IBM Support

IV70769: OFFSETOF() NOT CALCULATED CORRECTLY IN DESIGNATED INITIALIZER

Fixes are available

XL C for AIX Fix Pack 12 (May 2015 PTF) for 12.1
XL C/C++ for AIX Fix Pack 12 (May 2015 PTF) for 12.1
XL C/C++ for AIX Fix Pack 4 (July 2015 PTF) for 13.1
XL C/C++ for AIX Fix Pack 13 (August 2015 Update) for 12.1
XL C for AIX Fix Pack 5 (November 2015 Update) for 13.1
XL C/C++ for AIX Fix Pack 5 (November 2015 PTF) for 13.1
XL C/C++ for AIX Fix Pack 14 (December 2015 Update) for 12.1
XL C/C++ for AIX Fix Pack 6 (February 2016 PTF) for 13.1
XL C for AIX Fix Pack 6 (February 2016 Update) for 13.1
XL C for AIX Fix Pack 15 (April 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 15 (April 2016 Update) for 12.1
XL C for AIX Fix Pack 7 (May 2016 Update) for 13.1
XL C/C++ for AIX Fix Pack 7 (May 2016 PTF) for 13.1
XL C for AIX Fix Pack 16 (July 2016 Update) for 12.1
XL C/C++ for AIX Fix Pack 16 (July 2016 Update) for 12.1
XL C for AIX Fix Pack 8 (August 2016 Update) for 13.1
XL C/C++ for AIX Fix Pack 8 (August 2016 PTF) for 13.1
XL C/C++ for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C for AIX Fix Pack 17 (November 2016 Update) for 12.1
XL C for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 18 (February 2017 Update) for 12.1
XL C for AIX Fix Pack 9 (June 2017 Update) for 13.1
XL C/C++ for AIX Fix Pack 9 (June 2017 PTF) for 13.1
XL C for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C/C++ for AIX Fix Pack 19 (August 2017 Update) for 12.1
XL C for AIX Fix Pack 10 (February 2018 Update) for 13.1
XL C/C++ for AIX Fix Pack 10 (February 2018 PTF) for 13.1
XL C for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C/C++ for AIX Fix Pack 20 (March 2018 Update) for 12.1
XL C for AIX Fix Pack 4 (July 2015 PTF) for 13.1
XL C for AIX Fix Pack 13 (August 2015 Update) for 12.1
XL C for AIX Fix Pack 14 (December 2015 Update) for 12.1
XL C/C++ for AIX Fix Pack 11 (November 2018 PTF) for 13.1
XL C for AIX Fix Pack 11 (November 2018) for 13.1
XL C/C++ for AIX Fix Pack 21 (January 2019 Update) for 12.1
XL C for AIX Fix Pack 21 (January 2019 Update) for 12.1

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APAR status

  • Closed as program error.

Error description

  • The offset value of a struct member calculated using the
    offsetof() function is incorrect when referencing designated
    initializer array elements using an enum.
    
    The issue is very sensitive to code changes.  Reordering the
    initializer list, or adding/removing struct members hides the
    issue.
    
    Manually calculating the offset, or using the offsetof()
    function in a context outside the initializer list works.
    
    
       ===  EXAMPLE  ===
    
    Note:  code is not compilable
    
    
    typedef struct
    {
      char          type1[32];
      unsigned int  type2;
      int           type3;
    } base_struct;
    
    enum
    {
      T_TYPE1,
      T_TYPE2,
      T_TYPE3
    };
    
    static const struct
    {
      int   offset;
      int   num;
      char  name[12];
    } my_struct_with_init_list[T_TYPE3 + 1] =
    {
      [T_TYPE1] = {offsetof(base_struct, type1) , 0, "type1"},
      [T_TYPE2] = {offsetof(base_struct, type2) , 0, "type2"},
      [T_TYPE3] = {offsetof(base_struct, type3) , 0, "type3"}
    };
    

Local fix

  • Do not calculate offsetof() in initializer list.
    

Problem summary

  • PROBLEM DESCRIPTION:
    The compiler is having problems calculating the offset value of
    a struct member via the offsetof() function inside a designated
    initializer list when string members exist.
    
    USERS AFFECTED:
    Users of the offsetof() function in designated initializers
    having string members.
    

Problem conclusion

  • A fix has been implemented.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV70769

  • Reported component name

    XL C/C++ FOR AI

  • Reported component ID

    5725C7200

  • Reported release

    C10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-03-10

  • Closed date

    2015-05-25

  • Last modified date

    2015-05-25

  • 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 FOR AIX

  • Fixed component ID

    5725C7100

Applicable component levels

  • RC10 PSY

       UP



Document information

More support for: XL C for AIX
Compiler

Software version: 12.1

Reference #: IV70769

Modified date: 25 May 2015