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-rw-r--r--src/tools/clippy/clippy_lints/src/write.rs145
1 files changed, 133 insertions, 12 deletions
diff --git a/src/tools/clippy/clippy_lints/src/write.rs b/src/tools/clippy/clippy_lints/src/write.rs
index 32718200c..640a09a7a 100644
--- a/src/tools/clippy/clippy_lints/src/write.rs
+++ b/src/tools/clippy/clippy_lints/src/write.rs
@@ -3,8 +3,9 @@ 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 clippy_utils::source::{snippet, snippet_opt, snippet_with_applicability};
use rustc_ast::ast::{Expr, ExprKind, Impl, Item, ItemKind, MacCall, Path, StrLit, StrStyle};
+use rustc_ast::ptr::P;
use rustc_ast::token::{self, LitKind};
use rustc_ast::tokenstream::TokenStream;
use rustc_errors::{Applicability, DiagnosticBuilder};
@@ -256,6 +257,28 @@ declare_clippy_lint! {
"writing a literal with a format string"
}
+declare_clippy_lint! {
+ /// ### What it does
+ /// This lint warns when a named parameter in a format string is used as a positional one.
+ ///
+ /// ### Why is this bad?
+ /// It may be confused for an assignment and obfuscates which parameter is being used.
+ ///
+ /// ### Example
+ /// ```rust
+ /// println!("{}", x = 10);
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// println!("{x}", x = 10);
+ /// ```
+ #[clippy::version = "1.63.0"]
+ pub POSITIONAL_NAMED_FORMAT_PARAMETERS,
+ suspicious,
+ "named parameter in a format string is used positionally"
+}
+
#[derive(Default)]
pub struct Write {
in_debug_impl: bool,
@@ -270,7 +293,8 @@ impl_lint_pass!(Write => [
PRINT_LITERAL,
WRITE_WITH_NEWLINE,
WRITELN_EMPTY_STRING,
- WRITE_LITERAL
+ WRITE_LITERAL,
+ POSITIONAL_NAMED_FORMAT_PARAMETERS,
]);
impl EarlyLintPass for Write {
@@ -408,6 +432,7 @@ fn newline_span(fmtstr: &StrLit) -> (Span, bool) {
#[derive(Default)]
struct SimpleFormatArgs {
unnamed: Vec<Vec<Span>>,
+ complex_unnamed: Vec<Vec<Span>>,
named: Vec<(Symbol, Vec<Span>)>,
}
impl SimpleFormatArgs {
@@ -419,6 +444,10 @@ impl SimpleFormatArgs {
})
}
+ fn get_complex_unnamed(&self) -> impl Iterator<Item = &[Span]> {
+ self.complex_unnamed.iter().map(Vec::as_slice)
+ }
+
fn get_named(&self, n: &Path) -> &[Span] {
self.named.iter().find(|x| *n == x.0).map_or(&[], |x| x.1.as_slice())
}
@@ -479,6 +508,61 @@ impl SimpleFormatArgs {
},
};
}
+
+ fn push_to_complex(&mut self, span: Span, position: usize) {
+ if self.complex_unnamed.len() <= position {
+ self.complex_unnamed.resize_with(position, Vec::new);
+ self.complex_unnamed.push(vec![span]);
+ } else {
+ let args: &mut Vec<Span> = &mut self.complex_unnamed[position];
+ args.push(span);
+ }
+ }
+
+ fn push_complex(
+ &mut self,
+ cx: &EarlyContext<'_>,
+ arg: rustc_parse_format::Argument<'_>,
+ str_lit_span: Span,
+ fmt_span: Span,
+ ) {
+ use rustc_parse_format::{ArgumentImplicitlyIs, ArgumentIs, CountIsParam, CountIsStar};
+
+ let snippet = snippet_opt(cx, fmt_span);
+
+ let end = snippet
+ .as_ref()
+ .and_then(|s| s.find(':'))
+ .or_else(|| fmt_span.hi().0.checked_sub(fmt_span.lo().0 + 1).map(|u| u as usize));
+
+ if let (ArgumentIs(n) | ArgumentImplicitlyIs(n), Some(end)) = (arg.position, end) {
+ let span = fmt_span.from_inner(InnerSpan::new(1, end));
+ self.push_to_complex(span, n);
+ };
+
+ if let (CountIsParam(n) | CountIsStar(n), Some(span)) = (arg.format.precision, arg.format.precision_span) {
+ // We need to do this hack as precision spans should be converted from .* to .foo$
+ let hack = if snippet.as_ref().and_then(|s| s.find('*')).is_some() {
+ 0
+ } else {
+ 1
+ };
+
+ let span = str_lit_span.from_inner(InnerSpan {
+ start: span.start + 1,
+ end: span.end - hack,
+ });
+ self.push_to_complex(span, n);
+ };
+
+ if let (CountIsParam(n), Some(span)) = (arg.format.width, arg.format.width_span) {
+ let span = str_lit_span.from_inner(InnerSpan {
+ start: span.start,
+ end: span.end - 1,
+ });
+ self.push_to_complex(span, n);
+ };
+ }
}
impl Write {
@@ -511,8 +595,8 @@ impl Write {
// 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);
+ args.push_complex(cx, arg, str_lit.span, span);
}
parser.errors.is_empty().then_some(args)
@@ -566,6 +650,7 @@ impl Write {
let lint = if is_write { WRITE_LITERAL } else { PRINT_LITERAL };
let mut unnamed_args = args.get_unnamed();
+ let mut complex_unnamed_args = args.get_complex_unnamed();
loop {
if !parser.eat(&token::Comma) {
return (Some(fmtstr), expr);
@@ -577,11 +662,20 @@ impl Write {
} else {
return (Some(fmtstr), None);
};
+ let complex_unnamed_arg = complex_unnamed_args.next();
+
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,
+ ExprKind::Assign(lhs, rhs, _) => {
+ if let Some(span) = complex_unnamed_arg {
+ for x in span {
+ Self::report_positional_named_param(cx, *x, lhs, rhs);
+ }
+ }
+ match (&lhs.kind, &rhs.kind) {
+ (ExprKind::Path(_, p), ExprKind::Lit(lit)) => (args.get_named(p), lit),
+ _ => continue,
+ }
},
_ => {
unnamed_args.next();
@@ -589,12 +683,12 @@ impl Write {
},
};
- let replacement: String = match lit.token.kind {
+ let replacement: String = match lit.token_lit.kind {
LitKind::StrRaw(_) | LitKind::ByteStrRaw(_) if matches!(fmtstr.style, StrStyle::Raw(_)) => {
- lit.token.symbol.as_str().replace('{', "{{").replace('}', "}}")
+ lit.token_lit.symbol.as_str().replace('{', "{{").replace('}', "}}")
},
LitKind::Str | LitKind::ByteStr if matches!(fmtstr.style, StrStyle::Cooked) => {
- lit.token.symbol.as_str().replace('{', "{{").replace('}', "}}")
+ lit.token_lit.symbol.as_str().replace('{', "{{").replace('}', "}}")
},
LitKind::StrRaw(_)
| LitKind::Str
@@ -603,7 +697,7 @@ impl Write {
| LitKind::Integer
| LitKind::Float
| LitKind::Err => continue,
- LitKind::Byte | LitKind::Char => match lit.token.symbol.as_str() {
+ LitKind::Byte | LitKind::Char => match lit.token_lit.symbol.as_str() {
"\"" if matches!(fmtstr.style, StrStyle::Cooked) => "\\\"",
"\"" if matches!(fmtstr.style, StrStyle::Raw(0)) => continue,
"\\\\" if matches!(fmtstr.style, StrStyle::Raw(_)) => "\\",
@@ -614,7 +708,7 @@ impl Write {
x => x,
}
.into(),
- LitKind::Bool => lit.token.symbol.as_str().deref().into(),
+ LitKind::Bool => lit.token_lit.symbol.as_str().deref().into(),
};
if !fmt_spans.is_empty() {
@@ -637,6 +731,29 @@ impl Write {
}
}
+ fn report_positional_named_param(cx: &EarlyContext<'_>, span: Span, lhs: &P<Expr>, _rhs: &P<Expr>) {
+ if let ExprKind::Path(_, _p) = &lhs.kind {
+ let mut applicability = Applicability::MachineApplicable;
+ let name = snippet_with_applicability(cx, lhs.span, "name", &mut applicability);
+ // We need to do this hack as precision spans should be converted from .* to .foo$
+ let hack = snippet(cx, span, "").contains('*');
+
+ span_lint_and_sugg(
+ cx,
+ POSITIONAL_NAMED_FORMAT_PARAMETERS,
+ span,
+ &format!("named parameter {} is used as a positional parameter", name),
+ "replace it with",
+ if hack {
+ format!("{}$", name)
+ } else {
+ format!("{}", name)
+ },
+ applicability,
+ );
+ };
+ }
+
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 {
@@ -688,7 +805,11 @@ fn check_newlines(fmtstr: &StrLit) -> bool {
let contents = fmtstr.symbol.as_str();
let mut cb = |r: Range<usize>, c: Result<char, EscapeError>| {
- let c = c.unwrap();
+ let c = match c {
+ Ok(c) => c,
+ Err(e) if !e.is_fatal() => return,
+ Err(e) => panic!("{:?}", e),
+ };
if r.end == contents.len() && c == '\n' && !last_was_cr && !has_internal_newline {
should_lint = true;
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-18 16:13:26 +0000