Auto merge of rust-lang#90891 - nbdd0121:format, r=Mark-Simulacrum

Create `core::fmt::ArgumentV1` with generics instead of fn pointer

Split from (and prerequisite of) rust-lang#90488, as this seems to have perf implication.

`@rustbot` label: +T-libs

Author: bors

clippy_lints/src/index_refutable_slice.rs

@@ -4,7 +4,7 @@ use clippy_utils::higher::IfLet;
 use clippy_utils::ty::is_copy;
 use clippy_utils::{is_expn_of, is_lint_allowed, meets_msrv, msrvs, path_to_local};
 use if_chain::if_chain;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
@@ -92,9 +92,9 @@ impl<'tcx> LateLintPass<'tcx> for IndexRefutableSlice {
     extract_msrv_attr!(LateContext);
 }
 
-fn find_slice_values(cx: &LateContext<'_>, pat: &hir::Pat<'_>) -> FxHashMap<hir::HirId, SliceLintInformation> {
+fn find_slice_values(cx: &LateContext<'_>, pat: &hir::Pat<'_>) -> FxIndexMap<hir::HirId, SliceLintInformation> {
     let mut removed_pat: FxHashSet<hir::HirId> = FxHashSet::default();
-    let mut slices: FxHashMap<hir::HirId, SliceLintInformation> = FxHashMap::default();
+    let mut slices: FxIndexMap<hir::HirId, SliceLintInformation> = FxIndexMap::default();
     pat.walk_always(|pat| {
         if let hir::PatKind::Binding(binding, value_hir_id, ident, sub_pat) = pat.kind {
             // We'll just ignore mut and ref mut for simplicity sake right now
@@ -208,10 +208,10 @@ impl SliceLintInformation {
 
 fn filter_lintable_slices<'a, 'tcx>(
     cx: &'a LateContext<'tcx>,
-    slice_lint_info: FxHashMap<hir::HirId, SliceLintInformation>,
+    slice_lint_info: FxIndexMap<hir::HirId, SliceLintInformation>,
     max_suggested_slice: u64,
     scope: &'tcx hir::Expr<'tcx>,
-) -> FxHashMap<hir::HirId, SliceLintInformation> {
+) -> FxIndexMap<hir::HirId, SliceLintInformation> {
     let mut visitor = SliceIndexLintingVisitor {
         cx,
         slice_lint_info,
@@ -225,7 +225,7 @@ fn filter_lintable_slices<'a, 'tcx>(
 
 struct SliceIndexLintingVisitor<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
-    slice_lint_info: FxHashMap<hir::HirId, SliceLintInformation>,
+    slice_lint_info: FxIndexMap<hir::HirId, SliceLintInformation>,
     max_suggested_slice: u64,
 }
 

clippy_utils/src/macros.rs

@@ -339,15 +339,13 @@ impl<'tcx> FormatArgsExpn<'tcx> {
         expr_visitor_no_bodies(|e| {
             // if we're still inside of the macro definition...
             if e.span.ctxt() == expr.span.ctxt() {
-                // ArgumnetV1::new(<value>, <format_trait>::fmt)
+                // ArgumnetV1::new_<format_trait>(<value>)
                 if_chain! {
-                    if let ExprKind::Call(callee, [val, fmt_path]) = e.kind;
+                    if let ExprKind::Call(callee, [val]) = e.kind;
                     if let ExprKind::Path(QPath::TypeRelative(ty, seg)) = callee.kind;
-                    if seg.ident.name == sym::new;
                     if let hir::TyKind::Path(QPath::Resolved(_, path)) = ty.kind;
                     if path.segments.last().unwrap().ident.name == sym::ArgumentV1;
-                    if let ExprKind::Path(QPath::Resolved(_, path)) = fmt_path.kind;
-                    if let [.., fmt_trait, _fmt] = path.segments;
+                    if seg.ident.name.as_str().starts_with("new_");
                     then {
                         let val_idx = if_chain! {
                             if val.span.ctxt() == expr.span.ctxt();
@@ -361,7 +359,19 @@ impl<'tcx> FormatArgsExpn<'tcx> {
                                 formatters.len()
                             }
                         };
-                        formatters.push((val_idx, fmt_trait.ident.name));
+                        let fmt_trait = match seg.ident.name.as_str() {
+                            "new_display" => "Display",
+                            "new_debug" => "Debug",
+                            "new_lower_exp" => "LowerExp",
+                            "new_upper_exp" => "UpperExp",
+                            "new_octal" => "Octal",
+                            "new_pointer" => "Pointer",
+                            "new_binary" => "Binary",
+                            "new_lower_hex" => "LowerHex",
+                            "new_upper_hex" => "UpperHex",
+                            _ => unreachable!(),
+                        };
+                        formatters.push((val_idx, Symbol::intern(fmt_trait)));
                     }
                 }
                 if let ExprKind::Struct(QPath::Resolved(_, path), ..) = e.kind {