LI77247: INCORRECT DEBUG INFORMATION CORRUPTS DEBUGGER

XL C/C++ for Blue Gene/Q Fix Pack 12 (May 2015 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 14 (May 2016 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 15 (October 2017 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 5 (August 2013 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 6 (November 2013 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 7 (February 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 8 (May 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 9 (August 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 10 (November 2014 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 11 (February 2015 Update) for 12.1
XL C/C++ for Blue Gene/Q Fix Pack 13 (August 2015 Update) for 12.1

APAR status

• Closed as program error.

Error description

• 12.1.0.2 PTF for XL C/C++ for BG/Q compiler generates the
  following  debug information and crashes debugger.
  <cd>   DW_AT_artificial  : 1
  <ce>   DW_AT_external    : 1
  <cf>   DW_AT_frame_base  : 1 byte block: 6f
  (DW_OP_reg31)
  <d1>   DW_AT_type        : 0x0 0x199
  <d9>   DW_AT_MIPS_linkage_name: _ZN6<nevermind>_
  These DWARF attributes are invalid according to the DWARF
  specification.
  Issue was only seen with -qsmp=noopt option.
  

Local fix

• Use 12.1.0.1 PTF or remove -qsmp=noopt option.
  

Problem summary

• PROBLEM DESCRIPTION: Incorrect debug information crashing
  Totalview debugger
  
  USERS AFFECTED: BG/Q compiler users compiling invoking high
  level optimizer component.
  

Problem conclusion

• CONCLUSION: Uninitialized value for the block id is causing the
  compiler to emit bad debug opcodes.  This bad wcode is also
  causing the compiler to generate bad debug info and crashing
  the debugger.
  The fix is to initialize this value to 0 in the construction of
  generating REC opcodes.
  

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

  XL C/C++ FOR BG

• Fixed component ID

  5799AG100

Applicable component levels