diff options
author | Mark H Weaver <mhw@netris.org> | 2016-01-05 16:30:41 -0500 |
---|---|---|
committer | Andy Wingo <wingo@pobox.com> | 2016-12-18 23:05:15 +0100 |
commit | a396e14cb139eba37eeeea44e745bfc57bd1f37d (patch) | |
tree | d43075401d719e54382525ca09709adbaa517d4a /doc/ref/api-foreign.texi | |
parent | 546eb479b1fc7e3143b05aaeec16175d1cea0e08 (diff) | |
download | guile-a396e14cb139eba37eeeea44e745bfc57bd1f37d.tar.gz |
FFI: Add support for functions that set 'errno'.
Implements wishlist item <https://debbugs.gnu.org/18592>.
Requested by Frank Terbeck <ft@bewatermyfriend.org>.
Based on a proposed patch by Nala Ginrut <nalaginrut@gmail.com>.
Patch ported to 2.2 by Andy Wingo <wingo@pobox.com>.
* libguile/foreign.c (cif_to_procedure): Add 'with_errno' argument.
If true, truncate result to only one return value.
(scm_i_foreign_call): Separate the arguments. Always return errno.
(pointer_to_procedure): New static function.
(scm_pointer_to_procedure_with_errno): New C API function, implemented
in terms of 'pointer_to_procedure'.
(scm_pointer_to_procedure): Reimplement in terms of
'pointer_to_procedure', no longer bound to "pointer->procedure". See
below.
(scm_i_pointer_to_procedure): New C function bound to
"pointer->procedure" which now accepts the optional #:return-errno?
keyword argument, implemented in terms of 'pointer_to_procedure'.
(k_return_errno): New keyword #:return-errno?.
* libguile/foreign.h (scm_pointer_to_procedure_with_errno): Add prototype.
* doc/ref/api-foreign.texi (Dynamic FFI): Adjust documentation.
* libguile/vm-engine.c (foreign-call): Return two values.
Diffstat (limited to 'doc/ref/api-foreign.texi')
-rw-r--r-- | doc/ref/api-foreign.texi | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/doc/ref/api-foreign.texi b/doc/ref/api-foreign.texi index 76614f021..527902209 100644 --- a/doc/ref/api-foreign.texi +++ b/doc/ref/api-foreign.texi @@ -1,7 +1,7 @@ @c -*-texinfo-*- @c This is part of the GNU Guile Reference Manual. -@c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004, 2007, 2008, -@c 2009, 2010, 2011, 2012, 2013, 2014 Free Software Foundation, Inc. +@c Copyright (C) 1996, 1997, 2000-2004, 2007-2014, 2016 +@c Free Software Foundation, Inc. @c See the file guile.texi for copying conditions. @node Foreign Function Interface @@ -813,8 +813,11 @@ 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 Function} scm_pointer_to_procedure (return_type, func_ptr, arg_types) +@deffnx {C Function} scm_pointer_to_procedure_with_errno (return_type, func_ptr, arg_types) + Make a foreign function. Given the foreign void pointer @var{func_ptr}, its argument and @@ -825,6 +828,10 @@ 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. + +If @var{return-errno?} is true, or when calling +@code{scm_pointer_to_procedure_with_errno}, the returned procedure will +return two values, with @code{errno} as the second value. @end deffn Here is a better definition of @code{(math bessel)}: |