86 lines
3.2 KiB
Rust
86 lines
3.2 KiB
Rust
|
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::InvalidFromUtf8UncheckedDiag;
|
||
|
|
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_pass!(InvalidFromUtf8 => [INVALID_FROM_UTF8_UNCHECKED]);
|
||
|
|
|
||
|
|
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_unchecked, sym::str_from_utf8_unchecked_mut].contains(&diag_item)
|
||
|
|
{
|
||
|
|
let lint = |utf8_error: Utf8Error| {
|
||
|
|
let method = diag_item.as_str().strip_prefix("str_").unwrap();
|
||
|
|
cx.emit_spanned_lint(INVALID_FROM_UTF8_UNCHECKED, expr.span, InvalidFromUtf8UncheckedDiag {
|
||
|
|
method: format!("std::str::{method}"),
|
||
|
|
valid_up_to: utf8_error.valid_up_to(),
|
||
|
|
label: arg.span,
|
||
|
|
})
|
||
|
|
};
|
||
|
|
|
||
|
|
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);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
_ => {}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|