waf: migrate to version.py

Fixes https://github.com/mpv-player/mpv-build/issues/204

version.py

@@ -6,15 +6,16 @@ import time
 
 from datetime import datetime,timezone
 from shutil import which
-from subprocess import check_output
+from subprocess import check_output, DEVNULL
 
 srcdir = os.path.dirname(os.path.abspath(sys.argv[0]))
 git_dir = os.path.join(srcdir, ".git")
 git = which('git')
 
 if git and os.path.exists(git_dir):
+    # stdin is set to DEVNULL to workaround waf preforking issues
     version = check_output([git, "-C", srcdir, "describe", "--always", "--tags",
-                            "--dirty"], encoding="UTF-8")
+                            "--dirty"], stdin=DEVNULL, encoding="UTF-8")
     version = version[1:].strip()
 else:
     version_path = os.path.join(srcdir, "VERSION")

version.sh

@@ -1,66 +0,0 @@
-#!/bin/sh
-
-export LC_ALL=C
-
-version_h="version.h"
-print=yes
-
-for ac_option do
-  ac_arg=$(echo $ac_option | cut -d '=' -f 2-)
-  case "$ac_option" in
-  --extra=*)
-    extra="-$ac_arg"
-    ;;
-  --versionh=*)
-    version_h="$(pwd)/$ac_arg"
-    print=no
-    ;;
-  --cwd=*)
-    cwd="$ac_arg"
-    ;;
-  *)
-    echo "Unknown parameter: $ac_option" >&2
-    exit 1
-    ;;
-
-  esac
-done
-
-if test "$cwd" ; then
-  cd "$cwd"
-fi
-
-# Extract revision number from file used by daily tarball snapshots
-# or from "git describe" output
-git_revision=$(cat snapshot_version 2> /dev/null)
-test "$git_revision" || test ! -e .git || git_revision="$(git describe \
-    --match "v[0-9]*" --always --tags --dirty | sed 's/^v//')"
-version="$git_revision"
-
-# other tarballs extract the version number from the VERSION file
-if test ! "$version"; then
-    version="$(cat VERSION 2> /dev/null)"
-fi
-
-test "$version" || version=UNKNOWN
-
-VERSION="${version}${extra}"
-
-if test "$print" = yes ; then
-    echo "$VERSION"
-    exit 0
-fi
-
-NEW_REVISION="#define VERSION \"${VERSION}\""
-OLD_REVISION=$(head -n 1 "$version_h" 2> /dev/null)
-BUILDDATE="#define BUILDDATE \"$(date)\""
-MPVCOPYRIGHT="#define MPVCOPYRIGHT \"Copyright © 2000-2023 mpv/MPlayer/mplayer2 projects\""
-
-# Update version.h only on revision changes to avoid spurious rebuilds
-if test "$NEW_REVISION" != "$OLD_REVISION"; then
-    cat <<EOF > "$version_h"
-$NEW_REVISION
-$BUILDDATE
-$MPVCOPYRIGHT
-EOF
-fi

wscript

@@ -1018,7 +1018,7 @@ def configure(ctx):
 
     ctx.add_os_flags('LIBRARY_PATH')
 
-    ctx.load('compiler_c')
+    ctx.load('compiler_c python')
     ctx.load('waf_customizations')
     ctx.load('dependencies')
     ctx.load('detections.compiler_swift')
@@ -1075,16 +1075,11 @@ def configure(ctx):
     Logs.error("WARNING: Building mpv with waf is deprecated and will be removed the future! It is recommended to switch to meson as soon as possible.")
 
 def __write_version__(ctx):
-    ctx.env.VERSIONH_ST = '--versionh="%s"'
-    ctx.env.CWD_ST = '--cwd="%s"'
-    ctx.env.VERSIONSH_CWD = [ctx.srcnode.abspath()]
-
     ctx(
-        source = 'version.sh',
+        source = 'version.py',
         target = 'generated/version.h',
-        rule   = 'sh ${SRC} ${CWD_ST:VERSIONSH_CWD} ${VERSIONH_ST:TGT}',
-        always = True,
-        update_outputs = True)
+        rule   = '${PYTHON} ${SRC} ${TGT}',
+        always = True)
 
 def build(ctx):
     if ctx.options.variant not in ctx.all_envs: