[CMake] Add custom command problem ?

[Michael Wild]

On 12/10/2010 09:23 AM, Robert Bielik wrote:
> Hi all,
> 
> Using 2.8.2 I'm trying to make a rule to create a timestamp header, but
> only if a certain file has changed, like so:
> 
> ADD_CUSTOM_COMMAND(
>   OUTPUT src/timestamp.h
>   COMMAND tools/win32/timestamper
>   ARGS src/timestamp.h
>   DEPENDS Version.cmake
>   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
>   COMMENT "Generating timestamp header..."
> )
> 
> but the rule is always executed, even if the Version.cmake file has not
> changed. What am I doing wrong ?
> 
> TIA
> /Rob

1. Always use absolute paths (e.g. using CMAKE_CURRENT_SOURCE_DIR and
CMAKE_CURRENT_BINARY_DIR).

2. Never create output in the source tree.

HTH

Michael