rust/clippy_lints/src/large_include_file.rs
Nicholas Nethercote 6481d37bb9 Add StrStyle to ast::LitKind::ByteStr.
This is required to distinguish between cooked and raw byte string
literals in an `ast::LitKind`, without referring to an adjacent
`token::Lit`. It's a prerequisite for the next commit.
2022-12-02 10:38:58 +11:00

88 lines
2.7 KiB
Rust

use clippy_utils::diagnostics::span_lint_and_note;
use clippy_utils::is_lint_allowed;
use clippy_utils::macros::root_macro_call_first_node;
use rustc_ast::LitKind;
use rustc_hir::Expr;
use rustc_hir::ExprKind;
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::sym;
declare_clippy_lint! {
/// ### What it does
/// Checks for the inclusion of large files via `include_bytes!()`
/// and `include_str!()`
///
/// ### Why is this bad?
/// Including large files can increase the size of the binary
///
/// ### 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 {
#[must_use]
pub fn new(max_file_size: u64) -> Self {
Self { max_file_size }
}
}
impl_lint_pass!(LargeIncludeFile => [LARGE_INCLUDE_FILE]);
impl LateLintPass<'_> for LargeIncludeFile {
fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
if_chain! {
if let Some(macro_call) = root_macro_call_first_node(cx, expr);
if !is_lint_allowed(cx, LARGE_INCLUDE_FILE, expr.hir_id);
if 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);
if let ExprKind::Lit(lit) = &expr.kind;
then {
let len = match &lit.node {
// include_bytes
LitKind::ByteStr(bstr, _) => bstr.len(),
// include_str
LitKind::Str(sym, _) => sym.as_str().len(),
_ => return,
};
if len as u64 <= self.max_file_size {
return;
}
span_lint_and_note(
cx,
LARGE_INCLUDE_FILE,
expr.span,
"attempted to include a large file",
None,
&format!(
"the configuration allows a maximum size of {} bytes",
self.max_file_size
),
);
}
}
}
}