[ET Trac] [Einstein Toolkit] #1735: support FFTW3_LIBS FFTW3_INC_DIRS FFTW3_LIB_DIRS in FFTW3 ExternalLibrary

[Einstein Toolkit]

#1735: support FFTW3_LIBS FFTW3_INC_DIRS FFTW3_LIB_DIRS in FFTW3 ExternalLibrary
------------------------------------+---------------------------------------
  Reporter:  rhaas                  |       Owner:  eschnett hinder    
      Type:  defect                 |      Status:  reviewed_ok        
  Priority:  major                  |   Milestone:                     
 Component:  EinsteinToolkit thorn  |     Version:  development version
Resolution:                         |    Keywords:  FFTW3              
------------------------------------+---------------------------------------
Changes (by hinder):

  * status:  review => reviewed_ok


Comment:

 I had to go and look up the meaning of this syntax.  The ":" prefix means
 "don't do anything with the return value, just do the side effects of the
 command" (http://stackoverflow.com/questions/7444504/explanation-of-this-
 use-of-the-colon-operator).  The difference between := and = in the
 parameter expansion is that := changes the value if the parameter is unset
 or null, whereas = only changes it if it is unset
 (https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-
 Expansion.html).  I am assuming that the act of declaring the options in
 configuration.ccl causes Cactus to set the variables to null, which
 explains the need for all the changes in the patch.  Assuming I have
 understood this correctly, please apply.

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/1735#comment:3>
Einstein Toolkit <http://einsteintoolkit.org>
The Einstein Toolkit