Fortran: ordering of hidden procedure arguments [PR107441]

The gfortran ABI specifies the order of given and hidden procedure arguments,
where the hidden presence status flags of optional+value scalar arguments
shall come before character length, coarray token and offset.  Respect that.

gcc/fortran/ChangeLog:

	PR fortran/107441
	* trans-decl.cc (create_function_arglist): Adjust the ordering of
	automatically generated hidden procedure arguments to match the
	documented ABI for gfortran.
	* trans-types.cc (gfc_get_function_type): Separate hidden parameters
	so that the presence flag for optional+value arguments come before
	string length, coarray token and offset, as required.

gcc/testsuite/ChangeLog:

	PR fortran/107441
	* gfortran.dg/coarray/pr107441-caf.f90: New test.
	* gfortran.dg/optional_absent_6.f90: New test.
	* gfortran.dg/optional_absent_7.f90: New test.

gcc/fortran/trans-decl.cc

@@ -2507,8 +2507,8 @@ create_function_arglist (gfc_symbol * sym)
 {
   tree fndecl;
   gfc_formal_arglist *f;
-  tree typelist, hidden_typelist;
+  tree typelist, hidden_typelist, optval_typelist;
-  tree arglist, hidden_arglist;
+  tree arglist, hidden_arglist, optval_arglist;
   tree type;
   tree parm;
 
@@ -2518,6 +2518,7 @@ create_function_arglist (gfc_symbol * sym)
      the new FUNCTION_DECL node.  */
   arglist = NULL_TREE;
   hidden_arglist = NULL_TREE;
+  optval_arglist = NULL_TREE;
   typelist = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
 
   if (sym->attr.entry_master)
@@ -2619,6 +2620,15 @@ create_function_arglist (gfc_symbol * sym)
     if (f->sym != NULL)	/* Ignore alternate returns.  */
       hidden_typelist = TREE_CHAIN (hidden_typelist);
 
+  /* Advance hidden_typelist over optional+value argument presence flags.  */
+  optval_typelist = hidden_typelist;
+  for (f = gfc_sym_get_dummy_args (sym); f; f = f->next)
+    if (f->sym != NULL
+	&& f->sym->attr.optional && f->sym->attr.value
+	&& !f->sym->attr.dimension && f->sym->ts.type != BT_CLASS
+	&& !gfc_bt_struct (f->sym->ts.type))
+      hidden_typelist = TREE_CHAIN (hidden_typelist);
+
   for (f = gfc_sym_get_dummy_args (sym); f; f = f->next)
     {
       char name[GFC_MAX_SYMBOL_LEN + 2];
@@ -2712,14 +2722,16 @@ create_function_arglist (gfc_symbol * sym)
 			    PARM_DECL, get_identifier (name),
 			    boolean_type_node);
 
-          hidden_arglist = chainon (hidden_arglist, tmp);
+	  optval_arglist = chainon (optval_arglist, tmp);
           DECL_CONTEXT (tmp) = fndecl;
           DECL_ARTIFICIAL (tmp) = 1;
           DECL_ARG_TYPE (tmp) = boolean_type_node;
           TREE_READONLY (tmp) = 1;
           gfc_finish_decl (tmp);
 
-	  hidden_typelist = TREE_CHAIN (hidden_typelist);
+	  /* The presence flag must be boolean.  */
+	  gcc_assert (TREE_VALUE (optval_typelist) == boolean_type_node);
+	  optval_typelist = TREE_CHAIN (optval_typelist);
 	}
 
       /* For non-constant length array arguments, make sure they use
@@ -2863,6 +2875,9 @@ create_function_arglist (gfc_symbol * sym)
       typelist = TREE_CHAIN (typelist);
     }
 
+  /* Add hidden present status for optional+value arguments.  */
+  arglist = chainon (arglist, optval_arglist);
+
   /* Add the hidden string length parameters, unless the procedure
      is bind(C).  */
   if (!sym->attr.is_bind_c)

gcc/fortran/trans-types.cc

@@ -3105,6 +3105,7 @@ gfc_get_function_type (gfc_symbol * sym, gfc_actual_arglist *actual_args,
 {
   tree type;
   vec<tree, va_gc> *typelist = NULL;
+  vec<tree, va_gc> *hidden_typelist = NULL;
   gfc_formal_arglist *f;
   gfc_symbol *arg;
   int alternate_return = 0;
@@ -3222,7 +3223,7 @@ gfc_get_function_type (gfc_symbol * sym, gfc_actual_arglist *actual_args,
 	       so that the value can be returned.  */
 	    type = build_pointer_type (gfc_charlen_type_node);
 
-	  vec_safe_push (typelist, type);
+	  vec_safe_push (hidden_typelist, type);
 	}
       /* For noncharacter scalar intrinsic types, VALUE passes the value,
 	 hence, the optional status cannot be transferred via a NULL pointer.
@@ -3245,11 +3246,15 @@ gfc_get_function_type (gfc_symbol * sym, gfc_actual_arglist *actual_args,
 		  && CLASS_DATA (arg)->attr.codimension
 		  && !CLASS_DATA (arg)->attr.allocatable)))
 	{
-	  vec_safe_push (typelist, pvoid_type_node);  /* caf_token.  */
+	  vec_safe_push (hidden_typelist, pvoid_type_node);  /* caf_token.  */
-	  vec_safe_push (typelist, gfc_array_index_type);  /* caf_offset.  */
+	  vec_safe_push (hidden_typelist, gfc_array_index_type);  /* caf_offset.  */
 	}
     }
 
+  /* Put hidden character length, caf_token, caf_offset at the end.  */
+  vec_safe_reserve (typelist, vec_safe_length (hidden_typelist));
+  vec_safe_splice (typelist, hidden_typelist);
+
   if (!vec_safe_is_empty (typelist)
       || sym->attr.is_main_program
       || sym->attr.if_source != IFSRC_UNKNOWN)

gcc/testsuite/gfortran.dg/coarray/pr107441-caf.f90

@@ -0,0 +1,27 @@
+! { dg-do run }
+!
+! PR fortran/107441
+! Check that with -fcoarray=lib, coarray metadata arguments are passed
+! in the right order to procedures.
+!
+! Contributed by M.Morin
+
+program p
+  integer :: ci[*]
+  ci = 17
+  call s(1, ci, "abcd")
+contains
+  subroutine s(ra, ca, c)
+    integer :: ra, ca[*]
+    character(*) :: c
+    ca[1] = 13
+    if (ra /= 1) stop 1
+    if (this_image() == 1) then
+      if (ca /= 13) stop 2
+    else
+      if (ca /= 17) stop 3
+    end if
+    if (len(c) /= 4) stop 4
+    if (c /= "abcd") stop 5
+  end subroutine s
+end program p

gcc/testsuite/gfortran.dg/optional_absent_6.f90

@@ -0,0 +1,60 @@
+! { dg-do run }
+! PR fortran/107441
+!
+! Test VALUE + OPTIONAL for integer/real/...
+! in the presence of non-optional character dummies
+
+program bugdemo
+  implicit none
+  character :: s = 'a'
+  integer   :: t
+
+  t = testoptional(s)
+  call test2 (s)
+  call test3 (s)
+  call test4 (w='123',x=42)
+
+contains
+
+  function testoptional (w, x) result(t)
+    character, intent(in)                  :: w
+    integer,   intent(in), value, optional :: x
+    integer :: t
+    print *, 'present(x) is', present(x)
+    t = 0
+    if (present (x)) stop 1
+  end function testoptional
+
+  subroutine test2 (w, x)
+    character, intent(in)                  :: w
+    integer,   intent(in), value, optional :: x
+    print*, 'present(x) is', present(x)
+    if (present (x)) stop 2
+  end subroutine test2
+
+  subroutine test3 (w, x)
+    character, intent(in),        optional :: w
+    integer,   intent(in), value, optional :: x
+    print *, 'present(w) is', present(w)
+    print *, 'present(x) is', present(x)
+    if (.not. present (w)) stop 3
+    if (present (x)) stop 4
+  end subroutine test3
+
+  subroutine test4 (r, w, x)
+    real,                     value, optional :: r
+    character(*), intent(in),        optional :: w
+    integer,                  value, optional :: x
+    print *, 'present(r) is', present(r)
+    print *, 'present(w) is', present(w)
+    print *, 'present(x) is', present(x)
+    if (present (r)) stop 5
+    if (.not. present (w)) stop 6
+    if (.not. present (x)) stop 7
+    print *, 'x=', x
+    print *, 'len(w)=', len(w)
+    if (len(w) /= 3) stop 8
+    if (x /= 42) stop 9
+  end subroutine test4
+
+end program bugdemo

gcc/testsuite/gfortran.dg/optional_absent_7.f90

@@ -0,0 +1,31 @@
+! { dg-do run }
+! { dg-additional-options "-fdump-tree-original" }
+!
+! PR fortran/107441
+! Check that procedure types and procedure decls match when the procedure
+! has both character-typed and optional value args.
+!
+! Contributed by M.Morin
+
+program p
+  interface
+    subroutine i(c, o)
+      character(*) :: c
+      integer, optional, value :: o
+    end subroutine i
+  end interface
+  procedure(i), pointer :: pp
+  pp => s
+  call pp("abcd")
+contains
+  subroutine s(c, o)
+    character(*) :: c
+    integer, optional, value :: o
+    if (present(o)) stop 1
+    if (len(c) /= 4) stop 2
+    if (c /= "abcd") stop 3
+  end subroutine s
+end program p
+
+! { dg-final { scan-tree-dump "void s .* c, .* o, logical.* _o, integer.* _c" "original" } }
+! { dg-final { scan-tree-dump ", integer.*, logical.*, integer.* pp" "original" } }