roc run passes through arguments and exit code

cli/src/build.rs

@@ -7,7 +7,6 @@ use roc_can::builtins::builtin_defs_map;
 use roc_collections::all::MutMap;
 use roc_gen::llvm::build::OptLevel;
 use roc_load::file::LoadingProblem;
-use std::env;
 use std::path::PathBuf;
 use std::time::{Duration, SystemTime};
 use target_lexicon::Triple;
@@ -21,6 +20,18 @@ fn report_timing(buf: &mut String, label: &str, duration: Duration) {
     ));
 }
 
+pub enum BuildOutcome {
+    NoProblems,
+    OnlyWarnings,
+    Errors,
+}
+
+pub struct BuiltFile {
+    pub binary_path: PathBuf,
+    pub outcome: BuildOutcome,
+    pub total_time: Duration,
+}
+
 pub fn build_file<'a>(
     arena: &'a Bump,
     target: &Triple,
@@ -29,7 +40,7 @@ pub fn build_file<'a>(
     opt_level: OptLevel,
     emit_debug_info: bool,
     link_type: LinkType,
-) -> Result<PathBuf, LoadingProblem<'a>> {
+) -> Result<BuiltFile, LoadingProblem<'a>> {
     let compilation_start = SystemTime::now();
     let ptr_bytes = target.pointer_width().unwrap().bytes() as u32;
 
@@ -184,26 +195,23 @@ pub fn build_file<'a>(
         todo!("gracefully handle error after `rustc` spawned");
     });
 
-    let link_end = link_start.elapsed().unwrap();
+    let linking_time = link_start.elapsed().unwrap();
+
     if emit_debug_info {
-        println!("Finished linking in {} ms\n", link_end.as_millis());
+        println!("Finished linking in {} ms\n", linking_time.as_millis());
     }
 
+    let total_time = compilation_start.elapsed().unwrap();
+
     // If the cmd errored out, return the Err.
     cmd_result?;
 
-    // If possible, report the generated executable name relative to the current dir.
-    let generated_filename = binary_path
-        .strip_prefix(env::current_dir().unwrap())
-        .unwrap_or(&binary_path);
+    // TODO change this to report whether there were errors or warnings!
+    let outcome = BuildOutcome::NoProblems;
 
-    let total_end = compilation_start.elapsed().unwrap();
-
-    println!(
-        "🎉 Built {} in {} ms",
-        generated_filename.to_str().unwrap(),
-        total_end.as_millis()
-    );
-
-    Ok(binary_path)
+    Ok(BuiltFile {
+        binary_path,
+        total_time,
+        outcome,
+    })
 }

cli/src/lib.rs

@@ -1,12 +1,13 @@
 #[macro_use]
 extern crate clap;
 
+use build::{build_file, BuildOutcome, BuiltFile};
 use bumpalo::Bump;
-use clap::ArgMatches;
-use clap::{App, Arg};
+use clap::{App, AppSettings, Arg, ArgMatches};
 use roc_build::link::LinkType;
 use roc_gen::llvm::build::OptLevel;
 use roc_load::file::LoadingProblem;
+use std::env;
 use std::io;
 use std::path::{Path, PathBuf};
 use std::process;
@@ -16,18 +17,25 @@ use target_lexicon::Triple;
 pub mod build;
 pub mod repl;
 
-pub static FLAG_DEBUG: &str = "debug";
-pub static FLAG_OPTIMIZE: &str = "optimize";
-pub static FLAG_ROC_FILE: &str = "ROC_FILE";
-pub static DIRECTORY_OR_FILES: &str = "DIRECTORY_OR_FILES";
+pub const CMD_RUN: &str = "run";
+pub const CMD_BUILD: &str = "build";
+pub const CMD_REPL: &str = "repl";
+pub const CMD_EDIT: &str = "edit";
+pub const CMD_DOCS: &str = "docs";
+
+pub const FLAG_DEBUG: &str = "debug";
+pub const FLAG_OPTIMIZE: &str = "optimize";
+pub const ROC_FILE: &str = "ROC_FILE";
+pub const DIRECTORY_OR_FILES: &str = "DIRECTORY_OR_FILES";
+pub const ARGS_FOR_APP: &str = "ARGS_FOR_APP";
 
 pub fn build_app<'a>() -> App<'a> {
     App::new("roc")
         .version(crate_version!())
-        .subcommand(App::new("build")
+        .subcommand(App::new(CMD_BUILD)
             .about("Build a program")
             .arg(
-                Arg::with_name(FLAG_ROC_FILE)
+                Arg::with_name(ROC_FILE)
                     .help("The .roc file to build")
                     .required(true),
             )
@@ -44,13 +52,9 @@ pub fn build_app<'a>() -> App<'a> {
                     .required(false),
             )
         )
-        .subcommand(App::new("run")
+        .subcommand(App::new(CMD_RUN)
             .about("Build and run a program")
-            .arg(
-                Arg::with_name(FLAG_ROC_FILE)
-                    .help("The .roc file to build and run")
-                    .required(true),
-            )
+            .setting(AppSettings::TrailingVarArg)
             .arg(
                 Arg::with_name(FLAG_OPTIMIZE)
                     .long(FLAG_OPTIMIZE)
@@ -63,11 +67,21 @@ pub fn build_app<'a>() -> App<'a> {
                     .help("Store LLVM debug information in the generated program")
                     .required(false),
             )
+            .arg(
+                Arg::with_name(ROC_FILE)
+                    .help("The .roc file of an app to build and run")
+                    .required(true),
+            )
+            .arg(
+                Arg::with_name(ARGS_FOR_APP)
+                    .help("Arguments to pass into the app being run")
+                    .multiple(true),
+            )
         )
-        .subcommand(App::new("repl")
+        .subcommand(App::new(CMD_REPL)
             .about("Launch the interactive Read Eval Print Loop (REPL)")
         )
-        .subcommand(App::new("edit")
+        .subcommand(App::new(CMD_EDIT)
             .about("Launch the Roc editor")
             .arg(Arg::with_name(DIRECTORY_OR_FILES)
                 .index(1)
@@ -77,7 +91,7 @@ pub fn build_app<'a>() -> App<'a> {
             )
         )
         .subcommand(
-            App::new("docs")
+            App::new(CMD_DOCS)
                 .about("Generate documentation for Roc modules")
                 .arg(Arg::with_name(DIRECTORY_OR_FILES)
                     .index(1)
@@ -97,10 +111,18 @@ pub fn docs(files: Vec<PathBuf>) {
     )
 }
 
-pub fn build(target: &Triple, matches: &ArgMatches, run_after_build: bool) -> io::Result<()> {
-    let arena = Bump::new();
-    let filename = matches.value_of(FLAG_ROC_FILE).unwrap();
+pub enum BuildConfig {
+    BuildOnly,
+    BuildAndRun { roc_file_arg_index: usize },
+}
 
+pub fn build(target: &Triple, matches: &ArgMatches, config: BuildConfig) -> io::Result<i32> {
+    use BuildConfig::*;
+
+    let arena = Bump::new();
+    let filename = matches.value_of(ROC_FILE).unwrap();
+
+    let original_cwd = std::env::current_dir()?;
     let opt_level = if matches.is_present(FLAG_OPTIMIZE) {
         OptLevel::Optimize
     } else {
@@ -130,7 +152,7 @@ pub fn build(target: &Triple, matches: &ArgMatches, run_after_build: bool) -> io
         }
     });
 
-    let res_binary_path = build::build_file(
+    let res_binary_path = build_file(
         &arena,
         target,
         src_dir,
@@ -141,23 +163,77 @@ pub fn build(target: &Triple, matches: &ArgMatches, run_after_build: bool) -> io
     );
 
     match res_binary_path {
-        Ok(binary_path) => {
-            if run_after_build {
-                // Run the compiled app
-                Command::new(binary_path)
-                    .spawn()
-                    .unwrap_or_else(|err| panic!("Failed to run app after building it: {:?}", err))
-                    .wait()
-                    .expect("TODO gracefully handle block_on failing");
+        Ok(BuiltFile {
+            binary_path,
+            outcome,
+            total_time,
+        }) => {
+            match config {
+                BuildOnly => {
+                    // If possible, report the generated executable name relative to the current dir.
+                    let generated_filename = binary_path
+                        .strip_prefix(env::current_dir().unwrap())
+                        .unwrap_or(&binary_path);
+
+                    println!(
+                        "🎉 Built {} in {} ms",
+                        generated_filename.to_str().unwrap(),
+                        total_time.as_millis()
+                    );
+
+                    // Return a nonzero exit code if there were problems
+                    let status_code = match outcome {
+                        BuildOutcome::NoProblems => 0,
+                        BuildOutcome::OnlyWarnings => 1,
+                        BuildOutcome::Errors => 2,
+                    };
+
+                    Ok(status_code)
+                }
+                BuildAndRun { roc_file_arg_index } => {
+                    let mut cmd = Command::new(binary_path);
+
+                    // Forward all the arguments after the .roc file argument
+                    // to the new process. This way, you can do things like:
+                    //
+                    // roc run app.roc foo bar baz
+                    //
+                    // ...and have it so that app.roc will receive only `foo`,
+                    // `bar`, and `baz` as its arguments.
+                    for (index, arg) in std::env::args().enumerate() {
+                        if index > roc_file_arg_index {
+                            cmd.arg(arg);
+                        }
+                    }
+
+                    // Run the compiled app
+                    let exit_status = cmd
+                        .current_dir(original_cwd)
+                        .spawn()
+                        .unwrap_or_else(|err| panic!("Failed to run app after building it: {:?}", err))
+                        .wait()
+                        .expect("TODO gracefully handle block_on failing when roc run spawns a subprocess for the compiled app");
+
+                    // `roc run` exits with the same status code as the app it ran.
+                    //
+                    // If you want to know whether there were compilation problems
+                    // via status code, use either `roc build` or `roc check` instead!
+                    match exit_status.code() {
+                        Some(code) => Ok(code),
+                        None => {
+                            todo!("TODO gracefully handle the roc run subprocess terminating with a signal.");
+                        }
+                    }
+                }
             }
         }
         Err(LoadingProblem::FormattedReport(report)) => {
             print!("{}", report);
+
+            Ok(1)
         }
         Err(other) => {
             panic!("build_file failed with error:\n{:?}", other);
         }
     }
-
-    Ok(())
 }

cli/src/main.rs

@@ -1,4 +1,7 @@
-use roc_cli::{build, build_app, docs, repl, DIRECTORY_OR_FILES};
+use roc_cli::{
+    build, build_app, docs, repl, BuildConfig, CMD_BUILD, CMD_DOCS, CMD_EDIT, CMD_REPL, CMD_RUN,
+    DIRECTORY_OR_FILES, ROC_FILE,
+};
 use std::io;
 use std::path::{Path, PathBuf};
 use target_lexicon::Triple;
@@ -6,38 +9,58 @@ use target_lexicon::Triple;
 fn main() -> io::Result<()> {
     let matches = build_app().get_matches();
 
-    match matches.subcommand_name() {
-        None => roc_editor::launch(&[]),
-        Some("build") => build(
+    let exit_code = match matches.subcommand_name() {
+        None => {
+            roc_editor::launch(&[])?;
+
+            // rustc couldn't infer the error type here
+            Result::<i32, io::Error>::Ok(0)
+        }
+        Some(CMD_BUILD) => Ok(build(
             &Triple::host(),
-            matches.subcommand_matches("build").unwrap(),
-            false,
-        ),
-        Some("run") => build(
-            &Triple::host(),
-            matches.subcommand_matches("run").unwrap(),
-            true,
-        ),
-        Some("repl") => repl::main(),
-        Some("edit") => {
+            matches.subcommand_matches(CMD_BUILD).unwrap(),
+            BuildConfig::BuildOnly,
+        )?),
+        Some(CMD_RUN) => {
+            let subcmd_matches = matches.subcommand_matches(CMD_RUN).unwrap();
+            let roc_file_arg_index = subcmd_matches.index_of(ROC_FILE).unwrap() + 1; // Not sure why this +1 is necessary, but it is!
+
+            Ok(build(
+                &Triple::host(),
+                subcmd_matches,
+                BuildConfig::BuildAndRun { roc_file_arg_index },
+            )?)
+        }
+        Some(CMD_REPL) => {
+            repl::main()?;
+
+            // Exit 0 if the repl exited normally
+            Ok(0)
+        }
+        Some(CMD_EDIT) => {
             match matches
-                .subcommand_matches("edit")
+                .subcommand_matches(CMD_EDIT)
                 .unwrap()
                 .values_of_os(DIRECTORY_OR_FILES)
             {
-                None => roc_editor::launch(&[]),
+                None => {
+                    roc_editor::launch(&[])?;
+                }
                 Some(values) => {
                     let paths = values
                         .map(|os_str| Path::new(os_str))
                         .collect::<Vec<&Path>>();
 
-                    roc_editor::launch(&paths)
+                    roc_editor::launch(&paths)?;
                 }
             }
+
+            // Exit 0 if the editor exited normally
+            Ok(0)
         }
-        Some("docs") => {
+        Some(CMD_DOCS) => {
             let values = matches
-                .subcommand_matches("docs")
+                .subcommand_matches(CMD_DOCS)
                 .unwrap()
                 .values_of_os(DIRECTORY_OR_FILES)
                 .unwrap();
@@ -48,8 +71,10 @@ fn main() -> io::Result<()> {
 
             docs(paths);
 
-            Ok(())
+            Ok(0)
         }
         _ => unreachable!(),
-    }
+    }?;
+
+    std::process::exit(exit_code);
 }

examples/cli/platform/src/lib.rs

@@ -2,7 +2,6 @@
 
 use roc_std::{alloca, RocCallResult, RocResult, RocStr};
 use std::alloc::Layout;
-use std::time::SystemTime;
 
 extern "C" {
     #[link_name = "roc__mainForHost_1_exposed"]