use std::ops::Range;
use crate::utils::{snippet_with_applicability, span_lint, span_lint_and_sugg, span_lint_and_then};
-use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_ast::ast::{Expr, ExprKind, Item, ItemKind, MacCall, StrLit, StrStyle};
+use rustc_ast::token;
+use rustc_ast::tokenstream::TokenStream;
use rustc_errors::Applicability;
use rustc_lexer::unescape::{self, EscapeError};
+use rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_parse::parser;
-use syntax::ast::*;
-use syntax::token;
-use syntax::tokenstream::TokenStream;
-use syntax_pos::{BytePos, Span};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol::Symbol;
+use rustc_span::{BytePos, Span};
declare_clippy_lint! {
/// **What it does:** This lint warns when you use `println!("")` to
///
/// **Example:**
/// ```rust
+ /// // Bad
/// println!("");
+ ///
+ /// // Good
+ /// println!();
/// ```
pub PRINTLN_EMPTY_STRING,
style,
declare_clippy_lint! {
/// **What it does:** This lint warns when you use `print!()` with a format
- /// string that
- /// ends in a newline.
+ /// string that ends in a newline.
///
/// **Why is this bad?** You should use `println!()` instead, which appends the
/// newline.
/// ```rust
/// # use std::fmt::Write;
/// # let mut buf = String::new();
+ ///
+ /// // Bad
/// writeln!(buf, "");
+ ///
+ /// // Good
+ /// writeln!(buf);
/// ```
pub WRITELN_EMPTY_STRING,
style,
/// # use std::fmt::Write;
/// # let mut buf = String::new();
/// # let name = "World";
+ ///
+ /// // Bad
/// write!(buf, "Hello {}!\n", name);
+ ///
+ /// // Good
+ /// writeln!(buf, "Hello {}!", name);
/// ```
pub WRITE_WITH_NEWLINE,
style,
/// ```rust
/// # use std::fmt::Write;
/// # let mut buf = String::new();
+ ///
+ /// // Bad
/// writeln!(buf, "{}", "foo");
+ ///
+ /// // Good
+ /// writeln!(buf, "foo");
/// ```
pub WRITE_LITERAL,
style,
"writing a literal with a format string"
}
-declare_lint_pass!(Write => [
+#[derive(Default)]
+pub struct Write {
+ in_debug_impl: bool,
+}
+
+impl_lint_pass!(Write => [
PRINT_WITH_NEWLINE,
PRINTLN_EMPTY_STRING,
PRINT_STDOUT,
]);
impl EarlyLintPass for Write {
- fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &Mac) {
+ fn check_item(&mut self, _: &EarlyContext<'_>, item: &Item) {
+ if let ItemKind::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;
+ }
+ }
+ }
+
+ fn check_item_post(&mut self, _: &EarlyContext<'_>, _: &Item) {
+ self.in_debug_impl = false;
+ }
+
+ fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &MacCall) {
if mac.path == sym!(println) {
- span_lint(cx, PRINT_STDOUT, mac.span, "use of `println!`");
- if let (Some(fmt_str), _) = check_tts(cx, &mac.tts, false) {
- if fmt_str.contents.is_empty() {
+ span_lint(cx, PRINT_STDOUT, mac.span(), "use of `println!`");
+ if let (Some(fmt_str), _) = self.check_tts(cx, &mac.args.inner_tokens(), false) {
+ if fmt_str.symbol == Symbol::intern("") {
span_lint_and_sugg(
cx,
PRINTLN_EMPTY_STRING,
- mac.span,
+ mac.span(),
"using `println!(\"\")`",
"replace it with",
"println!()".to_string(),
}
}
} else if mac.path == sym!(print) {
- span_lint(cx, PRINT_STDOUT, mac.span, "use of `print!`");
- if let (Some(fmt_str), _) = check_tts(cx, &mac.tts, false) {
- if check_newlines(&fmt_str.contents, fmt_str.style) {
+ span_lint(cx, PRINT_STDOUT, mac.span(), "use of `print!`");
+ if let (Some(fmt_str), _) = self.check_tts(cx, &mac.args.inner_tokens(), false) {
+ if check_newlines(&fmt_str) {
span_lint_and_then(
cx,
PRINT_WITH_NEWLINE,
- mac.span,
+ mac.span(),
"using `print!()` with a format string that ends in a single newline",
|err| {
err.multipart_suggestion(
"use `println!` instead",
vec![
(mac.path.span, String::from("println")),
- (fmt_str.newline_span(), String::new()),
+ (newline_span(&fmt_str), String::new()),
],
Applicability::MachineApplicable,
);
}
}
} else if mac.path == sym!(write) {
- if let (Some(fmt_str), _) = check_tts(cx, &mac.tts, true) {
- if check_newlines(&fmt_str.contents, fmt_str.style) {
+ if let (Some(fmt_str), _) = self.check_tts(cx, &mac.args.inner_tokens(), true) {
+ if check_newlines(&fmt_str) {
span_lint_and_then(
cx,
WRITE_WITH_NEWLINE,
- mac.span,
+ 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")),
- (fmt_str.newline_span(), String::new()),
+ (newline_span(&fmt_str), String::new()),
],
Applicability::MachineApplicable,
);
}
}
} else if mac.path == sym!(writeln) {
- if let (Some(fmt_str), expr) = check_tts(cx, &mac.tts, true) {
- if fmt_str.contents.is_empty() {
+ if let (Some(fmt_str), expr) = self.check_tts(cx, &mac.args.inner_tokens(), true) {
+ if fmt_str.symbol == Symbol::intern("") {
let mut applicability = Applicability::MachineApplicable;
let suggestion = expr.map_or_else(
- move || {
+ || {
applicability = Applicability::HasPlaceholders;
Cow::Borrowed("v")
},
- move |expr| snippet_with_applicability(cx, expr.span, "v", &mut applicability),
+ |e| snippet_with_applicability(cx, e.span, "v", &mut Applicability::MachineApplicable),
);
span_lint_and_sugg(
cx,
WRITELN_EMPTY_STRING,
- mac.span,
+ mac.span(),
format!("using `writeln!({}, \"\")`", suggestion).as_str(),
"replace it with",
format!("writeln!({})", suggestion),
}
}
-/// The arguments of a `print[ln]!` or `write[ln]!` invocation.
-struct FmtStr {
- /// The contents of the format string (inside the quotes).
- contents: String,
- style: StrStyle,
- /// The span of the format string, including quotes, the raw marker, and any raw hashes.
- span: Span,
-}
-
-impl FmtStr {
- /// Given a format string that ends in a newline and its span, calculates the span of the
- /// newline.
- fn newline_span(&self) -> Span {
- let sp = self.span;
-
- let newline_sp_hi = sp.hi()
- - match self.style {
- StrStyle::Cooked => BytePos(1),
- StrStyle::Raw(hashes) => BytePos((1 + hashes).into()),
- };
+/// Given a format string that ends in a newline and its span, calculates the span of the
+/// newline.
+fn newline_span(fmtstr: &StrLit) -> Span {
+ let sp = fmtstr.span;
+ let contents = &fmtstr.symbol.as_str();
- let newline_sp_len = if self.contents.ends_with('\n') {
- BytePos(1)
- } else if self.contents.ends_with(r"\n") {
- BytePos(2)
- } else {
- panic!("expected format string to contain a newline");
+ let newline_sp_hi = sp.hi()
+ - match fmtstr.style {
+ StrStyle::Cooked => BytePos(1),
+ StrStyle::Raw(hashes) => BytePos((1 + hashes).into()),
};
- sp.with_lo(newline_sp_hi - newline_sp_len).with_hi(newline_sp_hi)
- }
-}
+ 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");
+ };
-/// 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))
-/// ```
-#[allow(clippy::too_many_lines)]
-fn check_tts<'a>(cx: &EarlyContext<'a>, tts: &TokenStream, is_write: bool) -> (Option<FmtStr>, Option<Expr>) {
- use fmt_macros::*;
- let tts = tts.clone();
+ sp.with_lo(newline_sp_hi - newline_sp_len).with_hi(newline_sp_hi)
+}
- let mut parser = parser::Parser::new(&cx.sess.parse_sess, tts, None, false, false, None);
- let mut expr: Option<Expr> = None;
- if is_write {
- expr = match parser.parse_expr().map_err(|mut err| err.cancel()) {
- Ok(p) => Some(p.into_inner()),
- Err(_) => return (None, None),
+impl Write {
+ /// 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))
+ /// ```
+ #[allow(clippy::too_many_lines)]
+ fn check_tts<'a>(
+ &self,
+ cx: &EarlyContext<'a>,
+ tts: &TokenStream,
+ is_write: bool,
+ ) -> (Option<StrLit>, Option<Expr>) {
+ use rustc_parse_format::{
+ AlignUnknown, ArgumentImplicitlyIs, ArgumentIs, ArgumentNamed, CountImplied, FormatSpec, ParseMode, Parser,
+ Piece,
};
- // might be `writeln!(foo)`
- if parser.expect(&token::Comma).map_err(|mut err| err.cancel()).is_err() {
- return (None, expr);
- }
- }
+ let tts = tts.clone();
- let (fmtstr, fmtstyle) = match parser.parse_str().map_err(|mut err| err.cancel()) {
- Ok((fmtstr, fmtstyle)) => (fmtstr.to_string(), fmtstyle),
- Err(_) => return (None, expr),
- };
- let fmtspan = parser.prev_span;
- let tmp = fmtstr.clone();
- let mut args = vec![];
- let mut fmt_parser = Parser::new(&tmp, None, Vec::new(), false);
- while let Some(piece) = fmt_parser.next() {
- if !fmt_parser.errors.is_empty() {
- return (None, expr);
- }
- if let Piece::NextArgument(arg) = piece {
- if arg.format.ty == "?" {
- // FIXME: modify rustc's fmt string parser to give us the current span
- span_lint(cx, USE_DEBUG, parser.prev_span, "use of `Debug`-based formatting");
+ let mut parser = parser::Parser::new(&cx.sess.parse_sess, tts, false, None);
+ let mut expr: Option<Expr> = None;
+ if is_write {
+ expr = match parser.parse_expr().map_err(|mut err| err.cancel()) {
+ Ok(p) => Some(p.into_inner()),
+ Err(_) => return (None, None),
+ };
+ // might be `writeln!(foo)`
+ if parser.expect(&token::Comma).map_err(|mut err| err.cancel()).is_err() {
+ return (None, expr);
}
- args.push(arg);
}
- }
- let lint = if is_write { WRITE_LITERAL } else { PRINT_LITERAL };
- let mut idx = 0;
- loop {
- const SIMPLE: FormatSpec<'_> = FormatSpec {
- fill: None,
- align: AlignUnknown,
- flags: 0,
- precision: CountImplied,
- precision_span: None,
- width: CountImplied,
- width_span: None,
- ty: "",
- ty_span: None,
+
+ let fmtstr = match parser.parse_str_lit() {
+ Ok(fmtstr) => fmtstr,
+ Err(_) => return (None, expr),
};
- if !parser.eat(&token::Comma) {
- return (
- Some(FmtStr {
- contents: fmtstr,
- style: fmtstyle,
- span: fmtspan,
- }),
- expr,
- );
+ let tmp = fmtstr.symbol.as_str();
+ let mut args = vec![];
+ let mut fmt_parser = Parser::new(&tmp, None, None, false, ParseMode::Format);
+ while let Some(piece) = fmt_parser.next() {
+ if !fmt_parser.errors.is_empty() {
+ return (None, expr);
+ }
+ if let Piece::NextArgument(arg) = piece {
+ 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, parser.prev_token.span, "use of `Debug`-based formatting");
+ }
+ args.push(arg);
+ }
}
- let token_expr = if let Ok(expr) = parser.parse_expr().map_err(|mut err| err.cancel()) {
- expr
- } else {
- return (
- Some(FmtStr {
- contents: fmtstr,
- style: fmtstyle,
- span: fmtspan,
- }),
- None,
- );
- };
- match &token_expr.kind {
- ExprKind::Lit(_) => {
- let mut all_simple = true;
- let mut seen = false;
- for arg in &args {
- match arg.position {
- ArgumentImplicitlyIs(n) | ArgumentIs(n) => {
- if n == idx {
- all_simple &= arg.format == SIMPLE;
- seen = true;
- }
- },
- ArgumentNamed(_) => {},
+ let lint = if is_write { WRITE_LITERAL } else { PRINT_LITERAL };
+ let mut idx = 0;
+ loop {
+ const SIMPLE: FormatSpec<'_> = FormatSpec {
+ fill: None,
+ align: AlignUnknown,
+ flags: 0,
+ precision: CountImplied,
+ precision_span: None,
+ width: CountImplied,
+ width_span: None,
+ ty: "",
+ ty_span: None,
+ };
+ if !parser.eat(&token::Comma) {
+ return (Some(fmtstr), expr);
+ }
+ let token_expr = if let Ok(expr) = parser.parse_expr().map_err(|mut err| err.cancel()) {
+ expr
+ } else {
+ return (Some(fmtstr), None);
+ };
+ match &token_expr.kind {
+ ExprKind::Lit(_) => {
+ let mut all_simple = true;
+ let mut seen = false;
+ for arg in &args {
+ match arg.position {
+ ArgumentImplicitlyIs(n) | ArgumentIs(n) => {
+ if n == idx {
+ all_simple &= arg.format == SIMPLE;
+ seen = true;
+ }
+ },
+ ArgumentNamed(_) => {},
+ }
}
- }
- if all_simple && seen {
- span_lint(cx, lint, token_expr.span, "literal with an empty format string");
- }
- idx += 1;
- },
- ExprKind::Assign(lhs, rhs) => {
- if let ExprKind::Lit(_) = rhs.kind {
- if let ExprKind::Path(_, p) = &lhs.kind {
- let mut all_simple = true;
- let mut seen = false;
- for arg in &args {
- match arg.position {
- ArgumentImplicitlyIs(_) | ArgumentIs(_) => {},
- ArgumentNamed(name) => {
- if *p == name {
- seen = true;
- all_simple &= arg.format == SIMPLE;
- }
- },
+ if all_simple && seen {
+ span_lint(cx, lint, token_expr.span, "literal with an empty format string");
+ }
+ idx += 1;
+ },
+ ExprKind::Assign(lhs, rhs, _) => {
+ if let ExprKind::Lit(_) = rhs.kind {
+ if let ExprKind::Path(_, p) = &lhs.kind {
+ let mut all_simple = true;
+ let mut seen = false;
+ for arg in &args {
+ match arg.position {
+ ArgumentImplicitlyIs(_) | ArgumentIs(_) => {},
+ ArgumentNamed(name) => {
+ if *p == name {
+ seen = true;
+ all_simple &= arg.format == SIMPLE;
+ }
+ },
+ }
+ }
+ if all_simple && seen {
+ span_lint(cx, lint, rhs.span, "literal with an empty format string");
}
- }
- if all_simple && seen {
- span_lint(cx, lint, rhs.span, "literal with an empty format string");
}
}
- }
- },
- _ => idx += 1,
+ },
+ _ => idx += 1,
+ }
}
}
}
/// Checks if the format string contains a single newline that terminates it.
///
/// Literal and escaped newlines are both checked (only literal for raw strings).
-fn check_newlines(contents: &str, style: StrStyle) -> bool {
+fn check_newlines(fmtstr: &StrLit) -> bool {
let mut has_internal_newline = false;
let mut last_was_cr = false;
let mut should_lint = false;
+ let contents = &fmtstr.symbol.as_str();
+
let mut cb = |r: Range<usize>, c: Result<char, EscapeError>| {
let c = c.unwrap();
}
};
- match style {
- StrStyle::Cooked => unescape::unescape_str(contents, &mut cb),
- StrStyle::Raw(_) => unescape::unescape_raw_str(contents, &mut cb),
+ 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
projects / rust.git / blobdiff