From f7931c805097f97c9586f0ce49d01ff4adfc972c Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Fri, 30 Jan 2026 18:21:19 -0800 Subject: [PATCH] Remove some unnecessary `try`-related type annotations I left a few, like ```rust let result: Result<_, ModError<'_>> = try { ``` where it felt like seeing it might still be useful for the reader. Feel free to push back on any of these changes if you think seeing the type would be better. --- compiler/rustc_borrowck/src/nll.rs | 4 +-- compiler/rustc_borrowck/src/polonius/dump.rs | 2 +- compiler/rustc_codegen_ssa/src/back/linker.rs | 16 +++++----- compiler/rustc_driver_impl/src/lib.rs | 2 +- .../rustc_expand/src/proc_macro_server.rs | 4 +-- .../src/check/compare_impl_item.rs | 4 +-- compiler/rustc_interface/src/passes.rs | 2 +- compiler/rustc_lint/src/types.rs | 31 +++++++++---------- compiler/rustc_middle/src/mir/pretty.rs | 4 +-- .../rustc_mir_build/src/builder/custom/mod.rs | 2 +- compiler/rustc_privacy/src/lib.rs | 6 ++-- .../error_reporting/infer/need_type_info.rs | 15 +++++---- 12 files changed, 45 insertions(+), 47 deletions(-) diff --git a/compiler/rustc_borrowck/src/nll.rs b/compiler/rustc_borrowck/src/nll.rs index 64e3b59acfff..7cb27638e645 100644 --- a/compiler/rustc_borrowck/src/nll.rs +++ b/compiler/rustc_borrowck/src/nll.rs @@ -230,13 +230,13 @@ pub(super) fn dump_nll_mir<'tcx>( dumper.dump_mir(body); // Also dump the region constraint graph as a graphviz file. - let _: io::Result<()> = try { + let _ = try { let mut file = dumper.create_dump_file("regioncx.all.dot", body)?; regioncx.dump_graphviz_raw_constraints(tcx, &mut file)?; }; // Also dump the region constraint SCC graph as a graphviz file. - let _: io::Result<()> = try { + let _ = try { let mut file = dumper.create_dump_file("regioncx.scc.dot", body)?; regioncx.dump_graphviz_scc_constraints(tcx, &mut file)?; }; diff --git a/compiler/rustc_borrowck/src/polonius/dump.rs b/compiler/rustc_borrowck/src/polonius/dump.rs index 62f9ae173474..a8e7ab234f00 100644 --- a/compiler/rustc_borrowck/src/polonius/dump.rs +++ b/compiler/rustc_borrowck/src/polonius/dump.rs @@ -58,7 +58,7 @@ pub(crate) fn dump_polonius_mir<'tcx>( let dumper = dumper.set_extra_data(extra_data).set_options(options); - let _: io::Result<()> = try { + let _ = try { let mut file = dumper.create_dump_file("html", body)?; emit_polonius_dump( &dumper, diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs index db49f92e39ac..10c4eedb58e8 100644 --- a/compiler/rustc_codegen_ssa/src/back/linker.rs +++ b/compiler/rustc_codegen_ssa/src/back/linker.rs @@ -2,7 +2,7 @@ use std::ffi::{OsStr, OsString}; use std::fs::{self, File}; use std::io::prelude::*; use std::path::{Path, PathBuf}; -use std::{env, io, iter, mem, str}; +use std::{env, iter, mem, str}; use find_msvc_tools; use rustc_hir::attrs::WindowsSubsystemKind; @@ -809,7 +809,7 @@ impl<'a> Linker for GccLinker<'a> { if self.sess.target.is_like_darwin { // Write a plain, newline-separated list of symbols - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; for (sym, _) in symbols { debug!(" _{sym}"); @@ -821,7 +821,7 @@ impl<'a> Linker for GccLinker<'a> { } self.link_arg("-exported_symbols_list").link_arg(path); } else if self.sess.target.is_like_windows { - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; // .def file similar to MSVC one but without LIBRARY section @@ -845,7 +845,7 @@ impl<'a> Linker for GccLinker<'a> { self.link_arg("--export").link_arg(sym); } } else if crate_type == CrateType::Executable && !self.sess.target.is_like_solaris { - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; writeln!(f, "{{")?; for (sym, _) in symbols { @@ -860,7 +860,7 @@ impl<'a> Linker for GccLinker<'a> { self.link_arg("--dynamic-list").link_arg(path); } else { // Write an LD version script - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; writeln!(f, "{{")?; if !symbols.is_empty() { @@ -1139,7 +1139,7 @@ impl<'a> Linker for MsvcLinker<'a> { } let path = tmpdir.join("lib.def"); - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; // Start off with the standard module name header and then go @@ -1735,7 +1735,7 @@ impl<'a> Linker for AixLinker<'a> { symbols: &[(String, SymbolExportKind)], ) { let path = tmpdir.join("list.exp"); - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; // FIXME: use llvm-nm to generate export list. for (symbol, _) in symbols { @@ -2135,7 +2135,7 @@ impl<'a> Linker for BpfLinker<'a> { symbols: &[(String, SymbolExportKind)], ) { let path = tmpdir.join("symbols"); - let res: io::Result<()> = try { + let res = try { let mut f = File::create_buffered(&path)?; for (sym, _) in symbols { writeln!(f, "{sym}")?; diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs index 38ee87601614..5579c25329eb 100644 --- a/compiler/rustc_driver_impl/src/lib.rs +++ b/compiler/rustc_driver_impl/src/lib.rs @@ -537,7 +537,7 @@ fn show_md_content_with_pager(content: &str, color: ColorConfig) { }; // Try to print via the pager, pretty output if possible. - let pager_res: Option<()> = try { + let pager_res = try { let mut pager = cmd.stdin(Stdio::piped()).spawn().ok()?; let pager_stdin = pager.stdin.as_mut()?; diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs index 12490880ab0e..947b8a6e3e5e 100644 --- a/compiler/rustc_expand/src/proc_macro_server.rs +++ b/compiler/rustc_expand/src/proc_macro_server.rs @@ -7,7 +7,7 @@ use rustc_ast::tokenstream::{self, DelimSpacing, Spacing, TokenStream}; use rustc_ast::util::literal::escape_byte_str_symbol; use rustc_ast_pretty::pprust; use rustc_data_structures::fx::FxHashMap; -use rustc_errors::{Diag, ErrorGuaranteed, MultiSpan, PResult}; +use rustc_errors::{Diag, ErrorGuaranteed, MultiSpan}; use rustc_parse::lexer::{StripTokens, nfc_normalize}; use rustc_parse::parser::Parser; use rustc_parse::{exp, new_parser_from_source_str, source_str_to_stream, unwrap_or_emit_fatal}; @@ -591,7 +591,7 @@ impl server::Server for Rustc<'_, '_> { fn ts_expand_expr(&mut self, stream: &Self::TokenStream) -> Result { // Parse the expression from our tokenstream. - let expr: PResult<'_, _> = try { + let expr = try { let mut p = Parser::new(self.psess(), stream.clone(), Some("proc_macro expand expr")); let expr = p.parse_expr()?; if p.token != token::Eof { diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs index dd7b03c9dac3..777929eaadb8 100644 --- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs +++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs @@ -1845,7 +1845,7 @@ fn compare_synthetic_generics<'tcx>( // The case where the impl method uses `impl Trait` but the trait method uses // explicit generics err.span_label(impl_span, "expected generic parameter, found `impl Trait`"); - let _: Option<_> = try { + try { // try taking the name from the trait impl // FIXME: this is obviously suboptimal since the name can already be used // as another generic argument @@ -1882,7 +1882,7 @@ fn compare_synthetic_generics<'tcx>( // The case where the trait method uses `impl Trait`, but the impl method uses // explicit generics. err.span_label(impl_span, "expected `impl Trait`, found generic parameter"); - let _: Option<_> = try { + try { let impl_m = impl_m.def_id.as_local()?; let impl_m = tcx.hir_expect_impl_item(impl_m); let (sig, _) = impl_m.expect_fn(); diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs index f5fb8031ab0f..35f8c44b685d 100644 --- a/compiler/rustc_interface/src/passes.rs +++ b/compiler/rustc_interface/src/passes.rs @@ -582,7 +582,7 @@ fn write_out_deps(tcx: TyCtxt<'_>, outputs: &OutputFilenames, out_filenames: &[P let deps_output = outputs.path(OutputType::DepInfo); let deps_filename = deps_output.as_path(); - let result: io::Result<()> = try { + let result = try { // Build a list of files used to compile the output and // write Makefile-compatible dependency rules let mut files: IndexMap)> = sess diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs index f3e6db6f2d8e..47e1fef8b82e 100644 --- a/compiler/rustc_lint/src/types.rs +++ b/compiler/rustc_lint/src/types.rs @@ -746,24 +746,23 @@ fn pat_ty_is_known_nonnull<'tcx>( typing_env: ty::TypingEnv<'tcx>, pat: ty::Pattern<'tcx>, ) -> bool { - Option::unwrap_or_default( - try { - match *pat { - ty::PatternKind::Range { start, end } => { - let start = start.try_to_value()?.try_to_bits(tcx, typing_env)?; - let end = end.try_to_value()?.try_to_bits(tcx, typing_env)?; + try { + match *pat { + ty::PatternKind::Range { start, end } => { + let start = start.try_to_value()?.try_to_bits(tcx, typing_env)?; + let end = end.try_to_value()?.try_to_bits(tcx, typing_env)?; - // This also works for negative numbers, as we just need - // to ensure we aren't wrapping over zero. - start > 0 && end >= start - } - ty::PatternKind::NotNull => true, - ty::PatternKind::Or(patterns) => { - patterns.iter().all(|pat| pat_ty_is_known_nonnull(tcx, typing_env, pat)) - } + // This also works for negative numbers, as we just need + // to ensure we aren't wrapping over zero. + start > 0 && end >= start } - }, - ) + ty::PatternKind::NotNull => true, + ty::PatternKind::Or(patterns) => { + patterns.iter().all(|pat| pat_ty_is_known_nonnull(tcx, typing_env, pat)) + } + } + } + .unwrap_or_default() } /// Given a non-null scalar (or transparent) type `ty`, return the nullable version of that type. diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs index ded02595563c..2e6e96b4d8a8 100644 --- a/compiler/rustc_middle/src/mir/pretty.rs +++ b/compiler/rustc_middle/src/mir/pretty.rs @@ -157,13 +157,13 @@ impl<'dis, 'de, 'tcx> MirDumper<'dis, 'de, 'tcx> { /// - `foo & nll | bar & typeck` == match if `foo` and `nll` both appear in the name /// or `typeck` and `bar` both appear in the name. pub fn dump_mir(&self, body: &Body<'tcx>) { - let _: io::Result<()> = try { + let _ = try { let mut file = self.create_dump_file("mir", body)?; self.dump_mir_to_writer(body, &mut file)?; }; if self.tcx().sess.opts.unstable_opts.dump_mir_graphviz { - let _: io::Result<()> = try { + let _ = try { let mut file = self.create_dump_file("dot", body)?; write_mir_fn_graphviz(self.tcx(), body, false, &mut file)?; }; diff --git a/compiler/rustc_mir_build/src/builder/custom/mod.rs b/compiler/rustc_mir_build/src/builder/custom/mod.rs index 792ad6d782cf..1005dd30d73f 100644 --- a/compiler/rustc_mir_build/src/builder/custom/mod.rs +++ b/compiler/rustc_mir_build/src/builder/custom/mod.rs @@ -85,7 +85,7 @@ pub(super) fn build_custom_mir<'tcx>( block_map: FxHashMap::default(), }; - let res: PResult<_> = try { + let res = try { pctxt.parse_args(params)?; pctxt.parse_body(expr)?; }; diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs index 333677521023..19c030a94e5c 100644 --- a/compiler/rustc_privacy/src/lib.rs +++ b/compiler/rustc_privacy/src/lib.rs @@ -1159,14 +1159,14 @@ impl<'tcx> TypePrivacyVisitor<'tcx> { let typeck_results = self .maybe_typeck_results .unwrap_or_else(|| span_bug!(span, "`hir::Expr` or `hir::Pat` outside of a body")); - let result: ControlFlow<()> = try { + try { self.visit(typeck_results.node_type(id))?; self.visit(typeck_results.node_args(id))?; if let Some(adjustments) = typeck_results.adjustments().get(id) { adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?; } - }; - result.is_break() + } + .is_break() } fn check_def_id(&self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool { diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs index e3c8bfe4a452..b8f11189a11f 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs @@ -1023,7 +1023,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { hir::ExprKind::MethodCall(segment, ..) => { if let Some(def_id) = self.typeck_results.type_dependent_def_id(expr.hir_id) { let generics = tcx.generics_of(def_id); - let insertable: Option<_> = try { + let insertable = try { if generics.has_impl_trait() { None? } @@ -1061,7 +1061,7 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { // // FIXME: We deal with that one separately for now, // would be good to remove this special case. - let last_segment_using_path_data: Option<_> = try { + let last_segment_using_path_data = try { let generics_def_id = tcx.res_generics_def_id(path.res)?; let generics = tcx.generics_of(generics_def_id); if generics.has_impl_trait() { @@ -1117,19 +1117,18 @@ impl<'a, 'tcx> FindInferSourceVisitor<'a, 'tcx> { }; let generics = tcx.generics_of(def_id); - let segment: Option<_> = try { - if !segment.infer_args || generics.has_impl_trait() { - do yeet (); - } + let segment = if !segment.infer_args || generics.has_impl_trait() { + None + } else { let span = tcx.hir_span(segment.hir_id); let insert_span = segment.ident.span.shrink_to_hi().with_hi(span.hi()); - InsertableGenericArgs { + Some(InsertableGenericArgs { insert_span, args, generics_def_id: def_id, def_id, have_turbofish: false, - } + }) }; let parent_def_id = generics.parent.unwrap();