[CMake] ExternalProject questions

[Michael Wild]

I have to mention that implementing a patching facility in CMake would  
probably be a considerable effort. Perhaps http://www.xmailserver.org/xdiff-lib.html 
  could be of use there. This library would also allow to implement '- 
E diff', although I'm not sure whether that would be useful at all...

Michael

On 26. Nov, 2009, at 22:52 , Hugh Sorby wrote:

> I have nothing to say for 1. and 2. but I also would like to see 3.  
> in CMake.  Currently I am patching some third_party sources to suit  
> my needs and it would be easier for me if patch was added as an  
> CMake -E command.
>
> I was considering making a feature request but since Michael has  
> mentioned it here, I thought I would add my 2 cents worth.
>
> Michael Wild wrote:
>> Hi all
>>
>> I have a few questions concerning the new ExternalProject module  
>> (which, by the way is fantastic and really simplifies my code).
>>
>> 1. From my understanding of the ExternalProject_Add documentation,  
>> shouldn't INSTALL_DIR be passed on the configure-line as - 
>> DCMAKE_INSTALL_PREFIX:PATH=${INSTALL_DIR} when configuring a CMake- 
>> based project? As far as I can tell, <INSTALL_DIR> is never used in  
>> _ep_add_configure_command (and also no other place, although the  
>> ExternalProject_Add_Step does the substitution).
>>
>> 2. Is it possible to have the library produced by  
>> ExternalProject_Add depend on the target created by  
>> ExternalProject_Add? This would greatly simplify dependency  
>> tracking for me.
>>
>> 3. It would be really useful if CMake implemented a '-E patch'  
>> command. In the same line, it would be great if ExternalProject_Add  
>> had a PATCH_FILE <patch> option, which allows one to simply pass it  
>> a patch which applies with -p1 to the source directory.
>>
>> Michael
>>