Mercurial > hg
view rust/rhg/src/main.rs @ 48731:f591b377375f
rhg: Make Ui::new falliable, add Ui::new_infallible
This allows propagating color configuration errors
Differential Revision: https://phab.mercurial-scm.org/D12165
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Thu, 10 Feb 2022 12:52:25 +0100 |
parents | 1aaf11e35aec |
children | d4a5c2197208 |
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extern crate log; use crate::error::CommandError; use crate::ui::Ui; use clap::App; use clap::AppSettings; use clap::Arg; use clap::ArgMatches; use format_bytes::{format_bytes, join}; use hg::config::{Config, ConfigSource}; use hg::exit_codes; use hg::repo::{Repo, RepoError}; use hg::utils::files::{get_bytes_from_os_str, get_path_from_bytes}; use hg::utils::SliceExt; use std::collections::HashSet; use std::ffi::OsString; use std::path::PathBuf; use std::process::Command; mod blackbox; mod error; mod ui; pub mod utils { pub mod path_utils; } fn main_with_result( process_start_time: &blackbox::ProcessStartTime, ui: &ui::Ui, repo: Result<&Repo, &NoRepoInCwdError>, config: &Config, ) -> Result<(), CommandError> { check_unsupported(config, repo, ui)?; let app = App::new("rhg") .global_setting(AppSettings::AllowInvalidUtf8) .global_setting(AppSettings::DisableVersion) .setting(AppSettings::SubcommandRequired) .setting(AppSettings::VersionlessSubcommands) .arg( Arg::with_name("repository") .help("repository root directory") .short("-R") .long("--repository") .value_name("REPO") .takes_value(true) // Both ok: `hg -R ./foo log` or `hg log -R ./foo` .global(true), ) .arg( Arg::with_name("config") .help("set/override config option (use 'section.name=value')") .long("--config") .value_name("CONFIG") .takes_value(true) .global(true) // Ok: `--config section.key1=val --config section.key2=val2` .multiple(true) // Not ok: `--config section.key1=val section.key2=val2` .number_of_values(1), ) .arg( Arg::with_name("cwd") .help("change working directory") .long("--cwd") .value_name("DIR") .takes_value(true) .global(true), ) .version("0.0.1"); let app = add_subcommand_args(app); let matches = app.clone().get_matches_safe()?; let (subcommand_name, subcommand_matches) = matches.subcommand(); // Mercurial allows users to define "defaults" for commands, fallback // if a default is detected for the current command let defaults = config.get_str(b"defaults", subcommand_name.as_bytes()); if defaults?.is_some() { let msg = "`defaults` config set"; return Err(CommandError::unsupported(msg)); } for prefix in ["pre", "post", "fail"].iter() { // Mercurial allows users to define generic hooks for commands, // fallback if any are detected let item = format!("{}-{}", prefix, subcommand_name); let hook_for_command = config.get_str(b"hooks", item.as_bytes())?; if hook_for_command.is_some() { let msg = format!("{}-{} hook defined", prefix, subcommand_name); return Err(CommandError::unsupported(msg)); } } let run = subcommand_run_fn(subcommand_name) .expect("unknown subcommand name from clap despite AppSettings::SubcommandRequired"); let subcommand_args = subcommand_matches .expect("no subcommand arguments from clap despite AppSettings::SubcommandRequired"); let invocation = CliInvocation { ui, subcommand_args, config, repo, }; if let Ok(repo) = repo { // We don't support subrepos, fallback if the subrepos file is present if repo.working_directory_vfs().join(".hgsub").exists() { let msg = "subrepos (.hgsub is present)"; return Err(CommandError::unsupported(msg)); } } if config.is_extension_enabled(b"blackbox") { let blackbox = blackbox::Blackbox::new(&invocation, process_start_time)?; blackbox.log_command_start(); let result = run(&invocation); blackbox.log_command_end(exit_code( &result, // TODO: show a warning or combine with original error if // `get_bool` returns an error config .get_bool(b"ui", b"detailed-exit-code") .unwrap_or(false), )); result } else { run(&invocation) } } fn main() { // Run this first, before we find out if the blackbox extension is even // enabled, in order to include everything in-between in the duration // measurements. Reading config files can be slow if they’re on NFS. let process_start_time = blackbox::ProcessStartTime::now(); env_logger::init(); let early_args = EarlyArgs::parse(std::env::args_os()); let initial_current_dir = early_args.cwd.map(|cwd| { let cwd = get_path_from_bytes(&cwd); std::env::current_dir() .and_then(|initial| { std::env::set_current_dir(cwd)?; Ok(initial) }) .unwrap_or_else(|error| { exit( &None, &Ui::new_infallible(&Config::empty()), OnUnsupported::Abort, Err(CommandError::abort(format!( "abort: {}: '{}'", error, cwd.display() ))), false, ) }) }); let mut non_repo_config = Config::load_non_repo().unwrap_or_else(|error| { // Normally this is decided based on config, but we don’t have that // available. As of this writing config loading never returns an // "unsupported" error but that is not enforced by the type system. let on_unsupported = OnUnsupported::Abort; exit( &initial_current_dir, &Ui::new_infallible(&Config::empty()), on_unsupported, Err(error.into()), false, ) }); non_repo_config .load_cli_args_config(early_args.config) .unwrap_or_else(|error| { exit( &initial_current_dir, &Ui::new_infallible(&non_repo_config), OnUnsupported::from_config(&non_repo_config), Err(error.into()), non_repo_config .get_bool(b"ui", b"detailed-exit-code") .unwrap_or(false), ) }); if let Some(repo_path_bytes) = &early_args.repo { lazy_static::lazy_static! { static ref SCHEME_RE: regex::bytes::Regex = // Same as `_matchscheme` in `mercurial/util.py` regex::bytes::Regex::new("^[a-zA-Z0-9+.\\-]+:").unwrap(); } if SCHEME_RE.is_match(&repo_path_bytes) { exit( &initial_current_dir, &Ui::new_infallible(&non_repo_config), OnUnsupported::from_config(&non_repo_config), Err(CommandError::UnsupportedFeature { message: format_bytes!( b"URL-like --repository {}", repo_path_bytes ), }), // TODO: show a warning or combine with original error if // `get_bool` returns an error non_repo_config .get_bool(b"ui", b"detailed-exit-code") .unwrap_or(false), ) } } let repo_arg = early_args.repo.unwrap_or(Vec::new()); let repo_path: Option<PathBuf> = { if repo_arg.is_empty() { None } else { let local_config = { if std::env::var_os("HGRCSKIPREPO").is_none() { // TODO: handle errors from find_repo_root if let Ok(current_dir_path) = Repo::find_repo_root() { let config_files = vec![ ConfigSource::AbsPath( current_dir_path.join(".hg/hgrc"), ), ConfigSource::AbsPath( current_dir_path.join(".hg/hgrc-not-shared"), ), ]; // TODO: handle errors from // `load_from_explicit_sources` Config::load_from_explicit_sources(config_files).ok() } else { None } } else { None } }; let non_repo_config_val = { let non_repo_val = non_repo_config.get(b"paths", &repo_arg); match &non_repo_val { Some(val) if val.len() > 0 => home::home_dir() .unwrap_or_else(|| PathBuf::from("~")) .join(get_path_from_bytes(val)) .canonicalize() // TODO: handle error and make it similar to python // implementation maybe? .ok(), _ => None, } }; let config_val = match &local_config { None => non_repo_config_val, Some(val) => { let local_config_val = val.get(b"paths", &repo_arg); match &local_config_val { Some(val) if val.len() > 0 => { // presence of a local_config assures that // current_dir // wont result in an Error let canpath = hg::utils::current_dir() .unwrap() .join(get_path_from_bytes(val)) .canonicalize(); canpath.ok().or(non_repo_config_val) } _ => non_repo_config_val, } } }; config_val.or(Some(get_path_from_bytes(&repo_arg).to_path_buf())) } }; let repo_result = match Repo::find(&non_repo_config, repo_path.to_owned()) { Ok(repo) => Ok(repo), Err(RepoError::NotFound { at }) if repo_path.is_none() => { // Not finding a repo is not fatal yet, if `-R` was not given Err(NoRepoInCwdError { cwd: at }) } Err(error) => exit( &initial_current_dir, &Ui::new_infallible(&non_repo_config), OnUnsupported::from_config(&non_repo_config), Err(error.into()), // TODO: show a warning or combine with original error if // `get_bool` returns an error non_repo_config .get_bool(b"ui", b"detailed-exit-code") .unwrap_or(false), ), }; let config = if let Ok(repo) = &repo_result { repo.config() } else { &non_repo_config }; let ui = Ui::new(&config).unwrap_or_else(|error| { exit( &initial_current_dir, &Ui::new_infallible(&config), OnUnsupported::from_config(&config), Err(error.into()), config .get_bool(b"ui", b"detailed-exit-code") .unwrap_or(false), ) }); let on_unsupported = OnUnsupported::from_config(config); let result = main_with_result( &process_start_time, &ui, repo_result.as_ref(), config, ); exit( &initial_current_dir, &ui, on_unsupported, result, // TODO: show a warning or combine with original error if `get_bool` // returns an error config .get_bool(b"ui", b"detailed-exit-code") .unwrap_or(false), ) } fn exit_code( result: &Result<(), CommandError>, use_detailed_exit_code: bool, ) -> i32 { match result { Ok(()) => exit_codes::OK, Err(CommandError::Abort { message: _, detailed_exit_code, }) => { if use_detailed_exit_code { *detailed_exit_code } else { exit_codes::ABORT } } Err(CommandError::Unsuccessful) => exit_codes::UNSUCCESSFUL, // Exit with a specific code and no error message to let a potential // wrapper script fallback to Python-based Mercurial. Err(CommandError::UnsupportedFeature { .. }) => { exit_codes::UNIMPLEMENTED } } } fn exit( initial_current_dir: &Option<PathBuf>, ui: &Ui, mut on_unsupported: OnUnsupported, result: Result<(), CommandError>, use_detailed_exit_code: bool, ) -> ! { if let ( OnUnsupported::Fallback { executable }, Err(CommandError::UnsupportedFeature { .. }), ) = (&on_unsupported, &result) { let mut args = std::env::args_os(); let executable = match executable { None => { exit_no_fallback( ui, OnUnsupported::Abort, Err(CommandError::abort( "abort: 'rhg.on-unsupported=fallback' without \ 'rhg.fallback-executable' set.", )), false, ); } Some(executable) => executable, }; let executable_path = get_path_from_bytes(&executable); let this_executable = args.next().expect("exepcted argv[0] to exist"); if executable_path == &PathBuf::from(this_executable) { // Avoid spawning infinitely many processes until resource // exhaustion. let _ = ui.write_stderr(&format_bytes!( b"Blocking recursive fallback. The 'rhg.fallback-executable = {}' config \ points to `rhg` itself.\n", executable )); on_unsupported = OnUnsupported::Abort } else { // `args` is now `argv[1..]` since we’ve already consumed // `argv[0]` let mut command = Command::new(executable_path); command.args(args); if let Some(initial) = initial_current_dir { command.current_dir(initial); } let result = command.status(); match result { Ok(status) => std::process::exit( status.code().unwrap_or(exit_codes::ABORT), ), Err(error) => { let _ = ui.write_stderr(&format_bytes!( b"tried to fall back to a '{}' sub-process but got error {}\n", executable, format_bytes::Utf8(error) )); on_unsupported = OnUnsupported::Abort } } } } exit_no_fallback(ui, on_unsupported, result, use_detailed_exit_code) } fn exit_no_fallback( ui: &Ui, on_unsupported: OnUnsupported, result: Result<(), CommandError>, use_detailed_exit_code: bool, ) -> ! { match &result { Ok(_) => {} Err(CommandError::Unsuccessful) => {} Err(CommandError::Abort { message, detailed_exit_code: _, }) => { if !message.is_empty() { // Ignore errors when writing to stderr, we’re already exiting // with failure code so there’s not much more we can do. let _ = ui.write_stderr(&format_bytes!(b"{}\n", message)); } } Err(CommandError::UnsupportedFeature { message }) => { match on_unsupported { OnUnsupported::Abort => { let _ = ui.write_stderr(&format_bytes!( b"unsupported feature: {}\n", message )); } OnUnsupported::AbortSilent => {} OnUnsupported::Fallback { .. } => unreachable!(), } } } std::process::exit(exit_code(&result, use_detailed_exit_code)) } macro_rules! subcommands { ($( $command: ident )+) => { mod commands { $( pub mod $command; )+ } fn add_subcommand_args<'a, 'b>(app: App<'a, 'b>) -> App<'a, 'b> { app $( .subcommand(commands::$command::args()) )+ } pub type RunFn = fn(&CliInvocation) -> Result<(), CommandError>; fn subcommand_run_fn(name: &str) -> Option<RunFn> { match name { $( stringify!($command) => Some(commands::$command::run), )+ _ => None, } } }; } subcommands! { cat debugdata debugrequirements debugignorerhg files root config status } pub struct CliInvocation<'a> { ui: &'a Ui, subcommand_args: &'a ArgMatches<'a>, config: &'a Config, /// References inside `Result` is a bit peculiar but allow /// `invocation.repo?` to work out with `&CliInvocation` since this /// `Result` type is `Copy`. repo: Result<&'a Repo, &'a NoRepoInCwdError>, } struct NoRepoInCwdError { cwd: PathBuf, } /// CLI arguments to be parsed "early" in order to be able to read /// configuration before using Clap. Ideally we would also use Clap for this, /// see <https://github.com/clap-rs/clap/discussions/2366>. /// /// These arguments are still declared when we do use Clap later, so that Clap /// does not return an error for their presence. struct EarlyArgs { /// Values of all `--config` arguments. (Possibly none) config: Vec<Vec<u8>>, /// Value of the `-R` or `--repository` argument, if any. repo: Option<Vec<u8>>, /// Value of the `--cwd` argument, if any. cwd: Option<Vec<u8>>, } impl EarlyArgs { fn parse(args: impl IntoIterator<Item = OsString>) -> Self { let mut args = args.into_iter().map(get_bytes_from_os_str); let mut config = Vec::new(); let mut repo = None; let mut cwd = None; // Use `while let` instead of `for` so that we can also call // `args.next()` inside the loop. while let Some(arg) = args.next() { if arg == b"--config" { if let Some(value) = args.next() { config.push(value) } } else if let Some(value) = arg.drop_prefix(b"--config=") { config.push(value.to_owned()) } if arg == b"--cwd" { if let Some(value) = args.next() { cwd = Some(value) } } else if let Some(value) = arg.drop_prefix(b"--cwd=") { cwd = Some(value.to_owned()) } if arg == b"--repository" || arg == b"-R" { if let Some(value) = args.next() { repo = Some(value) } } else if let Some(value) = arg.drop_prefix(b"--repository=") { repo = Some(value.to_owned()) } else if let Some(value) = arg.drop_prefix(b"-R") { repo = Some(value.to_owned()) } } Self { config, repo, cwd } } } /// What to do when encountering some unsupported feature. /// /// See `HgError::UnsupportedFeature` and `CommandError::UnsupportedFeature`. enum OnUnsupported { /// Print an error message describing what feature is not supported, /// and exit with code 252. Abort, /// Silently exit with code 252. AbortSilent, /// Try running a Python implementation Fallback { executable: Option<Vec<u8>> }, } impl OnUnsupported { const DEFAULT: Self = OnUnsupported::Abort; fn from_config(config: &Config) -> Self { match config .get(b"rhg", b"on-unsupported") .map(|value| value.to_ascii_lowercase()) .as_deref() { Some(b"abort") => OnUnsupported::Abort, Some(b"abort-silent") => OnUnsupported::AbortSilent, Some(b"fallback") => OnUnsupported::Fallback { executable: config .get(b"rhg", b"fallback-executable") .map(|x| x.to_owned()), }, None => Self::DEFAULT, Some(_) => { // TODO: warn about unknown config value Self::DEFAULT } } } } /// The `*` extension is an edge-case for config sub-options that apply to all /// extensions. For now, only `:required` exists, but that may change in the /// future. const SUPPORTED_EXTENSIONS: &[&[u8]] = &[b"blackbox", b"share", b"sparse", b"narrow", b"*"]; fn check_extensions(config: &Config) -> Result<(), CommandError> { let enabled: HashSet<&[u8]> = config .get_section_keys(b"extensions") .into_iter() .map(|extension| { // Ignore extension suboptions. Only `required` exists for now. // `rhg` either supports an extension or doesn't, so it doesn't // make sense to consider the loading of an extension. extension.split_2(b':').unwrap_or((extension, b"")).0 }) .collect(); let mut unsupported = enabled; for supported in SUPPORTED_EXTENSIONS { unsupported.remove(supported); } if let Some(ignored_list) = config.get_list(b"rhg", b"ignored-extensions") { for ignored in ignored_list { unsupported.remove(ignored.as_slice()); } } if unsupported.is_empty() { Ok(()) } else { Err(CommandError::UnsupportedFeature { message: format_bytes!( b"extensions: {} (consider adding them to 'rhg.ignored-extensions' config)", join(unsupported, b", ") ), }) } } fn check_unsupported( config: &Config, repo: Result<&Repo, &NoRepoInCwdError>, ui: &ui::Ui, ) -> Result<(), CommandError> { check_extensions(config)?; if std::env::var_os("HG_PENDING").is_some() { // TODO: only if the value is `== repo.working_directory`? // What about relative v.s. absolute paths? Err(CommandError::unsupported("$HG_PENDING"))? } if let Ok(repo) = repo { if repo.has_subrepos()? { Err(CommandError::unsupported("sub-repositories"))? } } if config.has_non_empty_section(b"encode") { Err(CommandError::unsupported("[encode] config"))? } if config.has_non_empty_section(b"decode") { Err(CommandError::unsupported("[decode] config"))? } if let Some(color) = config.get(b"ui", b"color") { if (color == b"always" || color == b"debug") && !ui.plain(Some("color")) { Err(CommandError::unsupported("colored output"))? } } Ok(()) }