Compiler options fail to replicate fpc -Mtp
lazarus / 11-Options

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Ed · 2005-09-26 18:00

I was migrating code from Turbo Pascal 7 for DOS to linux, and have
most of it compiling using the command line fpc source -Mtp.  I just
started using Lazarus.  I get new errors, and have now chosen ONLY the
-So option for the project compiler options.  It still gives a pointer
to a procedure error that -Mtp does not.  I see no other source code
tricks I can use to sidestep the compiler error, so feel that I need
to keep the pointer comparison such as:

IntHandler: pointer;

If (IntHandler <> @SomeIntHandler) then...

I tried the $T+ and $T-, but nothing changes.  I get "expected longint
but got ^procedure(Word,word...)

I see no way to force any other options, or specifically -Mtp.

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Vincent Snijders · 2005-09-27 06:12

Please, give a more complete code sample, including variable and type
declarations.

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Anonymous · 2005-09-27 17:46

Quote from: "Vincent"Please, give a more complete code sample,
including variable and type declarations.

I will do that, but the code is at home.  Tthe main part of the
question is why does the command line execution of fpc compile but the
same code from Lazarus does not?  Lazarus runs the same compiler, does
it not?

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Anonymous · 2005-09-27 18:02

Yes, but the options passed might be different.

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Vincent Snijders · 2005-09-27 18:10

Somehow, the forum forgot who I am.

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Anonymous · 2005-09-28 00:14

The code is

Procedure SetInterrupts(IntHandler: Pointer; InterruptFrequency:
Single);
Begin
   Asm
      CLI;   //Inline($FA);                         {CLI - disable
interrupts during vector change}
   end;
   If (IntHandler <> @RUSHandler) then

I keep getting Error: Incompatible types: got "<address of
procedure(Word, Word, Word, Word, Word, Word...); Register>" exptected
"LongInt"

Thanks.

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Vincent Snijders · 2005-09-28 06:21

I still can't even try to compile this code. Can you give a complete
example  including variable and type declarations?

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Marc · 2005-09-28 14:27

I can reproduce it with the following app: Code: [Select]
program a;


procedure RUSHandler(a,b,c,d,e,f: Word);
begin
end;

Procedure SetInterrupts(IntHandler: Pointer; InterruptFrequency:
Single);
Begin
  Asm
    CLI; //Inline($FA); {CLI - disable interrupts during vector
change}
  end;
  If (IntHandler <> @RUSHandler) then
end;

begin
end.


When you compile like this, without specifying mode, fpc compiles in
its native fpc mode. This mode is similar to tp.
Somehow the result of @ is typed on comparisations.

As a workaround you can typecast: -> Pointer(@RUSHandler)

For a better explanation, you can thry the fpc forum or the fpc
mailinglist, since this is not realy a lazarus issue (and I'm not that
deep into the fpc internals of different modi)

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Ed · 2005-09-29 03:20

Thanks.  My point was that the snippet of code I gave (more complete
code is like that proposed by Marc) compiles just fine with the
command line

fpc -Mtp source.pas

but does not with Lazarus when I specify the -So compile option, which
is supposed to be equivalent to -Mtp.  I wanted to know how to
perfectly replicate fpc -Mtp to successfully compile my source from
within Lazarus.

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Vincent Snijders · 2005-09-29 05:39

Thanks, Marc, for the complete example. Now, at least, I can reproduce
the problem and see for myself that your example code only needs the
-So parameter (and that it is equivalent to -Mtp). No need to change
the code.

I cannot reproce the problems Ed is having, because I cannot compile
his snippet
Code: [Select]project1.pas(9,20) Error: Identifier not found
"RUSHandler"

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Ed · 2005-09-30 02:42

Here is a distilled program:

Program TestHandler;

Procedure RUSHandler(Flags,CS,IP,AX,BX,CX,DX,SI,DI,DS,ES,BP: Word);
Begin
end; {RUSHandler}

Procedure SetInterrupts(IntHandler: Pointer; InterruptFrequency:
Single);
Begin
  If (IntHandler <> @RUSHandler) then
    {do something}
end;

Begin {Main program}
  SetInterrupts(@RUSHandler, 5000.0)
end.

I verified that Lazarus was using no optons but -So, and it still had
a compiler error that I do not get when I invoke the compiler from the
command line with -Mtp.  I do see that the forced typecasting as
suggested by Marc "Pointer((@RUSHandler)" did work, so this becomes
less important.  I still wonder why the results differ...

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Vincent Snijders · 2005-10-03 06:34

All I can say is, that this sample app compiles here using fpc 2.0.0
and 2.0.1.