https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113975
Bug ID: 113975
Summary: function returning array is not fully evaluated before
assignement
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: comptes at ugo235 dot fr
Target Milestone: ---
The following code is poorly designed, yet I think it is standard-conforming:
======================================
module foo
implicit none
integer, parameter :: n=3
integer :: a(n,n)
contains
pure function bar()
integer :: bar(n,n)
bar = transpose(a)
end function bar
end module foo
program main
use foo
implicit none
integer :: i
a = reshape([ 11, 12, 13 &
, 21, 22, 23 &
, 31, 32, 33 ], shape=[n,n], order=[2,1] )
a = bar()
do i = 1, n
print*, a(i,:)
end do
end program main
======================================
In `a = bar()`, `bar()` should be fully evaluated before the result is assigned
to `a`, and it seems this is not the case. Consequently, the output of the
program compiled with gfortran 13.2 (without any option) is not the transpose
of the matrix that is entered in the code:
======================================
Program returned: 0
Program stdout
11 12 13
12 22 23
13 23 33
======================================
