Home

Users` Guide

1. data i value writeln lt UL gt end While this program isn t shorter than the C program provided as an example at NCSA it doesn t need any other units everythig is done using standard Pascal procedures Note that this program has a limitation the length of names and values is limited to 255 characters This is due to the fact that strings in Pascal have a maximal length of 255 It is of course easy to redefine the datarec record in such a way that longer values are allowed In case you have to read the contents of a TEXTAREA form element this may be needed Data passed through an environment variable If your form uses the GET method of passing it s data the CGI script needs to read the QUERY_STRING environment variable to get it s data Since this variable can and probably will be more than 255 characters long you will not be able to use normal string methods present in pascal Free Pascal implements the pchar type which is a pointer to a null terminated array of characters And fortunately Free Pascal has a unit which eases the use of the pchar type The following example illustrates what to do in case of a method of GET program cgi_get 2actually this program will give faulty results since spaces in the input are converted to plus signs by the web browser The program doesn t check for this but that is easy to change The main concern here is to give the working principle 48 9 1
2. al Tells the compiler to include the sourcecode lines in the assembler file as com ments This feature is still experimental and should be used with caution ar tells the compiler to list register allocation and release info in the assembler file This is primarily intended for debugging the code generated bythe compiler at tells the compiler to list information about temporary allocations and deallo cations in the assembler file Axxx specifies what kind of assembler should be generated Here xxx is one of the following e o A unix coff object file using the GNU assembler as e nasmcoff a coff file using the nasm assembler e nasmelf a ELF32 file LINUX only using the nasm assembler e nasmonj a obj file using the nasm assembler e masm An obj file using the Microsoft masm assembler e tasm An obj file using the Borland tasm assembler B tells the compiler to re compile all used units even if the unit sources didn t change since the last compilation b tells the compiler to generate browser info This information can be used by an Integrated Development Environment IDE to provide information on classes objects procedures types and variables in a unit bl is the same as b but also generates information about local variables types and procedures 21 5 1 USING THE COMMAND LINE OPTIONS CD Create a dynamic library This is used to transform units into dynamically linkable libraries on LINUX
3. COPY B G032 EXE PROG PROG EXE assuming Free Pascal created a file called PROG of course This becomes then a stand alone executable for DOS which doesn t need the GO32 EXE on the machine where it should run PMODE D4J You can also use the PMODE DJ extender to run your Free Pascal applications To make an executable which works with the PMODE extender you can simply create an GO32V2 executable the default and then convert it to a PMODE executable with the following two extra commands 1 First strip the GO32V2 header of the executable 16 3 7 REDUCING THE SIZE OF YOUR PROGRAM EXE2COFF PROG EXE we suppose that PROG EXE is the program generated by the compilation process 2 Secondly add the PMODE stub COPY B PMODSTUB EXE PROG PROG EXE If the PMODSTUB EXE file isn t in your local directory you need to supply the whole path to it That s it No additional steps are needed to create a PMODE extender executable Be aware though that the PMODE extender doesn t support virtual memory so if you re short on memory you may run unto trouble Also officially there is not support for the PMODE DJ extender It just happens that the compiler and some of the programs it generates run under this extender too 3 7 Reducing the size of your program When you created your program it is possible to reduce its size This is possible because the compiler leaves a lot of information in the program which str
4. UNDEF Syntax UNDEF name UNDEF un defines a keyword if it existed This has the same effect as a uname command line option 26 5 2 USING THE CONFIGURATION FILE WRITE Syntax WRITE Message Text WRITE writes Message Text to the screen This can be useful to display warnings if certain options are set Example IFDEF DEBUG WRITE Setting debugging ON 8 ENDIF if DEBUG is defined this will produce a line Setting debugging ON and will then switch on debugging information in the compiler INCLUDE Syntax INCLUDE filename INCLUDE instructs the compiler to read the contents of filename before continuing to process options in the current file This can be useful if you want to have a particular configuration file for a project or under LINUX in your home directory but still want to have the global options that are set in a global configuration file Example IFDEF LINUX INCLUDE etc ppc386 cfg ELSE IFDEF GO32V2 INCLUDE c pp bin ppc386 cfg ENDIF ENDIF This will include etc ppc386 cfg if you re on a linux machine and will include c pp bin ppc386 cfg on a dos machine SECTION Syntax SECTION name The SECTION directive acts as a IFDEF directive only it doesn t require an ENDIF directive the special name COMMON always exists i e lines following SECTION COMMON are always read 27 5 3 VARIABLE SUBSTITUTION IN PATHS 5 3 Variable substituti
5. Fatal Unknown float type The compiler cannot determine the kind of float that occurs in an expression Fatal SecondVecn base defined twice An internal error occurred in the com piler If you encounter such an error please contact the developers and try to provide an exact description of the circumstances in which the error occurs Fatal Extended cg68k not supported The varextended type is not supported on the m68k platform Fatal 32 bit unsigned not supported in MC68000 mode The cardinal is not supported on the m68k platform 79 C 7 UNIT LOADING MESSAGES Fatal Internal Error in secondinline An internal error occurred in the com piler If you encounter such an error please contact the developers and try to provide an exact description of the circumstances in which the error occurs Register argl weight arg2 arg3 Debugging message Shown when the compiler considers a variable for keeping in the registers Error Stack limit excedeed in local routine Your code requires a too big stack Some operating systems pose limits on the stack size You should use less vari ables or try ro put large variables on the heap Stack frame is omitted Some procedure functions do not need a complete stack frame so it is omitted This message will be displayed when the vd switch is used Error Object or class methods can t be inline You cannot have inlined ob ject methods Error Procvar calls can t be inline A procedure
6. PPU Time arg1 When you use the vu flag the unit time is shown 76 C 7 UNIT LOADING MESSAGES PPU File too short When you use the vu flag the unit time is shown PPU Invalid Header no PPU at the begin A unit file contains as the first three bytes the ascii codes of PPU PPU Invalid Version arg1 This unit file was compiled with a different version of the compiler and cannot be read PPU is compiled for an other processor This unit file was compiled for a dif ferent processor type and cannot be read PPU is compiled for an other target This unit file was compiled for a differ ent processor type and cannot be read PPU Source argl When you use the vu flag the unit CRC check is shown Writing arg1 When you specify the vu switch the compiler will tell you where it writes the unit file Fatal Can t Write PPU File An err Fatal reading PPU File Unexpected end of file Fatal unexpected end of PPU File This means that the unit file was cor rupted and contains invalid information Recompilation will be necessary Fatal Invalid PPU File entry arg1 The unit the compiler is trying to read is corrupted or generated with a newer version of the compiler Fatal PPU Dbx count problem There is an inconsistency in the debugging information of the unit Error Illegal unit name argl The name of the unit doesn t match the file name Fatal Too much units Free Pascal has a limit of 1024 units in a program You c
7. e You reference a type which isn t declared in the current type block Fatal Identifier type already defined as type You are trying to redefine a type Error Error in type definition There is an error in your definition of a new array type One of the range delimiters in an array declaration is erroneous For example Array 1 1 25 will trigger this error Error Type identifier not defined The type identifier has not been defined yet Error Forward type not resolved arg1 The compiler encountered an unknown type 72 C 5 SYMBOL HANDLING Error Only static variables can be used in static methods or outside methods A static method of an object can only access static variables Error Invalid call to tvarsym mangledname An internal error occurred in the compiler If you encounter such an error please contact the developers and try to provide an exact description of the circumstances in which the error occurs Fatal record or class type expected The variable or expression isn t of the type record or class Error Instances of classes or objects with an abstract method are not allowed You are trying to generate an instance of a class which has an abstract method that wasn t overridden Warning Label not defined arg1 A label was declared but not defined Error Illegal label declaration Error GOTO and LABEL are not supported use switch Sg You must compile a program which has labels and goto statements w
8. re indexing a variable that is not an array e You re dereferencing a variable that is not a pointer Error High range limit low range limit You are declaring a subrange and the lower limit is higher than the high limit of the range Error Illegal counter variable The type of a for loop variable must be an ordinal type Loop variables cannot be reals or strings Error Can t determine which overloaded function to call You re calling over loaded functions with a parameter that doesn t correspond to any of the de clared function parameter lists e g when you have declared a function with parameters word and longint and then you call it with a parameter which is of type integer Error Parameter list size exceeds 65535 bytes The 386 processor limits the parameter list to 65535 bytes the RET instruction causes this Error Illegal type conversion When doing a type cast you must take care that the sizes of the variable and the destination type are the same Conversion between ordinals and pointers is not portable across platforms If you typecast a pointer to a longint this code will not compile on a machine using 64bit for pointer storage 74 C 6 CODE GENERATOR MESSAGES Error File types must be var parameters You cannot specify files as value parameters i e they must always be declared var parameters Error The use of a far pointer isn t allowed there Free Pascal doesn t sup port far pointers so you ca
9. shows this h h shows this h coff file using Nasm elf32 Linux file using Nasm obj file using Nasm obj file using Masm Microsoft obj file using Tasm Borland ading style read AT amp T style assembler read Intel style assembler copy assembler text directly to assembler file s generate smaller code generate faster code default keep certain variables in registers still BUGGY enable uncertain optimizations see docs level 1 optimizations quick optimizations level 2 optimizations 01 slower optimizations level 3 optimizations same as 02u target processor 0p1 set target processor to 386 486 0p2 set target processor to Pentium PentiumMMX tm 0p3 set target processor to PPro PII c6x86 K6 tm ting system version 1 of DJ Delorie DOS extender version 2 of DJ Delorie DOS extender Linux 0S 2 2 x Windows 32 Bit elp elp without waiting 54 Appendix B Alphabetical lst of reserved words absolute abstract and array as asm assembler begin break case cdecl class const constructor continue destructor dispose div do downto else end except exit export exports external fail false far file finally for forward function goto if implementation in index inherited initialization inline interface interrupt is label library mod name near new nil not object of on operator or otherwise 55 packed popstack private procedure pr
10. GETTING YOUR DATA uses strings linux const max_data 1000 type datarec record name value string end var data array 1 max_data of datarec i nrdata longint p PChar literal aname boolean begin Writeln Content type text html Writeln if StrComp GetEnv REQUEST_METHOD POST lt gt 0O then begin Writeln This script should be referenced with a METHOD of GET write If you don t understand this see this write lt A HREF http www ncsa uiuc edu SDG Softare Mosaic Writeln Docs fill out forms overview html gt forms overview lt A gt halt 1 end p GetEnv QUERY_STRING nrdata 1 aname true while p lt gt 0 do begin literal false if p then begin literal true inc longint p end if p lt gt and p lt gt amp or literal then with data nrdata do if aname then name name p else value value p else begin if p amp then begin inc nrdata aname true end else aname false end inc longint p end Writeln lt H1 gt Form Results lt H1 gt Writeln You submitted the following name value pairs Writeln lt UL gt for i 1 to nrdata do writeln lt LI gt data i name data i value 49 9 2 PRODUCING OUTPUT Writeln lt UL gt end Although it may not be written in the most e
11. Under LINUX you need to have the following programs installed 1 GNU as the GNU assembler 2 GNU ld the GNU linker 3 Optionally but highly recommended GNU make For easy recompiling of the compiler and Run Time Library this is needed Other than that Free Pascal should run on almost any 1386 LINUX system 2 2 Installing the compiler The installation of Free Pascal is easy but is platform dependent We discuss the process for each platform separately 2 2 INSTALLING THE COMPILER Installing under DOS Mandatory installation steps First you must get the latest distribution files of Free Pascal They come as zip files which you must unzip first or you can download the compiler as a series of separate files This is especially useful if you have a slow connection but it is also nice if you want to install only some pats of the compiler distribution The distribution zip file contains an installation program INSTALL EXE You must run this program to install the compiler The screen of the installation program looks like figure BU The program allows you to select e What components you wish to install e g do you want the sources or not do you want docs or not Items that you didn t download when downloading as separate files will not be enabled i e you can t select them e Where you want to install the default location is C PP In order to run Free Pascal from any directory on your system you must
12. it looks for ppc386 cfg 3 The directory specified in the environment variable PPC_CONFIG_PATH and if it s not set under etc e Under all other OSes 1 The current directory 2 Ifit is set the directory specified in the environment variable PPC_CONFIG_PATH 3 The directory where the compiler is 14 3 4 COMPILING A PROGRAM 3 4 Compiling a program Compiling a program is very simple Assuming that you have a program source in the file prog pp you can compile this with the following command ppc386 options prog pp The square brackets indicate that what is between them is optional If your program file has the pp or pas extension you can omit this on the command line e g in the previous example you could have typed ppc386 options prog If all went well the compiler will produce an executable or for version 1 of the DOS extender a file which can be converted to an executable Unless you are using DOS and version 1 of the DOS extender the file you obtained is the executable You can execute it straight away you don t need to do anything else Under version 1 of the DOS extender additional processing is required See section on how to create an executable in this case You will notice that there is also another file in your directory with extensions o This contains the object file for your program If you compiled a program you can delete the object file Lol but not if you compiled a u
13. Chxxx Reserves xxx bytes heap xxx should be between 1024 and 67107840 Ci Generate Input Output checking code In case some input output code of your program returns an error status the program will exit with a run time error Which error is generated depends on the I O error Cn Omit the linking stage Co Generate Integer overflow checking code In case of integer errors a run time error will be generated by your program Cr Generate Range checking code In case your program acesses an array element with an invalid index or if it increases an enumerated type beyond it s scope a run time error will be generated Csxxx Set stack size to xxx CS Create static library Ct generate stack checking code In case your program performs a faulty stack operation a run rime error will be generated Cx Use smartlinking when compiling and linking units smartlinking will only link in the code parts that are actually needed by the program All unused code is left out This can lead to substantially smaller binaries dxxx Define the symbol name xxx This can be used to conditionally compile parts of your code E Same as Cn g Generate debugging information for debugging with gdb gg idem as g gd generate debugging info for dbx gh use the heaptre unit see Unit reference Oxxx optimize the compiler s output xxx can have one of the following values g optimize for size try to generate smaller code G optimize fo
14. FPC 8 3 Caveats when debugging with gdb There are some peculiarities of Free Pascal which you should be aware of when using gdb We list the main ones here l Free Pascal generates information for GDB in uppercare letters This is a consequence of the fact that pascal is a case insensitive language So when referring to a variable or function you need to make it s name all uppercase As an example of you want to watch the value of a loop variable count you should type watch COUNT Or if you want stop when a certain function e g MyFunction is called type break MYFUNCTION Line numbers may be off by a little This is a bug in Free Pascal and will be fixed as soon as possible gdb does not know sets gdb doesn t know strings Strings are represented in gdb as records with a length field and an array of char contaning the string You can also use the following user function to print strings define pst set pos amp arg0 set strlen byte pos print char amp arg0 st strlen 1 end document pst Print out a Pascal string end If you insert it in your gdb ini file you can look at a string with this function There is a sample gdb ini in appendix F Objects are difficult to handle mainly because gdb is oriented towards C and C The workaround implemented in Free Pascal is that object methods are represented as functions with an extra parameter this all lowercase The name of this function is a co
15. MOVZX 16 bit base in 32 bit segment 16 bit index in 32 bit segment 16 bit addressing is not supported you must use 32 bit addressing Constant reference not allowed It is not allowed to try to address a constant memory address in protected mode Segment overrides not supported Intel style eg rep ds stosb segment over rides are not support by the assembler parser 82 C 9 ASSEMBLER READER ERRORS Expressions of the form sreg reg are currently not supported To access a memory operand in a different segment you should use the sreg reg snytax instead of sreg reg Size suffix and destination register do not match In intel AT amp T syntax you are using a register size which does not concord with the operand size specified Invalid assembler syntax No ref with brackets Trying to use a negative index register Local symbols not allowed as references Invalid operand in bracket expression Invalid symbol name Invalid Reference syntax Invalid string as opcode operand Null label references are not allowed Using a defined name as a local label Invalid constant symbol Invalid constant expression at beginning of line not allowed NOR not supported Invalid floating point register name Invalid floating point constant Asm syntax error Should start with bracket Asm syntax error register Asm syntax error in opcode operand Invalid String expression Constant expression out of bounds Invalid or mis
16. Sg Support the label and goto commands By default these are not supported You must also specify this option if you use labels in assembler statements if you use the AT amp T style assember Sh Use ansistrings by default for strings If this keyword is specified the compiler will interpret the string keyword as a ansistring Otherwise it is supposed to be a short strings TP style Si Support C style INLINE Sm Support C style macros So Try to be Borland TP 7 0 compatible no function overloading etc Sp Try to be gpc GNU pascal compiler compatible Ss The name of constructors must be init and the name of destructors should be done St Allow the static keyword in objects Un Do not check the unit name Normally the unit name is the same as the filename This option allows both to be different Us Compile a system unit This option causes the compiler to define only some very basic types 5 2 Using the configuration file Using the configuration file ppc386 cfg is an alternative to command line options When a configuration file is found it is read and the lines in it are treated like you typed them on the command line They are treated before the options that you type on the command line You can specify comments in the configuration file with the sign Everything from the on will be ignored The compiler looks for the ppc386 cfg file in the following places e Under LINUX 1 The current directo
17. This error can easily occur if you have recursive functions 203 Heap overflow error The heap has grown beyond its boundaries ad you are rying to get more memory Please note that Free Pascal provides a growing heap i e the heap will try to allocate more memory if needed However if the heap has reached the maximum size allowed by the operating system or hardware then you will get this error 204 Invalid pointer operation This you will get if you call dispose or Freemem with an invalid pointer notably Nil 205 Floating point overflow You are trying to use or produce too large real numbers 206 Floating point underflow You are trying to use or produce too small real numbers 86 207 Invalid floating point operation Can occur if you try to calculate the square root or logarithm of a negative number 210 Object not initialized When compiled with range checking on a program will report this error if you call a virtal method without having initialized the VMT 211 Call to abstract method Your program tried to execute an abstract virtual method Abstract methods should be overridden and the overriding method should be called 212 Stream registration error This occurs when an invalid type is registered in the objects unit 213 Collection index out of range You are trying to access a collection item with an invalid index objects unit 214 Collection overflow error The collection has reached its maximal size and you are t
18. begin end 31 6 3 TURBO PASCAL COMPATIBILITY MODE The See switch disables overloading When you use it the above will compile as in Turbo Pascal 7 Operator overloading Free Pascal allows to overload operators i e you can define e g the operator for matrices 8 On FAT16 and FAT32 systems long file names are supported 6 3 Turbo Pascal compatibility mode When you compile a program with the So switch the compiler will attempt to mimic the Turbo Pascal compiler in the following ways e Assigning a procedural variable doesn t require a operator One of the differences between Turbo Pascal and Free Pascal is that the latter requires you to specify an address operator when assigning a value to a procedural variable In Turbo Pascal compatibility mode this is not required e Procedure overloading is disabled This means that function header and im plementation can be different i e the function iplementation doesn t need to repeat the function header e Forward defined procedures don t need the full parameter list when they are defined Due to the procedure overloading feature of Free Pascal you must always specify the parameter list of a function when you define it even when it was declared earlier with Forward In Turbo Pascal compatibility mode there is no function overloading hence you can omit the parameter list Procedure a L Longint Forward Procedure a No need to repe
19. compiler warns if a switch is global 57 C 2 SCANNER MESSAGES Error Illegal char constant This happens when you specify a character with its ASCII code as in 96 but the number is either illegal or out of range The range is 1 255 Fatal Cant open file arg1 Free Pascal cannot find the program or unit source file you specified on the command line Fatal Can t open include file arg1 Free Pascal cannot find the source file you specified in a include statement Error Too many argENDIFs or argELSEs Your IFDEF and ENDIF statements aren t balanced Warning Records fields can be aligned to 1 2 4 or 16 bytes only You are specifying the PACKRECORDS n with an illegal value for n Only 1 2 4 or 16 are valid in this case Warning Enumerated can be saved in 1 2 or 4 bytes only You are speci fying the PACKENUM n with an illegal value for n Only 1 2 or 4 are valid in this case Error argl expected for arg2 defined in line arg3 Your conditional compi lation statements are unbalanced Error Syntax error while parsing a conditional compiling expression There is an error in the expression following the if compiler directive Error Evaluating a conditional compiling expression There is an error in the expression following the if compiler directive Warning Macro contents is cut after char 255 to evalute expression The contents of macros canno be longer than 255 characters This is a safety
20. correctly Remember that the compiler looks for units only in the current directory and in the directory where the compiler itself is If you want it to look somewhere else too you must explicitly tell it to do so using the Up option See Or you must set op a configuration file 4 2 Problems you may encounter under DOS e No space in environment An error message like this can occur if you call SET_PP BAT in the AU TOEXEC BAT To solve this problem you must extend your environment memory To do this search a line in the CONFIG SYS like SHELL C DOS COMMAND COM and change it to the following SHELL C DOS COMMAND COM E 1024 You may just need to specify a higher value if this parameter is already set e Coprocessor missing If the compiler writes a message that there is no coprocessor install the co processor emulation e Not enough DPMI memory If you want to use the compiler with DPMI you must have at least 7 8 MB free DPMI memory but 16 Mb is a more realistic amount 18 Chapter 5 Compiler configuration The output of the compiler can be controlled in many ways This can be done essentially in two distinct ways e Using command line options e Using the configuration file ppc386 cfg The compiler first reads the configuration file Only then the command line options are checked This creates the possibility to set some basic options in the configura tion file and at the same time you can still set s
21. extend your path variable to contain the C PP BIN directory Usually this is done in the AUTOEXEC BAT file It should look something like this SET PATH PATH C PP BIN Again assuming that you installed in the default location If you want to use the graphic drivers you must modify the environment variable G032 Instructions for doing this can be found in the documentation of the Graph unit at the InitGraph procedure Optional Installation The coprocessor emulation For people who have an older CPU type without math coprocessor i387 it is necessary to install a coprocessor emulation since Free Pascal uses the coprocessor to do all floating point operations The installation of the coprocessor emulation is handled by the installation program INSTALL EXE However Installing under Linux Mandatory installation steps The LINUX distribution of Free Pascal comes in three forms e a tar gz version also available as seperate files e a rpm Red Hat Package Manager version and e a deb debian version All of these packages contain a ELF version of the compiler binaries and units the older aout binaries are no longer distributed although you still can use the comiler on an aout system if you recompile it If you use the rpm format installation is limited to 2 2 INSTALLING THE COMPILER Figure 2 1 The Dos install program screen 2 2 INSTALLING THE COMPILER rpm i fpc pascal XXX rpm XX
22. filename directive the compiler will look for it in the following places 1 It will look in the path specified in the incude file name 2 It will look in the directory where the current source file is 13 3 3 OBJECT FILES 3 it will look in all directories specified in the include file search path You can add files to the include file search path with the I See option As an example consider the following include statement in a file units foo pp i bar inc Then the following command ppc386 lincfiles units foo pp will cause the compiler to look in the following directories for bar inc 1 the parent directory of the current directory 2 the units subdirectory of the current directory 3 the incfiles directory of the current directory 3 3 Object files When you link to object files using the L file o directive the compiler will look for this file in the same way as it looks for include files 1 It will look in the path specified in the object file name 2 It will look in the directory where the current source file is 3 it will look in all directories specified in the object file search path You can add files to the object file search path with the Fo See BI option Configuration file Unless you specify the n See T option the compiler will look for a configuration file ppc386 cfg in the following places e Under LINUX 1 The current directory 2 In your home directory
23. is described in the Reference guide 1 3 Getting more information If the documentation doesn t give an answer to your questions you can obtain more information on the Internet on the following addresses e http tfdecl fys kuleuven ac be michael fpc fpc html is the main site It contains also useful mail addresses and links to other places It also contains the instructions for inscribing to the mailing list e http www brain uni freiburg de klaus fpc fpc html is a mirror of the main Free Pascal information site Both places can be used to download the Free Pascal distribution although you can probably find them on other places also Finally if you think something should be added to this manual entirely possible please do not hesitate and contact me at Let s get on with something useful Chapter 2 Installing the compiler 2 1 Before Installation Requirements System requirements The compiler needs at least the following hardware 1 An 1386 or higher processor A coprocessor is not required although it will slow down your program s performance if you do floating point calculations 2 2 Mb of free memory Under Dos if you use DPMI memory management such as under Windows you will need at least 16 Mb 3 At least 500 Kb free disk space Software requirements Under DOS The Dos distribution contains all the files you need to run the compiler and compile pascal programs Under Linux
24. known The basic building block of the configuration file consists out of one or two lines describing how ptop should react on a certain keyword First a line without square brackets with the following format keyword option1 option2 option3 If one of the options is dindonkey see further below a second line with square brackets is needed like this key word otherkeyword1 otherkeyword2 otherkeyword3 As you can see the block contains two types of identifiers keywords keyword and otherkeyword1 3 in above example and options option1 3 above Keywords are the built in valid Pascal structure identifiers like BEGIN END CASE IF THEN ELSE IMPLEMENTATION The default configuration file lists most of these Besides the real Pascal keywords some other codewords are used for operators and comment expressions table 7 The Options codewords define actions to be taken when the keyword before the equal sign is found table 7 2 The option dindonkey requires some extra parameters which are set by a second line for that option the one with the square brackets which is therefore is only needed if the options contain dinkdonkey contraction of de indent on assiociated keyword dinkdonkey deindents if any of the keywords specified by the extra options of the square bracket line is found Example The lines 37 7 1 SUPPLIED PROGRAMS Option Table 7 2 Possible options does
25. may be outdated In case of doubt consult the README files distributed with the compiler The README files are in case of conflict with this manual authoritative 1 2 About the compiler Free Pascal is a 32 bit compiler for the i386 and m68k processorg Currently it supports 6 operating systems e DOS e LINUX e ATARI version 0 99 5 only e AMIGA version 0 99 5 only e WINDows NT e os 2 using the EMX package so it also works on DOS Windows and work is in progress to port it to other platforms notably FREEBSD Free Pascal is designed to be as much as possible source compatible with Turbo Pascal 7 0 and Delphi 4 although this goal is not yet attained but it also en hances these languages with elements like function overloading And unlike these ancestors it supports multiple platforms lWork is being done on a port to ALPHA Architecture 1 3 GETTING MORE INFORMATION It also differs from them in the sense that you cannot use compiled units from one system for the other Also at the time of writing there is no Integrated Development Environment IDE available for Free Pascal This gap will hopefully be filled in the future Free Pascal consists of three parts 1 The compiler program itself 2 The Run Time Library RTL 3 Utility programs and units Of these you only need the first two in order to be able to use the compiler In this document we describe the use of the compiler The RTL
26. normally If something went wrong a segmentation fault or so gdb will stop the execution of your program and inform you of this with an appropriate message You can then use the other gdb commands to see what happened Alternatively you can instruct gdb to stop at a certain point in your program with the break command Here is a short list of gdb commands which you are likely to need when debugging your program quit Exits the debugger kill Stops a running program help Gives help on all gdb commands file Loads a new program into the debugger directory Add a new directory to the search path for source files Remark My copy of gdb needs to be added explicitly to the search path otherwise it doesn t find the sources list Lists the program sources per 10 lines As an option you can specify a line number or function name break Sets a breakpoint at a specified line or function awatch Sets a watch point for an expression A watch point stops execution of your program whenever the value of an expression is either read or written 43 8 3 CAVEATS WHEN DEBUGGING WITH GDB for more information see the gdb users guide or use the help function in gdb The appendix II contains a sample init file for gdb which produces good results when debugging Free Pascal programs It is also possible to use RHIDE a text based IDE that uses gdb There is a version of RHIDE available that can work together with
27. of ptop h Writes an overview of the possible parameters and commandline syntax c ptop cfg Read some configuration data from configuration file instead of using the internal defaults then A config file is not required the program can operate without one See also g i ident Sets the number of indent spaces used for BEGIN END and other blocks b bufsize Sets the streaming buffersize to bufsize Default 255 0 is considered non valid and ignored v be verbose Currently only outputs the number of lines read written and some error messages g ptop cfg Writes a default configuration file to be edited to the file ptop cfg 36 7 1 SUPPLIED PROGRAMS Table 7 1 keywords for operators Name of codeword operator casevar in a case label unequal colon becomes delphicomment opencomment or closecomment or semicolon i colon equals openparen closeparen period The ptop configuration file Creating and distributing a configuration file for ptop is not necesarry unless you want to modify the standard behaviour of ptop The configuration file is never preloaded so if you want to use it you should always specify it with a c ptop cfg parameter The structure of a ptop configuration file is a simple buildingblock repeated several 20 30 times for each pascal keyword known to the ptop program see the default configuration file or ptopu pp source to find out which keywords are
28. only explicit if it is a method which is declared as message method handler Error Threadvars can be only static or global Threadvars must be static or global you can t declare a thread local to a procedure Local variables are always local to a thread because every thread has it s own stack and local variables are stored on the stack Fatal Direct assembler not supported for binary output format You can t use direct assembler when using a binary writer choose an other outputformat or use an other assembler reader 69 C 4 TYPE CHECKING ERRORS Warning Don t load OBJPAS unit manual use argmode objfpc or argmode delphi instead You re trying to load the ObjPas unit manual from a uses clause This is not a good idea to do you can better use the mode objfpc or mode delphi directives which load the unit automaticly Error OVERRIDE can t be used in objects Override isn t support for ob jects use VIRTUAL instead to override a method of an anchestor object Error Data types which requires initialization finalization can t be used in variant records Some data type e g ansistring needs initialization finalization code which is implicitly generated by the compiler Such data types can t be used in the variant part of a record C 4 Type checking errors This section lists all errors that can occur when type checking is performed Error Type mismatch This can happen in many cases e The variable you re assi
29. tells the compiler to write errors etc to the file in xxx Flxxx Adds xxx to the library searching path and is passed to the linker FLxxx LINUX only Tells the compiler to use xxx as the dynamic linker Default this is lib Id linux so 2 or lib Id linux so 1 depending on which one is found first 20 5 1 USING THE COMMAND LINE OPTIONS Foxxx Adds xxx to the object file path This path is used when looking for files that need to be linked in Frxxx xxx specifies the file which contain the compiler messages Default the compiler ahs built in messages Specifying this option will override the default messages Fuxxx Add xxx to the unit path Units are loaded from the current directory if they exist and then in the unit path You must always supply the unit path to the system unit FUxxx Tells the compiler to write units in directory xxx instead of the current directory Ixxx Add xxx to the include file search path This path is used when looking for include files This option is obsolite use Fi instead P uses pipes instead of files when assembling This may speed up the compiler on OS 2 and LINUX Only with assemblers such as GNU as that support piping Options controlling the kind of output for more information on these options see also a Tells the compiler not to delete the assembler files it generates not when using the internal assembler This also counts for the possibly generated batch script
30. that are longer than 8 characters will first be looked for with their full length If the unit is not found with this name the name will be truncated to 8 characters and the compiler will look again in the same directories but with the truncated name For instance suppose that the file foo pp needs the unit bar Then the command ppc386 Up Upunits foo pp will tell the compiler to look for the unit bar in the following places 1 In the current directory 2 In the directory where the compile binary is not under LINUX 3 In the parent directory of the current directory 4 In the subdirectory units of the current directory If the compiler finds the unit it needs it will look for the source file of this unit in the same directory where it found the unit If it finds the source of the unit then it will compare the file times If the source file was modified more recent than the unit file the compiler will attempt to recompile the unit with this source file If the compiler doesn t find a compiled version of the unit or when the B option is specified then the compiler will look in the same manner for the unit source file and attempt to recompile it It is recommended to set the unit search path in the configuration file ppc386 cfg If you do this you don t need to specify the unit search path on the command line every time you want to compile something 3 2 Include files If you include files in your source with the I
31. value Error Only virtual methods can be abstract You are declaring a method as abstract when it isn t declared to be virtual Fatal Use of unsupported feature Noute trying to force the compiler into doing something it cannot do yet Error The mix of CLASSES and OBJECTS isn t allowed You cannot de rive objects and classes intertwined That is a class cannot have an object as parent and vice versa Warning Unknown procedure directive had to be ignored arg1 The pro cedure direcive you secified is unknown Recognised procedure directives are cdecl stdcall popstack pascal register export Error absolute can only be associated to ONE variable You cannot spec ify more than one variable before the absolute directive Thus the following construct will provide this error Var Z Longint X Y Longint absolute Z absolute can only be associated a var or const The address of a absolute directive can only point to a variable or constant Therefore the following code will produce this error Procedure X var p longint absolute x Error absolute can only be associated a var or const The address of a absolute directive can only point to a variable or constant Therefore the following code will produce this error Procedure X var p longint absolute x 66 C 3 PARSER MESSAGES Error Only ONE variable can be initialized You cannot specify more than one variable with a initial value in Delphi syntax Er
32. what crsupp crbefore blinbefore dindonkey dindent spbef spaft gobsym inbytab crafter upper lower capital suppress CR before the keyword force CR before keyword doesn t go with crsupp blank line before keyword de indent on associated keywords see below deindent always space before space after Print symbols which follow a keyword but which do not affect layout prints until terminators occur terminators are hard coded in pptop still needs changing indent by tab force CR after keyword prints keyword all uppercase prints keyword all lowercase capitalizes keyword 1st letter uppercase rest lowercase else crbefore dindonkey inbytab upper else if then else mean the following e The keyword this block is about is else because it s on the LEFT side of both equal signs e The option crbefore signals not to allow other code so just spaces before the ELSE keyword on the same line e The option dindonkey de indents if the parser finds any of the keywords in the square brackets line if then else e The option inbytab means indent by a tab e The option upper uppercase the keyword else or Else becomes ELSE Try to play with the configfile step by step until you find the effect you desire The configurability and possibilities of ptop are quite large E g I like all keywords uppercased instead of capitalized so I replaced all capital keywords in the default file by u
33. what has been found because of this feature you must keep the original names when downloading since the script expects this If you run the installation script as the root user you can just accept all installation defaults If you don t run as root you must take care to supply the installation program with directory names where you have write permission as it will attempt to create the directories you specify In principle you can install it wherever you want though At the end of installation the installation program will generate a configuration file for the Free Pascal compiler which reflects the settings that you chose It will install this file in the etc directory if you are not installing as root this will fail and in the directory where you installed the libraries If you want the Free Pascal compiler to use this configuration file it must be present in etc or you can set the environment variable PPC_CONFIG_PATH Under csh you can do this by adding a 2 3 OPTIONAL CONFIGURATION STEPS setenv PPC_CONFIG_PATH usr lib ppc 0 99 1 line to your login file in your home directory see also the next section 2 3 Optional configuration steps You may wish to set some environment variables The Free Pascal compiler recog nizes the following variables e PPC_EXEC_PATH contains the directory where as and Id are default usr bin e PPC_GCCLIB_PATH contains the directory where libgcc a is no default Th
34. with a procedural variable call cannot be inlined Error No code for inline procedure stored The compiler couldn t store code for the inline procedure Error Element zero of an ansi wide or longstring can t be accessed use set length instead You should use setlength to set the length of an ansi wide longstring and length to get the length of such kinf of string Error Include and exclude not implemented in this case include and exclude are only partially implemented for i386 processors and not at all for m68k pro cessors Error Constructors or destructors can not be called inside a with clause Inside a With clause you cannot call a constructor or destructor for the object you have in the with clause Error Cannot call message handler method directly A message method han dler method can t be called directly if it contains an explicit self argument C 7 Unit loading messages This section lists all messages that can occur when the compiler is loading a unit from disk into memory Many of these mesages are informational messages Unitsearch arg1 When you use the vt the compiler tells you where it tries to find unit files PPU Loading arg1 When the vt switch is used the compiler tells you what units it loads PPU Name arg1 When you use the vu flag the unit name is shown PPU Flags arg1 When you use the vu flag the unit flags are shown PPU Cre arg1 When you use the vu flag the unit CRC check is shown
35. 87 hardware like this set 387 N set emu387 c djgpp bin emu387 dxe There is an alternative FP emulator called WMEMU It mimics a real coprocessor more closely 88 WARNING We strongly suggest that you use WMEMU as FPU emulator since emu387 dxe does not emulate all the instructions which are used by the Run Time Libary such as FWAIT Q I have an 80387 emulator installed in my AUTOEXEC BAT but DJGPP compiled floating point programs still doesn t work Why A DJGPP switches the CPU to protected mode and the information needed to emulate the 80387 is different Not to mention that the exceptions never get to the real mode handler You must use emulators which are designed for DJGPP Apart of emu387 and WMEMU the only other emulator known to work with DJGPP is Q87 from QuickWare Q87 is shareware and is available from the QuickWare Web site Q I run DJGPP in an os 2 DOS box and I m told that 08 2 will install its own emulator library if the CPU has no FPU and will transparently execute FPU instructions So why wont DJGPP run floating point code under os 2 on my machine A 08 2 installs an emulator for native os 2 images but does not provide FPU emulation for DOS sessions 89 Appendix F A sample gdb ini file Here you have a sample gdb ini file listing which gives better results when using gdb Under LINUX you should put this in a gdbinit file in your home directory or the current directory set print
36. Free Pascal Users manual Users manual for Free Pascal version 0 99 12 1 6 July 1999 Micha l Van Canneyt Florian Kl mpfl Contents A DOU e computer etting more information 2 nstalling e compile stem requirements oltware requiremen Software requirementy Z 2 Installing the compiler 2 nstalling the compuer NO i o der DOS nstalling under Linux S Optional configuration step esting e comp1ler lie searching KI o 2 Conhguration file 4 ompuing a program OI DUU a unl yreating an executable for GO32V1 and PMO Reducing the size of your progra D 4 D eneral problems 4 Problems you may encounter under DOs PMOD ao Aa A A NN OC en CO CO OH 10 10 12 12 12 13 13 14 14 15 15 16 16 16 17 18 18 18 CONTENTS i ompiler configuratio 19 D Using the command line optiong 0 0 eee 19 ahd Bas ae ee cheno ee ee a ieee eee Oe ee 19 Options for getting feedback 000004 20 Options concerning files and directories 0 20 Options controlling the kind of output 21 eae aes 23 D Using the configuration Did 24 D Variable substitution in path 28 6 Porting rbo Pascal Code 29 0 ings that will not wor 29 D ings which are extra 2 2 ee ee 30 D urbo Pascal compatibility modd osoo a a a 32 8 4 upport for gprof
37. TABLE FOR GO32V1 AND PMODE DJ TARGETS 3 6 Creating an executable for GO32V1 and PMODE DJ targets The GO32V1 platform is officially no longer supported so this section is of interest only to people who wish to make go32V1 binaries anyway GO32V1 When compiling under DOS GO32V2 is the default target However if you use go32V1 using the TGO32V1 switch the compilation process leaves you with a file which you cannot execute right away There are 2 things you can do when compiling has finished The first thing is to use the DOS extender from D J Delorie to execute your program go32 prog This is fine for testing but if you want to use a program regularly it would be easier if you could just type the program name i e prog This can be accomplished by making a DOS executable of your compiled program There two ways to create a DOS executable under DOS only 1 if the GO32 EXE is already installed on the computers where the program should run you must only copy a program called STUB EXE at the begin of the AOUT file This is accomplished with the AOUT2EXE EXE program which comes with the compiler AOQUT2EXE PROG and you get a DOS executable which loads the GO32 EXE automatically the GO32 EXE executable must be in current directory or be in a directory in the PATH variable 2 The second way to create a DOS executable is to put GO32 EXE at the begin ning of the AOUT file To do this at the command prompt type
38. X is the version number of the rpm file If you use debian installation is limited to dpkg i fpc XXX deb Here again XXX is the version number of the deb file You need root access to install these packages The tar file allows you to do an installation if you don t have root permissions When downloading the tar file or the separate files installation is more interac tive In case you downloaded the tar file you should first untar the file in some directory where you have write permission using the following command tar xvf fpc tar We supposed here that you downloaded the file fpc tar somewhere from the Internet The real filename will have some version number in it which we omit here for clarity When the file is untarred you will be left with more archive files and an install program an installation shell script If you downloaded the files as separate files you should at least download the install sh script and the libraries in libs tar gz To install Free Pascal all that you need to do now is give the following command install sh And then you must answer some questions They re very simple they re mainly concerned with 2 things 1 Places where you can install different things 2 Deciding if you want to install certain components such as sources and demo programs The script will automatically detect which components are present and can be installed It will only offer to install
39. an change this behavior by changing the maxunits constant in the files pas file of the compiler and recompiling the compiler Fatal Circular unit reference between argl and arg2 Two units are using each other in the interface part This is only allowed in the implementation part At least one unit must contain the other one in the implementation section Fatal Can t compile unit argl1 no sources available A unit was found that needs to be recompiled but no sources are available Warning Compiling the system unit requires the Us switch When recom piling the system unit it needs special treatment the Us must be specified Fatal There were arg1 errors compiling module stopping When the com piler encounters a fatal error or too many errors in a module then it stops with this message Load from arg1 arg2 unit arg3 When you use the vu flag which unit is loaded from which unit is shown Recompiling arg1 checksum changed for arg2 Recompiling argl source found only When you use the vu flag these mes sages tell you why the current unit is recompiled 77 C 8 COMMAND LINE HANDLING ERRORS Recompiling unit static lib is older than ppufile When you use the vu flag the compiler warns if the static library of the unit are older than the unit file itself Recompiling unit shared lib is older than ppufile When you use the vu flag the compiler warns if the shared library of the unit are older than the unit file it
40. annot nest response files with the file command line option Fatal No source file name in command line The compiler expects a source file name on the command line Error Illegal parameter argl You specified an unknown option Hint writes help pages When an unknown option is given this message is diplayed Fatal Too many config files nested You can only nest up to 16 config files Fatal Unable to open file arg1 The option file cannot be found Note Reading further options from arg1 Displayed when you have notes turned on and the compiler switches to another options file 78 C 9 ASSEMBLER READER ERRORS Warning Target is already set to argl Displayed if more than one T option is specified Warning Shared libs not supported on DOS platform reverting to static If you specify CD for the DOS platform this message is displayed The com piler supports only static libraries under DOS Fatal too many IF N DEFs the IF N DEF statements in the options file are not balanced with the ENDIF statements Fatal too many EN DIS the IF N DEF statements in the options file are not balanced with the ENDIF statements Fatal open conditional at the end of the file the IF N DEF statements in the options file are not balanced with the ENDIF statements Warning Debug information generation is not supported by this executable It is possible to have a compiler executable that doesn t support the genera tion of debuggi
41. aren t balanced e An include file ends in the middle of a statement e A comment wasn t closed Fatal String exceeds line You forgot probably to include the closing ma string so it occupies multiple lines Fatal illegal character An illegal character was encountered in the input file Fatal Syntax error argl expected but arg2 found This indicates that the compiler expected a different token than the one you typed It can occur almost everywhere where you make a mistake against the pascal language Start reading includefile arg1 When you provide the vt switch the compiler tells you when it starts reading an included file Warning Comment level arg1 found When the vw switch is used then the compiler warns you if it finds nested comments Nested comments are not allowed in Turbo Pascal and can be a possible source of errors Note argF directive FAR ignored The FAR directive is a 16 bit construction which is recorgnised but ignored by the compiler since it produces 32 bit code Note Stack check is global under Linux Stack checking with the Cs switch is ignored under LINUX since LINUX does this for you Only displayed when vn is used Note Ignored compiler switch arg1 With vn on the compiler warns if it ig nores a switch Warning Illegal compiler switch arg1 You included a compiler switch i e which the compiler doesn t know Warning This compiler switch has a global effect When vw is used the
42. arg1 found When you turn on conditional messages vc the compiler tells you where it encounters conditional statements IFDEF arg1 found arg2 When you turn on conditional messages vc the com piler tells you where it encounters conditional statements IFOPT arg1 found arg2 When you turn on conditional messages vc the com piler tells you where it encounters conditional statements IF arg1 found arg2 When you turn on conditional messages vc the compiler tells you where it encounters conditional statements IFNDEF arg1 found arg2 When you turn on conditional messages vc the compiler tells you where it encounters conditional statements ELSE arg1 found arg2 When you turn on conditional messages vc the com piler tells you where it encounters conditional statements Skipping until When you turn on conditional messages vc the compiler tells you where it encounters conditional statements and whether it is skipping or compiling parts Info Press jreturn to continue When the vi switch is used the compiler stops compilation and waits for the Enter key to be pressed when it encounters a STOP directive Warning Unsupported switch arg1 When warings are turned on vw the compiler warns you about unsupported switches This means that the switch is used in Delphi or Turbo Pascal but not in Free Pascal Warning Illegal compiler directive arg1 When warings are turned on vw the compiler warns you about unreco
43. as directory separators is ir relevant the compiler will convert to whatever character is used on the current operating system Examples will be given using slashes since this avoids problems on LINUX Command line files The file that you specify on the command line such as in ppc386 foo pp will be looked for ONLY in the current directory If you specify a directory in the filename then the compiler will look in that directory ppc386 subdir foo pp will look for foo pp in the subdirectory subdir of the current directory Under LINUX the name of this file is case sensitive under other operating systems Dos WInDows NT 08 2 this is not the case 12 3 2 INCLUDE FILES Unit files When you compile a unit or program that needs other units the compiler will look for compiled versions of these units in the following way 1 It will look in the current directory 2 It will look in the directory where the compiler binary is not under LINUX 3 It will look in all the directories specified in the unit search path You can add a directory to the unit search path with the Up or Fu options See See RI Every occurrence of one of those options will append a directory to the unit search path On LINUX the compiler will first convert the filename of a unit to all lowercase This is necessary since Pascal is case independent and the statements Uses Uniti or uses unit1 should have the same effect Also unit names
44. at the L Longint begin end e recursive function calls are handled dfferently Consider the following example Function expr Longint begin Expr L Writeln Expr end In Turbo Pascal compatibility mode the function will be called recursively when the writeln statement is processed In Free Pascal the function result will be printed In order to call the function recusively under Free Pascal you need to implement it as follows 32 6 3 TURBO PASCAL COMPATIBILITY MODE Function expr Longint begin Expr L Writeln Expr end Any text after the final End processed too statement is ignored Normally this text is You cannot assign procedural variables to void pointers The operator is typed when applied on procedures You cannot nest comments 33 Chapter 7 Utilities and units that come with Free Pascal Besides the compiler and the Run Time Library Free Pascal comes with some utility programs and units Here we list these programs and units 7 1 Supplied programs ppudump program ppudump is a program which shows the contents of a Free Pascal unit It is dis tributed with the compiler You can just issue the following command ppudump options foo ppu to display the contents of the foo ppu unit You can specify multiple files on the command line The options can be used to change the verbosity of the display By default all available information is displayed Y
45. ckets graph ports This unit provides access to the LINUX operating system It provides most file and I O handling routines that you may need It implements most of the standard C library constructs that you will find on a Unix system If you do a lot of disk file operations the use of this unit is recommended over the one you use under Dos This unit provides an interface to the standard Unix printing mechanism This unit gives you the GNU getopts command line arguments handling mech anism It also supports long options This unit provides support for mmx extensions in your code This unit gives you access to sockets and TCP IP programming Is an implementation of Borlands graph unit which works on the Linux con sole It s implementation is fairly complete the only non functional things are the fillpatterns and line styles It uses the libvga and libvgagl graphics libraries so you need these installed for this unit to work Also programs using this library need to be run as root or setuid root and hence are a potential security risk This implements the various port constructs These are provided for com patibility only and it is not recommended to use them extensively Programs using this construct must be run as ruit or setuid root and are a serious security risk on your system 41 Chapter 8 Debugging your Programs Free Pascal supports debug information for the GNU debugger gdb This chapter describes short
46. ctions Close Read Write Seek EOf FilePos FileSize Flush BlockRead and BlockWrite if the file isn t open 104 File not open for input Reported by Read BlockRead Eof Eoln SeekEof or SeekEoln if the file isn t opened with Reset 105 File not open for output Reported by write if a text file isn t opened with Rewrite 106 Invalid numeric format Reported when a non numerice value is read from a text file when a numeric value was expected 150 Disk is write protected Critical error DOS only 151 Bad drive request struct length Critical error DOs only 152 Drive not ready Critical error DOS only 154 CRC error in data Critical error DOS only 156 Disk seek error Critical error DOS only 157 Unknown media type Critical error DOS only 158 Sector Not Found Critical error DOS only 159 Printer out of paper Critical error DOS only 160 Device write fault Critical error DOS only 161 Device read fault Critical error Dos only 162 Hardware failure Critical error DOS only 200 Division by zero You are dividing a number by zero 201 Range check error If you compiled your program with range checking on then you can get this error in the following cases 1 An array was accessed with an index outside its declared range 2 You re trying to assign a value to a variable outside its range for instance a enumerated type 202 Stack overflow error The stack has grown beyond itss maximum size
47. d GOTO Sh Use ansistrings Si support C styled INLINE Sm support macros like C global So tries to be TP BP 7 0 compatible Sp tries to be gpc compatible Ss constructor name must be init destructor must be done St allow static keyword in objects s don t call assembler and linker only with a u lt x gt undefines the symbol lt x gt U unit options Un don t check the unit name Us compile a system unit v lt x gt Be verbose lt x gt is a combination of the following letters e Show errors default d Show debug info w Show warnings u Show unit info n Show notes t Show tried used files h Show hints m Show defined macros i Show general info p Show compiled procedures 1 Show linenumbers c Show conditionals a Show everything O Show nothing except errors b Show all procedure r Rhide GCC compatibility mode declarations if an error x Executable info Win32 only occurs X executable options XD link with dynamic libraries defines FPC_LINK_DYNAMIC Xs strip all symbols from executable XS link with static libraries defines FPC_LINK_STATIC Processor specific options A lt x gt output format Ao coff file using GNU AS 53 Anasmcoff Anasmelf Anasmobj Amasm Atasm R lt x gt assembler re Ratt Rintel Rdirect 0 lt x gt optimization 0g 0G 0r 0u 01 02 03 0p lt x gt T lt x gt Target opera TG032V1 TG032V2 TLINUX TOS2 TWin32
48. d Intel styled assembler this is reported when you try to use a non label identifier with a 07 prefix Internal error in Findtype Internal Error in ConcatOpcode Internal Errror converting binary Internal Errror converting hexadecimal Internal Errror converting octal Internal Error in BuildScaling Internal Error in BuildConstant internal error in BuildReference internal error in HandleExtend Internal error in ConcatLabeledInstr These errors should never occur if they do then you have found a new bug in the assembler parsers Please contact one of the developers Opcode not in table operands not checked This warning only occurs when compiling the system unit or related files No checking is performed on the operands of the opcodes CODE and DATA not supported This Turbo Pascal construct is not sup ported SEG and OFFSET not supported This Turbo Pascal construct is not supported 80 C 9 ASSEMBLER READER ERRORS Modulo not supported Modulo constant operation is not supported Floating point binary representation ignored Floating point hexadecimal representation ignored Floating point octal representation ignored These warnings occur when a float ing point constant are declared in a base other then decimal No conversion can be done on these formats You should use a decimal representation in stead Identifier supposed external This warning occurs when a symbol is not found in the symolb table it is t
49. demangle off set gnutarget auto set verbose on set complaints 1000 dir rtl dosv2 set language c set print vtbl on set print object on set print sym on set print pretty on disp i eip define pst set pos amp arg0 set strlen byte pos print char amp arg0 st strlent1 end document pst Print out a pascal string end 90
50. e the same mangled name This is important when using overloaded functions but should produce no error Error With can not be used for variables in a different segment With stores a variable locally on the stack but this is not possible if the variable belongs to another segment Error function nesting 31 You can nest function definitions only 31 times Error range check error while evaluating constants The constants are out of their allowed range Warning range check error while evaluating constants The constants are out of their allowed range Error duplicate case label You are specifying the same label 2 times in a case statement Error Upper bound of case range is less than lower bound The upper bound of a case label is less than the lower bound and this is useless Error typed constants of classes are not allowed You cannot declare a con stant of type class or object Error functions variables of overloaded functions are not allowed You are trying to assign an overloaded function to a procedural variable This isn t allowed Error string length must be a value from 1 to 255 The length of a string in Pascal is limited to 255 characters You are trying to declare a string with length lower than 1 or greater than 255 This is not true for Longstrings and AnsiStrings Warning use extended syntax of NEW and DISPOSE for instances of objects If you have a pointer a to a class type then the statement new a will not
51. e used i e appears in the right hand side of an expression when it wasn t initialized first i e appeared in the left hand side of an assigment 73 C 6 CODE GENERATOR MESSAGES Error identifier idents no member argl When using the extended syntax of new you must specify the constructor method of the class you are trying to create The procedure you specified does not exist Found declaration arg1 You get this when you use the vb switch In case an overloaded procedure is not found then all candidate overloaded procedures are listed with their parameter lists C 6 Code generator messages This section lists all messages that can be displayed if the code generator encounters an error condition Error BREAK not allowed You re trying to use break outside a loop construc tion Error CONTINUE not allowed You re trying to use continue outside a loop construction Error Expression too complicated FPU stack overflow Your expression is too long for the compiler You should try dividing the construct over multiple assignments Error Illegal expression This can occur under many circumstances Mostly when trying to evaluate constant expressions Error Invalid integer expression You made an expression which isn t an inte ger and the compiler expects the result to be an integer Error Illegal qualifier One of the following is happening e You re trying to access a field of a variable that is not a record e You
52. g system Dos It provides almost the same functionality as the Turbo Pascal unit printer This unit provides all you need for rudimentary access to the printer getopts This unit gives you the GNU getopts command line arguments handling mech anism It also supports long options crt This unit provides basic screen handling routines It provides the same func tionality as the Turbo Pascal CRT unit graph This unit provides basic graphics handling with routines to draw lines on the screen display texts etc It provides the same functions as the Turbo Pascal unit go32 This unit provides access to possibilities of the GO32 DOS extender emu387 This unit provides support for the coprocessor emulator mmx This unit provides support for mmx extensions in your code Under Linux strings This unit provides basic string handling routines for the PChar type compa rable to similar routines in standard C libraries objects This unit provides basic routines for handling objects crt This unit provides basic screen handling routines It provides the same func tionality Turbo Pascal CRT unit It works on any terminal which supports the vt100 escape sequences dos This unit provides an emulation of the same unit under Dos It is intended primarily for easy porting of Pascal programs from DOS to LINUX For good performance however it is recommended to use the linux unit 40 7 2 SUPPLIED UNITS linux printer getopts mmx so
53. gning to is of a different type than the expression in the assignment e You are calling a function or procedure with parameters that are incom patible with the parameters in the function or procedure definition Error Incompatible types got arg1 expected arg2 There is no con version possible between the two types Another possiblity is that they are declared in different declarations Var A1 Array 1 10 Of Integer A2 Array 1 10 Of Integer Begin A1 A2 This statement gives also this error it is due the strict type checking of pascal End Error Type mismatch between argl and arg2 The types are not equal Error Integer expression expected The compiler expects an expression of type integer but gets a different type Error Ordinal expression expected The expression must be of ordinal type i e maximum a Longint This happens for instance when you specify a second argument to Inc or Dec that doesn t evaluate to an ordinal value Error Type identifier expected The identifier is not a type or you forgot to supply a type identifier Error Variable identifier expected This happens when you pass a constant to a Inc var or Dec procedure You can only pass variables as arguments to these functions Error pointer type expected The variable or expression isn t of the type pointer This happens when you pass a variable that isn t a pointer to New or Dispose 70 C 4 TYPE CHECKING ERRORS Er
54. gnised switches For a list of recognised switches Back in arg1 When you use vt the compiler tells you when it has finished reading an include file Warning Unsupported application type argl You get this warning ff you specify an unknown application type with the directive APPTYPE Warning APPTYPE isn t support by the target OS The APPTYPE di rective is supported by win32 applications only Warning Unsupported assembler style specified arg1 When you specify an assembler mode with the ASMMODE xxx the compiler didn t recognize the mode you specified 59 C 3 PARSER MESSAGES Warning ASM reader switch is not possible inside asm statement argl It is not possible to switch from one assembler reader to another inside an ass mebler block The new reader will be used for next assembler statement only Error Wrong switch toggle use ON OFF or You need to use ON or OFF or a or to toggle the switch Error Resource files are not supported for this target The target you are compiling for doesn t support Resource files The only target which can use resource files is Win32 C 3 Parser messages This section lists all parser messages The parser takes care of the semantics of you language i e it determines if your pascal constructs are correct Error Parser Syntax Error An error against the Turbo Pascal language was encountered This happens typically when an illegal character is found in the source
55. hat some units aren t found or compile incorrectly due to missing conditionals etc If all went well the executable now contains the necessary information with which you can debug it using GNU gdb 1A good reason not to include debug information in an executable you plan to distribute 42 8 2 USING GDB TO DEBUG YOUR PROGRAM 8 2 Using gdb to debug your program To use gdb to debug your program you can start the debugger and give it as an option the full name of your program gdb hello Or under Dos gdb hello exe This starts the debugger and the debugger immediately loads your program into memory but it does not run the program yet Instead you are presented with the following more or less message followed by the gdb prompt gdb GDB is free software and you are welcome to distribute copies of it under certain conditions type show copying to see the conditions There is absolutely no warranty for GDB type show warranty for details GDB 4 15 1 i486 slackware linux Copyright 1995 Free Software Foundation Inc gdb To start the program you can use the run command You can optionally specify command line parameters which will then be fed to your program for example gdb run option anotheroption needed_argument If your program runs without problems gdb will inform you of this and return the exit code of your program If the exit code was zero then the message Program exited
56. herefore considered external Functions with void return value can t return any value in asm code Only routines with a return value can have a return value set Error in binary constant Error in octal constant Error in hexadecimal constant Error in integer constant These errors are reported when you tried using an invalid constant expression or that the value is out of range Invalid labeled opcode Asm syntax error error in reference Invalid Opcode Invalid combination of opcode and operands Invalid size in reference Invalid middle sized operand Invalid three operand opcode Assembler syntax error Invalid operand type You tried using an invalid combination of opcode and operands check the syntax and if you are sure it is correct please contact one of the developers Unknown identifier The identifier you are trying to access does not exist or is not within the current scope Trying to define an index register more than once Trying to define a segment register twice Trying to define a base register twice You are trying to define an index segment register more then once Invalid field specifier The record or object field you are trying to access does not exist or is incorrect Invalid scaling factor Invalid scaling value 81 C 9 ASSEMBLER READER ERRORS Scaling value only allowed with index Allowed scaling values are 1 2 4 or 8 Cannot use SELF outside a method You are trying to access the SELF iden t
57. hod of non virtual method should be non virtual arg1 If you declare overloaded methods in a class then they should either all be virtual or none You shouldn t mix them Error overloaded methods which are virtual must have the same return type argl If you declare virtual overloaded methods in a class definition they must have the same return type Error EXPORT declared functions can t be nested You cannot declare a function or procedure within a function or procedure that was declared as an export procedure Error methods can t be EXPORTed You cannot declare a procedure that is a method for an object as exported That is your methods cannot be called from a C program 64 C 3 PARSER MESSAGES Error call by var parameters have to match exactly When calling a func tion declared with var parameters the variables in the function call must be of exactly the same type There is no automatic type conversion Error Class isn t a parent class of the current class When calling inherited methods you are trying to call a method of a strange class You can only call an inherited method of a parent class Error SELF is only allowed in methods You are trying to use the self pa rameter outside an object s method Only methods get passed the self pa rameters Error methods can be only in other methods called direct with type identifier of the class A construction like sometype somemethod is only allowed in a method Er
58. ictly speaking isn t required for the execution of it The surplus of information can be removed with a small program called strip It comes with the GO32 development environment under DOS and is standard on LINUX machines where you can do development The usage is simple Just type strip prog On the command line and the strip program will remove all unnecessary information from your program This can lead to size reductions of up to 30 remark in the WIN32 32 version strip is called stripw You can use the Xs switch to let the compiler do this stripping automatically at program compile time the switch has no effect when compiling units Another technique to reduce the size of a program is to use smartlinking Normally units including the system unit are linked in as a whole It is however possible to compile units such that the can be smartlinked This means that only the functions and procedures are linked in your program leaving out any unnecessary code This technique is described in full in the programmers guide 17 Chapter 4 Compiling problems 4 1 General problems e O error 2 at Under LINUX you can get this message at compiler startup It means typically that the compiler doesn t find the error definitions file You can correct this mistake with the Fr option under LINUX See e Error File not found xxx or Error couldn t compile unit xxx This typically happens when your unit path isn t set
59. ifier for objects outside a method Invalid combination of prefix and opcode This opcode cannot be prefixed by this instruction Invalid combination of override and opcode This opcode cannot be overri den by this combination Too many operands on line At most three operand instructions exist on the m68k and i386 you are probably trying to use an invalid syntax for this opcode Duplicate local symbol You are trying to redefine a local symbol such as a local label Unknown label identifer Undefined local symbol local symbol not found inside asm statement This label does not seem to have been defined in the current scope Assemble node syntax error Not a directive or local symbol The assembler statement is invalid or you are not using a recognized directive 1386 specific errors repeat prefix and a segment override on lt i386 A problem with interrupts and a prefix instruction may occur and may cause false results on 386 and earlier computers Fwait can cause emulation problems with emu387 This warning is reported when using the FWAIT instruction it can cause emulation problems on sys tems which use the em387 dxe emulator You need GNU as version j 2 81 to compile this MMX code MMX as sembler code can only be compiled using GAS v2 8 1 or later NEAR ignored FAR ignored NEAR and FAR are ignored in the intel assemblers but are still ac cepted for compatiblity with the 16 bit code model Invalid size for MOVSX
60. in the compiler to prevent buffer overflows This is shown as a warning i e when the vw switch is used Error ENDIF without IF N DEF Your IFDEF and SENDIF state ments aren t balanced Fatal User defined arg1 A user defined fatal error occurred see also the Error User defined arg1 A user defined error occurred see also the Warning User defined argl A user defined warning occurred see also the o o de Note User defined argl A user defined note was encountered see also the o OG de Hint User defined argl A user defined hint was encountered see also the Programmers guide Info User defined arg1 User defined information was encountered see also the Programmers guide Error Keyword redefined as macro has no effect You cannot redefine key words with macros 58 C 2 SCANNER MESSAGES Fatal Macro buffer overflow while reading or expanding a macro Your macro or it s result was too long for the compiler Warning Extension of macros exceeds a deep of 16 When expanding a macro macros have been nested to a level of 16 The compiler will expand no further since this may be a sign that recursion is used Error compiler switches aren t allowed in styled comments Compiler switches should always be between comment delimiters Handling switch arg1 When you set debugging info on vd the compiler tells you when it is evaluating conditional compile statements ENDIF
61. ind of executable should be generated the parameter x can be one of the following e c LINUX only Link with the C library You should only use this when you start to port Free Pascal to another operating system e D Link with dynamic libraries defines the FPC_LLINK_DYNAMIC symbol e s Strip the symbols from the executable e S Link with static libraries defines the FPC_LINK_STATIC symbol Options concerning the sources language options for more information on these options see also Rxxx Specifies what kind of assembler you use in your asm assembler code blocks Here xxx is one of the following att asm blocks contain AT amp T style assembler This is the default style intel asm blocks contain Intel style assembler direct asm blocks should be copied as is in the assembler only replacing certain variables file S2 Switch on Delphi 2 extensions This is different from Sd because some Free Pascal constructs are still available to you Sc Support C style operators i e Ze and Sd Tells the compiler to be Delphi compatible This is more strict than the S2 option since some fpc extensions are switched off Se The compiler stops after the first error Normally the compiler tries to continue compiling after an error until 50 errors are reached or a fatal error is reached and then it stops With this switch the compiler will stop after the first error 23 5 2 USING THE CONFIGURATION FILE
62. initialize the class i e the constructor isn t called although space will be allocated you should issue the new a init statement This will allocate space and call the constructor of the class Warning use of NEW or DISPOSE for untyped pointers is meaningless Error use of NEW or DISPOSE is not possible for untyped pointers You cannot use new p or dispose p if p is an untyped pointer because no size is associated to an untyped pointer Accepted for compatibility in tp and delphi modes Error class identifier expected This happens when the compiler scans a pro cedure declaration that contains a dot i e a object or class method but the type in front of the dot is not a known type 62 C 3 PARSER MESSAGES Error type identifier not allowed here You cannot use a type inside an ex pression Error method identifier expected This identifier is not a method This hap pens when the compiler scans a procedure declaration that contains a dot i e a object or class method but the procedure name is not a procedure of this type Error function header doesn t match any method of this class This iden tifier is not a method This happens when the compiler scans a procedure dec laration that contains a dot i e a object or class method but the procedure name is not a procedure of this type procedure function argl When using the vp switch the compiler tells you when it starts processing a procedure or function imple
63. is if for LINUX only e PPC_CONFIG_PATH specifies an alternate path to find ppc386 cfg default under LINUX is etc e PPC_ERROR_FILE specifies the path and name of the error definition file de fault usr lib fpc errorE msg These locations are however set in the sample configuration file which is built at the end of the installation process except for the PPC_CONFIG_PATH variable which you must set if you didn t install things in the default places finally Also distributed in Free Pascal isa README file It contains the latest instructions for installing Free Pascal and should always be read first 2 4 Testing the compiler After the installation is completed and the environment variables are set as described above your first program can be compiled Included in the Free Pascal distribution are some demonstration programs showing what the compiler can do You can test if the compiler functions correctly by trying to compile these programs The compiler is called e PPC386 EXE under Dos and e ppc386 under LINUX To compile a program e g demo hello pp simply type ppc386 hello at the command prompt If you don t have a configuration file then you may need to tell the compiler where it can find the units for instance as follows ppc386 Upc pp rtl dos go32v2 hello under DOS and under LINUX you could type 10 2 4 TESTING THE COMPILER ppc386 Up usr lib fpc 0 99 7 linuxunits hello This is
64. is pro cedure directive is not allowed in the interface section of a unit You can only use it in the implementation section Error Procedure directive argl not allowed in implementation section This procedure directive is not defined in the implementation section of a unit You can only use it in the interface section Error Procedure directive arg1 not allowed in procvar declaration This pro cedure directive cannot be part of a procedural of function type declaration Error Function is already declared Public Forward arg1 You will get this error if a function is defined as forward twice Or it is once in the interface section and once as a forward declaration in the implmentation section Error Can t use both EXPORT and EXTERNAL These two procedure di rectives are mutually exclusive Error NAME keyword expected The definition of an external variable needs a name clause Warning argl not yet supported inside inline procedure function Inline procedures don t support this declaration Warning Inlining disabled Inlining of procedures is disabled Info Writing Browser log arg1 When information messages are on the com piler warns you when it writes the browser log generated with the Y switch Hint may be pointer dereference is missing The compiler thinks that a pointer may need a dereference Fatal Selected assembler reader not supported The selected assembler reader with ASMMODE xxx is not supported The c
65. ith the Sg switch By default label and goto aren t supported Error Label not found A goto label was encountered but the label isn t de clared Error identifier isn t a label The identifier specified after the goto isn t of type label Error label already defined You are defining a label twice You can define a label only once Error illegal type declaration of set elements The declaration of a set con tains an invalid type definition Error Forward class definition not resolved arg1 You declared a class but you didn t implement it Hint Parameter not used arg1 This is a warning The identifier was declared locally or globally but wasn t used locally or globally Note Local variable not used arg1 You have declared but not used a variable in a procedure or function implementation Error Set type expected The variable or expression isn t of type set This happens in an in statement Warning Function result does not seem to be set You can get this warning if the compiler thinks that a function return value is not set This will not be displayed for assembler procedures or procedures that contain assembler blocks Error Unknown record field identifier arg1 The field doesn t exist in the record definition Warning Local variable arg1 does not seem to be initialized Warning Variable arg1 does not seem to be initialized These messages are displayed if the compiler thinks that a variable will b
66. le above would work with TP but the compiler would assume that the a gt 4 is a recursive call To do a recursive call in this you must append behind the function name function a longint begin a 12 this is the recursive call if a gt 4 then begin 30 6 2 THINGS WHICH ARE EXTRA 3 00 end end There is partial support of Delphi constructs see the for more information on this The exit call accepts a return value for functions function a longint begin a 12 if a gt 4 then begin exit a 67 function result upon exit is a 67 end end Free Pascal supports function overloading That is you can define many functions with the same name but with different arguments For example procedure DoSomething a longint begin Avena tt end procedure DoSomething a real begin EEN end You can then call procedure DoSomething with an argument of type Longint or Real This feature has the consequence that a previously declared function must always be defined with the header completely the same procedure x v longint forward procedure x This will overload the previously declared x begin Lote end This construction will generate a compiler error because the compiler didn t find a definition of procedure x v longint Instead you should de fine your procedure x as procedure x v longint This correctly defines the previously declared x
67. legal constant passed to internal math function The constant ar gument passed to a In or sqrt function is out of the definition range of these functions Error Can t get the address of constants It s not possible to get the address of a constant because they aren t stored in memory you can try making it a typed constant C 5 Symbol handling This section lists all the messages that concern the handling of symbols This means all things that have to do with procedure and variable names Error Identifier not found arg1 The compiler doesn t know this symbol Usu ally happens when you misspel the name of a variable or procedure or when you forgot to declare a variable Fatal Internal Error in SymTableStack An internal error occurred in the compiler If you encounter such an error please contact the developers and try to provide an exact description of the circumstances in which the error occurs Error Duplicate identifier arg1 The identifier was already declared in the cur rent scope Hint Identifier already defined in arg1 at line arg2 The identifier was al ready declared in a previous scope Error Unknown identifier arg1 The identifier encountered hasn t been declared or is used outside the scope where it s defined Error Forward declaration not solved arg1 This can happen in two cases e This happens when you declare a function in the interface part or with a forward directive but do not implement it
68. legant way this program does the same thing as the previous one It also suffers from the same drawback namely the limited length of the value field of the datarec This drawback can be remedied by redefining datarec as follows type datarec record name value pchar end and assigning at run time enough space to keep the contents of the value field This can be done with a getmem data nrdata value needed_number_of_bytes call After that you can do a strlcopy data nrdata value p needed_number_of_bytes to copy the data into place You may have noticed the following unorthodox call inc longint p Free Pascal doesn t give you pointer arithmetic as in C However longints and pointers have the same length namely 4 bytes Doing a type cast to a longint allows you to do arithmetic on the pointer Note however that this is a non portable call This may work on the 1386 processor but not on a ALPHA processor where a pointer is 8 bytes long This will be remedied in future releases of Free Pascal 9 2 Producing output The previous section concentrated mostly on getting input from the web server To send the reply to the server you don t need to do anything special You just print your data on standard output and the Web server will intercept this and send your output to the WWW client waiting for it You can print anything you want the only thing you must take care of is that you supply a Contents ty
69. ler expression is too big to evaluate by the constant parser Try reducing the number of terms Invalid numeric format in asm evaluator This fatal error is reported when a non numeric value is detected by the constant parser Normally this error should never occur 79 C 9 ASSEMBLER READER ERRORS Invalid Operator in asm evaluator This fatal error is reported when a math ematical operator is detected by the constant parser Normally this error should never occur Unknown error in asm evaluator This fatal error is reported when an internal error is detected by the constant parser Normally this error should never occur Invalid numeric value This warning is emitted when a conversion from octal binary or hexadecimal to decimal is outside of the supported range Escape sequence ignored This error is emitted when a non ANSI C escape se quence is detected in a C string Asm syntax error Prefix not found This occurs when trying to use a non valid prefix instruction Asm syntax error Trying to add more than one prefix This occurs when you try to add more than one prefix instruction Asm syntax error Opcode not found You have tried to use an unsupported or unknown opcode Constant value out of bounds This error is reported when the constant parser determines that the value you are using is out of bounds either with the opcode or with the constant declaration used Non label pattern contains This only applied to the m68k an
70. ly how to use this feature It doesn t attempt to describe completely the GNU debugger however For more information on the workings of the GNU debugger see the gdb users guide Free Pascal also suports gprof the GNU profiler see section 8 4 for more information on profiling 8 1 Compiling your program with debugger sup port First of all you must be sure that the compiler is compiled with debugging support Unfortunately there is no way to check this at run time except by trying to compile a program with debugging support To compile a program with debugging support just specify the g option on the command line as follows ppc386 g hello pp This will generate debugging information in the executable from your program You will notice that the size of the executable increases substantially because of bid Note that the above will only generate debug information for the code that has been generated when compiling hello pp This means that if you used some units the system unit for instance which were not compiled with debugging support no debugging support will be available for the code in these units There are 2 solutions for this problem 1 Recompile all units manually with the g option 2 Specify the build option B when compiling with debugging support This will recompile all units and insert debugging information in each of the units The second option may have undesirable side effects It may be t
71. mentation Error Illegal floating point constant The compiler expects a floating point expression and gets something else Error FAIL can be used in constructors only You are using the FAIL in struction outside a constructor method Error Destructors can t have parameters You are declaring a destructor with a parameter list Destructor methods cannot have parameters Error Only class methods can be referred with class references This er ror occurs in a situation like the following Type Tclass Class of Tobject Var C TClass begin C free Free is not a class method and hence cannot be called with a class reference Error Only class methods can be accessed in class methods This is related to the previous error You cannot call a method of an object from a inside a class method The following code would produce this error class procedure tobject x begin free Because free is a normal method of a class it cannot be called from a class method Error Constant and CASE types do not match One of the labels is not of the same type as the case variable 63 C 3 PARSER MESSAGES Error The symbol can t be exported from a library You can only export procedures and functions when you write a library You cannot export vari ables or constants Warning An inherited method is hidden by argl A method that is declared virtual in a parent class should be overridden in the descendent class with the override di
72. mpiler doesn t support C styled inlining by default 60 will be effective only for ne C 3 PARSER MESSAGES Warning Private methods shouldn t be VIRTUAL You declared a method in the private part of a object class as virtual This is not allowed Private methods cannot be overridden anyway Warning Constructor should be public Constructors must be in the public part of an object class declaration Warning Destructor should be public Destructors must be in the public part of an object class declaration Note Class should have one destructor only You can declare only one de structor for a class Error Local class definitions are not allowed Classes must be defined glob ally They cannot be defined inside a procedure or function Fatal Anonym class definitions are not allowed An invalid object class dec laration was encountered i e an object or class without methods that isn t derived from another object or class For example Type o object a longint end will trigger this error Error The object argl has no VMT Error Illegal parameter list You are calling a function with parameters that are of a different type than the declared parameters of the function Error Wrong parameter type specified for arg no argl There is an error in the parameter list of the function or procedure The compiler cannot de termine the error more accurate than this Error Wrong amount of parameters
73. n fact no such property in the parent class Error Only one default property is allowed found inherited default property in class arg1 You specified a property as Default but a parent class already has a default property and a class can have only one default property Error The default property must be an array property Only array prop erties of classes can be made default properties Error Virtual constructors are only supported in class object model You cannot have virtual constructors in objects You can only have them in classes Error No default property available You try to access a default property of a class but this class or one of it s ancestors doesn t have a default property Error The class can t have a published section use the argM switch If you want a published section in a class definition you must use the M switch whch turns on generation of type information Error Forward declaration of class arg1 must be resolved here to use the class as ancestor To be able to use an object as an ancestor object it must be defined first This error occurs in the following situation 67 C 3 PARSER MESSAGES Type ParentClas Class ChildClass Class ParentClass end Where ParentClass is declared but not defined Error Local operators not supported You cannot overload locally i e inside procedures or function definitions Error Procedure directive arg1 not allowed in interface section Th
74. ncatenation of the object type and the function name separated by two underscore characters For example the method TPoint Draw would be converted to TPOINT__DRAW and could be stopped at with 44 8 4 SUPPORT FOR GPROF THE GNU PROFILER break TPOINT__DRAW 6 Global overloaded functions confuse gdb because they have the same name Thus you cannot set a breakpoint at an overloaded function unless you know it s line number in which case you can set a breakpoint at the starting linenumber of the function 8 4 Support for gprof the gnu profiler You can compile your programs with profiling support for this you just have to use the compiler switch pg The compiler wil insert the necessary stuff for profiling When you have done this you can run your program as you normally would run it yourexe Where yourexe is the name of your executable When your program finishes a file called gmon out is generated Then you can start the profiler to see the output You can better redirect the output to a file becuase it could be quite a lot gprof yourexe gt profile log Hint you can use the Hat option to reduce the amount of output of gprof It will then only output the information about the timings For more information on the GNU profiler gprof see its manual 45 Chapter 9 CGI programming in Free Pascal In these days of heavy WWW traffic on the Internet CGI scripts have become an important topic in computer prog
75. ng info If you use such an executable with the g switch this warning will be displayed Hint Try recompiling with dGDB It is possible to have a compiler executable that doesn t support the generation of debugging info If you use such an ex ecutable with the g switch this warning will be displayed Error You are using the obsolete switch arg1 this warns you when you use a switch that is not needed supported anymore It is recommended that you remove the switch to overcome problems in the future when the switch meaning may change Error You are using the obsolete switch arg1 please use arg2 this warns you when you use a switch that is not supported anymore You must now use the second switch instead It is recommended that you change the switch to overcome problems in the future when the switch meaning may change Note Switching assembler to default source writing assembler this noti fies you that the assembler has been changed because you used the a switch which can t be used with a binary assembler writer C 9 Assembler reader errors This section lists the errors that are generated by the inline assembler reader They are not the messages of the assembler itself General assembler errors Divide by zero in asm evaluator This fatal error is reported when a constant assembler expressions does a division by zero Evaluator stack overflow Evaluator stack underflow These fatal errors are reported when a constant assemb
76. nit Then the object file contains the code of the unit and will be linked in any program that uses the unit you compiled so you shouldn t remove it 3 5 Compiling a unit Compiling a unit is not essentially different from compiling a program The differ ence is mainly that the linker isn t called in this case To compile a unit in the file foo pp just type ppc386 foo Recall the remark about file extensions in the previous section When all went well you will be left with 2 two unit files 1 foo ppu This is the file describing the unit you just compiled 2 foo o This file contains the actual code of the unit This file will eventually end up in the executables Both files are needed if you plan to use the unit for some programs So don t delete them If you want to distribute the unit you must provide both the ppu and o file One is useless without the other Remark Under LINUX a unit source file must have a lowercase filename Since Pascal is case independent you can specify the names of units in the uses clause in either case To get a unique filename the Free Pascal compiler changes the name of the unit to all lowercase when looking for unit files The compiler produces lowercase files so your unit will be found even if your source file has uppercase letters in it Only when the compiler tries to recompile the unit it will not find your source because of the uppercase letters 15 3 6 CREATING AN EXECU
77. nnot take the address of an expression which has a far reference as a result The mem construct has a far reference as a result so the following code will produce this error var p pointer p mem a000 000 Error illegal call by reference parameters You are trying to pass a constant or an expression to a procedure that requires a var parameter Only variables can be passed as a var parameter Error EXPORT declared functions can t be called No longer in use Warning Possible illegal call of constructor or destructor doesn t match to this context No longer in use Note Inefficient code You construction seems dubious to the compiler Warning unreachable code You specified a loop which will never be executed Example while false do begin code end Error procedure call with stackframe ESP SP The compiler encountered a procedure or function call inside a procedure that uses a ESP SP stackframe Normally when a call is done the procedure needs a EBP stackframe Error Abstract methods can t be called directly You cannot call an abstract method directy instead you must call a overriding child method because an abstract method isn t implemented Fatal Internal Error in getfloatreg allocation failure An internal error oc curred in the compiler If you encounter such an error please contact the de velopers and try to provide an exact description of the circumstances in which the error occurs
78. numeration type which has assignments in it as in C like in the following Tenum a b e 5 you cannot use the Succ or Pred functions on them Error Can t read or write variables of this type You are trying to read or write a variable from or to a file of type text which doesn t support that Only integer types booleans reals pchars and strings can be read from written to a text file Error Type conflict between set elements There is at least one set element which is of the wrong type i e not of the set type Warning lo hi dword qword returns the upper lower word dword Free Pascal supports an overloaded version of 1o hi for longint dword int64 qword which returns the lower upper word dword of the argument TP always uses a 16 bit lo hi which returns always bits 0 7 for lo and the bits 8 15 for hi If you want the TP behavior you have to type cast the argument to word integer Error Integer or real expression expected The first argument to str must a real or integer type Error Wrong type in array constructor You are trying to use a type in an array constructor which is not allowed 71 C 5 SYMBOL HANDLING Error Incompatible type for arg no argl Got arg2 expected arg3 You are trying to pass an invalid type for the specified parameter Error Method variable and Procedure variable are not compatible You can t assign a method to a procedure variable or a procedure to a method pointer Error Il
79. of course assuming that you installed under C PP or usr lib fpc 0 99 7 respectively If you got no error messages the compiler has generated an executable called hello no extension under LINUX and a file hello exe under Dos To execute the program simply type hello If all went well you should see the following friendly greeting Hello world In the DOS case this friendly greeting may be preceded by some ugly message from the GO32 extender program This unfriendly behavior can be switched off by setting the GO32 environment variable 11 Chapter 3 Compiler usage Here we describe the essentials to compile a program and a unit We also describe how to make a stand alone executable of the compiled program under Dos For more advanced uses of the compiler see the section on configuring the compiler and the Programmers guide The examples in this section suppose that you have a ppc386 cfg which is set up correctly and which contains at least the path setting for the RTL units In principle this file is generated by the installation program You may have to check that it is in the correct place see section for more information on this 3 1 File searching Before you start compiling a program or a series of units it is important to know where the compiler looks for its source files and other files In this section we discuss this and we indicate how to influence this Remark The use of slashes and backslashes
80. ogram property protected public raise record repeat self set shl shr stdcall string then to true try type unit until uses var virtual while with xor Appendix C Compiler messages This appendix is meant to list all the compiler messages The list of messages is generated from he compiler source itself and should be faitly complete At this point only assembler errors are not in the list C 1 General compiler messages This section gives the compiler messages which are not fatal but which display useful information The number of such messages can be controlled with the various verbosity level v switches Compiler argl When the vt switch is used this line tells you what compiler is used Compiler OS argl When the vd switch is used this line tells you what the source operating system is Info Target OS arg1 When the vd switch is used this line tells you what the target operating system is Using executable path arg1 When the vt switch is used this line tells you where the compiler looks for it s binaries Using unit path argl When the vt switch is used this line tells you where the compiler looks for compiled units You can set this path with the Fu Using include path arg1 When the vt switch is used this line tells you where the compiler looks for it s include files files used in I xxx statements You can set this path with the I option Using library path arg1 When
81. ome specific options when compiling some unit or program First we list the command line options and then we explain how to specify the command line options in the configuration file When reading this keep in mind that the options are case sensitive While this is customary for LINUX it isn t under DOS 5 1 Using the command line options The available options for version 0 99 10 of the compiler are listed by category see appendix A for a listing as generated by the compiler General options h if you specify this option the compiler outputs a list of all options and exits after that idem as h waiting after every screenfull for the enter key i This option tells the compiler to print the copyright information You can give it an option as ixxx where xxx can be one of the following D Returns the compiler date V Returns the compiler version SO Returns the compiler OS SP Returns the compiler processor TO Returns the target OS TP Returns the target Processor 19 5 1 USING THE COMMAND LINE OPTIONS l This option tells the compiler to print the Free Pascal logo on standard output It also gives you the Free Pascal version number n Tells the compiler not to read default the configuration file You can still pass a configuration file with the option Options for getting feedback vxxx Be verbose xxx is a combination of the following e e Tells the compiler to show only errors This op
82. ommand ppumove o both e ppl ppu ppu timer ppu under linux will generate the following output 35 7 1 SUPPLIED PROGRAMS PPU Mover Version 0 99 7 Copyright c 1998 by the Free Pascal Development Team Processing ppu ppu Done Processing timer ppu Done Linking timer o ppu o Done And it will produce the following files 1 libboth so The shared library containing the code from ppu o and timer o Under WINDOWS NT this file would be called both dll 2 timer ppl The unit file that tells the Free Pascal compiler to look for the timer code in the library 3 ppu ppl The unit file that tells the Free Pascal compiler to look for the timer code in the library You could then use or distribute the files libboth so Omer pp and ppu ppl ptop Pascal source beautifier ptop program ptop is a source beautifier written by Peter Grogono based on the ancient pretty printer by Ledgard Hueras and Singer modernized by the Free Pascal team ob jects streams configurability etc This configurability and the thorough bottom up design are the advantages of this program over the diverse TurboPascal sourcebeautifiers on e g SIMTEL The program is quite simple to operate ptop v i indent b bufsize c optsfile infile outfile The Infile parameter is the pascal file to be processed and will be written to outfile overwriting an existing outfile if it exists Some options modify the behaviour
83. ompiler can be compiled with or without support for a particular assembler reader Error Procedure directive argl has conflicts with other directives You spec ified a procedure directive that conflicts with other directives for instance cdecl and pascal are mutually exclusive Error Calling convention doesn t match forward This error happens when you declare a function or procedure with e g cdecl but omit this directive in the implementation or vice versa The calling convention is part of the function declaration and must be repeated in the function definition Error Register calling fastcall not supported The register calling con vention i e arguments are passed in registers instead of on the stack is not supported Arguments are always passed on the stack 68 C 3 PARSER MESSAGES Error Property can t have a default value Set properties or indexed proper ties cannot have a default value Error The default value of a property must be constant The value of a default declared property must be knwon at compile time The value you specified is only known at run time This happens e g if you specify a variable name as a default value Error Symbol can t be published can be only a class Only class type vari ables can be in a published section of a class if they are not declared as a property Error That kind of property can t be published Properties in a published section cannot be array properties the
84. on in paths To avoid having to edit your configuration files too often the compiler allows you to specify the following variables in the paths that you feed to the compiler FPCVER is replaced by the compiler s full version string FPCDATE is replaced by the compiler s date FPCTARGET is replaced by the compiler s target CPU deprecated FPCCPU is also replaced by the compiler s target CPU TARGET is replaced by the compiler s target OS deprecated FPCOS is replaced by the compiler s target OS To have these variables subsituted just insert them with a prepended as follows Fu usr lib fpc FPCVER rt1 FPCOS This is equivalent to Fu usr lib fpc 0 99 12a rt1 linux If the compiler version is 0 99 12a and the target os is linux These replacemens are valid on the command line and also in the configuration file On the linux command line you must be careful to escape the since otherwise the shell will expand the variable for you which may have undesired effects 28 Chapter 6 Porting Turbo Pascal Code Free Pascal was designed to resemble Turbo Pascal as closely as possible There are of course restrictions Some of these are due to the fact that Free Pascal is a 32 bit compiler Other restrictions result from the fact that Free Pascal works on more than one operating system In general we can say that if you keep your program code close to ANSI Pascal you will have no problems porting from Turbo Pascal
85. or even Delphi to Free Pascal To a large extent the constructs defined by Turbo Pascal are supported This is even more so if you use the So or S2 switches In the following sections we will list the Turbo Pascal constructs which are not supported in Free Pascal and we will list in what ways Free Pascal extends the Turbo Pascal language 6 1 Things that will not work Here we give a list of things which are defined allowed in Turbo Pascal but which are not supported by Free Pascal Where possible we indicate the reason 1 Parameter lists of previously defined functions and procedures must match exactly The reason for this is the function overloading mechanism of Free Pascal however the So switch solves this See 2 as comment delimiters are not allowed in versions older than 0 9 1 This can easily be remedied with a grown up editor 3 The MEM MEMW MEML and PORT variables for memory and port access are not available in the system unit This is due to the operating system Under Dos the extender unit GO32 PPU implements the mem constuct under LINUX the ports unit implements such a construct 4 PROTECTED PUBLIC PUBLISHED TRY FINALLY EXCEPT RAISE are reserved words This means you cannot create procedures or variables with the same name While they are not reserved words in Turbo Pascal they are in Delphi Using the So switch will solve this problem if you want to compile Turbo Pascal code that uses the
86. ormation about configuration This step is optional If you don t set this a default configuration is used 6 Set the Indent variable This is the number of spaces to use when indenting Tab characters are not used in the program This step is optional The indent variable is initialized to 2 7 Call PrettyPrint This will pretty print the source in Ins and write the result to OutS The function returns True if no errors occurred False otherwise So a minimal procedure would be Procedure CleanUpCode var Ins OutS PBufStream PPRinter TPrettyPrinter begin Ins New PBufStream Init ugly pp StopenRead TheBufSize OutS New PBufStream Init beauty pp StCreate TheBufSize PPrinter Create PPrinter Ins Ins 39 7 2 SUPPLIED UNITS PPrinter outS O0uts PPrinter PrettyPrint end Using memory streams allows very fast formatting of code and is perfectly suitable for editors 7 2 Supplied units Here we list the units that come with the Free Pascal distribution Since there is a difference in the supplied units per operating system we list them separately per system They are documented in the Unit reference Under DOS strings This unit provides basic string handling routines for the pchar type compa rable to similar routines in standard C libraries objects This unit provides basic routines for handling objects dos This unit provides basic routines for accessing the operatin
87. ou can set the verbosity level using the Vxxx option Here xxx is a combination of the following letters h show header info i show interface information m show implementation information d show only interface definitions show only interface symbols Se 7 show browser info a show everything default if no V option is present Demo programs Also distributed with Free Pascal comes a series of demonstration programs These programs have no other purpose than demonstrating the capabilities of Free Pascal They are located in the demo directory of the sources 34 7 1 SUPPLIED PROGRAMS Documentation Example programs All example programs of the documentation are available Check out the directories that end on ex in the documentation sources There you will find all example sources ppumove program ppumove is a program to make shared or static libraries from multiple units It can be compared with the tpumove program that comes with Turbo Pascal It should be distributed in binary form along with the compiler It s usage is very simple ppumove options unit1 ppu unit2 ppu unitn ppu Where options is a combination of b If specified ppumve will generate a batch file that will contain the external linking and archiving commands that must be executed The name of this batch file is pmove sh on LINUX and pmove bat otherwise d xxx If specified the output files will put in the direc
88. pe line followed by an empty line as follows Writeln Content type text html Writeln start output of the form And that s all there is to it 50 9 3 PM UNDER WINDOWS WHAT NOW 9 3 I m under Windows what now Under Windows the system of writing CGI scripts can be totally different If you use Free Pascal under Windows then you also should be able to do CGI programming but the above instructions may not work They are known to work for the xitami server however If some kind soul is willing to write a section on CGI programming under Windows for other servers I d be willing to include it here 51 Appendix A Alphabetical listing of command line options The following is alphabetical listing of all command line options as generated by the compiler ppc386 options lt inputfile gt options put after a boolean switch option to enable it to disable it the compiler doesn t delete the generated assembler file wc d lt x gt e lt x gt F lt x gt al ar at list sourcecode lines in assembler file list register allocation release info in assembler file list temp allocation release info in assembler file generate browser info b1 generate local symbol info build all modules code generation options CD Ch lt n gt Ci Cn Co Cr Cs lt n gt Ct CS Cx defines the set path to same as Cn create dynamic library lt n gt by
89. pper ptop is still development software so it is wise to visually check the generated source and try to compile it to see if ptop hasn t made any errors 38 7 1 SUPPLIED PROGRAMS ptopu unit The source of the PtoP program is conveniently split in two files One is a unit containing an object that does the actual beautifying of the source the other is a shell built around this object so it can be used from the command line This design makes it possible to include the object in some program e g an IDE and use it s features to format code The object resided in the PtoPU unit and is declared as follows TPrettyPrinter 0bject TObject Indent Integer How many characters to indent Ins PStream Outs PStream DiagS PStream CfgS PStream Constructor Create Function PrettyPrint Boolean end Using this object is very simple The procedure is as follows 1 Create the object using it s constructor 2 Set the Ins stream This is an open stream from which pascal source will be read This is a mandatory step 3 Set the OutS stream This is an open stream to which the beautified pascal source will be written This is a mandatory step 4 Set the DiagS stream Any diagnostics will be written to this stream This step is optional If you don t set this no diagnostics are written 5 Set the Cfgs stream A configuration is read from this stream see the previ ous section for more inf
90. r time try to generate faster code default r keep certain variables in registers experimental use with caution u Uncertain optimizations 1 Level 1 optimizations quick optimizations 2 Level 2 optimizations 01 plus some slower optimizations 3 Level 3 optimizations 02 plus 0u Pn Intel only Specify processor n can be one of 1 optimize for 386 486 2 optimize for Pentium PentiumMMX tm 3 optimizations for PentiumPro PII Cyrix 6x86 K6 tm The exact effect of these effects can be found in the Programmers guide 22 5 1 USING THE COMMAND LINE OPTIONS oxxx Tells the compiler to use xxx as the name of the output file executable Only with programs pg Generate profiler code for gprof s Tells the compiler not to call the assembler and linker Instead the compiler writes a script PPAS BAT under DOS or ppas sh under LINUX which can then be executed to produce an executable This can be used to speed up the compiling process or to debug the compiler s output Txxx Specifies the target operating system xxx can be one of the following e GO32V1 DOS and version 1 of the DJ DELORIE extender no longer maintained GO32V2 DOs and version 2 of the DJ DELORIE extender LINUX LINUX OS2 OS 2 2 x using the EMX extender WIN32 Windows 32 bit uxxx undefine the symbol xxx This is the opposite of the d option uxxx Undefine symbol xxx Xx executable options This tells the compiler what k
91. ramming While CGI programming can be done with almost any tool you wish most languages aren t designed for it Perl may be a notable exception but perl is an interpreted language the executable is quite big and hence puts a big load on the server machine Because of its simple almost intuitive string handling and its easy syntax Pascal is very well suited for CGI programming Pascal allows you to quickly produce some results while giving you all the tools you need for more complex programming The basic RTL routines in principle are enough to get the job done but you can create with relatively little effort some units which can be used as a base for more complex CGI programming That s why in this chapter we will discuss the basics of CGI in Free Pascal In the subsequent we will assume that the server for which the programs are created are based upon the NCSA httpd WWW server as the examples will be based upon the NCSA method of CGI programming They have been tested with the apache server on LINUX and the xitami server on WINDOWS NT The two example programs in this chapter have been tested on the command line and worked under the condition that no spaces were present in the name and value pairs provided to them There is however a faster and generally better uncgi unit available you can find it on the contributed units page of the Free Pascal web site It uses techniques discussed here but in a generally more efficient
92. rective If you don t specify the override directive you will hide the parent method you will not override it Error There is no method in an ancestor class to be overridden argl You try to override a virtual method of a parent class that doesn t exist Error No member is provided to access property You specified no read di rective for a property Warning Stored prorperty directive is not yet implemented The stored directive is not yet implemented Error Illegal symbol for property access There is an error in the read or write directives for an array property When you declare an array property you can only access it with procedures and functions The following code woud cause such an error tmyobject class i integer property x i integer integer read I write i Error Cannot access a protected field of an object here Fields that are de clared in a protected section of an object or class declaration cannot be ac cessed outside the module wher the object is defined or outside descendent object methods Error Cannot access a private field of an object here Fields that are de clared in a private section of an object or class declaration cannot be accessed outside the module where the class is defined Warning overloaded method of virtual method should be virtual arg1 If you declare overloaded methods in a class then they should either all be virtual or none You shouldn t mix them Warning overloaded met
93. ror Abstract methods shouldn t have any definition with function body Abstract methods can only be declared you cannot implement them They should be overridden by a descendant class Error This overloaded function can t be local must be exported You are defining a overloaded function in the implementation part of a unit but there is no corresponding declaration in the interface part of the unit Warning Virtual methods are used without a constructor in arg1 If you declare objects or classes that contain virtual methods you need to have a con structor and destructor to initialize them The compiler encountered an object or class with virtual methods that doesn t have a constructor destructor pair Macro defined argl When vm is used the compiler tells you when it defines macros Macro undefined arg1 When vm is used the compiler tells you when it unde fines macros Macro argl set to arg2 When vm is used the compiler tells you what values macros get Info Compiling arg1 When you turn on information messages vi the com piler tells you what units it is recompiling Compiling arg1 for the second time When you request debug messages vd the compiler tells you what units it recompiles for the second time Error Array properties aren t allowed at this point You cannot use array properties at that point a Error No property found to override You want to overrride a property of a parent class when there is i
94. ror Illegal use of 7 You are using the format colon 2 times on an ex pression that is not a real expression Error range check error in set constructor or duplicate set element The declaration of a set contains an error Either one of the elements is outside the range of the set type either two of the elements are in fact the same Error Pointer to object expected You specified an illegal type in a New state ment The extended synax of New needs an object as a parameter Error Expression must be constructor call When using the extended syntax of new you must specify the constructor method of the object you are trying to create The procedure you specified is not a constructor Error Expression must be destructor call When using the extended syntax of dispose you must specify the destructor method of the object you are trying to dispose of The procedure you specified is not a destructor Error Illegal order of record elements When declaring a constant record you specified the fields in the wrong order Error Expression type must be class or record type A with statement needs an argument that is of the type record or class You are using with on an expression that is not of this type Error Procedures can t return a value In Free Pascal you can specify a re turn value for a function when using the exit statement This error occurs when you try to do this with a procedure Procedures cannot return a value Error const
95. ror class type expected The variable of expression isn t of the type class This happens typically when 1 The parent class in a class declaration isn t a class 2 An exception handler On contains a type identifier that isn t a class Error Variable or type indentifier expected The argument to the High or Low function is not a variable nor a type identifier Error Can t evaluate constant expression No longer in use Error Set elements are not compatible You are trying to make an operation on two sets when the set element types are not the same The base type of a set must be the same when taking the union Error Operation not implemented for sets several binary operations are not defined for sets like div mod also j for now Warning Automatic type conversion from floating type to COMP which is an integer type An implicit type conversion from a real type to a comp is encountered Since Comp is a 64 bit integer type this may indicate an error Hint use DIV instead to get an integer result When hints are on then an integer division with the operator will procuce this message because the result will then be of type real Error string types doesn t match because of argV mode When compil ing in V mode the string you pass as a parameter should be of the exact same type as the declared parameter of the procedure Error succ or pred on enums with assignments not possible When you de clared an e
96. ructors and destructors must be methods You re declaring a pro cedure as destructor or constructor when the procedure isn t a class method Error Operator is not overloaded You re trying to use an overloaded operator when it isn t overloaded for this type Error Re raise isn t possible there You are trying to raise an exception where it isn t allowed You can only raise exceptions in an except block Error The extended syntax of new or dispose isn t allowed for a class You cannot generate an instance of a class with the extended syntax of new The constructor must be used for that For the same reason you cannot call Dispose to de allocate an instance of a class the destructor must be used for that 65 C 3 PARSER MESSAGES Error Assembler incompatible with function return type You re trying to implement a assembler function but the return type of the function doesn t allow that Error Procedure overloading is switched off When using the So switch pro cedure overloading is switched off Turbo Pascal does not support function overloading Error It is not possible to overload this operator overload instead You are trying to overload an operator which cannot be overloaded The fol lowing operators can be overloaded T I ER gt lt lt gt is as in k Error Comparative operator must return a boolean value When overload ing the operator the function must return a boolean
97. ry 2 In your home directory it looks for ppc386 cfg 3 The directory specified in the environment variable PPC_CONFIG_PATH and if it s not set under etc e Under all other OSes 1 The current directory 2 Ifit is set the directory specified in the environment variable PPC_CONFIG_PATH 3 The directory where the compiler is When the compiler has finished reading the configuration file it continues to treat the command line options One of the command line options allows you to specify a second configuration file Specifying foo on the command line will open file foo and read further options 24 5 2 USING THE CONFIGURATION FILE from there When the compiler has finished reading this file it continues to process the command line The configuration file allows some kind of preprocessing It understands the follow ing directives which you should place on the first column of a line IFDEF IFNDEF ELSE ENDIF DEFINE UNDEF WRITE INCLUDE SECTION They work the same way as their counterparts in Pascal What follows is a description of the different directives IFDEF Syntax IFDEF name Lines following IFDEF are skipped read if the keyword name following it is not defined They are read until the keywords ELSE or ENDIF are encountered after which normal processing is resumed Example IFDEF VERO_99_5 Up usr lib fpc 0 99 5 linuxunits ENDIF In the above example u
98. rying to add another element objects unit 216 General Protection fault You are trying to access memory outside your appointed memory 217 Unhandled exception occurred An exception occurred and there was no exception handler present The sysutils unit installs a default exception han dler which catches all excpetions and exits gracefully 227 Assertion failed error An assertion failed and no AssertErrorProc proce dural variable was installed 87 Appendix E The Floating Point Coprocessor emulator In this appendix we note some caveats when using the floating point emulator on GO32V2 systems Under GO32V1 systems all is as described in the installation section Q I don t have an 80887 How do I compile and run floating point programs under GO82V2 Q What shall I install on a target machine which lacks hardware floating point support A Programs which use floating point computations and could be run on machines without an 80387 should be allowed to dynamically load the emu387 dxe file at run time if needed To do this you must link the emu387 unit to your exectuable program for example Program MyFloat Uses emu387 var r real Begin r 1 0 WriteLn r end Emu387 takes care of loading the dynamic emulation point library You should always add emulation when you distribute floating point programs A few users reported that the emulation won t work for them unless they explicitly tell DJGPP there is no x
99. s can be achieved program cgi_post uses dos const max_data 1000 type datarec record name value string end var data array 1 max_data of datarec i nrdata longint c char literal aname boolean begin writeln Content type text html writeln if getenv REQUEST_METHOD lt gt POST then begin writeln This script should be referenced with a METHOD of POST write If you don t understand this see this write lt A HREF http www ncsa uiuc edu SDG Softare Mosaic writeln Docs fill out forms overview html gt forms overview lt A gt halt 1 end if getenv CONTENT_TYPE lt gt application x www form urlencoded then begin writeln This script can only be used to decode form results halt 1 end nrdata 1 aname true while not eof input do 47 9 1 GETTING YOUR DATA begin literal false read c if c then begin literal true read c end if literal or c lt gt and c lt gt amp then with data nrdata do if aname then name namet c else value valuetc else begin if c amp then begin inc nrdata aname true end else aname false end end writeln lt Hi gt Form Results lt H1 gt writeln You submitted the following name value pairs writeln lt UL gt for i 1 to nrdata do writeln lt LI gt data i name
100. s error when you tried to do an operation on a file which doesn t exist or when you try to change to or remove a directory that doesn t exist or try to make a subdirectory of a subdirectory that doesn t exist 4 Too many open files When attempting to open a file for reading or writing you can get this error when your program has too many open files 5 File access denied You don t have access to the specified file 6 Invalid file handle If this happens the file variable you are using is trashed it indicates that your memory is corrupted 12 Invalid file access code This will happen if you do a reset or rewrite of a file when FileMode is invalid 15 Invalid drive number The number given to the Getdir function specifies a non existent disk 16 Cannot remove current directory You get this if you try to remove the current diirectory 17 Cannot rename across drives You cannot rename a file such that it would end up on another disk or partition 100 Disk read error Dos only An error occurred when reading from disk Typ ically when you try to read past the end of a file 101 Disk write error DOS only Reported when the disk is full and you re trying to write to it 102 File not assigned This is reported by Reset Rewrite Append Rename and Erase if you call them with an unassigne function as a parameter 1The LINUX port will generate only a subset of these 85 103 File not open Reported by the following fun
101. s file Warning Procedure type FAR ignored This is a warning FAR is a construct for 8 or 16 bit programs Since the compile generates 32 bit programs it ignores this directive Warning Procedure type NEAR ignored This is a warning NEAR is a con struct for 8 or 16 bit programs Since the compile generates 32 bit programs it ignores this directive Warning Procedure type REGISTER ignored This is a warning REGISTER is ignored by FPC programs for now This is introduced first for Delphi compatibility Error No DLL File specified No longer in use Error Duplicate exported function name arg1 Exported function names in side a specific DLL must all be different Error Duplicate exported function index arg1 Exported function names in side a specific DLL must all be different Error Invalid index for exported function DLL function index must be in the range 1 FFFF Error Constructor name must be INIT You are declaring a constructor with a name which isn t init and the Ss switch is in effect See the Ss switch See 5 1 Error Destructor name must be DONE You are declaring a constructor with a name which isn t done and the Ss switch is in effect See the Ss switch See bi Error Illegal open parameter You are trying to use the wrong type for an open parameter Error Procedure type INLINE not supported You tried to compile a pro gram with C style inlining and forgot to specify the Si option ech The co
102. se words 5 The reserved words FAR NEAR are ignored This is because Free Pascal is a 32 bit compiler so they re obsolete 29 6 2 THINGS WHICH ARE EXTRA 6 INTERRUPT only will work on a DOS machine 7 Boolean expressions are only evaluated until their result is completely deter mined The rest of the expression will be ignored 8 By default the compiler uses AT amp T assembler syntax This is mainly because Free Pascal uses GNU as However other assembler forms are available grammers guide 9 Turbo Vision is not available 10 The overlay unit is not available It also isn t necessary since Free Pascal is a 32 bit compiler so program size shouldn t be a point 11 There are more reserved words see appendix D for a list of all reserved words 12 The command line parameters of the compiler are different 13 Compiler switches and directives are mostly the same but some extra exist 14 Units are not binary compatible 6 2 Things which are extra Here we give a list of things which are possible in Free Pascal but which didn t exist in Turbo Pascal or Delphi 1 There are more reserved words see appendix for a list of all reserved words 2 Functions can also return complex types such as records and arrays 3 You can handle function results in the function itself as a variable Example function a longint begin a 12 while a gt 4 do begin end end The examp
103. self Recompiling unit obj and asm are older than ppufile When you use the vu flag the compiler warns if the assembler of object file of the unit are older than the unit file itself Recompiling unit obj is older than asm When you use the vu flag the com piler warns if the assembler file of the unit is older than the object file of the unit Parsing interface of arg1 When you use the vu flag the compiler warns that it starts parsing the interface part of the unit Parsing implementation of arg1 When you use the vu flag the compiler warns that it starts parsing the implementation part of the unit Second load for unit arg1 When you use the vu flag the compiler warns that it starts recompiling a unit for the second time This can happend with interdepend units PPU Check file arg1 time arg2 When you use the vu flag the compiler show the filename and date and time of the file which a recompile depends on C 8 Command line handling errors This section lists errors that occur when the compiler is processing the command line or handling the configuration files Warning Only one source file supported You can specify only one source file on the command line The first one will be compiled others will be ignored This may indicate that you forgot a sign Warning DEF file can be created only for OS 2 This option can only be specified when you re compiling for OS 2 Error nested response files are not supported you c
104. sing opcode Invalid real constant expression Parenthesis are not allowed Invalid Reference Cannot use _SELF outside a method Cannot use _OLDEBP outside a nested procedure Invalid segment override expression Strings not allowed as constants Switching sections is not allowed in an assembler block 83 C 9 ASSEMBLER READER ERRORS Invalid global definition Line separator expected Invalid local common definition Invalid global common definition assembler code not returned to text invalid opcode size Invalid character Invalid character 3 Unsupported opcode Invalid suffix for intel assembler Extended not supported in this mode Comp not supported in this mode Invalid Operand Override operator not supported m68k specific errors Increment and Decrement mode not allowed together You are trying to use dec inc mode together Invalid Register list in movem fmovem The register list is invalid normally a range of registers should be separated by and individual registers should be separated by a slash Invalid Register list for opcode 68020 mode required to assemble 84 Appendix D Run time errors The Free Pascal Run time library generates the following errors at run time f 1 Invalid function number You tried to call a DOS function which doesn t exist 2 File not found You can get this error when you tried to do an operation on a file which doesn t exist 3 Path not found You can get thi
105. specified There is an error in the pa rameter list of the function or procedure the number of parameters is not correct Error overloaded identifier arg1 isn t a function The compiler encountered a symbol with the same name as an overloaded function but it isn t a function it can overload Error overloaded functions have the same parameter list You re declaring overloaded functions but with the same parameter list Overloaded function must have at least 1 different parameter in their declaration Error function header doesn t match the forward declaration arg1 You de clared a function with same parameters but different result type or function specifiers Error function header arg1 doesn t match forward var name changes arg2 j arg3 You declared the function in the interface part or with the forward direc tive but define it with a different parameter list Note Values in enumeration types have to be ascending Free Pascal allows enumeration constructions as in C Given the following declaration two dec larations 61 C 3 PARSER MESSAGES 6 A_UAS 200 6 A_UAS 4 3 3 type a type a A_A A_B A_E A_A A_B A_E The second declaration would produce an error A_UAS needs to have a value higher than A_E i e at least 7 Note Interface and implementation names are different argl arg2 This note warns you if the implementation and interface names of a functions are different but they hav
106. sr lib fpc 0 99 5 linuxunits will be added to the path if you re compiling with version 0 99 5 of the compiler IFNDEF Syntax IFNDEF name Lines following IFDEF are skipped read if the keyword name following it is defined They are read until the keywords ELSE or ENDIF are encountered after which normal processing is resumed Example 25 5 2 USING THE CONFIGURATION FILE IFNDEF VERO_99_5 Up usr lib fpc 0 99 6 linuxunits ENDIF In the above example usr lib fpc 0 99 6 linuxunits will be added to the path if you re NOT compiling with version 0 99 5 of the compiler ELSE Syntax ELSE ELSE can be specified after a IFDEF or IFNDEF directive as an alternative Lines following ELSE are skipped read if the preceding IFDEF IFNDEF was accepted They are skipped until the keyword ENDIF is encountered after which normal processing is resumed Example IFDEF VERO_99_5 Up usr lib fpc 0 99 6 linuxunits ELSE Up usr lib fpc 0 99 5 linuxunits ENDIF In the above example usr lib fpc 0 99 5 linuxunits will be added to the path if you re compiling with version 0 99 5 of the compiler otherwise usr lib fpc 0 99 6 linuxunits will be added to the path ENDIF Syntax ENDIF ENDIF marks the end of a block that started with IF N DEF possibly with an ELSE between it DEFINE Syntax DEFINE name DEFINE defines a new keyword This has the same effect as a dname command line option
107. tes heap between 1023 and 67107840 I0 checking omit linking stage check overflow of integer operations range checking set stack size to lt n gt stack checking create static library use smartlinking symbol lt x gt executable set file names and paths FD lt x gt Fe lt x gt FE lt x gt Fi lt x gt Fl lt x gt Fo lt x gt Fr lt x gt Fu lt x gt FU lt x gt sets the directory where to search for compiler utilities redirect error output to lt x gt set exe unit output path to lt x gt adds lt x gt to include path adds lt x gt to library path adds lt x gt to object path load error message file lt x gt adds lt x gt to unit path set unit output path to lt x gt overrides FE 52 g lt x gt generate debugger information gg use gsym gd use dbx gh use heap trace unit i information iD return compiler date iV return compiler version iS0 return compiler 0S iSP return compiler processor iT0 return target 0S iTP return target processor I lt x gt adds lt x gt to include path k lt x gt Pass lt x gt to the linker St write logo n don t read the default config file o lt x gt change the name of the executable produced to cz pg generate profile code for gprof S lt x gt syntax options S2 switch some Delphi 2 extensions on Sc supports operators like C and Sd tries to be Delphi compatible Se compiler stops after the first error Sg allow LABEL an
108. the vt switch is used this line tells you where the compiler looks for the libraries You can set this path with the F1 option Using object path arg1 When the vt switch is used this line tells you where the compiler looks for object files you link in files used in L xxx state ments You can set this path with the Fo option Info arg1 Lines compiled arg2 sec When the vi switch is used the compiler reports the number of lines compiled and the time it took to compile them real time not program time 56 C 2 SCANNER MESSAGES Fatal No memory left The compiler doesn t have enough memory to compile your program There are several remedies for this e If you re using the build option of the compiler try compiling the different units manually e If you re compiling a huge program split it up in units and compile these separately e If the previous two don t work recompile the compiler with a bigger heap you can use the Ch option for this Sec C 2 Scanner messages This section lists the messages that the scanner emits The scanner takes care of the lexical structure of the pascal file i e it tries to find reserved words strings etc It also takes care of directives and conditional compiling handling Fatal Unexpected end of file this typically happens in one of the following cases e The source file ends before the final end statement This happens mostly when the begin and end statements
109. the GNU profile 45 CONTENTS KI programming in ata coming ee Pascal rough standard input Data passed through an environment variab m under Windows what now A lphabetica Alpnapetica el isting of command line option 1st Oi reserved word ompiler message eneral compiler Messages canner messages 4 8 Parser messages pe checking error A o d ode generator messages Uni oading messages Re ommand line handling error LU Assembler reader errors 1580 Sp S mOSk sp l e Floating Point Coprocessor emulato ow 46 46 47 48 50 51 52 55 56 56 57 60 70 72 74 76 78 79 79 82 84 85 88 90 Chapter 1 Introduction 1 1 About this document This is the user s manual for Free Pascal It describes the installation and use of the Free Pascal compiler on the different supported platforms It does not attempt to give an exhaustive list of all supported commands nor a definition of the Pascal language Look at the for these things For a description of the possibilities and the inner workings of the compiler see the Programmers guide In the appendices of this document you will find lists of reserved words and compiler error messages with descriptions This document describes the compiler as it is functions at the time of writing Since the compiler is under continuous development some of the things described here
110. tion is on by default e i Tells the compiler to show some general information e w Tells the compiler to issue warnings e n Tells the compiler to issue notes e h Tells the compiler to issue hints e 1 Tells the compiler to show the line numbers as it processes a file Numbers are shown per 100 e u Tells the compiler to print the names of the files it opens e t Tells the compiler to print the names of the files it tries to open e p Tells the compiler to print the names of procedures and functions as it is processing them e c Tells the compiler to warn you when it processes a conditional e m Tells the compiler to write which macros are defined e d Tells the compiler to write other debugging info ea Tells the compiler to write all possible info this is the same as specifying all options e O Tells the compiler to write no messages This is useful when you want to override the default setting in the configuration file e b Tells the compiler to show all procedure declarations if an overloaded function error occurs e x Tells the compiler to output some executable info for Win32 platform only e x Rhide GCC compatibility mode formats the errors differently so they are understood by RHIDE Options concerning files and directories exxx xxx specifies the directory where the compiler can find the executables as the assembler and Id the compiler FD same as e Fexxx This option
111. tory xxx e xxx Sets the extension of the moved unit files to xxx By default this is pp You don t have to specify the dot o xxx sets the name of the output file i e the name of the file containing all the units This parameter is mandatory when you use multiple files On LINUX ppumove will prepend this name with lib if it isn t already there and will add an extension appropriate to the type of library q Causes ppumove to operate silently s Tells ppumove to make a static library instead of a dynamic one By default a dynamic library is made on LINUX w Tells ppumove that it is working under WINDOWS NT This will change the names of te linker and archiving program to Idw and arw respectively h or will display a short help The action of the ppumve program is as follows It takes each of the unit files and modifies it so that the compile will know that it should look for the unit code in the library The new unit files will have an extension ppu this can be changed with the e option It will then put together all the object files of the units into one library static or dynamic depending on the presence of the s option The name of this library must be set with the o option If needed the prefix lib will be prepended under LINUX The extension will be set to a for static libraries for shared libraries the extensions are so on linux and d11 under WINDOWS NT and os 2 As an example the following c
112. way and it also provides some extra functionality not discussed here 9 1 Getting your data Your CGI program must react on data the user has filled in on the form which your web server gave him The Web server takes the response on the form and feeds it to the CGI script There are essentially two ways of feeding the data to the CGI script We will discuss both 1 and it s the only WWW server I have to my disposition at the moment 46 9 1 GETTING YOUR DATA Data coming through standard input The first method of getting your data is through standard input This method is in voked when the form uses a form submission method of POST The web browser sets three environment variables REQUEST_METHOD CONTENT_TYPE and CONTENT_LENGTH It feeds then the results of the different fields through standard input to the CGI script All the Pascal program has to do is e Check the value of the REQUEST_METHOD environment variable The getenv function will retrieve this value this for you e Check the value of the CONTENT_TYPE environment variable e Read CONTENT_LENGTH characters from standard input read c with c of type char will take care of that if you know that the request method will always be POST and the CONTENT_TYPE will be correct then you can skip the first two steps The third step can be done easier read characters until you reach the end of file marker of standard input The following example shows how thi
113. y must be moved to public sections Properties in a published section must be an ordinal type a real type strings or sets Warning Empty import name specified Both index and name for the import are 0 or empty Warning Empty import name specified Some targets need a name for the imported procedure or a cdecl specifier Error Function internal name changed after use of function Error Division by zero There is a divsion by zero encounted Error Invalid floating point operation An operation on two real type values produced an overflow or a division by zero Error Upper bound of range is less than lower bound The upper bound of a case label is less than the lower bound and this is not possible Error string length is larger than array of char length The size of the con stant string is larger than the size you specified in the array x y of char definition Error Illegal expression after message directive Free Pascal supports only integer or string values as message constants Error Message handlers can take only one call by ref parameter A method declared with the message directive as message handler can take only one pa rameter which must be declared as call by reference Parameters are declared as call by reference using the var directive Error Duplicate message label arg1 A label for a message is used twice in one object class Error Self can be only an explicit parameter in message handlers The self parameter can be passed

Users` Guide

Contents

Download Pdf Manuals

Related Search

Related Contents