-use std::borrow::Cow;
-use std::iter;
-use std::ops::{Deref, Range};
-
-use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
-use clippy_utils::source::{snippet_opt, snippet_with_applicability};
-use rustc_ast::ast::{Expr, ExprKind, Impl, Item, ItemKind, MacCall, Path, StrLit, StrStyle};
-use rustc_ast::token::{self, LitKind};
-use rustc_ast::tokenstream::TokenStream;
-use rustc_errors::{Applicability, DiagnosticBuilder};
-use rustc_lexer::unescape::{self, EscapeError};
-use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
-use rustc_parse::parser;
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
+use clippy_utils::macros::{root_macro_call_first_node, FormatArgsExpn, MacroCall};
+use clippy_utils::source::{expand_past_previous_comma, snippet_opt};
+use rustc_ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, HirIdMap, Impl, Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_session::{declare_tool_lint, impl_lint_pass};
-use rustc_span::symbol::{kw, Symbol};
-use rustc_span::{sym, BytePos, InnerSpan, Span, DUMMY_SP};
+use rustc_span::{sym, BytePos};
declare_clippy_lint! {
/// ### What it does
/// application and might forget to remove those prints afterward.
///
/// ### Known problems
- /// * Only catches `print!` and `println!` calls.
- /// * The lint level is unaffected by crate attributes. The level can still
- /// be set for functions, modules and other items. To change the level for
- /// the entire crate, please use command line flags. More information and a
- /// configuration example can be found in [clippy#6610].
- ///
- /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
+ /// Only catches `print!` and `println!` calls.
///
/// ### Example
/// ```rust
/// application and might forget to remove those prints afterward.
///
/// ### Known problems
- /// * Only catches `eprint!` and `eprintln!` calls.
- /// * The lint level is unaffected by crate attributes. The level can still
- /// be set for functions, modules and other items. To change the level for
- /// the entire crate, please use command line flags. More information and a
- /// configuration example can be found in [clippy#6610].
- ///
- /// [clippy#6610]: https://github.com/rust-lang/rust-clippy/issues/6610#issuecomment-977120558
+ /// Only catches `eprint!` and `eprintln!` calls.
///
/// ### Example
/// ```rust
/// (c.f., https://github.com/matthiaskrgr/rust-str-bench) and unnecessary
/// (i.e., just put the literal in the format string)
///
- /// ### Known problems
- /// Will also warn with macro calls as arguments that expand to literals
- /// -- e.g., `println!("{}", env!("FOO"))`.
- ///
/// ### Example
/// ```rust
/// println!("{}", "foo");
/// (c.f., https://github.com/matthiaskrgr/rust-str-bench) and unnecessary
/// (i.e., just put the literal in the format string)
///
- /// ### Known problems
- /// Will also warn with macro calls as arguments that expand to literals
- /// -- e.g., `writeln!(buf, "{}", env!("FOO"))`.
- ///
/// ### Example
/// ```rust
/// # use std::fmt::Write;
PRINT_LITERAL,
WRITE_WITH_NEWLINE,
WRITELN_EMPTY_STRING,
- WRITE_LITERAL
+ WRITE_LITERAL,
]);
-impl EarlyLintPass for Write {
- fn check_item(&mut self, _: &EarlyContext<'_>, item: &Item) {
- if let ItemKind::Impl(box Impl {
- of_trait: Some(trait_ref),
- ..
- }) = &item.kind
- {
- let trait_name = trait_ref
- .path
- .segments
- .iter()
- .last()
- .expect("path has at least one segment")
- .ident
- .name;
- if trait_name == sym::Debug {
- self.in_debug_impl = true;
- }
+impl<'tcx> LateLintPass<'tcx> for Write {
+ fn check_item(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+ if is_debug_impl(cx, item) {
+ self.in_debug_impl = true;
}
}
- fn check_item_post(&mut self, _: &EarlyContext<'_>, _: &Item) {
- self.in_debug_impl = false;
+ fn check_item_post(&mut self, cx: &LateContext<'_>, item: &Item<'_>) {
+ if is_debug_impl(cx, item) {
+ self.in_debug_impl = false;
+ }
}
- fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &MacCall) {
- fn is_build_script(cx: &EarlyContext<'_>) -> bool {
- // Cargo sets the crate name for build scripts to `build_script_build`
- cx.sess()
- .opts
- .crate_name
- .as_ref()
- .map_or(false, |crate_name| crate_name == "build_script_build")
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
+ let Some(macro_call) = root_macro_call_first_node(cx, expr) else { return };
+ let Some(diag_name) = cx.tcx.get_diagnostic_name(macro_call.def_id) else { return };
+ let Some(name) = diag_name.as_str().strip_suffix("_macro") else { return };
+
+ let is_build_script = cx
+ .sess()
+ .opts
+ .crate_name
+ .as_ref()
+ .map_or(false, |crate_name| crate_name == "build_script_build");
+
+ match diag_name {
+ sym::print_macro | sym::println_macro => {
+ if !is_build_script {
+ span_lint(cx, PRINT_STDOUT, macro_call.span, &format!("use of `{name}!`"));
+ }
+ },
+ sym::eprint_macro | sym::eprintln_macro => {
+ span_lint(cx, PRINT_STDERR, macro_call.span, &format!("use of `{name}!`"));
+ },
+ sym::write_macro | sym::writeln_macro => {},
+ _ => return,
}
- if mac.path == sym!(print) {
- if !is_build_script(cx) {
- span_lint(cx, PRINT_STDOUT, mac.span(), "use of `print!`");
- }
- self.lint_print_with_newline(cx, mac);
- } else if mac.path == sym!(println) {
- if !is_build_script(cx) {
- span_lint(cx, PRINT_STDOUT, mac.span(), "use of `println!`");
- }
- self.lint_println_empty_string(cx, mac);
- } else if mac.path == sym!(eprint) {
- span_lint(cx, PRINT_STDERR, mac.span(), "use of `eprint!`");
- self.lint_print_with_newline(cx, mac);
- } else if mac.path == sym!(eprintln) {
- span_lint(cx, PRINT_STDERR, mac.span(), "use of `eprintln!`");
- self.lint_println_empty_string(cx, mac);
- } else if mac.path == sym!(write) {
- if let (Some(fmt_str), dest) = self.check_tts(cx, mac.args.inner_tokens(), true) {
- if check_newlines(&fmt_str) {
- let (nl_span, only_nl) = newline_span(&fmt_str);
- let nl_span = match (dest, only_nl) {
- // Special case of `write!(buf, "\n")`: Mark everything from the end of
- // `buf` for removal so no trailing comma [`writeln!(buf, )`] remains.
- (Some(dest_expr), true) => nl_span.with_lo(dest_expr.span.hi()),
- _ => nl_span,
- };
- span_lint_and_then(
- cx,
- WRITE_WITH_NEWLINE,
- mac.span(),
- "using `write!()` with a format string that ends in a single newline",
- |err| {
- err.multipart_suggestion(
- "use `writeln!()` instead",
- vec![(mac.path.span, String::from("writeln")), (nl_span, String::new())],
- Applicability::MachineApplicable,
- );
- },
- );
- }
- }
- } else if mac.path == sym!(writeln) {
- if let (Some(fmt_str), expr) = self.check_tts(cx, mac.args.inner_tokens(), true) {
- if fmt_str.symbol == kw::Empty {
- let mut applicability = Applicability::MachineApplicable;
- let suggestion = if let Some(e) = expr {
- snippet_with_applicability(cx, e.span, "v", &mut applicability)
- } else {
- applicability = Applicability::HasPlaceholders;
- Cow::Borrowed("v")
- };
-
- span_lint_and_sugg(
- cx,
- WRITELN_EMPTY_STRING,
- mac.span(),
- format!("using `writeln!({}, \"\")`", suggestion).as_str(),
- "replace it with",
- format!("writeln!({})", suggestion),
- applicability,
- );
+ let Some(format_args) = FormatArgsExpn::find_nested(cx, expr, macro_call.expn) else { return };
+
+ // ignore `writeln!(w)` and `write!(v, some_macro!())`
+ if format_args.format_string.span.from_expansion() {
+ return;
+ }
+
+ match diag_name {
+ sym::print_macro | sym::eprint_macro | sym::write_macro => {
+ check_newline(cx, &format_args, ¯o_call, name);
+ },
+ sym::println_macro | sym::eprintln_macro | sym::writeln_macro => {
+ check_empty_string(cx, &format_args, ¯o_call, name);
+ },
+ _ => {},
+ }
+
+ check_literal(cx, &format_args, name);
+
+ if !self.in_debug_impl {
+ for arg in &format_args.args {
+ if arg.format.r#trait == sym::Debug {
+ span_lint(cx, USE_DEBUG, arg.span, "use of `Debug`-based formatting");
}
}
}
}
}
-
-/// Given a format string that ends in a newline and its span, calculates the span of the
-/// newline, or the format string itself if the format string consists solely of a newline.
-/// Return this and a boolean indicating whether it only consisted of a newline.
-fn newline_span(fmtstr: &StrLit) -> (Span, bool) {
- let sp = fmtstr.span;
- let contents = fmtstr.symbol.as_str();
-
- if contents == r"\n" {
- return (sp, true);
+fn is_debug_impl(cx: &LateContext<'_>, item: &Item<'_>) -> bool {
+ if let ItemKind::Impl(Impl { of_trait: Some(trait_ref), .. }) = &item.kind
+ && let Some(trait_id) = trait_ref.trait_def_id()
+ {
+ cx.tcx.is_diagnostic_item(sym::Debug, trait_id)
+ } else {
+ false
}
+}
- let newline_sp_hi = sp.hi()
- - match fmtstr.style {
- StrStyle::Cooked => BytePos(1),
- StrStyle::Raw(hashes) => BytePos((1 + hashes).into()),
- };
+fn check_newline(cx: &LateContext<'_>, format_args: &FormatArgsExpn<'_>, macro_call: &MacroCall, name: &str) {
+ let format_string_parts = &format_args.format_string.parts;
+ let mut format_string_span = format_args.format_string.span;
- let newline_sp_len = if contents.ends_with('\n') {
- BytePos(1)
- } else if contents.ends_with(r"\n") {
- BytePos(2)
- } else {
- panic!("expected format string to contain a newline");
+ let Some(last) = format_string_parts.last() else { return };
+
+ let count_vertical_whitespace = || {
+ format_string_parts
+ .iter()
+ .flat_map(|part| part.as_str().chars())
+ .filter(|ch| matches!(ch, '\r' | '\n'))
+ .count()
};
- (sp.with_lo(newline_sp_hi - newline_sp_len).with_hi(newline_sp_hi), false)
-}
+ if last.as_str().ends_with('\n')
+ // ignore format strings with other internal vertical whitespace
+ && count_vertical_whitespace() == 1
-/// Stores a list of replacement spans for each argument, but only if all the replacements used an
-/// empty format string.
-#[derive(Default)]
-struct SimpleFormatArgs {
- unnamed: Vec<Vec<Span>>,
- named: Vec<(Symbol, Vec<Span>)>,
-}
-impl SimpleFormatArgs {
- fn get_unnamed(&self) -> impl Iterator<Item = &[Span]> {
- self.unnamed.iter().map(|x| match x.as_slice() {
- // Ignore the dummy span added from out of order format arguments.
- [DUMMY_SP] => &[],
- x => x,
- })
- }
+ // ignore trailing arguments: `print!("Issue\n{}", 1265);`
+ && format_string_parts.len() > format_args.args.len()
+ {
+ let lint = if name == "write" {
+ format_string_span = expand_past_previous_comma(cx, format_string_span);
- fn get_named(&self, n: &Path) -> &[Span] {
- self.named.iter().find(|x| *n == x.0).map_or(&[], |x| x.1.as_slice())
- }
-
- fn push(&mut self, arg: rustc_parse_format::Argument<'_>, span: Span) {
- use rustc_parse_format::{
- AlignUnknown, ArgumentImplicitlyIs, ArgumentIs, ArgumentNamed, CountImplied, FormatSpec,
+ WRITE_WITH_NEWLINE
+ } else {
+ PRINT_WITH_NEWLINE
};
- const SIMPLE: FormatSpec<'_> = FormatSpec {
- fill: None,
- align: AlignUnknown,
- flags: 0,
- precision: CountImplied,
- precision_span: None,
- width: CountImplied,
- width_span: None,
- ty: "",
- ty_span: None,
- };
+ span_lint_and_then(
+ cx,
+ lint,
+ macro_call.span,
+ &format!("using `{name}!()` with a format string that ends in a single newline"),
+ |diag| {
+ let name_span = cx.sess().source_map().span_until_char(macro_call.span, '!');
+ let Some(format_snippet) = snippet_opt(cx, format_string_span) else { return };
+
+ if format_string_parts.len() == 1 && last.as_str() == "\n" {
+ // print!("\n"), write!(f, "\n")
+
+ diag.multipart_suggestion(
+ &format!("use `{name}ln!` instead"),
+ vec![(name_span, format!("{name}ln")), (format_string_span, String::new())],
+ Applicability::MachineApplicable,
+ );
+ } else if format_snippet.ends_with("\\n\"") {
+ // print!("...\n"), write!(f, "...\n")
- match arg.position {
- ArgumentIs(n, _) | ArgumentImplicitlyIs(n) => {
- if self.unnamed.len() <= n {
- // Use a dummy span to mark all unseen arguments.
- self.unnamed.resize_with(n, || vec![DUMMY_SP]);
- if arg.format == SIMPLE {
- self.unnamed.push(vec![span]);
- } else {
- self.unnamed.push(Vec::new());
- }
- } else {
- let args = &mut self.unnamed[n];
- match (args.as_mut_slice(), arg.format == SIMPLE) {
- // A non-empty format string has been seen already.
- ([], _) => (),
- // Replace the dummy span, if it exists.
- ([dummy @ DUMMY_SP], true) => *dummy = span,
- ([_, ..], true) => args.push(span),
- ([_, ..], false) => *args = Vec::new(),
- }
- }
- },
- ArgumentNamed(n, _) => {
- let n = Symbol::intern(n);
- if let Some(x) = self.named.iter_mut().find(|x| x.0 == n) {
- match x.1.as_slice() {
- // A non-empty format string has been seen already.
- [] => (),
- [_, ..] if arg.format == SIMPLE => x.1.push(span),
- [_, ..] => x.1 = Vec::new(),
- }
- } else if arg.format == SIMPLE {
- self.named.push((n, vec![span]));
- } else {
- self.named.push((n, Vec::new()));
+ let hi = format_string_span.hi();
+ let newline_span = format_string_span.with_lo(hi - BytePos(3)).with_hi(hi - BytePos(1));
+
+ diag.multipart_suggestion(
+ &format!("use `{name}ln!` instead"),
+ vec![(name_span, format!("{name}ln")), (newline_span, String::new())],
+ Applicability::MachineApplicable,
+ );
}
},
- };
+ );
}
}
-impl Write {
- /// Parses a format string into a collection of spans for each argument. This only keeps track
- /// of empty format arguments. Will also lint usages of debug format strings outside of debug
- /// impls.
- fn parse_fmt_string(&self, cx: &EarlyContext<'_>, str_lit: &StrLit) -> Option<SimpleFormatArgs> {
- use rustc_parse_format::{ParseMode, Parser, Piece};
-
- let str_sym = str_lit.symbol_unescaped.as_str();
- let style = match str_lit.style {
- StrStyle::Cooked => None,
- StrStyle::Raw(n) => Some(n as usize),
- };
-
- let mut parser = Parser::new(str_sym, style, snippet_opt(cx, str_lit.span), false, ParseMode::Format);
- let mut args = SimpleFormatArgs::default();
-
- while let Some(arg) = parser.next() {
- let arg = match arg {
- Piece::String(_) => continue,
- Piece::NextArgument(arg) => arg,
- };
- let span = parser
- .arg_places
- .last()
- .map_or(DUMMY_SP, |&x| str_lit.span.from_inner(InnerSpan::new(x.start, x.end)));
-
- if !self.in_debug_impl && arg.format.ty == "?" {
- // FIXME: modify rustc's fmt string parser to give us the current span
- span_lint(cx, USE_DEBUG, span, "use of `Debug`-based formatting");
- }
-
- args.push(arg, span);
- }
-
- parser.errors.is_empty().then_some(args)
- }
+fn check_empty_string(cx: &LateContext<'_>, format_args: &FormatArgsExpn<'_>, macro_call: &MacroCall, name: &str) {
+ if let [part] = &format_args.format_string.parts[..]
+ && let mut span = format_args.format_string.span
+ && part.as_str() == "\n"
+ {
+ let lint = if name == "writeln" {
+ span = expand_past_previous_comma(cx, span);
- /// Checks the arguments of `print[ln]!` and `write[ln]!` calls. It will return a tuple of two
- /// `Option`s. The first `Option` of the tuple is the macro's format string. It includes
- /// the contents of the string, whether it's a raw string, and the span of the literal in the
- /// source. The second `Option` in the tuple is, in the `write[ln]!` case, the expression the
- /// `format_str` should be written to.
- ///
- /// Example:
- ///
- /// Calling this function on
- /// ```rust
- /// # use std::fmt::Write;
- /// # let mut buf = String::new();
- /// # let something = "something";
- /// writeln!(buf, "string to write: {}", something);
- /// ```
- /// will return
- /// ```rust,ignore
- /// (Some("string to write: {}"), Some(buf))
- /// ```
- fn check_tts<'a>(&self, cx: &EarlyContext<'a>, tts: TokenStream, is_write: bool) -> (Option<StrLit>, Option<Expr>) {
- let mut parser = parser::Parser::new(&cx.sess().parse_sess, tts, false, None);
- let expr = if is_write {
- match parser
- .parse_expr()
- .map(rustc_ast::ptr::P::into_inner)
- .map_err(DiagnosticBuilder::cancel)
- {
- // write!(e, ...)
- Ok(p) if parser.eat(&token::Comma) => Some(p),
- // write!(e) or error
- e => return (None, e.ok()),
- }
+ WRITELN_EMPTY_STRING
} else {
- None
+ PRINTLN_EMPTY_STRING
};
- let fmtstr = match parser.parse_str_lit() {
- Ok(fmtstr) => fmtstr,
- Err(_) => return (None, expr),
- };
+ span_lint_and_then(
+ cx,
+ lint,
+ macro_call.span,
+ &format!("empty string literal in `{name}!`"),
+ |diag| {
+ diag.span_suggestion(
+ span,
+ "remove the empty string",
+ String::new(),
+ Applicability::MachineApplicable,
+ );
+ },
+ );
+ }
+}
- let args = match self.parse_fmt_string(cx, &fmtstr) {
- Some(args) => args,
- None => return (Some(fmtstr), expr),
- };
+fn check_literal(cx: &LateContext<'_>, format_args: &FormatArgsExpn<'_>, name: &str) {
+ let mut counts = HirIdMap::<usize>::default();
+ for param in format_args.params() {
+ *counts.entry(param.value.hir_id).or_default() += 1;
+ }
- let lint = if is_write { WRITE_LITERAL } else { PRINT_LITERAL };
- let mut unnamed_args = args.get_unnamed();
- loop {
- if !parser.eat(&token::Comma) {
- return (Some(fmtstr), expr);
- }
+ for arg in &format_args.args {
+ let value = arg.param.value;
- let comma_span = parser.prev_token.span;
- let token_expr = if let Ok(expr) = parser.parse_expr().map_err(DiagnosticBuilder::cancel) {
- expr
- } else {
- return (Some(fmtstr), None);
+ if counts[&value.hir_id] == 1
+ && arg.format.is_default()
+ && let ExprKind::Lit(lit) = &value.kind
+ && !value.span.from_expansion()
+ && let Some(value_string) = snippet_opt(cx, value.span)
+ {
+ let (replacement, replace_raw) = match lit.node {
+ LitKind::Str(..) => extract_str_literal(&value_string),
+ LitKind::Char(ch) => (
+ match ch {
+ '"' => "\\\"",
+ '\'' => "'",
+ _ => &value_string[1..value_string.len() - 1],
+ }
+ .to_string(),
+ false,
+ ),
+ LitKind::Bool(b) => (b.to_string(), false),
+ _ => continue,
};
- let (fmt_spans, lit) = match &token_expr.kind {
- ExprKind::Lit(lit) => (unnamed_args.next().unwrap_or(&[]), lit),
- ExprKind::Assign(lhs, rhs, _) => match (&lhs.kind, &rhs.kind) {
- (ExprKind::Path(_, p), ExprKind::Lit(lit)) => (args.get_named(p), lit),
- _ => continue,
- },
- _ => {
- unnamed_args.next();
- continue;
- },
+
+ let lint = if name.starts_with("write") {
+ WRITE_LITERAL
+ } else {
+ PRINT_LITERAL
};
- let replacement: String = match lit.token.kind {
- LitKind::StrRaw(_) | LitKind::ByteStrRaw(_) if matches!(fmtstr.style, StrStyle::Raw(_)) => {
- lit.token.symbol.as_str().replace('{', "{{").replace('}', "}}")
+ let format_string_is_raw = format_args.format_string.style.is_some();
+ let replacement = match (format_string_is_raw, replace_raw) {
+ (false, false) => Some(replacement),
+ (false, true) => Some(replacement.replace('"', "\\\"").replace('\\', "\\\\")),
+ (true, false) => match conservative_unescape(&replacement) {
+ Ok(unescaped) => Some(unescaped),
+ Err(UnescapeErr::Lint) => None,
+ Err(UnescapeErr::Ignore) => continue,
},
- LitKind::Str | LitKind::ByteStr if matches!(fmtstr.style, StrStyle::Cooked) => {
- lit.token.symbol.as_str().replace('{', "{{").replace('}', "}}")
+ (true, true) => {
+ if replacement.contains(['#', '"']) {
+ None
+ } else {
+ Some(replacement)
+ }
},
- LitKind::StrRaw(_)
- | LitKind::Str
- | LitKind::ByteStrRaw(_)
- | LitKind::ByteStr
- | LitKind::Integer
- | LitKind::Float
- | LitKind::Err => continue,
- LitKind::Byte | LitKind::Char => match lit.token.symbol.as_str() {
- "\"" if matches!(fmtstr.style, StrStyle::Cooked) => "\\\"",
- "\"" if matches!(fmtstr.style, StrStyle::Raw(0)) => continue,
- "\\\\" if matches!(fmtstr.style, StrStyle::Raw(_)) => "\\",
- "\\'" => "'",
- "{" => "{{",
- "}" => "}}",
- x if matches!(fmtstr.style, StrStyle::Raw(_)) && x.starts_with('\\') => continue,
- x => x,
- }
- .into(),
- LitKind::Bool => lit.token.symbol.as_str().deref().into(),
};
- if !fmt_spans.is_empty() {
- span_lint_and_then(
- cx,
- lint,
- token_expr.span,
- "literal with an empty format string",
- |diag| {
+ span_lint_and_then(
+ cx,
+ lint,
+ value.span,
+ "literal with an empty format string",
+ |diag| {
+ if let Some(replacement) = replacement
+ // `format!("{}", "a")`, `format!("{named}", named = "b")
+ // ~~~~~ ~~~~~~~~~~~~~
+ && let Some(value_span) = format_args.value_with_prev_comma_span(value.hir_id)
+ {
+ let replacement = replacement.replace('{', "{{").replace('}', "}}");
diag.multipart_suggestion(
"try this",
- iter::once((comma_span.to(token_expr.span), String::new()))
- .chain(fmt_spans.iter().copied().zip(iter::repeat(replacement)))
- .collect(),
+ vec![(arg.span, replacement), (value_span, String::new())],
Applicability::MachineApplicable,
);
- },
- );
- }
- }
- }
-
- fn lint_println_empty_string(&self, cx: &EarlyContext<'_>, mac: &MacCall) {
- if let (Some(fmt_str), _) = self.check_tts(cx, mac.args.inner_tokens(), false) {
- if fmt_str.symbol == kw::Empty {
- let name = mac.path.segments[0].ident.name;
- span_lint_and_sugg(
- cx,
- PRINTLN_EMPTY_STRING,
- mac.span(),
- &format!("using `{}!(\"\")`", name),
- "replace it with",
- format!("{}!()", name),
- Applicability::MachineApplicable,
- );
- }
- }
- }
-
- fn lint_print_with_newline(&self, cx: &EarlyContext<'_>, mac: &MacCall) {
- if let (Some(fmt_str), _) = self.check_tts(cx, mac.args.inner_tokens(), false) {
- if check_newlines(&fmt_str) {
- let name = mac.path.segments[0].ident.name;
- let suggested = format!("{}ln", name);
- span_lint_and_then(
- cx,
- PRINT_WITH_NEWLINE,
- mac.span(),
- &format!("using `{}!()` with a format string that ends in a single newline", name),
- |err| {
- err.multipart_suggestion(
- &format!("use `{}!` instead", suggested),
- vec![(mac.path.span, suggested), (newline_span(&fmt_str).0, String::new())],
- Applicability::MachineApplicable,
- );
- },
- );
- }
+ }
+ },
+ );
}
}
}
-/// Checks if the format string contains a single newline that terminates it.
+/// Removes the raw marker, `#`s and quotes from a str, and returns if the literal is raw
+///
+/// `r#"a"#` -> (`a`, true)
///
-/// Literal and escaped newlines are both checked (only literal for raw strings).
-fn check_newlines(fmtstr: &StrLit) -> bool {
- let mut has_internal_newline = false;
- let mut last_was_cr = false;
- let mut should_lint = false;
+/// `"b"` -> (`b`, false)
+fn extract_str_literal(literal: &str) -> (String, bool) {
+ let (literal, raw) = match literal.strip_prefix('r') {
+ Some(stripped) => (stripped.trim_matches('#'), true),
+ None => (literal, false),
+ };
- let contents = fmtstr.symbol.as_str();
+ (literal[1..literal.len() - 1].to_string(), raw)
+}
- let mut cb = |r: Range<usize>, c: Result<char, EscapeError>| {
- let c = c.unwrap();
+enum UnescapeErr {
+ /// Should still be linted, can be manually resolved by author, e.g.
+ ///
+ /// ```ignore
+ /// print!(r"{}", '"');
+ /// ```
+ Lint,
+ /// Should not be linted, e.g.
+ ///
+ /// ```ignore
+ /// print!(r"{}", '\r');
+ /// ```
+ Ignore,
+}
- if r.end == contents.len() && c == '\n' && !last_was_cr && !has_internal_newline {
- should_lint = true;
- } else {
- last_was_cr = c == '\r';
- if c == '\n' {
- has_internal_newline = true;
- }
+/// Unescape a normal string into a raw string
+fn conservative_unescape(literal: &str) -> Result<String, UnescapeErr> {
+ let mut unescaped = String::with_capacity(literal.len());
+ let mut chars = literal.chars();
+ let mut err = false;
+
+ while let Some(ch) = chars.next() {
+ match ch {
+ '#' => err = true,
+ '\\' => match chars.next() {
+ Some('\\') => unescaped.push('\\'),
+ Some('"') => err = true,
+ _ => return Err(UnescapeErr::Ignore),
+ },
+ _ => unescaped.push(ch),
}
- };
-
- match fmtstr.style {
- StrStyle::Cooked => unescape::unescape_literal(contents, unescape::Mode::Str, &mut cb),
- StrStyle::Raw(_) => unescape::unescape_literal(contents, unescape::Mode::RawStr, &mut cb),
}
- should_lint
+ if err { Err(UnescapeErr::Lint) } else { Ok(unescaped) }
}
projects / rust.git / blobdiff