feat: Script for making the SDK self contained

scripts/make-self-contained.sh

@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+# Copyright 2026 Elektrobit. All rights reserved.
+#
+# Makes an SDK tree relocatable without patching any ELF headers.
+#
+# For every host executable shipped by the SDK (the same set of directories
+# `relocate-sdk.sh` / the ebclfsa `patch_cmds` operate on), this script:
+#   1. renames "$binary" to "$binary.real"
+#   2. drops a small shell wrapper at "$binary" that explicitly invokes the
+#      SDK's own loader (ld-linux) with an explicit --library-path, so the
+#      binary works no matter where the SDK tree is unpacked, without ever
+#      rewriting the ELF interpreter/rpath of "$binary.real".
+#
+# This is idempotent: binaries that are already wrappers (plain text, not
+# ELF) are skipped, so running the script twice on the same tree is a no-op
+# the second time.
+set -euo pipefail
+
+usage() {
+    echo "Usage: $0 <sdk-root>" >&2
+    exit 1
+}
+
+[ $# -eq 1 ] || usage
+
+sdk_root=$(cd "$1" && pwd)
+arch=$(uname -m)
+
+loader="$sdk_root/usr/lib/$arch-linux-gnu/ld-linux-x86-64.so.2"
+if [ ! -x "$loader" ]; then
+    echo "error: SDK loader not found at $loader" >&2
+    exit 1
+fi
+
+# Same search roots as relocate-sdk.sh / _EBCLFSA_RELOCATE_CMDS, filtered to
+# the ones that actually exist so an unmatched glob doesn't reach `find`.
+search_dirs=()
+for pattern in "$sdk_root"/usr/bin "$sdk_root"/usr/sbin \
+    "$sdk_root"/usr/lib/gcc* "$sdk_root"/usr/libexec/gcc* \
+    "$sdk_root"/usr/lib/llvm*/bin; do
+    [ -d "$pattern" ] && search_dirs+=("$pattern")
+done
+
+is_elf() {
+    local magic
+    magic=$(head -c4 "$1" 2>/dev/null | od -An -tx1 | tr -d ' \n')
+    [ "$magic" = "7f454c46" ]
+}
+
+count=0
+# Snapshot the file list up front: renaming files while `find` is still
+# walking the tree would let it re-discover freshly created "*.real" files
+# as if they were new binaries, and wrap them a second time.
+mapfile -d '' -t binaries < <(find "${search_dirs[@]}" -type f -perm -u+x -print0 2>/dev/null)
+for binary in "${binaries[@]}"; do
+    # A ".real" binary is the already-renamed original from a previous run;
+    # never re-wrap it (that would shadow it behind a second wrapper).
+    case "$binary" in
+    *.real) continue ;;
+    esac
+
+    # Shared libraries can be executable files too, but must remain ELF
+    # libraries because tools such as GCC load them directly as plugins.
+    case "$(basename "$binary")" in
+    *.so|*.so.*) continue ;;
+    esac
+    is_elf "$binary" || continue
+
+    dir=$(dirname "$binary")
+    name=$(basename "$binary")
+    real="$dir/$name.real"
+
+    [ -e "$real" ] && continue
+
+    # Relative path from the wrapper's own directory back to sdk_root, so the
+    # wrapper keeps working wherever the whole tree gets moved/extracted to.
+    rel_to_root=$(realpath --relative-to="$dir" "$sdk_root")
+
+    mv "$binary" "$real"
+    cat >"$binary" <<EOF
+#!/bin/sh
+here=\$(dirname "\$(readlink -f "\$0")")
+sdk=\$here/$rel_to_root
+exec "\$sdk/usr/lib/$arch-linux-gnu/ld-linux-x86-64.so.2" \\
+    --argv0 "\$0" \\
+    --library-path "\$sdk/usr/lib/$arch-linux-gnu:\$sdk/lib/$arch-linux-gnu" \\
+    "\$here/$name.real" "\$@"
+EOF
+    chmod +x "$binary"
+    count=$((count + 1))
+done
+
+echo "wrapped $count binaries under $sdk_root"