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6006244739b4775cbb13fb841eb004148eaa5b3b
shed/src/parse/mod.rs

1565 lines
39 KiB
Rust
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use std::str::FromStr;
use bitflags::bitflags;
use fmt::Display;
use lex::{LexFlags, LexStream, Span, Tk, TkFlags, TkRule};
use crate::{libsh::{error::{Note, ShErr, ShErrKind, ShResult}, utils::TkVecUtils}, prelude::*, procio::IoMode};
pub mod lex;
pub mod execute;
pub const TEST_UNARY_OPS: [&str; 21] = [
"-a",
"-b",
"-c",
"-d",
"-e",
"-f",
"-g",
"-h",
"-L",
"-k",
"-p",
"-r",
"-s",
"-S",
"-t",
"-u",
"-w",
"-x",
"-O",
"-G",
"-N",
];
/// Try to match a specific parsing rule
///
/// # Notes
/// * If the match fails, execution continues.
/// * If the match succeeds, the matched node is returned.
macro_rules! try_match {
($expr:expr) => {
if let Some(node) = $expr {
return Ok(Some(node))
}
};
}
/// The parsed AST along with the source input it parsed
///
/// Uses Arc<String> instead of &str because the reference has to stay alive while errors are propagated upwards
/// The string also has to stay alive in the case of pre-parsed shell function nodes, which live in the logic table
/// Using &str for this use-case dramatically overcomplicates the code
#[derive(Clone,Debug)]
pub struct ParsedSrc {
pub src: Arc<String>,
pub ast: Ast
}
impl ParsedSrc {
pub fn new(src: Arc<String>) -> Self {
Self { src, ast: Ast::new(vec![]) }
}
pub fn parse_src(&mut self) -> Result<(),Vec<ShErr>> {
let mut tokens = vec![];
for lex_result in LexStream::new(self.src.clone(), LexFlags::empty()) {
match lex_result {
Ok(token) => tokens.push(token),
Err(error) => return Err(vec![error])
}
}
let mut errors = vec![];
let mut nodes = vec![];
for parse_result in ParseStream::new(tokens) {
match parse_result {
Ok(node) => nodes.push(node),
Err(error) => errors.push(error)
}
}
if !errors.is_empty() {
return Err(errors)
}
*self.ast.tree_mut() = nodes;
Ok(())
}
pub fn extract_nodes(&mut self) -> Vec<Node> {
mem::take(self.ast.tree_mut())
}
}
#[derive(Clone,Debug)]
pub struct Ast(Vec<Node>);
impl Ast {
pub fn new(tree: Vec<Node>) -> Self {
Self(tree)
}
pub fn into_inner(self) -> Vec<Node> {
self.0
}
pub fn tree_mut(&mut self) -> &mut Vec<Node> {
&mut self.0
}
}
#[derive(Clone,Debug)]
pub struct Node {
pub class: NdRule,
pub flags: NdFlags,
pub redirs: Vec<Redir>,
pub tokens: Vec<Tk>,
}
impl Node {
pub fn get_command(&self) -> Option<&Tk> {
let NdRule::Command { assignments: _, argv } = &self.class else {
return None
};
let command = argv.iter().find(|tk| tk.flags.contains(TkFlags::IS_CMD))?;
Some(command)
}
pub fn get_span(&self) -> Span {
let Some(first_tk) = self.tokens.first() else {
unreachable!()
};
let Some(last_tk) = self.tokens.last() else {
unreachable!()
};
Span::new(first_tk.span.start..last_tk.span.end, first_tk.span.get_source())
}
}
bitflags! {
#[derive(Clone,Copy,Debug)]
pub struct NdFlags: u32 {
const BACKGROUND = 0b000001;
}
}
#[derive(Clone,Debug)]
pub struct Redir {
pub io_mode: IoMode,
pub class: RedirType
}
impl Redir {
pub fn new(io_mode: IoMode, class: RedirType) -> Self {
Self { io_mode, class }
}
}
#[derive(Default,Debug)]
pub struct RedirBldr {
pub io_mode: Option<IoMode>,
pub class: Option<RedirType>,
pub tgt_fd: Option<RawFd>,
}
impl RedirBldr {
pub fn new() -> Self {
Default::default()
}
pub fn with_io_mode(self, io_mode: IoMode) -> Self {
let Self { io_mode: _, class, tgt_fd } = self;
Self { io_mode: Some(io_mode), class, tgt_fd }
}
pub fn with_class(self, class: RedirType) -> Self {
let Self { io_mode, class: _, tgt_fd } = self;
Self { io_mode, class: Some(class), tgt_fd }
}
pub fn with_tgt(self, tgt_fd: RawFd) -> Self {
let Self { io_mode, class, tgt_fd: _ } = self;
Self { io_mode, class, tgt_fd: Some(tgt_fd) }
}
pub fn build(self) -> Redir {
Redir::new(self.io_mode.unwrap(), self.class.unwrap())
}
}
impl FromStr for RedirBldr {
type Err = ();
fn from_str(s: &str) -> Result<Self, Self::Err> {
let mut chars = s.chars().peekable();
let mut src_fd = String::new();
let mut tgt_fd = String::new();
let mut redir = RedirBldr::new();
while let Some(ch) = chars.next() {
match ch {
'>' => {
redir = redir.with_class(RedirType::Output);
if let Some('>') = chars.peek() {
chars.next();
redir = redir.with_class(RedirType::Append);
}
}
'<' => {
redir = redir.with_class(RedirType::Input);
let mut count = 0;
while count < 2 && matches!(chars.peek(), Some('<')) {
chars.next();
count += 1;
}
redir = match count {
1 => redir.with_class(RedirType::HereDoc),
2 => redir.with_class(RedirType::HereString),
_ => redir, // Default case remains RedirType::Input
};
}
'&' => {
while let Some(next_ch) = chars.next() {
if next_ch.is_ascii_digit() {
src_fd.push(next_ch)
} else {
break
}
}
if src_fd.is_empty() {
return Err(())
}
}
_ if ch.is_ascii_digit() && tgt_fd.is_empty() => {
tgt_fd.push(ch);
while let Some(next_ch) = chars.peek() {
if next_ch.is_ascii_digit() {
let next_ch = chars.next().unwrap();
tgt_fd.push(next_ch);
} else {
break
}
}
}
_ => return Err(())
}
}
// FIXME: I am 99.999999999% sure that tgt_fd and src_fd are backwards here
let tgt_fd = tgt_fd.parse::<i32>().unwrap_or_else(|_| {
match redir.class.unwrap() {
RedirType::Input |
RedirType::HereDoc |
RedirType::HereString => 0,
_ => 1
}
});
redir = redir.with_tgt(tgt_fd);
if let Ok(src_fd) = src_fd.parse::<i32>() {
let io_mode = IoMode::fd(tgt_fd, src_fd);
redir = redir.with_io_mode(io_mode);
}
Ok(redir)
}
}
#[derive(PartialEq,Clone,Copy,Debug)]
pub enum RedirType {
Null, // Default
Pipe, // |
PipeAnd, // |&, redirs stderr and stdout
Input, // <
Output, // >
Append, // >>
HereDoc, // <<
HereString, // <<<
}
#[derive(Clone,Debug)]
pub struct CondNode {
pub cond: Box<Node>,
pub body: Vec<Node>
}
#[derive(Clone,Debug)]
pub struct CaseNode {
pub pattern: Tk,
pub body: Vec<Node>
}
#[derive(Clone,Copy,PartialEq,Debug)]
pub enum ConjunctOp {
And,
Or,
Null
}
#[derive(Clone,Debug)]
pub struct ConjunctNode {
pub cmd: Box<Node>,
pub operator: ConjunctOp
}
#[derive(Clone,Copy,Debug)]
pub enum LoopKind {
While,
Until
}
#[derive(Clone,Debug)]
pub enum TestCase {
Unary {
operator: Tk,
operand: Tk,
conjunct: Option<ConjunctOp>
},
Binary {
lhs: Tk,
operator: Tk,
rhs: Tk,
conjunct: Option<ConjunctOp>
}
}
#[derive(Default,Clone,Debug)]
pub struct TestCaseBuilder {
lhs: Option<Tk>,
operator: Option<Tk>,
rhs: Option<Tk>,
conjunct: Option<ConjunctOp>
}
impl TestCaseBuilder {
pub fn new() -> Self {
Self::default()
}
pub fn is_empty(&self) -> bool {
self.lhs.is_none() &&
self.operator.is_none() &&
self.rhs.is_none() &&
self.conjunct.is_none()
}
pub fn with_lhs(self, lhs: Tk) -> Self {
let Self { lhs: _, operator, rhs, conjunct } = self;
Self { lhs: Some(lhs), operator, rhs, conjunct }
}
pub fn with_rhs(self, rhs: Tk) -> Self {
let Self { lhs, operator, rhs: _, conjunct } = self;
Self { lhs, operator, rhs: Some(rhs), conjunct }
}
pub fn with_operator(self, operator: Tk) -> Self {
let Self { lhs, operator: _, rhs, conjunct } = self;
Self { lhs, operator: Some(operator), rhs, conjunct }
}
pub fn with_conjunction(self, conjunction: ConjunctOp) -> Self {
let Self { lhs, operator, rhs, conjunct: _ } = self;
Self { lhs, operator, rhs, conjunct: Some(conjunction) }
}
pub fn can_build(&self) -> bool {
self.operator.is_some() &&
self.rhs.is_some()
}
pub fn build(self) -> TestCase {
let Self { lhs, operator, rhs, conjunct } = self;
if let Some(lhs) = lhs {
TestCase::Binary {
lhs,
operator: operator.unwrap(),
rhs: rhs.unwrap(),
conjunct
}
} else {
TestCase::Unary {
operator: operator.unwrap(),
operand: rhs.unwrap(),
conjunct
}
}
}
pub fn build_and_take(&mut self) -> TestCase {
if self.lhs.is_some() {
TestCase::Binary {
lhs: self.lhs.take().unwrap(),
operator: self.operator.take().unwrap(),
rhs: self.rhs.take().unwrap(),
conjunct: self.conjunct.take(),
}
} else {
TestCase::Unary {
operator: self.operator.take().unwrap(),
operand: self.rhs.take().unwrap(),
conjunct: self.conjunct.take(),
}
}
}
}
impl FromStr for LoopKind {
type Err = ShErr;
fn from_str(s: &str) -> Result<Self, Self::Err> {
match s {
"while" => Ok(Self::While),
"until" => Ok(Self::Until),
_ => Err(ShErr::simple(ShErrKind::ParseErr, format!("Invalid loop kind: {s}")))
}
}
}
impl Display for LoopKind {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
LoopKind::While => write!(f,"while"),
LoopKind::Until => write!(f,"until")
}
}
}
#[derive(Clone,Debug)]
pub enum AssignKind {
Eq,
PlusEq,
MinusEq,
MultEq,
DivEq,
}
#[derive(Clone,Debug)]
pub enum NdRule {
IfNode { cond_nodes: Vec<CondNode>, else_block: Vec<Node> },
LoopNode { kind: LoopKind, cond_node: CondNode },
ForNode { vars: Vec<Tk>, arr: Vec<Tk>, body: Vec<Node> },
CaseNode { pattern: Tk, case_blocks: Vec<CaseNode> },
Command { assignments: Vec<Node>, argv: Vec<Tk> },
Pipeline { cmds: Vec<Node>, pipe_err: bool },
Conjunction { elements: Vec<ConjunctNode> },
Assignment { kind: AssignKind, var: Tk, val: Tk },
BraceGrp { body: Vec<Node> },
Test { cases: Vec<TestCase> },
FuncDef { name: Tk, body: Box<Node> }
}
#[derive(Debug)]
pub struct ParseStream {
pub tokens: Vec<Tk>,
}
impl ParseStream {
pub fn new(tokens: Vec<Tk>) -> Self {
Self { tokens }
}
fn next_tk_class(&self) -> &TkRule {
if let Some(tk) = self.tokens.first() {
&tk.class
} else {
&TkRule::Null
}
}
fn peek_tk(&self) -> Option<&Tk> {
self.tokens.first()
}
fn next_tk(&mut self) -> Option<Tk> {
if !self.tokens.is_empty() {
if *self.next_tk_class() == TkRule::EOI {
return None
}
Some(self.tokens.remove(0))
} else {
None
}
}
/// Catches a Sep token in cases where separators are optional
///
/// e.g. both `if foo; then bar; fi` and
/// ```bash
/// if foo; then
/// bar
/// fi
/// ```
/// are valid syntax
fn catch_separator(&mut self, node_tks: &mut Vec<Tk>) {
if *self.next_tk_class() == TkRule::Sep {
node_tks.push(self.next_tk().unwrap());
}
}
fn assert_separator(&mut self, node_tks: &mut Vec<Tk>) -> ShResult<()> {
let next_class = self.next_tk_class();
match next_class {
TkRule::EOI |
TkRule::Or |
TkRule::Bg |
TkRule::And |
TkRule::BraceGrpEnd |
TkRule::Pipe => Ok(()),
TkRule::Sep => {
if let Some(tk) = self.next_tk() {
node_tks.push(tk);
}
Ok(())
}
_ => {
Err(
ShErr::simple(ShErrKind::ParseErr, "Expected a semicolon or newline here")
)
}
}
}
fn next_tk_is_some(&self) -> bool {
self.tokens.first().is_some_and(|tk| tk.class != TkRule::EOI)
}
fn check_case_pattern(&self) -> bool {
self.tokens.first().is_some_and(|tk| tk.class == TkRule::CasePattern)
}
fn check_keyword(&self, kw: &str) -> bool {
self.tokens.first().is_some_and(|tk| {
if kw == "in" {
tk.span.as_str() == "in"
} else {
tk.flags.contains(TkFlags::KEYWORD) && tk.span.as_str() == kw
}
})
}
fn check_redir(&self) -> bool {
self.tokens.first().is_some_and(|tk| {
tk.class == TkRule::Redir
})
}
/// Slice off consumed tokens
fn commit(&mut self, num_consumed: usize) {
assert!(num_consumed <= self.tokens.len());
self.tokens = self.tokens[num_consumed..].to_vec();
}
/// This tries to match on different stuff that can appear in a command position
/// Matches shell commands like if-then-fi, pipelines, etc.
/// Ordered from specialized to general, with more generally matchable stuff appearing at the bottom
/// The check_pipelines parameter is used to prevent left-recursion issues in self.parse_pipeln()
fn parse_block(&mut self, check_pipelines: bool) -> ShResult<Option<Node>> {
flog!(DEBUG, self.tokens);
try_match!(self.parse_func_def()?);
try_match!(self.parse_brc_grp(false /* from_func_def */)?);
try_match!(self.parse_case()?);
try_match!(self.parse_loop()?);
try_match!(self.parse_for()?);
try_match!(self.parse_if()?);
try_match!(self.parse_test()?);
if check_pipelines {
try_match!(self.parse_pipeln()?);
} else {
try_match!(self.parse_cmd()?);
}
Ok(None)
}
fn parse_cmd_list(&mut self) -> ShResult<Option<Node>> {
let mut elements = vec![];
let mut node_tks = vec![];
while let Some(block) = self.parse_block(true)? {
node_tks.append(&mut block.tokens.clone());
let conjunct_op = match self.next_tk_class() {
TkRule::And => ConjunctOp::And,
TkRule::Or => ConjunctOp::Or,
_ => ConjunctOp::Null
};
let conjunction = ConjunctNode { cmd: Box::new(block), operator: conjunct_op };
elements.push(conjunction);
if conjunct_op != ConjunctOp::Null {
let Some(tk) = self.next_tk() else {
break
};
node_tks.push(tk);
}
if conjunct_op == ConjunctOp::Null {
break
}
}
if elements.is_empty() {
Ok(None)
} else {
Ok(Some(Node {
class: NdRule::Conjunction { elements },
flags: NdFlags::empty(),
redirs: vec![],
tokens: node_tks
}))
}
}
fn parse_func_def(&mut self) -> ShResult<Option<Node>> {
let mut node_tks: Vec<Tk> = vec![];
let body;
if !is_func_name(self.peek_tk()) {
return Ok(None)
}
let name_tk = self.next_tk().unwrap();
node_tks.push(name_tk.clone());
let name = name_tk;
let Some(brc_grp) = self.parse_brc_grp(true /* from_func_def */)? else {
return Err(parse_err_full(
"Expected a brace group after function name",
&node_tks.get_span().unwrap()
)
)
};
body = Box::new(brc_grp);
let node = Node {
class: NdRule::FuncDef { name, body },
flags: NdFlags::empty(),
redirs: vec![],
tokens: node_tks
};
Ok(Some(node))
}
fn panic_mode(&mut self, node_tks: &mut Vec<Tk>) {
while let Some(tk) = self.next_tk() {
node_tks.push(tk.clone());
if tk.class == TkRule::Sep {
break
}
}
}
fn parse_test(&mut self) -> ShResult<Option<Node>> {
let mut node_tks: Vec<Tk> = vec![];
let mut cases: Vec<TestCase> = vec![];
flog!(INFO, self.check_keyword("[["));
if !self.check_keyword("[[") || !self.next_tk_is_some() {
return Ok(None)
}
node_tks.push(self.next_tk().unwrap());
let mut case_builder = TestCaseBuilder::new();
while let Some(tk) = self.next_tk() {
flog!(DEBUG, case_builder);
flog!(DEBUG, tk.as_str());
node_tks.push(tk.clone());
if tk.as_str() == "]]" {
if case_builder.can_build() {
let case = case_builder.build_and_take();
cases.push(case);
break
} else if cases.is_empty() {
return Err(
parse_err_full("Malformed test call", &node_tks.get_span().unwrap())
)
} else {
break
}
}
if case_builder.is_empty() {
flog!(DEBUG, "case builder is empty");
match tk.as_str() {
_ if TEST_UNARY_OPS.contains(&tk.as_str()) => case_builder = case_builder.with_operator(tk.clone()),
_ => case_builder = case_builder.with_lhs(tk.clone())
}
continue
} else if case_builder.operator.is_some() && case_builder.rhs.is_none() {
flog!(DEBUG, "op is some, rhs is none");
case_builder = case_builder.with_rhs(tk.clone());
continue
} else if case_builder.lhs.is_some() && case_builder.operator.is_none() {
flog!(DEBUG, "lhs is some, op is none");
// we got lhs, then rhs → treat it as operator maybe?
case_builder = case_builder.with_operator(tk.clone());
continue
} else if let TkRule::And | TkRule::Or = tk.class {
flog!(DEBUG, "found conjunction");
flog!(DEBUG, tk.class);
if case_builder.can_build() {
if case_builder.conjunct.is_some() {
return Err(
parse_err_full("Invalid placement for logical operator in test", &node_tks.get_span().unwrap())
)
}
let op = match tk.class {
TkRule::And => ConjunctOp::And,
TkRule::Or => ConjunctOp::Or,
_ => unreachable!()
};
case_builder = case_builder.with_conjunction(op);
let case = case_builder.build_and_take();
cases.push(case);
flog!(DEBUG, case_builder);
continue
} else {
return Err(
parse_err_full("Invalid placement for logical operator in test", &node_tks.get_span().unwrap())
)
}
}
if case_builder.can_build() {
let case = case_builder.build_and_take();
cases.push(case);
}
}
self.catch_separator(&mut node_tks);
let node: Node = Node {
class: NdRule::Test { cases },
flags: NdFlags::empty(),
redirs: vec![],
tokens: node_tks
};
flog!(DEBUG, node);
Ok(Some(node))
}
fn parse_brc_grp(&mut self, from_func_def: bool) -> ShResult<Option<Node>> {
let mut node_tks: Vec<Tk> = vec![];
let mut body: Vec<Node> = vec![];
let mut redirs: Vec<Redir> = vec![];
if *self.next_tk_class() != TkRule::BraceGrpStart {
return Ok(None)
}
node_tks.push(self.next_tk().unwrap());
loop {
if *self.next_tk_class() == TkRule::BraceGrpEnd {
node_tks.push(self.next_tk().unwrap());
break
}
if let Some(node) = self.parse_block(true)? {
node_tks.extend(node.tokens.clone());
body.push(node);
}
if !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected a closing brace for this brace group",
&node_tks.get_span().unwrap()
)
)
}
}
if !from_func_def {
while self.check_redir() {
let tk = self.next_tk().unwrap();
node_tks.push(tk.clone());
let redir_bldr = tk.span.as_str().parse::<RedirBldr>().unwrap();
if redir_bldr.io_mode.is_none() {
let path_tk = self.next_tk();
if path_tk.clone().is_none_or(|tk| tk.class == TkRule::EOI) {
return Err(
ShErr::full(
ShErrKind::ParseErr,
"Expected a filename after this redirection",
tk.span.clone()
)
)
};
let path_tk = path_tk.unwrap();
node_tks.push(path_tk.clone());
let redir_class = redir_bldr.class.unwrap();
let pathbuf = PathBuf::from(path_tk.span.as_str());
let Ok(file) = get_redir_file(redir_class, pathbuf) else {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Error opening file for redirection",
&path_tk.span
)
);
};
let io_mode = IoMode::file(redir_bldr.tgt_fd.unwrap(), file);
let redir_bldr = redir_bldr.with_io_mode(io_mode);
let redir = redir_bldr.build();
redirs.push(redir);
}
}
}
let node = Node {
class: NdRule::BraceGrp { body },
flags: NdFlags::empty(),
redirs,
tokens: node_tks
};
Ok(Some(node))
}
fn parse_case(&mut self) -> ShResult<Option<Node>> {
// Needs a pattern token
// Followed by any number of CaseNodes
let mut node_tks: Vec<Tk> = vec![];
let mut case_blocks: Vec<CaseNode> = vec![];
let redirs: Vec<Redir> = vec![];
if !self.check_keyword("case") || !self.next_tk_is_some() {
return Ok(None)
}
node_tks.push(self.next_tk().unwrap());
let pat_err = parse_err_full(
"Expected a pattern after 'case' keyword", &node_tks.get_span().unwrap()
)
.with_note(
Note::new("Patterns can be raw text, or anything that gets substituted with raw text")
.with_sub_notes(vec![
"This includes variables like '$foo' or command substitutions like '$(echo foo)'"
])
);
let Some(pat_tk) = self.next_tk() else {
self.panic_mode(&mut node_tks);
return Err(pat_err);
};
if pat_tk.span.as_str() == "in" {
return Err(pat_err)
}
let pattern: Tk = pat_tk;
node_tks.push(pattern.clone());
if !self.check_keyword("in") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("Expected 'in' after case variable name", &node_tks.get_span().unwrap()));
}
node_tks.push(self.next_tk().unwrap());
self.catch_separator(&mut node_tks);
loop {
if !self.check_case_pattern() || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("Expected a case pattern here", &node_tks.get_span().unwrap()));
}
let case_pat_tk = self.next_tk().unwrap();
node_tks.push(case_pat_tk.clone());
self.catch_separator(&mut node_tks);
let mut nodes = vec![];
while let Some(node) = self.parse_block(true /* check_pipelines */)? {
node_tks.extend(node.tokens.clone());
let sep = node.tokens.last().unwrap();
if sep.has_double_semi() {
nodes.push(node);
break
} else {
nodes.push(node);
}
}
let case_node = CaseNode { pattern: case_pat_tk, body: nodes };
case_blocks.push(case_node);
if self.check_keyword("esac") {
node_tks.push(self.next_tk().unwrap());
self.assert_separator(&mut node_tks)?;
break
}
if !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("Expected 'esac' after case block", &node_tks.get_span().unwrap()));
}
}
let node = Node {
class: NdRule::CaseNode { pattern, case_blocks },
flags: NdFlags::empty(),
redirs,
tokens: node_tks
};
Ok(Some(node))
}
fn parse_if(&mut self) -> ShResult<Option<Node>> {
// Needs at last one 'if-then',
// Any number of 'elif-then',
// Zero or one 'else'
let mut node_tks: Vec<Tk> = vec![];
let mut cond_nodes: Vec<CondNode> = vec![];
let mut else_block: Vec<Node> = vec![];
let mut redirs: Vec<Redir> = vec![];
if !self.check_keyword("if") || !self.next_tk_is_some() {
return Ok(None)
}
node_tks.push(self.next_tk().unwrap());
loop {
let prefix_keywrd = if cond_nodes.is_empty() {
"if"
} else {
"elif"
};
let Some(cond) = self.parse_block(true)? else {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
&format!("Expected an expression after '{prefix_keywrd}'"),
&node_tks.get_span().unwrap()
));
};
node_tks.extend(cond.tokens.clone());
if !self.check_keyword("then") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
&format!("Expected 'then' after '{prefix_keywrd}' condition"),
&node_tks.get_span().unwrap()
));
}
node_tks.push(self.next_tk().unwrap());
self.catch_separator(&mut node_tks);
let mut body_blocks = vec![];
while let Some(body_block) = self.parse_block(true)? {
node_tks.extend(body_block.tokens.clone());
body_blocks.push(body_block);
}
if body_blocks.is_empty() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected an expression after 'then'",
&node_tks.get_span().unwrap()
));
};
let cond_node = CondNode { cond: Box::new(cond), body: body_blocks };
cond_nodes.push(cond_node);
if !self.check_keyword("elif") || !self.next_tk_is_some() {
break
} else {
node_tks.push(self.next_tk().unwrap());
self.catch_separator(&mut node_tks);
}
}
if self.check_keyword("else") {
node_tks.push(self.next_tk().unwrap());
self.catch_separator(&mut node_tks);
while let Some(block) = self.parse_block(true)? {
else_block.push(block)
}
if else_block.is_empty() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected an expression after 'else'",
&node_tks.get_span().unwrap()
));
}
}
if !self.check_keyword("fi") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected 'fi' after if statement",
&node_tks.get_span().unwrap()
));
}
node_tks.push(self.next_tk().unwrap());
while self.check_redir() {
let tk = self.next_tk().unwrap();
node_tks.push(tk.clone());
let redir_bldr = tk.span.as_str().parse::<RedirBldr>().unwrap();
if redir_bldr.io_mode.is_none() {
let path_tk = self.next_tk();
if path_tk.clone().is_none_or(|tk| tk.class == TkRule::EOI) {
return Err(
ShErr::full(
ShErrKind::ParseErr,
"Expected a filename after this redirection",
tk.span.clone()
)
)
};
let path_tk = path_tk.unwrap();
node_tks.push(path_tk.clone());
let redir_class = redir_bldr.class.unwrap();
let pathbuf = PathBuf::from(path_tk.span.as_str());
let Ok(file) = get_redir_file(redir_class, pathbuf) else {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Error opening file for redirection",
&path_tk.span
));
};
let io_mode = IoMode::file(redir_bldr.tgt_fd.unwrap(), file);
let redir_bldr = redir_bldr.with_io_mode(io_mode);
let redir = redir_bldr.build();
redirs.push(redir);
}
}
self.assert_separator(&mut node_tks)?;
let node = Node {
class: NdRule::IfNode { cond_nodes, else_block },
flags: NdFlags::empty(),
redirs,
tokens: node_tks
};
Ok(Some(node))
}
fn parse_for(&mut self) -> ShResult<Option<Node>> {
let mut node_tks: Vec<Tk> = vec![];
let mut vars: Vec<Tk> = vec![];
let mut arr: Vec<Tk> = vec![];
let mut body: Vec<Node> = vec![];
let mut redirs: Vec<Redir> = vec![];
if !self.check_keyword("for") || !self.next_tk_is_some() {
return Ok(None)
}
node_tks.push(self.next_tk().unwrap());
while let Some(tk) = self.next_tk() {
node_tks.push(tk.clone());
if tk.as_str() == "in" {
break
} else {
vars.push(tk.clone());
}
}
while let Some(tk) = self.next_tk() {
node_tks.push(tk.clone());
if tk.class == TkRule::Sep {
break
} else {
arr.push(tk.clone());
}
}
if vars.is_empty() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("This for loop is missing a variable", &node_tks.get_span().unwrap()))
}
if arr.is_empty() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("This for loop is missing an array", &node_tks.get_span().unwrap()))
}
if !self.check_keyword("do") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("Missing a 'do' for this for loop", &node_tks.get_span().unwrap()))
}
node_tks.push(self.next_tk().unwrap());
self.catch_separator(&mut node_tks);
while let Some(node) = self.parse_block(true)? {
body.push(node)
}
if !self.check_keyword("done") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full("Missing a 'done' after this for loop", &node_tks.get_span().unwrap()))
}
node_tks.push(self.next_tk().unwrap());
while self.check_redir() {
let tk = self.next_tk().unwrap();
node_tks.push(tk.clone());
let redir_bldr = tk.span.as_str().parse::<RedirBldr>().unwrap();
if redir_bldr.io_mode.is_none() {
let path_tk = self.next_tk();
if path_tk.clone().is_none_or(|tk| tk.class == TkRule::EOI) {
return Err(
ShErr::full(
ShErrKind::ParseErr,
"Expected a filename after this redirection",
tk.span.clone()
)
)
};
let path_tk = path_tk.unwrap();
node_tks.push(path_tk.clone());
let redir_class = redir_bldr.class.unwrap();
let pathbuf = PathBuf::from(path_tk.span.as_str());
let Ok(file) = get_redir_file(redir_class, pathbuf) else {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Error opening file for redirection",
&path_tk.span
));
};
let io_mode = IoMode::file(redir_bldr.tgt_fd.unwrap(), file);
let redir_bldr = redir_bldr.with_io_mode(io_mode);
let redir = redir_bldr.build();
redirs.push(redir);
}
}
let node = Node {
class: NdRule::ForNode { vars, arr, body },
flags: NdFlags::empty(),
redirs,
tokens: node_tks
};
Ok(Some(node))
}
fn parse_loop(&mut self) -> ShResult<Option<Node>> {
// Requires a single CondNode and a LoopKind
let cond_node: CondNode;
let mut node_tks = vec![];
if (!self.check_keyword("while") && !self.check_keyword("until")) || !self.next_tk_is_some() {
return Ok(None)
}
let loop_tk = self.next_tk().unwrap();
let loop_kind: LoopKind = loop_tk.span
.as_str()
.parse() // LoopKind implements FromStr
.unwrap();
node_tks.push(loop_tk);
self.catch_separator(&mut node_tks);
flog!(DEBUG, node_tks);
let Some(cond) = self.parse_block(true)? else {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
&format!("Expected an expression after '{loop_kind}'"), // It also implements Display
&node_tks.get_span().unwrap()
))
};
node_tks.extend(cond.tokens.clone());
if !self.check_keyword("do") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected 'do' after loop condition",
&node_tks.get_span().unwrap()
))
}
node_tks.push(self.next_tk().unwrap());
self.catch_separator(&mut node_tks);
let mut body = vec![];
while let Some(block) = self.parse_block(true)? {
node_tks.extend(block.tokens.clone());
body.push(block);
}
if body.is_empty() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected an expression after 'do'",
&node_tks.get_span().unwrap()
))
};
if !self.check_keyword("done") || !self.next_tk_is_some() {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Expected 'done' after loop body",
&node_tks.get_span().unwrap()
))
}
node_tks.push(self.next_tk().unwrap());
self.assert_separator(&mut node_tks)?;
cond_node = CondNode { cond: Box::new(cond), body };
let loop_node = Node {
class: NdRule::LoopNode { kind: loop_kind, cond_node },
flags: NdFlags::empty(),
redirs: vec![],
tokens: node_tks
};
Ok(Some(loop_node))
}
fn parse_pipeln(&mut self) -> ShResult<Option<Node>> {
let mut cmds = vec![];
let mut node_tks = vec![];
while let Some(cmd) = self.parse_block(false)? {
let is_punctuated = node_is_punctuated(&cmd.tokens);
node_tks.append(&mut cmd.tokens.clone());
cmds.push(cmd);
if *self.next_tk_class() != TkRule::Pipe || is_punctuated {
break
} else if let Some(pipe) = self.next_tk() {
node_tks.push(pipe)
} else {
break
}
}
if cmds.is_empty() {
Ok(None)
} else {
Ok(Some(Node {
// TODO: implement pipe_err support
class: NdRule::Pipeline { cmds, pipe_err: false },
flags: NdFlags::empty(),
redirs: vec![],
tokens: node_tks
}))
}
}
fn parse_cmd(&mut self) -> ShResult<Option<Node>> {
let tk_slice = self.tokens.clone();
let mut tk_iter = tk_slice.iter();
let mut node_tks = vec![];
let mut redirs = vec![];
let mut argv = vec![];
let mut assignments = vec![];
while let Some(prefix_tk) = tk_iter.next() {
if let TkRule::CasePattern = prefix_tk.class {
return Err(parse_err_full("Found case pattern in command", &prefix_tk.span))
}
let is_cmd = prefix_tk.flags.contains(TkFlags::IS_CMD);
let is_assignment = prefix_tk.flags.contains(TkFlags::ASSIGN);
let is_keyword = prefix_tk.flags.contains(TkFlags::KEYWORD);
if is_cmd {
node_tks.push(prefix_tk.clone());
argv.push(prefix_tk.clone());
break
} else if is_assignment {
let Some(assign) = self.parse_assignment(prefix_tk) else {
break
};
node_tks.push(prefix_tk.clone());
assignments.push(assign)
} else if is_keyword {
return Ok(None)
}
}
flog!(DEBUG, argv);
if argv.is_empty() && assignments.is_empty() {
return Ok(None)
}
while let Some(tk) = tk_iter.next() {
match tk.class {
TkRule::EOI |
TkRule::Pipe |
TkRule::And |
TkRule::BraceGrpEnd |
TkRule::Or => {
break
}
TkRule::Sep => {
node_tks.push(tk.clone());
break
}
TkRule::Str => {
argv.push(tk.clone());
node_tks.push(tk.clone());
}
TkRule::Redir => {
node_tks.push(tk.clone());
let redir_bldr = tk.span.as_str().parse::<RedirBldr>().unwrap();
if redir_bldr.io_mode.is_none() {
let path_tk = tk_iter.next();
if path_tk.is_none_or(|tk| tk.class == TkRule::EOI) {
return Err(
ShErr::full(
ShErrKind::ParseErr,
"Expected a filename after this redirection",
tk.span.clone()
)
)
};
let path_tk = path_tk.unwrap();
node_tks.push(path_tk.clone());
let redir_class = redir_bldr.class.unwrap();
let pathbuf = PathBuf::from(path_tk.span.as_str());
let Ok(file) = get_redir_file(redir_class, pathbuf) else {
self.panic_mode(&mut node_tks);
return Err(parse_err_full(
"Error opening file for redirection",
&path_tk.span
));
};
let io_mode = IoMode::file(redir_bldr.tgt_fd.unwrap(), file);
let redir_bldr = redir_bldr.with_io_mode(io_mode);
let redir = redir_bldr.build();
redirs.push(redir);
}
}
_ => unimplemented!("Unexpected token rule `{:?}` in parse_cmd()",tk.class)
}
}
self.commit(node_tks.len());
Ok(Some(Node {
class: NdRule::Command { assignments, argv },
tokens: node_tks,
flags: NdFlags::empty(),
redirs,
}))
}
fn parse_assignment(&self, token: &Tk) -> Option<Node> {
let mut chars = token.span.as_str().chars();
let mut var_name = String::new();
let mut name_range = token.span.start..token.span.start;
let mut var_val = String::new();
let mut val_range = token.span.end..token.span.end;
let mut assign_kind = None;
let mut pos = token.span.start;
while let Some(ch) = chars.next() {
if assign_kind.is_some() {
match ch {
'\\' => {
pos += ch.len_utf8();
var_val.push(ch);
if let Some(esc_ch) = chars.next() {
pos += esc_ch.len_utf8();
var_val.push(esc_ch);
}
}
_ => {
pos += ch.len_utf8();
var_val.push(ch);
}
}
} else {
match ch {
'=' => {
name_range.end = pos;
pos += ch.len_utf8();
val_range.start = pos;
assign_kind = Some(AssignKind::Eq);
}
'-' => {
name_range.end = pos;
pos += ch.len_utf8();
let Some('=') = chars.next() else {
return None
};
pos += '='.len_utf8();
val_range.start = pos;
assign_kind = Some(AssignKind::MinusEq);
}
'+' => {
name_range.end = pos;
pos += ch.len_utf8();
let Some('=') = chars.next() else {
return None
};
pos += '='.len_utf8();
val_range.start = pos;
assign_kind = Some(AssignKind::PlusEq);
}
'/' => {
name_range.end = pos;
pos += ch.len_utf8();
let Some('=') = chars.next() else {
return None
};
pos += '='.len_utf8();
val_range.start = pos;
assign_kind = Some(AssignKind::DivEq);
}
'*' => {
name_range.end = pos;
pos += ch.len_utf8();
let Some('=') = chars.next() else {
return None
};
pos += '='.len_utf8();
val_range.start = pos;
assign_kind = Some(AssignKind::MultEq);
}
'\\' => {
pos += ch.len_utf8();
var_name.push(ch);
if let Some(esc_ch) = chars.next() {
pos += esc_ch.len_utf8();
var_name.push(esc_ch);
}
}
_ => {
pos += ch.len_utf8();
var_name.push(ch)
}
}
}
}
if assign_kind.is_none() || var_name.is_empty() {
None
} else {
let var = Tk::new(TkRule::Str, Span::new(name_range, token.source()));
let val = Tk::new(TkRule::Str, Span::new(val_range, token.source()));
Some(Node {
class: NdRule::Assignment { kind: assign_kind.unwrap(), var, val },
tokens: vec![token.clone()],
flags: NdFlags::empty(),
redirs: vec![]
})
}
}
}
impl Iterator for ParseStream {
type Item = ShResult<Node>;
fn next(&mut self) -> Option<Self::Item> {
// Empty token vector or only SOI/EOI tokens, nothing to do
if self.tokens.is_empty() || self.tokens.len() == 1 {
return None
}
while let Some(tk) = self.tokens.first() {
if let TkRule::EOI = tk.class {
return None
}
if let TkRule::SOI | TkRule::Sep = tk.class {
self.next_tk();
} else {
break
}
}
let result = self.parse_cmd_list();
match result {
Ok(Some(node)) => {
Some(Ok(node))
}
Ok(None) => None,
Err(e) => {
Some(Err(e))
}
}
}
}
fn node_is_punctuated(tokens: &[Tk]) -> bool {
tokens.last().is_some_and(|tk| {
matches!(tk.class, TkRule::Sep)
})
}
fn get_redir_file(class: RedirType, path: PathBuf) -> ShResult<File> {
let result = match class {
RedirType::Input => {
OpenOptions::new()
.read(true)
.open(Path::new(&path))
}
RedirType::Output => {
OpenOptions::new()
.write(true)
.create(true)
.truncate(true)
.open(Path::new(&path))
}
RedirType::Append => {
OpenOptions::new()
.create(true)
.append(true)
.open(Path::new(&path))
}
_ => unimplemented!()
};
Ok(result?)
}
fn parse_err_full(reason: &str, blame: &Span) -> ShErr {
ShErr::full(
ShErrKind::ParseErr,
reason,
blame.clone()
)
}
fn is_func_name(tk: Option<&Tk>) -> bool {
tk.is_some_and(|tk| {
tk.flags.contains(TkFlags::KEYWORD) &&
(tk.span.as_str().ends_with("()") && !tk.span.as_str().ends_with("\\()"))
})
}
/// Perform an operation on the child nodes of a given node
///
/// # Parameters
/// node: A mutable reference to a node to be operated on
/// filter: A closure or function which checks an attribute of a child node and returns a boolean
/// operation: The closure or function to apply to a child node which matches on the filter
///
/// Very useful for testing, i.e. needing to extract specific types of nodes from the AST to inspect values
pub fn node_operation<F1,F2>(node: &mut Node, filter: &F1, operation: &mut F2)
where
F1: Fn(&Node) -> bool,
F2: FnMut(&mut Node)
{
let check_node = |node: &mut Node, filter: &F1, operation: &mut F2| {
if filter(node) {
operation(node);
} else {
node_operation::<F1,F2>(node, filter, operation);
}
};
if filter(node) {
operation(node);
}
match node.class {
NdRule::IfNode { ref mut cond_nodes, ref mut else_block } => {
for node in cond_nodes {
let CondNode { cond, body } = node;
check_node(cond,filter,operation);
for body_node in body {
check_node(body_node,filter,operation);
}
}
for else_node in else_block {
check_node(else_node,filter,operation);
}
}
NdRule::LoopNode { kind: _, ref mut cond_node } => {
let CondNode { cond, body } = cond_node;
check_node(cond,filter,operation);
for body_node in body {
check_node(body_node,filter,operation);
}
}
NdRule::ForNode { vars: _, arr: _, ref mut body } => {
for body_node in body {
check_node(body_node,filter,operation);
}
}
NdRule::CaseNode { pattern: _, ref mut case_blocks } => {
for block in case_blocks {
let CaseNode { pattern: _, body } = block;
for body_node in body {
check_node(body_node,filter,operation);
}
}
}
NdRule::Command { ref mut assignments, argv: _ } => {
for assign_node in assignments {
check_node(assign_node,filter,operation);
}
}
NdRule::Pipeline { ref mut cmds, pipe_err: _ } => {
for cmd_node in cmds {
check_node(cmd_node,filter,operation);
}
}
NdRule::Conjunction { ref mut elements } => {
for node in elements.iter_mut() {
let ConjunctNode { cmd, operator: _ } = node;
check_node(cmd,filter,operation);
}
}
NdRule::Assignment { kind: _, var: _, val: _ } => (), // No nodes to check
NdRule::BraceGrp { ref mut body } => {
for body_node in body {
check_node(body_node,filter,operation);
}
}
NdRule::FuncDef { name: _, ref mut body } => {
check_node(body,filter,operation)
}
NdRule::Test { cases: _ } => (),
}
}
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