WIP: Add wasmldr integration test(s)

* Remove internal/wasmldr's build.rs
* Move wasmldr test sources to tests/wasm/*.wat
* Build tests/wasm/*.wat to OUT_DIR/bin/*.wasm in build.rs
* Add tests/wasmldr_tests.rs, which tries to run .wasm test binaries

TODO: gotta fix how we pass the module into the keep, because the test
doesn't work but this works OK:

  cargo run -- exec 3< $(find target -name hello_wasi_snapshot1.wasm | tail -n1)

Signed-off-by: Will Woods <will@profian.com>

Cargo.toml

@@ -55,6 +55,7 @@ vdso = "0.1"
 
 [build-dependencies]
 cc = "1.0"
+wat = "1.0"
 walkdir = "2"
 protobuf-codegen-pure = "2.25"
 sallyport = { git = "https://github.com/enarx/sallyport", rev = "a567a22665c7e5ba88a8c4acd64ab43ee32b4681", features = [ "asm" ] }

build.rs

@@ -107,6 +107,19 @@ fn build_cc_tests(in_path: &Path, out_path: &Path) {
     }
 }
 
+use wat;
+
+fn build_wasm_tests(in_path: &Path, out_path: &Path) {
+    for wat in find_files_with_extensions(&["wat"], &in_path) {
+        let wasm = out_path
+            .join(wat.file_stem().unwrap())
+            .with_extension("wasm");
+        let bin = wat::parse_file(&wat).unwrap_or_else(|_| panic!("failed to compile {:?}", &wat));
+        std::fs::write(&wasm, &bin).unwrap_or_else(|_| panic!("failed to write {:?}", &wasm));
+        println!("cargo:rerun-if-changed={}", &wat.display());
+    }
+}
+
 // Build a binary named `bin_name` from the crate located at `in_dir`,
 // targeting `target_name`, then strip the resulting binary and place it
 // at `out_dir`/bin/`bin_name`.
@@ -235,6 +248,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     build_cc_tests(&Path::new(CRATE).join(TEST_BINS_IN), &out_dir_bin);
     build_rs_tests(&Path::new(CRATE).join(TEST_BINS_IN), &out_dir_bin);
+    build_wasm_tests(&Path::new(CRATE).join("tests/wasm"), &out_dir_bin);
 
     let target = "x86_64-unknown-linux-musl";
 

tests/wasmldr_tests.rs

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: Apache-2.0
+
+use std::fs::File;
+use std::path::Path;
+use std::process::{Command, Stdio};
+//use std::os::unix::process::CommandExt;
+use process_control::{ChildExt, Output, Timeout};
+use std::io;
+use std::os::unix::io::{FromRawFd, IntoRawFd, RawFd};
+use std::time::Duration;
+
+extern crate libc;
+use libc::c_int;
+
+mod common;
+use common::{CRATE, KEEP_BIN, OUT_DIR, TEST_BINS_OUT, TIMEOUT_SECS};
+
+use serial_test::serial;
+//use anyhow::Result;
+
+const MODULE_FD: RawFd = 3;
+
+// wrap a libc call to return io::Result
+fn cvt(rv: c_int) -> io::Result<c_int> {
+    if rv == -1 {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(rv)
+    }
+}
+
+fn open_module(path: &Path) -> io::Result<File> {
+    let mut file = File::open(path)?;
+    let fd = file.into_raw_fd();
+    unsafe { file = File::from_raw_fd(cvt(libc::dup2(fd, MODULE_FD))?) }
+    Ok(file)
+}
+
+fn run_test(wasm: &str) -> Output {
+    let path = Path::new(CRATE)
+        .join(OUT_DIR)
+        .join(TEST_BINS_OUT)
+        .join(wasm);
+    let _fd3 = open_module(&path).unwrap();
+    let child = Command::new(KEEP_BIN)
+        .arg("exec")
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .unwrap_or_else(|e| panic!("failed to run `{:?}`: {:#?}", wasm, e));
+    let output = child
+        .with_output_timeout(Duration::from_secs(TIMEOUT_SECS))
+        .terminating()
+        .wait()
+        .unwrap_or_else(|e| panic!("failed to run `{}`: {:#?}", wasm, e))
+        .unwrap_or_else(|| panic!("process `{}` timed out", wasm));
+
+    let _exit_status = output.status.code().unwrap_or_else(|| {
+        panic!(
+            "process `{}` terminated by signal {:?}",
+            wasm,
+            output.status.signal()
+        )
+    });
+
+    // TODO: compare output.stdout, output.stderr, etc.
+
+    output
+}
+
+#[test]
+#[serial]
+fn hello_wasi_snapshot1() {
+    let out = run_test("hello_wasi_snapshot1.wasm");
+    assert_eq!(out.stdout, &b"Hello, world!\n"[..]);
+}