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Modula-2 Compiler (C) Copyright 1987 Fitted Software Tools. All rights reserved. Fitted Software Tools P.O.Box 956129 Duluth, Ga 30136 DISCLAIMER OF WARRANTY THIS SOFTWARE AND MANUAL ARE PROVIDED "AS IS" AND WITHOUT WARRANTIES AS TO PERFORMANCE OR MERCHANTABILITY. THIS SOFTWARE IS PROVIDED WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES WHATSOEVER. BECAUSE OF THE DIVERSITY OF CONDITIONS AND HARDWARE UNDER WHICH THIS SOFTWARE MAY BE USED, NO WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE IS OFFERED. THE USER IS ADVISED TO TEST THIS SOFTWARE THOROUGHLY BEFORE RELYING ON IT. THE USER MUST ASSUME THE ENTIRE RISK OF USING THIS SOFTWARE. IBM is a registered trademark of International Business Machines Corporation. - 1 - Chapter 1 Introduction Thank you for your interest in our Modula-2 compiler. This system features a Modula-2 compiler with an integrated editor and "make" facility, a program linker, a makefile generator, and an execution profiler. The compiler generates code for the Intel 8086 "huge" memory model: Each module has its own data and code segment, each of which can be up to 64k in size; pointers are four bytes long. More restrictive memory models are not currently supported. All the library and runtime support source code is provided to our registered users (see Shareware). We hope that our effort will prove itself worthy of your support. Introduction 2 1.1 Hardware requirements This system will run on IBM PC, PC/AT, or compatible systems with at least 512K of RAM, two double sided floppy disk drives and a monochrome display adapter, color graphics adapter or equivalent. For best performance, a hard disk and 640K of RAM are recommended. 1.2 Software requirements This system will run under DOS version 2.0 or later. No other software is required to use this system, but you will need an assembler if you intend to modify one of the runtime support modules: M2Reals (floating point support), M2Longs (LONG arithmetic) or M2Procs (coroutine handling). Introduction 3 Chapter 2 Software installation 2.1 Theory The library module Terminal requires that the ANSI.SYS driver be installed. The executable files (MC.EXE, M2LINK.EXE, ...) should, for ease of operation, be placed in a drive/directory named in the DOS PATH variable. The editor configuration file M2ED.CFG must be accessible through the DOS PATH variable. Both the compiler and the linker will use the environment variable M2LIB to locate required library modules (the format for the M2LIB entry matches that of the DOS PATH). The compiler and utilities in this package do not keep many files open simultaneously. If you set the FILES parameter in CONFIG.SYS to 10 you should not encounter any problems. For performance considerations, you should also allocate more than the default number of buffers for DOS: If you are running on a PC class machine, try allocating 20 buffers in your CONFIG.SYS. On an AT type machine, try 64 buffers. Example CONFIG.SYS: DEVICE=ANSI.SYS FILES=10 BUFFERS=20 This compiler is a memory hog (you heard it here first!). Therefore, unless you have 640k of memory installed in your system, you should have COMMAND.COM available for reload once you exit the compiler. If you have 640k of memory, you will probably want to enable the "COMMAND save" feature of the compiler, which will stop it from clobbering the resident portion of COMMAND.COM. Just add the following line to your AUTOEXEC.BAT file: SET CMDSIZE=NN where NN is the size of the resident portion of COMMAND.COM Software installation 4 in K (18 for DOS 3.0). MC clobbers the top of the memory space available for use during initialization. Therefore, to find out the size of the resident portion of COMMAND.COM try the following procedure: start by setting CMDSIZE to the size of COMMAND.COM. If now you execute MC, exit it, and press the F3 key, DOS will still remember your MC command. Decrement CMDSIZE and retry the MC test until the system forgets your last command (COMMAND.COM had to be reloaded). 2.2 Recommended setup for a system with 2 floppy drives This whole system is too large to fit in a single 360k floppy. Therefore, it is recommended that you build a "compiler" floppy and a "utilities" floppy (you may combine them both in a 720k or 1.2Mb floppy). On the compiler floppy, place the compiler (MC.EXE), all the library definition modules (*.DEF) and the file M2ED.CFG. The utilities floppy will take all the rest: the linker (M2LINK.EXE), other .EXE files, and the library and runtime support object files (*.M2O and *.BIN). Assuming that you will use drive A for the compiler and utilities disk and drive B as your work drive, add the following to your AUTOEXEC.BAT file: SET PATH=A: SET M2LIB=A: Software installation 5 2.3 Recommended setup for a hard disk system Place the executable files (*.EXE) and M2ED.CFG in a directory currently in the DOS search path, or in a new directory (ex: \MODULA2) to be added to the PATH list. Example: SET PATH=C:\BIN;C:\MODULA2 Make a directory for the library files (ex: \M2LIB) and copy all the .DEF, .M2O and .BIN files to it. To the AUTOEXEC.BAT file add the line: SET M2LIB=C:\M2LIB You will probably want to create a directory for your own reusable library modules. This directory can be added to the M2LIB environment variable. Example: SET M2LIB=C:\M2LIB;C:\MYLIB You may keep your projects in their own, individual, directories. Software installation 6 Chapter 3 A little tour through the system After you finish the installation as described above, you are left with a few .MOD files. These are the example programs. Please copy them to your work disk or directory. First, we will look at the unnatural case of compiling, linking and running a program that works the first time around. Please execute the following commands: MC SIEVE /C M2LINK SIEVE /O Well, that's it! Ready to run... SIEVE Now for the more usual case: MC BADSIEVE From the compiler menu, select 'C' for compile. Gee, that was quick! Press RETURN to take a look at our errors... The cursor is now positioned at the location of the first error. Using the keys Ctrl-E (find next error) and Ctrl-P (find previous error) you may visit all the errors flagged by the compiler. All the while, the editor shows the error description on the top line of the screen. But, going back to the first error... We really confused the compiler when we mistakenly typed in '.' instead of '..' in the range declaration. Move the cursor back (left arrow key) to where the '.' is, type in another '.', and that should fix that! As you will see as you type Ctrl-E, that single error caused the compiler to dislike a few other things on that same line; we will just ignore those errors and go on. Go on to the next error location (line 22). This time, we should have used a ']' but typed '}' instead. The backspace key will delete the offending character; now, type the ']' in its place. And that is that. Shall we try to compile the program A little tour through the system 7 again? Press Alt-S to save the file, Alt-Q to leave the editor and, back at the main menu, select 'C'. More errors?! These errors should have been detected during pass2 of the compiler; If not, you may try to fix these errors and recompile, or you may opt for loading and compiling the new file BADSIEV1.MOD, which contains the earlier fixes. Going back to the editor... We find that we used the identifier 'cnt' which is undefined; we really meant to use count. So, moving the cursor around with the cursor keys and/or deleting characters with the backspace or delete key, please replace 'cnt' by 'count'. Searching for the next error... The next error occured during the processing of the call to WriteCard. What happened here is that WriteCard requires 2 parameters, the second one being the size of the field to display. So, to fix it, let's insert a comma after 'count' and some number (for example 'count,4'). Any more erors? No, that is it... We now save the file (Alt-S), quit the editor (Alt-Q) and recompile (c). Now, the program should have compiled without errors. If not, you may recompile BADSIEV2.MOD instead. We may now quit the compiler (q). By now, we have some program that has compiled clean (BADSIEVE, BADSIEV1 or BADSIEV2). In what follows, we will assume all went well and we have BADSIEVE. If you look at the directory, you will see the new object module created as a result of the previous exercise (BADSIEVE.M2O). The compiler always writes its output to a file with the extension 'M2O'. Let us link and test the program: M2LINK BADSIEVE /L We use the /L option so that the line number information written out by the compiler to the object file will be preserved by the linker. We will need this information later. A little tour through the system 8 BADSIEVE A runtime error? And it gives us a PC location. Very informative, is it not? How in the world are we supposed to fix the program based on that? Do not dispair! Looking at your directory, you will notice that the linker created 2 files: BADSIEVE.EXE and BADSIEVE.DBG. No, TYPEing BADSIEVE.DBG does not help, it just displays garbage. But we have a utility called DBG2MAP that will convert the information in that file to a DOS LINK compatible MAP file. Let's try it: DBG2MAP BADSIEVE Now, using your favorite editor (or the editor in MC: MC BADSIEVE.MAP and then E), look at the contents of BADSIEVE.MAP. In the last few lines of the file, we have the line number information for BADSIEVE. If you look up the line whose address is closest (but lower) to the PC in the error message, you get the number of the line where the error occured (line 22). Let's see what happened... MC BADSIEVE Pick 'E' to go into the editor and, either move the cursor down to the line indicated by your research, or let the editor find it with Alt-G. So, what is the problem? Well, we declared the 'flag' array to have a maximum index of 8190, but 'j' got bigger than that (the FOR loop will increment 'j' up to the value of 10000). You may fix the problem by deleting the '10000' and typing in its place 'SIZE'. Recompile the program, link it, and run it. Did it work? Good. It is time for you to experiment on your own. But, before you do much more, you may want to check out the Editor chapter of the documentation. A little tour through the system 9 Chapter 4 The Compiler In Modula-2, identifiers may be used before they are declared, except when they are used in another declaration (this restriction does not apply to pointers). This forces the compilation process to be done in at least two passes. To avoid imposing unnecessary restrictions and, yet, provide reasonable performance, the two pass approach was selected: During the first pass, syntax analysis and declaration analysis are performed; The second pass performs the semantic analysis and code generation. The compiler has an integrated text editor. Should errors be encountered, the editor is invoked at the end of the current compiler pass (sooner, if an error is found during the processing of an import list or if 20 errors are identified). The compiler also has a built in "make" processor. A makefile must be created before this process is invoked. Although you can create a makefile using the editor, we recommend that you use the utility provided for that purpose: GENMAKE. The Compiler 10 4.1 Running the compiler Compiler invocation: MC [myprog] [/c] If the compiler is invoked without the '/c' option, you will get a screen that looks something like this: Modula-2 compiler, Version 1.0 (C) Copyright 1987 Fitted Software Tools. All rights reserved. Editor Heap in use: 18K Available Heap: 216K Work module: myprog.MOD New Compile Edit Make Quit > The options at this point are: New Specify another "Work module". Compile Compile the "Work module". Edit Edit the "Work module". Make Recompile all the necessary modules as per the rules of a makefile (you will be prompted for the makefile). Note: If errors are encountered during the compilation of one of the modules, the make process is aborted! Quit Return to DOS. If you use of the '/c' command line option, the compiler starts compiling "myprog" immediately and, if no errors are encountered, will bring you right back to the DOS prompt. This is useful when running the compiler from a batch file: MC myprog /c The compiler sets the DOS errorlevel to 0 if the last compile was successful (no errors); otherwise, the DOS errorlevel is set to 1. The Compiler 11 4.2 The compilation process 4.2.0.1 The input file If the module to be compiled is already loaded into one of the editor buffers, that source is compiled. Otherwise, the compiler tries to open the named file. 4.2.0.2 The imported modules The compiler and the linker cooperate in assuring that all the modules that refer to a particular definition module will have been compiled against the same version of that definition module. To this end, the compiler places in the 'module header' and 'module import' records of the object file a "module key". This module key is the date of the DEF file used during the compilation of the implementation module or during the processing of the IMPORT statement. Due to this, the compiler will not look in the editor buffers for the DEF files needed to process an IMPORT list. These are always read in from the disk. 4.2.0.3 The output file The output from the compilation of a main module or an implementation module is a single output file, with the same name of the source file but with the extension of 'M2O' (Modula-2 Object). The compilation of a definition module does not generate any new output files. If the compilation is successful (no errors), the compiler simply 'touches' the source file, updating its modification time. 4.2.0.4 A warning Because of the fact that the compiler uses the date of the The Compiler 12 DEF file as that module's key, you may not modify a DEF file unless you intend to recompile all the modules that use it, nor can you copy the file in such a way that its date is not preserved. In particular, if you are going to be transferring your modules between computers, you must use some procedure that will preserve all the DEF files' dates. 4.3 Compiler directives Certain compiler code generation options may be set through directives included in the program text. These directives must appear immediately at the beginning of a comment; multiple directives may be entered in a single comment by separating them by commas. Example (* $S-, $R+ *) A '+' sets the directive to TRUE, a '-' sets it to FALSE. The following compiler directives are defined: $A Alignment. Default $A+. If enabled, all new variables declared are aligned on a word boundary. Record fields are packed (not aligned) regardless of the setting of this option. $S Stack overflow checking. Default $S+. If enabled, stack overflow checking is performed on entry to a procedure and when copying open arrays to a procedure's local stack frame. $R Range checking. Default $R+. If enabled, before any assignment is made to a variable of a subrange type, the value to be assigned is tested against the limits of the subrange type. $T Array subscript checking. Default $T+. If enabled, any time a subscript operation is performed on an array, the subscript value is checked to confirm that the operation would not generate an address outside the bounds of the array. $L Generate line number information. Default $L-. If this option is enabled, the compiler will include a list of source code line numbers and their corresponding object code The Compiler 13 offsets in the output file. This line number information is passed on to the .DBG file when the program is linked with the /L option. 4.4 Runtime errors When, during the execution of a program, a runtime error is detected, the runtime error handler will terminate the program and write out a message indicating the type of error encountered and its location (PC address). To find the location of the error in the source code, run DBG2MAP against the .DBG file generated by M2LINK for this program. Scanning the .MAP file created, you should be able to always determine the module and procedure where the error occured. If the $L+ directive was used when compiling the module in question and the /L option was used when linking the program, the error location can be pinpointed to the offending line by scanning the line number information at the end of the .MAP file. 4.4.1 Trapping runtime errors in your program The Library module System provides you with a means of intercepting runtime errors. The following are the currently defined runtime error numbers that may be passed to your error handler routine: 0 stack overflow ($S option) 1 range error ($R or $T option) 2 integer/cardinal overflow (divide by zero) 3 floating point error 4 function did not execute a RETURN 5 HALT was invoked 4.5 Compiler size limits The following are the code and data size limits imposed by this compiler: - A string constant cannot exceed 80 characters. This is also the limit set for the size of any identifier. The Compiler 14 - Each compilation module is assigned its own data segment, which can be up to 64k in size. In the data segment, the compiler allocates the space for all the module's global variables and some of the module's constants. - The maximum size of a data structure is 65532 bytes. - The maximum amount of space allocated for variables local to a procedure is 32000 bytes. - The compiler will also refuse to generate the code to pass, in a procedure call, by value, a parameter greater than 65000 bytes in size. The following are the compiler's internal limits: - The maximum number of different (namewise) identifiers that can be processed in a single compilation is 2000. - The total number of characters in all the different (namewise) identifiers processed cannot exceed 8000 characters. - No single procedure can be translated into more than 10k of object code. - An array of 8k bytes is used to keep track of all the initialized data for a module. This imposes a limit on the total amount of string, real and long constants used in the compilation module. 4.6 The language supported This release of the compiler will translate a program written in the Modula-2 language as defined by Niklaus Wirth in the 3rd edition of his book "Programming in Modula-2", with the exceptions noted bellow: - Integer and Cardinal arithmetic overflow is not detected. - Module priority specifications are not allowed. - ASM is a reserved word in this implementation. - For those programmers that "grew up" in the Hex world, a way to define CHAR literals in Hex is provided: 20X corresponds to the "space" character in ASCII. The Compiler 15 4.6.1 LONGINT and LONGCARD This compiler implements the standard types LONGINT and LONGCARD. Operands of the type LONGINT or LONGCARD may appear in any expression, just like INTEGER or CARDINAL. But that is about it! Subranges of these types are not supported. No standard procedure (like INC, DEC) except the ones listed later in this document will accept operands of one of these types. A variable of type LONGINT or LONGCARD cannot be used as the control variable in a FOR loop. Neither can CASE labels be of a LONG type. Constants of type LONGINT or LONGCARD can be coded in decimal only and are terminated by an 'L'. Example 123L is a valid LONGCARD or LONGINT constant -348762L is a valid LONGINT constant 565656 -89076 are CARDINAL and INTEGER constants out of range 4.6.2 Additional standard procedures 4.6.2.1 NEW and DISPOSE NEW and DISPOSE have been deleted from the language definition in the 3rd edition of Wirth's book. We implement them thus: NEW(p) Invokes the procedure ALLOCATE, which must conform to the type: PROCEDURE ( VAR ADDRESS, CARDINAL ) passing along p and the size of the object p is defined as pointing to. DISPOSE(p) Invokes the procedure DEALLOCATE, which must conform to the type: PROCEDURE ( VAR ADDRESS, CARDINAL ) The Compiler 16 passing along p and the size of the object p is defined as pointing to. The procedures ALLOCATE and DISPOSE must, therefore, be defined in the module using NEW and/or DISPOSE, or imported from some other module, like Storage. 4.6.2.2 LONG and SHORT PROCEDURE LONG( INTEGER ) :LONGINT; PROCEDURE LONG( CARDINAL ) :LONGCARD; PROCEDURE SHORT( LONGINT ) :INTEGER; PROCEDURE SHORT( LONGCARD ) :CARDINAL; LONG takes an INTEGER (CARDINAL) and converts it into a LONGINT (LONGCARD). SHORT takes a LONGINT (LONGCARD) and converts it into an INTEGER (CARDINAL). 4.7 Objects exported by the pseudo module SYSTEM 4.7.0.1 TYPE BYTE Takes 1 byte of storage. Only assignment is defined for this type. If the formal parameter of a procedure is of type BYTE, the corresponding actual parameter may be of any type that takes 1 byte of storage. If the formal parameter of a procedure is of type ARRAY OF BYTE, the corresponding actual parameter may be of any type. 4.7.0.2 TYPE WORD Takes 1 word (2 bytes) of storage. Only assignment is defined for this type. If the formal parameter of a procedure is of type WORD, the corresponding actual parameter may be of any type that takes 1 word of storage. If the formal parameter of a procedure is of type ARRAY OF WORD, the corresponding actual parameter may be of any type. Care should be taken in this case, as the size of the parameter passed is rounded up to an even size. The Compiler 17 4.7.0.3 TYPE ADDRESS The type ADDRESS is compatible with all pointer types. ADDRESS itself is defined as a POINTER TO WORD. In this implementation, the type ADDRESS is not compatible with any arithmetic type. This is due to the fact that the Intel 8086 series processors use segmented addresses. It would not be hard to implement automatic conversions between LONGCARD and ADDRESS but it is felt that this would be contrary to the spirit of the language, whereby the compiler is not expected to perform any "magic" tricks. Instead, two functions are provided for that purpose: FLAT and PTR. 4.7.0.4 SEG and OFS These are field definitions for POINTER types. If you import these you may access the segment or offset portions of a pointer variable using regular field selection syntax. Example pointer.SEG :segment portion of pointer 4.7.0.5 PROCEDURE ADR ADR( designator ) Returns the address of designator (type ADDRESS). 4.7.0.6 PROCEDURE FLAT FLAT( ADDRESS ) returns a LONGCARD "flat" address. 4.7.0.7 PROCEDURE PTR PTR( LONGCARD ) returns an ADDRESS corresponding to the "flat" address represented by the LONGCARD. 4.7.0.8 PROCEDURE NEWPROCESS NEWPROCESS(p:PROC; a:ADDRESS; n:CARDINAL; VAR p1:ADDRESS) creates a new process whose entry point is p and workspace is at a for n bytes. p1 is the new process pointer. This process is not activated until a TRANSFER to p1 is done. 4.7.0.9 PROCEDURE TRANSFER TRANSFER( VAR p1, p2 :ADDRESS) suspends the current process, assigning it to p1 and resumes The Compiler 18 p2. The current process' value is assigned to p1 only after p2 has been identified; it is, therefore, okay for p1 and p2 to be the same. 4.7.0.10 PROCEDURE IOTRANSFER IOTRANSFER( VAR p1, p2 :ADDRESS; intVector :CARDINAL ) issues a TRANSFER from p1 to p2 (just the way TRANSFER does it) after installing the current process for reactivation when an interrupt comes in through interrupt vector intVector. When the interrupt occurs, the interrupt vector is reloaded with its previous value. A TRANSFER is done to the I/O process (the one that issued the IOTRANSFER) such that p2 now contains the value of the process that was running when the interrupt occured. 4.7.0.11 ASSEMBLER An 8086 inline assembler is provided. Once ASSEMBLER is imported from SYSTEM, you can enter inline assembler code by bracketing it with the keywords ASM and END. Assembler input is free form. Comments are entered as in regular Modula-2. Example loop: CMP BYTE [SI], 0 (*end of string?*) MOV BYTE [DI], [SI] INC SI INC DI (*increment pointers*) JMP loop The assembler accepts all the 8086/8088 opcode mnemonics. Address operands can be coded in just about any form acceptable to other assemblers, except that the only operator supported if '+'. Operand type overrides are: WORD, BYTE, FAR, NEAR and are not to be followed by the keyword POINTER or PTR. Example label: MOV AX, ES:[BX,DI+5] MOV AX, ES:5[DI+BX] MOV WORD [5], 1 CALL NEAR [DI] TEST BYTE i+2, 1 All the mnemonics and register names must be entered in upper case. In case you need to use a Modula-2 name that conflicts with one of the assembler reserved symbols, you may precede it with a '@'. Example MOV @AX, AX would generate a move from register AX to variable AX. The Compiler 19 All modula-2 variables can generaly be accessed in assembler. Record field names are not accessible from assembler. The assembler will not automatically do anything for you. For example: if you specify a VAR parameter as an operand to an instruction, you are naming the address of the pointer to the actual parameter. Example PROCEDURE p( VAR done :BOOLEAN ); ... ASM LES DI, done MOV BYTE ES:[DI], TRUE END; is the correct way of storing TRUE in done. The following types of constants may be accessed in assembler: INTEGER, CARDINAL, BOOLEAN, CHAR and enumeration constants. All labels declared inside an ASM section are local to that section of code. But labels names cannot match some name known in the scope of the current procedure. Labels can only be referenced in jump instructions. All jumps are optimized by the compiler. There is, therefore, no need (or capability) to specify the size of a jump. In particular, the compiler will turn a conditional jump out of range into a reverse conditional jump over a far jump to the original destination. Remember, this is a Modula-2 compiler, not an assembler! The inline assembler capability is provided for use in exceptional situations only. 4.8 The generated object code 4.8.1 Data type representation CHAR 1 byte INTEGER 2 bytes 2's complement CARDINAL 2 bytes LONGCARD 4 bytes LONGINT 4 bytes 2's complement The Compiler 20 BOOLEAN 1 byte (1=TRUE, 0=FALSE) REAL 4 bytes Intel 8087 format. BITSET 1 word. 0 is low order bit, 15 is high order bit. Enumerations 1 byte SETs 1 to 8 words (sets of up to 256 elements) POINTERs 4 bytes in Intel 8086/88 format PROCEDUREs 4 bytes POINTER to procedure entry point Addresses are represented in the default Intel 8086 format: 1 word byte offset 1 word segment Numeric values are likewise represented the way the Intel 8086 processor family likes them: low order byte first, high order byte last. 4.8.2 The runtime memory map Currently, the compiler generates code using the "huge" memory model only. Each module has its own data and code segments. The linker binds all the code segments first, and then all the data segments. The stack is allocated above the data segments. All the remainning memory is available for the heap. When a program is loaded for execution, here is what the memory looks like: From low to high addresses: 0 ---------------------------------------------- I Interrupt vectors I I DOS I PSP I Program segment prefix I PSP+100h I Program Code segments I I Program Data segments I StackSeg I Stack I HeapTop I Heap I I ... I I DOS Command (resident portion) I MemTop ---------------------------------------------- Label names on the left are the ones exported by System. The Compiler 21 This system uses interrupt vector 192 (0C0H) at location 0000:0300. Interrupt 192 is issued by a program when a runtime error occurs, when HALT is invoked or when a coroutine other than the main one terminates via a return. The first word (offset 0) in every code segment contains the data segment value for that particular module. 4.8.3 Procedure calling conventions Procedure parameters are pushed into the stack 1st argument first. Control is then transferred to the procedure through a FAR call. It is the called procedure's responsibility to remove its parameters from the stack before returning. 4.8.3.1 Parameter passing (all except open array parameters) If the formal parameter of a procedure is a value parameter, the actual parameter is copied into the stack. If the formal parameter is a variable parameter (VAR), the address of the actual parameter is pushed into the stack (first the segment portion of the address and then the offset part). 4.8.3.2 Parameter passing (open array parameters) If the formal parameter is an open array, the address and HIGH value of the corresponding formal parameter are pushed into the stack (HIGH value first, and then the address, as above). If the open array parameter is a value parameter, the value of the actual parameter is copied into the stack on procedure entry. The Compiler 22 Chapter 5 The Text Editor The text editor included in this package has all the features that you have come to expect from a basic program editor: the ability to insert, delete, move, find and replace text; support for concurrent editing of multiple files (as many as will fit in memory) in separate windows (as many as will fit on the screen) with the ability to copy or move text from window to window. Although you may load the same file in two different windows, the editor will not be aware of the fact and will treat the two copies as two different files. The only preset limitation in the editor is that it cannot handle files bigger than 64k. This decision was justified by the fact that Modula-2 programs are supposed to be modular. File load/save speed was the overriding factor here. All the text editor keys are defined by the user through the use of the EDCONFIG program. When the editor starts, it expects to find the file M2ED.CFG in the current PATH. To get you started, we provide a M2ED.CFG file with the following definitions: Cursor left : Left Cursor right : Right Cursor up : Up Cursor down : Down Previous word : ^Left Next word : ^Righ Page up : PgUp Page down : PgDn Cursor to beginning of line : Home Cursor to end of line : End Cursor to top of window : ^Home Cursor to bottom of window : ^End To beginning of file : ^PgUp To end of file : ^PgDn Current line to top of window : AltT Toggle insert/overtype : Ins Delete character under cursor : Del Delete previous character : ^H New file : AltN Read file : AltR Write block : AltW The Text Editor 23 Save file : AltS Open window : ^O Close Window : ^C Next window : F2 Previous window : aF2 Split screen : ^S Mark beginning of block : F7 Mark end of block : F8 Goto beginning of block : AltB Goto end of block : AltE Clear block marks : AltH Copy block : AltC Delete block : AltD Move block : AltM Search forward : F5 Search backwards : aF5 Replace forward : F6 Replace backwards : aF6 Global replace : ^F6 Repeat last search/replace : F1 Goto next error : ^E Goto previous error : ^P Goto line : AltG Set options : AltO Redraw the screen : ^L Quit : AltQ The Text Editor 24 Chapter 6 The Linker The linker is invoked by the command line M2LINK myprog [/s n] [/h n] [/o] [/p] [/l] where 'myprog' is the main module of the program you are creating. The options are thus: /s n n is the size of the stack to allocate (default is 4096). /h n n is the amount of space to reserve for the heap (in paragraphs). The default is all the free memory. /o invokes the optimizer. The optimizer prevents the output, to the object file, of all the procedures that are part of included modules but are not referenced. This will make your final EXE files smaller. /p tells the linker to include the profiler (M2Prof.M2O). For further information, see the chapter on "Utilities". /l tells the linker to process the line number information in the .M2O files and include it in the .DBG file. This option is disabled if the optimizer is invoked. /k tells the linker to ignore module keys, i.e. to not check for module version compatibility. This option should be used with extreme care. The linker creates two files: the .EXE file is your executable program, the .DBG file is a file containning symbol information for use by other utilities (see Map file generator, Profiler). The Linker 25 6.1 Module keys The module header record and the import records written out by the compiler to the object file are stamped with the date of the .DEF file that was processed - this becomes the module key. The linker will assure that these module keys in the module header of the imported module and in the import record match; If they do not match, both modules were not compiled using the same definition module. Because of the use of module keys, it is imperative that the date of the distributed .DEF files not be modified unless you intend to recompile the implementation modules. The Linker 26 Chapter 7 Other utilities 7.1 Editor keyboard configurator This program lets you define the keystrokes to be used to invoke all the editor commands. Invokation: EDCONFIG You will be prompted for a log file (default M2ED.HLP), a text file in which all of your configuration choices will be saved. You could print this file to create a quick reference card. EDCONFIG will then prompt you for the key sequence to be used for each editor command. For each command, EDCONFIG will also give you the option of defining an alternate key sequence. Once you have run through all the commands, the program will prompt you for an output file, the default being 'M2ED.CFG'. 7.2 Map file generator Invokation: DBG2MAP module_name Reads the .DBG file created by M2LINK and creates a DOS LINK compatible .MAP file. Other utilities 27 7.3 Make and the Makefile generator These utilities eliminate the burden, on the user's part, of having to figure out which modules are affected and, therefore, need to be recompiled as a result of any changes to particular definition modules. GENMAKE creates the .MAK file, the file with all the dependencies (this is the hard part) whereas MAKE (built into the compiler) will insure that these dependencies are observed when updating the object files. GENMAKE Invokation: GENMAKE main_module_name generates the .MAK file containning all the module dependencies for the named program. It does this by reading all the IMPORT statements in the main module and, recursively, generating the dependency lists for all those modules (but only the ones that can be found in the current directory!). GENMAKE will indeed read all the .MOD and .DEF files involved. MAKE invocation: see "Running the Compiler". MAKE will invoke the compiler as needed to assure that all the dependencies in the make file are observed. MAKE is dumb in that it will just run through the makefile sequentially. It was GENMAKE's responsibility to see that the dependencies are listed in a proper sequence. Please keep this in mind if you should edit a makefile! 7.4 The execution profiler When you link your program with the /p option, the module M2Prof is included in the output generated. When you execute the program, the profiler will ask you for the name of the .DBG file to use and give you an option of profiling your entire program (generating an execution profile by module), a particular module (generating an execution profile by procedure in that module) or a particular procedure (generating an execution profile by line in the procedure). Other utilities 28 Upon program termination, the profiler outputs the list of all the modules/procedures/lines profiled, ranked by execution time, to a file of your choice. This profiler is not that versatile, but it is useful nevertheless. It proved instrumental in pinpointing some obvious areas for improvement in the compiler (Oh, we did not tell you, did we? This compiler was written in the language it compiles -- Modula-2 -- and this system was used as our primary development tool since very early in the development process). Other utilities 29 Chapter 8 The Library Modules For complete information on what each library module provides, as well as its proper usage, please look at the .DEF files. In addition, the source code of all the library modules is available to all the registered users (see the order form in the back of this document for details). The Library Modules 30 Chapter 9 Shareware This software package is distributed under the "user supported" concept. This software can be freely distributed, as long as no money is charged for it, all the files are included, unmodified, and with their modification dates preserved. If you are going to place this software on a bulletin board (we thank you for it), please upload it in a library format (we suggest ARC) that will preserve this package's integrity. This software cannot be distributed as a part of, or in conjunction with, another product. This software cannot be used in a commercial environment without the payment of a $25 license fee per copy. Please feel free to contact us if you would be interested in a site or corporate license. The "user supported" form of distribution can be in the best interest of all concerned, if we consider the following: (1) users are given the opportunity to try, without pressure, the software to determine its suitability for some intended purpose; and (2) we eliminate the high cost of publishing and advertising (our users do it for us) and can, therefore, provide the same product for less. Our success will depend not only on the quality of this software but on the willingness of every individual user to "support" its developers. If you use this product, please send in the registration form in the back of this document, along with your registration fee. For $35 we will send you the latest version of this software and, as a token of our appreciation, all the library and runtime support source code (what a bargain!). This source code is made available to registered users only! Whether or not you decide to use this product, please give complete copies of this software to others (the more the better). You are an integral part of our distribution channel! Shareware 31 Chapter 10 Your input matters to us You can bet that this is serious! We know, and you know, that there are many ways in which this system can be improved. It is in our common interest that we agree on just how (what needs changing, what additional capabilities are needed) and when (let's take care of the more important stuff first!). Maybe you like this software so much that you would hate to see us improve it in the wrong direction (ha, ha, ha)... Maybe you find some weaknesses in this product that make it awkward to use. Maybe even (God forbid!) that one or more of those weaknesses make this software unusable for your purposes. Whichever the case may be, we need to know about it, our future is at stake!!! So, please!, fill out the survey form and send it in. Your input matters to us 32 Your comments would be appreciated Where did you get this software from? ( ) us ( ) a bulletin board ( ) a friend ( ) a computer club ( ) a shareware software distributor ( ) other ________________________ Systems you intend to use this software on ( ) PC (8088/8086) ( ) AT (80286) ( ) 80386 Typical system's configuration ( ) hard disk ( ) 512k ( ) 640k ( ) extended memory ( ) EGA adapter ( ) VGA adapter What programming languages do you use regularly? --------------------------------------------------------- Please rate the relative desirability of the following. Most desirable gets a 1, second gets a 2, etc. Could care less gets a 0. Immediate requirement gets an *. Documentation ( ) language tutorial to be included in the documentation ( ) complete language reference manual ( ) other: _________________________________________ The compiler ( ) compatibility switch to accept 2nd edition Modula-2 ( ) symbolic debugger ( ) improved space efficiency ( ) improved compiler speed ( ) ability to create .OBJ files ( ) inline 8087/80287 code generation ( ) floating point library to detect presence of 8087/80287 ( ) code generation for the 80286 (in real mode) ( ) code generation for the 80386 (real mode or V8086) ( ) additional memory models - only one available is huge ( ) tiny ( ) small ( ) medium ( ) compact ( ) large The editor ( ) support for EGA modes ( ) mouse based editor (in graphics mode) Integration: ( ) availability of freestanding editor ( ) availability of freestanding compiler ( ) add more integrated tools: _______________________________________ _______________________________________ How could we improve the compiler? _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ What features would you like to see in the editor? _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ How could we improve the development environment? _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ _____________________________________________________________ Other comments: BUG REPORT We would like to think that our software is bug free, but we have been around a while. Someone once wrote that a bug free program is a program whose bugs have not been uncovered yet. So, if you uncover one of those nasty critters, please provide us with the information below, and whatever else that may help us duplicate the problem. Name_____________________________________________ Company__________________________________________ Address__________________________________________ City, State, Zip_________________________________ Telephone _____________ Version of the software in use: ___________________________ Machine in use (make and model): ___________________________ Memory / Disks / Display type: ___________________________ Operating system used: ___________________________ Other system information that may be pertinent (PATH settings, CONFIG.SYS contents,...) Problem description: ORDER FORM Mail this form to: Fitted Software Tools P.O.Box 956129 Duluth, Ga 30136 to register your copy/copies of the Modula-2 compiler and/or register/order additional copies. We distribute the software and documentation on 360k floppies. A printed version of the manual is not available. The unauthorized distribution of the library and runtime support source code included in the distribution disks that you receive when you order a registered copy or update is specifically prohibited. This source code is made available to registered users only. If you are ordering multiple copies for your organization, we would suggest that you order 1 of the $35 packages and the rest as $25 registrations. You may then distribute the number of copies that you ordered from the master that you receive. Name_____________________________________________ Company__________________________________________ Address__________________________________________ City, State, Zip_________________________________ QTY ___ X Registration @ $25.00 _________ ___ X Registration & latest version @ $35.00 _________ Total enclosed: _________ [We will start shipping software orders during the first week of August 1987. We thank you for your patience and your support.] Table of Contents Chapter 1 Introduction 2 1.1 Hardware requirements 3 1.2 Software requirements 3 Chapter 2 Software installation 4 2.1 Theory 4 2.2 Recommended setup for a system with 2 floppy drives 5 2.3 Recommended setup for a hard disk system 6 Chapter 3 A little tour through the system 7 Chapter 4 The Compiler 10 4.1 Running the compiler 11 4.2 The compilation process 12 4.2.0.1 The input file 12 4.2.0.2 The imported modules 12 4.2.0.3 The output file 12 4.2.0.4 A warning 12 4.3 Compiler directives 13 4.4 Runtime errors 14 4.4.1 Trapping runtime errors in your program 14 4.5 Compiler size limits 14 4.6 The language supported 15 4.6.1 LONGINT and LONGCARD 16 4.6.2 Additional standard procedures 16 4.6.2.1 NEW and DISPOSE 16 4.6.2.2 LONG and SHORT 17 4.7 Objects exported by the pseudo module SYSTEM 17 4.7.0.1 TYPE BYTE 17 4.7.0.2 TYPE WORD 17 4.7.0.3 TYPE ADDRESS 18 4.7.0.4 SEG and OFS 18 4.7.0.5 PROCEDURE ADR 18 4.7.0.6 PROCEDURE FLAT 18 4.7.0.7 PROCEDURE PTR 18 4.7.0.8 PROCEDURE NEWPROCESS 18 4.7.0.9 PROCEDURE TRANSFER 18 4.7.0.10 PROCEDURE IOTRANSFER 19 4.7.0.11 ASSEMBLER 19 4.8 The generated object code 20 4.8.1 Data type representation 20 4.8.2 The runtime memory map 21 4.8.3 Procedure calling conventions 22 4.8.3.1 Parameter passing (all except open array parameters) 22 4.8.3.2 Parameter passing (open array parameters) 22 Chapter 5 The Text Editor 23 Chapter 6 The Linker 25 6.1 Module keys 26 Chapter 7 Other utilities 27 7.1 Editor keyboard configurator 27 7.2 Map file generator 27 7.3 Make and the Makefile generator 28 7.4 The execution profiler 28 Chapter 8 The Library Modules 30 Chapter 9 Shareware 31 Chapter 10 Your input matters to us 32