python-single-r1.eclass: Revert "Remove unused PYTHON_TARGETS"

Pushed too many commits.

Signed-off-by: Michał Górny <mgorny@gentoo.org>

diff --git a/eclass/python-single-r1.eclass b/eclass/python-single-r1.eclass
index 4184b6f132bcc4b1310434fefcd8376669840f93..438f25134c345924385bdfda6f47fc7b1e1355ee 100644 (file)
--- a/eclass/python-single-r1.eclass
+++ b/eclass/python-single-r1.eclass
@@ -89,9 +89,9 @@ EXPORT_FUNCTIONS pkg_setup
 #
 # It should be noted that in order to preserve metadata immutability,
 # PYTHON_COMPAT_OVERRIDE does not affect IUSE nor dependencies.
-# The state of PYTHON_SINGLE_TARGET is ignored, and the implementation
-# in PYTHON_COMPAT_OVERRIDE is built instead.  Dependencies need to be
-# satisfied manually.
+# The state of PYTHON_TARGETS and PYTHON_SINGLE_TARGET is ignored,
+# and the implementation in PYTHON_COMPAT_OVERRIDE is built instead.
+# Dependencies need to be satisfied manually.
 #
 # Example:
 # @CODE
@@ -178,8 +178,10 @@ EXPORT_FUNCTIONS pkg_setup
 
 # @ECLASS-VARIABLE: PYTHON_REQUIRED_USE
 # @DESCRIPTION:
-# This is an eclass-generated required-use expression which ensures
-# that exactly one PYTHON_SINGLE_TARGET value has been enabled.
+# This is an eclass-generated required-use expression which ensures the following
+# when more than one python implementation is possible:
+# 1. Exactly one PYTHON_SINGLE_TARGET value has been enabled.
+# 2. The selected PYTHON_SINGLE_TARGET value is enabled in PYTHON_TARGETS.
 #
 # This expression should be utilized in an ebuild by including it in
 # REQUIRED_USE, optionally behind a use flag.
@@ -191,20 +193,23 @@ EXPORT_FUNCTIONS pkg_setup
 #
 # Example value:
 # @CODE
+# python_single_target_python2_7? ( python_targets_python2_7 )
+# python_single_target_python3_3? ( python_targets_python3_3 )
 # ^^ ( python_single_target_python2_7 python_single_target_python3_3 )
 # @CODE
 
 _python_single_set_globals() {
        _python_set_impls
 
+       local flags_mt=( "${_PYTHON_SUPPORTED_IMPLS[@]/#/python_targets_}" )
        local flags=( "${_PYTHON_SUPPORTED_IMPLS[@]/#/python_single_target_}" )
 
        if [[ ${#_PYTHON_SUPPORTED_IMPLS[@]} -eq 1 ]]; then
                # if only one implementation is supported, use IUSE defaults
                # to avoid requesting the user to enable it
-               IUSE="+${flags[0]}"
+               IUSE="+${flags_mt[0]} +${flags[0]}"
        else
-               IUSE="${flags[*]}"
+               IUSE="${flags_mt[*]} ${flags[*]}"
        fi
 
        local requse="^^ ( ${flags[*]} )"
@@ -213,6 +218,11 @@ _python_single_set_globals() {
 
        local deps= i PYTHON_PKG_DEP
        for i in "${_PYTHON_SUPPORTED_IMPLS[@]}"; do
+               # The chosen targets need to be in PYTHON_TARGETS as well.
+               # This is in order to enforce correct dependencies on packages
+               # supporting multiple implementations.
+               requse+=" python_single_target_${i}? ( python_targets_${i} )"
+
                python_export "${i}" PYTHON_PKG_DEP
                # 1) well, python-exec would suffice as an RDEP
                # but no point in making this overcomplex, BDEP doesn't hurt anyone
@@ -480,6 +490,15 @@ python_setup() {
                                die "More than one implementation in PYTHON_SINGLE_TARGET."
                        fi
 
+                       if ! use "python_targets_${impl}"; then
+                               eerror "The implementation chosen as PYTHON_SINGLE_TARGET must be added"
+                               eerror "to PYTHON_TARGETS as well. This is in order to ensure that"
+                               eerror "dependencies are satisfied correctly. We're sorry"
+                               eerror "for the inconvenience."
+                               echo
+                               die "Build target (${impl}) not in PYTHON_TARGETS."
+                       fi
+
                        python_export "${impl}" EPYTHON PYTHON
                        python_wrapper_setup
                fi
@@ -492,7 +511,7 @@ python_setup() {
                eerror
                eerror "${_PYTHON_SUPPORTED_IMPLS[@]}"
                echo
-               die "No supported Python implementation in PYTHON_SINGLE_TARGET."
+               die "No supported Python implementation in PYTHON_SINGLE_TARGET/PYTHON_TARGETS."
        fi
 }