lang/python: add bytecode trigger

Facilitates compiling, writing and removing bytecode files (.pyc)
in site-packages after all pkg transactions have been completed.

Technical details: https://wiki.freebsd.org/Python/CompiledPackages

Fixes reports of Python port builds as root failing on filesystem
violations due to bytecode file writes where the port did not include
them in the package.

For those ports/packages that currently package bytecode, some
checksum mismatches on those files may occur. This is harmless and
will be rectified, in large as part of a USE_PYTHON=distutils
overhaul to reduce churn.

While here, implement a long-standing todo item of letting lang/python
ports use python.mk bits. Not only does this obviate duplicate
variables in each Makefile, but SUB_LIST (also added) is used for
these triggers.

Co-authored by: tcberner
Approved by: tcberner (mentor)
Differential Revision: https://reviews.freebsd.org/D34739

2 files changed, 44 insertions, 7 deletions

diff --git a/lang/python310/Makefile b/lang/python310/Makefile
index 7e51ea43cce1..66974f6c5366 100644
--- a/lang/python310/Makefile
+++ b/lang/python310/Makefile
@@ -1,5 +1,6 @@
 PORTNAME=	python
 DISTVERSION=	${PYTHON_DISTVERSION}
+PORTREVISION=	1
 CATEGORIES=	lang python
 MASTER_SITES=	PYTHON/ftp/python/${DISTVERSION:C/[a-z].*//}
 PKGNAMESUFFIX=	${PYTHON_SUFFIX}
@@ -14,8 +15,8 @@ LICENSE=	PSFL
 
 LIB_DEPENDS=	libffi.so:devel/libffi
 
-USES=		compiler:c11 cpe ncurses pathfix pkgconfig readline \
-		shebangfix ssl tar:xz
+USES=		compiler:c11 cpe ncurses pathfix pkgconfig \
+		python:${PYTHON_DISTVERSION:R},env readline shebangfix ssl tar:xz trigger
 PATHFIX_MAKEFILEIN=	Makefile.pre.in
 USE_LDCONFIG=	yes
 GNU_CONFIGURE=	yes
@@ -24,11 +25,7 @@ SHEBANG_FILES=	Lib/*.py Lib/*/*.py Lib/*/*/*.py Lib/*/*/*/*.py
 SHEBANG_FILES+=	Lib/test/ziptestdata/exe_with_z64 \
 		Lib/test/ziptestdata/exe_with_zip \
 		Lib/test/ziptestdata/header.sh
-
-# Duplicate python.mk variables. TODO: Let lang/python?? ports use python.mk bits.
-PYTHON_VER=		${PYTHON_DISTVERSION:R}
-PYTHON_VERSION=		python${PYTHON_VER}
-PYTHON_SUFFIX=		${PYTHON_VER:S/.//g}
+TRIGGERS=	${PYTHON_VERSION}
 
 DISABLED_EXTENSIONS=	_sqlite3 _tkinter _gdbm
 CONFIGURE_ARGS+=	--enable-shared --without-ensurepip \
diff --git a/lang/python310/files/python3.10.ucl.in b/lang/python310/files/python3.10.ucl.in
new file mode 100644
index 000000000000..63d455839549
--- /dev/null
+++ b/lang/python310/files/python3.10.ucl.in
@@ -0,0 +1,40 @@
+path_glob: "%%PYTHON_SITELIBDIR%%/*"
+trigger: {
+	type: lua
+	sandbox: false
+	script: <<EOS
+function cleanup(directory)
+  for _,d in ipairs(pkg.readdir(directory)) do
+    local full_path = directory .. "/" .. d
+    local stat = pkg.stat(full_path)
+    if stat["type"] == "dir" then
+      if (d ~= "__pycache__") then
+        cleanup(full_path)
+      else
+        for _,bytecode_file in ipairs(pkg.readdir(full_path)) do
+          local file_origin = string.gsub(bytecode_file, "[.]cpython[-]%%PYTHON_SUFFIX%%[.].*pyc", ".py")
+          if file_origin  then
+            local origin_path = directory .. "/" .. file_origin
+            if (not pkg.stat(origin_path)) then
+              --print("  >=> removed stale bytecode " .. bytecode_file)
+              os.remove(full_path .. "/" .. bytecode_file)
+            end
+          end
+        end
+      end
+      local res = pkg.readdir(full_path)
+      if #res == 0 then
+        --print("  >=> removed empty directory " .. full_path )
+        os.remove(full_path)
+      end
+    end
+  end
+end
+
+print(">=> Cleaning stale bytecode files...")
+cleanup("%%PYTHON_SITELIBDIR%%")
+
+print(">=> Byte-compiling Python source files...")
+pkg.exec({"%%PYTHON_VERSION%%", "-m", "compileall", "-q", "-o", "0", "-o", "1", "-o", "2", "%%PYTHON_SITELIBDIR%%"})
+EOS
+}