rust/clippy_lints/src/large_include_file.rs

85 lines
2.8 KiB
Rust

use clippy_config::Conf;
use clippy_utils::diagnostics::span_lint_and_then;
use clippy_utils::macros::root_macro_call_first_node;
use rustc_ast::LitKind;
use rustc_hir::{Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::impl_lint_pass;
use rustc_span::sym;
declare_clippy_lint! {
/// ### What it does
/// Checks for the inclusion of large files via `include_bytes!()`
/// or `include_str!()`.
///
/// ### Why restrict this?
/// Including large files can undesirably increase the size of the binary produced by the compiler.
/// This lint may be used to catch mistakes where an unexpectedly large file is included, or
/// temporarily to obtain a list of all large files.
///
/// ### Example
/// ```rust,ignore
/// let included_str = include_str!("very_large_file.txt");
/// let included_bytes = include_bytes!("very_large_file.txt");
/// ```
///
/// Use instead:
/// ```rust,ignore
/// use std::fs;
///
/// // You can load the file at runtime
/// let string = fs::read_to_string("very_large_file.txt")?;
/// let bytes = fs::read("very_large_file.txt")?;
/// ```
#[clippy::version = "1.62.0"]
pub LARGE_INCLUDE_FILE,
restriction,
"including a large file"
}
pub struct LargeIncludeFile {
max_file_size: u64,
}
impl LargeIncludeFile {
pub fn new(conf: &'static Conf) -> Self {
Self {
max_file_size: conf.max_include_file_size,
}
}
}
impl_lint_pass!(LargeIncludeFile => [LARGE_INCLUDE_FILE]);
impl LateLintPass<'_> for LargeIncludeFile {
fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
if let ExprKind::Lit(lit) = &expr.kind
&& let len = match &lit.node {
// include_bytes
LitKind::ByteStr(bstr, _) => bstr.len(),
// include_str
LitKind::Str(sym, _) => sym.as_str().len(),
_ => return,
}
&& len as u64 > self.max_file_size
&& let Some(macro_call) = root_macro_call_first_node(cx, expr)
&& (cx.tcx.is_diagnostic_item(sym::include_bytes_macro, macro_call.def_id)
|| cx.tcx.is_diagnostic_item(sym::include_str_macro, macro_call.def_id))
{
#[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
span_lint_and_then(
cx,
LARGE_INCLUDE_FILE,
expr.span.source_callsite(),
"attempted to include a large file",
|diag| {
diag.note(format!(
"the configuration allows a maximum size of {} bytes",
self.max_file_size
));
},
);
}
}
}