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
• Source Code
• Dependencies
• Command Syntax
• Sample Output
• xpt_link
• Source Code
• Dependencies
• Command Syntax
• Sample Output

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