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CBL-CMPT.DOC File Compatibility with Previous Releases of Microsoft(R) COBOL (C) Copyright Microsoft Corporation, 1991 Contents -------- Introduction Changes in Microsoft COBOL 4.5 Changes in Microsoft COBOL 4.0 Documentation Introduction ------------ This document is for use when maintaining applications created using earlier releases of this product. It describes the differences that may cause problems, and includes documentation of features no longer documented in this system, but maintained for compatibility. Note that the use of the compiler with default settings will cause the use of new words to become reserved. A list of these words is given below. Changes in Microsoft COBOL 4.5 ------------------------------ Compiling o Use of the MF directive when compiling will cause some data names to be illegal as the reserved word list has been extended. Change the dataname, use the REMOVE(reservedword) directive or recompile with MF(6). New reserved words included when using MF(7) are: ALPHABET ALPHABETIC-LOWER ALPHABETIC-UPPER ALPHANUMERIC ALPHANUMERIC-EDITED ANY BINARY CLASS COMMON COMP-1 COMP-2 COMP-4 COMPUTATIONAL-1 COMPUTATIONAL-2 COMPUTATIONAL-4 CONTENT CONTINUE CONVERTING CYCLE DAY-OF-WEEK DBCS DISPLAY-1 EJECT END-ADD END-CALL END-COMPUTE END-DELETE END-DISPLAY END-DIVIDE END-EVALUATE END-IF END-MULTIPLY END-PERFORM END-READ END-RECEIVE END-RETURN END-REWRITE END-SEARCH END-START END-STRING END-SUBTRACT END-UNSTRING END-WRITE EOL EOS EQUALS EVALUATE EXCEEDS FALSE FUNCTION GLOBAL ID INITIALIZE LOWLIGHT NUMERIC-EDITED ORDER OTHER PACKED-DECIMAL PADDING PARAGRAPH PURGE REFERENCE REPLACE SKIP1 SKIP2 SKIP3 SORT-RETURN STANDARD-2 TEST TIME-OUT TIMEOUT TITLE TRUE UNEQUAL WAIT WHEN-COMPILED Note that most of these words are already reserved under the ANS85 or VSC2 directives, so will only become new if you are compiling with MF but without ANS85 or VSC2. o RM compatibility When compiling for RM compatibility, if the same behavior is required as with Microsoft COBOL 4.0 then you should compile with the DETECTLOCK directive. o ASSIGN TO PRINTER Files defined with ASSIGN TO PRINTER are treated as LINE ADVANCING in COBOL 4.5. In 4.0, they were treated as LINE SEQUENTIAL. o NEXT SENTENCE In COBOL 4.0, you could make NEXT SENTENCE jump to the appropriate end-scope delimiter by using the MF"5" directive (see below). In 4.5 this directive does not have this effect. o Nested Programs In V4.0, nested programs could have Configuration Sections. In V4.5 they cannot. o The "DISPLAY ... UPON CRT Attributes Behavior" switch S6 is no longer documented in the Operating Guide. Here is its description. With the Enhanced DISPLAY (see the Screen Handling chapter of the Language Reference Manual), if no attributes are specified on the DISPLAY then, by default, the attributes already existing in the given area will be used. If the switch +S6 is specified at run time the normal screen attributes will be used instead. o In earlier versions of this COBOL system all system library routines were call-by-number. Many of the call-by-name routines in the present product replace old call-by-number routines. The list below indicates, for each call-by-name routine that has replaced a call-by-number routine, the number of the routine it has replaced. In some cases the call-by-name routine has additional features. Name Number ---- ------ CBL_READ_SCR_CHARS B7 0 CBL_READ_SCR_ATTRS B7 2 CBL_READ_SCR_CHATTRS B8 0 CBL_WRITE_SCR_CHARS B7 1 CBL_WRITE_SCR_ATTRS B7 3 CBL_WRITE_SCR_CHATTRS B8 1 CBL_WRITE_SCR_TTY 82 CBL_WRITE_SCR_N_CHAR B7 4 CBL_WRITE_SCR_N_ATTR B7 5 CBL_SWAP_SCR_CHATTRS B8 2 CBL_GET_SCR_SIZE E3 CBL_SET_CSR_POS E6 CBL_CLEAR_SCR E4 CBL_GET_KBD_STATUS D9 PC_READ_DRIVE 91 5 PC_SET_DRIVE 91 6 CBL_READ_DIR 91 7 CBL_CHANGE_DIR 91 8 CBL_DELETE_FILE 91 18 CBL_RENAME_FILE 91 17 PC_TEST_PRINTER B0 7 CBL_SPLIT_FILENAME 8C CBL_JOIN_FILENAME 8D o The behavior of COPY ... REPLACING has been changed depending on the setting of the ANS85 or VSC2(3) directives. Previously all non-COBOL characters were disallowed in operands to COPY ... REPLACING, and lowercase and colon were added to the character set. This behavior now only occurs if the ANS85 or VSC2(3) directive is used. Otherwise, the operands may contain non-COBOL characters. Changes in Microsoft COBOL 4.0 ------------------------------ General o When installing on an OS/2 system, SETUP will add PATH and environment variable information to CONFIG.SYS and not to OS2INIT.CMD as in previous releases. This conforms with the standard for installing OS/2 v1.1 and later. o The files, DBCS.EXE/.DLL and V-ISAM.DLL are no longer required, and are not included with this release. o The shared run-time files, COBLIB.DLE and COBLIB.DLL are used by the components of this system, and must be loaded for the system to operate. COBLIB.DLE is required for DOS, COBLIB.DLL for OS/2. o The callable file handler interface is no longer part of this product. If you wish to use the CALLFH feature, or to call the file handler directly, you will require a copy of the Micro Focus COBOL/2 Toolset. Compiling o The default directives, NOCOPYLBR, ANS85, NOOSVS and MF are now built into the compiler and are not included in the COBOL.DIR created by SETUP. ANS85 and OSVS can be changed by SETUP, so that NOANS85 and/or OSVS are included in the COBOL.DIR created by SETUP. SETUP also allows selection of SAA and the default linking libraries. o VSC2 is now equivalent to VSC2(3). Previously VSC2 was equivalent to VSC2(2). The directives VSC2 OLDVSC2 have been replaced by VSC2(1). o The directive OLDFILEIO has been replaced by the directive IDXFORMAT which defines the type of indexed file required. IDXFORMAT"2" is equivalent to OLDFILEIO. o The verb, GOBACK, and the special register, RETURN-CODE are now part of the standard Micro Focus(R) COBOL language and can be used without needing VSC2 or OSVS. They are enabled by an MF level of 5 or above (on by default) and can, therefore, be disabled by specifying MF(4). o Comments following the PROGRAM-ID, which were allowed in previous versions, are now not allowed by default. They can, however, be enabled using the PROGID-COMMENT directive. o For interfacing at the assembler level, note that the object segment class names created by the COBOL compiler have changed in this release. o The default ALPHASTART value has been set to 1 to conform to the ANSI'85 standard. In previous versions, this was set to 0. If you have programs that use the ALPHABET clause of the SPECIAL-NAMES paragraph, you may need to specify the directive ALPHASTART"0" to maintain the required behavior. o ACCEPT .. FROM DAY-OF-WEEK The statement ACCEPT data-item FROM DAY-OF-WEEK incorrectly returned the value 0 for Sunday. It now returns a value of 7, as documented. o COMP-5 The default behavior of USAGE COMP-5 data items has been changed. In previous versions of the product, COMP-5 was treated in a similar fashion to signed COMP. It is now treated in a similar fashion to COMP-X, allowing it to be a true binary numeric item using machine specific byte ordering. This makes it a very efficient data type. If you use COMP-5 in existing programs, and depend on its sign handling, you should compile your programs with the COMP-5"1" directive. o NEXT SENTENCE NEXT SENTENCE is handled differently in this version of the product. In previous versions NEXT SENTENCE would cause control to move to the end of the sentence (i.e. following the next period) or to the statement following the next end-scope delimiter. In this version, it will always go to the end of the sentence, as defined by the ANSI'85 standard. If your program uses NEXT SENTENCE and relies on the change of control being to the appropriate end-scope delimiter, you can use the MF"5" directive (but see above for V4.5). Alternatively, change the NEXT SENTENCE phrases to CONTINUE, which will have the desired effect. o SYMBOLIC CHARACTERS clause The default SYMBSTART value has been set to 1 to conform to the ANSI'85 standard. In previous versions, this was set to 0. If you have programs that use the SYMBOLIC CHARACTERS clause of the SPECIAL-NAMES paragraph, you may need to specify the directive SYMBSTART"0" to maintain the required behavior. o RECORDING MODE The RECORDING MODE phrase has been amended so that, when it is explicitly included in an FD, it overrides the RECORD clause in all cases, with RECORDING MODE F always causing a fixed format file to be created, and RECORDING MODE V a variable format file. If you require the original behavior, whereby RECORDING MODE is overridden by the RECORD clause, then use the MF"5" directive. Note that the RECMODE directive will not override the RECORD clause. o REPORT-WRITER reserved words The RW directive has been made obsolete by incorporating the REPORT- WRITER reserved words into the main dialects that support REPORT- WRITER. If you have a program that uses some REPORT-WRITER reserved words as data names, and used to be compiled with the NORW directive, then you need to replace the NORW directive by USE(NORW). This will cause the REPORT-WRITER reserved words to be removed from the reserved word list, making them available for use as data names. o INSPECT The handling of the LEADING phrase in INSPECT has been amended to make it conform to a recent interpretation of the ANSI'85 standard. For example, if data-stream contains "//AAA BBB OOO CCC", the statement INSPECT data-stream TALLYING count-field FOR LEADING "A" "\" " "O" "C" returned the value 5 in count-field in previous versions, but now returns the value 2. This is because the remaining characters in the LEADING phrase are considered to be ineligible once a match has been found on one of the characters. o COPY filenames Since this version now distinguishes between filenames with no extension, but with a trailing period, and those without a trailing period (treating the former as a specified extension of spaces), some COPY statements in existing programs may appear to stop working. If you want your copy files to have extension .CPY, but code them in your program with no extension, then you must be sure that the name does not have a trailing period. For example, change: COPY "mycopy.". to COPY "mycopy". Note that COPY mycopy. is treated as if it has no trailing period, and hence as in previous versions. Running o A large number of the run-time system subprogram calls, provided in earlier releases as call-by-number calls, have been replaced by named calls. In addition to making the calls easier to remember and use, the call-by-name calls can accept parameters defined in any part of the data division. The replaced call-by-number calls are still supported in this release, and documented below. However, we recommend that you replace them with the equivalent call-by-name calls as appropriate. o Record sizes In previous releases, the maximum and minimum record sizes specified for a variable format file had to be the same in every program referencing the file. This restriction has been removed, allowing programs to specify record lengths different to those specified in the program used to create the file. However, if an attempt is made to write a record which is smaller than the smallest defined or larger than the largest defined a run-time error, 9/044, will be returned. Animating o The method required to animate programs has changed in this release. When a program is compiled for animation, using the ANIM directive, intermediate code files are packaged into .OBJ files and .DLL on OS/2). These .EXE/.DLL files can be animated in the usual way. The pure intermediate code files (.INT) are no longer required for animation. o Since the new animation method incorporates a link step, any non- COBOL .OBJ files can be linked in prior to animation. These will operate correctly when encountered, though always in zoom mode. This new technique makes IANIM and augmented INT obsolete, and these facilities are not supported in this release. The same method allows OS/2 API function calls to be resolved prior to animation, avoiding the need for the Install Function technology of earlier releases. o This release has the +F switch set by default. This will cause illegal data in numeric fields to be trapped during animation, and when running intermediate code .OBJ files (run-time system error 163). This may cause existing programs to fail where they previously worked. However, trapping such instances will help prevent the subsequently generated code from failing. All generated programs will work as at present, always assuming that numeric fields contain numeric data. Linking o The linking library, OS2.LIB, should be used instead of DOSCALLS.LIB when linking applications for use on OS/2(tm). OS2.LIB is supplied as part of the utilities. (DOSCALLS.LIB can be used provided the application is not a Presentation Manager application.) o The /NOP option is no longer required when linking for use on OS/2. o The default environment for applications created using this release is the shared run-time environment. This is particularly recommended for use on OS/2, where a single copy of COBLIB.DLL can be shared by any COBOL application (built to use COBLIB) running in any OS/2 session. To use this environment, the application is linked in the usual way, using the libraries, COBLIB.LIB, and COBAPI.LIB or OS2.LIB depending on DOS or OS/2. The EXE files produced will be much smaller since little run-time system code is included directly. System programs, such as EXTFH and ADIS, can be linked in with the application, or linked as standalone sub-programs. Again, for OS/2, if linked as standalone .DLL files, they can be shared by any number of COBOL applications. Notes: - These system programs MUST be linked with COBLIB for use with COBLIB applications. - Modules linked with COBLIB cannot be mixed with modules linked with LCOBOL. Hence, applications must be either all LCOBOL or all COBLIB. However, COBLIB applications and LCOBOL applications can be run on the same environment as long as they don't try to call each other. o The linking library (.LIB) files supplied with the system have been split in a different way to enable reduced disk usage. They now consist of LCOBOL.LIB, COBLIB.LIB, and COBAPI.LIB. The new LCOBOL is equivalent to the old PCOBOL. The addition of COBAPI.LIB to LCOBOL.LIB gives the old LCOBOL. (Users may like to recombine these libraries using LIB if they wish to retain old working practices.) For OS/2 operation, LCOBOL.LIB is used in combination with OS2.LIB (which supersedes DOSCALLS.LIB). In the shared run-time system, the default, COBLIB.LIB, is equivalent to the old PRCOBOL.LIB. Again, either COBAPI.LIB or OS2.LIB is used in combination with COBLIB.LIB to complete the linking for DOS or OS/2 respectively. Applications linked with these libraries will be very much smaller, benefiting from the shared run-time system support in COBLIB.DLE and COBLIB.DLL. (Note that the application itself can be bound so that it will run on both DOS and OS/2 provided both shared run-time system files are present.) o If you select a linking environment other than the built-in default, SETUP will create a default LINKLIB in your COBOL.DIR. The default, and equivalent of earlier releases, is LINKLIB(LCOBOL+COBAPI). If you normally use the system on OS/2, use LINKLIB(LCOBOL+OS2). With this release, the default is to use the COBLIB shared run-time system, requiring LINKLIB(COBLIB+COBAPI) on DOS, and LINKLIB(COBLIB+OS2) on OS/2. When the default has been set in this way, you can still link for use in other environments by specifying the relevant libraries on the LINK command line. However, you should use the /NOD directive when doing so, otherwise link-time errors may occur. o The file handler for indexed files, IXSIO, has been replaced by the external file handler, EXTFH. This can be linked in exactly the same way as IXSIO in earlier releases, either linked in with the application or linked as a standalone system program. Programs referencing ANSI'85 EXTERNAL files and normal indexed files now only use EXTFH rather than two separate file handlers. Compatibility issues Compiling o If you compile your programs on OS/2 using batch files, you will need to alter the batch files to compile using the command COBOL instead of PCOBOL. Alternatively, you can copy COBOL.EXE to PCOBOL.EXE in the COBOL system directory. o Programs previously compiled without the ANS85 directive, if recompiled under this default system, may not work correctly. The most likely cause is that the new system has ANS85 on by default. This causes all file status codes to be ANS85 not ANS74 statuses. The problem can be avoided by using the NOANS85 directive when compiling any program that is designed to work with ANS74 file statuses. Animating o The compiler dictionary structure has been amended. This means that IDY files created by earlier releases will not be compatible with ANIMATOR in this system. Hence, you should recompile, with this release of the compiler, any program you wish to animate. Linking o .OBJ files created by this release are not compatible with .OBJ files created by earlier releases. Hence, if you need to rebuild an application where one of the OBJs has been created using this release, you must recompile all the programs with this release of the compiler before linking. Running o In previous versions of this software, an error is given when an indexed file is opened if the record lengths of the file do not exactly match those given in the FD. This has been changed so the error is only given if an attempt is made to WRITE a record larger than the maximum or smaller than the minimum. o The Report Writer module has been changed so that it is compatible with IBM(R) OS/VS COBOL when the OSVS directive is used. This is the ANSI'68 COBOL standard. In previous versions, the default with OSVS was ANSI'74 COBOL standard report writer. You may have report writer programs using OSVS features, but requiring ANSI'74 report writer compatibility. This mix is no longer possible, and you will either need to remove the OSVS features (try VSC2), or accept ANSI'68 COBOL report writer standard. Documentation ------------- Call-by-number subprogram calls. Many of the COBOL system library routines provided in earlier releases as call-by-number have been replaced by call-by-name routines. We recommend that you replace all call-by-number routines by their equivalent call-by- name routines. See your Operating Guide chapter, COBOL System Library Routines, for details of which call-by-name routines replace these. To allow you to maintain existing applications, the documentation for the replaced call-by-number routines follows: PUT A CHARACTER TO THE SCREEN CALL X"82" USING character. where: character is a PIC X field containing the character to be put on the screen in the current cursor position. The cursor is then advanced one position to the right, or onto the next line if it is in the rightmost position, or off the screen if it is in the bottom right-hand corner. READ A CHARACTER FROM THE KEYBOARD CALL X"83" USING character. where: character is a PIC X field to contain the character returned. Notes: 1. A call on this subprogram also causes the function key table to be checked and the result byte updated. 2. If the character returned from this subprogram is a carriage- return character (hex 0D), then the character read from the keyboard has been recognized by the function key table, and the result byte of that table should be checked to determine the actual character which has been pressed. 3. If the character read is a 2-byte character (such as a function key) and it was not matched in the function key table, then both bytes are returned to this subprogram. The first call returns a null byte (hex 00) and the next call returns the scan code (refer to the IBM Personal Computer Technical Reference Manual for details of scan codes). 4. Break can be used to interrupt a running program. However, if the program was in the middle of a call to this subprogram at the time, nothing happens until the call on this subprogram is satisfied by reading another character from the keyboard. Break is not returned by this routine. SCREEN INPUT AND OUTPUT CALL X"B7" USING function, parameter, buffer where: function is a PIC 99 COMP-X data item and contains a value: 0 to read characters from the screen 1 to write characters to the screen 2 to read attributes from the screen 3 to write attributes to the screen 4 to clear characters from the screen 5 to clear attributes from the screen parameter is a group item consisting of three data items: o a PIC 9(4) COMP-X field showing the length of the data to be read or written. o a PIC 9(4) COMP-X field giving the start position on the screen. Top left is position 1, 81 is the start of the next line, etc. o a PIC 9(4) COMP-X field showing the start position in the buffer. The starting buffer position is 1. buffer is the COBOL data area. It is a PIC X(n) field and may be as large or small as you require to write your data. An entire screen of text or attributes is 2000 bytes. No check is made that any data to be read will fit into your buffer. Therefore, if the length specified is greater than the length available in your buffer, any subsequent data will be corrupted. Buffer is not used with a function of 4 or 5, but this parameter must still be supplied. Note: When writing or clearing characters, the User attribute is imposed on the character position, unless the User attribute flag is set off, in which case the current Screen attribute for that character position is used. SCREEN CELL INPUT AND OUTPUT CALL X"B8" using FUNCTION PARAMS CHARBUFF ATTRBUFF where parameters are: 01 FUNCTION PIC 9(2) COMP-X = 0 to read screen to character and attribute buffers = 1 to write screen from character and attribute buffers = 2 to swap screen with character and attribute buffers 01 PARAMS 03 P-LENGTH PIC 9(4) COMP-X. 03 P-SOFFSET PIC 9(4) COMP-X. 03 P-BOFFSET PIC 9(4) COMP-X. P-LENGTH = number of screen cells to read/write/swap P-SOFFSET = screen offset (1 = top left) P-BOFFSET = buffer offset (1 = start of buffer) 01 CHARBUFF 03 CHARS PIC X OCCURS n TIMES = an array of character bytes 01 ATTRBUFF 03 ATTRS PIC X OCCURS n TIMES = an array of associated attribute bytes TEST CONSOLE STATUS CALL X"D9" USING parameter. where: parameter is a PIC 99 COMP-X field and shows the status of the console: zero there is no character waiting to be read from the keyboard non-zero there is a character waiting to be read from the keyboard When a program is being animated in other than zoom mode, this function always returns a zero (i.e., it never detects a character), because ANIMATOR always looks for characters. However, the function operates correctly when zoom mode is used. GET SCREEN SIZE CALL X"E3" USING no-lines, no-cols. where: no-lines is a PIC 99 COMP-X field and shows the number of lines on the screen. no-cols is a PIC 99 COMP-X field and shows the number of columns on the screen. CLEAR SCREEN CALL X"E4". This routine clears the entire user screen. MOVE THE CURSOR TO A DEFINED POSITION CALL X"E6" USING result, parameter. where: result is a PIC 99 COMP-X field. It is not used. parameter is a group item consisting of two data items: o a PIC 99 COMP-X field specifying the row number for the cursor to be moved to; in the range 0 to 24. o a PIC 99 COMP-X field giving the column number for the cursor to be moved to; in the range 0 to 79. ========================================================================== Copyright (C) 1991 Microsoft Corporation Copyright (C) 1991 Micro Focus Ltd