Add support for emitting code with a single return at the end. (#153)

This also enables testing of the wasmtests tests.

This also updates for wabt updating to the official "wat" filename
extension, as opposed to "wast".

cranelift/src/wasm.rs

@@ -1,5 +1,4 @@
-//! CLI tool to use the functions provided by crates [wasm2cretonne](../wasm2cretonne/index.html)
-//! and [wasmstandalone](../wasmstandalone/index.html).
+//! CLI tool to use the functions provided by the [cretonne-wasm](../cton_wasm/index.html) crate.
 //!
 //! Reads Wasm binary files (one Wasm module per file), translates the functions' code to Cretonne
 //! IL. Can also executes the `start` function of the module by laying out the memories, globals
@@ -13,6 +12,7 @@ use cretonne::dominator_tree::DominatorTree;
 use cretonne::Context;
 use cretonne::result::CtonError;
 use cretonne::verifier;
+use cretonne::settings::{self, Configurable};
 use std::fs::File;
 use std::error::Error;
 use std::io;
@@ -54,7 +54,16 @@ pub fn run(
     flag_verbose: bool,
     flag_optimize: bool,
     flag_check: bool,
+    flag_enable: Vec<String>,
 ) -> Result<(), String> {
+    let mut flag_builder = settings::builder();
+    for enable in flag_enable {
+        flag_builder.enable(&enable).map_err(|_| {
+            format!("unrecognized flag: {}", enable)
+        })?;
+    }
+    let flags = settings::Flags::new(&flag_builder);
+
     for filename in files {
         let path = Path::new(&filename);
         let name = String::from(path.as_os_str().to_string_lossy());
@@ -64,6 +73,7 @@ pub fn run(
             flag_check,
             path.to_path_buf(),
             name,
+            &flags,
         ) {
             Ok(()) => {}
             Err(message) => return Err(message),
@@ -78,6 +88,7 @@ fn handle_module(
     flag_check: bool,
     path: PathBuf,
     name: String,
+    flags: &settings::Flags,
 ) -> Result<(), String> {
     let mut terminal = term::stdout().unwrap();
     terminal.fg(term::color::YELLOW).unwrap();
@@ -89,7 +100,7 @@ fn handle_module(
     terminal.reset().unwrap();
     let data = match path.extension() {
         None => {
-            return Err(String::from("the file extension is not wasm or wast"));
+            return Err(String::from("the file extension is not wasm or wat"));
         }
         Some(ext) => {
             match ext.to_str() {
@@ -101,17 +112,17 @@ fn handle_module(
                         }
                     }
                 }
-                Some("wast") => {
-                    let tmp_dir = TempDir::new("wasm2cretonne").unwrap();
+                Some("wat") => {
+                    let tmp_dir = TempDir::new("cretonne-wasm").unwrap();
                     let file_path = tmp_dir.path().join("module.wasm");
                     File::create(file_path.clone()).unwrap();
-                    Command::new("wast2wasm")
+                    Command::new("wat2wasm")
                         .arg(path.clone())
                         .arg("-o")
                         .arg(file_path.to_str().unwrap())
                         .output()
                         .or_else(|e| if let io::ErrorKind::NotFound = e.kind() {
-                            return Err(String::from("wast2wasm not found"));
+                            return Err(String::from("wat2wasm not found"));
                         } else {
                             return Err(String::from(e.description()));
                         })
@@ -124,12 +135,12 @@ fn handle_module(
                     }
                 }
                 None | Some(&_) => {
-                    return Err(String::from("the file extension is not wasm or wast"));
+                    return Err(String::from("the file extension is not wasm or wat"));
                 }
             }
         }
     };
-    let mut dummy_runtime = DummyRuntime::new();
+    let mut dummy_runtime = DummyRuntime::with_flags(flags.clone());
     let translation = {
         let runtime: &mut WasmRuntime = &mut dummy_runtime;
         match translate_module(&data, runtime) {