Implement the MoreHelp utility that calls a function to printmore help information if the MoreHelp global is not null.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17774 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/CommandLine.cpp b/lib/Support/CommandLine.cpp
index 90afa0d..ad82c84 100644
--- a/lib/Support/CommandLine.cpp
+++ b/lib/Support/CommandLine.cpp
@@ -834,6 +834,12 @@
 //===----------------------------------------------------------------------===//
 // --help and --help-hidden option implementation
 //
+
+// 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;
+
 namespace {
 
 class HelpPrinter {
@@ -907,6 +913,10 @@
     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)();
+
     // Halt the program if help information is printed
     exit(1);
   }