PH43846: ATTRIBUTES OF LITERALS AND ASMA042W MESSAGE INSERT CORRUPTION

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• If conditional assembly code references the length attribute of
  a literal supplied in a variable, for example L'&LIT where &LIT
  contains '=A(1)', but the literal is not previously defined or
  has invalid syntax, message ASMA042W is issued with a corrupted
  insert. Also, if the literal was not previously defined it
  should have been automatically defined by the reference, and
  this also applies to other attributes of literals (apart from
  the Defined attribute).
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of HLASM for z/OS, z/VM, z/VSE and     *
  *                 Linux                                        *
  ****************************************************************
  * PROBLEM DESCRIPTION: ASMA042W insert corrupted and other     *
  *                      problems with attributes of literals    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  1.  A reference in conditional assembly code to the length
      attribute of a previously undefined literal in a variable,
      for example in the form L'&VAR, produced message ASMA042W
      with a corrupted insert.
  
  2.  Since HLASM 1.4, all references to literals, including
      attribute references (apart from the Defined attribute) were
      intended to define the literal, so ASMA042W should not have
      been possible in this case.  However, the implementation did
      not handle conditional assembly attribute references to a
      literal in a variable, for example L'&VAR where &VAR
      contains a literal.
  
      Generating a literal when the only use is for an attribute
      reference is a waste of storage, as the literal is not used.
      It would be better to allow the literal to be defined, but
      to avoid including it in a literal pool in this case.  This
      would also avoid the risk of causing existing programs to
      fail to assemble because of addressability problems caused
      by an increased number of literals after fixing the previous
      omission.
  
  3.  A direct reference to an attribute of a literal in a
      conditional assembly statement (except for the Defined or
      Type attribute) defined the literal at the time that the
      statement was defined, even if that statement was never
      executed.
  
  4.  A reference to an attribute of a literal V-con incorrectly
      incremented the scan pointer past the delimiter at the end
      of the literal.  In open code where the literal was followed
      by two or more spaces, this would appear to work, but the
      literal name would include a trailing space, so it would not
      be commoned up with a direct reference to the same literal.
      In other contexts, this usually failed with message
      ASMA145E.
  

Problem conclusion

• 1.  The insert for message ASMA042W is now corrected, although
      it is no longer needed in the original context.
  
  2.  Any reference to a literal other than the Defined attribute
      now defines the literal and adds it to the symbol table, but
      in the unusual case that there are no references to that
      literal other than attribute references, it is not generated
      in the next literal pool.
  
      If there are literals pending at the end of the program but
      they are all only referenced for attributes, no implicit
      literal pool is generated by the END statement.
  
      This means that a literal which only appears in an attribute
      reference will not be fully evaluated, so for example any
      references to undefined symbols within the literal value
      will not be detected.
  
      A literal containing '*' for the location counter generates
      a unique copy for each statement that references it, as the
      location may be different.  This means that separate
      references to the length attribute and value of a literal
      such as =A(*-START) will actually define two literals, but
      the one for the length attribute will not be generated.
  
  3.  A reference in a conditional assembly statement to an
      attribute (other than the Defined attribute) of a literal
      now defines the literal only when that statement is
      executed.
  
  4.  Processing of an attribute reference to a literal V-con has
      been corrected.
  
  Documentation changes to clarify the processing for attributes
  of literals, as described above, will be included in a future
  update to the publications.
  

Temporary fix

Comments

• ×**** AE23/05/04 FIX IN ERROR. SEE APAR PH54338  FOR DESCRIPTION
  

APAR Information

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

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

  UI79282 UI79283 UI79284

Modules/Macros

•    ASMAINFO ASMA1G   ASMA1M   ASMA1N   ASMA1W
  ASMA12   ASMA15   ASMA16   ASMA2R   ASMA24   ASMA9Z
  

Fix information

• Fixed component name

  HLASM MVS, VM &

• Fixed component ID

  569623400

Applicable component levels

• R160 PSY UI79283

     UP22/02/15 P F202

• R360 PSY UI79282

     UP22/02/14 P 2202

• R689 PSY UI79284

     UP22/02/14 I 1000

Fix is available

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