--- /dev/null
+<?xml version='1.0'?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+ "docbook/dtd/xml/4.2/docbookx.dtd" [
+<!ENTITY uffi "<application><emphasis>UFFI</emphasis></application>">
+<!ENTITY ffi "<acronym>FFI</acronym>">
+<!ENTITY cmucl "<application>CMUCL</application>">
+<!ENTITY scl "<application>SCL</application>">
+<!ENTITY lw "<application>Lispworks</application>">
+<!ENTITY sbcl "<application>SBCL</application>">
+<!ENTITY openmcl "<application>OpenMCL</application>">
+<!ENTITY mcl "<application>MCL</application>">
+<!ENTITY acl "<application>AllegroCL</application>">
+<!ENTITY cl "<application>ANSI Common Lisp</application>">
+<!ENTITY t "<constant>T</constant>">
+<!ENTITY nil "<constant>NIL</constant>">
+<!ENTITY null "<constant>NULL</constant>">
+<!ENTITY c "<computeroutput>C</computeroutput>">
+<!ENTITY defsystem "<application>defsystem</application>">
+<!ENTITY asdf "<application>ASDF</application>">
+<!ENTITY bookinfo SYSTEM "bookinfo.sgml">
+<!ENTITY preface SYSTEM "preface.sgml">
+<!ENTITY intro SYSTEM "intro.sgml">
+<!ENTITY notes SYSTEM "notes.sgml">
+<!ENTITY ref SYSTEM "ref.sgml">
+<!ENTITY appendix SYSTEM "appendix.sgml">
+<!ENTITY glossary SYSTEM "glossary.sgml">
+]>
+
+<book>
+
+ <bookinfo>
+ <title>&uffi; Reference Guide</title>
+ <author>
+ <firstname>Kevin</firstname>
+ <othername>M.</othername>
+ <surname>Rosenberg</surname>
+ <affiliation>
+ <orgname>Heart Hospital of New Mexico</orgname>
+ <address>
+ <email>kevin@rosenberg.net</email>
+ <street>504 Elm Street N.E.</street>
+ <city>Albuquerque</city>
+ <state>New Mexico</state>
+ <postcode>87102</postcode>
+ </address>
+ </affiliation>
+ </author>
+
+ <printhistory>
+ <simpara>$Id: bookinfo.sgml 7990 2003-10-12 21:26:56Z kevin $</simpara>
+ <simpara>File $Date: 2003-10-12 15:26:56 -0600 (Sun, 12 Oct 2003) $</simpara>
+ </printhistory>
+ <copyright>
+ <year>2002-2003</year>
+ <holder>Kevin M. Rosenberg</holder>
+ </copyright>
+ <legalnotice>
+ <itemizedlist>
+ <listitem>
+ <para>The &uffi; package was designed and
+ written by Kevin M. Rosenberg.
+ </para>
+ </listitem>
+<listitem>
+<para>
+ Permission is granted to copy, distribute and/or modify this document
+ under the terms of the GNU Free Documentation License, Version 1.1
+ or any later version published by the Free Software Foundation;
+ with no Invariant Sections, with the no
+ Front-Cover Texts, and with no Back-Cover Texts.
+ A copy of the license is included in the &uffi; distribution.
+</para>
+</listitem>
+ <listitem>
+ <para><application>Allegro CL</application>® is a registered
+ trademark of Franz Inc.
+ </para>
+ </listitem>
+ <listitem>
+ <para><application>Lispworks</application>® is a registered
+ trademark of Xanalys Inc.
+ </para>
+ </listitem>
+ <listitem>
+ <para><application>Microsoft
+ Windows</application>® is a registered trademark of
+ Microsoft Inc.
+ </para>
+ </listitem>
+ <listitem>
+ <para>Other brand or
+ product names are the registered trademarks or trademarks of
+ their respective holders.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </legalnotice>
+ </bookinfo>
+
+<preface>
+ <title>Preface</title>
+ <para>This reference guide describes the usage and features
+ of &uffi;. The first
+ chapter provides an overview to the design of &uffi;.
+ Following that chapter is the reference section for all user
+ accessible functions of &uffi;. The appendix covers the
+ installation and implementation-specifc features of &uffi;.
+ </para>
+</preface>
+
+
+<chapter>
+ <title>Introduction</title>
+ <sect1>
+ <title>Purpose</title>
+ <para> This reference guide describes
+ &uffi;, a package that provides a cross-implementation
+ interface from Common Lisp to C-language compatible libraries.
+ </para>
+ </sect1>
+
+ <sect1>
+ <title>Background
+ </title>
+ <para>
+ Every Common Lisp implementation has
+ a method for interfacing to C-language compatible
+ libraries. These methods are often termed a
+ <emphasis>Foreign Function Library Interface</emphasis>
+ (&ffi;). Unfortunately, these methods vary widely
+ amongst
+ implementations, thus preventing the writing of a portable FFI to a
+particular C-library.
+ </para>
+ <para>
+ &uffi; gathers a common subset of functionality between Common Lisp
+ implementations. &uffi; wraps this common subset of functionality with
+ it's own syntax and provides macro translation of uffi functions into
+ the specific syntax of supported Common Lisp implementations.
+ </para>
+ <para>
+ Developers who use &uffi; to interface with C libraries will
+ automatically have their code function in each of uffi's supported
+ implementations.
+ </para>
+ </sect1>
+
+ <sect1>
+ <title>Supported Implementations</title>
+ <para>The primary tested and supported platforms for &uffi; are:
+ </para>
+ <itemizedlist mark="opencircle">
+ <listitem><para>&acl; v6.2 on Debian GNU/Linux
+FreeBSD 4.5, Solaris v2.8, and Microsoft Windows XP.</para></listitem>
+ <listitem><para>&lw; v4.2 on Debian GNU/Linux and Microsoft Windows XP.</para></listitem>
+ <listitem><para>&cmucl; 18d on Debian GNU/Linux, FreeBSD 4.5, and Solaris 2.8</para></listitem>
+ <listitem><para>&sbcl; 0.7.8 on Debian GNU/Linux</para></listitem>
+ <listitem><para>&scl; 1.1.1 on Debian GNU/Linux</para></listitem>
+ <listitem><para>&openmcl; 0.13 on Debian GNU/Linux for PowerPC</para></listitem>
+ </itemizedlist>
+ <para>Beta code is included with &uffi; for
+ </para>
+ <itemizedlist mark="opencircle">
+ <listitem><para>&openmcl; and &mcl; with MacOSX</para></listitem>
+ </itemizedlist>
+ </sect1>
+
+ <sect1>
+ <title>Design</title>
+ <sect2>
+ <title>Overview</title>
+ <para>
+ &uffi; was designed as a cross-implementation
+ compatible <emphasis>Foreign Function Interface</emphasis>.
+ Necessarily,
+ only a common subset of functionality can be
+ provided. Likewise, not every optimization for that a specific
+ implementation provides can be supported. Wherever possible,
+ though, implementation-specific optimizations are invoked.
+ </para>
+ </sect2>
+
+ <sect2>
+ <title>Priorities</title>
+ <para>
+ The design of &uffi; is dictated by the order of these priorities:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ Code using &uffi; must operate correctly on all
+ supported implementations.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Take advantage of implementation-specific optimizations. Ideally,
+ there will not a situation where an implementation-specific
+ &ffi; will be chosen due to lack of optimizations in &uffi;.
+ </para>
+ </listitem>
+ <listitem>
+ <para>Provide a simple interface to developers using
+&uffi;. This priority is quite a bit lower than the above priorities.
+This lower priority is manifest by programmers having to pass types in
+pointer and array dereferencing, needing to use
+<constant>cstring</constant> wrapper functions, and the use of
+ensure-char-character and ensure-char-integer functions. My hope is
+that the developer inconvenience will be outweighed by the generation
+of optimized code that is cross-implementation compatible.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </sect2>
+ </sect1>
+
+</chapter>
+
+
+<chapter>
+ <title>Programming Notes</title>
+
+ <sect1>
+ <title>Implementation Specific Notes</title>
+ <para>
+ </para>
+ <sect2>
+ <title>&acl;</title>
+ <para>
+ </para>
+ </sect2>
+ <sect2>
+ <title>&lw;</title>
+ <para>
+ </para>
+ </sect2>
+ <sect2>
+ <title>&cmucl;</title>
+ <para>
+ </para>
+ </sect2>
+ </sect1>
+
+ <sect1>
+ <title>Foreign Object Representation and Access</title>
+ <para> There are two main approaches used to represent foreign
+ objects: an integer that represents an address in memory, and a
+ object that also includes run-time typing. The advantage of
+ run-time typing is the system can dereference pointers and perform
+ array access without those functions requiring a type at the cost
+ of additional overhead to generate and store the run-time
+ typing. The advantage of integer representation, at least for
+ &acl;, is that the compiler can generate inline code to
+ dereference pointers. Further, the overhead of the run-time type
+ information is eliminated. The disadvantage is the program must
+ then supply
+ the type to the functions to dereference objects and array.
+ </para>
+ </sect1>
+
+ <sect1>
+ <title>Optimizing Code Using UFFI</title>
+ <sect2>
+ <title>Background</title>
+ <para>
+ Two implementions have different techniques to optimize
+ (open-code) foreign objects. &acl; can open-code foreign
+ object
+ access if pointers are integers and the type of object is
+ specified in the access function. Thus, &uffi; represents objects
+ in &acl; as integers which don't have type information.
+ </para> <para>
+ &cmucl; works best when keeping objects as typed
+ objects. However, it's compiler can open-code object access when
+ the object type is specified in <function>declare</function>
+ commands and in <varname>:type</varname> specifiers in
+ <function>defstruct</function> and <function>defclass</function>.
+ </para> <para> &lw;, in converse to &acl; and &cmucl; does not do
+ any open coding of object access. &lw;, by default, maintains
+ objects with run-time typing. </para>
+ </sect2>
+ <sect2>
+ <title>Cross-Implementation Optimization</title>
+ <para>
+ To fully optimize across platforms, both explicit type
+ information must be passed to dereferencing of pointers and
+ arrays. Though this optimization only helps with &acl;, &uffi;
+ is designed to require this type information be passed the
+ dereference functions. Second, declarations of type should be
+ made in functions, structures, and classes where foreign
+ objects will be help. This will optimize access for &lw;
+ </para>
+ <para>
+ Here is an example that should both methods being used for
+ maximum cross-implementation optimization:
+ <programlisting>
+(uffi:def-type the-struct-type-def the-struct-type)
+(let ((a-foreign-struct (allocate-foreign-object 'the-struct-type)))
+ (declare 'the-struct-type-def a-foreign-struct)
+ (get-slot-value a-foreign-struct 'the-struct-type 'field-name))
+ </programlisting>
+ </para>
+ </sect2>
+ </sect1>
+
+</chapter>
+
+
+<reference>
+ <title>Declarations</title>
+
+ <partintro>
+ <sect1>
+ <title>Overview</title>
+ <para>Declarations are used to give the compiler optimizing
+ information about foreign types. Currently, only &cmucl;
+ supports declarations. On &acl; and &lw;, these expressions
+ declare the type generically as &t;
+ </para>
+ </sect1>
+ </partintro>
+
+ <refentry id="def-type">
+ <refnamediv>
+ <refname>def-type</refname>
+ <refpurpose>Defines a Common Lisp type.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-type</function> <replaceable>name type</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A symbol naming the type</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A form that is evaluated that specifies the &uffi; type.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>Defines a Common Lisp type based on a &uffi; type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-type char-ptr '(* :char))
+...
+(defun foo (ptr)
+ (declare (type char-ptr ptr))
+ ...
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Defines a new &cl; type.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+ </reference>
+
+
+ <reference>
+ <title>Primitive Types</title>
+ <partintro>
+ <title>Overview</title>
+ <para>
+ Primitive types have a single value, these include
+ characters, numbers, and pointers. They are all symbols in
+ the keyword package.
+ </para>
+ <itemizedlist>
+ <listitem>
+ <para><constant>:char</constant> - Signed 8-bits. A
+dereferenced :char pointer returns an character.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:unsigned-char</constant> - Unsigned 8-bits. A dereferenced :unsigned-char
+pointer returns an character.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:byte</constant> - Signed 8-bits. A
+dereferenced :byte pointer returns an integer.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:unsigned-byte</constant> - Unsigned 8-bits. A
+dereferenced :unsigned-byte pointer returns an integer.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:short</constant> - Signed 16-bits.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:unsigned-short</constant> - Unsigned 16-bits.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:int</constant> - Signed 32-bits.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:unsigned-int</constant> - Unsigned 32-bits.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:long</constant> - Signed 32 or 64 bits, depending upon the platform.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:unsigned-long</constant> - Unsigned 32 or 64 bits, depending upon the platform.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:float</constant> - 32-bit floating point.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:double</constant> - 64-bit floating point.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:cstring</constant> -
+A &null; terminated string used for passing and returning characters strings with a &c; function.
+ </para>
+ </listitem>
+ <listitem>
+ <para><constant>:void</constant> -
+The absence of a value. Used to indicate that a function does not return a value.</para>
+ </listitem>
+ <listitem>
+ <para><constant>:pointer-void</constant> -
+Points to a generic object.</para>
+ </listitem>
+ <listitem>
+ <para><constant>*</constant> - Used to declare a pointer to an object</para>
+ </listitem>
+ </itemizedlist>
+ </partintro>
+
+ <refentry id="def-constant">
+ <refnamediv>
+ <refname>def-constant</refname>
+ <refpurpose>Binds a symbol to a constant.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-constant</function> <replaceable>name value &key export</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A symbol that will be bound to the value.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>value</parameter></term>
+ <listitem>
+ <para>An evaluated form that is bound the the name.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>export</parameter></term>
+ <listitem>
+ <para>When &t;, the name is exported from the current package. The default is &nil;</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ This is a thin wrapper around
+ <function>defconstant</function>. It evaluates at
+ compile-time and optionally exports the symbol from the package.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-constant pi2 (* 2 pi))
+(def-constant exported-pi2 (* 2 pi) :export t)
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Creates a new special variable..</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="def-foreign-type">
+ <refnamediv>
+ <refname>def-foreign-type</refname>
+ <refpurpose>Defines a new foreign type.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsect1>
+ <title>Syntax</title>
+<synopsis>
+ <function>def-foreign-type</function> <replaceable>name type</replaceable>
+</synopsis>
+ </refsect1>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A symbol naming the new foreign type.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>value</parameter></term>
+ <listitem>
+ <para>A form that is not evaluated that defines the new
+foreign type.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>Defines a new foreign type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-foreign-type my-generic-pointer :pointer-void)
+(def-foreign-type a-double-float :double-float)
+(def-foreign-type char-ptr (* :char))
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Defines a new foreign type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="null-char-p">
+ <refnamediv>
+ <refname>null-char-p</refname>
+ <refpurpose>Tests a character for &null; value.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsect1>
+ <title>Syntax</title>
+<synopsis>
+ <function>null-char-p</function> <replaceable>char</replaceable> => <returnvalue>is-null</returnvalue>
+</synopsis>
+ </refsect1>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>char</parameter></term>
+ <listitem>
+ <para>A character or integer.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>is-null</parameter></term>
+ <listitem>
+ <para>A boolean flag indicating if char is a &null; value.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ A predicate testing if a character or integer is &null;. This
+abstracts the difference in implementations where some return a
+<computeroutput>character</computeroutput> and some return a
+<computeroutput>integer</computeroutput> whence dereferencing a
+<computeroutput>C</computeroutput> character pointer.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-array-pointer ca :unsigned-char)
+(let ((fs (convert-to-foreign-string "ab")))
+ (values (null-char-p (deref-array fs 'ca 0))
+ (null-char-p (deref-array fs 'ca 2))))
+=> &nil;
+ &t;
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+ </reference>
+
+ <reference>
+ <title>Aggregate Types</title>
+ <partintro>
+ <title>Overview</title>
+ <para>
+ Aggregate types are comprised of one or more primitive types.
+ </para>
+ </partintro>
+
+ <refentry id="def-enum">
+ <refnamediv>
+ <refname>def-enum</refname>
+ <refpurpose>Defines a &c; enumeration.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-enum</function> <replaceable>name fields &key separator-string</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A symbol that names the enumeration.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>fields</parameter></term>
+ <listitem>
+ <para>A list of field defintions. Each definition can be
+a symbol or a list of two elements. Symbols get assigned a value of the
+current counter which starts at <computeroutput>0</computeroutput> and
+increments by <computeroutput>1</computeroutput> for each subsequent symbol. It the field definition is a list, the first position is the symbol and the second
+position is the value to assign the the symbol. The current counter gets set
+to <computeroutput>1+</computeroutput> this value.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>separator-string</parameter></term>
+ <listitem>
+ <para>A string that governs the creation of constants. The
+default is <computeroutput>"#"</computeroutput>.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Declares a &c; enumeration. It generates constants with integer values for the elements of the enumeration. The symbols for the these constant
+values are created by the <function>concatenation</function> of the
+enumeration name, separator-string, and field symbol. Also creates
+a foreign type with the name <parameter>name</parameter> of type
+<constant>:int</constant>.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-enum abc (:a :b :c))
+;; Creates constants abc#a (1), abc#b (2), abc#c (3) and defines
+;; the foreign type "abc" to be :int
+
+(def-enum efoo (:e1 (:e2 10) :e3) :separator-string "-")
+;; Creates constants efoo-e1 (1), efoo-e2 (10), efoo-e3 (11) and defines
+;; the foreign type efoo to be :int
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Creates a :int foreign type, defines constants.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="def-struct">
+ <refnamediv>
+ <refname>def-struct</refname>
+ <refpurpose>Defines a &c; structure.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-struct</function> <replaceable>name &rest fields</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A symbol that names the structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>fields</parameter></term>
+ <listitem>
+ <para>A variable number of field defintions. Each definition is a list consisting of a symbol naming the field followed by its foreign type.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Declares a structure. A special type is available as a slot
+in the field. It is a pointer that points to an instance of the parent
+structure. It's type is <constant>:pointer-self</constant>.
+
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-struct foo (a :unsigned-int)
+ (b (* :char))
+ (c (:array :int 10))
+ (next :pointer-self))
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Creates a foreign type.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="get-slot-value">
+ <refnamediv>
+ <refname>get-slot-value</refname>
+ <refpurpose>Retrieves a value from a slot of a structure.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>get-slot-value</function> <replaceable>obj type field</replaceable> => <returnvalue>value</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>obj</parameter></term>
+ <listitem>
+ <para>A pointer to foreign structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A name of the foreign structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>field</parameter></term>
+ <listitem>
+ <para>A name of the desired field in foreign structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>value</returnvalue></term>
+ <listitem>
+ <para>The value of the field in the structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Accesses a slot value from a structure.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(get-slot-value foo-ptr 'foo-structure 'field-name)
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="get-slot-pointer">
+ <refnamediv>
+ <refname>get-slot-pointer</refname>
+ <refpurpose>Retrieves a pointer from a slot of a structure.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>get-slot-pointer</function> <replaceable>obj type field</replaceable> => <returnvalue>pointer</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>obj</parameter></term>
+ <listitem>
+ <para>A pointer to foreign structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A name of the foreign structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>field</parameter></term>
+ <listitem>
+ <para>A name of the desired field in foreign structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>pointer</returnvalue></term>
+ <listitem>
+ <para>The value of the field in the structure.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ This is similar to <function>get-slot-value</function>. It
+ is used when the value of a slot is a pointer type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(get-slot-pointer foo-ptr 'foo-structure 'my-char-ptr)
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="def-array-pointer">
+ <refnamediv>
+ <refname>def-array-pointer</refname>
+ <refpurpose>Defines a pointer to a array of type.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-array-pointer</function> <replaceable>name type</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A name of the new foreign type.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>The foreign type of the array elements.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Defines a type tat is a pointer to an array of type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-array-pointer byte-array-pointer :unsigned-char)
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Defines a new foreign type.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="deref-array">
+ <refnamediv>
+ <refname>deref-array</refname>
+ <refpurpose>Deference an array.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>deref-array</function> <replaceable>array type positon</replaceable> => <returnvalue>value</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>array</parameter></term>
+ <listitem>
+ <para>A foreign array.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>The foreign type of the array.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>position</parameter></term>
+ <listitem>
+ <para>An integer specifying the position to retrieve from
+the array.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>value</returnvalue></term>
+ <listitem>
+ <para>The value stored in the position of the array.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Dereferences (retrieves) the value of an array element.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-array-pointer ca :char)
+(let ((fs (convert-to-foreign-string "ab")))
+ (values (null-char-p (deref-array fs 'ca 0))
+ (null-char-p (deref-array fs 'ca 2))))
+=> &nil;
+ &t;
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Notes</title>
+ <para>
+ The TYPE argument is ignored for CL implementations other than
+ AllegroCL. If you want to cast a pointer to another type use
+ WITH-CAST-POINTER together with DEREF-POINTER/DEREF-ARRAY.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="def-union">
+ <refnamediv>
+ <refname>def-union</refname>
+ <refpurpose>Defines a foreign union type.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-union</function> <replaceable>name &rest fields</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A name of the new union type.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>fields</parameter></term>
+ <listitem>
+ <para>A list of fields of the union.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Defines a foreign union type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-union test-union
+ (a-char :char)
+ (an-int :int))
+
+(let ((u (allocate-foreign-object 'test-union))
+ (setf (get-slot-value u 'test-union 'an-int) (+ 65 (* 66 256)))
+ (prog1
+ (ensure-char-character (get-slot-value u 'test-union 'a-char))
+ (free-foreign-object u)))
+=> #\A
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Defines a new foreign type.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+</reference>
+
+<reference>
+ <title>Objects</title>
+<partintro>
+<title>Overview</title>
+ <para>
+ Objects are entities that can allocated, referred to by pointers, and
+can be freed.
+ </para>
+</partintro>
+
+
+ <refentry id="allocate-foreign-object">
+ <refnamediv>
+ <refname>allocate-foreign-object</refname>
+ <refpurpose>Allocates an instance of a foreign object.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>allocate-foreign-object</function> <replaceable>type &optional size</replaceable> => <returnvalue>ptr</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>The type of foreign object to allocate. This parameter is evaluated.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>size</parameter></term>
+ <listitem>
+ <para>An optional size parameter that is evaluated. If specified, allocates and returns an
+array of <parameter>type</parameter> that is <parameter>size</parameter> members long. This parameter is evaluated.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>ptr</returnvalue></term>
+ <listitem>
+ <para>A pointer to the foreign object.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Allocates an instance of a foreign object. It returns a pointer to the object.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-struct ab (a :int) (b :double))
+(allocate-foreign-object 'ab)
+=> #<ptr>
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="free-foreign-object">
+ <refnamediv>
+ <refname>free-foreign-object</refname>
+ <refpurpose>Frees memory that was allocated for a foreign boject.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>free-foreign-object</function> <replaceable>ptr</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>ptr</parameter></term>
+ <listitem>
+ <para>A pointer to the allocated foreign object to free.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Frees the memory used by the allocation of a foreign object.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="with-foreign-object">
+ <refnamediv>
+ <refname>with-foreign-object</refname>
+ <refpurpose>Wraps the allocation of a foreign object around a body of code.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>with-foreign-object</function> <replaceable>(var type) &body body</replaceable> => <returnvalue>form-return</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>var</parameter></term>
+ <listitem>
+ <para>The variable name to bind.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>The type of foreign object to allocate. This parameter is evaluated.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>form-return</returnvalue></term>
+ <listitem>
+ <para>The result of evaluating the <parameter>body</parameter>.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+This function wraps the allocation, binding, and destruction of a foreign object.
+On &cmucl; and
+&lw; platforms the object is stack allocated for efficiency. Benchmarks show that &acl; performs
+much better with static allocation.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(defun gethostname2 ()
+ "Returns the hostname"
+ (uffi:with-foreign-object (name '(:array :unsigned-char 256))
+ (if (zerop (c-gethostname (uffi:char-array-to-pointer name) 256))
+ (uffi:convert-from-foreign-string name)
+ (error "gethostname() failed."))))
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="size-of-foreign-type">
+ <refnamediv>
+ <refname>size-of-foreign-type</refname>
+ <refpurpose>Returns the number of data bytes used by a foreign object type.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>size-of-foreign-type</function> <replaceable>ftype</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>ftype</parameter></term>
+ <listitem>
+ <para>A foreign type specifier. This parameter is evaluated.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Returns the number of data bytes used by a foreign object type. This does not include any Lisp storage overhead.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <para>
+<programlisting>
+(size-of-foreign-object :unsigned-byte)
+=> 1
+(size-of-foreign-object 'my-100-byte-vector-type)
+=> 100
+</programlisting>
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1> <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="pointer-address">
+ <refnamediv>
+ <refname>pointer-address</refname>
+ <refpurpose>Returns the address of a pointer.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>pointer-address</function> <replaceable>ptr</replaceable> => <returnvalue>address</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>ptr</parameter></term>
+ <listitem>
+ <para>A pointer to a foreign object.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>address</parameter></term>
+ <listitem>
+ <para>An integer representing the pointer's address.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Returns the address as an integer of a pointer.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="deref-pointer">
+ <refnamediv>
+ <refname>deref-pointer</refname>
+ <refpurpose>Deferences a pointer.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>deref-pointer</function> <replaceable>ptr type</replaceable> => <returnvalue>value</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>ptr</parameter></term>
+ <listitem>
+ <para>A pointer to a foreign object.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A foreign type of the object being pointed to.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>value</returnvalue></term>
+ <listitem>
+ <para>The value of the object where the pointer points.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Returns the object to which a pointer points.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <para>
+<programlisting>
+(let ((intp (allocate-foreign-object :int)))
+ (setf (deref-pointer intp :int) 10)
+ (prog1
+ (deref-pointer intp :int)
+ (free-foreign-object intp)))
+=> 10
+</programlisting>
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Notes</title>
+ <para>
+ The TYPE argument is ignored for CL implementations other than
+ AllegroCL. If you want to cast a pointer to another type use
+ WITH-CAST-POINTER together with DEREF-POINTER/DEREF-ARRAY.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="ensure-char-character">
+ <refnamediv>
+ <refname>ensure-char-character</refname>
+ <refpurpose>Ensures that a dereferenced <constant>:char</constant> pointer is
+a character.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>ensure-char-character</function> <replaceable>object</replaceable> => <returnvalue>char</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>object</parameter></term>
+ <listitem>
+ <para>Either a character or a integer specifying a character code.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>char</returnvalue></term>
+ <listitem>
+ <para>A character.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Ensures that an objects obtained by dereferencing
+<constant>:char</constant> and <constant>:unsigned-char</constant>
+pointers are a lisp character.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <para>
+<programlisting>
+(let ((fs (convert-to-foreign-string "a")))
+ (prog1
+ (ensure-char-character (deref-pointer fs :char))
+ (free-foreign-object fs)))
+=> #\a
+</programlisting>
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>Depending upon the implementation and what &uffi; expects, this
+macro may signal an error if the object is not a character or
+integer.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="ensure-char-integer">
+ <refnamediv>
+ <refname>ensure-char-integer</refname>
+ <refpurpose>Ensures that a dereferenced <constant>:char</constant> pointer is
+an integer.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>ensure-char-integer</function> <replaceable>object</replaceable> => <returnvalue>int</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>object</parameter></term>
+ <listitem>
+ <para>Either a character or a integer specifying a character code.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>int</returnvalue></term>
+ <listitem>
+ <para>An integer.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Ensures that an object obtained by dereferencing a
+<constant>:char</constant> pointer is an integer.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <para>
+<programlisting>
+(let ((fs (convert-to-foreign-string "a")))
+ (prog1
+ (ensure-char-integer (deref-pointer fs :char))
+ (free-foreign-object fs)))
+=> 96
+</programlisting>
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>Depending upon the implementation and what &uffi; expects, this
+macro may signal an error if the object is not a character or
+integer.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="make-null-pointer">
+ <refnamediv>
+ <refname>make-null-pointer</refname>
+ <refpurpose>Create a &null; pointer.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>make-null-pointer</function> <replaceable>type</replaceable> => <returnvalue>ptr</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A type of object to which the pointer refers.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>ptr</parameter></term>
+ <listitem>
+ <para>The &null; pointer of type <parameter>type</parameter>.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Creates a &null; pointer of a specified type.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="null-pointer-p">
+ <refnamediv>
+ <refname>null-pointer-p</refname>
+ <refpurpose>Tests a pointer for &null; value.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>null-pointer-p</function> <replaceable>ptr</replaceable> => <returnvalue>is-null</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>ptr</parameter></term>
+ <listitem>
+ <para>A foreign object pointer.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>is-null</returnvalue></term>
+ <listitem>
+ <para>The boolean flag.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ A predicate testing if a pointer is has a &null; value.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="null-cstring-pointer">
+ <refnamediv>
+ <refname>+null-cstring-pointer+</refname>
+ <refpurpose>A constant &null; cstring pointer.
+ </refpurpose>
+ <refclass>Constant</refclass>
+ </refnamediv>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ A &null; cstring pointer. This can be used for testing
+if a cstring returned by a function is &null;.
+ </para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="with-cast-pointer">
+ <refnamediv>
+ <refname>with-cast-pointer</refname>
+ <refpurpose>Wraps a body of code with a pointer cast to a new type.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>with-cast-pointer</function> (<replaceable>binding-name ptr type) & body body</replaceable> => <returnvalue>value</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>ptr</parameter></term>
+ <listitem>
+ <para>A pointer to a foreign object.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A foreign type of the object being pointed to.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>value</returnvalue></term>
+ <listitem>
+ <para>The value of the object where the pointer points.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Executes BODY with POINTER cast to be a pointer to type TYPE. If
+ BINDING-NAME is provided the cast pointer will be bound to this
+ name during the execution of BODY. If BINDING-NAME is not provided
+ POINTER must be a name bound to the pointer which should be
+ cast. This name will be bound to the cast pointer during the
+ execution of BODY.
+
+ This is a no-op in AllegroCL but will wrap BODY in a LET form if
+ BINDING-NAME is provided.
+
+ This macro is meant to be used in conjunction with DEREF-POINTER or
+ DEREF-ARRAY. In Allegro CL the "cast" will actually take place in
+ DEREF-POINTER or DEREF-ARRAY.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+(with-foreign-object (size :int)
+ ;; FOO is a foreign function returning a :POINTER-VOID
+ (let ((memory (foo size)))
+ (when (mumble)
+ ;; at this point we know for some reason that MEMORY points
+ ;; to an array of unsigned bytes
+ (with-cast-pointer (memory :unsigned-byte)
+ (dotimes (i (deref-pointer size :int))
+ (do-something-with
+ (deref-array memory '(:array :unsigned-byte) i)))))))
+</programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="def-foreign-var">
+ <refnamediv>
+ <refname>def-foreign-var</refname>
+ <refpurpose>
+Defines a symbol macro to access a variable in foreign code
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-foreign-var</function> <replaceable>name type module</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>
+A string or list specificying the symbol macro's name. If it is a
+ string, that names the foreign variable. A Lisp name is created
+ by translating #\_ to #\- and by converting to upper-case in
+ case-insensitive Lisp implementations. If it is a list, the first
+ item is a string specifying the foreign variable name and the
+ second it is a symbol stating the Lisp name.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>type</parameter></term>
+ <listitem>
+ <para>A foreign type of the foreign variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>module</returnvalue></term>
+ <listitem>
+ <para>
+ A string specifying the module (or library) the foreign variable
+ resides in. (Required by Lispworks)
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+Defines a symbol macro which can be used to access (get and set) the
+value of a variable in foreign code.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <refsect2>
+ <title>C code</title>
+<programlisting>
+ int baz = 3;
+
+ typedef struct {
+ int x;
+ double y;
+ } foo_struct;
+
+ foo_struct the_struct = { 42, 3.2 };
+
+ int foo () {
+ return baz;
+ }
+</programlisting>
+</refsect2>
+<refsect2>
+<title>Lisp code</title>
+<programlisting>
+ (uffi:def-struct foo-struct
+ (x :int)
+ (y :double))
+
+ (uffi:def-function ("foo" foo)
+ ()
+ :returning :int
+ :module "foo")
+
+ (uffi:def-foreign-var ("baz" *baz*) :int "foo")
+ (uffi:def-foreign-var ("the_struct" *the-struct*) foo-struct "foo")
+
+
+*baz*
+ => 3
+
+(incf *baz*)
+ => 4
+
+(foo)
+ => 4
+</programlisting>
+</refsect2>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+</reference>
+
+ <reference>
+ <title>Strings</title>
+<partintro>
+<title>Overview</title>
+<para>
+
+ &uffi; has functions to two types of
+<varname>C</varname>-compatible
+ strings: <emphasis>cstring</emphasis> and
+<emphasis>foreign</emphasis> strings.
+
+cstrings are used <emphasis>only</emphasis> as parameters to and from
+functions. In some implementations a cstring is not a foreign type but
+rather the Lisp string itself. On other platforms a cstring is a newly
+allocated foreign vector for storing characters. The following is an
+example of using cstrings to both send and return a value.
+</para>
+
+<programlisting>
+(uffi:def-function ("getenv" c-getenv)
+ ((name :cstring))
+ :returning :cstring)
+
+(defun my-getenv (key)
+ "Returns an environment variable, or NIL if it does not exist"
+ (check-type key string)
+ (uffi:with-cstring (key-native key)
+ (uffi:convert-from-cstring (c-getenv key-native))))
+</programlisting>
+
+<para> In contrast, foreign strings are always a foreign vector of
+characters which have memory allocated. Thus, if you need to allocate
+memory to hold the return value of a string, you must use a foreign
+string and not a cstring. The following is an example of using a foreign
+string for a return value. </para>
+
+<programlisting>
+(uffi:def-function ("gethostname" c-gethostname)
+ ((name (* :unsigned-char))
+ (len :int))
+ :returning :int)
+
+(defun gethostname ()
+ "Returns the hostname"
+ (let* ((name (uffi:allocate-foreign-string 256))
+ (result-code (c-gethostname name 256))
+ (hostname (when (zerop result-code)
+ (uffi:convert-from-foreign-string name))))
+ (uffi:free-foreign-object name)
+ (unless (zerop result-code)
+ (error "gethostname() failed."))))
+</programlisting>
+
+<para> Foreign functions that return pointers to freshly allocated
+strings should in general not return cstrings, but foreign strings.
+(There is no portable way to release such cstrings from Lisp.) The
+following is an example of handling such a function. </para>
+
+<programlisting>
+(uffi:def-function ("readline" c-readline)
+ ((prompt :cstring))
+ :returning (* :char))
+
+(defun readline (prompt)
+ "Reads a string from console with line-editing."
+ (with-cstring (c-prompt prompt)
+ (let* ((c-str (c-readline c-prompt))
+ (str (convert-from-foreign-string c-str)))
+ (uffi:free-foreign-object c-str)
+ str)))
+</programlisting>
+
+</partintro>
+
+ <refentry id="convert-from-cstring">
+ <refnamediv>
+ <refname>convert-from-cstring</refname>
+ <refpurpose>Converts a cstring to a Lisp string.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>convert-from-cstring</function> <replaceable>cstring</replaceable> => <returnvalue>string</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>cstring</parameter></term>
+ <listitem>
+ <para>A cstring.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>string</returnvalue></term>
+ <listitem>
+ <para>A Lisp string.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Converts a Lisp string to a <constant>cstring</constant>. This is
+most often used when processing the results of a foreign function
+that returns a cstring.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="convert-to-cstring">
+ <refnamediv>
+ <refname>convert-to-cstring</refname>
+ <refpurpose>Converts a Lisp string to a cstring.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>convert-to-cstring</function> <replaceable>string</replaceable> => <returnvalue>cstring</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>string</parameter></term>
+ <listitem>
+ <para>A Lisp string.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>cstring</returnvalue></term>
+ <listitem>
+ <para>A cstring.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Converts a Lisp string to a
+ <varname>cstring</varname>. The
+ <varname>cstring</varname> should be freed with
+ <function>free-cstring</function>.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>On some implementations, this function allocates memory.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="free-cstring">
+ <refnamediv>
+ <refname>free-cstring</refname>
+ <refpurpose>Free memory used by cstring.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>free-cstring</function> <replaceable>cstring</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>cstring</parameter></term>
+ <listitem>
+ <para>A cstring.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Frees any memory possibly allocated by
+ <function>convert-to-cstring</function>. On some implementions, a cstring is just the Lisp string itself.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="with-cstring">
+ <refnamediv>
+ <refname>with-cstring</refname>
+ <refpurpose>Binds a newly created cstring.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>with-cstring</function> <replaceable>(cstring string) {body}</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>cstring</parameter></term>
+ <listitem>
+ <para>A symbol naming the cstring to be created.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>string</parameter></term>
+ <listitem>
+ <para>A Lisp string that will be translated to a cstring.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>body</parameter></term>
+ <listitem>
+ <para>The body of where the cstring will be bound.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Binds a symbol to a cstring created from conversion of a string. Automatically frees the <varname>cstring</varname>.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <para>
+ <programlisting>
+(def-function ("getenv" c-getenv)
+ ((name :cstring))
+ :returning :cstring)
+
+(defun getenv (key)
+ "Returns an environment variable, or NIL if it does not exist"
+ (check-type key string)
+ (with-cstring (key-cstring key)
+ (convert-from-cstring (c-getenv key-cstring))))
+ </programlisting>
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="convert-from-foreign-string">
+ <refnamediv>
+ <refname>convert-from-foreign-string</refname>
+ <refpurpose>Converts a foreign string into a Lisp string.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>convert-from-foreign-string</function> <replaceable>foreign-string &key length null-terminated-p</replaceable> => <returnvalue>string</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>foreign-string</parameter></term>
+ <listitem>
+ <para>A foreign string.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>length</parameter></term>
+ <listitem>
+ <para>The length of the foreign string to
+convert. The default is the length of the string until a &null;
+character is reached.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>null-terminated-p</parameter></term>
+ <listitem>
+ <para>A boolean flag with a default value of &t; When true,
+the string is converted until the first &null; character is reached.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>string</returnvalue></term>
+ <listitem>
+ <para>A Lisp string.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Returns a Lisp string from a foreign string.
+Can translated ASCII and binary strings.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+ <refentry id="convert-to-foreign-string">
+ <refnamediv>
+ <refname>convert-to-foreign-string</refname>
+ <refpurpose>Converts a Lisp string to a foreign string.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>convert-to-foreign-string</function> <replaceable>string</replaceable> => <returnvalue>foreign-string</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>string</parameter></term>
+ <listitem>
+ <para>A Lisp string.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>foreign-string</returnvalue></term>
+ <listitem>
+ <para>A foreign string.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Converts a Lisp string to a foreign string. Memory should be
+ freed with <function>free-foreign-object</function>.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+
+
+ <refentry id="allocate-foreign-string">
+ <refnamediv>
+ <refname>allocate-foreign-string</refname>
+ <refpurpose>Allocates space for a foreign string.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>allocate-foreign-string</function> <replaceable>size &key unsigned</replaceable> => <returnvalue>foreign-string</returnvalue>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>size</parameter></term>
+ <listitem>
+ <para>The size of the space to be allocated in bytes.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>unsigned</parameter></term>
+ <listitem>
+ <para>A boolean flag with a default value of &t;. When true,
+marks the pointer as an <constant>:unsigned-char</constant>.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>foreign-string</returnvalue></term>
+ <listitem>
+ <para>A foreign string which has undefined contents.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>
+ Allocates space for a foreign string. Memory should
+ be freed with <function>free-foreign-object</function>.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ </reference>
+
+ <reference>
+ <title>Functions & Libraries</title>
+
+ <refentry id="def-function">
+ <refnamediv>
+ <refname>def-function</refname>
+ <refpurpose>Declares a function.
+ </refpurpose>
+ <refclass>Macro</refclass>
+ </refnamediv>
+ <refsynopsisdiv>
+ <title>Syntax</title>
+ <synopsis>
+ <function>def-function</function> <replaceable>name args &key module returning</replaceable>
+ </synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>name</parameter></term>
+ <listitem>
+ <para>A string or list specificying the function name. If it is a string, that names the foreign function. A Lisp name is created by translating #\_ to #\- and by converting to upper-case in case-insensitive Lisp implementations. If it is a list, the first item is a string specifying the foreign function name and the second it is a symbol stating the Lisp name.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>args</parameter></term>
+ <listitem>
+ <para>A list of argument declarations. If &nil;, indicates that the function does not take any arguments.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>module</parameter></term>
+ <listitem>
+ <para>A string specifying which module (or library) that the foreign function resides. (Required by Lispworks)</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>returning</returnvalue></term>
+ <listitem>
+ <para>A declaration specifying the result type of the
+foreign function. If <constant>:void</constant> indicates module does not return any value.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>Declares a foreign function.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(def-function "gethostname"
+ ((name (* :unsigned-char))
+ (len :int))
+ :returning :int)
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="load-foreign-library">
+ <refnamediv>
+ <refname>load-foreign-library</refname>
+ <refpurpose>Loads a foreign library.
+ </refpurpose>
+ <refclass>Function</refclass>
+ </refnamediv>
+ <refsect1>
+ <title>Syntax</title>
+<synopsis>
+ <function>load-foreign-library</function> <replaceable>filename &key module supporting-libraries force-load</replaceable> => <returnvalue>success</returnvalue>
+</synopsis>
+ </refsect1>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>filename</parameter></term>
+ <listitem>
+ <para>A string or pathname specifying the library location
+in the filesystem. At least one implementation (&lw;) can not
+accept a logical pathname.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>module</parameter></term>
+ <listitem>
+ <para>A string designating the name of the module to apply
+to functions in this library. (Required for Lispworks)
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>supporting-libraries</parameter></term>
+ <listitem>
+ <para>A list of strings naming the libraries required to
+link the foreign library. (Required by CMUCL)
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>force-load</parameter></term>
+ <listitem>
+ <para>Forces the loading of the library if it has been previously loaded.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>success</returnvalue></term>
+ <listitem>
+ <para>A boolean flag, &t; if the library was able to be
+loaded successfully or if the library has been previously loaded,
+otherwise &nil;.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>Loads a foreign library. Applies a module name to functions
+within the library. Ensures that a library is only loaded once during
+a session. A library can be reloaded by using the <symbol>:force-load</symbol> key.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+ (load-foreign-library #p"/usr/lib/libmysqlclient.so"
+ :module "mysql"
+ :supporting-libraries '("c"))
+ => T
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>Loads the foreign code into the Lisp system.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>Ability to load the file.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+ <refentry id="find-foreign-library">
+ <refnamediv>
+ <refname>find-foreign-library</refname>
+ <refpurpose>Finds a foreign library file.
+ </refpurpose>
+ <refclass>Function</refclass>
+ </refnamediv>
+ <refsect1>
+ <title>Syntax</title>
+<synopsis>
+ <function>find-foreign-library</function> <replaceable>names directories & drive-letters types</replaceable> => <returnvalue>path</returnvalue>
+</synopsis>
+ </refsect1>
+ <refsect1>
+ <title>Arguments and Values</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>names</parameter></term>
+ <listitem>
+ <para>A string or list of strings containing the base name of the library file.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>directories</parameter></term>
+ <listitem>
+ <para>A string or list of strings containing the directory the library file.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>drive-letters</parameter></term>
+ <listitem>
+ <para>A string or list of strings containing the drive letters for the library file.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>types</parameter></term>
+ <listitem>
+ <para>A string or list of strings containing the file type of the library file. Default
+is &nil;. If &nil;, will use a default type based on the currently running implementation.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><returnvalue>path</returnvalue></term>
+ <listitem>
+ <para>A path containing the path found, or &nil; if the library file was not found.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1>
+ <title>Description</title>
+ <para>Finds a foreign library by searching through a number of possible locations. Returns
+the path of the first found file.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <programlisting>
+(find-foreign-library '("libmysqlclient" "libmysql")
+ '("/opt/mysql/lib/mysql/" "/usr/local/lib/" "/usr/lib/" "/mysql/lib/opt/")
+ :types '("so" "dll")
+ :drive-letters '("C" "D" "E"))
+=> #P"D:\\mysql\\lib\\opt\\libmysql.dll"
+ </programlisting>
+ </refsect1>
+ <refsect1>
+ <title>Side Effects</title>
+ <para>None.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Affected by</title>
+ <para>None.</para>
+ </refsect1>
+ <refsect1>
+ <title>Exceptional Situations</title>
+ <para>None.</para>
+ </refsect1>
+ </refentry>
+
+</reference>
+
+
+<appendix>
+ <title>Installation</title>
+ <sect1>
+ <title>Download &uffi;</title>
+ <para>
+You need to download the &uffi; package from its web
+<ulink url="http://uffi.med-info.com"><citetitle>home</citetitle></ulink>.
+You also need to have a copy of &asdf;. If you need a copy of
+&asdf;, it is included in the
+ <ulink
+ url="http://www.sourceforge.net/projects/cclan">
+ <citetitle>CCLAN</citetitle></ulink> package. You can download
+the file <filename>defsystem.lisp</filename> from the CVS
+<ulink url="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/cclan/asdf/asdf.lisp"><citetitle>tree</citetitle></ulink>.
+ </para>
+ </sect1>
+ <sect1>
+ <title>Installation</title>
+ <para>
+ After downloading and installing &asdf;, simply
+ <function>push</function> the
+ directory containing &uffi; into
+ <varname>asdf:*central-registry*</varname> variable. Whenever you
+want to load the &uffi; package, use the function
+ <computeroutput>(asdf:oos 'asdf:load-op :uffi)</computeroutput>.
+ </para>
+ </sect1>
+</appendix>
+
+
+<glossary>
+ <glossentry id="gloss-ffi">
+ <glossterm>Foreign Function Interface
+ <acronym>FFI</acronym>)
+ </glossterm>
+ <glossdef>
+ <para>
+ An interface to a C-compatible library.
+ </para>
+ </glossdef>
+ </glossentry>
+</glossary>
+
+
+
+</book>
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