rust/src/formatting.rs

648 lines
20 KiB
Rust

// High level formatting functions.
use std::collections::HashMap;
use std::io::{self, Write};
use std::time::{Duration, Instant};
use rustc_ast::ast;
use rustc_span::Span;
use self::newline_style::apply_newline_style;
use crate::comment::{CharClasses, FullCodeCharKind};
use crate::config::{Config, FileName, Verbosity};
use crate::formatting::generated::is_generated_file;
use crate::modules::Module;
use crate::parse::parser::{DirectoryOwnership, Parser, ParserError};
use crate::parse::session::ParseSess;
use crate::utils::{contains_skip, count_newlines};
use crate::visitor::FmtVisitor;
use crate::{modules, source_file, ErrorKind, FormatReport, Input, Session};
mod generated;
mod newline_style;
// A map of the files of a crate, with their new content
pub(crate) type SourceFile = Vec<FileRecord>;
pub(crate) type FileRecord = (FileName, String);
impl<'b, T: Write + 'b> Session<'b, T> {
pub(crate) fn format_input_inner(
&mut self,
input: Input,
is_macro_def: bool,
) -> Result<FormatReport, ErrorKind> {
if !self.config.version_meets_requirement() {
return Err(ErrorKind::VersionMismatch);
}
rustc_span::create_session_if_not_set_then(self.config.edition().into(), |_| {
if self.config.disable_all_formatting() {
// When the input is from stdin, echo back the input.
return match input {
Input::Text(ref buf) => echo_back_stdin(buf),
_ => Ok(FormatReport::new()),
};
}
let config = &self.config.clone();
let format_result = format_project(input, config, self, is_macro_def);
format_result.map(|report| {
self.errors.add(&report.internal.borrow().1);
report
})
})
}
}
/// Determine if a module should be skipped. True if the module should be skipped, false otherwise.
fn should_skip_module<T: FormatHandler>(
config: &Config,
context: &FormatContext<'_, T>,
input_is_stdin: bool,
main_file: &FileName,
path: &FileName,
module: &Module<'_>,
) -> bool {
if contains_skip(module.attrs()) {
return true;
}
if config.skip_children() && path != main_file {
return true;
}
if !input_is_stdin && context.ignore_file(path) {
return true;
}
// FIXME(calebcartwright) - we need to determine how we'll handle the
// `format_generated_files` option with stdin based input.
if !input_is_stdin && !config.format_generated_files() {
let source_file = context.parse_session.span_to_file_contents(module.span);
let src = source_file.src.as_ref().expect("SourceFile without src");
if is_generated_file(src) {
return true;
}
}
false
}
fn echo_back_stdin(input: &str) -> Result<FormatReport, ErrorKind> {
if let Err(e) = io::stdout().write_all(input.as_bytes()) {
return Err(From::from(e));
}
Ok(FormatReport::new())
}
// Format an entire crate (or subset of the module tree).
fn format_project<T: FormatHandler>(
input: Input,
config: &Config,
handler: &mut T,
is_macro_def: bool,
) -> Result<FormatReport, ErrorKind> {
let mut timer = Timer::start();
let main_file = input.file_name();
let input_is_stdin = main_file == FileName::Stdin;
let parse_session = ParseSess::new(config)?;
if config.skip_children() && parse_session.ignore_file(&main_file) {
return Ok(FormatReport::new());
}
// Parse the crate.
let mut report = FormatReport::new();
let directory_ownership = input.to_directory_ownership();
let krate = match Parser::parse_crate(input, &parse_session) {
Ok(krate) => krate,
// Surface parse error via Session (errors are merged there from report)
Err(e) => {
let forbid_verbose = input_is_stdin || e != ParserError::ParsePanicError;
should_emit_verbose(forbid_verbose, config, || {
eprintln!("The Rust parser panicked");
});
report.add_parsing_error();
return Ok(report);
}
};
let mut context = FormatContext::new(&krate, report, parse_session, config, handler);
let files = modules::ModResolver::new(
&context.parse_session,
directory_ownership.unwrap_or(DirectoryOwnership::UnownedViaBlock),
!input_is_stdin && !config.skip_children(),
)
.visit_crate(&krate)?
.into_iter()
.filter(|(path, module)| {
input_is_stdin
|| !should_skip_module(config, &context, input_is_stdin, &main_file, path, module)
})
.collect::<Vec<_>>();
timer = timer.done_parsing();
// Suppress error output if we have to do any further parsing.
context.parse_session.set_silent_emitter();
for (path, module) in files {
if input_is_stdin && contains_skip(module.attrs()) {
return echo_back_stdin(
context
.parse_session
.snippet_provider(module.span)
.entire_snippet(),
);
}
should_emit_verbose(input_is_stdin, config, || println!("Formatting {}", path));
context.format_file(path, &module, is_macro_def)?;
}
timer = timer.done_formatting();
should_emit_verbose(input_is_stdin, config, || {
println!(
"Spent {0:.3} secs in the parsing phase, and {1:.3} secs in the formatting phase",
timer.get_parse_time(),
timer.get_format_time(),
)
});
Ok(context.report)
}
// Used for formatting files.
struct FormatContext<'a, T: FormatHandler> {
krate: &'a ast::Crate,
report: FormatReport,
parse_session: ParseSess,
config: &'a Config,
handler: &'a mut T,
}
impl<'a, T: FormatHandler + 'a> FormatContext<'a, T> {
fn new(
krate: &'a ast::Crate,
report: FormatReport,
parse_session: ParseSess,
config: &'a Config,
handler: &'a mut T,
) -> Self {
FormatContext {
krate,
report,
parse_session,
config,
handler,
}
}
fn ignore_file(&self, path: &FileName) -> bool {
self.parse_session.ignore_file(path)
}
// Formats a single file/module.
fn format_file(
&mut self,
path: FileName,
module: &Module<'_>,
is_macro_def: bool,
) -> Result<(), ErrorKind> {
let snippet_provider = self.parse_session.snippet_provider(module.span);
let mut visitor = FmtVisitor::from_parse_sess(
&self.parse_session,
self.config,
&snippet_provider,
self.report.clone(),
);
visitor.skip_context.update_with_attrs(&self.krate.attrs);
visitor.is_macro_def = is_macro_def;
visitor.last_pos = snippet_provider.start_pos();
visitor.skip_empty_lines(snippet_provider.end_pos());
visitor.format_separate_mod(module, snippet_provider.end_pos());
debug_assert_eq!(
visitor.line_number,
count_newlines(&visitor.buffer),
"failed in format_file visitor.buffer:\n {:?}",
&visitor.buffer
);
// For some reason, the source_map does not include terminating
// newlines so we must add one on for each file. This is sad.
source_file::append_newline(&mut visitor.buffer);
format_lines(
&mut visitor.buffer,
&path,
&visitor.skipped_range.borrow(),
self.config,
&self.report,
);
apply_newline_style(
self.config.newline_style(),
&mut visitor.buffer,
snippet_provider.entire_snippet(),
);
if visitor.macro_rewrite_failure {
self.report.add_macro_format_failure();
}
self.report
.add_non_formatted_ranges(visitor.skipped_range.borrow().clone());
self.handler.handle_formatted_file(
&self.parse_session,
path,
visitor.buffer.to_owned(),
&mut self.report,
)
}
}
// Handle the results of formatting.
trait FormatHandler {
fn handle_formatted_file(
&mut self,
parse_session: &ParseSess,
path: FileName,
result: String,
report: &mut FormatReport,
) -> Result<(), ErrorKind>;
}
impl<'b, T: Write + 'b> FormatHandler for Session<'b, T> {
// Called for each formatted file.
fn handle_formatted_file(
&mut self,
parse_session: &ParseSess,
path: FileName,
result: String,
report: &mut FormatReport,
) -> Result<(), ErrorKind> {
if let Some(ref mut out) = self.out {
match source_file::write_file(
Some(parse_session),
&path,
&result,
out,
&mut *self.emitter,
self.config.newline_style(),
) {
Ok(ref result) if result.has_diff => report.add_diff(),
Err(e) => {
// Create a new error with path_str to help users see which files failed
let err_msg = format!("{path}: {e}");
return Err(io::Error::new(e.kind(), err_msg).into());
}
_ => {}
}
}
self.source_file.push((path, result));
Ok(())
}
}
pub(crate) struct FormattingError {
pub(crate) line: usize,
pub(crate) kind: ErrorKind,
is_comment: bool,
is_string: bool,
pub(crate) line_buffer: String,
}
impl FormattingError {
pub(crate) fn from_span(
span: Span,
parse_sess: &ParseSess,
kind: ErrorKind,
) -> FormattingError {
FormattingError {
line: parse_sess.line_of_byte_pos(span.lo()),
is_comment: kind.is_comment(),
kind,
is_string: false,
line_buffer: parse_sess.span_to_first_line_string(span),
}
}
pub(crate) fn is_internal(&self) -> bool {
match self.kind {
ErrorKind::LineOverflow(..)
| ErrorKind::TrailingWhitespace
| ErrorKind::IoError(_)
| ErrorKind::ParseError
| ErrorKind::LostComment => true,
_ => false,
}
}
pub(crate) fn msg_suffix(&self) -> &str {
if self.is_comment || self.is_string {
"set `error_on_unformatted = false` to suppress \
the warning against comments or string literals\n"
} else {
""
}
}
// (space, target)
pub(crate) fn format_len(&self) -> (usize, usize) {
match self.kind {
ErrorKind::LineOverflow(found, max) => (max, found - max),
ErrorKind::TrailingWhitespace
| ErrorKind::DeprecatedAttr
| ErrorKind::BadAttr
| ErrorKind::LostComment => {
let trailing_ws_start = self
.line_buffer
.rfind(|c: char| !c.is_whitespace())
.map(|pos| pos + 1)
.unwrap_or(0);
(
trailing_ws_start,
self.line_buffer.len() - trailing_ws_start,
)
}
_ => unreachable!(),
}
}
}
pub(crate) type FormatErrorMap = HashMap<FileName, Vec<FormattingError>>;
#[derive(Default, Debug, PartialEq)]
pub(crate) struct ReportedErrors {
// Encountered e.g., an IO error.
pub(crate) has_operational_errors: bool,
// Failed to reformat code because of parsing errors.
pub(crate) has_parsing_errors: bool,
// Code is valid, but it is impossible to format it properly.
pub(crate) has_formatting_errors: bool,
// Code contains macro call that was unable to format.
pub(crate) has_macro_format_failure: bool,
// Failed an opt-in checking.
pub(crate) has_check_errors: bool,
/// Formatted code differs from existing code (--check only).
pub(crate) has_diff: bool,
/// Formatted code missed something, like lost comments or extra trailing space
pub(crate) has_unformatted_code_errors: bool,
}
impl ReportedErrors {
/// Combine two summaries together.
pub(crate) fn add(&mut self, other: &ReportedErrors) {
self.has_operational_errors |= other.has_operational_errors;
self.has_parsing_errors |= other.has_parsing_errors;
self.has_formatting_errors |= other.has_formatting_errors;
self.has_macro_format_failure |= other.has_macro_format_failure;
self.has_check_errors |= other.has_check_errors;
self.has_diff |= other.has_diff;
self.has_unformatted_code_errors |= other.has_unformatted_code_errors;
}
}
#[derive(Clone, Copy, Debug)]
enum Timer {
Disabled,
Initialized(Instant),
DoneParsing(Instant, Instant),
DoneFormatting(Instant, Instant, Instant),
}
impl Timer {
fn start() -> Timer {
if cfg!(target_arch = "wasm32") {
Timer::Disabled
} else {
Timer::Initialized(Instant::now())
}
}
fn done_parsing(self) -> Self {
match self {
Timer::Disabled => Timer::Disabled,
Timer::Initialized(init_time) => Timer::DoneParsing(init_time, Instant::now()),
_ => panic!("Timer can only transition to DoneParsing from Initialized state"),
}
}
fn done_formatting(self) -> Self {
match self {
Timer::Disabled => Timer::Disabled,
Timer::DoneParsing(init_time, parse_time) => {
Timer::DoneFormatting(init_time, parse_time, Instant::now())
}
_ => panic!("Timer can only transition to DoneFormatting from DoneParsing state"),
}
}
/// Returns the time it took to parse the source files in seconds.
fn get_parse_time(&self) -> f32 {
match *self {
Timer::Disabled => panic!("this platform cannot time execution"),
Timer::DoneParsing(init, parse_time) | Timer::DoneFormatting(init, parse_time, _) => {
// This should never underflow since `Instant::now()` guarantees monotonicity.
Self::duration_to_f32(parse_time.duration_since(init))
}
Timer::Initialized(..) => unreachable!(),
}
}
/// Returns the time it took to go from the parsed AST to the formatted output. Parsing time is
/// not included.
fn get_format_time(&self) -> f32 {
match *self {
Timer::Disabled => panic!("this platform cannot time execution"),
Timer::DoneFormatting(_init, parse_time, format_time) => {
Self::duration_to_f32(format_time.duration_since(parse_time))
}
Timer::DoneParsing(..) | Timer::Initialized(..) => unreachable!(),
}
}
fn duration_to_f32(d: Duration) -> f32 {
d.as_secs() as f32 + d.subsec_nanos() as f32 / 1_000_000_000f32
}
}
// Formatting done on a char by char or line by line basis.
// FIXME(#20): other stuff for parity with make tidy.
fn format_lines(
text: &mut String,
name: &FileName,
skipped_range: &[(usize, usize)],
config: &Config,
report: &FormatReport,
) {
let mut formatter = FormatLines::new(name, skipped_range, config);
formatter.iterate(text);
if formatter.newline_count > 1 {
debug!("track truncate: {} {}", text.len(), formatter.newline_count);
let line = text.len() - formatter.newline_count + 1;
text.truncate(line);
}
report.append(name.clone(), formatter.errors);
}
struct FormatLines<'a> {
name: &'a FileName,
skipped_range: &'a [(usize, usize)],
last_was_space: bool,
line_len: usize,
cur_line: usize,
newline_count: usize,
errors: Vec<FormattingError>,
line_buffer: String,
current_line_contains_string_literal: bool,
format_line: bool,
config: &'a Config,
}
impl<'a> FormatLines<'a> {
fn new(
name: &'a FileName,
skipped_range: &'a [(usize, usize)],
config: &'a Config,
) -> FormatLines<'a> {
FormatLines {
name,
skipped_range,
last_was_space: false,
line_len: 0,
cur_line: 1,
newline_count: 0,
errors: vec![],
line_buffer: String::with_capacity(config.max_width() * 2),
current_line_contains_string_literal: false,
format_line: config.file_lines().contains_line(name, 1),
config,
}
}
// Iterate over the chars in the file map.
fn iterate(&mut self, text: &mut String) {
for (kind, c) in CharClasses::new(text.chars()) {
if c == '\r' {
continue;
}
if c == '\n' {
self.new_line(kind);
} else {
self.char(c, kind);
}
}
}
fn new_line(&mut self, kind: FullCodeCharKind) {
if self.format_line {
// Check for (and record) trailing whitespace.
if self.last_was_space {
if self.should_report_error(kind, &ErrorKind::TrailingWhitespace)
&& !self.is_skipped_line()
{
self.push_err(
ErrorKind::TrailingWhitespace,
kind.is_comment(),
kind.is_string(),
);
}
self.line_len -= 1;
}
// Check for any line width errors we couldn't correct.
let error_kind = ErrorKind::LineOverflow(self.line_len, self.config.max_width());
if self.line_len > self.config.max_width()
&& !self.is_skipped_line()
&& self.should_report_error(kind, &error_kind)
{
let is_string = self.current_line_contains_string_literal;
self.push_err(error_kind, kind.is_comment(), is_string);
}
}
self.line_len = 0;
self.cur_line += 1;
self.format_line = self
.config
.file_lines()
.contains_line(self.name, self.cur_line);
self.newline_count += 1;
self.last_was_space = false;
self.line_buffer.clear();
self.current_line_contains_string_literal = false;
}
fn char(&mut self, c: char, kind: FullCodeCharKind) {
self.newline_count = 0;
self.line_len += if c == '\t' {
self.config.tab_spaces()
} else {
1
};
self.last_was_space = c.is_whitespace();
self.line_buffer.push(c);
if kind.is_string() {
self.current_line_contains_string_literal = true;
}
}
fn push_err(&mut self, kind: ErrorKind, is_comment: bool, is_string: bool) {
self.errors.push(FormattingError {
line: self.cur_line,
kind,
is_comment,
is_string,
line_buffer: self.line_buffer.clone(),
});
}
fn should_report_error(&self, char_kind: FullCodeCharKind, error_kind: &ErrorKind) -> bool {
let allow_error_report = if char_kind.is_comment()
|| self.current_line_contains_string_literal
|| error_kind.is_comment()
{
self.config.error_on_unformatted()
} else {
true
};
match error_kind {
ErrorKind::LineOverflow(..) => {
self.config.error_on_line_overflow() && allow_error_report
}
ErrorKind::TrailingWhitespace | ErrorKind::LostComment => allow_error_report,
_ => true,
}
}
/// Returns `true` if the line with the given line number was skipped by `#[rustfmt::skip]`.
fn is_skipped_line(&self) -> bool {
self.skipped_range
.iter()
.any(|&(lo, hi)| lo <= self.cur_line && self.cur_line <= hi)
}
}
fn should_emit_verbose<F>(forbid_verbose_output: bool, config: &Config, f: F)
where
F: Fn(),
{
if config.verbose() == Verbosity::Verbose && !forbid_verbose_output {
f();
}
}