python-utils-r1.eclass: Support matching impls by stdlib version

Update _python_impl_matches() (used to implement python_gen*,
python_setup) to support specifying stdlib versions ("3.8", "3.9")
in addition to exact implementation names.  This makes handling PyPy3
version changes much easier when dealing with backports.

For example, if you specify "3.8", then the spec will match python3_8
and pypy3, for as long as we supply PyPy3.8.  Once we upgrade to PyPy3.9
completely, it will stop matching pypy3 and we won't have to manually
keep updating these deps.

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

4 files changed, 36 insertions, 44 deletions

diff --git a/eclass/distutils-r1.eclass b/eclass/distutils-r1.eclass
index a1b840d9cc68..fd3dffeac31c 100644
--- a/eclass/distutils-r1.eclass
+++ b/eclass/distutils-r1.eclass
@@ -333,9 +333,8 @@ unset -f _distutils_set_globals
 # (allowing any implementation). If multiple values are specified,
 # implementations matching any of the patterns will be accepted.
 #
-# The patterns are fnmatch-style patterns (matched via bash == operator
-# against PYTHON_COMPAT values). Remember to escape or quote the fnmatch
-# patterns to prevent accidental shell filename expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # If the restriction needs to apply conditionally to a USE flag,
 # the variable should be set conditionally as well (e.g. in an early
diff --git a/eclass/python-r1.eclass b/eclass/python-r1.eclass
index bb851e167617..bf2fd62fdcba 100644
--- a/eclass/python-r1.eclass
+++ b/eclass/python-r1.eclass
@@ -289,11 +289,6 @@ _python_validate_useflags() {
 # are both in PYTHON_COMPAT and match any of the patterns passed
 # as parameters to the function.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
-#
 # This is an internal function used to implement python_gen_cond_dep.
 _python_gen_usedep() {
 	debug-print-function ${FUNCNAME} "${@}"
@@ -322,10 +317,8 @@ _python_gen_usedep() {
 # are both in PYTHON_COMPAT and match any of the patterns passed
 # as parameters to the function.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # Example:
 # @CODE
@@ -359,10 +352,8 @@ python_gen_useflags() {
 # of Python implementations which are both in PYTHON_COMPAT and match
 # any of the patterns passed as the remaining parameters.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # In order to enforce USE constraints on the packages, verbatim
 # '${PYTHON_USEDEP}' (quoted!) may be placed in the dependency
@@ -423,10 +414,8 @@ python_gen_cond_dep() {
 # patterns are passed, the output dependencies will be generated only
 # for the implementations matching them.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # Use this function when you need to request different USE flags
 # on the Python interpreter depending on package's USE flags. If you
@@ -479,10 +468,8 @@ python_gen_impl_dep() {
 #
 # Optionally, patterns may be specified to restrict the dependency to
 # a subset of Python implementations supported by the ebuild.
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # This should be used along with an appropriate python_check_deps()
 # that checks which of the any-of blocks were matched, and python_setup
@@ -669,10 +656,8 @@ python_foreach_impl() {
 # The python_check_deps() function in the any-of mode needs to be
 # accompanied by appropriate any-of dependencies.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # This function needs to be used when Python is being called outside
 # of python_foreach_impl calls (e.g. for shared processes like doc
diff --git a/eclass/python-single-r1.eclass b/eclass/python-single-r1.eclass
index 0e9a16a47d0e..998e6faad841 100644
--- a/eclass/python-single-r1.eclass
+++ b/eclass/python-single-r1.eclass
@@ -266,10 +266,8 @@ if [[ ! ${_PYTHON_SINGLE_R1} ]]; then
 # are both in PYTHON_COMPAT and match any of the patterns passed
 # as parameters to the function.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # Example:
 # @CODE
@@ -303,10 +301,8 @@ python_gen_useflags() {
 # of Python implementations which are both in PYTHON_COMPAT and match
 # any of the patterns passed as the remaining parameters.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # In order to enforce USE constraints on the packages, verbatim
 # '${PYTHON_SINGLE_USEDEP}' and '${PYTHON_USEDEP}' (quoted!) may
@@ -359,10 +355,8 @@ python_gen_cond_dep() {
 # patterns are passed, the output dependencies will be generated only
 # for the implementations matching them.
 #
-# The patterns are fnmatch-style patterns (matched via bash
-# == operator against PYTHON_COMPAT values).  Remember to escape
-# or quote the fnmatch patterns to prevent accidental shell filename
-# expansion.
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
 #
 # Use this function when you need to request different USE flags
 # on the Python interpreter depending on package's USE flags. If you
diff --git a/eclass/python-utils-r1.eclass b/eclass/python-utils-r1.eclass
index 9dc23bf9bfb0..0703d81d9161 100644
--- a/eclass/python-utils-r1.eclass
+++ b/eclass/python-utils-r1.eclass
@@ -82,7 +82,11 @@ _python_verify_patterns() {
 
 	local impl pattern
 	for pattern; do
-		[[ ${pattern} == -[23] ]] && continue
+		case ${pattern} in
+			-[23]|3.[89]|3.10)
+				continue
+				;;
+		esac
 
 		for impl in "${_PYTHON_ALL_IMPLS[@]}" "${_PYTHON_HISTORICAL_IMPLS[@]}"
 		do
@@ -190,12 +194,14 @@ _python_set_impls() {
 # Matches if no patterns are provided.
 #
 # <impl> can be in PYTHON_COMPAT or EPYTHON form. The patterns
-# are fnmatch-style.
+# can either be fnmatch-style or stdlib versions, e.g. "3.8", "3.9".
+# In the latter case, pypy3 will match if there is at least one pypy3
+# version matching the stdlib version.
 _python_impl_matches() {
 	[[ ${#} -ge 1 ]] || die "${FUNCNAME}: takes at least 1 parameter"
 	[[ ${#} -eq 1 ]] && return 0
 
-	local impl=${1} pattern
+	local impl=${1/./_} pattern
 	shift
 
 	for pattern; do
@@ -218,9 +224,17 @@ _python_impl_matches() {
 				fi
 				return 0
 				;;
+			3.8)
+				# the only unmasked pypy3 version is pypy3.8 atm
+				[[ ${impl} == python${pattern/./_} || ${impl} == pypy3 ]] &&
+					return 0
+				;;
+			3.9|3.10)
+				[[ ${impl} == python${pattern/./_} ]] && return 0
+				;;
 			*)
 				# unify value style to allow lax matching
-				[[ ${impl/./_} == ${pattern/./_} ]] && return 0
+				[[ ${impl} == ${pattern/./_} ]] && return 0
 				;;
 		esac
 	done