scripts: Introduce seccompiler.py

`seccompiler.py` contains functions used to extract `syscall_table` from
headers installed by `kernel_source.py` and generate according Rust code
for specific architecture.

Signed-off-by: Ruoqing He <[email protected]>

Author: RuoqingHe

scripts/lib/seccompiler.py

@@ -0,0 +1,80 @@
+# Copyright 2025 © Institute of Software, CAS. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import subprocess
+import os
+import re
+from lib.kernel_source import prepare_source
+from lib import MAP_RUST_ARCH, SUPPORT_ARCHS
+from pathlib import Path
+
+SECCOMPILER_SYSCALL_DIR = "src/syscall_table"
+
+
+def generate_seccompiler(args):
+    installed_header_path = prepare_source(args)
+
+    # If arch is not provided, install headers for all supported archs
+    if args.arch is None:
+        for arch in SUPPORT_ARCHS:
+            generate_rust_code(installed_header_path, arch, args.output_path)
+    else:
+        generate_rust_code(installed_header_path, args.arch, args.output_path)
+
+
+def generate_rust_code(installed_header_path: str, arch: str, output_path: str):
+    # Generate syscall table
+    arch_headers = os.path.join(installed_header_path, f"{arch}_headers")
+    syscall_header = Path(os.path.join(arch_headers, f"include/asm/unistd_64.h"))
+    if not syscall_header.is_file():
+        raise FileNotFoundError(f"syscall headers missing at {syscall_header}")
+    syscalls = generate_syscall_table(syscall_header)
+
+    arch = MAP_RUST_ARCH[arch]
+    output_file_path = f"{output_path}/{arch}.rs"
+
+    """Generate Rust code and format with rustfmt"""
+    print(f"Generating to: {output_file_path}")
+    code = f"""use std::collections::HashMap;
+pub(crate) fn make_syscall_table() -> HashMap<&'static str, i64> {{
+    vec![
+        {syscalls}
+    ].into_iter().collect()
+}}
+"""
+    try:
+        with open(output_file_path, "w") as f:
+            f.write(code)
+
+        # Format with rustfmt
+        subprocess.run(["rustfmt", output_file_path], check=True)
+        print(f"Generation succeeded: {output_file_path}")
+    except subprocess.CalledProcessError:
+        raise RuntimeError("rustfmt formatting failed")
+    except IOError as e:
+        raise RuntimeError(f"File write error: {str(e)}")
+
+
+def generate_syscall_table(syscall_header_path: str):
+    """Generate syscall table from specified header file"""
+    try:
+        with open(syscall_header_path, "r") as f:
+            syscalls = []
+            pattern = re.compile(r"^#define __NR_(\w+)\s+(\d+)")
+
+            for line in f:
+                line = line.strip()
+                if line.startswith("#define __NR_"):
+                    match = pattern.match(line)
+                    if match:
+                        name = match.group(1)
+                        num = int(match.group(2))
+                        syscalls.append((name, num))
+
+            # Sort alphabetically by syscall name
+            syscalls.sort(key=lambda x: x[0])
+            syscall_list = [f'("{name}", {num}),' for name, num in syscalls]
+            return " ".join(syscall_list)
+
+    except Exception as e:
+        raise RuntimeError(f"File processing failed: {str(e)}")