fpc/compiler/README

This directory contains the sources of the Free Pascal Compiler

To recompile the compiler, use the batch file
mppc386.bat

If you want to build a m68k version to cross compile from i386 to m68k
use the batch file
mppc68k.bat

If you want to compile/modify the compiler, please read first the
programmers manual.


Changes in the syntax or semantic of FPC:
-----------------------------------------
  28/01/99   implicit conversion from boolean to integer is not possible
             anymore (solved several bugs) but this could lead to errors
             on previously accepted code (PM)
  01/02/99   c styled comments are supported (/* ... */), mainly
             for the Sibyl sources of Medigo (FK)
  02/02/99   class destructors take now two parameters: flag
             if the helper routine should free the instance and
             self pointer (FK)
  22/02/99   PROTECTED and PRIVATE have now the same behavior
             as in TP
  09/03/99   small records and arrays passed by value to a function are now directly copied
             into a 4 bytes parameter (needed for C and DLL calls) (PM)
  11/03/99   the makefile.fpc is now also needed for the compiler and RTL, you can
             find it in the base.zip package (PFV)
  24/03/99   new directives UNITPATH,INCLUDEPATH,OBJECTPATH,LIBRARYPATH to
             set the searchpaths where to find the files for that module (PFV)
  25/03/99   new directive STATIC +/- or on/off , works like -St commandline
             switch
  02/04/99   rtl/cfg/ directory has been removed, it's not used anymore
  15/04/99   FINALIZATION is supported
  21/04/99   Default assembler for i386 changed to AT&T instead of direct
  25/04/99   initialized vars supported in Delphi mode (only $J+ mode)
             getting the address of an untyped const is now
             forbidden as in BP
  27/04/99   New unit format PPU016, you need to recompile all older units
  01/05/99   Internal assembler. Assembler readers now support MMX,KNI
             instructions.
  12/05/99   rtl/utils/ directory moved to utils/. Moved the utils only needed
             for compiler development to compiler/utils/
  13/05/99   Classes are now only allowed in the ObjFpc or Delphi mode. Use
             {$mode objfpc} or {$mode delphi}. Or from commandline -S2 or -Sd
  16/05/99   Remove options -Up (use now -Fu) and -Fg (use now -Fl)
  17/05/99   Redesign of ansistring temporary handling, please report
             any problems
  17/05/99   Most stuff of the objpas unit is now in the system unit
             because the new temporary ansistring handling support
             exceptions and exceptions need the class OOP model
  18/05/99   The compiler will stop directly if there are errors in the
             commandline parameters
  16/08/99   DLL are relocatable by default (need to strip symbols)
             -WN make non relocatable DLL (which can retain debug info)
             for both type of DLL the prefered image base can be specified
             with -WB1100000 for instance to get image base at $11000000.
  08/09/99   pointer addition/substraction (only available in fpc,objfpc mode)
             now uses the size of the type the pointer points to, just like
             inc(),dec() already did. Now inc(p) is the same as p:=p+1.
             But old code can be broken by this when there is a p:=p+4 then
             it's now parsed like: p:=p+4*sizeof(type). To get the old situation
             you can use typecasting: p:=ptype(pointer(p)+4).
  08/09/99   class/object field return their offsets in the object/class. You
             must access them self with loading the object/class pointer and
             then create a reference where you add the field
  07/11/99   Small change to property writing in PPU => all units
             exporting classes with properties must be recompiled
             (no new unit format, so be careful) (FK)
  08/11/99   PP variable in Makefiles changed to FPC
  14/11/99   makefile.fpc is not available anymore. You must now use fpcmake
             which is available from the utils/. There is also an example
             Makefile.fpc
  15/02/00   The support of the fixed data type has been removed from the
             compiler because
                1. it is buggy
                2. it is very seldom used
                3. the single data type is faster on modern cpus (Pentium+)

             If still want to use it, you have to recompile the compiler
             with -dSUPPORT_FIXED and recompile the rtl with that compiler.
             To find out if the used compiler supports the fixed data
             type, check the directive HASFIXED  (FK)
  29/02/00   ORDERSOURCES released => PPU version change
             this allows for a more correct include file hunting order.
  01/04/00   fix the handling of value parameters in cdecl function
  11/05/00   changed vmt handling to fix problems some problems
             with overloading in objects
  11/11/00   default parameter support
  11/11/00   you can declare a pointer type with directive far; to make
             it a farpointer. Only usefull for dos.
  11/11/00   ptr() returns a farpointer instead of pointer. Becuase the
             pointer result would be useless and only causing segmentation
             faults. With the farpointer this would already be detected at
             compiletime. To get the code working you can declare a pointer
             with far; like:

             type
               farlongint = ^longint;far;
             var
               timer : farlongint;
             begin
               timer:=ptr($40,$6c);
               writeln(timer^);
             end.
  07/12/00   constant handling has been rewritten: hex constants <=$ffffffff
             are now always parsed as unsigned numbers (because of the int64
             constant support, the were always sign-extended before). This
             may force you to add longint typecasts round hex numbers in
             your programs to avoid range check errors.
  10/04/01   Argument names are now checked if names are the same in the
             both the forward (interface) and implementation declaration
  13/04/01   It's not possible anymore (except in -So mode) to pass a cardinal
             to a parameter declared with a "var longint". The same goes for
             the other signed-unsigned like smallint-word and shortint-byte.
  13/04/01   in FPC mode you're now always forced to use @ to get the address
             of a procedure and load it in a procedure variable. Before it was
             sometimes a bit more relaxed
  03/06/01   hint directives (library,platform,deprecated) are parsed, but
             futher ignored