distutils-r1.eclass: Depend on setuptools by default

Add a new DISTUTILS_USE_SETUPTOOLS top variable, and make it default
to BDEPEND-ing on dev-python/setuptools (which should be correct
for the majority of packages).  Packages that either need RDEPEND
or no dependency at all can override it.

Also add a check for correct value in esetup.py.  This should make it
easy for developers to adjust the new variable in their packages.

Signed-off-by: Michał Górny <[email protected]>

eclass/distutils-r1.eclass

@@ -77,9 +77,23 @@ esac
 # to be exported. It must be run in order for the eclass functions
 # to function properly.
 
+# @ECLASS-VARIABLE: DISTUTILS_USE_SETUPTOOLS
+# @PRE_INHERIT
+# @DESCRIPTION:
+# Controls adding dev-python/setuptools dependency. The allowed values
+# are:
+#
+# - no -- do not add the dependency (pure distutils package)
+# - bdepend -- add it to BDEPEND (the default)
+# - rdepend -- add it to BDEPEND+RDEPEND (when using entry_points)
+#
+# This variable is effective only if DISTUTILS_OPTIONAL is disabled.
+# It needs to be set before the inherit line.
+: ${DISTUTILS_USE_SETUPTOOLS:=bdepend}
+
 if [[ ! ${_DISTUTILS_R1} ]]; then
 
-[[ ${EAPI} == [45] ]] && inherit eutils
+[[ ${EAPI} == [456] ]] && inherit eutils
 [[ ${EAPI} == [56] ]] && inherit xdg-utils
 inherit multiprocessing toolchain-funcs
 
@@ -97,15 +111,35 @@ fi
 
 if [[ ! ${_DISTUTILS_R1} ]]; then
 
-if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
- RDEPEND=${PYTHON_DEPS}
+_distutils_set_globals() {
+ local rdep=${PYTHON_DEPS}
+ local bdep=${rdep}
+
+ case ${DISTUTILS_USE_SETUPTOOLS} in
+ no)
+ ;;
+ bdepend)
+ bdep+=" dev-python/setuptools[${PYTHON_USEDEP}]"
+ ;;
+ rdepend)
+ bdep+=" dev-python/setuptools[${PYTHON_USEDEP}]"
+ rdep+=" dev-python/setuptools[${PYTHON_USEDEP}]"
+ ;;
+ *)
+ die "Invalid DISTUTILS_USE_SETUPTOOLS=${DISTUTILS_USE_SETUPTOOLS}"
+ ;;
+ esac
+
+ RDEPEND=${rdep}
  if [[ ${EAPI} != [56] ]]; then
- BDEPEND=${PYTHON_DEPS}
+ BDEPEND=${bdep}
  else
- DEPEND=${PYTHON_DEPS}
+ DEPEND=${bdep}
  fi
  REQUIRED_USE=${PYTHON_REQUIRED_USE}
-fi
+}
+[[ ! ${DISTUTILS_OPTIONAL} ]] && _distutils_set_globals
+unset -f _distutils_set_globals
 
 # @ECLASS-VARIABLE: PATCHES
 # @DEFAULT_UNSET
@@ -395,6 +429,41 @@ distutils_enable_tests() {
  return 0
 }
 
+# @FUNCTION: _distutils-r1_verify_use_setuptools
+# @INTERNAL
+# @DESCRIPTION:
+# Check setup.py for signs that DISTUTILS_USE_SETUPTOOLS have been set
+# incorrectly.
+_distutils_verify_use_setuptools() {
+ [[ ${DISTUTILS_OPTIONAL} ]] && return
+
+ # ok, those are cheap greps. we can try toimprove them if we hit
+ # false positives.
+ local expected=no
+ if [[ ${CATEGORY}/${PN} == dev-python/setuptools ]]; then
+ # as a special case, setuptools provides itself ;-)
+ :
+ elif grep -E -q -s '(from|import)\s+setuptools' setup.py; then
+ if grep -E -q -s 'entry_points\s+=' setup.py; then
+ expected=rdepend
+ else
+ expected=bdepend
+ fi
+ fi
+
+ if [[ ${DISTUTILS_USE_SETUPTOOLS} != ${expected} ]]; then
+ if [[ ! ${_DISTUTILS_SETUPTOOLS_WARNED} ]]; then
+ _DISTUTILS_SETUPTOOLS_WARNED=1
+ local def=
+ [[ ${DISTUTILS_USE_SETUPTOOLS} == bdepend ]] && def=' (default?)'
+
+ eqawarn "DISTUTILS_USE_SETUPTOOLS value is probably incorrect"
+ eqawarn " value: DISTUTILS_USE_SETUPTOOLS=${DISTUTILS_USE_SETUPTOOLS}${def}"
+ eqawarn " expected: DISTUTILS_USE_SETUPTOOLS=${expected}"
+ fi
+ fi
+}
+
 # @FUNCTION: esetup.py
 # @USAGE: [<args>...]
 # @DESCRIPTION:
@@ -417,6 +486,7 @@ esetup.py() {
  [[ ${EAPI} != [45] ]] && die_args+=( -n )
 
  [[ ${BUILD_DIR} ]] && _distutils-r1_create_setup_cfg
+ _distutils_verify_use_setuptools
 
  set -- "${EPYTHON:-python}" setup.py "${mydistutilsargs[@]}" "${@}"