Dear all,
See also the discussion in the thread starting at
http://gcc.gnu.org/ml/fortran/2012-12/msg00135.html
a) The Fortran standard only defines LOGICAL(kind=C_Bool) as being
interoperable with C - no other LOGICAL type. That matches GCC: With gcc
(the C compiler) only _Bool is a BOOLEAN_TYPE with TYPE_PRECISION == 1.
Hence, this patch rejects other logical kinds as dummy argument/result
variable in BIND(C) procedures if -std=f2003/f2008/f2008ts is specified
(using -pedantic, one gets a warning).
b) As GNU extension, other logical kinds are accepted in BIND(C)
procedures; however, as the main use of "LOGICAL(kind=4)" (for BIND(C)
procedures) is to handle logical expressions which use C's int, one has
to deal with all integer values and not only 0 and 1. Hence, a normal
integer type is used internally in that case. That has been done to
avoid surprises of users and hard to trace bugs.
Note: logical(c_bool) and all logicals which are not dummy or result
variables of a bind(C) procedure remain BOOLEAN_TYPEs with
TYPE_PRECISION == 1 bit. For those a .true. with internal value "-1"
will lead the surprising result .not.(-1) => (-2) => .true., i.e. .true.
== .not. .true. But that's simply an invaliduse of those logicals and
not a bug in the compiler. (-> won't fix).
Build and regtested on x86-64-gnu-linux.
OK for the trunk?
Tobias
2012-12-27 Tobias Burnus <bur...@net-b.de>
PR fortran/55758
* resolve.c (resolve_symbol): Reject non-C_Bool logicals
in BIND(C) procedures with -std=f*.
* trans-types.c (gfc_sym_type): Use a non-BOOLEAN_TYPE
integer for non-C_Bool logicals in BIND(C) procedures.
* trans-expr.c (gfc_conv_unary_op): Add fold convert for
INTRINSIC_NOT.
2012-12-27 Tobias Burnus <bur...@net-b.de>
PR fortran/55758
* gfortran.dg/bind_c_bool_1.f90: New.
* gfortran.dg/bind_c_bool_2.f90: New.
* gfortran.dg/bind_c_bool_2_c.c: New.
* gfortran.dg/do_5.f90: Add dg-warning.
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 873400a..5963acd 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -13640,6 +13636,32 @@ resolve_symbol (gfc_symbol *sym)
return;
}
+ if (sym->ts.type == BT_LOGICAL
+ && ((sym->attr.function && sym->attr.is_bind_c && sym->result == sym)
+ || ((sym->attr.dummy || sym->attr.result) && sym->ns->proc_name
+ && sym->ns->proc_name->attr.is_bind_c)))
+ {
+ int i;
+ for (i = 0; gfc_logical_kinds[i].kind; i++)
+ if (gfc_logical_kinds[i].kind == sym->ts.kind)
+ break;
+ if (!gfc_logical_kinds[i].c_bool && sym->attr.dummy
+ && gfc_notify_std (GFC_STD_GNU, "LOGICAL dummy argument '%s' at %L "
+ "with non-C_Bool kind in BIND(C) procedure '%s'",
+ sym->name, &sym->declared_at,
+ sym->ns->proc_name->name) == FAILURE)
+ return;
+ else if (!gfc_logical_kinds[i].c_bool
+ && gfc_notify_std (GFC_STD_GNU, "LOGICAL result variable '%s' at"
+ " %L with non-C_Bool kind in BIND(C) "
+ "procedure '%s'", sym->name,
+ &sym->declared_at,
+ sym->attr.function ? sym->name
+ : sym->ns->proc_name->name)
+ == FAILURE)
+ return;
+ }
+
switch (sym->attr.flavor)
{
case FL_VARIABLE:
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index 452f2bc..bbfb162 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -1850,7 +1850,8 @@ gfc_conv_unary_op (enum tree_code code, gfc_se * se, gfc_expr * expr)
We must convert it to a compare to 0 (e.g. EQ_EXPR (op1, 0)).
All other unary operators have an equivalent GIMPLE unary operator. */
if (code == TRUTH_NOT_EXPR)
- se->expr = fold_build2_loc (input_location, EQ_EXPR, type, operand.expr,
+ se->expr = fold_build2_loc (input_location, EQ_EXPR, type,
+ fold_convert (type, operand.expr),
build_int_cst (type, 0));
else
se->expr = fold_build1_loc (input_location, code, type, operand.expr);
diff --git a/gcc/fortran/trans-types.c b/gcc/fortran/trans-types.c
index 8394bf9..73ed5aa 100644
--- a/gcc/fortran/trans-types.c
+++ b/gcc/fortran/trans-types.c
@@ -2128,6 +2128,25 @@ gfc_sym_type (gfc_symbol * sym)
&& sym->ns->proc_name
&& sym->ns->proc_name->attr.is_bind_c)))
type = gfc_character1_type_node;
+ else if (sym->ts.type == BT_LOGICAL
+ && ((sym->attr.function && sym->attr.is_bind_c)
+ || ((sym->attr.dummy || sym->attr.result) && sym->ns->proc_name
+ && sym->ns->proc_name->attr.is_bind_c)))
+ {
+ /* For LOGICAL dummy arguments or result value of a C binding procedure,
+ which do not match _Bool (C_Bool kind), a normal integer variable
+ is used instead of a BOOLEAN_TYPE with a TYPE_PRECISION of 1. The
+ reason is that on the C side, a normal integer such as "int" is used,
+ implying that any integer value could be used - not only 0 and 1. */
+ int i;
+ for (i = 0; gfc_logical_kinds[i].kind; i++)
+ if (gfc_logical_kinds[i].kind == sym->ts.kind)
+ break;
+ if (!gfc_logical_kinds[i].c_bool)
+ type = gfc_get_int_type (sym->ts.kind);
+ else
+ type = gfc_typenode_for_spec (&sym->ts);
+ }
else
type = gfc_typenode_for_spec (&sym->ts);
diff --git a/gcc/testsuite/gfortran.dg/bind_c_bool_1.f90 b/gcc/testsuite/gfortran.dg/bind_c_bool_1.f90
new file mode 100644
index 0000000..467bdc1
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bind_c_bool_1.f90
@@ -0,0 +1,25 @@
+! { dg-do compile }
+! { dg-options "-std=f2003" }
+!
+! PR fortran/55758
+!
+
+function sub2() bind(C) ! { dg-error "GNU Extension: LOGICAL result variable 'sub2' at .1. with non-C_Bool kind in BIND.C. procedure 'sub2'" }
+ logical(kind=8) :: sub2
+ logical(kind=4) :: local ! OK
+end function sub2
+
+function sub4() bind(C) result(res) ! { dg-error "GNU Extension: LOGICAL result variable 'res' at .1. with non-C_Bool kind in BIND.C. procedure 'sub4'" }
+ logical(kind=2) :: res
+ logical(kind=4) :: local ! OK
+end function sub4
+
+
+subroutine sub(x) bind(C) ! { dg-error "GNU Extension: LOGICAL dummy argument 'x' at .1. with non-C_Bool kind in BIND.C. procedure 'sub'" }
+ logical(kind=4) :: x
+end subroutine sub
+
+subroutine sub3(y) bind(C)
+ use iso_c_binding, only : c_bool
+ logical(kind=c_bool) :: y ! OK
+end subroutine sub3
diff --git a/gcc/testsuite/gfortran.dg/bind_c_bool_2.f90 b/gcc/testsuite/gfortran.dg/bind_c_bool_2.f90
new file mode 100644
index 0000000..1feb28d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bind_c_bool_2.f90
@@ -0,0 +1,32 @@
+! { dg-do run }
+! { dg-options "" }
+! { dg-additional-sources bind_c_bool_2_c.c }
+!
+! PR fortran/55758
+!
+! Ensure that logical(c_int) in a BIND(C) function is properly handled,
+! i.e. ".not.-1" is not "-2" but 0 as a C programmer would expect.
+!
+
+program main
+ use iso_c_binding, only : c_int, c_bool
+ implicit none
+ logical(4) :: result
+
+ interface
+ function C_true() bind(C, name="C_true")
+ import :: c_int
+ logical(c_int) :: C_true ! { dg-warning "C kind type parameter is for type INTEGER but type at .1. is LOGICAL" }
+ end function C_true
+ end interface
+
+ if (c_int == c_bool) stop
+
+ result = C_true()
+ if (result .neqv. .true.) call abort ()
+ if (transfer(result, 0) /= 1) call abort()
+
+ result = .not.C_true()
+ if (transfer(result, 0) /= 0) call abort()
+ if (result .neqv. .false.) call abort ()
+end program main
diff --git a/gcc/testsuite/gfortran.dg/bind_c_bool_2_c.c b/gcc/testsuite/gfortran.dg/bind_c_bool_2_c.c
new file mode 100644
index 0000000..3673bdc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/bind_c_bool_2_c.c
@@ -0,0 +1,7 @@
+/* To be used by bind_c_bool_2.f90. PR fortran/55758 */
+
+int
+C_true (void)
+{
+ return -1;
+}
diff --git a/gcc/testsuite/gfortran.dg/do_5.f90 b/gcc/testsuite/gfortran.dg/do_5.f90
index 08cd8e6..9272d87 100644
--- a/gcc/testsuite/gfortran.dg/do_5.f90
+++ b/gcc/testsuite/gfortran.dg/do_5.f90
@@ -15,7 +15,7 @@
L = .FALSE.
END FUNCTION
- LOGICAL(8) FUNCTION L2() BIND(C)
+ LOGICAL(8) FUNCTION L2() BIND(C) ! { dg-error "GNU Extension: LOGICAL result variable 'l2' at .1. with non-C_Bool kind in BIND.C. procedure 'l2'" }
L2 = .FALSE._8
END FUNCTION
