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| -rw-r--r-- | lib/spack/spack/architecture.py | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/lib/spack/spack/architecture.py b/lib/spack/spack/architecture.py index 41778795c3..45b4cc228d 100644 --- a/lib/spack/spack/architecture.py +++ b/lib/spack/spack/architecture.py @@ -22,6 +22,58 @@ # License along with this program; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ############################################################################## +""" +This module contains all the elements that are required to create an +architecture object. These include, the target processor, the operating system, +and the architecture platform (i.e. cray, darwin, linux, bgq, etc) classes. + +On a multiple architecture machine, the architecture spec field can be set to +build a package against any target and operating system that is present on the +platform. On Cray platforms or any other architecture that has different front and +back end environments, the operating system will determine the method of compiler +detection. + +There are two different types of compiler detection: + 1. Through the $PATH env variable (front-end detection) + 2. Through the tcl module system. (back-end detection) + +Depending on which operating system is specified, the compiler will be detected +using one of those methods. + +For platforms such as linux and darwin, the operating system is autodetected and +the target is set to be x86_64. + +The command line syntax for specifying an architecture is as follows: + + target=<Target name> os=<OperatingSystem name> + +If the user wishes to use the defaults, either target or os can be left out of +the command line and Spack will concretize using the default. These defaults are +set in the 'platforms/' directory which contains the different subclasses for +platforms. If the machine has multiple architectures, the user can +also enter front-end, or fe or back-end or be. These settings will concretize +to their respective front-end and back-end targets and operating systems. +Additional platforms can be added by creating a subclass of Platform +and adding it inside the platform directory. + +Platforms are an abstract class that are extended by subclasses. If the user +wants to add a new type of platform (such as cray_xe), they can create a subclass +and set all the class attributes such as priority, front_target ,back_target, +front_os, back_os. Platforms also contain a priority class attribute. A lower +number signifies higher priority. These numbers are arbitrarily set and can be +changed though often there isn't much need unless a new platform is added and +the user wants that to be detected first. + +Targets are created inside the platform subclasses. Most architecture (like linux, +and darwin) will have only one target (x86_64) but in the case of Cray machines, +there is both a frontend and backend processor. The user can specify which targets +are present on front-end and back-end architecture + +Depending on the platform, operating systems are either auto-detected or are +set. The user can set the front-end and back-end operating setting by the class +attributes front_os and back_os. The operating system as described earlier, will +be responsible for compiler detection. +""" import os from collections import namedtuple import imp |