Hi folks!
Here're patches (based on stable-2.0) to fix this issue according to
proposal 1.
Please review them, I'm going to write a new CFFI parser with nyacc, so
these patches is important for this plan.
Thanks!
On Sat, 2015-01-24 at 11:33 +0100, Ludovic Courtès wrote:
> Mark H Weaver <m...@netris.org> skribis:
>
> > l...@gnu.org (Ludovic Courtès) writes:
> >
> >> Chaos Eternal <chaoseter...@shlug.org> skribis:
> >>
> >>> Proposals to solve this bug:
> >>>
> >>> Proposal 1.
> >>>
> >>> Adding a keyword argument to pointer->procedure, if set to true, the
> >>> generated wrapper will check 'errno' immediately after ffi_call and
> >>> return the errno as second value.
> >>>
> >>> the proposed pointer->procedure maybe like this:
> >>> pointer->procedure return_type func_ptr arg_types #:return-errno
> I agree #1 is now the best option so far.
>
> Ludo’.
>From 88a99af4b5db9096c3cde51c72eb371b6be76754 Mon Sep 17 00:00:00 2001
From: Nala Ginrut <nalagin...@gmail.com>
Date: Thu, 31 Dec 2015 20:27:59 +0800
Subject: [PATCH 1/2] Add option to pointer->procedure to return errno if
necessary
---
libguile/foreign.c | 33 ++++++++++++++++++++++++---------
libguile/foreign.h | 2 +-
2 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/libguile/foreign.c b/libguile/foreign.c
index 29cfc73..6909023 100644
--- a/libguile/foreign.c
+++ b/libguile/foreign.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2010-2015 Free Software Foundation, Inc.
+/* Copyright (C) 2010-2016 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
@@ -85,7 +85,7 @@ null_pointer_error (const char *func_name)
}
-static SCM cif_to_procedure (SCM cif, SCM func_ptr);
+static SCM cif_to_procedure (SCM cif, SCM func_ptr, SCM return_errno);
static SCM pointer_weak_refs = SCM_BOOL_F;
@@ -753,24 +753,29 @@ make_cif (SCM return_type, SCM arg_types, const char *caller)
}
#undef FUNC_NAME
-SCM_DEFINE (scm_pointer_to_procedure, "pointer->procedure", 3, 0, 0,
- (SCM return_type, SCM func_ptr, SCM arg_types),
+SCM_DEFINE (scm_pointer_to_procedure, "pointer->procedure", 3, 1, 0,
+ (SCM return_type, SCM func_ptr, SCM arg_types, SCM return_errno),
"Make a foreign function.\n\n"
"Given the foreign void pointer @var{func_ptr}, its argument and\n"
"return types @var{arg_types} and @var{return_type}, return a\n"
"procedure that will pass arguments to the foreign function\n"
"and return appropriate values.\n\n"
"@var{arg_types} should be a list of foreign types.\n"
- "@code{return_type} should be a foreign type.")
+ "@code{return_type} should be a foreign type.\n"
+ "@var{return_errno} is @code{#f} in default, if set to #t, then\n"
+ "the @var{errno} will be returned as the second value.")
#define FUNC_NAME s_scm_pointer_to_procedure
{
ffi_cif *cif;
SCM_VALIDATE_POINTER (2, func_ptr);
+ if (SCM_UNLIKELY (SCM_UNBNDP (return_errno)))
+ return_errno = SCM_BOOL_F;
+
cif = make_cif (return_type, arg_types, FUNC_NAME);
- return cif_to_procedure (scm_from_pointer (cif, NULL), func_ptr);
+ return cif_to_procedure (scm_from_pointer (cif, NULL), func_ptr, return_errno);
}
#undef FUNC_NAME
@@ -940,7 +945,7 @@ get_objcode_trampoline (unsigned int nargs)
}
static SCM
-cif_to_procedure (SCM cif, SCM func_ptr)
+cif_to_procedure (SCM cif, SCM func_ptr, SCM return_errno)
{
ffi_cif *c_cif;
SCM objcode, table, ret;
@@ -949,7 +954,8 @@ cif_to_procedure (SCM cif, SCM func_ptr)
objcode = get_objcode_trampoline (c_cif->nargs);
table = scm_c_make_vector (2, SCM_UNDEFINED);
- SCM_SIMPLE_VECTOR_SET (table, 0, scm_cons (cif, func_ptr));
+ SCM_SIMPLE_VECTOR_SET (table, 0,
+ scm_cons (cif, scm_cons (func_ptr, return_errno)));
SCM_SIMPLE_VECTOR_SET (table, 1, SCM_BOOL_F); /* name */
ret = scm_make_program (objcode, table, SCM_BOOL_F);
@@ -1116,9 +1122,11 @@ scm_i_foreign_call (SCM foreign, const SCM *argv)
unsigned i;
size_t arg_size;
scm_t_ptrdiff off;
+ SCM return_errno;
cif = SCM_POINTER_VALUE (SCM_CAR (foreign));
- func = SCM_POINTER_VALUE (SCM_CDR (foreign));
+ func = SCM_POINTER_VALUE (SCM_CADR (foreign));
+ return_errno = SCM_CDDR (foreign);
/* Argument pointers. */
args = alloca (sizeof (void *) * cif->nargs);
@@ -1153,9 +1161,16 @@ scm_i_foreign_call (SCM foreign, const SCM *argv)
rvalue = (void *) ROUND_UP ((scm_t_uintptr) data + off,
max (sizeof (void *), cif->rtype->alignment));
+ errno = 0;
/* off we go! */
ffi_call (cif, func, rvalue, args);
+ if (SCM_LIKELY (scm_is_true (return_errno)))
+ {
+ return scm_values (scm_list_2 (pack (cif->rtype, rvalue, 1),
+ scm_from_int (errno)));
+ }
+
return pack (cif->rtype, rvalue, 1);
}
diff --git a/libguile/foreign.h b/libguile/foreign.h
index 41c0b65..8541526 100644
--- a/libguile/foreign.h
+++ b/libguile/foreign.h
@@ -93,7 +93,7 @@ SCM_INTERNAL SCM scm_pointer_to_string (SCM pointer, SCM length, SCM encoding);
*/
SCM_API SCM scm_pointer_to_procedure (SCM return_type, SCM func_ptr,
- SCM arg_types);
+ SCM arg_types, SCM return_errno);
SCM_API SCM scm_procedure_to_pointer (SCM return_type, SCM func_ptr,
SCM arg_types);
SCM_INTERNAL SCM scm_i_foreign_call (SCM foreign, const SCM *argv);
--
1.7.10.4
>From 71151759513f8163e45c328e5bcae8e89ebbf614 Mon Sep 17 00:00:00 2001
From: Nala Ginrut <nalagin...@gmail.com>
Date: Thu, 31 Dec 2015 20:28:36 +0800
Subject: [PATCH 2/2] updated pointer->procedure in document
---
doc/ref/api-foreign.texi | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/doc/ref/api-foreign.texi b/doc/ref/api-foreign.texi
index c2c49ec..9fd09f5 100644
--- a/doc/ref/api-foreign.texi
+++ b/doc/ref/api-foreign.texi
@@ -813,8 +813,8 @@ tightly packed structs and unions by hand. See the code for
Of course, the land of C is not all nouns and no verbs: there are
functions too, and Guile allows you to call them.
-@deffn {Scheme Procedure} pointer->procedure return_type func_ptr arg_types
-@deffnx {C Procedure} scm_pointer_to_procedure (return_type, func_ptr, arg_types)
+@deffn {Scheme Procedure} pointer->procedure return_type func_ptr arg_types [return_errno=#f]
+@deffnx {C Procedure} scm_pointer_to_procedure (return_type, func_ptr, arg_types, return_errno)
Make a foreign function.
Given the foreign void pointer @var{func_ptr}, its argument and
@@ -825,6 +825,9 @@ and return appropriate values.
@var{arg_types} should be a list of foreign types.
@code{return_type} should be a foreign type. @xref{Foreign Types}, for
more information on foreign types.
+@var{return_errno} is @code{#f} in default, if set to @code{#t}, then @var{errno}
+will be returned as the second value.
+
@end deffn
Here is a better definition of @code{(math bessel)}:
--
1.7.10.4
