Johannes Passing's Blog

Although message tables play an important role in Windows, their tool support has always be somewhat limited — at least compared to string tables, for which Visual Studio even provides a graphical editor.

When in comes to creating and embedding message tables into a binary built with the WDK, documentation is light. However, the WDK tool chain provides support for mc files and using it requires only a few steps.

1. Create a message file

Unsurprisingly, the first step is to write a message file — I will name it foobarmsg.mc. Here is an example file:

;
; The default is NTSTATUS -- but HRESULT works just as well.
;
MessageIdTypedef=HRESULT

SeverityNames=(
  Success=0x0
  Informational=0x1
  Warning=0x2
  Error=0x3
)

FacilityNames=(
  Interface=4
)

LanguageNames=(English=0x409:MSG00409)

;//--------------------------------------------------------------------
MessageId		= 0x9000
Severity		= Warning
Facility		= Interface
SymbolicName	= FOOBAR_E_WEIRDFAILURE
Language		= English
Some weird failure has occured.
.

Updating the SOURCES file

The message file must be compiled (done by mc.exe). If we include the mc file in the SOURCES macro, build.exe will arange this for us:

SOURCES=
	foobar.c 
	foobarmsg.mc

To tell mc where to place the result files (i.e. the header and the resources), the following two macros can be used in the SOURCES file:

PASS0_HEADERDIR=....include
PASS0_SOURCEDIR=obj$(BUILD_ALT_DIR)$(TARGET_DIRECTORY)

As the names of the macros suggest, mc.exe is run during pass 0 (i.e. before any sources are compiled) — therefore, it is no problem to include the generated header file (foobar.h) in the source files.

Updating the rc file

Assuming the project already includes a .rc file for versioning information, we can use this file and refer to the generated message table resources. At the end of your project’s rc file, include the following line:

#include "foobarmsg.rc"

That’s it. The resulting binary will contain a proper message table.