Dear all,
the passing of procedure arguments in Fortran sometimes requires
ancillary parameters that are "hidden". Examples are string length
and the presence status of scalar variables with optional+value
attribute.
The gfortran ABI is actually documented:
https://gcc.gnu.org/onlinedocs/gfortran/Argument-passing-conventions.html
The reporter found that there was a discrepancy between the
caller and the callee. This is corrected by the attached patch.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
Thanks,
Harald
From b7646403557eca19612c81437f381d4b4dcd51c8 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anl...@gmx.de>
Date: Fri, 28 Oct 2022 21:58:08 +0200
Subject: [PATCH] Fortran: ordering of hidden procedure arguments [PR107441]
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.
gcc/testsuite/ChangeLog:
PR fortran/107441
* gfortran.dg/optional_absent_6.f90: New test.
---
gcc/fortran/trans-decl.cc | 15 +++--
.../gfortran.dg/optional_absent_6.f90 | 60 +++++++++++++++++++
2 files changed, 71 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/optional_absent_6.f90
diff --git a/gcc/fortran/trans-decl.cc b/gcc/fortran/trans-decl.cc
index 63515b9072a..18842fe2c4b 100644
--- a/gcc/fortran/trans-decl.cc
+++ b/gcc/fortran/trans-decl.cc
@@ -2508,7 +2508,7 @@ create_function_arglist (gfc_symbol * sym)
tree fndecl;
gfc_formal_arglist *f;
tree typelist, hidden_typelist;
- tree arglist, hidden_arglist;
+ tree arglist, hidden_arglist, optional_arglist, strlen_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;
+ strlen_arglist = optional_arglist = NULL_TREE;
typelist = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
if (sym->attr.entry_master)
@@ -2644,7 +2645,7 @@ create_function_arglist (gfc_symbol * sym)
length = build_decl (input_location,
PARM_DECL, get_identifier (name), len_type);
- hidden_arglist = chainon (hidden_arglist, length);
+ strlen_arglist = chainon (strlen_arglist, length);
DECL_CONTEXT (length) = fndecl;
DECL_ARTIFICIAL (length) = 1;
DECL_ARG_TYPE (length) = len_type;
@@ -2712,7 +2713,7 @@ create_function_arglist (gfc_symbol * sym)
PARM_DECL, get_identifier (name),
boolean_type_node);
- hidden_arglist = chainon (hidden_arglist, tmp);
+ optional_arglist = chainon (optional_arglist, tmp);
DECL_CONTEXT (tmp) = fndecl;
DECL_ARTIFICIAL (tmp) = 1;
DECL_ARG_TYPE (tmp) = boolean_type_node;
@@ -2863,10 +2864,16 @@ create_function_arglist (gfc_symbol * sym)
typelist = TREE_CHAIN (typelist);
}
+ /* Add hidden present status for optional+value arguments. */
+ arglist = chainon (arglist, optional_arglist);
+
/* Add the hidden string length parameters, unless the procedure
is bind(C). */
if (!sym->attr.is_bind_c)
- arglist = chainon (arglist, hidden_arglist);
+ arglist = chainon (arglist, strlen_arglist);
+
+ /* Add hidden extra arguments for the gfortran library. */
+ arglist = chainon (arglist, hidden_arglist);
gcc_assert (hidden_typelist == NULL_TREE
|| TREE_VALUE (hidden_typelist) == void_type_node);
diff --git a/gcc/testsuite/gfortran.dg/optional_absent_6.f90 b/gcc/testsuite/gfortran.dg/optional_absent_6.f90
new file mode 100644
index 00000000000..b8abb06980a
--- /dev/null
+++ b/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
--
2.35.3
