[CMake] Question about add_custom_command

[David Aldrich]

Hi 

As mentioned before, I am replacing a manually built gnu makefile (for Linux) that builds a library, with CMake.

A required build step is to run an executable called versionInfo that processes all the source files of the library and generates a new source file called SourceFileInfo.cpp. This generated file must be compiled and added to the library. This step must be executed when any library dependency changes (i.e. any other source file changes).

I tried:

add_custom_command (
  TARGET Kernel
  PRE_BUILD
  COMMAND ${CMAKE_SOURCE_DIR}/../VersionInfo/versionInfo ${CMAKE_SOURCE_DIR} KERNEL
  [COMMENT "Building SourceFileInfo.cpp"]
  )                    

add_library(Kernel STATIC
            ErrorHandler.cpp
            EnvVars.cpp
            SourceFileInfo.cpp
            <snip>
            )

The source files are compiled ok, but versionInfo does not run and, because SourceFileInfo.cpp is therefore not found, the script fails.

Am I on the right track?

I read that PRE_BUILD is only supported for Visual Studio 7 or later, but I got no better result with PRE_LINK.
 
Best regards

David