clif-util: Switch to using structopt for CLI arguments

cranelift/src/souper_to_peepmatic.rs

@@ -1,9 +1,22 @@
 use anyhow::{Context, Result};
 use std::io::{Read, Write};
-use std::path::Path;
+use std::path::{Path, PathBuf};
+use structopt::StructOpt;
 
-pub fn run(input: &Path, output: &Path) -> Result<()> {
-    let peepmatic_dsl = if input == Path::new("-") {
+/// Convert Souper optimizations into Peepmatic DSL.
+#[derive(StructOpt)]
+pub struct Options {
+    /// Specify an input file to be used. Use '-' for stdin.
+    #[structopt(parse(from_os_str))]
+    input: PathBuf,
+
+    /// Specify the output file to be used. Use '-' for stdout.
+    #[structopt(short("o"), long("output"), default_value("-"), parse(from_os_str))]
+    output: PathBuf,
+}
+
+pub fn run(options: &Options) -> Result<()> {
+    let peepmatic_dsl = if options.input == Path::new("-") {
         let stdin = std::io::stdin();
         let mut stdin = stdin.lock();
         let mut souper_dsl = vec![];
@@ -13,18 +26,18 @@ pub fn run(input: &Path, output: &Path) -> Result<()> {
         let souper_dsl = String::from_utf8(souper_dsl).context("stdin is not UTF-8: {}")?;
         peepmatic_souper::convert_str(&souper_dsl, Some(Path::new("stdin")))?
     } else {
-        peepmatic_souper::convert_file(input)?
+        peepmatic_souper::convert_file(&options.input)?
     };
 
-    if output == Path::new("-") {
+    if options.output == Path::new("-") {
         let stdout = std::io::stdout();
         let mut stdout = stdout.lock();
         stdout
             .write_all(peepmatic_dsl.as_bytes())
             .context("error writing to stdout")?;
     } else {
-        std::fs::write(output, peepmatic_dsl.as_bytes())
-            .with_context(|| format!("error writing to {}", output.display()))?;
+        std::fs::write(&options.output, peepmatic_dsl.as_bytes())
+            .with_context(|| format!("error writing to {}", options.output.display()))?;
     }
 
     Ok(())