[Clippy] Swap VecArgs::hir to use diagnostic items instead of paths

Author: GnomedDev

clippy_lints/src/slow_vector_initialization.rs

@@ -153,7 +153,7 @@ impl SlowVectorInit {
             && is_expr_path_def_path(cx, func, &paths::VEC_WITH_CAPACITY)
         {
             Some(InitializedSize::Initialized(len_expr))
-        } else if matches!(expr.kind, ExprKind::Call(func, _) if is_expr_path_def_path(cx, func, &paths::VEC_NEW)) {
+        } else if matches!(expr.kind, ExprKind::Call(func, _) if is_path_diagnostic_item(cx, func, sym::vec_new)) {
             Some(InitializedSize::Uninitialized)
         } else {
             None

clippy_utils/src/higher.rs

@@ -4,7 +4,7 @@
 
 use crate::consts::{ConstEvalCtxt, Constant};
 use crate::ty::is_type_diagnostic_item;
-use crate::{is_expn_of, match_def_path, paths};
+use crate::is_expn_of;
 
 use rustc_ast::ast;
 use rustc_hir as hir;
@@ -297,10 +297,10 @@ impl<'a> VecArgs<'a> {
             && is_expn_of(fun.span, "vec").is_some()
             && let Some(fun_def_id) = cx.qpath_res(qpath, fun.hir_id).opt_def_id()
         {
-            return if match_def_path(cx, fun_def_id, &paths::VEC_FROM_ELEM) && args.len() == 2 {
+            return if cx.tcx.is_diagnostic_item(sym::vec_from_elem, fun_def_id) && args.len() == 2 {
                 // `vec![elem; size]` case
                 Some(VecArgs::Repeat(&args[0], &args[1]))
-            } else if match_def_path(cx, fun_def_id, &paths::SLICE_INTO_VEC) && args.len() == 1 {
+            } else if cx.tcx.is_diagnostic_item(sym::slice_into_vec, fun_def_id) && args.len() == 1 {
                 // `vec![a, b, c]` case
                 if let ExprKind::Call(_, [arg]) = &args[0].kind
                     && let ExprKind::Array(args) = arg.kind
@@ -309,7 +309,7 @@ impl<'a> VecArgs<'a> {
                 } else {
                     None
                 }
-            } else if match_def_path(cx, fun_def_id, &paths::VEC_NEW) && args.is_empty() {
+            } else if cx.tcx.is_diagnostic_item(sym::vec_new, fun_def_id) && args.is_empty() {
                 Some(VecArgs::Vec(&[]))
             } else {
                 None

clippy_utils/src/paths.rs

@@ -49,7 +49,6 @@ pub const REGEX_NEW: [&str; 3] = ["regex", "Regex", "new"];
 pub const REGEX_SET_NEW: [&str; 3] = ["regex", "RegexSet", "new"];
 pub const SERDE_DESERIALIZE: [&str; 3] = ["serde", "de", "Deserialize"];
 pub const SERDE_DE_VISITOR: [&str; 3] = ["serde", "de", "Visitor"];
-pub const SLICE_INTO_VEC: [&str; 4] = ["alloc", "slice", "<impl [T]>", "into_vec"];
 pub const STD_IO_SEEK_FROM_CURRENT: [&str; 4] = ["std", "io", "SeekFrom", "Current"];
 pub const STD_IO_SEEKFROM_START: [&str; 4] = ["std", "io", "SeekFrom", "Start"];
 pub const STRING_NEW: [&str; 4] = ["alloc", "string", "String", "new"];
@@ -73,8 +72,6 @@ pub const TOKIO_IO_ASYNCWRITEEXT: [&str; 5] = ["tokio", "io", "util", "async_wri
 pub const TOKIO_IO_OPEN_OPTIONS: [&str; 4] = ["tokio", "fs", "open_options", "OpenOptions"];
 #[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
 pub const TOKIO_IO_OPEN_OPTIONS_NEW: [&str; 5] = ["tokio", "fs", "open_options", "OpenOptions", "new"];
-pub const VEC_FROM_ELEM: [&str; 3] = ["alloc", "vec", "from_elem"];
-pub const VEC_NEW: [&str; 4] = ["alloc", "vec", "Vec", "new"];
 pub const VEC_WITH_CAPACITY: [&str; 4] = ["alloc", "vec", "Vec", "with_capacity"];
 pub const INSTANT_NOW: [&str; 4] = ["std", "time", "Instant", "now"];
 pub const VEC_IS_EMPTY: [&str; 4] = ["alloc", "vec", "Vec", "is_empty"];