<li><a class="reference internal" href="#hooks-and-environment-variables" id="id17">Hooks and environment variables</a></li>
<li><a class="reference internal" href="#how-plugins-are-loaded" id="id18">How plugins are loaded</a></li>
<li><a class="reference internal" href="#debugging" id="id19">Debugging</a></li>
+<li><a class="reference internal" href="#conditioning-on-the-executable-name" id="id20">Conditioning on the executable name</a></li>
</ul>
</li>
</ul>
$ ./a.out
hello
</pre>
-<p>By default, LLVMC uses <tt class="docutils literal"><span class="pre">llvm-gcc</span></tt> to compile the source code. It is
-also possible to choose the work-in-progress <tt class="docutils literal"><span class="pre">clang</span></tt> compiler with
-the <tt class="docutils literal"><span class="pre">-clang</span></tt> option.</p>
+<p>By default, LLVMC uses <tt class="docutils literal"><span class="pre">llvm-gcc</span></tt> to compile the source code. It is also
+possible to choose the <tt class="docutils literal"><span class="pre">clang</span></tt> compiler with the <tt class="docutils literal"><span class="pre">-clang</span></tt> option.</p>
</div>
<div class="section" id="predefined-options">
<h1><a class="toc-backref" href="#id6">Predefined options</a></h1>
<tt class="docutils literal"><span class="pre">--save-temps=obj</span></tt> switch will write files into the directory specified with
the <tt class="docutils literal"><span class="pre">-o</span></tt> option. The <tt class="docutils literal"><span class="pre">--save-temps=cwd</span></tt> and <tt class="docutils literal"><span class="pre">--save-temps</span></tt> switches are
both synonyms for the default behaviour.</li>
+<li><tt class="docutils literal"><span class="pre">--temp-dir</span> <span class="pre">DIRECTORY</span></tt> - Store temporary files in the given directory. This
+directory is deleted on exit unless <tt class="docutils literal"><span class="pre">--save-temps</span></tt> is specified. If
+<tt class="docutils literal"><span class="pre">--save-temps=obj</span></tt> is also specified, <tt class="docutils literal"><span class="pre">--temp-dir</span></tt> is given the
+precedence.</li>
<li><tt class="docutils literal"><span class="pre">--check-graph</span></tt> - Check the compilation for common errors like mismatched
output/input language names, multiple default edges and cycles. Because of
plugins, these checks can't be performed at compile-time. Exit with code zero
<tt class="docutils literal"><span class="pre">-std=c99</span></tt>. It is also allowed to use spaces instead of the equality
sign: <tt class="docutils literal"><span class="pre">-std</span> <span class="pre">c99</span></tt>. At most one occurrence is allowed.</li>
<li><tt class="docutils literal"><span class="pre">parameter_list_option</span></tt> - same as the above, but more than one option
-occurence is allowed.</li>
+occurrence is allowed.</li>
<li><tt class="docutils literal"><span class="pre">prefix_option</span></tt> - same as the parameter_option, but the option name and
argument do not have to be separated. Example: <tt class="docutils literal"><span class="pre">-ofile</span></tt>. This can be also
specified as <tt class="docutils literal"><span class="pre">-o</span> <span class="pre">file</span></tt>; however, <tt class="docutils literal"><span class="pre">-o=file</span></tt> will be parsed incorrectly
(<tt class="docutils literal"><span class="pre">=file</span></tt> will be interpreted as option value). At most one occurrence is
allowed.</li>
-<li><tt class="docutils literal"><span class="pre">prefix_list_option</span></tt> - same as the above, but more than one occurence of
+<li><tt class="docutils literal"><span class="pre">prefix_list_option</span></tt> - same as the above, but more than one occurrence of
the option is allowed; example: <tt class="docutils literal"><span class="pre">-lm</span> <span class="pre">-lpthread</span></tt>.</li>
<li><tt class="docutils literal"><span class="pre">alias_option</span></tt> - a special option type for creating aliases. Unlike other
option types, aliases are not allowed to have any properties besides the
special cases). Usage example: <tt class="docutils literal"><span class="pre">(parameter_list_option</span> <span class="pre">"foo",</span> <span class="pre">(multi_val</span>
<span class="pre">3))</span></tt>. Only list options can have this attribute; you can, however, use
the <tt class="docutils literal"><span class="pre">one_or_more</span></tt> and <tt class="docutils literal"><span class="pre">zero_or_one</span></tt> properties.</li>
+<li><tt class="docutils literal"><span class="pre">init</span></tt> - this option has a default value, either a string (if it is a
+parameter), or a boolean (if it is a switch; boolean constants are called
+<tt class="docutils literal"><span class="pre">true</span></tt> and <tt class="docutils literal"><span class="pre">false</span></tt>). List options can't have this attribute. Usage
+examples: <tt class="docutils literal"><span class="pre">(switch_option</span> <span class="pre">"foo",</span> <span class="pre">(init</span> <span class="pre">true))</span></tt>; <tt class="docutils literal"><span class="pre">(prefix_option</span> <span class="pre">"bar",</span>
+<span class="pre">(init</span> <span class="pre">"baz"))</span></tt>.</li>
<li><tt class="docutils literal"><span class="pre">extern</span></tt> - this option is defined in some other plugin, see below.</li>
</ul>
</blockquote>
(switch_option "E", (extern))
...
</pre>
-<p>See also the section on plugin <a class="reference internal" href="#priorities">priorities</a>.</p>
+<p>If an external option has additional attributes besides 'extern', they are
+ignored. See also the section on plugin <a class="reference internal" href="#priorities">priorities</a>.</p>
</div>
</div>
<div class="section" id="conditional-evaluation">
Example: <tt class="docutils literal"><span class="pre">(not_empty</span> <span class="pre">"o")</span></tt>.</li>
<li><tt class="docutils literal"><span class="pre">empty</span></tt> - The opposite of <tt class="docutils literal"><span class="pre">not_empty</span></tt>. Equivalent to <tt class="docutils literal"><span class="pre">(not</span> <span class="pre">(not_empty</span>
<span class="pre">X))</span></tt>. Provided for convenience.</li>
+<li><tt class="docutils literal"><span class="pre">single_input_file</span></tt> - Returns true if there was only one input file
+provided on the command-line. Used without arguments:
+<tt class="docutils literal"><span class="pre">(single_input_file)</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">multiple_input_files</span></tt> - Equivalent to <tt class="docutils literal"><span class="pre">(not</span> <span class="pre">(single_input_file))</span></tt> (the
+case of zero input files is considered an error).</li>
<li><tt class="docutils literal"><span class="pre">default</span></tt> - Always evaluates to true. Should always be the last
test in the <tt class="docutils literal"><span class="pre">case</span></tt> expression.</li>
-<li><tt class="docutils literal"><span class="pre">and</span></tt> - A standard logical combinator that returns true iff all
-of its arguments return true. Used like this: <tt class="docutils literal"><span class="pre">(and</span> <span class="pre">(test1),</span>
-<span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>. Nesting of <tt class="docutils literal"><span class="pre">and</span></tt> and <tt class="docutils literal"><span class="pre">or</span></tt> is allowed,
-but not encouraged.</li>
-<li><tt class="docutils literal"><span class="pre">or</span></tt> - Another logical combinator that returns true only if any
-one of its arguments returns true. Example: <tt class="docutils literal"><span class="pre">(or</span> <span class="pre">(test1),</span>
-<span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">and</span></tt> - A standard binary logical combinator that returns true iff all of
+its arguments return true. Used like this: <tt class="docutils literal"><span class="pre">(and</span> <span class="pre">(test1),</span> <span class="pre">(test2),</span>
+<span class="pre">...</span> <span class="pre">(testN))</span></tt>. Nesting of <tt class="docutils literal"><span class="pre">and</span></tt> and <tt class="docutils literal"><span class="pre">or</span></tt> is allowed, but not
+encouraged.</li>
+<li><tt class="docutils literal"><span class="pre">or</span></tt> - A binary logical combinator that returns true iff any of its
+arguments returns true. Example: <tt class="docutils literal"><span class="pre">(or</span> <span class="pre">(test1),</span> <span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN))</span></tt>.</li>
+<li><tt class="docutils literal"><span class="pre">not</span></tt> - Standard unary logical combinator that negates its
+argument. Example: <tt class="docutils literal"><span class="pre">(not</span> <span class="pre">(or</span> <span class="pre">(test1),</span> <span class="pre">(test2),</span> <span class="pre">...</span> <span class="pre">(testN)))</span></tt>.</li>
</ul>
</li>
</ul>
dynamically. When invoked with <tt class="docutils literal"><span class="pre">--check-graph</span></tt>, <tt class="docutils literal"><span class="pre">llvmc</span></tt> doesn't
perform any compilation tasks and returns the number of encountered
errors as its status code.</p>
+</div>
+<div class="section" id="conditioning-on-the-executable-name">
+<h2><a class="toc-backref" href="#id20">Conditioning on the executable name</a></h2>
+<p>For now, the executable name (the value passed to the driver in <tt class="docutils literal"><span class="pre">argv[0]</span></tt>) is
+accessible only in the C++ code (i.e. hooks). Use the following code:</p>
+<pre class="literal-block">
+namespace llvmc {
+extern const char* ProgramName;
+}
+
+std::string MyHook() {
+//...
+if (strcmp(ProgramName, "mydriver") == 0) {
+ //...
+
+}
+</pre>
+<p>In general, you're encouraged not to make the behaviour dependent on the
+executable file name, and use command-line switches instead. See for example how
+the <tt class="docutils literal"><span class="pre">Base</span></tt> plugin behaves when it needs to choose the correct linker options
+(think <tt class="docutils literal"><span class="pre">g++</span></tt> vs. <tt class="docutils literal"><span class="pre">gcc</span></tt>).</p>
<hr />
<address>
<a href="http://jigsaw.w3.org/css-validator/check/referer">
<a href="mailto:foldr@codedgers.com">Mikhail Glushenkov</a><br />
<a href="http://llvm.org">LLVM Compiler Infrastructure</a><br />
-Last modified: $Date: 2008-12-11 11:34:48 -0600 (Thu, 11 Dec 2008) $
+Last modified: $Date$
</address></div>
</div>
</div>