{$IFC vs {$IF syntax

Elements Oxygene
1

I’m porting some older Mac and Free Pascal code. They use
{$IFC XXXX} {$ELSEC} {$ENDC} syntax. Is there a way to get Oxygene to recognize this syntax?

2

While I’m at it, is there any way to get .p file extensions treated as .pas for Oxygene?

3

I’ve never seen this syntax before, you have any help references for it?

4

I’m moving free pascal code. Link:
http://www.freepascal.org/docs-html/prog/progsu30.html
which says: "In MACPAS mode, this directive can be used as an alternative to the $IF directive. It is supported for compatibility with existing Mac OS pascal compilers. "
and some of this code is common across several platforms, including Mac OSX, Classic, iOS and even Windows.

5

pmfji - I was curious as well, and found this:

http://www.freepascal.org/docs-html/prog/prog.html

In essence the $xxxC directives seem to be 1:1 equivalent to the corresponding $xxx directive, e.g.

$DEFINEC => $DEFINE

The only variations to this rule seem to be where the $xxxC variant employs a slightly different xxx component in the symbol:

$ELIFC => $ELSEIF
$ENDC  => $ENDIF
6

Do they use the same DEFINE scope to a different one? Do the C versions mix with the non-C ones,nor are they processed independently?

7

They use the C versions across all platforms. For now, I’ve gotten permission to convert them for my use to the non-C flavors. Though it will have to be dealt with later when we merge the common code. The $ifdef / $ifndef syntax is different in the common code as well. If you manage to add it, great.

Also, just to reiterate the follow-up question I had, is there a way to have it natively recognize .p file extensions as the equivalent of .pas?

8

what i meant was;

(a)

{$DEFINE A}
{$IFDEFC A}
// does it see A?

(b)

{$IFDEFC A}
{$IFDEF B}
{$ENDIFC} // will this match $IFDEF B or $IFDEFC A?
{$ENDIF}
9

I don’t have all the tools for all the platforms, but Laz/FPC on (a) sees A. And for (b) this test:

{$DEFINE A}
// {$DEFINE B}

{$IFDEFC A}
{$IFDEF B}
test = a;
{$ENDIFC} // will this match $IFDEF B or $IFDEFC A?
{$ENDIF}

compiles without error. If the {$DEFINE B} is uncommented, it complains about the non-pascal syntax there. So at least Laz/FPC seems agnostic as to whether the C is there or not.

What the Mac Pascal compilers would do, I don’t know.

Is that closer to answering the question you were asking?

10

I am speculating a little here, but what I interpret from the Lazarus documentation is that the C variant directives are provided for compatibility with Mac Pascal. e.g. / i.e. Mac Pascal uses $IFDEFC and doesn’t support $IFDEF at all. In FPC the ‘C’ versions are simply treated as equivalent to their non-C counterparts and hence can be mixed-in and must then follow the same rules that would apply if either the C or non-C versions had been used exclusively.

I’ve been trying to find any Mac Pascal references that would clear up the question of whether those compilers supported both C and non-C variants and, if they did, what rules applied. But everything in this area currently seems to come from FPC.

So I wonder, do you have to continue to support Mac Pascal in anything other than FPC ?

If not, then the behaviour of a Mac Pascal compiler is moot. FPC is your baseline.

And if FPC treats the C/non-C versions as directly equivalent, and you do not need to maintain compatability with Mac Pascal, then there is no issue caused by simply replacing the C variants with the non-C counterparts, and you can have consistent code in both your FPC and Oxygene environments. Win-Win. :slight_smile:

But there’s a lot of "if"s in there. :slight_smile:

11

There are folks using the Mac Pascal compilers on the code. But we’ve decided to just work around it.

Now if I could just get Oxygene to recognize .p file extensions as easily as .pas…