forked from fish-shell/fish-shell
/
tokenizer.rs
1297 lines (1216 loc) · 47.6 KB
/
tokenizer.rs
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//! A specialized tokenizer for tokenizing the fish language. In the future, the tokenizer should be
//! extended to support marks, tokenizing multiple strings and disposing of unused string segments.
use crate::common::valid_var_name_char;
use crate::future_feature_flags::{feature_test, FeatureFlag};
use crate::parse_constants::SOURCE_OFFSET_INVALID;
use crate::redirection::RedirectionMode;
use crate::wchar::prelude::*;
use libc::{STDIN_FILENO, STDOUT_FILENO};
use nix::fcntl::OFlag;
use std::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, Not};
use std::os::fd::RawFd;
/// Token types. XXX Why this isn't ParseTokenType, I'm not really sure.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum TokenType {
/// Error reading token
error,
/// String token
string,
/// Pipe token
pipe,
/// && token
andand,
/// || token
oror,
/// End token (semicolon or newline, not literal end)
end,
/// redirection token
redirect,
/// send job to bg token
background,
/// comment token
comment,
}
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum TokenizerError {
none,
unterminated_quote,
unterminated_subshell,
unterminated_slice,
unterminated_escape,
invalid_redirect,
invalid_pipe,
invalid_pipe_ampersand,
closing_unopened_subshell,
illegal_slice,
closing_unopened_brace,
unterminated_brace,
expected_pclose_found_bclose,
expected_bclose_found_pclose,
}
pub struct Tok {
// Offset of the token.
pub offset: u32,
// Length of the token.
pub length: u32,
// If an error, this is the offset of the error within the token. A value of 0 means it occurred
// at 'offset'.
pub error_offset_within_token: u32,
pub error_length: u32,
// If an error, this is the error code.
pub error: TokenizerError,
// The type of the token.
pub type_: TokenType,
}
// TODO static_assert(sizeof(Tok) <= 32, "Tok expected to be 32 bytes or less");
/// Struct wrapping up a parsed pipe or redirection.
pub struct PipeOrRedir {
// The redirected fd, or -1 on overflow.
// In the common case of a pipe, this is 1 (STDOUT_FILENO).
// For example, in the case of "3>&1" this will be 3.
pub fd: i32,
// Whether we are a pipe (true) or redirection (false).
pub is_pipe: bool,
// The redirection mode if the type is redirect.
// Ignored for pipes.
pub mode: RedirectionMode,
// Whether, in addition to this redirection, stderr should also be dup'd to stdout
// For example &| or &>
pub stderr_merge: bool,
// Number of characters consumed when parsing the string.
pub consumed: usize,
}
pub enum MoveWordStyle {
/// stop at punctuation
Punctuation,
/// stops at path components
PathComponents,
/// stops at whitespace
Whitespace,
}
/// Our state machine that implements "one word" movement or erasure.
pub struct MoveWordStateMachine {
state: u8,
style: MoveWordStyle,
}
#[derive(Clone, Copy)]
pub struct TokFlags(pub u8);
impl BitAnd for TokFlags {
type Output = bool;
fn bitand(self, rhs: Self) -> Self::Output {
(self.0 & rhs.0) != 0
}
}
impl BitOr for TokFlags {
type Output = Self;
fn bitor(self, rhs: Self) -> Self::Output {
Self(self.0 | rhs.0)
}
}
impl BitOrAssign for TokFlags {
fn bitor_assign(&mut self, rhs: Self) {
self.0 |= rhs.0
}
}
/// Flag telling the tokenizer to accept incomplete parameters, i.e. parameters with mismatching
/// parenthesis, etc. This is useful for tab-completion.
pub const TOK_ACCEPT_UNFINISHED: TokFlags = TokFlags(1);
/// Flag telling the tokenizer not to remove comments. Useful for syntax highlighting.
pub const TOK_SHOW_COMMENTS: TokFlags = TokFlags(2);
/// Ordinarily, the tokenizer ignores newlines following a newline, or a semicolon. This flag tells
/// the tokenizer to return each of them as a separate END.
pub const TOK_SHOW_BLANK_LINES: TokFlags = TokFlags(4);
/// Make an effort to continue after an error.
pub const TOK_CONTINUE_AFTER_ERROR: TokFlags = TokFlags(8);
impl From<TokenizerError> for &'static wstr {
fn from(err: TokenizerError) -> Self {
match err {
TokenizerError::none => L!(""),
TokenizerError::unterminated_quote => {
wgettext!("Unexpected end of string, quotes are not balanced")
}
TokenizerError::unterminated_subshell => {
wgettext!("Unexpected end of string, expecting ')'")
}
TokenizerError::unterminated_slice => {
wgettext!("Unexpected end of string, square brackets do not match")
}
TokenizerError::unterminated_escape => {
wgettext!("Unexpected end of string, incomplete escape sequence")
}
TokenizerError::invalid_redirect => {
wgettext!("Invalid input/output redirection")
}
TokenizerError::invalid_pipe => {
wgettext!("Cannot use stdin (fd 0) as pipe output")
}
TokenizerError::invalid_pipe_ampersand => {
wgettext!("|& is not valid. In fish, use &| to pipe both stdout and stderr.")
}
TokenizerError::closing_unopened_subshell => {
wgettext!("Unexpected ')' for unopened parenthesis")
}
TokenizerError::illegal_slice => {
wgettext!("Unexpected '[' at this location")
}
TokenizerError::closing_unopened_brace => {
wgettext!("Unexpected '}' for unopened brace expansion")
}
TokenizerError::unterminated_brace => {
wgettext!("Unexpected end of string, incomplete parameter expansion")
}
TokenizerError::expected_pclose_found_bclose => {
wgettext!("Unexpected '}' found, expecting ')'")
}
TokenizerError::expected_bclose_found_pclose => {
wgettext!("Unexpected ')' found, expecting '}'")
}
}
}
}
impl printf_compat::args::ToArg<'static> for TokenizerError {
fn to_arg(self) -> printf_compat::args::Arg<'static> {
printf_compat::args::Arg::Str(self.into())
}
}
impl Tok {
fn new(r#type: TokenType) -> Tok {
Tok {
offset: 0,
length: 0,
error_offset_within_token: SOURCE_OFFSET_INVALID.try_into().unwrap(),
error_length: 0,
error: TokenizerError::none,
type_: r#type,
}
}
pub fn location_in_or_at_end_of_source_range(self: &Tok, loc: usize) -> bool {
let loc = loc as u32;
self.offset <= loc && loc - self.offset <= self.length
}
pub fn get_source<'a, 'b>(self: &'a Tok, str: &'b wstr) -> &'b wstr {
&str[self.offset as usize..(self.offset + self.length) as usize]
}
pub fn set_offset(&mut self, value: usize) {
self.offset = value.try_into().unwrap();
}
pub fn offset(&self) -> usize {
self.offset.try_into().unwrap()
}
pub fn length(&self) -> usize {
self.length.try_into().unwrap()
}
pub fn set_length(&mut self, value: usize) {
self.length = value.try_into().unwrap();
}
pub fn end(&self) -> usize {
self.offset() + self.length()
}
pub fn set_error_offset_within_token(&mut self, value: usize) {
self.error_offset_within_token = value.try_into().unwrap();
}
pub fn error_offset_within_token(&self) -> usize {
self.error_offset_within_token.try_into().unwrap()
}
pub fn error_length(&self) -> usize {
self.error_length.try_into().unwrap()
}
pub fn set_error_length(&mut self, value: usize) {
self.error_length = value.try_into().unwrap();
}
}
/// The tokenizer struct.
pub struct Tokenizer {
/// A pointer into the original string, showing where the next token begins.
token_cursor: usize,
/// The start of the original string.
start: WString, // TODO Avoid copying once we drop the FFI.
/// Whether we have additional tokens.
has_next: bool,
/// Whether incomplete tokens are accepted.
accept_unfinished: bool,
/// Whether comments should be returned.
show_comments: bool,
/// Whether all blank lines are returned.
show_blank_lines: bool,
/// Whether to attempt to continue after an error.
continue_after_error: bool,
/// Whether to continue the previous line after the comment.
continue_line_after_comment: bool,
}
impl Tokenizer {
/// Constructor for a tokenizer. b is the string that is to be tokenized. It is not copied, and
/// should not be freed by the caller until after the tokenizer is destroyed.
///
/// \param start The string to tokenize
/// \param flags Flags to the tokenizer. Setting TOK_ACCEPT_UNFINISHED will cause the tokenizer
/// to accept incomplete tokens, such as a subshell without a closing parenthesis, as a valid
/// token. Setting TOK_SHOW_COMMENTS will return comments as tokens
pub fn new(start: &wstr, flags: TokFlags) -> Self {
Tokenizer {
token_cursor: 0,
start: start.to_owned(),
has_next: true,
accept_unfinished: flags & TOK_ACCEPT_UNFINISHED,
show_comments: flags & TOK_SHOW_COMMENTS,
show_blank_lines: flags & TOK_SHOW_BLANK_LINES,
continue_after_error: flags & TOK_CONTINUE_AFTER_ERROR,
continue_line_after_comment: false,
}
}
}
impl Iterator for Tokenizer {
type Item = Tok;
fn next(&mut self) -> Option<Self::Item> {
if !self.has_next {
return None;
}
// Consume non-newline whitespace. If we get an escaped newline, mark it and continue past
// it.
loop {
let i = self.token_cursor;
if self.start.get(i..i + 2) == Some(L!("\\\n")) {
self.token_cursor += 2;
self.continue_line_after_comment = true;
} else if i < self.start.len() && iswspace_not_nl(self.start.char_at(i)) {
self.token_cursor += 1;
} else {
break;
}
}
while self.start.char_at(self.token_cursor) == '#' {
// We have a comment, walk over the comment.
let comment_start = self.token_cursor;
self.token_cursor = comment_end(&self.start, self.token_cursor);
let comment_len = self.token_cursor - comment_start;
// If we are going to continue after the comment, skip any trailing newline.
if self.start.as_char_slice().get(self.token_cursor) == Some(&'\n')
&& self.continue_line_after_comment
{
self.token_cursor += 1;
}
// Maybe return the comment.
if self.show_comments {
let mut result = Tok::new(TokenType::comment);
result.offset = comment_start as u32;
result.length = comment_len as u32;
return Some(result);
}
while self.token_cursor < self.start.len()
&& iswspace_not_nl(self.start.char_at(self.token_cursor))
{
self.token_cursor += 1;
}
}
// We made it past the comments and ate any trailing newlines we wanted to ignore.
self.continue_line_after_comment = false;
let start_pos = self.token_cursor;
let this_char = self.start.char_at(self.token_cursor);
let next_char = self
.start
.as_char_slice()
.get(self.token_cursor + 1)
.copied();
let buff = &self.start[self.token_cursor..];
match this_char {
'\0'=> {
self.has_next = false;
None
}
'\r'| // carriage-return
'\n'| // newline
';'=> {
let mut result = Tok::new(TokenType::end);
result.offset = start_pos as u32;
result.length = 1;
self.token_cursor+=1;
// Hack: when we get a newline, swallow as many as we can. This compresses multiple
// subsequent newlines into a single one.
if !self.show_blank_lines {
while self.token_cursor < self.start.len() {
let c = self.start.char_at(self.token_cursor);
if c != '\n' && c != '\r' && c != ' ' && c != '\t' {
break
}
self.token_cursor+=1;
}
}
Some(result)
}
'&'=> {
if next_char == Some('&') {
// && is and.
let mut result = Tok::new(TokenType::andand);
result.offset = start_pos as u32;
result.length = 2;
self.token_cursor += 2;
Some(result)
} else if next_char == Some('>') || next_char == Some('|') {
// &> and &| redirect both stdout and stderr.
let redir = PipeOrRedir::try_from(buff).
expect("Should always succeed to parse a &> or &| redirection");
let mut result = Tok::new(redir.token_type());
result.offset = start_pos as u32;
result.length = redir.consumed as u32;
self.token_cursor += redir.consumed;
Some(result)
} else {
let mut result = Tok::new(TokenType::background);
result.offset = start_pos as u32;
result.length = 1;
self.token_cursor+=1;
Some(result)
}
}
'|'=> {
if next_char == Some('|') {
// || is or.
let mut result=Tok::new(TokenType::oror);
result.offset = start_pos as u32;
result.length = 2;
self.token_cursor += 2;
Some(result)
} else if next_char == Some('&') {
// |& is a bashism; in fish it's &|.
Some(self.call_error(TokenizerError::invalid_pipe_ampersand,
self.token_cursor, self.token_cursor, Some(2), 2))
} else {
let pipe = PipeOrRedir::try_from(buff).
expect("Should always succeed to parse a | pipe");
let mut result = Tok::new(pipe.token_type());
result.offset = start_pos as u32;
result.length = pipe.consumed as u32;
self.token_cursor += pipe.consumed;
Some(result)
}
}
'>'| '<' => {
// There's some duplication with the code in the default case below. The key
// difference here is that we must never parse these as a string; a failed
// redirection is an error!
match PipeOrRedir::try_from(buff) {
Ok(redir_or_pipe) => {
if redir_or_pipe.fd < 0 {
Some(self.call_error(TokenizerError::invalid_redirect, self.token_cursor,
self.token_cursor,
Some(redir_or_pipe.consumed),
redir_or_pipe.consumed))
} else {
let mut result = Tok::new(redir_or_pipe.token_type());
result.offset = start_pos as u32;
result.length = redir_or_pipe.consumed as u32;
self.token_cursor += redir_or_pipe.consumed;
Some(result)
}
}
Err(()) => Some(self.call_error(TokenizerError::invalid_redirect, self.token_cursor,
self.token_cursor,
Some(0),
0))
}
}
_ => {
// Maybe a redirection like '2>&1', maybe a pipe like 2>|, maybe just a string.
let error_location = self.token_cursor;
let redir_or_pipe = if this_char.is_ascii_digit() {
PipeOrRedir::try_from(buff).ok()
} else {
None
};
match redir_or_pipe {
Some(redir_or_pipe) => {
// It looks like a redirection or a pipe. But we don't support piping fd 0. Note
// tSome(hat fd 0 may be -1, indicating overflow; but we don't treat that as a
// tokenizer error.
if redir_or_pipe.is_pipe && redir_or_pipe.fd == 0 {
Some(self.call_error(TokenizerError::invalid_pipe, error_location,
error_location, Some(redir_or_pipe.consumed),
redir_or_pipe.consumed))
}
else {
let mut result = Tok::new(redir_or_pipe.token_type());
result.offset = start_pos as u32;
result.length = redir_or_pipe.consumed as u32;
self.token_cursor += redir_or_pipe.consumed;
Some(result)
}
}
None => {
// Not a redirection or pipe, so just a string.
Some(self.read_string())
}
}
}
}
}
}
/// Test if a character is whitespace. Differs from iswspace in that it does not consider a
/// newline to be whitespace.
fn iswspace_not_nl(c: char) -> bool {
match c {
' ' | '\t' | '\r' => true,
'\n' => false,
_ => c.is_whitespace(),
}
}
impl Tokenizer {
/// Returns the text of a token, as a string.
pub fn text_of(&self, tok: &Tok) -> &wstr {
tok.get_source(&self.start)
}
/// Return an error token and mark that we no longer have a next token.
fn call_error(
&mut self,
error_type: TokenizerError,
token_start: usize,
error_loc: usize,
token_length: Option<usize>,
error_len: usize,
) -> Tok {
assert!(
error_type != TokenizerError::none,
"TokenizerError::none passed to call_error"
);
assert!(error_loc >= token_start, "Invalid error location");
assert!(self.token_cursor >= token_start, "Invalid buff location");
// If continue_after_error is set and we have a real token length, then skip past it.
// Otherwise give up.
match token_length {
Some(token_length) if self.continue_after_error => {
assert!(
self.token_cursor < error_loc + token_length,
"Unable to continue past error"
);
self.token_cursor = error_loc + token_length;
}
_ => self.has_next = false,
}
Tok {
offset: token_start as u32,
length: token_length.unwrap_or(self.token_cursor - token_start) as u32,
error_offset_within_token: (error_loc - token_start) as u32,
error_length: error_len as u32,
error: error_type,
type_: TokenType::error,
}
}
}
impl Tokenizer {
/// Read the next token as a string.
fn read_string(&mut self) -> Tok {
let mut mode = TOK_MODE_REGULAR_TEXT;
let mut paran_offsets = vec![];
let mut brace_offsets = vec![];
let mut expecting = vec![];
let mut quoted_cmdsubs = vec![];
let mut slice_offset = 0;
let buff_start = self.token_cursor;
let mut is_token_begin = true;
fn process_opening_quote(
this: &mut Tokenizer,
quoted_cmdsubs: &mut Vec<usize>,
paran_offsets: &Vec<usize>,
quote: char,
) -> Result<(), usize> {
if let Some(end) = quote_end(&this.start, this.token_cursor, quote) {
if this.start.char_at(end) == '$' {
quoted_cmdsubs.push(paran_offsets.len());
}
this.token_cursor = end;
Ok(())
} else {
let error_loc = this.token_cursor;
this.token_cursor = this.start.len();
Err(error_loc)
}
}
while self.token_cursor != self.start.len() {
let c = self.start.char_at(self.token_cursor);
// Make sure this character isn't being escaped before anything else
if mode & TOK_MODE_CHAR_ESCAPE {
mode &= !TOK_MODE_CHAR_ESCAPE;
// and do nothing more
} else if myal(c) {
// Early exit optimization in case the character is just a letter,
// which has no special meaning to the tokenizer, i.e. the same mode continues.
}
// Now proceed with the evaluation of the token, first checking to see if the token
// has been explicitly ignored (escaped).
else if c == '\\' {
mode |= TOK_MODE_CHAR_ESCAPE;
} else if c == '#' && is_token_begin {
self.token_cursor = comment_end(&self.start, self.token_cursor) - 1;
} else if c == '(' {
paran_offsets.push(self.token_cursor);
expecting.push(')');
mode |= TOK_MODE_SUBSHELL;
} else if c == '{' {
brace_offsets.push(self.token_cursor);
expecting.push('}');
mode |= TOK_MODE_CURLY_BRACES;
} else if c == ')' {
if expecting.last() == Some(&'}') {
return self.call_error(
TokenizerError::expected_bclose_found_pclose,
self.token_cursor,
self.token_cursor,
Some(1),
1,
);
}
if paran_offsets.is_empty() {
return self.call_error(
TokenizerError::closing_unopened_subshell,
self.token_cursor,
self.token_cursor,
Some(1),
1,
);
}
paran_offsets.pop();
if paran_offsets.is_empty() {
mode &= !TOK_MODE_SUBSHELL;
}
expecting.pop();
// Check if the ) completed a quoted command substitution.
if quoted_cmdsubs.last() == Some(¶n_offsets.len()) {
quoted_cmdsubs.pop();
// The "$(" part of a quoted command substitution closes double quotes. To keep
// quotes balanced, act as if there was an invisible double quote after the ")".
if let Err(error_loc) =
process_opening_quote(self, &mut quoted_cmdsubs, ¶n_offsets, '"')
{
if !self.accept_unfinished {
return self.call_error(
TokenizerError::unterminated_quote,
buff_start,
error_loc,
None,
0,
);
}
break;
}
}
} else if c == '}' {
if expecting.last() == Some(&')') {
return self.call_error(
TokenizerError::expected_pclose_found_bclose,
self.token_cursor,
self.token_cursor,
Some(1),
1,
);
}
if brace_offsets.is_empty() {
return self.call_error(
TokenizerError::closing_unopened_brace,
self.token_cursor,
self.start.len(),
None,
0,
);
}
brace_offsets.pop();
if brace_offsets.is_empty() {
mode &= !TOK_MODE_CURLY_BRACES;
}
expecting.pop();
} else if c == '[' {
if self.token_cursor != buff_start {
mode |= TOK_MODE_ARRAY_BRACKETS;
slice_offset = self.token_cursor;
} else {
// This is actually allowed so the test operator `[` can be used as the head of a
// command
}
}
// Only exit bracket mode if we are in bracket mode.
// Reason: `]` can be a parameter, e.g. last parameter to `[` test alias.
// e.g. echo $argv[([ $x -eq $y ])] # must not end bracket mode on first bracket
else if c == ']' && (mode & TOK_MODE_ARRAY_BRACKETS) {
mode &= !TOK_MODE_ARRAY_BRACKETS;
} else if c == '\'' || c == '"' {
if let Err(error_loc) =
process_opening_quote(self, &mut quoted_cmdsubs, ¶n_offsets, c)
{
if !self.accept_unfinished {
return self.call_error(
TokenizerError::unterminated_quote,
buff_start,
error_loc,
None,
1,
);
}
break;
}
} else if mode == TOK_MODE_REGULAR_TEXT
&& !tok_is_string_character(
c,
self.start
.as_char_slice()
.get(self.token_cursor + 1)
.copied(),
)
{
break;
}
let next = self
.start
.as_char_slice()
.get(self.token_cursor + 1)
.copied();
is_token_begin = is_token_delimiter(c, next);
self.token_cursor += 1;
}
if !self.accept_unfinished && mode != TOK_MODE_REGULAR_TEXT {
// These are all "unterminated", so the only char we can mark as an error
// is the opener (the closing char could be anywhere!)
//
// (except for TOK_MODE_CHAR_ESCAPE, which is one long by definition)
if mode & TOK_MODE_CHAR_ESCAPE {
return self.call_error(
TokenizerError::unterminated_escape,
buff_start,
self.token_cursor - 1,
None,
1,
);
} else if mode & TOK_MODE_ARRAY_BRACKETS {
return self.call_error(
TokenizerError::unterminated_slice,
buff_start,
slice_offset,
None,
1,
);
} else if mode & TOK_MODE_SUBSHELL {
assert!(!paran_offsets.is_empty());
let offset_of_open_paran = *paran_offsets.last().unwrap();
return self.call_error(
TokenizerError::unterminated_subshell,
buff_start,
offset_of_open_paran,
None,
1,
);
} else if mode & TOK_MODE_CURLY_BRACES {
assert!(!brace_offsets.is_empty());
let offset_of_open_brace = *brace_offsets.last().unwrap();
return self.call_error(
TokenizerError::unterminated_brace,
buff_start,
offset_of_open_brace,
None,
1,
);
} else {
panic!("Unknown non-regular-text mode");
}
}
let mut result = Tok::new(TokenType::string);
result.set_offset(buff_start);
result.set_length(self.token_cursor - buff_start);
result
}
}
pub fn quote_end(s: &wstr, mut pos: usize, quote: char) -> Option<usize> {
loop {
pos += 1;
let c = s.try_char_at(pos)?;
if c == '\\' {
pos += 1;
} else if c == quote ||
// Command substitutions also end a double quoted string. This is how we
// support command substitutions inside double quotes.
(quote == '"' && c == '$' && s.as_char_slice().get(pos+1) == Some(&'('))
{
return Some(pos);
}
}
}
pub fn comment_end(s: &wstr, mut pos: usize) -> usize {
loop {
pos += 1;
if pos == s.len() || s.char_at(pos) == '\n' {
return pos;
}
}
}
/// Tests if this character can be a part of a string. Hash (#) starts a comment if it's the first
/// character in a token; otherwise it is considered a string character. See issue #953.
fn tok_is_string_character(c: char, next: Option<char>) -> bool {
match c {
// Unconditional separators.
'\0' | ' ' | '\n' | '|' | '\t' | ';' | '\r' | '<' | '>' => false,
'&' => {
if feature_test(FeatureFlag::ampersand_nobg_in_token) {
// Unlike in other shells, '&' is not special if followed by a string character.
next.map(|nc| tok_is_string_character(nc, None))
.unwrap_or(false)
} else {
false
}
}
_ => true,
}
}
/// Quick test to catch the most common 'non-magical' characters, makes read_string slightly faster
/// by adding a fast path for the most common characters. This is obviously not a suitable
/// replacement for iswalpha.
fn myal(c: char) -> bool {
('a'..='z').contains(&c) || ('A'..='Z').contains(&c)
}
#[derive(Clone, Copy, PartialEq, Eq)]
struct TokModes(u8);
const TOK_MODE_REGULAR_TEXT: TokModes = TokModes(0); // regular text
const TOK_MODE_SUBSHELL: TokModes = TokModes(1 << 0); // inside of subshell parentheses
const TOK_MODE_ARRAY_BRACKETS: TokModes = TokModes(1 << 1); // inside of array brackets
const TOK_MODE_CURLY_BRACES: TokModes = TokModes(1 << 2);
const TOK_MODE_CHAR_ESCAPE: TokModes = TokModes(1 << 3);
impl BitAnd for TokModes {
type Output = bool;
fn bitand(self, rhs: Self) -> Self::Output {
(self.0 & rhs.0) != 0
}
}
impl BitAndAssign for TokModes {
fn bitand_assign(&mut self, rhs: Self) {
self.0 &= rhs.0
}
}
impl BitOrAssign for TokModes {
fn bitor_assign(&mut self, rhs: Self) {
self.0 |= rhs.0
}
}
impl Not for TokModes {
type Output = TokModes;
fn not(self) -> Self::Output {
TokModes(!self.0)
}
}
/// Tests if this character can delimit tokens.
pub fn is_token_delimiter(c: char, next: Option<char>) -> bool {
c == '(' || !tok_is_string_character(c, next)
}
/// \return the first token from the string, skipping variable assignments like A=B.
pub fn tok_command(str: &wstr) -> WString {
let mut t = Tokenizer::new(str, TokFlags(0));
while let Some(token) = t.next() {
if token.type_ != TokenType::string {
return WString::new();
}
let text = t.text_of(&token);
if variable_assignment_equals_pos(text).is_some() {
continue;
}
return text.to_owned();
}
WString::new()
}
impl TryFrom<&wstr> for PipeOrRedir {
type Error = ();
/// Examples of supported syntaxes.
/// Note we are only responsible for parsing the redirection part, not 'cmd' or 'file'.
///
/// ```text
/// cmd | cmd normal pipe
/// cmd &| cmd normal pipe plus stderr-merge
/// cmd >| cmd pipe with explicit fd
/// cmd 2>| cmd pipe with explicit fd
/// cmd < file stdin redirection
/// cmd > file redirection
/// cmd >> file appending redirection
/// cmd >? file noclobber redirection
/// cmd >>? file appending noclobber redirection
/// cmd 2> file file redirection with explicit fd
/// cmd >&2 fd redirection with no explicit src fd (stdout is used)
/// cmd 1>&2 fd redirection with an explicit src fd
/// cmd <&2 fd redirection with no explicit src fd (stdin is used)
/// cmd 3<&0 fd redirection with an explicit src fd
/// cmd &> file redirection with stderr merge
/// cmd ^ file caret (stderr) redirection, perhaps disabled via feature flags
/// cmd ^^ file caret (stderr) redirection, perhaps disabled via feature flags
/// ```
fn try_from(buff: &wstr) -> Result<PipeOrRedir, ()> {
// Extract a range of leading fd.
let mut cursor = buff.chars().take_while(|c| c.is_ascii_digit()).count();
let fd_buff = &buff[..cursor];
let has_fd = !fd_buff.is_empty();
// Try consuming a given character.
// Return true if consumed. On success, advances cursor.
let try_consume = |cursor: &mut usize, c| -> bool {
if buff.char_at(*cursor) != c {
false
} else {
*cursor += 1;
true
}
};
// Like try_consume, but asserts on failure.
let consume = |cursor: &mut usize, c| {
assert!(buff.char_at(*cursor) == c, "Failed to consume char");
*cursor += 1;
};
let c = buff.char_at(cursor);
let mut result = PipeOrRedir {
fd: -1,
is_pipe: false,
mode: RedirectionMode::overwrite,
stderr_merge: false,
consumed: 0,
};
match c {
'|' => {
if has_fd {
// Like 123|
return Err(());
}
consume(&mut cursor, '|');
assert!(
buff.char_at(cursor) != '|',
"|| passed as redirection, this should have been handled as 'or' by the caller"
);
result.fd = STDOUT_FILENO;
result.is_pipe = true;
}
'>' => {
consume(&mut cursor, '>');
if try_consume(&mut cursor, '>') {
result.mode = RedirectionMode::append;
}
if try_consume(&mut cursor, '|') {
// Note we differ from bash here.
// Consider `echo foo 2>| bar`
// In fish, this is a *pipe*. Run bar as a command and attach foo's stderr to bar's
// stdin, while leaving stdout as tty.
// In bash, this is a *redirection* to bar as a file. It is like > but ignores
// noclobber.
result.is_pipe = true;
result.fd = if has_fd {
parse_fd(fd_buff) // like 2>|
} else {
STDOUT_FILENO
}; // like >|
} else if try_consume(&mut cursor, '&') {
// This is a redirection to an fd.
// Note that we allow ">>&", but it's still just writing to the fd - "appending" to
// it doesn't make sense.
result.mode = RedirectionMode::fd;
result.fd = if has_fd {
parse_fd(fd_buff) // like 1>&2
} else {
STDOUT_FILENO // like >&2
};
} else {
// This is a redirection to a file.
result.fd = if has_fd {
parse_fd(fd_buff) // like 1> file.txt
} else {
STDOUT_FILENO // like > file.txt
};
if result.mode != RedirectionMode::append {
result.mode = RedirectionMode::overwrite;
}
// Note 'echo abc >>? file' is valid: it means append and noclobber.
// But here "noclobber" means the file must not exist, so appending
// can be ignored.
if try_consume(&mut cursor, '?') {
result.mode = RedirectionMode::noclob;
}
}
}
'<' => {
consume(&mut cursor, '<');
if try_consume(&mut cursor, '&') {
result.mode = RedirectionMode::fd;
} else if try_consume(&mut cursor, '?') {
// <? foo try-input redirection (uses /dev/null if file can't be used).
result.mode = RedirectionMode::try_input;
} else {
result.mode = RedirectionMode::input;
}
result.fd = if has_fd {
parse_fd(fd_buff) // like 1<&3 or 1< /tmp/file.txt