Replace more miscellaenous read_wasm utilities with wat::parse_file. (#601)

crates/test-programs/Cargo.toml

@@ -22,3 +22,4 @@ pretty_env_logger = "0.3.0"
 tempfile = "3.1.0"
 os_pipe = "0.9"
 anyhow = "1.0.19"
+wat = "1.0.2"

crates/test-programs/build.rs

@@ -127,7 +127,7 @@ fn write_testsuite_tests(out: &mut File, dir_entry: DirEntry, testsuite: &str) -
         "        let path = std::path::Path::new(r#\"{}\"#);",
         path.display()
     )?;
-    writeln!(out, "        let data = utils::read_wasm(path)?;")?;
+    writeln!(out, "        let data = wat::parse_file(path)?;")?;
     writeln!(
         out,
         "        let bin_name = utils::extract_exec_name_from_path(path)?;"

crates/test-programs/tests/wasm_tests/utils.rs

@@ -1,16 +1,6 @@
-use std::fs;
 use std::path::Path;
 use tempfile::{Builder, TempDir};
 
-pub fn read_wasm(path: &Path) -> anyhow::Result<Vec<u8>> {
-    let data = fs::read(path)?;
-    if data.starts_with(&[b'\0', b'a', b's', b'm']) {
-        Ok(data)
-    } else {
-        anyhow::bail!("Invalid Wasm file encountered")
-    }
-}
-
 pub fn prepare_workspace(exe_name: &str) -> anyhow::Result<TempDir> {
     let prefix = format!("wasi_common_{}", exe_name);
     let tempdir = Builder::new().prefix(&prefix).tempdir()?;

src/bin/wasm2obj.rs

@@ -38,11 +38,9 @@ use faerie::Artifact;
 use serde::Deserialize;
 use std::error::Error;
 use std::fmt::format;
-use std::fs::File;
-use std::io::prelude::*;
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
-use std::{io, process, str};
+use std::{process, str};
 use target_lexicon::Triple;
 use wasmtime_cli::pick_compilation_strategy;
 use wasmtime_debug::{emit_debugsections, read_debuginfo};
@@ -104,13 +102,6 @@ struct Args {
     flag_optimize: bool,
 }
 
-fn read_wasm_file(path: PathBuf) -> Result<Vec<u8>, io::Error> {
-    let mut buf: Vec<u8> = Vec::new();
-    let mut file = File::open(path)?;
-    file.read_to_end(&mut buf)?;
-    Ok(buf)
-}
-
 fn main() {
     let version = env!("CARGO_PKG_VERSION");
     let args: Args = Docopt::new(USAGE)
@@ -189,7 +180,7 @@ fn handle_module(
     cranelift: bool,
     lightbeam: bool,
 ) -> Result<(), String> {
-    let data = match read_wasm_file(path) {
+    let data = match wat::parse_file(path) {
         Ok(data) => data,
         Err(err) => {
             return Err(String::from(err.description()));