https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98534
Bug ID: 98534
Summary: Intrinsic functions failing with unlimited polymorphic
actual arguments
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: fortran
Assignee: pault at gcc dot gnu.org
Reporter: pault at gcc dot gnu.org
Target Milestone: ---
Created attachment 49891
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49891&action=edit
Provisional patch
Unlimited polymorphic actual arguments to 'storage_size' and 'transfer' fail,
when the dynamic type is character. This comes about because the '_len' field
is not used. The attached is a partial, provisional patch. I have not checked
other intrinsics yet.
It should also be noted that 'same_type_as' still uses the '_hash' field of the
vptr, rather than its address. This is known to fail in some cases.
A testcase can be found below.
Paul
! No errors with
character(*), parameter :: string = "abcdefgh"
class(*), allocatable :: star
character(len=:), allocatable :: chr
integer :: sz, sum1, sum2
! Part 1: works correctly
star = 1.0
sz = storage_size (star)/8
allocate (character(len=sz) :: chr)
chr = transfer (star, chr)
sum1 = sum ([(ichar(chr(i:i)), i = 1, sz)])
chr = transfer(1.0, chr)
sum2 = sum ([(ichar(chr(i:i)), i = 1, sz)])
if (sz /= kind (1.0)) stop 1
if (sum1 /= sum2) stop 2
deallocate (star) ! The automatic reallocation causes invalid writes
! and memory leaks. Even with this deallocation
! The invalid writes still occur.
deallocate (chr)
! Part 2: gets everything from because '_len' field of 'star' not used
star = string
sz = storage_size (star)/8
if (sz /= len (string)) print *, "stop 3" ! storage_size fails
sz = len (string) ! Ignore previous error in storage_size
allocate (character(len=sz) :: chr)
chr = transfer (star, chr)
sum1 = sum ([(ichar(chr(i:i)), i = 1, sz)])
chr = transfer(string, chr)
sum2 = sum ([(ichar(chr(i:i)), i = 1, sz)])
if (sum1 /= sum2) print *, "stop 4" ! transfer fails
deallocate (star, chr)
end
