New lint: `dangling_pointers_from_temporaries`

1 files changed, 0 insertions, 69 deletions

diff --git a/compiler/rustc_lint/src/methods.rs b/compiler/rustc_lint/src/methods.rs
deleted file mode 100644
index df22bf0972d..00000000000
--- a/compiler/rustc_lint/src/methods.rs
+++ /dev/null
@@ -1,69 +0,0 @@
-use rustc_hir::{Expr, ExprKind};
-use rustc_middle::ty;
-use rustc_session::{declare_lint, declare_lint_pass};
-use rustc_span::Span;
-use rustc_span::symbol::sym;
-
-use crate::lints::CStringPtr;
-use crate::{LateContext, LateLintPass, LintContext};
-
-declare_lint! {
-    /// The `temporary_cstring_as_ptr` lint detects getting the inner pointer of
-    /// a temporary `CString`.
-    ///
-    /// ### Example
-    ///
-    /// ```rust
-    /// # #![allow(unused)]
-    /// # use std::ffi::CString;
-    /// let c_str = CString::new("foo").unwrap().as_ptr();
-    /// ```
-    ///
-    /// {{produces}}
-    ///
-    /// ### Explanation
-    ///
-    /// The inner pointer of a `CString` lives only as long as the `CString` it
-    /// points to. Getting the inner pointer of a *temporary* `CString` allows the `CString`
-    /// to be dropped at the end of the statement, as it is not being referenced as far as the
-    /// typesystem is concerned. This means outside of the statement the pointer will point to
-    /// freed memory, which causes undefined behavior if the pointer is later dereferenced.
-    pub TEMPORARY_CSTRING_AS_PTR,
-    Warn,
-    "detects getting the inner pointer of a temporary `CString`"
-}
-
-declare_lint_pass!(TemporaryCStringAsPtr => [TEMPORARY_CSTRING_AS_PTR]);
-
-impl<'tcx> LateLintPass<'tcx> for TemporaryCStringAsPtr {
-    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if let ExprKind::MethodCall(as_ptr_path, as_ptr_receiver, ..) = expr.kind
-            && as_ptr_path.ident.name == sym::as_ptr
-            && let ExprKind::MethodCall(unwrap_path, unwrap_receiver, ..) = as_ptr_receiver.kind
-            && (unwrap_path.ident.name == sym::unwrap || unwrap_path.ident.name == sym::expect)
-        {
-            lint_cstring_as_ptr(cx, as_ptr_path.ident.span, unwrap_receiver, as_ptr_receiver);
-        }
-    }
-}
-
-fn lint_cstring_as_ptr(
-    cx: &LateContext<'_>,
-    as_ptr_span: Span,
-    source: &rustc_hir::Expr<'_>,
-    unwrap: &rustc_hir::Expr<'_>,
-) {
-    let source_type = cx.typeck_results().expr_ty(source);
-    if let ty::Adt(def, args) = source_type.kind() {
-        if cx.tcx.is_diagnostic_item(sym::Result, def.did()) {
-            if let ty::Adt(adt, _) = args.type_at(0).kind() {
-                if cx.tcx.is_diagnostic_item(sym::cstring_type, adt.did()) {
-                    cx.emit_span_lint(TEMPORARY_CSTRING_AS_PTR, as_ptr_span, CStringPtr {
-                        as_ptr: as_ptr_span,
-                        unwrap: unwrap.span,
-                    });
-                }
-            }
-        }
-    }
-}