gfortran-14.1.1: issue with -Jpath search order

[Satish Balay <balay.anl@fastmail.org>]

A test case:

>>>>>>>>>
$ ls
incdir/  moddir/  srcdir/
$ ls incdir/
$ ls moddir/
$ ls srcdir/
modtest.F90
$ cat srcdir/modtest.F90 
module modtest
integer a
end module
program main
use modtest
end
$ gfortran --version
GNU Fortran (GCC) 14.1.1 20240522 (Red Hat 14.1.1-4)
Copyright (C) 2024 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ strace --follow-forks -o trace.log gfortran -Jmoddir -Iincdir srcdir/modtest.F90
$ 
<<<<

From trace.log:

>>>>
231249 openat(AT_FDCWD, "moddir/modtest.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
231249 unlink("moddir/modtest.mod")     = -1 ENOENT (No such file or directory)
231249 rename("moddir/modtest.mod0", "moddir/modtest.mod") = 0
231249 openat(AT_FDCWD, "modtest.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
231249 openat(AT_FDCWD, "srcdir/modtest.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
231249 openat(AT_FDCWD, "incdir/modtest.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
231249 openat(AT_FDCWD, "moddir/modtest.mod", O_RDONLY) = 5
<<<<

i.e after moddir/modtest.mod is created - its searched for in the following order:

- pwd
- src-file-dir
- -Ipath
- -Jpath

With this search order - a buggy/old/incorrect modtest.mod in pwd or src-file-dir gets picked up - resulting in broken builds.

Checking ifx from OneAPI - i see:

>>>>
$ ifx --version
ifx (IFORT) 2023.0.0 20221201
Copyright (C) 1985-2022 Intel Corporation. All rights reserved.

$ ifx --help |& grep -A2 \\-module
-module path
           specify path where mod files should be placed and first location to
           look for mod files
<<<<
Here with ifx - I don't get into the issue with picking up buggy/old/incorrect modtest.mod. With a slightly tweaked test:

>>>>>>>>
$ cat srcdir/modtest.F90
module modtest
integer a
end module
program main
use modtestwrong
end
$ strace --follow-forks -o trace.log ifx -module moddir -Iincdir srcdir/modtest.F90
srcdir/modtest.F90(5): error #7002: Error in opening the compiled module file.  Check INCLUDE paths.   [MODTESTWRONG]
use modtestwrong
----^
compilation aborted for srcdir/modtest.F90 (code 1)
$ 
<<<

trace.log has:

>>>
1573952 openat(AT_FDCWD, "moddir/modtestwrong.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
1573952 openat(AT_FDCWD, "modtestwrong.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
1573952 openat(AT_FDCWD, "srcdir/modtestwrong.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
1573952 openat(AT_FDCWD, "./modtestwrong.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
1573952 openat(AT_FDCWD, "incdir/modtestwrong.mod", O_RDONLY) = -1 ENOENT (No such file or directory)
...
<<<<
[i.e; -Jpath is searched first, then pwd, src-file-dir, ./, -Ipath, ...]

So is this a bug in gfortran?

thanks,
Satish