https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109358
Bug ID: 109358
Summary: Wrong formatting with T-descriptor during stream
output
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: baradi09 at gmail dot com
Target Milestone: ---
This is a very minor bug, but probably easy to fix. It seems, that the T data
edit descriptor handling is non-standard conforming when using formatted stream
I/O:
Given the following MWE:
program tabformat
implicit none
integer :: fd
open(newunit=fd, file="test.stream.txt", access="stream", form="formatted")
write(fd, "(a)") "1234567890123"
write(fd, "(a, t10, a)") "1234", "0123" ! A-descriptor, file positioning
allowed
write(fd, "(i4, t10, i4.4)") 1234, 0123 ! I-descriptor, file positioning
not allowed
close(fd)
end program tabformat
The resulting file contains
1234567890123
1234 0123 # 9 spaces between blocks
1234 0123 # 9 spaces between blocks
Apparently, a file positioning takes place during the execution of the write
statement.
However, if I understand 13.7.1 ยง1 correctly, file positioning may only happen
with the A-descriptor (and it is optional even there). So the standard
conforming output would be either (if file positioning happens after the
A-descriptor)
1234567890123
1234 0123 # 9 spaces
1234 0123 # 5 spaces
or (if no file positioning happens after the A-descriptor)
1234567890123
1234 0123 # 5 spaces
1234 0123 # 5 spaces
I personally would prefer latter, and it would be also equivalent to the
behavior of the Intel and NAG compilers.
