bjoernager/rust
bjoernager/rust
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This commit is contained in:
Nathan Whitaker 2020-09-21 16:32:28 -04:00
parent 737bfeffd2
commit 1bcd2452fe
6 changed files with 44 additions and 13 deletions
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19
compiler/rustc_lint/src/methods.rs
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@ -3,10 +3,7 @@ use crate::LateLintPass;
use crate::LintContext;
use rustc_hir::{Expr, ExprKind, PathSegment};
use rustc_middle::ty;
use rustc_span::{
symbol::{sym, Symbol},
ExpnKind, Span,
};
use rustc_span::{symbol::sym, ExpnKind, Span};
declare_lint! {
pub TEMPORARY_CSTRING_AS_PTR,
@ -59,8 +56,6 @@ impl<'tcx> LateLintPass<'tcx> for TemporaryCStringAsPtr {
}
}
const CSTRING_PATH: [Symbol; 4] = [sym::std, sym::ffi, sym::c_str, sym::CString];
fn lint_cstring_as_ptr(
cx: &LateContext<'_>,
as_ptr_span: Span,
@ -68,19 +63,21 @@ fn lint_cstring_as_ptr(
unwrap: &rustc_hir::Expr<'_>,
) {
let source_type = cx.typeck_results().expr_ty(source);
if let ty::Adt(def, substs) = source_type.kind {
if let ty::Adt(def, substs) = source_type.kind() {
if cx.tcx.is_diagnostic_item(sym::result_type, def.did) {
if let ty::Adt(adt, _) = substs.type_at(0).kind {
if cx.match_def_path(adt.did, &CSTRING_PATH) {
if let ty::Adt(adt, _) = substs.type_at(0).kind() {
if cx.tcx.is_diagnostic_item(sym::cstring_type, adt.did) {
cx.struct_span_lint(TEMPORARY_CSTRING_AS_PTR, as_ptr_span, |diag| {
let mut diag = diag
.build("getting the inner pointer of a temporary `CString`");
diag.span_label(as_ptr_span, "this pointer will be invalid");
diag.span_label(
unwrap.span,
"this `CString` is deallocated at the end of the expression, bind it to a variable to extend its lifetime",
"this `CString` is deallocated at the end of the statement, bind it to a variable to extend its lifetime",
);
diag.note("pointers do not have a lifetime; when calling `as_ptr` the `CString` is deallocated because nothing is referencing it as far as the type system is concerned");
diag.note("pointers do not have a lifetime; when calling `as_ptr` the `CString` will be deallocated at the end of the statement...");
diag.note("...because nothing is referencing it as far as the type system is concerned");
diag.help("for more information, see https://doc.rust-lang.org/reference/destructors.html");
diag.emit();
});
}