    [NAME]
    ALL.tool.standard.clangdao

    [TITLE]
    ClangDao for Automatic Wrapping

    [DESCRIPTION]

    ClangDao uses the C/C++ frontend of Clang to parse C/C++ header files and generate
    proper wrapping codes for Dao. It has been used successfully to generate a number of
    binding for Dao.

     0.1   Module Definition File

    A configuration or definition file is normally required to wrap a C/C++ library. This
    defintion file should have C source file suffix for C libraries, and C++ source file
    suffix for C++ libraries. In this file, the list of header files for wrapping should be
    included in the standard way. This file may also contain configuration settings and
    wrapping hints. All the configuration settings and wrapping hints should be defined as
    valid C macros.

    For example, the following should be used to set the module name,

       1  #define module_name MyModule
       2  #undef module_name
       3
       4  #include "myModule.h"

    With this, four files will be generated with wrapping codes (where xxx is the suffix of
    the definition file):
      *  dao_MyModule.h:
         This file contains mostly declarations, wrapper structs or classes in case that they
         are need to support function pointer field in struct, and virtual function in C++
         class to allow re-implementation by derived Dao classes.
      *  dao_MyModule.xxx
         This file constains mostly the wrappers for global constant numbers and global
         functions. The entry function for the module is also placed in this file.
      *  dao_MyModule2.xxx
         This file contains mostly type information structures and the wrappers for C++class
         member functions.
      *  dao_MyModule3.xxx
         This file contains mostly re-implemented C++ virtual functions in such a way that,
         when they are executed, they will first check and call Dao re-implementation of the
         virtual functions.

    For C++, proxy classes may be created for wrapping to allow Dao to access the protected
    member methods, to turn off this, the following macro can be defined:

       1  #define CLANGDAO_SKIP_PROTECTED

    Also by default, the functions and types declared in the header files that are not
    directly included the definition file will also be wrapped. To avoid this, the following
    macro can be defined:

       1  #define CLANGDAO_SKIP_EXTERNAL

    Such definition file can be passed to ClangDao as command line argument in the same way
    as passing C/C++ source file to a Clang or GCC compilers. And similarly, option -I can
    be used to specify searching paths for the header files. Example command line,

       1  $ clangdao -Iinclude module_def.cpp

     0.2   Wrapping Hints

    Sometimes C/C++ types are ambiguous from mere type name, for example, for a pointer
    parameter, it is impossible to know if it is a pointer or actually an array. There are
    also other situations where the proper wrapping cannot be inferred from the codes alone.
    To circumvent such problems, wrapping hints can be defined for any function or class that
    need special handling.