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Tools for Typelibs - xpt_dump & xpt_link
by Chris Cooper <coop@netscape.com>

Now that XPIDL is capable of generating binary type library files (typelibs, or .xpt files) from IDL code, there is a serious need for tools to manipulate these files. Currently, there are two such tools, xpt_dump, which dumps the contents of a typelib to the screen, and xpt_link, which links multiple typelib files together into ONE BIG TYPELIB. Both tools reside in the mozilla/xpcom/typelib/xpt/tools/ directory.

Get there quick:

xpt_dump - the typelib dumper

xpt_dump is a tool for reading binary-format typelib files and dumping their contents to the screen.

Source Code:

mozilla/xpcom/typelib/xpt/tools/xpt_dump.c

Dependencies:

xpt_dump requires both nspr (NetScape's Portable Runtime, headers only) and libxpt (library of functions for handling type library files).

Command Syntax:

Usage: xpt_dump [-v] filename.xpt
       -v verbose mode

As is visible above, xpt_dump takes one argument, filename.xpt, which must be a valid typelib file. xpt_dump can also take one option flag, -v for verbose mode (which is disabled by default). Sample output for both verbose and non-verbose modes are shown below.

Sample Output:

Command Line: (normal) 
[coop@ivory idl]$ xpt_dump nsISupports.xpt
Output: (normal) 
Header:
   Major version:         1
   Minor version:         0
   Number of interfaces:  1
   Annotations:
      Annotation #0:
         Creator:      xpidl 0.99.1
         Private Data: I should put something here.
 
Interface Directory:
   - ::nsISupports (00000000-0000-0000-c000-000000000046):
      Methods:
         uint32 QueryInterface(in void *, out void *);
     H   uint32 AddRef();
     H   uint32 Release();
      Constants:
         No Constants
Command Line: (verbose) 
[coop@ivory idl]$ xpt_dump -v nsISupports.xpt
Output: (verbose) 
Header:
   Magic beans:           5850434f4d0a547970654c69620d0a1a
                          PASSED
   Major version:         1
   Minor version:         0
   Number of interfaces:  1
   File length:           0
   Data pool offset:      105

   Annotations:
      Annotation #0 is private.
         Creator:      xpidl 0.99.1
         Private Data: I should put something here.
      Annotation #0 is the last annotation.

Interface Directory:
   Interface #0:
      IID:                             00000000-0000-0000-c000-000000000046
      Name:                            nsISupports
      Namespace:                       none
      Address of interface descriptor: 0x804cbf0
      Descriptor:
         # of Method Descriptors:                   3
            Method #0:
               Name:             QueryInterface
               Is Getter?        FALSE
               Is Setter?        FALSE
               Is Varargs?       FALSE
               Is Constructor?   FALSE
               Is Hidden?        FALSE
               # of arguments:   2
               Parameter Descriptors:
                  Parameter #0:
                     In Param?   TRUE
                     Out Param?  FALSE
                     Retval?     FALSE
                     Type Descriptor:
                        Is Pointer?        TRUE
                        Is Unique Pointer? FALSE
                        Is Reference?      FALSE
                        Tag:               13
                  Parameter #1:
                     In Param?   FALSE
                     Out Param?  TRUE
                     Retval?     FALSE
                     Type Descriptor:
                        Is Pointer?        TRUE
                        Is Unique Pointer? FALSE
                        Is Reference?      FALSE
                        Tag:               13
               Result:
                  In Param?   FALSE
                  Out Param?  FALSE
                  Retval?     FALSE
                  Type Descriptor:
                     Is Pointer?        FALSE
                     Is Unique Pointer? FALSE
                     Is Reference?      FALSE
                     Tag:               6
            Method #1:
               Name:             AddRef
               Is Getter?        FALSE
               Is Setter?        FALSE
               Is Varargs?       FALSE
               Is Constructor?   FALSE
               Is Hidden?        TRUE
               # of arguments:   0
               Parameter Descriptors:
               Result:
XXX
                  In Param?   FALSE
                  Out Param?  FALSE
                  Retval?     TRUE
                  Type Descriptor:
                     Is Pointer?        FALSE
                     Is Unique Pointer? FALSE
                     Is Reference?      FALSE
                     Tag:               6
            Method #2:
               Name:             Release
               Is Getter?        FALSE
               Is Setter?        FALSE
               Is Varargs?       FALSE
               Is Constructor?   FALSE
               Is Hidden?        TRUE
               # of arguments:   0
               Parameter Descriptors:
               Result:
XXX
                  In Param?   FALSE
                  Out Param?  FALSE
                  Retval?     TRUE
                  Type Descriptor:
                     Is Pointer?        FALSE
                     Is Unique Pointer? FALSE
                     Is Reference?      FALSE
                     Tag:               6
         Constants:
            No Constants

WARNING: ParamDescriptors are present with bad in/out/retval flag information.
These have been marked with 'XXX'.
Remember, retval params should always be marked as out!

xpt_link - the typelib linker

xpt_link is a tool for linking together multiple binary-format typelib files. The result is ONE BIG TYPELIB containing a single, resolved (in most cases) entry for each interface that appeared in the original typelib files.

Source Code:

mozilla/xpcom/typelib/xpt/tools/xpt_link.c

Dependencies:

xpt_link requires both nspr (NetScape's Portable Runtime, headers only) and libxpt (library of functions for handling type library files).

Command Syntax:

Usage: xpt_link outfile file1.xpt file2.xpt ...
       Links multiple typelib files into one outfile

As is visible above, xpt_link takes at least two arguments. The first argument is the filename of the linked typelib file to be written. The second, third, ...xth arguments are the filenames of valid typelib files. Wildcards (e.g. *.xpt) are acceptable as the second (or any following) argument.

Sample Output:

Command Line: 
[coop@ivory idl]$ xpt_link linked.xpt *.xpt
Output: (if successful) 
File written: linked.xpt
View a dump of linked.xpt created by linking all of the idl files (compiled to typelibs, of course) in the mozilla/xpcom/idl/ directory.
Output: (for a particular failure condition) 
FATAL ERROR:
Duplicate IID detected (adfb3740-aa57-11d2-b7ed-00805f05ffa5) in
interface ::nsIMsgHost from mailnews_base.xpt
and
interface ::nsINNTPHost from mailnews_news.xpt

Chris Cooper
Last modified: Tue Mar 30 19:45:05 EST 1999
Slight fixes by Mike McCabe, Fri May 28 03:52:08 PDT 1999