rust-clippy/clippy_lints/src/from_str_radix_10.rs

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use clippy_utils::diagnostics::span_lint_and_sugg;
use clippy_utils::sugg::Sugg;
use clippy_utils::ty::is_type_diagnostic_item;
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{def, Expr, ExprKind, PrimTy, QPath, TyKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::Ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::symbol::sym;
declare_clippy_lint! {
/// ### What it does
///
/// Checks for function invocations of the form `primitive::from_str_radix(s, 10)`
///
/// ### Why is this bad?
///
/// This specific common use case can be rewritten as `s.parse::<primitive>()`
/// (and in most cases, the turbofish can be removed), which reduces code length
/// and complexity.
///
/// ### Known problems
///
/// This lint may suggest using (&<expression>).parse() instead of <expression>.parse() directly
/// in some cases, which is correct but adds unnecessary complexity to the code.
///
/// ### Example
/// ```ignore
/// let input: &str = get_input();
/// let num = u16::from_str_radix(input, 10)?;
/// ```
/// Use instead:
/// ```ignore
/// let input: &str = get_input();
/// let num: u16 = input.parse()?;
/// ```
Added `clippy::version` attribute to all normal lints So, some context for this, well, more a story. I'm not used to scripting, I've never really scripted anything, even if it's a valuable skill. I just never really needed it. Now, `@flip1995` correctly suggested using a script for this in `rust-clippy#7813`... And I decided to write a script using nushell because why not? This was a mistake... I spend way more time on this than I would like to admit. It has definitely been more than 4 hours. It shouldn't take that long, but me being new to scripting and nushell just wasn't a good mixture... Anyway, here is the script that creates another script which adds the versions. Fun... Just execute this on the `gh-pages` branch and the resulting `replacer.sh` in `clippy_lints` and it should all work. ```nu mv v0.0.212 rust-1.00.0; mv beta rust-1.57.0; mv master rust-1.58.0; let paths = (open ./rust-1.58.0/lints.json | select id id_span | flatten | select id path); let versions = ( ls | where name =~ "rust-" | select name | format {name}/lints.json | each { open $it | select id | insert version $it | str substring "5,11" version} | group-by id | rotate counter-clockwise id version | update version {get version | first 1} | flatten | select id version); $paths | each { |row| let version = ($versions | where id == ($row.id) | format {version}) let idu = ($row.id | str upcase) $"sed -i '0,/($idu),/{s/pub ($idu),/#[clippy::version = "($version)"]\n pub ($idu),/}' ($row.path)" } | str collect ";" | str find-replace --all '1.00.0' 'pre 1.29.0' | save "replacer.sh"; ``` And this still has some problems, but at this point I just want to be done -.-
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#[clippy::version = "1.52.0"]
pub FROM_STR_RADIX_10,
style,
"from_str_radix with radix 10"
}
declare_lint_pass!(FromStrRadix10 => [FROM_STR_RADIX_10]);
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impl<'tcx> LateLintPass<'tcx> for FromStrRadix10 {
fn check_expr(&mut self, cx: &LateContext<'tcx>, exp: &Expr<'tcx>) {
if_chain! {
if let ExprKind::Call(maybe_path, [src, radix]) = &exp.kind;
if let ExprKind::Path(QPath::TypeRelative(ty, pathseg)) = &maybe_path.kind;
// check if the first part of the path is some integer primitive
if let TyKind::Path(ty_qpath) = &ty.kind;
let ty_res = cx.qpath_res(ty_qpath, ty.hir_id);
if let def::Res::PrimTy(prim_ty) = ty_res;
if matches!(prim_ty, PrimTy::Int(_) | PrimTy::Uint(_));
// check if the second part of the path indeed calls the associated
// function `from_str_radix`
if pathseg.ident.name.as_str() == "from_str_radix";
// check if the second argument is a primitive `10`
if let ExprKind::Lit(lit) = &radix.kind;
if let rustc_ast::ast::LitKind::Int(10, _) = lit.node;
then {
let expr = if let ExprKind::AddrOf(_, _, expr) = &src.kind {
let ty = cx.typeck_results().expr_ty(expr);
if is_ty_stringish(cx, ty) {
expr
} else {
&src
}
} else {
&src
};
let sugg = Sugg::hir_with_applicability(
cx,
expr,
"<string>",
&mut Applicability::MachineApplicable
).maybe_par();
span_lint_and_sugg(
cx,
FROM_STR_RADIX_10,
exp.span,
"this call to `from_str_radix` can be replaced with a call to `str::parse`",
"try",
format!("{}.parse::<{}>()", sugg, prim_ty.name_str()),
Applicability::MaybeIncorrect
);
}
}
}
}
/// Checks if a Ty is `String` or `&str`
fn is_ty_stringish(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
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is_type_diagnostic_item(cx, ty, sym::String) || is_type_diagnostic_item(cx, ty, sym::str)
}