[doc] update README for new options

README.md

@@ -40,16 +40,16 @@ with `.cpp`, `.C`, `.cxx`, `.c++` or `.cc` will be treated as C++ files.
 Files ending with `.ii` will be considered as already pre-processed C++ files.
 
 Options of the plug-in are the following.
-- `-cxx-demangling-full` tells Frama-C to display C++ global 
-  identifiers with their fully-qualified name (e.g. `::A::x`)
-- `-cxx-demangling-short` tells Frama-C to display global 
-  C++ identifiers with their unqualified name (e.g. `x`)
-- `-cxx-keep-mangling` tells Frama-C to display global C++
-  identifiers with the name they have in the C translation (e.g. 
-  `_Z1A1x`, that allows to distinguish between overloaded symbols.
-  This mangled name is computed from the fully-qualified C++ name
-  according to the rules described in the Itanium C++ ABI. Pretty-printing
-  the AST with this option should result in compilable C code.
+- `-cxx-unmangling key` indicates what to do when outputting a C++ symbol name.
+  `key` can be one the following:
+  - `help`: outputs a list of existing `key` with a short description
+  - `fully-qualified`: displays the fully qualified name (e.g. `::A::x`)
+  - `without-qualifier`: only display the unqualified name (e.g. `x`)
+  - `none`: do not any transformation, displays the name as it is stored
+    in Frama-C's AST (e.g. `_Z1A1x`)
+- `-cxx-parseable-output` indicates that the pretty-printed code resulting
+  from the translation should be able to be parsed again by Frama-C.
+  implies `-cxx-unmangling none`
 - `-cxx-cstdlib-path <path>` specifies where to look for standard
   C library headers (default is the path to Frama-C's headers)
 - `-cxx-c++stdlib-path <path>` specifies where to look for
@@ -62,6 +62,12 @@ Options of the plug-in are the following.
   This should only be needed if the front-end as a whole has not been installed
   properly.
 
+Older versions of the plug-in used specific options for unmangling.
+These are now obsolete:
+- `-cxx-demangling-full`: use `-cxx-unmangling fully-qualified`
+- `-cxx-demangling-short`: use `-cxx-unmangling without-qualifier`
+- `-cxx-keep-mangling`: use `-cxx-unmangling none`
+
 In addition, any command-line option taking a function name as
 argument (e.g.  `-main`, `-eva-slevel-function`, ...) will accept a
 fully qualified C++ name (provided it refers to an existing function