Use Rust stubs instead of C (#28)

* Use Rust stubs instead of C

Signed-off-by: Jorge Prendes <jorge.prendes@gmail.com>

* Address PR comments

Signed-off-by: Jorge Prendes <jorge.prendes@gmail.com>

---------

Signed-off-by: Jorge Prendes <jorge.prendes@gmail.com>

Author: jprendes

Cargo.lock

@@ -11,14 +11,14 @@ PWD := replace(justfile_dir(), "\\", "/")
 # * include the stubs required by hyperlight-js-runtime
 # * define __wasi__ as this disables threading support in quickjs
 export HYPERLIGHT_CFLAGS := \
-    "-I" + PWD + "/src/hyperlight-js-runtime/stubs/include " + \
+    "-I" + PWD + "/src/hyperlight-js-runtime/include " + \
     "-D__wasi__=1 "
 
 # On Windows, use Ninja generator for CMake to avoid aws-lc-sys build issues with Visual Studio generator
 export CMAKE_GENERATOR := if os() == "windows" { "Ninja" } else { "" }
 
 ensure-tools:
-    cargo install cargo-hyperlight --locked --version 0.1.3
+    cargo install cargo-hyperlight --locked
 
 # Check if npm is installed, install automatically if missing (Linux)
 [private]
@@ -39,8 +39,7 @@ check-license-headers:
     ./dev/check-license-headers.sh
 
 clippy target=default-target features="": (ensure-tools)
-    cd src/hyperlight-js-runtime && \
-        cargo hyperlight clippy \
+    cargo hyperlight clippy -p hyperlight-js-runtime \
             --profile={{ if target == "debug" {"dev"} else { target } }} \
             -- -D warnings
     cargo clippy --all-targets \

Justfile

@@ -33,17 +33,17 @@ tracing = { version = "0.1.44", default-features = false, features = ["log","att
 hyperlight-common = { workspace = true, default-features = false }
 hyperlight-guest = { workspace = true }
 hyperlight-guest-bin = { workspace = true }
+chrono = { version = "0.4", default-features = false }
 
 [target.'cfg(not(hyperlight))'.dependencies]
 clap = { version = "4.5", features = ["derive"] }
-libc = "0.2"
 
 [target.'cfg(not(hyperlight))'.dev-dependencies]
 escargot = "0.5"
 tempfile = "3.26"
 
 [build-dependencies]
-cc = "1.2"
+bindgen = "0.72"
 
 [features]
 default = []

src/hyperlight-js-runtime/Cargo.toml

@@ -13,16 +13,38 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-fn main() {
-    if std::env::var_os("CARGO_CFG_HYPERLIGHT").is_none() {
-        return;
-    }
 
-    let files = ["stubs/clock.c", "stubs/localtime.c"];
+use std::env;
+use std::path::PathBuf;
 
-    for file in files {
-        println!("cargo:rerun-if-changed={}", file);
-    }
+use bindgen::RustEdition::Edition2024;
 
-    cc::Build::new().files(files).compile("stubs");
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut bindings = bindgen::builder()
+        .use_core()
+        .wrap_unsafe_ops(true)
+        .rust_edition(Edition2024)
+        .clang_arg("-D_POSIX_MONOTONIC_CLOCK=1")
+        .clang_arg("-D_POSIX_C_SOURCE=200809L");
+
+    bindings = bindings.header_contents(
+        "libc.h",
+        "
+        #pragma once
+        #include <errno.h>
+        #include <stdio.h>
+        #include <time.h>
+        ",
+    );
+
+    println!("cargo:rerun-if-changed=include");
+    println!("cargo:rerun-if-changed=include/stdio.h");
+    println!("cargo:rerun-if-changed=include/time.h");
+    println!("cargo:rerun-if-changed=include/unistd.h");
+
+    // Write the generated bindings to an output file.
+    let out_path = PathBuf::from(env::var("OUT_DIR")?).join("libc.rs");
+    bindings.generate()?.write_to_file(out_path)?;
+
+    Ok(())
 }

src/hyperlight-js-runtime/build.rs

@@ -0,0 +1,29 @@
+/*
+Copyright 2026 The Hyperlight Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+#pragma once
+
+#include "printf.h"
+#include_next "stdio.h"
+
+#define stdout NULL
+
+int putchar(int c);
+
+#define vfprintf(f, ...) vprintf(__VA_ARGS__)
+#define fprintf(f, ...) printf(__VA_ARGS__)
+#define fputc(c, f) putc((char)(c), f)
+
+int fflush(FILE *f);

src/hyperlight-js-runtime/include/stdio.h

@@ -0,0 +1,28 @@
+/*
+Copyright 2026 The Hyperlight Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+#pragma once
+
+#include_next "time.h"
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <errno.h>
+
+#define CLOCK_REALTIME 0
+#define CLOCK_MONOTONIC 1
+
+int clock_gettime(clockid_t clk_id, struct timespec *tp);
+struct tm *localtime_r(const time_t *timer, struct tm *tm);

src/hyperlight-js-runtime/include/time.h

@@ -0,0 +1,15 @@
+/*
+Copyright 2026 The Hyperlight Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/

src/hyperlight-js-runtime/include/unistd.h

@@ -20,6 +20,7 @@ extern crate alloc;
 mod globals;
 pub mod host;
 mod host_fn;
+mod libc;
 mod modules;
 pub(crate) mod utils;
 

src/hyperlight-js-runtime/src/lib.rs

@@ -0,0 +1,31 @@
+/*
+Copyright 2026 The Hyperlight Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+mod bindings {
+    #![allow(
+        non_camel_case_types,
+        non_snake_case,
+        non_upper_case_globals,
+        dead_code,
+        unnecessary_transmutes,
+        clippy::upper_case_acronyms,
+        clippy::ptr_offset_with_cast
+    )]
+    include!(concat!(env!("OUT_DIR"), "/libc.rs"));
+}
+
+pub(crate) use core::ffi::*;
+
+pub(crate) use bindings::*;

src/hyperlight-js-runtime/src/libc.rs

@@ -16,6 +16,9 @@ limitations under the License.
 #![cfg_attr(hyperlight, no_std)]
 #![cfg_attr(hyperlight, no_main)]
 
+#[cfg(hyperlight)]
+mod libc;
+
 #[cfg(hyperlight)]
 include!("main/hyperlight.rs");