topic Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT in Application Development and Automation Discussions

casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Sandra_Rossi — Mon, 10 Aug 2009 08:52:45 GMT

Hello all,

in my utf-16 little endian system (unicode system, 4103 system code page), I have this little program which dumps at the ASSIGN statement (exception ASSIGN_BASE_WRONG_ALIGNMENT). For information, I made sure that the program has the unicode check property active (in case there would be some bug around that).

Maybe it's a kernel problem, I use Linux x86_64.

Could you check this code, and if it works for you, could you please tell your kernel + your system code page (via SNLS transaction).


DATA x1 type x length 4.
field-symbols <c> type c.
x1 = '41004100'. "AA in utf-16 little endian
assign x1(4) to <c> casting. "<--- DUMP
write <c>.

The dump says:


In the current program, an error occurred when setting the field symbol "<C>" with ASSIGN or ASSIGNING (maybe in the combination with  the CASTING addition).
When converting the base entry of the field symbol "<C>" (number in base table: 13), it was found that the target type requests a memory alignment of 2.
However, the source data object has an invalid memory alignment, that is an alignment not divisible by 2.
You may be able to avoid the error by using a different offset. The following must apply: Offset = n * 2, n >= 0

I forgot to say that I checked SAP notes and none corresponds to that issue; they only explain the general problems of alignment which is not the case here (I guess) <-- Added by: Sandra Rossi on Aug 10, 2009 11:08 AM

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Former Member — Mon, 10 Aug 2009 09:20:34 GMT

I Ran this code snippet and did not get any Dump. O/P was A#A#(Looks like not appropriate Code page as well)

Database codepage                   1100     
Current Codepage of Appl. Server    1100     
Codepage of Front End               1160     
Kernal :700_REL

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Former Member — Mon, 10 Aug 2009 09:20:45 GMT

I've got the same dump, codepage 4102

Max

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Sandra_Rossi — Mon, 10 Aug 2009 09:36:36 GMT

thank you Amit and Max.

What operating systems do you use (windows 32/64, linux, unix...), and do you think it could be a bug in the sap kernel, or is there an easy workaround? (I made a "little" routine as a workaround which is not so simple!)

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Former Member — Mon, 10 Aug 2009 10:03:56 GMT

Have you checked the notes 303607 and 538119 and 766876?

Max

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Sandra_Rossi — Mon, 10 Aug 2009 10:43:39 GMT

Yes. These notes just point out casting and alignment issues in "old" releases (*), and I feel I understand everything that is mentioned. But in the case of X to C, there shouldn't be any alignment issue (I made sure to have an X length which is a multiple of 4 bytes, the widest character size possible).

(*) I forgot to say my SAP system is 7.0 SP 13, and sap kernel is 700 Linux GNU SLES-9 patch 179.

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Sandra_Rossi — Tue, 18 Aug 2009 10:00:06 GMT

Here I just share my "little" generic routine to cast from X (or xstring) to C (string, N... or any other character-type data). I would be happy if someone could share a simplest way to do the same (I close this thread but don't hesitate to answer this last question ). After this routine, there is a demo.


*----------------------------------------------------------------------*
FORM cast_copy_xstring_to_string
      USING
        i_xsequence           TYPE xsequence
        i_ignore_size_error   TYPE flag
      CHANGING
        e_string              TYPE clike
        e_xstring_size_error  TYPE flag.
  CONSTANTS con_xbuffer_size TYPE i VALUE 10000. "large buffer, max 65535, multiple of charsize
  DATA l_xbuffer TYPE x LENGTH con_xbuffer_size.
  FIELD-SYMBOLS <l_c> TYPE c.
  DATA l_xsequence_len TYPE i.
  DATA l_xsequence_type TYPE c.
  DATA l_pos TYPE i.
  DATA l_len TYPE i.
  DATA l_temp TYPE i.

  CLEAR e_string.
  CLEAR e_xstring_size_error.

* make sure the buffer size is a multiple of charsize
  l_temp = con_xbuffer_size MOD cl_abap_char_utilities=>charsize.
  ASSERT l_temp = 0 AND con_xbuffer_size >= cl_abap_char_utilities=>charsize.

  l_pos = 0.
  DESCRIBE FIELD i_xsequence TYPE l_xsequence_type LENGTH l_xsequence_len IN BYTE MODE.
  IF l_xsequence_type = cl_abap_typedescr=>TYPEKIND_XSTRING.
    l_xsequence_len = XSTRLEN( I_xsequence ). "before 6.10, use STRLEN
  ENDIF.

  l_temp = l_xsequence_len MOD cl_abap_char_utilities=>charsize.
  IF l_temp <> 0 AND i_ignore_size_error IS INITIAL.
    e_xstring_size_error = 'X'.
  ELSE.
    l_len = con_xbuffer_size.
    DO.
      IF l_pos >= l_xsequence_len.
        EXIT.
      ENDIF.
      l_temp = l_pos + con_xbuffer_size.
      IF l_temp >= l_xsequence_len.
* last bytes
        l_len = l_xsequence_len - l_pos.
        l_xbuffer = i_xsequence+l_pos(l_len).
* Adjust length on the last bytes in case the input x size does not fit character size
        IF i_ignore_size_error IS NOT INITIAL.
          l_len = ( l_len / cl_abap_char_utilities=>charsize ) * cl_abap_char_utilities=>charsize.
        ENDIF.
      ELSE.
        l_xbuffer = i_xsequence+l_pos(l_len).
      ENDIF.
      ASSIGN l_xbuffer(l_len) TO <l_c> CASTING.
      CONCATENATE e_string <l_c> INTO e_string.
      ADD con_xbuffer_size TO l_pos.
    ENDDO.
  ENDIF.
ENDFORM.

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Sandra_Rossi — Tue, 18 Aug 2009 10:00:50 GMT

I forgot the demo part:


DATA l_string TYPE string.
DATA l_error TYPE flag.

IF cl_i18n_search_utils=>system_codepage( ) = '1100'.       "iso-8859-1
  PERFORM cast_copy_xstring_to_string USING '41424344' '' CHANGING l_string l_error.
  ASSERT l_error IS INITIAL AND l_string = 'ABCD'.
ELSEIF cl_i18n_search_utils=>system_codepage( ) = '4103'.   "utf16-le
  PERFORM cast_copy_xstring_to_string USING '4100420043004400' '' CHANGING l_string l_error.
  ASSERT l_error IS INITIAL AND l_string = 'ABCD'.
  PERFORM cast_copy_xstring_to_string USING '41004200430044' '' CHANGING l_string l_error.
  ASSERT l_error = 'X'.
  PERFORM cast_copy_xstring_to_string USING '41004200430044' 'X' CHANGING l_string l_error.
  ASSERT l_error IS INITIAL AND l_string = 'ABCD'.
ENDIF.

Re: casting X to C : ASSIGN_BASE_WRONG_ALIGNMENT

Sandra_Rossi — Mon, 05 Oct 2009 09:37:57 GMT

More simple version of the routine above. It assumes the input X or XSTRING is a valid string of characters in the system encoding (codepage), so that to simplify the code (I removed the 2 error parameters). It is based on the fact that the conversion classes do not convert bytes if the input and output encodings (i.e. codepages) are the same.


FORM cast_copy_xstring_to_string
      USING
        i_xsequence           TYPE xsequence
      CHANGING
        e_string              TYPE clike.
  DATA enc TYPE abap_encod.
  DATA conv TYPE REF TO cl_abap_conv_in_ce.
  enc = cl_i18n_search_utils=>system_codepage( ).
  conv = cl_abap_conv_in_ce=>create( ENCODING = enc ).
  conv->convert(
    EXPORTING INPUT = i_xsequence
    IMPORTING DATA = e_string ).
ENDFORM.