[Bug rtl-optimization/89490] [9 Regression] char array constant put in string merge section

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89490

--- Comment #14 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
(In reply to Jakub Jelinek from comment #13)
> 
> Well, it matches what output_constant does:
>         case STRING_CST:
>           thissize = (unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp);
>           if (merge_strings
>               && (thissize == 0
>                   || TREE_STRING_POINTER (exp) [thissize - 1] != '\0'))
>             thissize++;
> (using MAX just in case there is already some extra padding in the length or
> whatever else).

Ah, well. Just FYI, this check in output_constant

  if (size == 0 || flag_syntax_only)
    return size;

prevents zero-padding of strings with STRING_LENGTH==0 && DECL_SIZE==0.

But due to the check in mergeable_string_section

      && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
      && TREE_STRING_LENGTH (decl) == len)

we should not get size==0 or thissize == 0 in a merge_strings section.
So it should not make a difference what happens with thissize==0.