[patch, Fortran] Fix -mod(unsigned, unsigned)

[Thomas Koenig]

Hello world,

during testing, I noticed that parameters of the form
- mod(u1,u2) were rejected with an unknown type. The fix
is straightforward, but required an adjustment to another
test case.

Regression-tested.  OK for trunk?

gcc/fortran/ChangeLog:

        * resolve.cc (resolve_operator): Also handle BT_UNSIGNED.

gcc/testsuite/ChangeLog:

        * gfortran.dg/unsigned_38.f90: Add -pedantic and adjust error
        message.
        * gfortran.dg/unsigned_40.f90: New test.
diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 565d4aa5fe9..535fa08b13b 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -4253,7 +4253,8 @@ resolve_operator (gfc_expr *e)
     case INTRINSIC_UMINUS:
       if (op1->ts.type == BT_INTEGER
 	  || op1->ts.type == BT_REAL
-	  || op1->ts.type == BT_COMPLEX)
+	  || op1->ts.type == BT_COMPLEX
+	  || op1->ts.type == BT_UNSIGNED)
 	{
 	  e->ts = op1->ts;
 	  break;
diff --git a/gcc/testsuite/gfortran.dg/unsigned_38.f90 b/gcc/testsuite/gfortran.dg/unsigned_38.f90
index d549483b269..ac1cfb33aac 100644
--- a/gcc/testsuite/gfortran.dg/unsigned_38.f90
+++ b/gcc/testsuite/gfortran.dg/unsigned_38.f90
@@ -1,6 +1,6 @@
 ! { dg-do compile }
-! { dg-options "-funsigned" }
+! { dg-options "-funsigned -pedantic" }
 program main
   unsigned, parameter :: u = 7u
-  print *,mod(-(u+1u),u) ! { dg-error "Operand of unary numeric operator" }
+  print *,mod(-(u+1u),u) ! { dg-error "Negation of unsigned expression" }
 end program main
diff --git a/gcc/testsuite/gfortran.dg/unsigned_40.f90 b/gcc/testsuite/gfortran.dg/unsigned_40.f90
new file mode 100644
index 00000000000..129fc883f17
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/unsigned_40.f90
@@ -0,0 +1,19 @@
+! { dg-do run }
+! { dg-options "-funsigned" }
+program memain
+  use iso_fortran_env, only : uint8
+  call test1
+  call test2
+contains
+  subroutine test1
+    unsigned(uint8) :: nface, nmax
+    nface = 12u_1
+    nmax = - mod(-nface+1u,nface)
+    if (nmax /= 251u_1) error stop 1
+  end subroutine test1
+  subroutine test2
+    unsigned(uint8), parameter :: nface = 12u_1
+    unsigned(uint8), parameter :: nmax = - mod(-nface+1u,nface)
+    if (nmax /= 251u_1) error stop 11
+  end subroutine test2
+end program memain