IV89819: INVALID DWARF DW_AT_LOCATION ATTRIBUTE CAUSING DBX "ASSERTION FAILED AT LINE 1669" ERROR

XL C/C++ for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C/C++ for AIX Fix Pack 21 (January 2019 Update) for 12.1

APAR status

• Closed as program error.

Error description

• When compiling code using DWARF debug information via -g
  -qdbgfmt=dwarf , the generated DWARF information contains an
  invalid value for a DW_AT_location attribute.  This invalid
  value may cause errors when attempting to debug the code with a
  debugger that supports DWARF, such as DBX.
  
  Dumping the DWARF information from a problem object file may
  show the invalid DW_AT_location value similar to:
  
  <4><37545>      DW_TAG_variable
                  DW_AT_location          DW_OP_bregx4292870144+0
                  DW_AT_name              _St
                  DW_AT_decl_file         1
                  DW_AT_decl_line         0
                  DW_AT_type              <15459>
  
  A valid DW_AT_location value would look similar to:
  
                  DW_AT_location          DW_OP_fbreg 144
  
  
  
     === EXAMPLE ===
  
  $ xlC test.cpp -g -qdbgfmt=dwarf
  $ dbx a.out
  Type 'help' for help.
  reading symbolic information ...
  internal error: assertion failed at line 1669 in file
  dwarf_read.c
  (dbx)
  

Local fix

Problem summary

• USERS AFFECTED:
  Users of dwarf debug format may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  The compiler was generating invalid debug information causing
  an internal error.
  

Problem conclusion

• The compiler issue has been resolved.
  

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:

  IV91643 IV91677 IV97574

Fix information

• Fixed component name

  XL C/C++ FOR AI

• Fixed component ID

  5725C7200

Applicable component levels

• RC10 PSY

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