ICE on bad syntax for character literals

[Harald1]

The following code compiles in fixed form, but has issues when treated as free form:

      integer, parameter :: ck = kind ("a")  ! default character kind
      print *, ck
      print *, ck_"a"   ! valid
      print *, ck _"a"  ! invalid, ICE
      print *, ck_ "a"  ! invalid, not detected
      print *, 1_"a"    ! valid
      print *, 1 _"a"   ! invalid, ICE
      print *, 1_ "a"   ! invalid, not detected
      end

% ifort ifort_bad_char_literal.f90 -fixed

--> OK.

% ifort ifort_bad_char_literal.f90
ifort_bad_char_literal.f90(4): error #5192: Lead underscore not allowed
      print *, ck _"a"  ! invalid, ICE
-------------------^
ifort_bad_char_literal.f90(4): error #5082: Syntax error, found CHAR_NAM_KIND_PARAM '' when expecting one of: :: ) ( , : * <END-OF-STATEMENT> ; . % (/ + - [ ] /) . ** / // ...
      print *, ck _"a"  ! invalid, ICE
------------------^
ifort_bad_char_literal.f90(7): error #5192: Lead underscore not allowed
      print *, 1 _"a"   ! invalid, ICE
------------------^
ifort_bad_char_literal.f90(7): error #5082: Syntax error, found CHAR_NAM_KIND_PARAM '' when expecting one of: :: ) , : * <END-OF-STATEMENT> ; . (/ + - ] /) ' ** / // > PRIVATE ...
      print *, 1 _"a"   ! invalid, ICE
-----------------^
ifort_bad_char_literal.f90: catastrophic error: **Internal compiler error: segmentation violation signal raised** Please report this error along with the circumstances in which it occurred in a Software Problem Report.  Note: File and line given may not be explicit cause of this error.
compilation aborted for ifort_bad_char_literal.f90 (code 1)

So I think there is accepted-invalid code, and there is an ICE-on-invalid, as indicated.

Thanks,

Harald