" than this? ;-)
...
What about compiler options for "-o foo", "foo.o" and/or "bar.c"? Are you
working on them, or are they too difficult to implement?
Working on them.  I don't expect much trouble from (*$L foo.o *) and
(*$L bar.c *), but I am not so sure about "-o foo" ...
...
BTW: Is it legal (with the currect version) to use "gpc foo.c bar.pas"?
I asked about this already in my mail about "Re: Linking directives..." on
3 Apr, but unfortunately got no replies.
Oh - sorry, I overlooked it.  #-)  Yes, it's legal, and it works on my
Linux box, too.  (You wrote that it didn't work on yours; perhaps this
bug is fixed now?)
...
And another contribution to the GPC test suite... :-|
The following program and unit cause the latest gpc to fail with SIGSEGV.
It worked with a previous version of gpc [...]
I can reproduce the error.  Okay, it will be fixed in the next Alpha.
(I hope at least.;)
Greetings,
Peter
Dipl.-Phys. Peter Gerwinski, Essen, Germany, free physicist and programmer
peter.gerwinski@uni-essen.de - http://home.pages.de/~peter.gerwinski/ [970201]
 maintainer GNU Pascal [970412] - http://home.pages.de/~gnu-pascal/ [970125]