Fortran: diagnostics for actual arguments to pointer dummy arguments [PR94104]

Error message improvement.  In Fortran 2008 actual procedure arguments
associated with a pointer, intent(in) attribute, dummy argument
can also have the target attribute, not just pointer.

gcc/fortran/ChangeLog:

	PR fortran/94104
	* interface.cc (gfc_compare_actual_formal): Improve error message
	dependent on Fortran standard level.

gcc/testsuite/ChangeLog:

	PR fortran/94104
	* gfortran.dg/parens_2.f90: Adjust to improved error message.
	* gfortran.dg/PR94104a.f90: New test.
	* gfortran.dg/PR94104b.f90: New test.

4 files changed, 90 insertions, 18 deletions

diff --git a/gcc/fortran/interface.cc b/gcc/fortran/interface.cc
index d3e1995..49dbd1d 100644
--- a/gcc/fortran/interface.cc
+++ b/gcc/fortran/interface.cc
@@ -3477,25 +3477,39 @@ gfc_compare_actual_formal (gfc_actual_arglist **ap, gfc_formal_arglist *formal,
 	  goto match;
 	}
 
-      if (a->expr->expr_type != EXPR_NULL
-	  && compare_pointer (f->sym, a->expr) == 0)
+      if (a->expr->expr_type != EXPR_NULL)
 	{
-	  if (where)
-	    gfc_error ("Actual argument for %qs must be a pointer at %L",
-		       f->sym->name, &a->expr->where);
-	  ok = false;
-	  goto match;
-	}
+	  int cmp = compare_pointer (f->sym, a->expr);
+	  bool pre2008 = ((gfc_option.allow_std & GFC_STD_F2008) == 0);
 
-      if (a->expr->expr_type != EXPR_NULL
-	  && (gfc_option.allow_std & GFC_STD_F2008) == 0
-	  && compare_pointer (f->sym, a->expr) == 2)
-	{
-	  if (where)
-	    gfc_error ("Fortran 2008: Non-pointer actual argument at %L to "
-		       "pointer dummy %qs", &a->expr->where,f->sym->name);
-	  ok = false;
-	  goto match;
+	  if (pre2008 && cmp == 0)
+	    {
+	      if (where)
+		gfc_error ("Actual argument for %qs at %L must be a pointer",
+			   f->sym->name, &a->expr->where);
+	      ok = false;
+	      goto match;
+	    }
+
+	  if (pre2008 && cmp == 2)
+	    {
+	      if (where)
+		gfc_error ("Fortran 2008: Non-pointer actual argument at %L to "
+			   "pointer dummy %qs", &a->expr->where, f->sym->name);
+	      ok = false;
+	      goto match;
+	    }
+
+	  if (!pre2008 && cmp == 0)
+	    {
+	      if (where)
+		gfc_error ("Actual argument for %qs at %L must be a pointer "
+			   "or a valid target for the dummy pointer in a "
+			   "pointer assignment statement",
+			   f->sym->name, &a->expr->where);
+	      ok = false;
+	      goto match;
+	    }
 	}
 
 
diff --git a/gcc/testsuite/gfortran.dg/PR94104a.f90 b/gcc/testsuite/gfortran.dg/PR94104a.f90
new file mode 100644
index 0000000..a1e578a
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/PR94104a.f90
@@ -0,0 +1,29 @@
+! { dg-do compile }
+! { dg-options "-std=f2003" }
+!
+! PR fortran/94104
+!
+
+program diag_p
+  implicit none
+
+  integer, parameter :: n = 7
+
+  integer         :: a(n)
+  integer, target :: b(n)
+
+  a = 1
+  print *, sumf(a) ! { dg-error "Actual argument for 'a' at .1. must be a pointer" }
+  print *, sumf(b) ! { dg-error "Fortran 2008: Non-pointer actual argument at .1. to pointer dummy 'a'" }
+
+contains
+
+  function sumf(a) result(s)
+    integer, pointer, intent(in) :: a(:)
+
+    integer :: s
+
+    s = sum(a)
+  end function sumf
+
+end program diag_p
diff --git a/gcc/testsuite/gfortran.dg/PR94104b.f90 b/gcc/testsuite/gfortran.dg/PR94104b.f90
new file mode 100644
index 0000000..ee7d640
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/PR94104b.f90
@@ -0,0 +1,29 @@
+! { dg-do compile }
+! { dg-options "-std=f2008" }
+!
+! PR fortran/94104
+!
+
+program diag_p
+  implicit none
+
+  integer, parameter :: n = 7
+
+  integer         :: a(n)
+  integer, target :: b(n)
+
+  a = 1
+  print *, sumf(a) ! { dg-error "Actual argument for 'a' at .1. must be a pointer or a valid target" }
+  print *, sumf(b)
+
+contains
+
+  function sumf(a) result(s)
+    integer, pointer, intent(in) :: a(:)
+
+    integer :: s
+
+    s = sum(a)
+  end function sumf
+
+end program diag_p
diff --git a/gcc/testsuite/gfortran.dg/parens_2.f90 b/gcc/testsuite/gfortran.dg/parens_2.f90
index bc2acd8..dc5965d 100644
--- a/gcc/testsuite/gfortran.dg/parens_2.f90
+++ b/gcc/testsuite/gfortran.dg/parens_2.f90
@@ -2,7 +2,7 @@
 ! { dg-do compile }
 ! Originally contributed by Joost VandeVondele
 INTEGER, POINTER :: I
-CALL S1((I)) ! { dg-error "Actual argument for .i. must be a pointer" }
+CALL S1((I)) ! { dg-error "Actual argument for .i. at .1. must be a pointer or a valid target" }
 CONTAINS
  SUBROUTINE S1(I)
   INTEGER, POINTER ::I