r210936 - Copy the documentation of -fstandalone-debug from the man page to the user

[Adrian Prantl]

Author: adrian
Date: Fri Jun 13 16:12:31 2014
New Revision: 210936

URL: http://llvm.org/viewvc/llvm-project?rev=210936&view=rev
Log:
Copy the documentation of -fstandalone-debug from the man page to the user
manual.

rdar://problem/17307006

Modified:
    cfe/trunk/docs/UsersManual.rst

Modified: cfe/trunk/docs/UsersManual.rst
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/UsersManual.rst?rev=210936&r1=210935&r2=210936&view=diff
==============================================================================
--- cfe/trunk/docs/UsersManual.rst (original)
+++ cfe/trunk/docs/UsersManual.rst Fri Jun 13 16:12:31 2014
@@ -1298,6 +1298,22 @@ below. If multiple flags are present, th
   doesn't contain any other data (e.g. description of local variables or
   function parameters).
 
+.. option:: -fstandalone-debug -fno-standalone-debug
+
+  Clang supports a number of optimizations to reduce the size of debug
+  information in the binary. They work based on the assumption that
+  the debug type information can be spread out over multiple
+  compilation units.  For instance, Clang will not emit type
+  definitions for types that are not needed by a module and could be
+  replaced with a forward declaration.  Further, Clang will only emit
+  type info for a dynamic C++ class in the module that contains the
+  vtable for the class.
+
+  The ``-fstandalone-debug`` option turns off these optimizations.
+  This is useful when working with 3rd-party libraries that don't come
+  with debug information.  Note that Clang will never emit type
+  information for types that are not referenced at all by the program.
+
 .. option:: -g
 
   Generate complete debug info.