Remove lint from clippy

Author: nathanwhit

src/tools/clippy/.github/driver.sh

@@ -22,9 +22,9 @@ unset CARGO_MANIFEST_DIR
 
 # Run a lint and make sure it produces the expected output. It's also expected to exit with code 1
 # FIXME: How to match the clippy invocation in compile-test.rs?
-./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/cstring.rs 2> cstring.stderr && exit 1
-sed -e "s,tests/ui,\$DIR," -e "/= help/d" cstring.stderr > normalized.stderr
-diff normalized.stderr tests/ui/cstring.stderr
+./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/cast.rs 2> cast.stderr && exit 1
+sed -e "s,tests/ui,\$DIR," -e "/= help/d" cast.stderr > normalized.stderr
+diff normalized.stderr tests/ui/cast.stderr
 
 
 # make sure "clippy-driver --rustc --arg" and "rustc --arg" behave the same

src/tools/clippy/clippy_lints/src/lib.rs

@@ -707,7 +707,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         &methods::SKIP_WHILE_NEXT,
         &methods::STRING_EXTEND_CHARS,
         &methods::SUSPICIOUS_MAP,
-        &methods::TEMPORARY_CSTRING_AS_PTR,
         &methods::UNINIT_ASSUMED_INIT,
         &methods::UNNECESSARY_FILTER_MAP,
         &methods::UNNECESSARY_FOLD,
@@ -1417,7 +1416,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&methods::SKIP_WHILE_NEXT),
         LintId::of(&methods::STRING_EXTEND_CHARS),
         LintId::of(&methods::SUSPICIOUS_MAP),
-        LintId::of(&methods::TEMPORARY_CSTRING_AS_PTR),
         LintId::of(&methods::UNINIT_ASSUMED_INIT),
         LintId::of(&methods::UNNECESSARY_FILTER_MAP),
         LintId::of(&methods::UNNECESSARY_FOLD),
@@ -1765,7 +1763,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
         LintId::of(&mem_replace::MEM_REPLACE_WITH_UNINIT),
         LintId::of(&methods::CLONE_DOUBLE_REF),
         LintId::of(&methods::ITERATOR_STEP_BY_ZERO),
-        LintId::of(&methods::TEMPORARY_CSTRING_AS_PTR),
         LintId::of(&methods::UNINIT_ASSUMED_INIT),
         LintId::of(&methods::ZST_OFFSET),
         LintId::of(&minmax::MIN_MAX),

src/tools/clippy/clippy_lints/src/methods/mod.rs

@@ -798,40 +798,6 @@ declare_clippy_lint! {
     "using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
 }
 
-declare_clippy_lint! {
-    /// **What it does:** Checks for getting the inner pointer of a temporary
-    /// `CString`.
-    ///
-    /// **Why is this bad?** The inner pointer of a `CString` is only valid as long
-    /// as the `CString` is alive.
-    ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
-    /// ```rust
-    /// # use std::ffi::CString;
-    /// # fn call_some_ffi_func(_: *const i8) {}
-    /// #
-    /// let c_str = CString::new("foo").unwrap().as_ptr();
-    /// unsafe {
-    ///     call_some_ffi_func(c_str);
-    /// }
-    /// ```
-    /// Here `c_str` points to a freed address. The correct use would be:
-    /// ```rust
-    /// # use std::ffi::CString;
-    /// # fn call_some_ffi_func(_: *const i8) {}
-    /// #
-    /// let c_str = CString::new("foo").unwrap();
-    /// unsafe {
-    ///     call_some_ffi_func(c_str.as_ptr());
-    /// }
-    /// ```
-    pub TEMPORARY_CSTRING_AS_PTR,
-    correctness,
-    "getting the inner pointer of a temporary `CString`"
-}
-
 declare_clippy_lint! {
     /// **What it does:** Checks for calling `.step_by(0)` on iterators which panics.
     ///
@@ -1406,7 +1372,6 @@ declare_lint_pass!(Methods => [
     SINGLE_CHAR_PATTERN,
     SINGLE_CHAR_PUSH_STR,
     SEARCH_IS_SOME,
-    TEMPORARY_CSTRING_AS_PTR,
     FILTER_NEXT,
     SKIP_WHILE_NEXT,
     FILTER_MAP,
@@ -1490,7 +1455,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                 lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1])
             },
             ["extend", ..] => lint_extend(cx, expr, arg_lists[0]),
-            ["as_ptr", "unwrap" | "expect"] => lint_cstring_as_ptr(cx, expr, &arg_lists[1][0], &arg_lists[0][0]),
             ["nth", "iter"] => lint_iter_nth(cx, expr, &arg_lists, false),
             ["nth", "iter_mut"] => lint_iter_nth(cx, expr, &arg_lists, true),
             ["nth", ..] => lint_iter_nth_zero(cx, expr, arg_lists[0]),
@@ -2207,26 +2171,6 @@ fn lint_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>
     }
 }
 
-fn lint_cstring_as_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, source: &hir::Expr<'_>, unwrap: &hir::Expr<'_>) {
-    if_chain! {
-        let source_type = cx.typeck_results().expr_ty(source);
-        if let ty::Adt(def, substs) = source_type.kind();
-        if cx.tcx.is_diagnostic_item(sym!(result_type), def.did);
-        if match_type(cx, substs.type_at(0), &paths::CSTRING);
-        then {
-            span_lint_and_then(
-                cx,
-                TEMPORARY_CSTRING_AS_PTR,
-                expr.span,
-                "you are getting the inner pointer of a temporary `CString`",
-                |diag| {
-                    diag.note("that pointer will be invalid outside this expression");
-                    diag.span_help(unwrap.span, "assign the `CString` to a variable to extend its lifetime");
-                });
-        }
-    }
-}
-
 fn lint_iter_cloned_collect<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) {
     if_chain! {
         if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym!(vec_type));

src/tools/clippy/clippy_lints/src/utils/paths.rs

@@ -21,7 +21,6 @@ pub const CLONE_TRAIT_METHOD: [&str; 4] = ["core", "clone", "Clone", "clone"];
 pub const CMP_MAX: [&str; 3] = ["core", "cmp", "max"];
 pub const CMP_MIN: [&str; 3] = ["core", "cmp", "min"];
 pub const COW: [&str; 3] = ["alloc", "borrow", "Cow"];
-pub const CSTRING: [&str; 4] = ["std", "ffi", "c_str", "CString"];
 pub const CSTRING_AS_C_STR: [&str; 5] = ["std", "ffi", "c_str", "CString", "as_c_str"];
 pub const DEFAULT_TRAIT: [&str; 3] = ["core", "default", "Default"];
 pub const DEFAULT_TRAIT_METHOD: [&str; 4] = ["core", "default", "Default", "default"];

src/tools/clippy/src/lintlist/mod.rs

@@ -2258,13 +2258,6 @@ vec![
         deprecation: None,
         module: "temporary_assignment",
     },
-    Lint {
-        name: "temporary_cstring_as_ptr",
-        group: "correctness",
-        desc: "getting the inner pointer of a temporary `CString`",
-        deprecation: None,
-        module: "methods",
-    },
     Lint {
         name: "to_digit_is_some",
         group: "style",