Rollup merge of #119974 - nnethercote:trimmed_def_paths-improvements, r=compiler-errors

Minor `trimmed_def_paths` improvements

r? `@compiler-errors`

compiler/rustc_driver_impl/src/lib.rs

@@ -35,7 +35,7 @@
 use rustc_metadata::creader::MetadataLoader;
 use rustc_metadata::locator;
 use rustc_session::config::{nightly_options, CG_OPTIONS, Z_OPTIONS};
-use rustc_session::config::{ErrorOutputType, Input, OutFileName, OutputType, TrimmedDefPaths};
+use rustc_session::config::{ErrorOutputType, Input, OutFileName, OutputType};
 use rustc_session::getopts::{self, Matches};
 use rustc_session::lint::{Lint, LintId};
 use rustc_session::{config, EarlyDiagCtxt, Session};
@@ -204,7 +204,7 @@ fn config(&mut self, config: &mut interface::Config) {
         //
         self.time_passes = (config.opts.prints.is_empty() && config.opts.unstable_opts.time_passes)
             .then(|| config.opts.unstable_opts.time_passes_format);
-        config.opts.trimmed_def_paths = TrimmedDefPaths::GoodPath;
+        config.opts.trimmed_def_paths = true;
     }
 }
 

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -15,7 +15,6 @@
 use rustc_hir::def_id::{DefIdMap, DefIdSet, ModDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::definitions::{DefKey, DefPathDataName};
 use rustc_hir::LangItem;
-use rustc_session::config::TrimmedDefPaths;
 use rustc_session::cstore::{ExternCrate, ExternCrateSource};
 use rustc_session::Limit;
 use rustc_span::symbol::{kw, Ident, Symbol};
@@ -365,26 +364,19 @@ fn force_print_trimmed_def_path(&mut self, def_id: DefId) -> Result<bool, PrintE
 
     /// Try to see if this path can be trimmed to a unique symbol name.
     fn try_print_trimmed_def_path(&mut self, def_id: DefId) -> Result<bool, PrintError> {
-        if with_forced_trimmed_paths() {
-            let trimmed = self.force_print_trimmed_def_path(def_id)?;
-            if trimmed {
+        if with_forced_trimmed_paths() && self.force_print_trimmed_def_path(def_id)? {
             return Ok(true);
         }
-        }
-        if !self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths
-            || matches!(self.tcx().sess.opts.trimmed_def_paths, TrimmedDefPaths::Never)
-            || with_no_trimmed_paths()
-            || with_crate_prefix()
+        if self.tcx().sess.opts.unstable_opts.trim_diagnostic_paths
+            && self.tcx().sess.opts.trimmed_def_paths
+            && !with_no_trimmed_paths()
+            && !with_crate_prefix()
+            && let Some(symbol) = self.tcx().trimmed_def_paths(()).get(&def_id)
         {
-            return Ok(false);
-        }
-
-        match self.tcx().trimmed_def_paths(()).get(&def_id) {
-            None => Ok(false),
-            Some(symbol) => {
             write!(self, "{}", Ident::with_dummy_span(*symbol))?;
             Ok(true)
-            }
+        } else {
+            Ok(false)
         }
     }
 
@@ -3080,18 +3072,19 @@ fn for_each_def(tcx: TyCtxt<'_>, mut collect_fn: impl for<'b> FnMut(&'b Ident, N
 /// See also [`DelayDm`](rustc_error_messages::DelayDm) and [`with_no_trimmed_paths!`].
 // this is pub to be able to intra-doc-link it
 pub fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> DefIdMap<Symbol> {
-    let mut map: DefIdMap<Symbol> = Default::default();
+    assert!(tcx.sess.opts.trimmed_def_paths);
 
-    if let TrimmedDefPaths::GoodPath = tcx.sess.opts.trimmed_def_paths {
-        // Trimming paths is expensive and not optimized, since we expect it to only be used for error reporting.
+    // Trimming paths is expensive and not optimized, since we expect it to only be used for error
+    // reporting.
     //
     // For good paths causing this bug, the `rustc_middle::ty::print::with_no_trimmed_paths`
     // wrapper can be used to suppress this query, in exchange for full paths being formatted.
     tcx.sess.good_path_delayed_bug(
         "trimmed_def_paths constructed but no error emitted; use `DelayDm` for lints or `with_no_trimmed_paths` for debugging",
     );
-    }
 
+    // Once constructed, unique namespace+symbol pairs will have a `Some(_)` entry, while
+    // non-unique pairs will have a `None` entry.
     let unique_symbols_rev: &mut FxHashMap<(Namespace, Symbol), Option<DefId>> =
         &mut FxHashMap::default();
 
@@ -3121,6 +3114,8 @@ pub fn trimmed_def_paths(tcx: TyCtxt<'_>, (): ()) -> DefIdMap<Symbol> {
         }
     });
 
+    // Put the symbol from all the unique namespace+symbol pairs into `map`.
+    let mut map: DefIdMap<Symbol> = Default::default();
     for ((_, symbol), opt_def_id) in unique_symbols_rev.drain() {
         use std::collections::hash_map::Entry::{Occupied, Vacant};
 

compiler/rustc_session/src/config.rs

@@ -533,21 +533,6 @@ fn default() -> Self {
     }
 }
 
-/// Parameter to control path trimming.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash)]
-pub enum TrimmedDefPaths {
-    /// `try_print_trimmed_def_path` never prints a trimmed path and never calls the expensive
-    /// query.
-    #[default]
-    Never,
-    /// `try_print_trimmed_def_path` calls the expensive query, the query doesn't call
-    /// `good_path_delayed_bug`.
-    Always,
-    /// `try_print_trimmed_def_path` calls the expensive query, the query calls
-    /// `good_path_delayed_bug`.
-    GoodPath,
-}
-
 #[derive(Clone, Hash, Debug)]
 pub enum ResolveDocLinks {
     /// Do not resolve doc links.
@@ -1089,7 +1074,7 @@ fn default() -> Options {
             debug_assertions: true,
             actually_rustdoc: false,
             resolve_doc_links: ResolveDocLinks::None,
-            trimmed_def_paths: TrimmedDefPaths::default(),
+            trimmed_def_paths: false,
             cli_forced_codegen_units: None,
             cli_forced_local_thinlto_off: false,
             remap_path_prefix: Vec::new(),
@@ -2926,7 +2911,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         debug_assertions,
         actually_rustdoc: false,
         resolve_doc_links: ResolveDocLinks::ExportedMetadata,
-        trimmed_def_paths: TrimmedDefPaths::default(),
+        trimmed_def_paths: false,
         cli_forced_codegen_units: codegen_units,
         cli_forced_local_thinlto_off: disable_local_thinlto,
         remap_path_prefix,
@@ -3210,7 +3195,7 @@ pub(crate) mod dep_tracking {
         LinkerPluginLto, LocationDetail, LtoCli, NextSolverConfig, OomStrategy, OptLevel,
         OutFileName, OutputType, OutputTypes, Polonius, RemapPathScopeComponents, ResolveDocLinks,
         SourceFileHashAlgorithm, SplitDwarfKind, SwitchWithOptPath, SymbolManglingVersion,
-        TrimmedDefPaths, WasiExecModel,
+        WasiExecModel,
     };
     use crate::lint;
     use crate::utils::NativeLib;
@@ -3305,7 +3290,6 @@ fn hash(
         SymbolManglingVersion,
         RemapPathScopeComponents,
         SourceFileHashAlgorithm,
-        TrimmedDefPaths,
         OutFileName,
         OutputType,
         RealFileName,

compiler/rustc_session/src/options.rs

@@ -183,7 +183,7 @@ pub struct Options {
         resolve_doc_links: ResolveDocLinks [TRACKED],
 
         /// Control path trimming.
-        trimmed_def_paths: TrimmedDefPaths [TRACKED],
+        trimmed_def_paths: bool [TRACKED],
 
         /// Specifications of codegen units / ThinLTO which are forced as a
         /// result of parsing command line options. These are not necessarily