Modernize C builds with offline dependencies and portable runtime helpers (#3050)

Bundle pinned offline dependencies, remove libcork/libipset and submodule requirements, and add portable runtime helpers with relocatable static/shared library installations.

Add Clang static build validation for Linux/musl, macOS and Windows, real TCP/UDP and SIP003 interoperability coverage, and recorded performance tradeoffs. All 21 hosted checks pass at the reviewed PR head 8d504e6218.

scripts/git_archive.sh

@@ -1,44 +1,14 @@
 #!/usr/bin/env bash
-set -e
-
-archive() {
-    export TARBALL_NAME=$1
-    export TARBALL_OUTDIR=$2
-
-    # archive this repo
-    cd "$(git rev-parse --show-toplevel)"
-    git archive HEAD --format=tar --prefix="${TARBALL_NAME}/" \
-        -o "${TARBALL_OUTDIR}/${TARBALL_NAME}.tar"
-    # archive submodules
-    git submodule update --init
-    git submodule foreach --quiet 'git archive HEAD --format=tar \
-            --prefix="${TARBALL_NAME}/${path}/" \
-            -o "${TARBALL_OUTDIR}/${TARBALL_NAME}-submodule-${path}-${sha1}.tar"
-        tar -n --concatenate --file="${TARBALL_OUTDIR}/${TARBALL_NAME}.tar" \
-            "${TARBALL_OUTDIR}/${TARBALL_NAME}-submodule-${path}-${sha1}.tar"'
-    gzip -c "${TARBALL_OUTDIR}/${TARBALL_NAME}.tar" > "${TARBALL_OUTDIR}/${TARBALL_NAME}.tar.gz"
-
-    # clean-up
-    git submodule foreach --quiet 'rm ${TARBALL_OUTDIR}/${TARBALL_NAME}-submodule-${path}-${sha1}.tar'
-    rm "${TARBALL_OUTDIR}/${TARBALL_NAME}.tar"
-}
-
-TARGET_TARBALL_NAME=shadowsocks-libev
-TARGET_TARBALL_DIR=$(git rev-parse --show-toplevel)
-
-while getopts "n:o:" opt
-do
-    case ${opt} in
-        o)
-            TARGET_TARBALL_DIR=$(readlink -f -- $OPTARG)
-            ;;
-        n)
-            TARGET_TARBALL_NAME=$OPTARG
-            ;;
-        \?)
-            exit 1
-            ;;
+# Backward-compatible maintainer entrypoint for the offline release archive.
+set -euo pipefail
+root=$(git rev-parse --show-toplevel)
+name=shadowsocks-libev
+directory=$root
+while getopts "n:o:" opt; do
+    case "$opt" in
+        n) name=$OPTARG ;;
+        o) directory=$OPTARG ;;
+        *) exit 1 ;;
     esac
 done
-
-archive "${TARGET_TARBALL_NAME}" "${TARGET_TARBALL_DIR}"
+exec python3 "$root/scripts/source_archive.py" "$directory/$name.tar.gz" --prefix "$name"