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 <a name="Option-properties"></a>
 <div class="header">
 <p>
 Previous: <a href="Option-file-format.html#Option-file-format" accesskey="p" rel="prev">Option file format</a>, Up: <a href="Options.html#Options" accesskey="u" rel="up">Options</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
 </div>
 <hr>
 <a name="Option-properties-1"></a>
 <h3 class="section">8.2 Option properties</h3>

 <p>The second field of an option record can specify any of the following
 properties.  When an option takes an argument, it is enclosed in parentheses
 following the option property name.  The parser that handles option files
 is quite simplistic, and will be tricked by any nested parentheses within
 the argument text itself; in this case, the entire option argument can
 be wrapped in curly braces within the parentheses to demarcate it, e.g.:
 </p>
 <div class="smallexample">
 <pre class="smallexample">Condition({defined (USE_CYGWIN_LIBSTDCXX_WRAPPERS)})
 </pre></div>

 <dl compact="compact">
 <dt><code>Common</code></dt>
 <dd><p>The option is available for all languages and targets.
 </p>
 </dd>
 <dt><code>Target</code></dt>
 <dd><p>The option is available for all languages but is target-specific.
 </p>
 </dd>
 <dt><code>Driver</code></dt>
 <dd><p>The option is handled by the compiler driver using code not shared
 with the compilers proper (<samp>cc1</samp> etc.).
 </p>
 </dd>
 <dt><code><var>language</var></code></dt>
 <dd><p>The option is available when compiling for the given language.
 </p>
 <p>It is possible to specify several different languages for the same
 option.  Each <var>language</var> must have been declared by an earlier
 <code>Language</code> record.  See <a href="Option-file-format.html#Option-file-format">Option file format</a>.
 </p>
 </dd>
 <dt><code>RejectDriver</code></dt>
 <dd><p>The option is only handled by the compilers proper (<samp>cc1</samp> etc.)
 and should not be accepted by the driver.
 </p>
 </dd>
 <dt><code>RejectNegative</code></dt>
 <dd><p>The option does not have a &ldquo;no-&rdquo; form.  All options beginning with
 &ldquo;f&rdquo;, &ldquo;W&rdquo; or &ldquo;m&rdquo; are assumed to have a &ldquo;no-&rdquo; form unless this
 property is used.
 </p>
 </dd>
 <dt><code>Negative(<var>othername</var>)</code></dt>
 <dd><p>The option will turn off another option <var>othername</var>, which is
 the option name with the leading &ldquo;-&rdquo; removed.  This chain action will
 propagate through the <code>Negative</code> property of the option to be
 turned off.
 </p>
 <p>As a consequence, if you have a group of mutually-exclusive
 options, their <code>Negative</code> properties should form a circular chain.
 For example, if options <samp>-<var>a</var></samp>, <samp>-<var>b</var></samp> and
 <samp>-<var>c</var></samp> are mutually exclusive, their respective <code>Negative</code>
 properties should be &lsquo;<samp>Negative(<var>b</var>)</samp>&rsquo;, &lsquo;<samp>Negative(<var>c</var>)</samp>&rsquo;
 and &lsquo;<samp>Negative(<var>a</var>)</samp>&rsquo;.
 </p>
 </dd>
 <dt><code>Joined</code></dt>
 <dt><code>Separate</code></dt>
 <dd><p>The option takes a mandatory argument.  <code>Joined</code> indicates
 that the option and argument can be included in the same <code>argv</code>
 entry (as with <code>-mflush-func=<var>name</var></code>, for example).
 <code>Separate</code> indicates that the option and argument can be
 separate <code>argv</code> entries (as with <code>-o</code>).  An option is
 allowed to have both of these properties.
 </p>
 </dd>
 <dt><code>JoinedOrMissing</code></dt>
 <dd><p>The option takes an optional argument.  If the argument is given,
 it will be part of the same <code>argv</code> entry as the option itself.
 </p>
 <p>This property cannot be used alongside <code>Joined</code> or <code>Separate</code>.
 </p>
 </dd>
 <dt><code>MissingArgError(<var>message</var>)</code></dt>
 <dd><p>For an option marked <code>Joined</code> or <code>Separate</code>, the message
 <var>message</var> will be used as an error message if the mandatory
 argument is missing; for options without <code>MissingArgError</code>, a
 generic error message is used.  <var>message</var> should contain a single
 &lsquo;<samp>%qs</samp>&rsquo; format, which will be used to format the name of the option
 passed.
 </p>
 </dd>
 <dt><code>Args(<var>n</var>)</code></dt>
 <dd><p>For an option marked <code>Separate</code>, indicate that it takes <var>n</var>
 arguments.  The default is 1.
 </p>
 </dd>
 <dt><code>UInteger</code></dt>
 <dd><p>The option&rsquo;s argument is a non-negative integer.  The option parser
 will check and convert the argument before passing it to the relevant
 option handler.  <code>UInteger</code> should also be used on options like
 <code>-falign-loops</code> where both <code>-falign-loops</code> and
 <code>-falign-loops</code>=<var>n</var> are supported to make sure the saved
 options are given a full integer.
 </p>
 </dd>
 <dt><code>ToLower</code></dt>
 <dd><p>The option&rsquo;s argument should be converted to lowercase as part of
 putting it in canonical form, and before comparing with the strings
 indicated by any <code>Enum</code> property.
 </p>
 </dd>
 <dt><code>NoDriverArg</code></dt>
 <dd><p>For an option marked <code>Separate</code>, the option only takes an
 argument in the compiler proper, not in the driver.  This is for
 compatibility with existing options that are used both directly and
 via <samp>-Wp,</samp>; new options should not have this property.
 </p>
 </dd>
 <dt><code>Var(<var>var</var>)</code></dt>
 <dd><p>The state of this option should be stored in variable <var>var</var>
 (actually a macro for <code>global_options.x_<var>var</var></code>).
 The way that the state is stored depends on the type of option:
 </p>
 <ul>
 <li> If the option uses the <code>Mask</code> or <code>InverseMask</code> properties,
 <var>var</var> is the integer variable that contains the mask.

 </li><li> If the option is a normal on/off switch, <var>var</var> is an integer
 variable that is nonzero when the option is enabled.  The options
 parser will set the variable to 1 when the positive form of the
 option is used and 0 when the &ldquo;no-&rdquo; form is used.

 </li><li> If the option takes an argument and has the <code>UInteger</code> property,
 <var>var</var> is an integer variable that stores the value of the argument.

 </li><li> If the option takes an argument and has the <code>Enum</code> property,
 <var>var</var> is a variable (type given in the <code>Type</code> property of the
 &lsquo;<samp>Enum</samp>&rsquo; record whose <code>Name</code> property has the same argument as
 the <code>Enum</code> property of this option) that stores the value of the
 argument.

 </li><li> If the option has the <code>Defer</code> property, <var>var</var> is a pointer to
 a <code>VEC(cl_deferred_option,heap)</code> that stores the option for later
 processing.  (<var>var</var> is declared with type <code>void *</code> and needs
 to be cast to <code>VEC(cl_deferred_option,heap)</code> before use.)

 </li><li> Otherwise, if the option takes an argument, <var>var</var> is a pointer to
 the argument string.  The pointer will be null if the argument is optional
 and wasn&rsquo;t given.
 </li></ul>

 <p>The option-processing script will usually zero-initialize <var>var</var>.
 You can modify this behavior using <code>Init</code>.
 </p>
 </dd>
 <dt><code>Var(<var>var</var>, <var>set</var>)</code></dt>
 <dd><p>The option controls an integer variable <var>var</var> and is active when
 <var>var</var> equals <var>set</var>.  The option parser will set <var>var</var> to
 <var>set</var> when the positive form of the option is used and <code>!<var>set</var></code>
 when the &ldquo;no-&rdquo; form is used.
 </p>
 <p><var>var</var> is declared in the same way as for the single-argument form
 described above.
 </p>
 </dd>
 <dt><code>Init(<var>value</var>)</code></dt>
 <dd><p>The variable specified by the <code>Var</code> property should be statically
 initialized to <var>value</var>.  If more than one option using the same
 variable specifies <code>Init</code>, all must specify the same initializer.
 </p>
 </dd>
 <dt><code>Mask(<var>name</var>)</code></dt>
 <dd><p>The option is associated with a bit in the <code>target_flags</code>
 variable (see <a href="Run_002dtime-Target.html#Run_002dtime-Target">Run-time Target</a>) and is active when that bit is set.
 You may also specify <code>Var</code> to select a variable other than
 <code>target_flags</code>.
 </p>
 <p>The options-processing script will automatically allocate a unique bit
 for the option.  If the option is attached to &lsquo;<samp>target_flags</samp>&rsquo;,
 the script will set the macro <code>MASK_<var>name</var></code> to the appropriate
 bitmask.  It will also declare a <code>TARGET_<var>name</var></code> macro that has
 the value 1 when the option is active and 0 otherwise.  If you use <code>Var</code>
 to attach the option to a different variable, the bitmask macro with be
 called <code>OPTION_MASK_<var>name</var></code>.
 </p>
 </dd>
 <dt><code>InverseMask(<var>othername</var>)</code></dt>
 <dt><code>InverseMask(<var>othername</var>, <var>thisname</var>)</code></dt>
 <dd><p>The option is the inverse of another option that has the
 <code>Mask(<var>othername</var>)</code> property.  If <var>thisname</var> is given,
 the options-processing script will declare a <code>TARGET_<var>thisname</var></code>
 macro that is 1 when the option is active and 0 otherwise.
 </p>
 </dd>
 <dt><code>Enum(<var>name</var>)</code></dt>
 <dd><p>The option&rsquo;s argument is a string from the set of strings associated
 with the corresponding &lsquo;<samp>Enum</samp>&rsquo; record.  The string is checked and
 converted to the integer specified in the corresponding
 &lsquo;<samp>EnumValue</samp>&rsquo; record before being passed to option handlers.
 </p>
 </dd>
 <dt><code>Defer</code></dt>
 <dd><p>The option should be stored in a vector, specified with <code>Var</code>,
 for later processing.
 </p>
 </dd>
 <dt><code>Alias(<var>opt</var>)</code></dt>
 <dt><code>Alias(<var>opt</var>, <var>arg</var>)</code></dt>
 <dt><code>Alias(<var>opt</var>, <var>posarg</var>, <var>negarg</var>)</code></dt>
 <dd><p>The option is an alias for <samp>-<var>opt</var></samp> (or the negative form
 of that option, depending on <code>NegativeAlias</code>).  In the first form,
 any argument passed to the alias is considered to be passed to
 <samp>-<var>opt</var></samp>, and <samp>-<var>opt</var></samp> is considered to be
 negated if the alias is used in negated form.  In the second form, the
 alias may not be negated or have an argument, and <var>posarg</var> is
 considered to be passed as an argument to <samp>-<var>opt</var></samp>.  In the
 third form, the alias may not have an argument, if the alias is used
 in the positive form then <var>posarg</var> is considered to be passed to
 <samp>-<var>opt</var></samp>, and if the alias is used in the negative form
 then <var>negarg</var> is considered to be passed to <samp>-<var>opt</var></samp>.
 </p>
 <p>Aliases should not specify <code>Var</code> or <code>Mask</code> or
 <code>UInteger</code>.  Aliases should normally specify the same languages
 as the target of the alias; the flags on the target will be used to
 determine any diagnostic for use of an option for the wrong language,
 while those on the alias will be used to identify what command-line
 text is the option and what text is any argument to that option.
 </p>
 <p>When an <code>Alias</code> definition is used for an option, driver specs do
 not need to handle it and no &lsquo;<samp>OPT_</samp>&rsquo; enumeration value is defined
 for it; only the canonical form of the option will be seen in those
 places.
 </p>
 </dd>
 <dt><code>NegativeAlias</code></dt>
 <dd><p>For an option marked with <code>Alias(<var>opt</var>)</code>, the option is
 considered to be an alias for the positive form of <samp>-<var>opt</var></samp>
 if negated and for the negative form of <samp>-<var>opt</var></samp> if not
 negated.  <code>NegativeAlias</code> may not be used with the forms of
 <code>Alias</code> taking more than one argument.
 </p>
 </dd>
 <dt><code>Ignore</code></dt>
 <dd><p>This option is ignored apart from printing any warning specified using
 <code>Warn</code>.  The option will not be seen by specs and no &lsquo;<samp>OPT_</samp>&rsquo;
 enumeration value is defined for it.
 </p>
 </dd>
 <dt><code>SeparateAlias</code></dt>
 <dd><p>For an option marked with <code>Joined</code>, <code>Separate</code> and
 <code>Alias</code>, the option only acts as an alias when passed a separate
 argument; with a joined argument it acts as a normal option, with an
 &lsquo;<samp>OPT_</samp>&rsquo; enumeration value.  This is for compatibility with the
 Java <samp>-d</samp> option and should not be used for new options.
 </p>
 </dd>
 <dt><code>Warn(<var>message</var>)</code></dt>
 <dd><p>If this option is used, output the warning <var>message</var>.
 <var>message</var> is a format string, either taking a single operand with
 a &lsquo;<samp>%qs</samp>&rsquo; format which is the option name, or not taking any
 operands, which is passed to the &lsquo;<samp>warning</samp>&rsquo; function.  If an alias
 is marked <code>Warn</code>, the target of the alias must not also be marked
 <code>Warn</code>.
 </p>
 </dd>
 <dt><code>Report</code></dt>
 <dd><p>The state of the option should be printed by <samp>-fverbose-asm</samp>.
 </p>
 </dd>
 <dt><code>Warning</code></dt>
 <dd><p>This is a warning option and should be shown as such in
 <samp>--help</samp> output.  This flag does not currently affect anything
 other than <samp>--help</samp>.
 </p>
 </dd>
 <dt><code>Optimization</code></dt>
 <dd><p>This is an optimization option.  It should be shown as such in
 <samp>--help</samp> output, and any associated variable named using
 <code>Var</code> should be saved and restored when the optimization level is
 changed with <code>optimize</code> attributes.
 </p>
 </dd>
 <dt><code>Undocumented</code></dt>
 <dd><p>The option is deliberately missing documentation and should not
 be included in the <samp>--help</samp> output.
 </p>
 </dd>
 <dt><code>Condition(<var>cond</var>)</code></dt>
 <dd><p>The option should only be accepted if preprocessor condition
 <var>cond</var> is true.  Note that any C declarations associated with the
 option will be present even if <var>cond</var> is false; <var>cond</var> simply
 controls whether the option is accepted and whether it is printed in
 the <samp>--help</samp> output.
 </p>
 </dd>
 <dt><code>Save</code></dt>
 <dd><p>Build the <code>cl_target_option</code> structure to hold a copy of the
 option, add the functions <code>cl_target_option_save</code> and
 <code>cl_target_option_restore</code> to save and restore the options.
 </p>
 </dd>
 <dt><code>SetByCombined</code></dt>
 <dd><p>The option may also be set by a combined option such as
 <samp>-ffast-math</samp>.  This causes the <code>gcc_options</code> struct to
 have a field <code>frontend_set_<var>name</var></code>, where <code><var>name</var></code>
 is the name of the field holding the value of this option (without the
 leading <code>x_</code>).  This gives the front end a way to indicate that
 the value has been set explicitly and should not be changed by the
 combined option.  For example, some front ends use this to prevent
 <samp>-ffast-math</samp> and <samp>-fno-fast-math</samp> from changing the
 value of <samp>-fmath-errno</samp> for languages that do not use
 <code>errno</code>.
 </p>
 </dd>
 <dt><code>EnabledBy(<var>opt</var>)</code></dt>
 <dt><code>EnabledBy(<var>opt</var> &amp;&amp; <var>opt2</var>)</code></dt>
 <dd><p>If not explicitly set, the option is set to the value of
 <samp>-<var>opt</var></samp>.  The second form specifies that the option is
 only set if both <var>opt</var> and <var>opt2</var> are set.
 </p>
 </dd>
 <dt><code>LangEnabledBy(<var>language</var>, <var>opt</var>)</code></dt>
 <dt><code>LangEnabledBy(<var>language</var>, <var>opt</var>, <var>posarg</var>, <var>negarg</var>)</code></dt>
 <dd><p>When compiling for the given language, the option is set to the value
 of <samp>-<var>opt</var></samp>, if not explicitly set. In the second form, if
 <var>opt</var> is used in the positive form then <var>posarg</var> is considered
 to be passed to the option, and if <var>opt</var> is used in the negative
 form then <var>negarg</var> is considered to be passed to the option.  It
 is possible to specify several different languages.  Each
 <var>language</var> must have been declared by an earlier <code>Language</code>
 record.  See <a href="Option-file-format.html#Option-file-format">Option file format</a>.
 </p>
 </dd>
 <dt><code>NoDWARFRecord</code></dt>
 <dd><p>The option is omitted from the producer string written by
 <samp>-grecord-gcc-switches</samp>.
 </p>
 </dd>
 <dt><code>PchIgnore</code></dt>
 <dd><p>Even if this is a target option, this option will not be recorded / compared
 to determine if a precompiled header file matches.
 </p></dd>
 </dl>


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	<hr>
	<a name="Option-properties-1"></a>
	<h3 class="section">8.2 Option properties</h3>

	<p>The second field of an option record can specify any of the following
	properties. When an option takes an argument, it is enclosed in parentheses
	following the option property name. The parser that handles option files
	is quite simplistic, and will be tricked by any nested parentheses within
	the argument text itself; in this case, the entire option argument can
	be wrapped in curly braces within the parentheses to demarcate it, e.g.:
	</p>
	<div class="smallexample">
	<pre class="smallexample">Condition({defined (USE_CYGWIN_LIBSTDCXX_WRAPPERS)})
	</pre></div>

	<dl compact="compact">
	<dt><code>Common</code></dt>
	<dd><p>The option is available for all languages and targets.
	</p>
	</dd>
	<dt><code>Target</code></dt>
	<dd><p>The option is available for all languages but is target-specific.
	</p>
	</dd>
	<dt><code>Driver</code></dt>
	<dd><p>The option is handled by the compiler driver using code not shared
	with the compilers proper (<samp>cc1</samp> etc.).
	</p>
	</dd>
	<dt><code><var>language</var></code></dt>
	<dd><p>The option is available when compiling for the given language.
	</p>
	<p>It is possible to specify several different languages for the same
	option. Each <var>language</var> must have been declared by an earlier
	<code>Language</code> record. See <a href="Option-file-format.html#Option-file-format">Option file format</a>.
	</p>
	</dd>
	<dt><code>RejectDriver</code></dt>
	<dd><p>The option is only handled by the compilers proper (<samp>cc1</samp> etc.)
	and should not be accepted by the driver.
	</p>
	</dd>
	<dt><code>RejectNegative</code></dt>
	<dd><p>The option does not have a “no-” form. All options beginning with
	“f”, “W” or “m” are assumed to have a “no-” form unless this
	property is used.
	</p>
	</dd>
	<dt><code>Negative(<var>othername</var>)</code></dt>
	<dd><p>The option will turn off another option <var>othername</var>, which is
	the option name with the leading “-” removed. This chain action will
	propagate through the <code>Negative</code> property of the option to be
	turned off.
	</p>
	<p>As a consequence, if you have a group of mutually-exclusive
	options, their <code>Negative</code> properties should form a circular chain.
	For example, if options <samp>-<var>a</var></samp>, <samp>-<var>b</var></samp> and
	<samp>-<var>c</var></samp> are mutually exclusive, their respective <code>Negative</code>
	properties should be ‘<samp>Negative(<var>b</var>)</samp>’, ‘<samp>Negative(<var>c</var>)</samp>’
	and ‘<samp>Negative(<var>a</var>)</samp>’.
	</p>
	</dd>
	<dt><code>Joined</code></dt>
	<dt><code>Separate</code></dt>
	<dd><p>The option takes a mandatory argument. <code>Joined</code> indicates
	that the option and argument can be included in the same <code>argv</code>
	entry (as with <code>-mflush-func=<var>name</var></code>, for example).
	<code>Separate</code> indicates that the option and argument can be
	separate <code>argv</code> entries (as with <code>-o</code>). An option is
	allowed to have both of these properties.
	</p>
	</dd>
	<dt><code>JoinedOrMissing</code></dt>
	<dd><p>The option takes an optional argument. If the argument is given,
	it will be part of the same <code>argv</code> entry as the option itself.
	</p>
	<p>This property cannot be used alongside <code>Joined</code> or <code>Separate</code>.
	</p>
	</dd>
	<dt><code>MissingArgError(<var>message</var>)</code></dt>
	<dd><p>For an option marked <code>Joined</code> or <code>Separate</code>, the message
	<var>message</var> will be used as an error message if the mandatory
	argument is missing; for options without <code>MissingArgError</code>, a
	generic error message is used. <var>message</var> should contain a single
	‘<samp>%qs</samp>’ format, which will be used to format the name of the option
	passed.
	</p>
	</dd>
	<dt><code>Args(<var>n</var>)</code></dt>
	<dd><p>For an option marked <code>Separate</code>, indicate that it takes <var>n</var>
	arguments. The default is 1.
	</p>
	</dd>
	<dt><code>UInteger</code></dt>
	<dd><p>The option’s argument is a non-negative integer. The option parser
	will check and convert the argument before passing it to the relevant
	option handler. <code>UInteger</code> should also be used on options like
	<code>-falign-loops</code> where both <code>-falign-loops</code> and
	<code>-falign-loops</code>=<var>n</var> are supported to make sure the saved
	options are given a full integer.
	</p>
	</dd>
	<dt><code>ToLower</code></dt>
	<dd><p>The option’s argument should be converted to lowercase as part of
	putting it in canonical form, and before comparing with the strings
	indicated by any <code>Enum</code> property.
	</p>
	</dd>
	<dt><code>NoDriverArg</code></dt>
	<dd><p>For an option marked <code>Separate</code>, the option only takes an
	argument in the compiler proper, not in the driver. This is for
	compatibility with existing options that are used both directly and
	via <samp>-Wp,</samp>; new options should not have this property.
	</p>
	</dd>
	<dt><code>Var(<var>var</var>)</code></dt>
	<dd><p>The state of this option should be stored in variable <var>var</var>
	(actually a macro for <code>global_options.x_<var>var</var></code>).
	The way that the state is stored depends on the type of option:
	</p>
	<ul>
	<li> If the option uses the <code>Mask</code> or <code>InverseMask</code> properties,
	<var>var</var> is the integer variable that contains the mask.

	</li><li> If the option is a normal on/off switch, <var>var</var> is an integer
	variable that is nonzero when the option is enabled. The options
	parser will set the variable to 1 when the positive form of the
	option is used and 0 when the “no-” form is used.

	</li><li> If the option takes an argument and has the <code>UInteger</code> property,
	<var>var</var> is an integer variable that stores the value of the argument.

	</li><li> If the option takes an argument and has the <code>Enum</code> property,
	<var>var</var> is a variable (type given in the <code>Type</code> property of the
	‘<samp>Enum</samp>’ record whose <code>Name</code> property has the same argument as
	the <code>Enum</code> property of this option) that stores the value of the
	argument.

	</li><li> If the option has the <code>Defer</code> property, <var>var</var> is a pointer to
	a <code>VEC(cl_deferred_option,heap)</code> that stores the option for later
	processing. (<var>var</var> is declared with type <code>void *</code> and needs
	to be cast to <code>VEC(cl_deferred_option,heap)</code> before use.)

	</li><li> Otherwise, if the option takes an argument, <var>var</var> is a pointer to
	the argument string. The pointer will be null if the argument is optional
	and wasn’t given.
	</li></ul>

	<p>The option-processing script will usually zero-initialize <var>var</var>.
	You can modify this behavior using <code>Init</code>.
	</p>
	</dd>
	<dt><code>Var(<var>var</var>, <var>set</var>)</code></dt>
	<dd><p>The option controls an integer variable <var>var</var> and is active when
	<var>var</var> equals <var>set</var>. The option parser will set <var>var</var> to
	<var>set</var> when the positive form of the option is used and <code>!<var>set</var></code>
	when the “no-” form is used.
	</p>
	<p><var>var</var> is declared in the same way as for the single-argument form
	described above.
	</p>
	</dd>
	<dt><code>Init(<var>value</var>)</code></dt>
	<dd><p>The variable specified by the <code>Var</code> property should be statically
	initialized to <var>value</var>. If more than one option using the same
	variable specifies <code>Init</code>, all must specify the same initializer.
	</p>
	</dd>
	<dt><code>Mask(<var>name</var>)</code></dt>
	<dd><p>The option is associated with a bit in the <code>target_flags</code>
	variable (see <a href="Run_002dtime-Target.html#Run_002dtime-Target">Run-time Target</a>) and is active when that bit is set.
	You may also specify <code>Var</code> to select a variable other than
	<code>target_flags</code>.
	</p>
	<p>The options-processing script will automatically allocate a unique bit
	for the option. If the option is attached to ‘<samp>target_flags</samp>’,
	the script will set the macro <code>MASK_<var>name</var></code> to the appropriate
	bitmask. It will also declare a <code>TARGET_<var>name</var></code> macro that has
	the value 1 when the option is active and 0 otherwise. If you use <code>Var</code>
	to attach the option to a different variable, the bitmask macro with be
	called <code>OPTION_MASK_<var>name</var></code>.
	</p>
	</dd>
	<dt><code>InverseMask(<var>othername</var>)</code></dt>
	<dt><code>InverseMask(<var>othername</var>, <var>thisname</var>)</code></dt>
	<dd><p>The option is the inverse of another option that has the
	<code>Mask(<var>othername</var>)</code> property. If <var>thisname</var> is given,
	the options-processing script will declare a <code>TARGET_<var>thisname</var></code>
	macro that is 1 when the option is active and 0 otherwise.
	</p>
	</dd>
	<dt><code>Enum(<var>name</var>)</code></dt>
	<dd><p>The option’s argument is a string from the set of strings associated
	with the corresponding ‘<samp>Enum</samp>’ record. The string is checked and
	converted to the integer specified in the corresponding
	‘<samp>EnumValue</samp>’ record before being passed to option handlers.
	</p>
	</dd>
	<dt><code>Defer</code></dt>
	<dd><p>The option should be stored in a vector, specified with <code>Var</code>,
	for later processing.
	</p>
	</dd>
	<dt><code>Alias(<var>opt</var>)</code></dt>
	<dt><code>Alias(<var>opt</var>, <var>arg</var>)</code></dt>
	<dt><code>Alias(<var>opt</var>, <var>posarg</var>, <var>negarg</var>)</code></dt>
	<dd><p>The option is an alias for <samp>-<var>opt</var></samp> (or the negative form
	of that option, depending on <code>NegativeAlias</code>). In the first form,
	any argument passed to the alias is considered to be passed to
	<samp>-<var>opt</var></samp>, and <samp>-<var>opt</var></samp> is considered to be
	negated if the alias is used in negated form. In the second form, the
	alias may not be negated or have an argument, and <var>posarg</var> is
	considered to be passed as an argument to <samp>-<var>opt</var></samp>. In the
	third form, the alias may not have an argument, if the alias is used
	in the positive form then <var>posarg</var> is considered to be passed to
	<samp>-<var>opt</var></samp>, and if the alias is used in the negative form
	then <var>negarg</var> is considered to be passed to <samp>-<var>opt</var></samp>.
	</p>
	<p>Aliases should not specify <code>Var</code> or <code>Mask</code> or
	<code>UInteger</code>. Aliases should normally specify the same languages
	as the target of the alias; the flags on the target will be used to
	determine any diagnostic for use of an option for the wrong language,
	while those on the alias will be used to identify what command-line
	text is the option and what text is any argument to that option.
	</p>
	<p>When an <code>Alias</code> definition is used for an option, driver specs do
	not need to handle it and no ‘<samp>OPT_</samp>’ enumeration value is defined
	for it; only the canonical form of the option will be seen in those
	places.
	</p>
	</dd>
	<dt><code>NegativeAlias</code></dt>
	<dd><p>For an option marked with <code>Alias(<var>opt</var>)</code>, the option is
	considered to be an alias for the positive form of <samp>-<var>opt</var></samp>
	if negated and for the negative form of <samp>-<var>opt</var></samp> if not
	negated. <code>NegativeAlias</code> may not be used with the forms of
	<code>Alias</code> taking more than one argument.
	</p>
	</dd>
	<dt><code>Ignore</code></dt>
	<dd><p>This option is ignored apart from printing any warning specified using
	<code>Warn</code>. The option will not be seen by specs and no ‘<samp>OPT_</samp>’
	enumeration value is defined for it.
	</p>
	</dd>
	<dt><code>SeparateAlias</code></dt>
	<dd><p>For an option marked with <code>Joined</code>, <code>Separate</code> and
	<code>Alias</code>, the option only acts as an alias when passed a separate
	argument; with a joined argument it acts as a normal option, with an
	‘<samp>OPT_</samp>’ enumeration value. This is for compatibility with the
	Java <samp>-d</samp> option and should not be used for new options.
	</p>
	</dd>
	<dt><code>Warn(<var>message</var>)</code></dt>
	<dd><p>If this option is used, output the warning <var>message</var>.
	<var>message</var> is a format string, either taking a single operand with
	a ‘<samp>%qs</samp>’ format which is the option name, or not taking any
	operands, which is passed to the ‘<samp>warning</samp>’ function. If an alias
	is marked <code>Warn</code>, the target of the alias must not also be marked
	<code>Warn</code>.
	</p>
	</dd>
	<dt><code>Report</code></dt>
	<dd><p>The state of the option should be printed by <samp>-fverbose-asm</samp>.
	</p>
	</dd>
	<dt><code>Warning</code></dt>
	<dd><p>This is a warning option and should be shown as such in
	<samp>--help</samp> output. This flag does not currently affect anything
	other than <samp>--help</samp>.
	</p>
	</dd>
	<dt><code>Optimization</code></dt>
	<dd><p>This is an optimization option. It should be shown as such in
	<samp>--help</samp> output, and any associated variable named using
	<code>Var</code> should be saved and restored when the optimization level is
	changed with <code>optimize</code> attributes.
	</p>
	</dd>
	<dt><code>Undocumented</code></dt>
	<dd><p>The option is deliberately missing documentation and should not
	be included in the <samp>--help</samp> output.
	</p>
	</dd>
	<dt><code>Condition(<var>cond</var>)</code></dt>
	<dd><p>The option should only be accepted if preprocessor condition
	<var>cond</var> is true. Note that any C declarations associated with the
	option will be present even if <var>cond</var> is false; <var>cond</var> simply
	controls whether the option is accepted and whether it is printed in
	the <samp>--help</samp> output.
	</p>
	</dd>
	<dt><code>Save</code></dt>
	<dd><p>Build the <code>cl_target_option</code> structure to hold a copy of the
	option, add the functions <code>cl_target_option_save</code> and
	<code>cl_target_option_restore</code> to save and restore the options.
	</p>
	</dd>
	<dt><code>SetByCombined</code></dt>
	<dd><p>The option may also be set by a combined option such as
	<samp>-ffast-math</samp>. This causes the <code>gcc_options</code> struct to
	have a field <code>frontend_set_<var>name</var></code>, where <code><var>name</var></code>
	is the name of the field holding the value of this option (without the
	leading <code>x_</code>). This gives the front end a way to indicate that
	the value has been set explicitly and should not be changed by the
	combined option. For example, some front ends use this to prevent
	<samp>-ffast-math</samp> and <samp>-fno-fast-math</samp> from changing the
	value of <samp>-fmath-errno</samp> for languages that do not use
	<code>errno</code>.
	</p>
	</dd>
	<dt><code>EnabledBy(<var>opt</var>)</code></dt>
	<dt><code>EnabledBy(<var>opt</var> && <var>opt2</var>)</code></dt>
	<dd><p>If not explicitly set, the option is set to the value of
	<samp>-<var>opt</var></samp>. The second form specifies that the option is
	only set if both <var>opt</var> and <var>opt2</var> are set.
	</p>
	</dd>
	<dt><code>LangEnabledBy(<var>language</var>, <var>opt</var>)</code></dt>
	<dt><code>LangEnabledBy(<var>language</var>, <var>opt</var>, <var>posarg</var>, <var>negarg</var>)</code></dt>
	<dd><p>When compiling for the given language, the option is set to the value
	of <samp>-<var>opt</var></samp>, if not explicitly set. In the second form, if
	<var>opt</var> is used in the positive form then <var>posarg</var> is considered
	to be passed to the option, and if <var>opt</var> is used in the negative
	form then <var>negarg</var> is considered to be passed to the option. It
	is possible to specify several different languages. Each
	<var>language</var> must have been declared by an earlier <code>Language</code>
	record. See <a href="Option-file-format.html#Option-file-format">Option file format</a>.
	</p>
	</dd>
	<dt><code>NoDWARFRecord</code></dt>
	<dd><p>The option is omitted from the producer string written by
	<samp>-grecord-gcc-switches</samp>.
	</p>
	</dd>
	<dt><code>PchIgnore</code></dt>
	<dd><p>Even if this is a target option, this option will not be recorded / compared
	to determine if a precompiled header file matches.
	</p></dd>
	</dl>


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