Auto merge of #8474 - Alexendoo:paths, r=Manishearth

Replace some more paths with diagnostic items

cc #5393

Replaces the macro & mem paths, and catches a couple others that were unused

changelog: none

clippy_lints/src/drop_forget_ref.rs

@@ -1,11 +1,11 @@
 use clippy_utils::diagnostics::span_lint_and_note;
 use clippy_utils::ty::is_copy;
-use clippy_utils::{match_def_path, paths};
 use if_chain::if_chain;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -128,14 +128,16 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetRef {
                 let arg_ty = cx.typeck_results().expr_ty(arg);
 
                 if let ty::Ref(..) = arg_ty.kind() {
-                    if match_def_path(cx, def_id, &paths::DROP) {
-                        lint = DROP_REF;
-                        msg = DROP_REF_SUMMARY.to_string();
-                    } else if match_def_path(cx, def_id, &paths::MEM_FORGET) {
-                        lint = FORGET_REF;
-                        msg = FORGET_REF_SUMMARY.to_string();
-                    } else {
-                        return;
+                    match cx.tcx.get_diagnostic_name(def_id) {
+                        Some(sym::mem_drop) => {
+                            lint = DROP_REF;
+                            msg = DROP_REF_SUMMARY.to_string();
+                        },
+                        Some(sym::mem_forget) => {
+                            lint = FORGET_REF;
+                            msg = FORGET_REF_SUMMARY.to_string();
+                        },
+                        _ => return,
                     }
                     span_lint_and_note(cx,
                                        lint,
@@ -144,14 +146,16 @@ impl<'tcx> LateLintPass<'tcx> for DropForgetRef {
                                        Some(arg.span),
                                        &format!("argument has type `{}`", arg_ty));
                 } else if is_copy(cx, arg_ty) {
-                    if match_def_path(cx, def_id, &paths::DROP) {
-                        lint = DROP_COPY;
-                        msg = DROP_COPY_SUMMARY.to_string();
-                    } else if match_def_path(cx, def_id, &paths::MEM_FORGET) {
-                        lint = FORGET_COPY;
-                        msg = FORGET_COPY_SUMMARY.to_string();
-                    } else {
-                        return;
+                    match cx.tcx.get_diagnostic_name(def_id) {
+                        Some(sym::mem_drop) => {
+                            lint = DROP_COPY;
+                            msg = DROP_COPY_SUMMARY.to_string();
+                        },
+                        Some(sym::mem_forget) => {
+                            lint = FORGET_COPY;
+                            msg = FORGET_COPY_SUMMARY.to_string();
+                        },
+                        _ => return,
                     }
                     span_lint_and_note(cx,
                                        lint,

clippy_lints/src/manual_bits.rs

@@ -1,13 +1,14 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::source::snippet_opt;
-use clippy_utils::{match_def_path, meets_msrv, msrvs, paths};
+use clippy_utils::{meets_msrv, msrvs};
 use rustc_ast::ast::LitKind;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, Expr, ExprKind, GenericArg, QPath};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, Ty};
 use rustc_semver::RustcVersion;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -99,7 +100,7 @@ fn get_size_of_ty<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<
         if let Some(GenericArg::Type(real_ty)) = args.args.get(0);
 
         if let Some(def_id) = cx.qpath_res(count_func_qpath, count_func.hir_id).opt_def_id();
-        if match_def_path(cx, def_id, &paths::MEM_SIZE_OF);
+        if cx.tcx.is_diagnostic_item(sym::mem_size_of, def_id);
         then {
             cx.typeck_results().node_substs(count_func.hir_id).types().next().map(|resolved_ty| (real_ty, resolved_ty))
         } else {

clippy_lints/src/mem_forget.rs

@@ -1,8 +1,8 @@
 use clippy_utils::diagnostics::span_lint;
-use clippy_utils::{match_def_path, paths};
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -32,7 +32,7 @@ impl<'tcx> LateLintPass<'tcx> for MemForget {
         if let ExprKind::Call(path_expr, [ref first_arg, ..]) = e.kind {
             if let ExprKind::Path(ref qpath) = path_expr.kind {
                 if let Some(def_id) = cx.qpath_res(qpath, path_expr.hir_id).opt_def_id() {
-                    if match_def_path(cx, def_id, &paths::MEM_FORGET) {
+                    if cx.tcx.is_diagnostic_item(sym::mem_forget, def_id) {
                         let forgot_ty = cx.typeck_results().expr_ty(first_arg);
 
                         if forgot_ty.ty_adt_def().map_or(false, |def| def.has_dtor(cx.tcx)) {

clippy_lints/src/mem_replace.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::source::{snippet, snippet_with_applicability};
 use clippy_utils::ty::is_non_aggregate_primitive_type;
-use clippy_utils::{is_default_equivalent, is_lang_ctor, match_def_path, meets_msrv, msrvs, paths};
+use clippy_utils::{is_default_equivalent, is_lang_ctor, meets_msrv, msrvs};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::OptionNone;
@@ -249,7 +249,7 @@ impl<'tcx> LateLintPass<'tcx> for MemReplace {
             if let ExprKind::Call(func, func_args) = expr.kind;
             if let ExprKind::Path(ref func_qpath) = func.kind;
             if let Some(def_id) = cx.qpath_res(func_qpath, func.hir_id).opt_def_id();
-            if match_def_path(cx, def_id, &paths::MEM_REPLACE);
+            if cx.tcx.is_diagnostic_item(sym::mem_replace, def_id);
             if let [dest, src] = func_args;
             then {
                 check_replace_option_with_none(cx, src, dest, expr.span);

clippy_lints/src/methods/uninit_assumed_init.rs

@@ -1,8 +1,9 @@
 use clippy_utils::diagnostics::span_lint;
-use clippy_utils::{is_expr_path_def_path, paths, ty::is_uninit_value_valid_for_ty};
+use clippy_utils::{is_expr_diagnostic_item, ty::is_uninit_value_valid_for_ty};
 use if_chain::if_chain;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
+use rustc_span::sym;
 
 use super::UNINIT_ASSUMED_INIT;
 
@@ -11,7 +12,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr
     if_chain! {
         if let hir::ExprKind::Call(callee, args) = recv.kind;
         if args.is_empty();
-        if is_expr_path_def_path(cx, callee, &paths::MEM_MAYBEUNINIT_UNINIT);
+        if is_expr_diagnostic_item(cx, callee, sym::maybe_uninit_uninit);
         if !is_uninit_value_valid_for_ty(cx, cx.typeck_results().expr_ty_adjusted(expr));
         then {
             span_lint(

clippy_lints/src/redundant_clone.rs

@@ -135,7 +135,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClone {
             }
 
             if let ty::Adt(def, _) = arg_ty.kind() {
-                if match_def_path(cx, def.did, &paths::MEM_MANUALLY_DROP) {
+                if def.is_manually_drop() {
                     continue;
                 }
             }

clippy_lints/src/size_of_in_element_count.rs

@@ -9,6 +9,7 @@ use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, Ty, TypeAndMut};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -44,8 +45,7 @@ fn get_size_of_ty<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, inverted:
                 if !inverted;
                 if let ExprKind::Path(ref count_func_qpath) = count_func.kind;
                 if let Some(def_id) = cx.qpath_res(count_func_qpath, count_func.hir_id).opt_def_id();
-                if match_def_path(cx, def_id, &paths::MEM_SIZE_OF)
-                    || match_def_path(cx, def_id, &paths::MEM_SIZE_OF_VAL);
+                if matches!(cx.tcx.get_diagnostic_name(def_id), Some(sym::mem_size_of | sym::mem_size_of_val));
                 then {
                     cx.typeck_results().node_substs(count_func.hir_id).types().next()
                 } else {

clippy_lints/src/undropped_manually_drops.rs

@@ -1,9 +1,10 @@
 use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::path_res;
 use clippy_utils::ty::is_type_lang_item;
-use clippy_utils::{match_function_call, paths};
-use rustc_hir::{lang_items, Expr};
+use rustc_hir::{lang_items, Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -38,9 +39,12 @@ declare_lint_pass!(UndroppedManuallyDrops => [UNDROPPED_MANUALLY_DROPS]);
 
 impl<'tcx> LateLintPass<'tcx> for UndroppedManuallyDrops {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if let Some([arg_0, ..]) = match_function_call(cx, expr, &paths::DROP) {
+        if_chain! {
+            if let ExprKind::Call(fun, [arg_0, ..]) = expr.kind;
+            if path_res(cx, fun).opt_def_id() == cx.tcx.get_diagnostic_item(sym::mem_drop);
             let ty = cx.typeck_results().expr_ty(arg_0);
-            if is_type_lang_item(cx, ty, lang_items::LangItem::ManuallyDrop) {
+            if is_type_lang_item(cx, ty, lang_items::LangItem::ManuallyDrop);
+            then {
                 span_lint_and_help(
                     cx,
                     UNDROPPED_MANUALLY_DROPS,

clippy_utils/src/macros.rs

@@ -1,7 +1,6 @@
 #![allow(clippy::similar_names)] // `expr` and `expn`
 
 use crate::visitors::expr_visitor_no_bodies;
-use crate::{match_def_path, paths};
 
 use arrayvec::ArrayVec;
 use if_chain::if_chain;
@@ -14,29 +13,31 @@ use rustc_span::hygiene::{self, MacroKind, SyntaxContext};
 use rustc_span::{sym, ExpnData, ExpnId, ExpnKind, Span, Symbol};
 use std::ops::ControlFlow;
 
-const FORMAT_MACRO_PATHS: &[&[&str]] = &[
-    &paths::FORMAT_ARGS_MACRO,
-    &paths::ASSERT_EQ_MACRO,
-    &paths::ASSERT_MACRO,
-    &paths::ASSERT_NE_MACRO,
-    &paths::EPRINT_MACRO,
-    &paths::EPRINTLN_MACRO,
-    &paths::PRINT_MACRO,
-    &paths::PRINTLN_MACRO,
-    &paths::WRITE_MACRO,
-    &paths::WRITELN_MACRO,
+const FORMAT_MACRO_DIAG_ITEMS: &[Symbol] = &[
+    sym::assert_eq_macro,
+    sym::assert_macro,
+    sym::assert_ne_macro,
+    sym::debug_assert_eq_macro,
+    sym::debug_assert_macro,
+    sym::debug_assert_ne_macro,
+    sym::eprint_macro,
+    sym::eprintln_macro,
+    sym::format_args_macro,
+    sym::format_macro,
+    sym::print_macro,
+    sym::println_macro,
+    sym::std_panic_macro,
+    sym::write_macro,
+    sym::writeln_macro,
 ];
 
-const FORMAT_MACRO_DIAG_ITEMS: &[Symbol] = &[sym::format_macro, sym::std_panic_macro];
-
 /// Returns true if a given Macro `DefId` is a format macro (e.g. `println!`)
 pub fn is_format_macro(cx: &LateContext<'_>, macro_def_id: DefId) -> bool {
-    FORMAT_MACRO_PATHS
-        .iter()
-        .any(|path| match_def_path(cx, macro_def_id, path))
-        || FORMAT_MACRO_DIAG_ITEMS
-            .iter()
-            .any(|diag_item| cx.tcx.is_diagnostic_item(*diag_item, macro_def_id))
+    if let Some(name) = cx.tcx.get_diagnostic_name(macro_def_id) {
+        FORMAT_MACRO_DIAG_ITEMS.contains(&name)
+    } else {
+        false
+    }
 }
 
 /// A macro call, like `vec![1, 2, 3]`.

clippy_utils/src/paths.rs

@@ -16,44 +16,27 @@ pub const APPLICABILITY_VALUES: [[&str; 3]; 4] = [
 #[cfg(feature = "internal")]
 pub const DIAGNOSTIC_BUILDER: [&str; 3] = ["rustc_errors", "diagnostic_builder", "DiagnosticBuilder"];
 pub const ARC_PTR_EQ: [&str; 4] = ["alloc", "sync", "Arc", "ptr_eq"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const ASSERT_EQ_MACRO: [&str; 3] = ["core", "macros", "assert_eq"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const ASSERT_MACRO: [&str; 4] = ["core", "macros", "builtin", "assert"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const ASSERT_NE_MACRO: [&str; 3] = ["core", "macros", "assert_ne"];
 pub const ASMUT_TRAIT: [&str; 3] = ["core", "convert", "AsMut"];
 pub const ASREF_TRAIT: [&str; 3] = ["core", "convert", "AsRef"];
-/// Preferably use the diagnostic item `sym::Borrow` where possible
-pub const BORROW_TRAIT: [&str; 3] = ["core", "borrow", "Borrow"];
-pub const BORROW_MUT_TRAIT: [&str; 3] = ["core", "borrow", "BorrowMut"];
 pub const BTREEMAP_CONTAINS_KEY: [&str; 6] = ["alloc", "collections", "btree", "map", "BTreeMap", "contains_key"];
 pub const BTREEMAP_ENTRY: [&str; 6] = ["alloc", "collections", "btree", "map", "entry", "Entry"];
 pub const BTREEMAP_INSERT: [&str; 6] = ["alloc", "collections", "btree", "map", "BTreeMap", "insert"];
 pub const CLONE_TRAIT_METHOD: [&str; 4] = ["core", "clone", "Clone", "clone"];
 pub const COW: [&str; 3] = ["alloc", "borrow", "Cow"];
 pub const CSTRING_AS_C_STR: [&str; 5] = ["std", "ffi", "c_str", "CString", "as_c_str"];
-pub const DEBUG_TRAIT: [&str; 3] = ["core", "fmt", "Debug"];
 pub const DEFAULT_TRAIT_METHOD: [&str; 4] = ["core", "default", "Default", "default"];
 pub const DEREF_MUT_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "DerefMut", "deref_mut"];
 /// Preferably use the diagnostic item `sym::deref_method` where possible
 pub const DEREF_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "Deref", "deref"];
 pub const DIR_BUILDER: [&str; 3] = ["std", "fs", "DirBuilder"];
 pub const DISPLAY_TRAIT: [&str; 3] = ["core", "fmt", "Display"];
-pub const DROP: [&str; 3] = ["core", "mem", "drop"];
 #[cfg(feature = "internal")]
 pub const EARLY_CONTEXT: [&str; 2] = ["rustc_lint", "EarlyContext"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const EPRINT_MACRO: [&str; 3] = ["std", "macros", "eprint"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const EPRINTLN_MACRO: [&str; 3] = ["std", "macros", "eprintln"];
 pub const EXIT: [&str; 3] = ["std", "process", "exit"];
 pub const F32_EPSILON: [&str; 4] = ["core", "f32", "<impl f32>", "EPSILON"];
 pub const F64_EPSILON: [&str; 4] = ["core", "f64", "<impl f64>", "EPSILON"];
 pub const FILE: [&str; 3] = ["std", "fs", "File"];
 pub const FILE_TYPE: [&str; 3] = ["std", "fs", "FileType"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const FORMAT_ARGS_MACRO: [&str; 4] = ["core", "macros", "builtin", "format_args"];
 pub const FROM_FROM: [&str; 4] = ["core", "convert", "From", "from"];
 pub const FROM_ITERATOR_METHOD: [&str; 6] = ["core", "iter", "traits", "collect", "FromIterator", "from_iter"];
 pub const FROM_STR_METHOD: [&str; 5] = ["core", "str", "traits", "FromStr", "from_str"];
@@ -85,17 +68,8 @@ pub const KW_MODULE: [&str; 3] = ["rustc_span", "symbol", "kw"];
 pub const LATE_CONTEXT: [&str; 2] = ["rustc_lint", "LateContext"];
 #[cfg(feature = "internal")]
 pub const LINT: [&str; 2] = ["rustc_lint_defs", "Lint"];
-pub const MEM_DISCRIMINANT: [&str; 3] = ["core", "mem", "discriminant"];
-pub const MEM_FORGET: [&str; 3] = ["core", "mem", "forget"];
-pub const MEM_MANUALLY_DROP: [&str; 4] = ["core", "mem", "manually_drop", "ManuallyDrop"];
-pub const MEM_MAYBEUNINIT: [&str; 4] = ["core", "mem", "maybe_uninit", "MaybeUninit"];
-pub const MEM_MAYBEUNINIT_UNINIT: [&str; 5] = ["core", "mem", "maybe_uninit", "MaybeUninit", "uninit"];
-pub const MEM_REPLACE: [&str; 3] = ["core", "mem", "replace"];
-pub const MEM_SIZE_OF: [&str; 3] = ["core", "mem", "size_of"];
-pub const MEM_SIZE_OF_VAL: [&str; 3] = ["core", "mem", "size_of_val"];
 pub const MUTEX_GUARD: [&str; 4] = ["std", "sync", "mutex", "MutexGuard"];
 pub const OPEN_OPTIONS: [&str; 3] = ["std", "fs", "OpenOptions"];
-pub const OPS_MODULE: [&str; 2] = ["core", "ops"];
 /// Preferably use the diagnostic item `sym::Option` where possible
 pub const OPTION: [&str; 3] = ["core", "option", "Option"];
 pub const OPTION_NONE: [&str; 4] = ["core", "option", "Option", "None"];
@@ -116,10 +90,6 @@ pub const PERMISSIONS_FROM_MODE: [&str; 6] = ["std", "os", "unix", "fs", "Permis
 pub const POLL: [&str; 4] = ["core", "task", "poll", "Poll"];
 pub const POLL_PENDING: [&str; 5] = ["core", "task", "poll", "Poll", "Pending"];
 pub const POLL_READY: [&str; 5] = ["core", "task", "poll", "Poll", "Ready"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const PRINT_MACRO: [&str; 3] = ["std", "macros", "print"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const PRINTLN_MACRO: [&str; 3] = ["std", "macros", "println"];
 pub const PTR_COPY: [&str; 3] = ["core", "intrinsics", "copy"];
 pub const PTR_COPY_NONOVERLAPPING: [&str; 3] = ["core", "intrinsics", "copy_nonoverlapping"];
 pub const PTR_EQ: [&str; 3] = ["core", "ptr", "eq"];
@@ -200,8 +170,4 @@ pub const VEC_NEW: [&str; 4] = ["alloc", "vec", "Vec", "new"];
 pub const VEC_RESIZE: [&str; 4] = ["alloc", "vec", "Vec", "resize"];
 pub const WEAK_ARC: [&str; 3] = ["alloc", "sync", "Weak"];
 pub const WEAK_RC: [&str; 3] = ["alloc", "rc", "Weak"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const WRITE_MACRO: [&str; 3] = ["core", "macros", "write"];
-#[allow(clippy::invalid_paths)] // `check_path` does not seem to work for macros
-pub const WRITELN_MACRO: [&str; 3] = ["core", "macros", "writeln"];
 pub const PTR_NON_NULL: [&str; 4] = ["core", "ptr", "non_null", "NonNull"];