Rollup merge of #108801 - fee1-dead-contrib:c-str, r=compiler-errors

Implement RFC 3348, `c"foo"` literals

RFC: rust-lang/rfcs#3348
Tracking issue: #105723

Author: Dylan-DPC

clippy_lints/src/matches/match_same_arms.rs

@@ -284,6 +284,7 @@ impl<'a> NormalizedPat<'a> {
                     LitKind::Str(sym, _) => Self::LitStr(sym),
                     LitKind::ByteStr(ref bytes, _) => Self::LitBytes(bytes),
                     LitKind::Byte(val) => Self::LitInt(val.into()),
+                    LitKind::CStr(ref bytes, _) => Self::LitBytes(bytes),
                     LitKind::Char(val) => Self::LitInt(val.into()),
                     LitKind::Int(val, _) => Self::LitInt(val),
                     LitKind::Bool(val) => Self::LitBool(val),

clippy_lints/src/strlen_on_c_strings.rs

@@ -1,11 +1,11 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_with_context;
-use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item};
 use clippy_utils::visitors::is_expr_unsafe;
 use clippy_utils::{get_parent_node, match_libc_symbol};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::{Block, BlockCheckMode, Expr, ExprKind, Node, UnsafeSource};
+use rustc_hir::{Block, BlockCheckMode, Expr, ExprKind, LangItem, Node, UnsafeSource};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::sym;
@@ -67,7 +67,7 @@ impl<'tcx> LateLintPass<'tcx> for StrlenOnCStrings {
                 let val_name = snippet_with_context(cx, self_arg.span, ctxt, "..", &mut app).0;
                 let method_name = if is_type_diagnostic_item(cx, ty, sym::cstring_type) {
                     "as_bytes"
-                } else if is_type_diagnostic_item(cx, ty, sym::CStr) {
+                } else if is_type_lang_item(cx, ty, LangItem::CStr) {
                     "to_bytes"
                 } else {
                     return;

clippy_lints/src/utils/author.rs

@@ -304,6 +304,11 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
                 kind!("ByteStr(ref {vec})");
                 chain!(self, "let [{:?}] = **{vec}", vec.value);
             },
+            LitKind::CStr(ref vec, _) => {
+                bind!(self, vec);
+                kind!("CStr(ref {vec})");
+                chain!(self, "let [{:?}] = **{vec}", vec.value);
+            }
             LitKind::Str(s, _) => {
                 bind!(self, s);
                 kind!("Str({s}, _)");

clippy_utils/src/consts.rs

@@ -211,6 +211,7 @@ pub fn lit_to_mir_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
         LitKind::Str(ref is, _) => Constant::Str(is.to_string()),
         LitKind::Byte(b) => Constant::Int(u128::from(b)),
         LitKind::ByteStr(ref s, _) => Constant::Binary(Lrc::clone(s)),
+        LitKind::CStr(ref s, _) => Constant::Binary(Lrc::clone(s)),
         LitKind::Char(c) => Constant::Char(c),
         LitKind::Int(n, _) => Constant::Int(n),
         LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {