PK97320: PACK and UNPK assembler instruction syntax errors in LPEX editor

APAR status

• Closed as program error.

Error description

• Receiving errors on the PACK and UNPK instructions in the LPEX
  editor when editing Assembler source files.
  
  I noted the following errors in the LPEX editor for assembler
  PACK and UNPK assembler instructions.
  
  The following examples have been in production for many years
  and do work as expected but for some reason the LPEX editor
  does not like them.
  
  
  MIDTRERR EQU   *
           MVC   MESSAGE,MIDMSG1              MOVE DD NAME TO MSG
           MVC   MESSAGE+44(8),DD4MIDT        MOVE DD NAME TO MSG
           UNPK  MESSAGE+31(7),EIBRESP        UNPK EIBRESP TO MSG
           MVC   MESSAGE+38(1),EIBRESP+3      .
           NC    MESSAGE+31(8),ZEROFOXS       .
           TR    MESSAGE+31(8),HEXCHARS       MAKE DISPLAYABLE
           UNPK  MESSAGE+59(16),WRKACCT       UNPK ACCT TO MSG
  
  Syntax: UNPK D1(L1,B1),D2(L2,B2).
  
  Error:  Incorrect operand: MESSAGE+59(16).
  
  DOORBV   DS    0H
                                                           INT201
           CLI   BIT102L,X'00'          DID WE GET A CPN?
                                                           INT201
           BNH   DORETURN               NO, WERE DONE
                                                           RST404
           MVI   J2CPNIND,C'1'          SET CPN INDICATOR TO 1
                                                           INT201
           PACK  J2ORIGAC,BIT102F(16)   MOVE BIT102 TO ORIGACCT
                                                          INT201
  Syntax: PACK D1(L1,B1),D2(L2,B2).
  
  Error:  Incorrect operand: BIT102F(16).
  
  
  According to our IBM documentation 16 is a valid operand length
  for the instructions.
  
  It seems some valid statements are being flagged as errors.
  Client is using the PACK and UNPACK instructions with an offset
  and length.
  When he specifies a length of 16 (double word), the statement
  is flagged as an error.  If he changes it to a value less than
  16 (such as 15), the error goes away.
  
  Explaination:
  
  The assembler parser is not handling machine instructions which
  have parameters whose format is D1(L1,B1).
  
  This is a valid bug, which has existed since the parser was
  created.
  UNPK and PACK are only two examples, this bug affects all
  instructions which support this type of parameter.
  
  So for now, a fix could be provided in next release after
  RDz 7.5.
  

Local fix

Problem summary

• Machine instructions which specified a length of 16 caused the
  syntax checker in System z LPEX to produce an error.
  For example the following statement:
  UNPK  MESSAGE+59(16),WRKACCT
  results in the error:
  Syntax: UNPK D1(L1,B1),D2(L2,B2).
  Error:  Incorrect operand: MESSAGE+59(16).
  

Problem conclusion

• The assembler syntax checker was not correctly validating length
  and displacement for machine instructions.
  The problem listed in this APAR has been resolved with
  IBM Rational Developer for System z V7.6.0.1 Fix Pack which
  is available from the Recommended Fixes support download page:
  http://www-1.ibm.com/support/docview.wss?rs=2294&uid=swg27006335
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  RATL DEV FOR SY

• Fixed component ID

  5724T0700

Applicable component levels

• R760 PSY

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