Early implementation of bash-like completions with 'complete' and 'compgen' builtins

src/builtin/complete.rs

@@ -0,0 +1,248 @@
+use bitflags::bitflags;
+use nix::{libc::STDOUT_FILENO, unistd::write};
+
+use crate::{builtin::setup_builtin, getopt::{Opt, OptSpec, get_opts_from_tokens}, jobs::JobBldr, libsh::error::{ShErr, ShErrKind, ShResult}, parse::{NdRule, Node}, procio::{IoStack, borrow_fd}, readline::complete::{BashCompSpec, CompContext, CompSpec}, state::{self, read_meta, write_meta}};
+
+pub const COMPGEN_OPTS: [OptSpec;7] = [
+	OptSpec {
+		opt: Opt::Short('F'),
+		takes_arg: true
+	},
+	OptSpec {
+		opt: Opt::Short('W'),
+		takes_arg: true
+	},
+	OptSpec {
+		opt: Opt::Short('f'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('d'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('c'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('u'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('v'),
+		takes_arg: false
+	}
+];
+
+pub const COMP_OPTS: [OptSpec;10] = [
+	OptSpec {
+		opt: Opt::Short('F'),
+		takes_arg: true
+	},
+	OptSpec {
+		opt: Opt::Short('W'),
+		takes_arg: true
+	},
+	OptSpec {
+		opt: Opt::Short('A'),
+		takes_arg: true
+	},
+	OptSpec {
+		opt: Opt::Short('p'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('r'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('f'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('d'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('c'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('u'),
+		takes_arg: false
+	},
+	OptSpec {
+		opt: Opt::Short('v'),
+		takes_arg: false
+	}
+];
+
+bitflags! {
+	#[derive(Default, Debug, Clone, Copy, PartialEq, Eq, Hash)]
+	pub struct CompFlags: u32 {
+		const FILES  = 0b0000000001;
+		const DIRS   = 0b0000000010;
+		const CMDS   = 0b0000000100;
+		const USERS  = 0b0000001000;
+		const VARS   = 0b0000010000;
+		const PRINT  = 0b0000100000;
+		const REMOVE = 0b0001000000;
+	}
+}
+
+#[derive(Default, Debug, Clone)]
+pub struct CompOpts {
+	pub func: Option<String>,
+	pub wordlist: Option<Vec<String>>,
+	pub action: Option<String>,
+	pub flags: CompFlags
+}
+
+pub fn complete_builtin(node: Node, io_stack: &mut IoStack, job: &mut JobBldr) -> ShResult<()> {
+	let blame = node.get_span().clone();
+  let NdRule::Command {
+    assignments: _,
+    argv,
+  } = node.class
+  else {
+    unreachable!()
+  };
+  assert!(!argv.is_empty());
+	let src = argv.clone()
+		.into_iter()
+		.map(|tk| tk.expand().map(|tk| tk.get_words().join(" ")))
+		.collect::<ShResult<Vec<String>>>()?
+		.join(" ");
+
+  let (argv, opts) = get_opts_from_tokens(argv, &COMP_OPTS)?;
+	let comp_opts = get_comp_opts(opts)?;
+	let (argv, _) = setup_builtin(argv, job, Some((io_stack, node.redirs)))?;
+
+	if comp_opts.flags.contains(CompFlags::PRINT) {
+		if argv.is_empty() {
+			read_meta(|m| {
+				let specs = m.comp_specs().values();
+				for spec in specs {
+					println!("{}", spec.source());
+				}
+			})
+		} else {
+			read_meta(|m| {
+				for (cmd,_) in &argv {
+					if let Some(spec) = m.comp_specs().get(cmd) {
+						println!("{}", spec.source());
+					}
+				}
+			})
+		}
+
+		state::set_status(0);
+		return Ok(());
+	}
+
+	if comp_opts.flags.contains(CompFlags::REMOVE) {
+		write_meta(|m| {
+			for (cmd,_) in &argv {
+				m.remove_comp_spec(cmd);
+			}
+		});
+
+		state::set_status(0);
+		return Ok(());
+	}
+
+	if argv.is_empty() {
+		state::set_status(1);
+		return Err(ShErr::full(ShErrKind::ExecFail, "complete: no command specified", blame));
+	}
+
+	let comp_spec = BashCompSpec::from_comp_opts(comp_opts)
+		.with_source(src);
+
+	for (cmd,_) in argv {
+		write_meta(|m| m.set_comp_spec(cmd, Box::new(comp_spec.clone())));
+	}
+
+	state::set_status(0);
+	Ok(())
+}
+
+pub fn compgen_builtin(node: Node, io_stack: &mut IoStack, job: &mut JobBldr) -> ShResult<()> {
+	let blame = node.get_span().clone();
+	let NdRule::Command {
+		assignments: _,
+		argv,
+	} = node.class
+	else {
+		unreachable!()
+	};
+	assert!(!argv.is_empty());
+	let src = argv.clone()
+		.into_iter()
+		.map(|tk| tk.expand().map(|tk| tk.get_words().join(" ")))
+		.collect::<ShResult<Vec<String>>>()?
+		.join(" ");
+
+	let (argv, opts) = get_opts_from_tokens(argv, &COMPGEN_OPTS)?;
+	let prefix = argv
+		.clone()
+		.into_iter()
+		.nth(1)
+		.unwrap_or_default();
+	let comp_opts = get_comp_opts(opts)?;
+	let (_, _guard) = setup_builtin(argv, job, Some((io_stack, node.redirs)))?;
+
+
+	let comp_spec = BashCompSpec::from_comp_opts(comp_opts)
+		.with_source(src);
+
+	log::debug!("compgen: prefix='{}', spec={:?}", prefix.as_str(), comp_spec);
+
+	let dummy_ctx = CompContext {
+		words: vec![prefix.clone()],
+		cword: 0,
+		line: prefix.to_string(),
+		cursor_pos: prefix.as_str().len()
+	};
+
+	let results = comp_spec.complete(&dummy_ctx)?;
+	log::debug!("compgen: {} results: {:?}", results.len(), results);
+
+	let stdout = borrow_fd(STDOUT_FILENO);
+	for result in &results {
+		write(stdout, result.as_bytes())?;
+		write(stdout, b"\n")?;
+	}
+
+	state::set_status(0);
+	Ok(())
+}
+
+pub fn get_comp_opts(opts: Vec<Opt>) -> ShResult<CompOpts> {
+	let mut comp_opts = CompOpts::default();
+
+	for opt in opts {
+		match opt {
+			Opt::ShortWithArg('F',func) => {
+				comp_opts.func = Some(func);
+			},
+			Opt::ShortWithArg('W',wordlist) => {
+				comp_opts.wordlist = Some(wordlist.split_whitespace().map(|s| s.to_string()).collect());
+			},
+			Opt::ShortWithArg('A',action) => {
+				comp_opts.action = Some(action);
+			}
+
+			Opt::Short('r') => comp_opts.flags |= CompFlags::REMOVE,
+			Opt::Short('p') => comp_opts.flags |= CompFlags::PRINT,
+			Opt::Short('f') => comp_opts.flags |= CompFlags::FILES,
+			Opt::Short('d') => comp_opts.flags |= CompFlags::DIRS,
+			Opt::Short('c') => comp_opts.flags |= CompFlags::CMDS,
+			Opt::Short('u') => comp_opts.flags |= CompFlags::USERS,
+			Opt::Short('v') => comp_opts.flags |= CompFlags::VARS,
+			_ => unreachable!()
+		}
+	}
+
+	Ok(comp_opts)
+}