Add auto-generation script for syscall mappings

scripts/generate_syscall_mappings.py

@@ -0,0 +1,134 @@
+#!/usr/bin/env python3
+# Auto-generates syscall mapping constants for lind-wasm.
+#
+# Reads syscall definitions from glibc's lind_syscall_num.h and generates:
+#  - src/sysdefs/src/constants/syscall_const.rs (full set)
+#  - src/wasmtime/crates/lind-utils/src/lind_syscall_numbers.rs (minimal set)
+#
+# Source of truth: src/glibc/lind_syscall/lind_syscall_num.h
+
+from __future__ import annotations
+
+import re
+import sys
+from pathlib import Path
+
+
+def parse_c_header(header_path: str) -> dict[str, int]:
+    """Parse syscall constants from glibc's lind_syscall_num.h header file."""
+    syscalls = {}
+
+    try:
+        with open(header_path) as f:
+            content = f.read()
+    except FileNotFoundError:
+        print(f"Error: Could not find {header_path}", file=sys.stderr)
+        sys.exit(1)
+
+    # Match #define SYSCALL_NAME number
+    pattern = r'#define\s+(\w+)\s+(\d+)'
+
+    for match in re.finditer(pattern, content):
+        name, number = match.groups()
+        syscalls[name] = int(number)
+
+    if not syscalls:
+        print(f"Error: Could not parse any syscalls from {header_path}", file=sys.stderr)
+        sys.exit(1)
+
+    return syscalls
+
+
+def generate_rust_constants(syscalls: dict[str, int]) -> str:
+    """Generate Rust constants for sysdefs/constants/syscall_const.rs."""
+    lines = [
+        "//! Syscall number constants for the Lind platform.",
+        "//!",
+        "//! Source of truth: Linux x86_64 syscall table",
+        "//!   https://github.com/torvalds/linux/blob/v6.16-rc1/arch/x86/entry/syscalls/syscall_64.tbl",
+        "//! (Historical overview: https://filippo.io/linux-syscall-table/)",
+        "//!",
+        "//! Keep these in sync with glibc's lind_syscall_num.h and RawPOSIX dispatcher.",
+        "",
+    ]
+
+    # Sort by syscall number for readability
+    sorted_syscalls = sorted(syscalls.items(), key=lambda x: x[1])
+
+    for name, number in sorted_syscalls:
+        lines.append(f"pub const {name}: i32 = {number};")
+
+    lines.append("")
+    return "\n".join(lines)
+
+
+def get_minimal_syscalls() -> dict[str, int]:
+    """Return the minimal set of syscalls needed by Wasmtime runtime."""
+    return {
+        'MMAP_SYSCALL': 9,
+        'CLONE_SYSCALL': 56,
+        'FORK_SYSCALL': 57,
+        'EXEC_SYSCALL': 59,
+        'EXIT_SYSCALL': 60,
+        'EXIT_GROUP_SYSCALL': 231,
+    }
+
+
+def generate_wasmtime_minimal(minimal: dict[str, int]) -> str:
+    """Generate minimal Rust constants for wasmtime lind_syscall_numbers.rs."""
+    lines = [
+        "// Minimal set of syscall numbers used by Wasmtime side for Lind",
+        "// Keeps the runtime minimal and the rawposix dispatcher handles the rest",
+        "// Source of truth: Linux x86_64 syscall table",
+        "//   https://github.com/torvalds/linux/blob/v6.16-rc1/arch/x86/entry/syscalls/syscall_64.tbl",
+        "// (Historical overview: https://filippo.io/linux-syscall-table/)",
+        "// Keep these in sync with glibc's lind_syscall_num.h and RawPOSIX dispatcher",
+    ]
+
+    # Sort by syscall number
+    sorted_syscalls = sorted(minimal.items(), key=lambda x: x[1])
+
+    for name, number in sorted_syscalls:
+        lines.append(f"pub const {name}: i32 = {number};")
+
+    lines.append("")
+    return "\n".join(lines)
+
+
+def write_file(path: str, content: str) -> None:
+    """Write content to file, creating directories if needed."""
+    Path(path).parent.mkdir(parents=True, exist_ok=True)
+    with open(path, 'w') as f:
+        f.write(content)
+    print(f"Generated: {path}")
+
+
+def main() -> None:
+    """Generate all syscall mapping files."""
+    # Find workspace root (should be run from lind-wasm directory)
+    workspace_root = Path(__file__).parent.parent
+
+    c_header = workspace_root / "src/glibc/lind_syscall/lind_syscall_num.h"
+    rust_sysdefs_out = workspace_root / "src/sysdefs/src/constants/syscall_const.rs"
+    rust_wasmtime_out = workspace_root / "src/wasmtime/crates/lind-utils/src/lind_syscall_numbers.rs"
+
+    print("Parsing syscall definitions...")
+    syscalls = parse_c_header(str(c_header))
+    print(f"Found {len(syscalls)} syscall definitions")
+
+    # Generate full Rust constants for sysdefs
+    print("\nGenerating sysdefs constants...")
+    rust_content = generate_rust_constants(syscalls)
+    write_file(str(rust_sysdefs_out), rust_content)
+
+    # Generate minimal constants for wasmtime
+    print("Generating wasmtime minimal constants...")
+    minimal = get_minimal_syscalls()
+    wasmtime_content = generate_wasmtime_minimal(minimal)
+    write_file(str(rust_wasmtime_out), wasmtime_content)
+
+    print("\nDone!")
+
+
+if __name__ == "__main__":
+    main()