<refsect1>
<title>Examples</title>
<programlisting>
-(def-array ca :char)
+(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))))
<refentry id="get-slot-value">
<refnamediv>
- <refname>def-slot-value</refname>
+ <refname>get-slot-value</refname>
<refpurpose>Retrieves a value from a slot of a structure.
</refpurpose>
<refclass>Macro</refclass>
</refentry>
- <refentry id="def-array">
+ <refentry id="def-array-pointer">
<refnamediv>
- <refname>def-array</refname>
- <refpurpose>Defines a foreign array type.
+ <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</function> <replaceable>name type</replaceable>
+ <function>def-array-pointer</function> <replaceable>name type</replaceable>
</synopsis>
</refsynopsisdiv>
<refsect1>
<refsect1>
<title>Description</title>
<para>
- Defines a foreign array type.
+ Defines a type tat is a pointer to an array of type.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<programlisting>
-(def-array byte-array :unsigned-char)
+(def-array-pointer byte-array-pointer :unsigned-char)
</programlisting>
</refsect1>
<refsect1>
<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>
<partintro>
<title>Overview</title>
<para>
- Objects are entities that can allocated and freed.
+ Objects are entities that can allocated, referred to by pointers, and
+can be freed.
</para>
</partintro>
<refsynopsisdiv>
<title>Syntax</title>
<synopsis>
- <function>allocate-foreign-object</function> <replaceable>type</replaceable> => <returnvalue>ptr</returnvalue>
+ <function>allocate-foreign-object</function> <replaceable>type &optional size</replaceable> => <returnvalue>ptr</returnvalue>
</synopsis>
</refsynopsisdiv>
<refsect1>
<varlistentry>
<term><parameter>type</parameter></term>
<listitem>
- <para>A type of foreign object to allocate.
+ <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. If specified, allocates and returns an
+array of <parameter>type</parameter> that is <parameter>size</parameter> members long.
</para>
</listitem>
</varlistentry>
</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="pointer-address">
<refnamediv>
<refname>pointer-address</refname>
<refsynopsisdiv>
<title>Syntax</title>
<synopsis>
- <function>def-pointer</function> <replaceable>ptr type</replaceable> => <returnvalue>value</returnvalue>
+ <function>deref-pointer</function> <replaceable>ptr type</replaceable> => <returnvalue>value</returnvalue>
</synopsis>
</refsynopsisdiv>
<refsect1>
</listitem>
</varlistentry>
<varlistentry>
- <term><parameter>value</parameter></term>
+ <term><returnvalue>value</returnvalue></term>
<listitem>
<para>The value of the object where the pointer points.
</para>
<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>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 object obtained by dereferencing a
+<constant>:char</constant> pointer is a character.
+ </para>
+ </refsect1>
+ <refsect1>
+ <title>Examples</title>
+ <para>
+<programlisting>
(let ((fs (convert-to-foreign-string "a")))
(prog1
- (ensure-char (deref-pointer fs :char))
+ (ensure-char-character (deref-pointer fs :char))
(free-foreign-object fs)))
=> #\a
</programlisting>
</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">
<title>Examples</title>
<programlisting>
(def-function "gethostname"
- ((name :cstring)
+ ((name (* :unsigned-char))
(len :int))
:returning :int)
</programlisting>