Allow limiting accepted implementations in python_setup. This allows
ebuilds to explicitly specify which implementations can be used to
perform specific tasks (e.g. doc build) rather than implicitly relying
on specific implementation preference order.
Example use case:
IUSE="doc"
RDEPEND="doc? ( dev-python/epydoc[$(python_gen_usedep 'python2*')] )"
REQUIRED_USE="doc? ( || ( $(python_gen_useflags 'python2*') ) )"
So far, such ebuilds implicitly assumed Python 2 will be preferred over
Python 3, so if any version of Python 2 is enabled, python_setup will
use it.
With the new API, the src_configure() call could look like:
src_configure() {
#...
if use doc; then
python_setup 'python2*'
./build_docs.py
fi
}
Therefore explicitly restricting the choice to Python 2.* independently
of eclass-defined implementation order/preference.
---
eclass/python-r1.eclass | 45 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 42 insertions(+), 3 deletions(-)
diff --git a/eclass/python-r1.eclass b/eclass/python-r1.eclass
index 713167d..0f73e3c 100644
--- a/eclass/python-r1.eclass
+++ b/eclass/python-r1.eclass
@@ -737,17 +737,56 @@ python_parallel_foreach_impl() {
}
# @FUNCTION: python_setup
+# @USAGE: [<impl-pattern>...]
# @DESCRIPTION:
-# Find the best (most preferred) Python implementation enabled
-# and set the Python build environment up for it.
+# Find the best (most preferred) Python implementation that is enabled
+# and matches at least one of the patterns passed (or '*' if no patterns
+# passed). Set the Python build environment up for that implementation.
#
# This function needs to be used when Python is being called outside
# of python_foreach_impl calls (e.g. for shared processes like doc
# building). python_foreach_impl sets up the build environment itself.
+#
+# If the specific commands support only a subset of Python
+# implementations, patterns need to be passed to restrict the allowed
+# implementations.
+#
+# Example:
+# @CODE
+# DEPEND="doc? ( dev-python/epydoc[$(python_gen_usedep 'python2*')] )"
+#
+# src_compile() {
+# #...
+# if use doc; then
+# python_setup 'python2*'
+# make doc
+# fi
+# }
+# @CODE
python_setup() {
debug-print-function ${FUNCNAME} "${@}"
- python_export_best
+ local best_impl patterns=( "${@-*}" )
+ _python_try_impl() {
+ local pattern
+ for pattern in "${patterns[@]}"; do
+ if [[ ${EPYTHON} == ${pattern} ]]; then
+ best_impl=${EPYTHON}
+ fi
+ done
+ }
+ python_foreach_impl _python_try_impl
+
+ if [[ ! ${best_impl} ]]; then
+ eerror "${FUNCNAME}: none of the enabled implementation matched
the patterns."
+ eerror " patterns: ${@-'(*)'}"
+ eerror "Likely a REQUIRED_USE constraint (possibly
USE-conditional) is missing."
+ eerror " suggested: || ( \$(python_gen_useflags ${@}) )"
+ eerror "(remember to quote all the patterns with '')"
+ die "${FUNCNAME}: no enabled implementation satisfy
requirements"
+ fi
+
+ python_export "${best_impl}" EPYTHON PYTHON
python_wrapper_setup
}
--
2.2.1
