c/1536: -L and -I with bad paths do not raise a warning

[eyal at eyal dot emu dot id dot au]

>Number:         1536
>Category:       c
>Synopsis:       -L and -I with bad paths do not raise a warning
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Tue Jan 02 14:26:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     eyal@eyal.emu.id.au
>Release:        2.95.2
>Organization:
>Environment:
Linux 2.4, Debian 2.2
>Description:
When a invalid path is specified for the -I or -L options
there is no warning or error. This can cause a quiet usage
of the wrongs header/library.

While at times this is a desirable feature, I find myself
wanting these warnings when building complex projects
where some files may have the same name in different
directories.
>How-To-Repeat:
gcc -Wall -o test -L/xxx -I/xxx test.c
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: application/octet-stream; name="test.c"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.c"