[Bug driver/89026] New: [mingw] -I directives in response files assume C:/ as '/', but C:/msys2 when passed directly

[felipe at expertisesolutions dot com.br]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89026

            Bug ID: 89026
           Summary: [mingw] -I directives in response files assume C:/ as
                    '/', but C:/msys2 when passed directly
           Product: gcc
           Version: 7.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: driver
          Assignee: unassigned at gcc dot gnu.org
          Reporter: felipe at expertisesolutions dot com.br
  Target Milestone: ---

If you create a response file with the following content:

<file abc.rsp>
-I/mingw64/include/dbus-1.0 -c -o abc.o abc
</file>

and call the compiler to the following C file:
<file abc.c>
#include <dbus/dbus.h>
</file>

With the following parameters:

gcc @abc.rsp

it will return that it did not find dbus/dbus.h. However, if you call with the
following parameters:

gcc -I/mingw64/include/dbus-1.0 -c -o abc.o abc

Then the compilation errors on another header that dbus.h tries to include.

Also, the response file works (complaining about other header inside dbus.h)
when we change it like this:

<file abc.rsp>
-I/msys64/mingw64/include/dbus-1.0 -c -o abc.o abc
</file>


Regards,