Kednos PL/I for OpenVMS Alphatm Release Notes for Version 4.4B
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1. This problem has been corrected in the PLI STARLET TLB text library 35 CF S 11730 UVO101501 A PL 1 Runtime error caused a program abort Get file list caused a program to crash with an I O Error This problem has been corrected in the DEC PL I Run Time Library 36 CF S 16774 MGO100757 The FREE statement freed neither the most recent nor any generation of a controlled variable eventually exhausting memory This problem has been corrected in the DEC PL I Run Time Library 38 CF S 9384 VN 0100006 Deleting a nonexistent keyed record caused program to abort with a PL I internal RAB condition This problem has been corrected in the DEC PL I Run Time Library 39 CF S 22126 When specified in the declaration statement for a file the MAXIMUM_ RECORD_SIZE ENVIRONMENT option was ignored and DEC PL I opened the file with incorrect attributes This problem has been corrected in the DEC PL I Run Time Library 44 CF S 23922 Preface The built in function INDEX returned incorrect results when used on a string with with null characters such as BYTE 0 This problem has been corrected in the DEC PL I Run Time Library 46 CF S 23591 The FLOOR built in function performed poorly for fixed binary numbers The function has been improved to provide better performance in the DEC PL I Run Time Library 47 CF S 23589 The DEC PL I RTL did not expect to encounter a PLI _ENDPAGE condition which did not have an associated F2. end put skip list shouldnt be here 5 end nested_proc2 proc returns float begin begin begin begin begin return 5 1 end put skip list shouldnt be here 1 end put skip list shouldnt be here 2 end put skip list shouldnt be here 3 end put skip list shouldnt be here 4 end put skip list shouldnt be here 5 end program proc options main dcl result1 fixed dcl result2 float result1 result2 nested_proc nested_proc2 put skip list result1 put skip list result2 end Two special considerations should be observed for nonlocal returns from OPTIONS MAIN procedures First an ON unit declared in the scope of one of the BEGIN END pairs for FINISH is given a chance to execute Second an ON unit declared in the scope of one of the BEGIN END pairs for VAXCONDITION SS UNWIND is NOT be given a chance to execute with the above construct e When a main program for example pname procedure options main terminates abnormally due to an unhandled exception DEC PL I closes all open files before turning control over to the OpenVMS last chance condition handler the utility that prints the error and traceback 18 Preface This means that I O that was being held in a buffer is allowed to reach its destination before the error dump appears on the screen This is not the case with VAX PL I in which I O held in a buffer is not allowed to
3. 18 36 fixd22 22 40 fixd21 fixd18 fixd22 fixb30 fixd21 fixd18 18 42 fixd24 24 58 fixd21 fixd24 fixd18 fixb30 fixd21 end 11 1 Corrected Compiler Errors Corrected compiler errors are as follows e VAX PL I Version 3 5 produced an incorrect result when both the SELECT and WHEN clauses of a SELECT statement contained a substring expression Local memory for the first substring may have been overwritten by the second substring This error has been corrected in DEC PL I Version 4 0 The code that produced an incorrect result the value 1 instead of the correct value of 2 is as follows 21 Preface p procedure options main dcl txt char 3 dcl n_chars fixed binary 31 dcl option fixed binary 31 txt NUM n_chars 2 SELECT SUBSTR txt 1 n_chars WHEN SUBSTR LOG 1 n_chars option 1 WHEN SUBSTR NUMBER 1 n_chars option 2 OTHERWISE option 0 END put skip list Option is gt option END e VAX PL I bugchecks when trying to initialize arrays of areas with one PL I assignment DEC PL I has corrected this problem The following example shows the VAX PL I behavior p procedure options main dcl array 10 area array empty end To avoid this error initialize arrays of areas by means of a DO loop when using VAX PL I 11 2 Corrected Documentation Errors 22 The errors in this section have been corrected in the current v
4. PUT SKIP 2 LIST High Order 32 bits RO CHF IL_MCH SAVRO_HIGH PUT SKIP 2 LIST Low Order 32 bits R1 CHFSIL_MCH SAVR1_LOW PUT SKIP 2 LIST High Order 32 bits R1 CHF IL_MCH SAVR1_HIGH END 28 The following notes are keyed to Example 1 6 8 86 Preface The procedure includes the module CHFDEF from the default system library The ONARGSLIST built in function assigns a value to the pointer CHF ARGPTR declared in CHF DEF Using the CHF SIG_ARGS field in the signal array the procedure prints the number of arguments in the signal array It displays the contents of the first argument that is the condition value Because the number of arguments is variable the procedure uses the DIM built in function to determine the number of elements in the array CHF SIG_ARG this array always contains three fewer members than arguments in the array because the condition name PC and PSL arguments are always present After displaying the signal arguments the procedure displays the contents of RO and R1 from the mechanism array For more detailed information on the argument lists passed to a condition handler and for descriptions of the values in the signal array and mechanism array see the OpenVMS System Services Reference Manual Note that the PL I run time system signals conditions using the conventions for specifying signal arguments Specifically it passes arguments following the requi
5. The DEC PL I pre processor was limited to 253 characters string variables This problem has been corrected in the DEC PL I compiler 10 10 1 10 2 Preface Overview of New Features in Version 4 0 DEC PL I Version 4 0 is based on VAX PL I Version 3 5 DEC PL I Version 4 0 also includes support for IEEE floating point data Version 4 0A also contains the new features of Version 4 0 Overview of Language Support DEC PL I Version 4 0 is primarily a VAX PL I Version 3 5 compatibility release The following sections contain information on support or lack of support for language elements DEBUG Support DEC PL I Version 4 0 does not contain full debug support for the following PL I language data types e PL I unaligned bit string array variables with run time sizes and PL I parameter unaligned bit string array variables with run time sizes The following sample program shows an unaligned bit string array variable P procedure options main call pl 5 end pl procedure size_ch dcl size_ch fixed binary dcl rtbl size_ch bit 5 dcl rtb2 size_ch size_ch bit 5 end In addition on OpenVMS AXP you cannot correctly examine or deposit to any PL I unaligned bit string array variable of unknown size e PL I picture variable data type as the following program fragment shows declare p2 picture lt picture specification gt e PL I varying character variables with run time sizes as the following sample pro
6. Check that code does not exceed boundaries at compile time Problem Block I O s of greater than 32K fail Blocks I O s of 64k are supported on the VAX version Workaround Check that block I O s do not exceed the 32k limitation 13 Known Problems and Restrictions With Version 4 0 This section describes known problems with DEC PL I Version 4 0 Because DEC PL I Version 4 0 is based on VAX PL I Version 3 5 Digital recommends that you read the VAX PL I Version 3 5 release notes before submitting an SPR 13 1 Compiler Known Errors and Methods of Avoidance Known compiler errors and suggestions for avoiding them are as follows In VAX PL I and DEC PL I you can use the OTHERWISE option on a GOTO statement that transfers control to a label reference that is a subscripted label with a variable subscript An error is reported if you use the OTHERWISE option on a GOTO statement for a label reference that is a subscripted label without a variable subscript The latter construct is not recommended because it causes the compilers to bugcheck An example of such an inappropriate use of the OTHERWISE option follows program procedure options main goto part 2 otherwise part 2 end program To avoid this error use a variable subscript or remove the OTHERWISE option When you use the GOTO statement with the OTHERWISE option specify label array elements after the GOTO statment If you use potential label references for a sp
7. VAX Ada VAX BASIC VAX BLISS VMScluster CDD Repository VAX COBOL VAX DATATRIEVE VAX DIBOL VAX DOCUMENT VAX FORTRAN VAXinfo VAX MACRO VAX Pascal VAX SCAN VAXset VAXTPU and the DIGITAL logo 1 Contents PREFACE vi 1 OVERVIEW OF CHANGES MADE IN KEDNOS PL I VERSION 4 4B AND KEDNOS RUNTIME LIBRARY VERSION 4 4B 1 2 OVERVIEW OF CHANGES MADE IN RUNTIME LIBRARY VERSION 4 4 1 3 OVERVIEW OF CHANGES MADE IN VERSION 4 4 AND RUNTIME LIBRARY VERSION 4 3 1 4 OVERVIEW OF CHANGES MADE IN VERSION 4 3 AND RUNTIME LIBRARY VERSION 4 2 2 5 OVERVIEW OF CHANGES MADE IN VERSION 4 2 2 6 OVERVIEW OF CHANGES MADE IN VERSION 4 1 2 7 INSTALLATION INFORMATION 3 7 1 Kit Information 3 7 2 Compression of the PL I System Interface Library PLISSTARLET TLB 3 8 DETAILS OF CHANGES MADE IN VERSION 4 1 3 8 1 Corrected Documentation Errors 5 9 OVERVIEW OF CHANGES MADE IN VERSION 4 0A 5 10 OVERVIEW OF NEW FEATURES IN VERSION 4 0 10 10 1 Overview of Language Support 10 10 2 DEBUG Support 10 10 3 Differences in VAX PL I and DEC PL I Support for Floating Point Data Types 11 10 4 Support for Other Language Elements 12 Contents 11 OVERVIEW OF CHANGES FROM VAX PL I 13 11 1 Corrected Compiler Errors 21 11 2 Corrected Documentation Errors 22 12 KNOWN PROBLEMS AND RESTRICTIONS WITH VERSION 4 1 23 13 KNOWN PROBLEMS AND RESTRICTIONS WITH VERSION 4 0 23 13 1 Compiler Known Errors and Methods of Avoidance
8. 23 13 2 Run Time Library Known Errors and Methods of Avoidance 27 13 3 Known Errors in the PL I for OpenVMS Systems Documentation 27 EXAMPLES 1 Displaying Arguments Passed to a Condition Handler AXP __ 28 Preface vi This document contains release information on Kednos PL I Version 4 4B for OpenVMS Alpha Systems Release information is necessary for gaining the best results from Kednos PL I Version 4 4B on the OpenVMS Alpha operating system Kednos recommends that all users read this information Kednos Corporation also recommends that all users review the section of this manual entitled Known Errors and Restrictions before submitting an SPR Preface Overview of Changes Made in Kednos PL I Version 4 4B and Kednos Runtime Library Version 4 4B Kednos PL I Version 4 4B and Kednos Runtime Library Version 4 4B contain the following enhancements and fixes e A defect has been corrected whereby the signal SS I MGDMP was being intercepted and displayed chained with PLI ERROR rather than passed to VMS for processing e A defect has been corrected whereby signals displayed chained with PLI ERROR contained extraneous error messages chained onto the end e A separate Hobbyist license from K ednos is now required in addition to the OpenVMS Hobbyist license from HP Overview of Changes Made in Runtime Library Version 4 4 Kednos Runtime Library Version 4 4 contain the following enhancements and fixes e A defect
9. DEC PL I program resulted in a series of LINK W MULDEF warnings one for each of the following symbols DPLI MTH_EXT_MOD_DEC4 DPLI MTH_EXT_ADD_DEC4 DPLI MTH_EXT SUB DEC4 DPLI MTH_EXT MUL_DEC4 DPLI MTH_EXT_DIV_DEC4 DPLI HND_RAISE_CONDITION DPLISMEM_ASSIGN VSTR This problem has been corrected in the DEC PL I Run Time Library 22 CF S 19143 Declarations for the new SYS GET_ SECURITY system service were missing in the PLISSTARLET TLB text library Preface This problem has been corrected in the PLI STARLET TLB text library 25 CF S 20969 CF S 20969 SIGN builtin function returned incorrect results This problem has been corrected in the DEC PL I Run Time Library 27 CF S 21334 DEC PL I was not properly handling the ENDPAGE condition for file variables in certain cases The compiler allocates a condition handler control block which is then managed by the PL I RTL The compiler was allocating a fixed stack temp for this variable If an ON statement contains conditions which are not constant such as ENDPAGE with a file variable and if the ON statement is inside a loop context during the second iteration of the loop the information for the first execution of the ON statement was overwritten This caused the established condition to be forgotten by the RTL This problem has been corrected in the DEC PL I compiler 28 CF S 21453 Declarations for new symbols in CLIDEF were missing in the PLI STARLET TLB text library
10. LIB included in the DCLTABLES This problem has been corrected the DEC PL I installation procedure 12 CF S 16104 Preface Temporary stack space created for built in functions POSINT and INT are not cleaned up properly possibly leading to ACCVIO or VASFULL This problem has been corrected in the DEC PL I compiler 13 CF S 19495 The PL I COLUMN n output control format item was not correctly positioning the columns relative to the current position This problem has been corrected in the DEC PL I Run Time Library 16 CF S 19311 The DEC PL I compiler was stopping with a PLIG F BUGCHECK fatal error when the right hand side string in a preprocessor statement equals the string in a PICTURE declaration and the DEBUG compile command qualifier was used This problem has been corrected in the DEC PL I compiler 17 CF S 20493 34 CF S 11727 Definition of logical name SYSPRINT ignored by PL 1 This problem has been corrected in the DEC PL I Run Time Library 19 CF S 19310 The DEC PL I compiler was stopping with a PLIG F BUGCHECK fatal error instead of reporting a user error when a TYPE clausein a declaration incorrectly refers to an unknown variable This problem has been corrected in the DEC PL I compiler 20 CF S 19309 Fixed length record format sequential files could not be opened for keyed input using integer keys This problem has been corrected in the DEC PL I Run Time Library 21 CFS 19301 Linking a
11. is fetched not initialized 13 2 Run Time Library Known Errors and Methods of Avoidance These release notes for DEC PL I for OpenVMS AXP Version 4 0 include release notes for the OpenVMS AXP Run Time Library RTL as the DEC PL I for OpenVMS AXP Version 4 0 kit that you receive contains a special version of the Run Time Library in the DPLIVMS040 file In future releases OpenVMS AXP will supply the RTL as it has in the past and RTL release notes will be included with the OpenVMS AXP release notes Information in this section is listed by operating system version OpenVMS AXP Version 1 5 Environment Option FILE_ID_TO This option is supported only for temporary files In addition the option does not work if the default directory specification is a rooted directory Digital is unlikely to change this behavior because this option s rate of use is low If this restriction constitutes a serious problem for you please submit an SPR PL I FINISH condition and DEBUG In VAX PL I the EXIT command to the debugger raises the FINISH condition and issues a message that the debugger is finishing DEC PL I does not raise the FINISH condition due to architectural differences between OpenVMS VAX and OpenVMS AXP 13 3 Known Errors in the PL I for OpenVMS Systems Documentation The known errors in the PL I for OpenVMS OpenVMS documentation are as follows PL I for OpenVMS Systems Reference M anual The title page the manual accompanying DE
12. reach its destination before the error dump appears on the screen Differences in exception handling between OpenVMS AXP and OpenVMS VAX Since machine instructions on Alpha AXP tm differ from those of the VAX any exception handler written to handle VAX hardware exceptions should be examined to ensure that it handles Alpha AXP hardware exceptions similarly For example consider a case in which an exception handler has been written to handle an access violation You may expect different behavior upon normal completion of the handler In this case the handler should always perform a nonlocal GOTO to exit the handler so that program execution continues in a predictable way Note also that exceptions on the Alpha AXP hardware are imprecise and therefore are not always restartable Digital recommends using a non local goto to achieve consistent behavior across both PL I platforms Fixed decimal precision differences between DEC PL I and VAX PL I The precision specified for a PL I fixed decimal data type must be in the range of 1 to 31 for DEC PL I VAX PL I allows a fixed point decimal variable to be declared with a precision of zero and also allows built in functions to specify a fixed decimal precision of zero DEC PL I does not allow zero to be used in either of these situations and issues an error FlXDPRECZERO when the precision specified for a fixed decimal is zero Differences in behavior between OpenVMS VAX and OpenVMS AXP architec
13. whereas the DEC PL I compiler does not Changes for null statements and label behavior in DEC PL I VAX PL I does not compare the multiple labels of many succeeding combinations of labels and null statements so that they have the same address However DEC PL I optimizes these label null statement sequences and compares the multiple labels so that they result in the same address The following example illustrates this difference PROC options main IF A C THEN PUT LIST NULL STATEMENT LABELS COMPARE EQUAL FOR DEC PL I ELSE PUT LIST NULL STATEMENT LABELS COMPARE NOT EQUAL FOR VAX PL I D IF C D THEN PUT LIST ERROR THESE LABELS SHOULD NEVER COMPARE EQUAL END 16 Null statement Null statement Null statement In DEC PL I you can continue when a GOTO statement with the OTHERWISE option is used to go to an undefined label array element within a BEGIN END block VAX PL I does not support this function The following example works with DEC PL I but not VAX PL I program procedure options main dcl i fixed binary 31 0 begin Preface i 2 goto part i otherwise put skip list At continue end part 1 end program e Run time exception handling is more consistent when processing formats of GET EDITs and PUT EDITs in DEC PL I than it is in VAX PL I If DEC PL I encounters an exception when processing a format such as PLI INVFMTPARM a sign
14. 1 Overview of Changes from VAX PL I In addition to the new features outlined above DEC PL I Version 4 0 contains the following changes from the VAX PL I Version 3 5 product Changes to correct VAX PL I Version 3 5 errors A secondary objective of this release is correction of VAX PL I Version 3 5 errors A number of problems with Version 3 5 have been corrected Some of these were documented in the Version 3 5 release notes while others were discovered after the release of Version 3 5 Changes in virtual memory requirements The virtual memory requirements for DEC PL I may be extensive depending to the type of PL I language constructs that you use Processing the PUT and GET statements BEGIN blocks and PROCEDURE blocks with the DEC PL I compiler tend to require more virtual memory than the same operation would if you were using the VAX PL I compiler Heavy usage of these constructs in your programs may exhaust your user limits for virtual memory The typical compiler errors that you receive are SPLIG F TEXT Compiler abort virtual memory limits exceeded SSYSTEM F ABORT abort SLIB F INSVIRMEM insufficient virtual memory You can recover by increasing your user page file quota PGFLQUOTA See the Kednos PL I for OpenVMS Alpha Installation Guide or the OpenVMS System Manager s Manual for more information on increasing your user page file quota Changes in behavior for calls to bound procedures With VAX PL I nested procedure
15. C PL I for OpenVMS AXP Version 4 0 states that the version of the OpenVMS AXP operating system for DEC PL I is OpenVMS AXP Version 1 5 or higher This is incorrect The correct information is OpenVMS AXP Version 1 5 Information in Section D 2 Differences Between VAX PL I and DEC PL I is more current in Section 11 of these release notes PL I for OpenVMS Systems User Guide 27 Preface Figures 10 6 and 11 1 are true for the OpenVMS VAX operating system but not for the OpenVMS AXP operating system as the manual states Please see the OpenVMS Calling Standard manual order number AA PV69A for the equivalent OpenVMS AXP information The Calling Standard manual is a component of the Programmer s Kit in the OpenVMS AXP documentation set Example 10 8 is true for OpenVMS VAX only as the manual states The OpenVMS AXP equivalent is as follows Example 1 Displaying Arguments Passed to a Condition Handler AXP INCLUDE CHFDEF 1 DECLARE X FIXED CHF ARGPTR ONARGSLIST 2 Output number of signal arguments PUT SKIP LIST Signal Arg Count CHF SIG_ARGS Output condition name argument and rest of signal arguments PUT SKIP LIST Condition name CHF SIG_NAME PUT SKIP LIST DIM CHF SIG_ARG 1 additional arguments 5 DO X 1 TO DIM CHF SIG_ARG 1 PUT SKIP LIST CHF SIG_ARG X END Output RO and R1 PUT SKIP 2 LIST Low Order 32 bits RO CHFSIL_MCH SAVRO_LOW O
16. CB argument generated using VAXCONDITION PLI ENDPAGE This resulted in an access violation in the RTL This problem has been corrected in the DEC PL I Run Time Library 49 QAR 01808 The DEC PL A PLI STARTLET TLB did not define TPUDEF and NSADEF include modules correctly This problem has been corrected in the DEC PL I PLISSTARTLET TLB text library 51 QAR 1809 The BIT builtin produced unexpected result when the argument was neither a string expression nor an arithmetic expression in nonliteral form This problem has been corrected in the DEC PL I compiler 54 QAR2602 The DEC PL I program using an indexed READ would fail with a record not found error This problem has been corrected in the DEC PL I Run Time Library 71 Null bytes throwing off string results in DEC PLA This problem has been corrected in the DEC PL I Run Time Library 74 CF S 25858 Picture variables could not be output using the F w PUT EDIT format item This problem has been corrected in the DEC PL I Run Time Library 76 CF S 26116 The DEC PL I RTL routine which is called to establish a condition handler when an ON statement is executed was not properly handling its data to allow for AST reentrancy If an ON statement was interrupted and another ON statement was then executed at AST level an access violation might result Preface This problem has been corrected in the DEC PL I Run Time Library 78 CF S 25914 AREA condit
17. Kednos PL I for OpenVMS Alphatm Release Notes for Version 4 4B and Runtime Library Version 4 4B This manual provides release information on Kednos PL I Version 4 4B for OpenVMS Alpha a software language and the associated Runtime Library Version 4 4B Revision Update Information This is a new manual Operating System and Version For Kednos PL I for OpenVMS Alpha OpenVMS Alpha Version 6 2 or higher Software Version Kednos PL I Version 4 4 for OpenVMS Alpha Published by Kednos Corporation Pebble Beach CA www Kednos com May 2004 Kednos Corporation makes no representations that the use of its products in the manner described in this publication will not infringe on existing or future patent rights nor do the descriptions contained in this publication imply the granting of licenses to make use or sell equipment or software in accordance with the description Possession use or copying of the software described in this publication is authorized only pursuant to a valid written license from Kednos Corporation or an anthorized sublicensor No responsibility is assumed for the use or reliability of software on equipment that is not listed as supported in the Product Description Copyright Kednos Corporation 1980 2004 All rights reserved Copyright 1980 2004 The following are trademarks of Hewlett Packard Company Alpha AXP DEC DECnet DECtalk DECUS Digital IVP MicroVAX OpenVMS RMS RMS 11 RX50 TK50 VAX
18. al is raised If the exception is handled then processing continues with the next format item regardless of the nature of the signal and the format item that was being processed when the exception was detected This is not always the case with VAX PL I This holds true for conversion errors as well With VAX PL I some conversions with GET EDIT would raise the CONVERSION condition while others would raise the ERROR condition with ONCODE PLI _CNVERR DEC PL I uniformly raises CONVERSION when data cannot be converted The following example demonstrates this difference cnverr proc options main include plidef declare srcstring character 10 initial 4 4445 temp fixed bin 31 on error begin if oncode pli _cnverr then put skip list VAX PL I detects CNVERR not restartable if oncode pli _oncnvpos then put skip list DEC PL I detects ONCNVPOS restartable goto done end get string srcstring edit temp b3 6 done end cnverr e Nonlocal returns work properly under DEC PL I A nonlocal return is a RETURN statement that is lexically nested between any number of BEGIN END pairs for example 17 Preface nested_proc proc returns fixed begin begin begin begin begin return 5 end put skip list shouldnt be here 1 end put skip list shouldnt be here 2 end put skip list shouldnt be here 3 end put skip list shouldnt be here 4
19. ation the compiler uses the value of the last found initialization as the value for the static variable Preface In DEC PL I you cannot depend on the value of the last found initialization being assigned to the static variable This behavior may cause a change in behavior for PL I external variable initializations If a PL I external variable is dedared with the attributes EXTERNAL STATIC INITIAL all blocks that declare the variable MUST be initialized with the same value Because VAX PL I allowed overlapping static storage initialization you could specify different initial values for the SAME external variable within containing blocks The last initial value encountered by the VAX PL I compiler was the value of the external variable In DEC PL I this rule is more strictly enforced if the user specifies an initial value in the declaration of a PL I external variable the same initial value declaration must be specified at each occurrence of the declaration of the external variable in all blocks that declare the external variable Failure to do so can cause unpredictable results The following examples illustrate correct and incorrect declarations Correct Declaration of an External Variable Initialization program proc options main dcl test fixed external initial 5 Pp proc dcl test external initial 5 The value of this variable should be 5 put skip list The value of test is gt test end end Inco
20. converted to a PL I fixed binary data item with a precision 31 and a scale factor of 30 FIXED BINARY 31 30 On OpenVMS VAX this overflow situation results in two overflow conditions being raised On OpenVMS AXP this situation results in one overflow condition being raised Note that all VAX PL I cases of overflow are detected on OpenVMS AXP in the program In the example DEC PL I detects one overflow for the two overflows reported by VAX PL I This difference is due toa difference in the instruction set between and AXP The example illustrates two occurrences of this situation In each case the fixed decimal item is converted to fixed binary item by a Series of three steps as follows 1 Multiplies the fixed decimal 31 21 item by the decimal representation of 2 30 2 Shifts the fixed decimal 31 51 created by step 1 to the right by 21 3 Converts the fixed decimal 31 30 created by step 2 to a fixed binary item 31 30 The OpenVMS VAX macro instructions output by VAX PL I to perform this conversion are as follows fixb30 fixd21 10 PLI B_PAC_2 POWER_30 31 60 fp 31 96 fp 21 31 96 fp 0 31 112 fp 31 112 fp r4 r4 80 fp In example during the execution of the OpenVMS VAX mulp instruction and during the OpenVMS VAX cvtpl instruction overflows occur The OpenVMS AXP instruction set does not contain decimal instructions Therefore OpenVMS VAX emulates decimal instructions by means of a ser
21. d in chapter 3 of the reference manual Section 3 4 3 contains the following statement PL I allocates storage for an aligned bit string variable on a byte boundary and reserves an integral number of bytes to contain the variable This is true for the default packed alignment The following has been added to the documentation If natural alignment is in effect PL I allocates storage for an aligned bit string variable on a longword boundary and reserves an integral number of longwords to contain the variable See the user manual for information on the ALIGN and DATA command line qualifiers which affect what type of alignment is in effect The last paragraph of section 3 2 4 of the reference manual contained values for T_floating data in the range 2 225073859D 380 to 1 797693135D308 The letter D in both of these numbers is invalid and should be E 9 Overview of Changes Made in Version 4 0A DEC PL I Version 4 0A contains fixes to problems reported in DEC PL I Version 4 0 3 CF S 19308 A run time error is signaled when SKIP 0 is used as an output control format item in a PUT EDIT statement This problem has been corrected in the DEC PL I Run Time Library 5 CF S 19740 A PUT SKIP before a line written to a PL I PRINT file is ignored when that line is followed by a PUT PAGE This problem has been corrected in the DEC PL I Run Time Library 11 CF S 11603 A PLI update or install will fail if there is a customer command
22. ecific GOTO statement prior to the GOTO statement the compiler bugchecks An example of a program with such a construct follows 23 Preface 24 program procedure options main dcl i fixed binary 31 0 part 1 i 2 goto part i otherwise end program To avoid this error place the label references for a specific OTHERWISE option after the GOTO statement e CHARACTER Stack Usage Temporary stack space allocated for return values from routines returning CHARACTER is not deallocated until the calling routine exits The restriction is related to determining the lifetime of the temporary value A sample code segment displaying this restriction follows DO I 1 TO 1000 CHARACTER_STRING ROUTINE _RETURNING_CHAR_STAR END In this situation the temporary storage for the return value is not deallocated until the calling routine exits which results in considerable stack usage A means of avoiding this restriction is to enclose the use of the routine in a BEGIN block For example DO I 1 TO 1000 BEGIN CHARACTER_STRING ROUTINE _RETURNING_CHAR_STAR END END Although this method is slightly more CPU intensive because of the extra CALL RETURN sequence it causes the stack top to be correctly reset between each iteration of the loop e Silent underflow during compilation The compiler silently replaces an underflowing floating point constant with 0 0 during compilations e Descriptors for pictu
23. ersion of the documentation DEC PL I Version 4 0 The VAX PL I Version 3 5 user manual said on page 2 13 that all Error and Warning error messages are counted toward the error limit VAX PL I and DEC PL I do not count Warning messages only Error messages toward the error limit The PL I Reference Manual for VAX VMS and RISC ULTRIX contained an error on the description of the LTRIM and RTRIM built in functions The definition in that manual for LTRIM s b states that LTRIM removes blanks from the left of string s or if b is supplied removes string b from the left of string s The correct definition of LTRIM s b is that LTRIM removes white space from the left of string s or if b is supplied removes string b from the left of string s The definition in the manual of RTRIM s b states that RTRIM removes blanks from the right of string s or if b is supplied removes string b from the right of string s The correct definition of RTRIM s b is that RTRIM removes white space from the right of string s or if b is supplied removes string b from the right of string s White space characters are defined as blank tab newline carriage return vertical tab and formfeed Preface 12 Known Problems and Restrictions With Version 4 1 This section describes known problems with DEC PL I Version 4 1 and known ways to avoid the problems Problem Array bounds violations are not detected at run time even with CHECK enabled Workaround
24. g new OpenVMS V6 2 routines SYS PERSONA_ASSUME SYS PERSONA_CREATE SYS PERSONA_DELETE These problems were fixed by the updates to make PLI STARLET TLB compatible with VMS V7 0 e DECPLI40A 548 With a particular combination of area size and allocation sizes it was possible for a second ALLOCATE in an area to corrupt the contents of the memory obtained by the first ALLOCATE in that area This problem has been corrected in the DEC PL I Compiler e DECPLI40A 548 Nonlocal GOTO statements did not unwind properly when compiled with optimizations This problem has been corrected in the DEC PL I compiler e DECPLI40A 837 A conversion problem occurred in a GET EDIT statement with the STRING option when zero was specified in the input string as follows TEST PROCEDURE OPTIONS MAIN DCL FixedVar FIXED GET STRING 00 EDIT FixedVar P V99 END TEST This problem has been corrected in the DEC PL I Compiler e DECPLI40A 981 Repeatedly opening and closing an indexed file declared as KEYED and opened for INPUT resulted in a memory leak Preface This problem has been corrected in the DEC PL I Runtime 8 1 Corrected Documentation Errors The errors in this section have been corrected in the current version of the documentation DEC PL I Version 4 1 DECPLI40A 847 The reference manual did not mention the alternative of natural alignment when discussing storage allocation This is correcte
25. gram shows P procedure options main call pl 5 end pl procedure size_chv dcl size_chv fixed binary dcl strvl character size_chv varying init sksks strvl abcde end 10 Preface In addition on OpenVMS AXP if a string has run time bounds the debugger examines and deposits to the variable as if it is a nonvarying string The work around is to use the debug command EXAMINE ASCIW e Label array variables e Label constants e Entry variables and label variables e Structure parameter variables of unknown size specifically PL I structure parameters declared with star extents or members with unknown size are not fully supported e PL I external controlled defined and based variables for example you cannot examine the externally declared PL I based variable pli_based_nofp shown in the following sample program dcl pli_globaldef fixed binary 31 globaldef dcl pli_based_nofp fixed binary 31 based addr pli_globaldef p procedure options main end e Differences in behavior between VAX PL I and DEC PL I that involve unreferenced static variables unreferenced globaldef variables unreferenced internal static variables and unreferenced automatic variables e Referenced PL I REPLACE floating point constants e PLA REFER structures across all data types e Depositing to PL I bit string variables using the B format DBG gt DEPOSIT BIT 111 B The workaround is to depo
26. has been corrected whereby a program which did output to a disk file including SYS OUTPUT in batch might omit the last line of output Overview of Changes Made in Version 4 4 and Runtime Library Version 4 3 Kednos PL I Version 4 4 and Runtime Library Version 4 3 contain the following enhancements and fixes e The product name has been changed to Kednos PL I for OpenVMS Alpha e A defect has been corrected whereby compilation of a program with a large amount of static data would fail with the error PLIG F ASSERTION Handler context data is allocated at a negative offset e A defect has been corrected whereby text output of G floating and T floating data was restricted to the range of D floating variables e A defect has been corrected whereby compiling the SCREEN PLI module from the PHONE sample application would fail with the error PLIG F ASSERTION GEM_GX_ENUMERATE initial set empty for e A defect has been corrected whereby certain programs from the IVP which happened to not have condition handlers at the outermost routine would hang when any condition was signalled e A defect has been corrected whereby compiling certain modules DEBUG would fail with the error PLIG F BUGCHECK Compiler bug check during translation Preface After J une 2004 a separate Hobbyist license from Kednos will be required beyond simply having the OpenVMS Hobbyist license from HP Overview of Changes Made in Version 4 3 and Runtime Libra
27. ies of OpenVMS AXP instructions and OTS calls During the instructions to emulate the OpenVMS VAX mulp instruction an overflow is correctly detected During the instructions to convert packed decimal data to integer data an overflow is not detected Preface Note that after a fixed overflow condition has been raised the value resulting from an operation that causes this condition is undefined In this case the value from the result of the multiplication that caused the overflow is undefined When it is used in an expression no guarantee exists that an overflow will be raised again This happens when the result of the overflow is shifted to the right and then converted from decimal to integer In this case it is reasonable to expect a difference in the number of overflows detected from one PL I statement Due to the difference between OpenVMS VAX and OpenVMS AXP instructions this situation cannot be prevented In general on a per statement basis DEC PL I detects overflow but the number of overflows it detects per statement is not guaranteed to be the same on OpenVMS VAX and OpenVMS AXP The following complete example illustrates the difference program procedure options main dcl fixb30 fixed bin 31 30 dcl fixd18 fixed decimal 31 18 dcl fixd21 fixed decimal 31 21 dcl fixd22 fixed decimal 31 22 dcl fixd24 fixed decimal 31 24 on fixedoverflow begin put skip list fixed overflow occurred end fixd18
28. ion not being signaled properly when area was fragmented This problem has been corrected in the DEC PL I Run Time Library 82 CF S 26326 DELETE FILE statement which is made towards a non existent record was causing two signals to be raised This problem has been corrected in the DEC PL I Run Time Library 84 CF S 26323 In a READ FILE statement the KEY is was not being correctly handled if it was PICTURE data type causing the READ to fail This problem has been corrected in the DEC PL I Run Time Library 92 CF S 26832 The DEC PL I compiler was generating incorrect code for select expressions using fixed bin 7 variables when an overflow took place This problem has been corrected in the DEC PL I compiler 93 CF S 26965 A REWRITE FILE statement failed if it was the last record of a sequential file This problem has been corrected in the DEC PL I Run Time Library 99 CF S 23922 The index builtin was returning wrong results when byte 0 occurred in the string This problem has been corrected in the DEC PL I Run Time Library 134 CF S 28745 DEC PL I SYSPRINT was ignoring the PAGESIZE n option of the OPEN statement This problem has been corrected in the DEC PL I Run Time Library 225 CF S 30137 The DEC PL I compiler was failing to properly record the original picture string and causing a compiler abort when debug was used This problem has been corrected in the DEC PL I compiler 243 CF S 30808
29. ion of 15 has been supplied at line number 3 in file tdisk tdir t pli 1 declare h float binary 113 SPLIG W FLTBPREC The precision specified for H exceeds the implementation s limit of FLOAT BINARY 53 The maximum precision of 53 has been supplied at line number 2 in file tdisk tdir t pli 1 PLIG I SUMMARY Completed with 0 errors 2 warnings and 0 informational messages e Before VAX PL I Version 3 5 certain G and H floating values could improperly be truncated when they were converted to either a fixed decimal or pictured datatype Even when the PLI command line does not include the G_FLOAT qualifier and the program does not include floating point variables large enough to require H float the VAX PL I Version 3 5 compiler can generate code that uses H floating data when intermediate calculations require higher precision in order to produce correct results OpenVMS AXP PL I Version 4 0A does not support a floating point data type with a precision higher than 53 the maximum value of the G floating point data type Therefore certain conversion operations performed by DEC PL I may produce results that are truncated in comparison to the results produced by VAX PL I 10 4 Support for Other Language Elements In DEC PL I Version 4 0A the format of the ONARGSLIST built in function is identical to that of VAX PL I However the data structure pointed to by the mechanism array pointer is different 12 Preface 1
30. n The compilers should issue the following message in both cases SPLIG E INVSTAREXT An asterisk is not a valid subscript or argument The following example is a sample of the code to which the compilers respond incorrectly p procedure dcl e entry fixed call e reference end e The DEC PL I and VAX PL I compilers bugcheck if you use an asterisk as a label array subscript if the variable you use as a subscript for a label array in a GOTO statement is not declared and if a corresponding label array indudes an asterisk The following PL I program illustrates the problem bug procedure goto casel x casel 1 casel end Instead declare the variable explicitly e The DEC PL I compiler sometimes generates an incomplete informational message for PL I structure variables that are self referencing The compiler generates the message when you use the DEBUG OPTIMIZE qualifiers The following PL I program illustrates the problem program PROCEDURE DCL A_CURDB EXTERNAL POINTER DCL 1 DBCMN BASED A_CURDB 2 DBTMAX FIXED BIN 15 DCL LEAF_PTR PTR DCL 1 LEAF BASED LEAF PTR 2 LEAF_COUNT FIXED BIN 15 2 ENTRY LEAF LEAF COUNT 3 KEY FIXED BIN 15 END PROGRAM 26 Preface The message that you receive does not contain the name of the noninitialized fetch In this case it is LEAF LEAF_COUNT The message that you receive is END PROGRAM a SPLIG I UNINIT variable
31. nstall the compressed version during installation you can decompress it later using the following command LIBRARY DATA EXPAND OUTPUT SYSSCOMMON SYSLIB _ SYSSCOMMON SYSLIB PLISSTARLET TLB The decompressed form of the library is slightly over twice the size of the compressed version Details of Changes Made in Version 4 1 DEC PL I Version 4 1 contains fixes to problems reported in DEC PL I Version 4 0A e DECPLI40A 69 Performance of ON conditions was slower on AXP than on VMS Condition handling support has been redesigned to make better use of Alpha architectural features This results in improved runtime performance This problem has been corrected in the DEC PL I Compiler e DECPLI40A 72 Preface The DEC PL I compiler was failing to properly parse a GET LIST statement when the target variable contained multiple commas for example stringvalue XXX rPrrrvreredg d r GET STRING stringvalue LIST cv1 cv2 cv3 cv4 cv5 cv6 cv7 where cv1 cv7 are CHARACTER n VARYING stringvalue XXX 3 GET STRING stringvalue LIST cv1 cv2 cv3 cv4 cv5 cv6 cv7 where cv1 cv7 are CHARACTER n VARYING This problem has been corrected in the DEC PL I Compiler e DECPLI40A 77 DECPLI40A 336 Previously the following symbols of the NSADEF module were not available in the SYS LIBRARY PLI STARLET TLB NSA EVENT_TYPE NSA EVENT_SUBTYPE PLI STARLET TLB was also missing the definitions for the followin
32. options main dcl 1 tmpl1 based 2 tmp2 fixed 2 tmp 20 bit 17 refer tmp2 2 tmp3 fixed dcl mptr mptr2 pointer dcl tmp4 4 bit 10 based allocate tmpl set mptr allocate tmp4 set mptr2 mptr gt tmp2 17 mptr gt tmp3 15 mptr gt tmp1l tmp 10000000001000010 b does not work put skip list mptr gt tmp1 mptr2 gt tmp4 1000000000 b does not work put skip list mptr2 gt tmp4 end The error message received is SPLIG E INVSTAREXT An asterisk is not a valid subscript or argument The alternative is to initialize the array by means of a DO loop e VAX PL I and DEC PL I compilers bugcheck when trying to pass an asterisk as an argument using the REFERENCE or VALUE built in functions BIFs The problem is caused by a function added to Version 3 5 which allows you to use asterisk subscripts when referencing an entire array The compilers report the following error SPLIG E INVSTAREXT An asterisk is not a valid subscript or argument 25 Preface Also if the asterisk is passed directly as an argument without using the BIFs the compilers issue an incorrect error message SPLIG E TOOFEWARG Entity has been referenced with too few arguments If you pass the asterisk using the DESCRIPTOR built in function the compilers again issue the wrong error message as follows SPLIG E DESCRIBIF Invalid use of the DESCRIPTOR built in functio
33. re variables Picture variables are always passed incorrectly by class NRO descriptors regardless of the format of the picture variable This problem may be addressed in a future release of DEC PL I e The compiler can now handle records up to 32K which is the RMS maximum After a file is opened a buffer equal to the longest record length is allocated This buffer is then used when the record is read This change is highly dependent on obtaining the longest record length value for a file from RMS using the xab w_Irl field of fhc_xab block when the file is opened However rare cases exist in which RMS fails to provide a correct value in that field If this occurs the compiler issues the error message PLIG F READERR which is followed by the operating system message RMS F USZ invalid user buffer size Preface One alternative is to edit the source file and write out a new version causing RMS to update the Irl value in the file header The compiler issues the error message LOCNEED when the SIZE function references a based variable declared without an associated pointer For example TEST PROC OPTIONS MAIN DCL 1 RECORD BASED 3 ITEM1 CHAR 10 3 ITEM2 CHAR 20 PUT EDIT SIZE RECORD F 5 PLI E LOCNEED END e The compiler issues an incorrect error message when initializing an array through a pointer using an asterisk as an array subscript The following example illustrates the problem test procedure
34. rements described for the SYS PUTMSG procedure This procedure is described in the Introduction to the VMS Run Time Library On pages 2 7 and 2 11 in Section 2 32 the user manual incorrectly states that the DIAGNOSTICS qualifier to the PLI command is for the OpenVMS VAX operating system only This qualifier operates on both OpenVMS VAX and OpenVMS AXP 29
35. rrect Declaration of an External Variable Initialization program proc options main The initialization MUST be the same for all declarations of the external variable dcl test fixed external initial 5 dcl test1 fixed external initial 5 dcl test2 fixed external p proc The initialization MUST be the same for all declarations of the external variable dcl test external initial 6 dcl testl1 external dcl test2 external initial 6 The value of these variables is unpredictable 15 Preface aed put skip put skip put skip end end Note list The value of test is gt test list The value of testl is gt testl list The value of test2 is gt test2 As no guarantee exists as to which occurrence of the external variable the DEC PL I compiler processes first each occurrence of the variable must contain the same initial value Changes in behavior for the SUBSTR built in function In PL I the SUBSTR function is defined only when the position attribute the integer expression that indicates the position of the first bit or character in the substring is greater than or equal to 1 If the position attribute is less than 1 that is the SUBSTR BIF is undefined you may observe different results with DEC PL I than with VAX PL I Changes in underflow detection behavior for DEC PL I The VAX PL I compiler outputs underflow detection code
36. ry Version 4 2 DEC PL I Version 4 3 and Runtime Library Version 4 2 contain the following enhancements and fixes The VMS Hobbyist license is now supported Storage allocations of PICTURE types is corrected Comma delimited fields in GET STRING have been fixed Nested INCLUDE statements are now correctly supported To move a DEC PL I program to another system where PL I is not installed you will need to install a separate DPLI RTLSHR kit which is not delivered as part of OpenVMS Overview of Changes Made in Version 4 2 DEC PL I Version 4 2 contains the following enhancements and fixes Performance of operations on BIT 1 data has been enhanced to use in line operations instead of making more expensive calls to OTS routines The PL I compiler and the PL I System Interface Library PLISSTARLET TLB have been modified to support use of the ALIGNED command line qualifier with this library Since this corrents a structure layout problem if you use the ALIGNED command line qualifier you should recompile all sources with the PL I 4 2 compiler Overview of Changes Made in Version 4 1 DEC PL I Version 4 1 contains the following enhancements and fixes VMS Version 7 0 Support DEC PL I Version 4 1 contains a new runtime that runs on VMS Version 6 2 or higher including VMS Version 7 0 PL I code compiled on prior versions of the product will run on this version However PL I code must be compiled using DEC PL I Version 4 1
37. s can be called by other routines using the PL I language s entry variable However in order to successfully reach these bound procedure routines and ensure proper execution of uplevel referenced variables within the bound procedures the user must keep the parent invocation of the bound procedure active This assures that the stack references to uplevel variables within the bound procedure to the parent s stack which contained the uplevel referenced variables are still valid With DEC PL I the same situation still exists however you may experience different behavior between VAX PL I and DEC PL I if you do not keep the parent invocation active This is due to the fact that bound procedures are not created in the same way by the two compilers DEC PL I creates the bound procedure values on the stack of the parent of the bound procedure The user program may produce an access violation or may exhibit other undefined behavior when the parent invocation of the bound procedure is not kept active Because the stack of the parent has been destroyed the bound procedure code found on the parent stack may also have been destroyed or corrupted and the user may not be able to reach the bound procedure 13 Preface 14 With VAX PL I you may receive the same undefined behavior Cases may exist in which you are able to reach the bound procedure however you may still receive errors in results from the uplevel referenced variables within the bo
38. sit without using the B i e DEPOSIT BIT 111 e Referenced PL I structures declared as globalref No debugger information is output for the structure members e Position attribute for PL I bit string variables 10 3 Differences in VAX PL I and DEC PL I Support for Floating Point Data Types DEC PL I Version 4 0 supports five floating point data types F D G IEEE S and IEEE T float VAX PL I supports four floating point data types F D G and H When you declare a float binary object with a precision greater than 53 which requires the H floating point data type the DEC PL I compiler supplies a precision of 53 the maximum value of the G floating point data type When you declare a float decimal object with a precision greater than 15 which requires the H floating point data type the DEC PL I compiler supplies a precision of 15 the maximum value of the G floating point data type 11 Preface e DEC PL I may produce truncated results when higher precision values are specified The following PL I program shows the output from DEC PL I when precision values exceeding the limits are specified P procedure options main dcl h float binary 113 dcl d float decimal 34 end The output received from the DEC PL I compiler for this program is as follows declare d float decimal 34 SPLIG W FLTDPREC The precision specified for D exceeds the implementation s limit of FLOAT DECIMAL 15 The maximum precis
39. to run on VMS Version 7 0 or higher The PL I System Interface Library PLISSTARLET TLB has been rebuilt to run on VMS Version 6 2 or higher including VMS Version 7 0 Condition Handler mprovements 7 7 1 7 2 8 Preface Performance of condition handlers has been enhanced See the Details of Changes Made in Version 4 1 section for details e Miscellaneous Fixes See the Details of Changes Made in Version 4 1 section for details Installation Information Kit Information This section describes changes to the installation procedure Please read this section carefully prior to installing DEC PLA The DPLI041 kit supplies the DEC PL I Run Time Library RTL to allow correct linking of programs compiled with DEC PL I The RTL will be installed if you do not have one or if the copy on your system is older than the copy on this kit Compression of the PL I System Interface Library PLISSTARLET TLB Beginning with VAX PL I Version 2 3 for OpenVMS VAX the system interface library PLISSTARLET TLB has been shipped in compressed library format which reduces the amount of space required to store the library but increases the amount of time required to access and retrieve a component of the library such as a system service declaration If you use PLISSTARLET TLB frequently and you have disk space available you may want to decompress the library during the installation when you have the opportunity to do so If you choose to i
40. tures regarding PL I overflow conditions In general any PL I operation that overflows on OpenVMS VAX also overflows on OpenVMS AXP Since the Alpha AXP hardware does not include support for packed decimal instructions that correspond to the PL I FIXED DECIMAL datatype data items of this type are handled on OpenVMS AXP by run time calls to either the DEC PL I Run Time Library routines or system Object Time System OTS routines These emulation routines perform many operations to compute the result of a FIXED DECIMAL operation which in most cases can be done with a single VAX instruction Many emulation operations generate an overflow Therefore DEC PL I guarantees at least one overflow on OpenVMS AXP for every overflow on OpenVMS VAX per PL I statement DEC PL I cannot guarantee that the resulting behavior or value produced by a PL I statement that produces an overflow condition is the same value or behavior as it is on VAX PL I 19 Preface 20 23 0125 0132 013C 0141 23 0125 0132 013C 0141 mulp ashp cvtpl movl mulp ashp cvtpl movl The following example illustrates a difference in overflow detection between VAX PL I and DEC PL I fixb30 fixd21 10 PLI B_PAC_2_POWER_30 31 60 fp 31 96 fp 21 31 96 fp 0 31 112 fp 31 112 fp r4 r4 80 fp The difference occurs when a PL I fixed decimal data item with a precision of 31 and a scale factor of 21 FIXED DECIMAL 31 21 is
41. und procedure This is because the bound procedure code on the parents stack may have been corrupted The following example shows behavior where the bound procedure entry6a cannot be reached by DEC PL I because the parent procedure entry6 has exited and its stack is free to be recovered and used by other procedures Therefore the bound procedure code has been destroyed Note that this programs also fails with VAX PL I However it fails after having reached the bound procedure entry6a and while trying to access the uplevel referenced variables from the parent entry6 Example of Bound Procedure Failure Behavior If Parent Bound Procedure is Inactive program proc options main program proc options main dcl ent2 entry variable dcl fne entry returns entry variable dcl evar char 25 var init fnc entry6 ent2 fnc call destroy_stack call ent2 ut skip list Evar is gt evar P P entry6 proc returns entry return entry6a entry6a proc evar evar entry6a return end entry6a end entry6 destroy _stack proc Declare enough space to destroy previous stack values before this call dcl temp_space char 1000 temp_space hello end end program e Changes in behavior for overlapping static storage initialization In VAX PL I and DEC PL I overlapping initialization of static storage is not supported When VAX PL I finds an overlapping static initializ
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