macros_misc.sgml

GLib是GTK+和GNOME工程的基础底层核心程序库

<refsect2>
<title><anchor id="G-GNUC-PRINTF-CAPS">G_GNUC_PRINTF()</title>
<programlisting>#define     G_GNUC_PRINTF( format_idx, arg_idx )</programlisting>
<para>
Expands to the GNU C <literal>format</literal> function attribute if the compiler is <command>gcc</command>.
This is used for declaring functions which take a variable number of
arguments, with the same syntax as <function>printf()</function>.
It allows the compiler to type-check the arguments passed to the function.
See the GNU C documentation for details. 
</para>
<informalexample><programlisting>
gint g_snprintf (gchar  *string,
                 gulong       n,
                 gchar const *format,
                 ...) G_GNUC_PRINTF (3, 4);
</programlisting></informalexample><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>format_idx</parameter>&nbsp;:</entry>
<entry>the index of the argument corresponding to the format string.
(The arguments are numbered from 1).
</entry></row>
<row><entry align="right"><parameter>arg_idx</parameter>&nbsp;:</entry>
<entry>the index of the first of the format arguments.


</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-GNUC-SCANF-CAPS">G_GNUC_SCANF()</title>
<programlisting>#define     G_GNUC_SCANF( format_idx, arg_idx )</programlisting>
<para>
Expands to the GNU C <literal>format</literal> function attribute if the compiler is <command>gcc</command>.
This is used for declaring functions which take a variable number of
arguments, with the same syntax as <function><link linkend="scanf">scanf</link>()</function>.
It allows the compiler to type-check the arguments passed to the function.
See the GNU C documentation for details. 
</para><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>format_idx</parameter>&nbsp;:</entry>
<entry>the index of the argument corresponding to the format string.
(The arguments are numbered from 1).
</entry></row>
<row><entry align="right"><parameter>arg_idx</parameter>&nbsp;:</entry>
<entry>the index of the first of the format arguments.


</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-GNUC-FORMAT-CAPS">G_GNUC_FORMAT()</title>
<programlisting>#define     G_GNUC_FORMAT( arg_idx )</programlisting>
<para>
Expands to the GNU C <literal>format_arg</literal> function attribute if the compiler is <command>gcc</command>.
This function attribute specifies that a function takes a format
string for a <function>printf()</function>, <function><link linkend="scanf">scanf</link>()</function>, 
<function><link linkend="strftime">strftime</link>()</function> or <function><link linkend="strfmon">strfmon</link>()</function> style
function and modifies it, so that the result can be passed to a 
<function>printf()</function>, <function><link linkend="scanf">scanf</link>()</function>, 
<function><link linkend="strftime">strftime</link>()</function> or <function><link linkend="strfmon">strfmon</link>()</function> style 
function (with the remaining arguments to the format function the same as 
they would have been for the unmodified string). 
See the GNU C documentation for details. 
</para>
<informalexample><programlisting>
gchar *g_dgettext (gchar *domain_name, gchar *msgid) G_GNUC_FORMAT (2);
</programlisting></informalexample><informaltable pgwide="1" frame="none" role="params">
<tgroup cols="2">
<colspec colwidth="2*">
<colspec colwidth="8*">
<tbody>
<row><entry align="right"><parameter>arg_idx</parameter>&nbsp;:</entry>
<entry>the index of the argument.


</entry></row>
</tbody></tgroup></informaltable></refsect2>
<refsect2>
<title><anchor id="G-GNUC-FUNCTION-CAPS">G_GNUC_FUNCTION</title>
<programlisting>#define     G_GNUC_FUNCTION</programlisting>
<para>
Expands to the GNU C <literal>__FUNCTION__</literal> variable if the 
compiler is <command>gcc</command>, or "" if it isn't. The GNU C 
<literal>__FUNCTION__</literal> variable contains the name of the 
current function. See the GNU C documentation for details. 
</para></refsect2>
<refsect2>
<title><anchor id="G-GNUC-PRETTY-FUNCTION-CAPS">G_GNUC_PRETTY_FUNCTION</title>
<programlisting>#define     G_GNUC_PRETTY_FUNCTION</programlisting>
<para>
Expands to the GNU C <literal>__PRETTY_FUNCTION__</literal> variable 
if the compiler is <command>gcc</command>, or "" if it isn't.
The GNU C <literal>__PRETTY_FUNCTION__</literal> variable contains the 
name of the current function. For a C program this is the same as the 
<literal>__FUNCTION__</literal> variable but for C++ it also includes 
extra information such as the class and function prototype. See the 
GNU C documentation for details. 
</para></refsect2>
<refsect2>
<title><anchor id="G-GNUC-NO-INSTRUMENT-CAPS">G_GNUC_NO_INSTRUMENT</title>
<programlisting>#define     G_GNUC_NO_INSTRUMENT</programlisting>
<para>
Expands to the GNU C <literal>no_instrument_function</literal> function 
attribute if the compiler is <command>gcc</command>. Functions with this 
attribute will not be 
instrumented for profiling, when the compiler is called with the
<option>-finstrument-functions</option> option.
See the GNU C documentation for details. 
</para></refsect2>
<refsect2>
<title><anchor id="G-STRLOC-CAPS">G_STRLOC</title>
<programlisting>#define     G_STRLOC</programlisting>
<para>
Expands to a string identifying the current code position. 
</para></refsect2>
<refsect2>
<title><anchor id="G-GINT16-FORMAT-CAPS">G_GINT16_FORMAT</title>
<programlisting>#define G_GINT16_FORMAT "hi"
</programlisting>
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type <link linkend="gint16">gint16</link>. It is a string literal, but doesn't
include the percent-sign, such that you can add precision and length
modifiers between percent-sign and conversion specifier.
</para>

<para>
<informalexample>
<programlisting>
gint16 in;
gint32 out;
sscanf ("42", "%" G_GINT16_FORMAT, &amp;in)
out = in * 1000;
g_print ("%" G_GINT32_FORMAT, out);
</programlisting>
</informalexample>
</para></refsect2>
<refsect2>
<title><anchor id="G-GUINT16-FORMAT-CAPS">G_GUINT16_FORMAT</title>
<programlisting>#define G_GUINT16_FORMAT "hu"
</programlisting>
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type <link linkend="guint16">guint16</link>. See also <link linkend="G-GINT16-FORMAT-CAPS">G_GINT16_FORMAT</link>.
</para></refsect2>
<refsect2>
<title><anchor id="G-GINT32-FORMAT-CAPS">G_GINT32_FORMAT</title>
<programlisting>#define G_GINT32_FORMAT "i"
</programlisting>
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type <link linkend="gint32">gint32</link>. See also <link linkend="G-GINT16-FORMAT-CAPS">G_GINT16_FORMAT</link>.
</para></refsect2>
<refsect2>
<title><anchor id="G-GUINT32-FORMAT-CAPS">G_GUINT32_FORMAT</title>
<programlisting>#define G_GUINT32_FORMAT "u"
</programlisting>
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type <link linkend="guint32">guint32</link>. See also <link linkend="G-GINT16-FORMAT-CAPS">G_GINT16_FORMAT</link>.
</para></refsect2>
<refsect2>
<title><anchor id="G-GINT64-FORMAT-CAPS">G_GINT64_FORMAT</title>
<programlisting>#define G_GINT64_FORMAT "lli"
</programlisting>
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type <link linkend="gint64">gint64</link>. See also <link linkend="G-GINT16-FORMAT-CAPS">G_GINT16_FORMAT</link>.
</para>

<note>
<para>
Some platforms do not support scanning and printing 64 bit integers,
even though the types are supported. On such platforms <link linkend="G-GINT64-FORMAT-CAPS">G_GINT64_FORMAT</link>
is not defined.
</para>
</note></refsect2>
<refsect2>
<title><anchor id="G-GUINT64-FORMAT-CAPS">G_GUINT64_FORMAT</title>
<programlisting>#define G_GUINT64_FORMAT "llu"
</programlisting>
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type <link linkend="guint64">guint64</link>. See also <link linkend="G-GINT16-FORMAT-CAPS">G_GINT16_FORMAT</link>.
</para>

<note>
<para>
Some platforms do not support scanning and printing 64 bit integers,
even though the types are supported. On such platforms <link linkend="G-GUINT64-FORMAT-CAPS">G_GUINT64_FORMAT</link>
is not defined.
</para>
</note></refsect2>

</refsect1>




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