"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
+ <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>CommandLine 2.0 Library Manual</title>
<link rel="stylesheet" href="llvm.css" type="text/css">
</head>
<li><a href="#cl::opt">The <tt>cl::opt</tt> class</a></li>
<li><a href="#cl::list">The <tt>cl::list</tt> class</a></li>
<li><a href="#cl::alias">The <tt>cl::alias</tt> class</a></li>
+ <li><a href="#cl::extrahelp">The <tt>cl::extrahelp</tt> class</a></li>
</ul></li>
<li><a href="#builtinparsers">Builtin parsers</a>
</div>
+<!-- _______________________________________________________________________ -->
+<div class="doc_subsubsection">
+ <a name="cl::extrahelp">The <tt>cl::extrahelp</tt> class</a>
+</div>
+
+<div class="doc_text">
+
+<p>The <tt>cl::extrahelp</tt> class is a nontemplated class that allows extra
+help text to be printed out for the <tt>--help</tt> option.</p>
+
+<pre>
+<b>namespace</b> cl {
+ <b>struct</b> extrahelp;
+}
+</pre>
+
+<p>To use the extrahelp, simply construct one with a <tt>const char*</tt>
+parameter to the constructor. The text passed to the constructor will be printed
+at the bottom of the help message, verbatim. Note that multiple
+<tt>cl::extrahelp</tt> <b>can</b> be used but this practice is discouraged. If
+your tool needs to print additional help information, put all that help into a
+single <tt>cl::extrahelp</tt> instance.</p>
+<p>For example:</p>
+<pre>
+ cl::extrahelp("\nADDITIONAL HELP:\n\n This is the extra help\n");
+</pre>
+</div>
+
<!-- ======================================================================= -->
<div class="doc_subsection">
<a name="builtinparsers">Builtin parsers</a>
void apply(alias &A) const { A.setAliasFor(Opt); }
};
-/// Permit the tool to provide additional help output after the normal
-/// help output. To use this, create a function that returns void and
-/// takes no arguments. Assign its address to cl::MoreHelp. If set,
-/// this function will be called just before the CommandLine exits
-/// after printing the help.
-/// @brief Optional pointer to additional help function
-extern void (*MoreHelp)();
+// extrahelp - provide additional help at the end of the normal help
+// output. All occurrences of cl::extrahelp will be accumulated and
+// printed to std::cerr at the end of the regular help, just before
+// exit is called.
+struct extrahelp {
+ const char * morehelp;
+ extrahelp(const char* help);
+};
+
+// This function just prints the help message, exactly the same way as if the
+// --help option had been given on the command line.
+// NOTE: THIS FUNCTION TERMINATES THE PROGRAM!
+void PrintHelpMessage();
} // End namespace cl
// If this variable is set, it is a pointer to a function that the user wants
// us to call after we print out the help info. Basically a hook to allow
// additional help to be printed.
-void (*cl::MoreHelp)() = 0;
+static std::vector<const char*>* MoreHelp = 0;
+
+extrahelp::extrahelp(const char* Help)
+ : morehelp(Help) {
+ if (!MoreHelp) {
+ MoreHelp = new std::vector<const char*>;
+ }
+ MoreHelp->push_back(Help);
+}
namespace {
for (unsigned i = 0, e = Options.size(); i != e; ++i)
Options[i].second->printOptionInfo(MaxArgLen);
- // Call the user's hook so help output can be extended.
- if (MoreHelp != 0)
- (*MoreHelp)();
+ // Print any extra help the user has declared. If MoreHelp is not null,
+ // then the user used at least one cl::extrahelp instance to provide
+ // additional help. We just print it out now.
+ if (MoreHelp != 0) {
+ for (std::vector<const char *>::iterator I = MoreHelp->begin(),
+ E = MoreHelp->end(); I != E; ++I)
+ std::cerr << *I;
+ }
- // Halt the program if help information is printed
+ // Halt the program since help information was printed
exit(1);
}
};
VersOp("version", cl::desc("display the version"),
cl::location(VersionPrinterInstance), cl::ValueDisallowed);
+
} // End anonymous namespace
+
+// Utility function for printing the help message.
+void cl::PrintHelpMessage() {
+ NormalPrinter = true;
+}
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