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use std::str::Utf8Error;
use rustc_ast::{BorrowKind, LitKind};
use rustc_hir::{Expr, ExprKind};
use rustc_span::source_map::Spanned;
use rustc_span::sym;
use crate::lints::InvalidFromUtf8Diag;
use crate::{LateContext, LateLintPass, LintContext};
declare_lint! {
/// The `invalid_from_utf8_unchecked` lint checks for calls to
/// `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`
/// with an invalid UTF-8 literal.
///
/// ### Example
///
/// ```rust,compile_fail
/// # #[allow(unused)]
/// unsafe {
/// std::str::from_utf8_unchecked(b"Ru\x82st");
/// }
/// ```
///
/// {{produces}}
///
/// ### Explanation
///
/// Creating such a `str` would result in undefined behavior as per documentation
/// for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.
pub INVALID_FROM_UTF8_UNCHECKED,
Deny,
"using a non UTF-8 literal in `std::str::from_utf8_unchecked`"
}
declare_lint! {
/// The `invalid_from_utf8` lint checks for calls to
/// `std::str::from_utf8` and `std::str::from_utf8_mut`
/// with an invalid UTF-8 literal.
///
/// ### Example
///
/// ```rust
/// # #[allow(unused)]
/// std::str::from_utf8(b"Ru\x82st");
/// ```
///
/// {{produces}}
///
/// ### Explanation
///
/// Trying to create such a `str` would always return an error as per documentation
/// for `std::str::from_utf8` and `std::str::from_utf8_mut`.
pub INVALID_FROM_UTF8,
Warn,
"using a non UTF-8 literal in `std::str::from_utf8`"
}
declare_lint_pass!(InvalidFromUtf8 => [INVALID_FROM_UTF8_UNCHECKED, INVALID_FROM_UTF8]);
impl<'tcx> LateLintPass<'tcx> for InvalidFromUtf8 {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
if let ExprKind::Call(path, [arg]) = expr.kind
&& let ExprKind::Path(ref qpath) = path.kind
&& let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
&& let Some(diag_item) = cx.tcx.get_diagnostic_name(def_id)
&& [sym::str_from_utf8, sym::str_from_utf8_mut,
sym::str_from_utf8_unchecked, sym::str_from_utf8_unchecked_mut].contains(&diag_item)
{
let lint = |utf8_error: Utf8Error| {
let label = arg.span;
let method = diag_item.as_str().strip_prefix("str_").unwrap();
let method = format!("std::str::{method}");
let valid_up_to = utf8_error.valid_up_to();
let is_unchecked_variant = diag_item.as_str().contains("unchecked");
cx.emit_spanned_lint(
if is_unchecked_variant { INVALID_FROM_UTF8_UNCHECKED } else { INVALID_FROM_UTF8 },
expr.span,
if is_unchecked_variant {
InvalidFromUtf8Diag::Unchecked { method, valid_up_to, label }
} else {
InvalidFromUtf8Diag::Checked { method, valid_up_to, label }
}
)
};
match &arg.kind {
ExprKind::Lit(Spanned { node: lit, .. }) => {
if let LitKind::ByteStr(bytes, _) = &lit
&& let Err(utf8_error) = std::str::from_utf8(bytes)
{
lint(utf8_error);
}
},
ExprKind::AddrOf(BorrowKind::Ref, _, Expr { kind: ExprKind::Array(args), .. }) => {
let elements = args.iter().map(|e|{
match &e.kind {
ExprKind::Lit(Spanned { node: lit, .. }) => match lit {
LitKind::Byte(b) => Some(*b),
LitKind::Int(b, _) => Some(*b as u8),
_ => None
}
_ => None
}
}).collect::<Option<Vec<_>>>();
if let Some(elements) = elements
&& let Err(utf8_error) = std::str::from_utf8(&elements)
{
lint(utf8_error);
}
}
_ => {}
}
}
}
}
|
