pkgs/build-support/setup-hooks/role.bash

   1 # Since the same derivation can be depended on in multiple ways, we need to
   2 # accumulate *each* role (i.e. host and target platforms relative the depending
   3 # derivation) in which the derivation is used.
   4 #
   5 # The role is intended to be used as part of other variables names like
   6 #  - $NIX_SOMETHING${role_post}
   7
   8 function getRole() {
   9     case $1 in
  10         -1)
  11             role_post='_FOR_BUILD'
  12             ;;
  13         0)
  14             role_post=''
  15             ;;
  16         1)
  17             role_post='_FOR_TARGET'
  18             ;;
  19         *)
  20             echo "@name@: used as improper sort of dependency" >&2
  21             return 1
  22             ;;
  23     esac
  24 }
  25
  26 # `hostOffset` describes how the host platform of the package is slid relative
  27 # to the depending package. `targetOffset` likewise describes the target
  28 # platform of the package. Both are brought into scope of the setup hook defined
  29 # for dependency whose setup hook is being processed relative to the package
  30 # being built.
  31
  32 function getHostRole()   {
  33     getRole "$hostOffset"
  34 }
  35 function getTargetRole() {
  36     getRole "$targetOffset"
  37 }
  38
  39 # `depHostOffset` describes how the host platform of the dependencies are slid
  40 # relative to the depending package. `depTargetOffset` likewise describes the
  41 # target platform of dependenices. Both are brought into scope of the
  42 # environment hook defined for the dependency being applied relative to the
  43 # package being built.
  44
  45 function getHostRoleEnvHook()   {
  46     getRole "$depHostOffset"
  47 }
  48 function getTargetRoleEnvHook() {
  49     getRole "$depTargetOffset"
  50 }
  51
  52 # This variant is intended specifically for code-producing tool wrapper scripts
  53 # `NIX_@wrapperName@_TARGET_*_@suffixSalt@` tracks this (needs to be an exported
  54 # env var so can't use fancier data structures).
  55 function getTargetRoleWrapper() {
  56     case $targetOffset in
  57         -1)
  58             export NIX_@wrapperName@_TARGET_BUILD_@suffixSalt@=1
  59             ;;
  60         0)
  61             export NIX_@wrapperName@_TARGET_HOST_@suffixSalt@=1
  62             ;;
  63         1)
  64             export NIX_@wrapperName@_TARGET_TARGET_@suffixSalt@=1
  65             ;;
  66         *)
  67             echo "@name@: used as improper sort of dependency" >&2
  68             return 1
  69             ;;
  70     esac
  71 }