Rollup of 5 pull requests

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -917,6 +917,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// The idea then is to lower the `T: 'X` constraint into multiple
     /// bounds -- e.g., if `'X` is the union of two free lifetimes,
     /// `'1` and `'2`, then we would create `T: '1` and `T: '2`.
+    #[instrument(level = "debug", skip(self, infcx, propagated_outlives_requirements))]
     fn try_promote_type_test(
         &self,
         infcx: &InferCtxt<'_, 'tcx>,
@@ -934,11 +935,41 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             return false;
         };
 
+        debug!("subject = {:?}", subject);
+
+        let r_scc = self.constraint_sccs.scc(*lower_bound);
+
+        debug!(
+            "lower_bound = {:?} r_scc={:?} universe={:?}",
+            lower_bound, r_scc, self.scc_universes[r_scc]
+        );
+
+        // If the type test requires that `T: 'a` where `'a` is a
+        // placeholder from another universe, that effectively requires
+        // `T: 'static`, so we have to propagate that requirement.
+        //
+        // It doesn't matter *what* universe because the promoted `T` will
+        // always be in the root universe.
+        if let Some(p) = self.scc_values.placeholders_contained_in(r_scc).next() {
+            debug!("encountered placeholder in higher universe: {:?}, requiring 'static", p);
+            let static_r = self.universal_regions.fr_static;
+            propagated_outlives_requirements.push(ClosureOutlivesRequirement {
+                subject,
+                outlived_free_region: static_r,
+                blame_span: locations.span(body),
+                category: ConstraintCategory::Boring,
+            });
+
+            // we can return here -- the code below might push add'l constraints
+            // but they would all be weaker than this one.
+            return true;
+        }
+
         // For each region outlived by lower_bound find a non-local,
         // universal region (it may be the same region) and add it to
         // `ClosureOutlivesRequirement`.
-        let r_scc = self.constraint_sccs.scc(*lower_bound);
         for ur in self.scc_values.universal_regions_outlived_by(r_scc) {
+            debug!("universal_region_outlived_by ur={:?}", ur);
             // Check whether we can already prove that the "subject" outlives `ur`.
             // If so, we don't have to propagate this requirement to our caller.
             //
@@ -963,8 +994,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                 continue;
             }
 
-            debug!("try_promote_type_test: ur={:?}", ur);
-
             let non_local_ub = self.universal_region_relations.non_local_upper_bounds(ur);
             debug!("try_promote_type_test: non_local_ub={:?}", non_local_ub);
 
@@ -1001,15 +1030,14 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// will use it's *external name*, which will be a `RegionKind`
     /// variant that can be used in query responses such as
     /// `ReEarlyBound`.
+    #[instrument(level = "debug", skip(self, infcx))]
     fn try_promote_type_test_subject(
         &self,
         infcx: &InferCtxt<'_, 'tcx>,
         ty: Ty<'tcx>,
     ) -> Option<ClosureOutlivesSubject<'tcx>> {
         let tcx = infcx.tcx;
 
-        debug!("try_promote_type_test_subject(ty = {:?})", ty);
-
         let ty = tcx.fold_regions(ty, |r, _depth| {
             let region_vid = self.to_region_vid(r);
 

compiler/rustc_trait_selection/src/traits/coherence.rs

@@ -13,7 +13,7 @@ use crate::traits::{
     self, FulfillmentContext, Normalized, Obligation, ObligationCause, PredicateObligation,
     PredicateObligations, SelectionContext,
 };
-//use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::Diagnostic;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
@@ -44,7 +44,7 @@ pub enum Conflict {
 
 pub struct OverlapResult<'tcx> {
     pub impl_header: ty::ImplHeader<'tcx>,
-    pub intercrate_ambiguity_causes: Vec<IntercrateAmbiguityCause>,
+    pub intercrate_ambiguity_causes: FxIndexSet<IntercrateAmbiguityCause>,
 
     /// `true` if the overlap might've been permitted before the shift
     /// to universes.

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -110,7 +110,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc }
                         };
                         debug!(?cause, "evaluate_stack: pushing cause");
-                        self.intercrate_ambiguity_causes.as_mut().unwrap().push(cause);
+                        self.intercrate_ambiguity_causes.as_mut().unwrap().insert(cause);
                     }
                 }
             }

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -24,7 +24,7 @@ use crate::traits::error_reporting::InferCtxtExt;
 use crate::traits::project::ProjectAndUnifyResult;
 use crate::traits::project::ProjectionCacheKeyExt;
 use crate::traits::ProjectionCacheKey;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{Diagnostic, ErrorGuaranteed};
 use rustc_hir as hir;
@@ -52,7 +52,7 @@ pub use rustc_middle::traits::select::*;
 mod candidate_assembly;
 mod confirmation;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
 pub enum IntercrateAmbiguityCause {
     DownstreamCrate { trait_desc: String, self_desc: Option<String> },
     UpstreamCrateUpdate { trait_desc: String, self_desc: Option<String> },
@@ -128,7 +128,7 @@ pub struct SelectionContext<'cx, 'tcx> {
     /// We don't do his until we detect a coherence error because it can
     /// lead to false overflow results (#47139) and because always
     /// computing it may negatively impact performance.
-    intercrate_ambiguity_causes: Option<Vec<IntercrateAmbiguityCause>>,
+    intercrate_ambiguity_causes: Option<FxIndexSet<IntercrateAmbiguityCause>>,
 
     /// The mode that trait queries run in, which informs our error handling
     /// policy. In essence, canonicalized queries need their errors propagated
@@ -254,14 +254,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     pub fn enable_tracking_intercrate_ambiguity_causes(&mut self) {
         assert!(self.intercrate);
         assert!(self.intercrate_ambiguity_causes.is_none());
-        self.intercrate_ambiguity_causes = Some(vec![]);
+        self.intercrate_ambiguity_causes = Some(FxIndexSet::default());
         debug!("selcx: enable_tracking_intercrate_ambiguity_causes");
     }
 
     /// Gets the intercrate ambiguity causes collected since tracking
     /// was enabled and disables tracking at the same time. If
     /// tracking is not enabled, just returns an empty vector.
-    pub fn take_intercrate_ambiguity_causes(&mut self) -> Vec<IntercrateAmbiguityCause> {
+    pub fn take_intercrate_ambiguity_causes(&mut self) -> FxIndexSet<IntercrateAmbiguityCause> {
         assert!(self.intercrate);
         self.intercrate_ambiguity_causes.take().unwrap_or_default()
     }
@@ -960,7 +960,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                             });
 
                             debug!(?cause, "evaluate_stack: pushing cause");
-                            self.intercrate_ambiguity_causes.as_mut().unwrap().push(cause);
+                            self.intercrate_ambiguity_causes.as_mut().unwrap().insert(cause);
                         }
                     }
                 }
@@ -1252,7 +1252,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                                  reservation impl ambiguity on {:?}",
                             def_id
                         );
-                        intercrate_ambiguity_clauses.push(
+                        intercrate_ambiguity_clauses.insert(
                             IntercrateAmbiguityCause::ReservationImpl {
                                 message: value.to_string(),
                             },

compiler/rustc_trait_selection/src/traits/specialize/mod.rs

@@ -15,7 +15,7 @@ use specialization_graph::GraphExt;
 use crate::infer::{InferCtxt, InferOk, TyCtxtInferExt};
 use crate::traits::select::IntercrateAmbiguityCause;
 use crate::traits::{self, coherence, FutureCompatOverlapErrorKind, ObligationCause, TraitEngine};
-use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
 use rustc_errors::{struct_span_err, EmissionGuarantee, LintDiagnosticBuilder};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef};
@@ -33,7 +33,7 @@ pub struct OverlapError {
     pub with_impl: DefId,
     pub trait_desc: String,
     pub self_desc: Option<String>,
-    pub intercrate_ambiguity_causes: Vec<IntercrateAmbiguityCause>,
+    pub intercrate_ambiguity_causes: FxIndexSet<IntercrateAmbiguityCause>,
     pub involves_placeholder: bool,
 }
 

library/core/src/sync/atomic.rs

@@ -991,7 +991,7 @@ impl<T> AtomicPtr<T> {
     /// use std::sync::atomic::AtomicPtr;
     ///
     /// let ptr = &mut 5;
-    /// let atomic_ptr  = AtomicPtr::new(ptr);
+    /// let atomic_ptr = AtomicPtr::new(ptr);
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]

src/librustdoc/config.rs

@@ -329,6 +329,17 @@ impl Options {
             return Err(0);
         }
 
+        let z_flags = matches.opt_strs("Z");
+        if z_flags.iter().any(|x| *x == "help") {
+            print_flag_list("-Z", config::DB_OPTIONS);
+            return Err(0);
+        }
+        let c_flags = matches.opt_strs("C");
+        if c_flags.iter().any(|x| *x == "help") {
+            print_flag_list("-C", config::CG_OPTIONS);
+            return Err(0);
+        }
+
         let color = config::parse_color(matches);
         let config::JsonConfig { json_rendered, json_unused_externs, .. } =
             config::parse_json(matches);
@@ -343,17 +354,6 @@ impl Options {
         // check for deprecated options
         check_deprecated_options(matches, &diag);
 
-        let z_flags = matches.opt_strs("Z");
-        if z_flags.iter().any(|x| *x == "help") {
-            print_flag_list("-Z", config::DB_OPTIONS);
-            return Err(0);
-        }
-        let c_flags = matches.opt_strs("C");
-        if c_flags.iter().any(|x| *x == "help") {
-            print_flag_list("-C", config::CG_OPTIONS);
-            return Err(0);
-        }
-
         if matches.opt_strs("passes") == ["list"] {
             println!("Available passes for running rustdoc:");
             for pass in passes::PASSES {

src/librustdoc/html/static/css/themes/dark.css

@@ -178,9 +178,6 @@ a {
 	color: #D2991D;
 }
 
-a.test-arrow {
-	color: #dedede;
-}
 body.source .example-wrap pre.rust a {
 	background: #333;
 }
@@ -255,6 +252,7 @@ pre.rust .question-mark {
 }
 
 a.test-arrow {
+	color: #dedede;
 	background-color: rgba(78, 139, 202, 0.2);
 }
 

src/librustdoc/html/static/css/themes/light.css

@@ -175,9 +175,6 @@ a {
 	color: #3873AD;
 }
 
-a.test-arrow {
-	color: #f5f5f5;
-}
 body.source .example-wrap pre.rust a {
 	background: #eee;
 }
@@ -239,7 +236,8 @@ pre.rust .question-mark {
 }
 
 a.test-arrow {
-	background-color: rgb(78, 139, 202, 0.2);
+	color: #f5f5f5;
+	background-color: rgba(78, 139, 202, 0.2);
 }
 
 a.test-arrow:hover{

src/test/rustdoc-ui/c-help.rs

@@ -0,0 +1,6 @@
+// check-pass
+// compile-flags: -Chelp
+// check-stdout
+// regex-error-pattern: -C\s+incremental
+
+pub struct Foo;

src/test/rustdoc-ui/c-help.stdout

@@ -0,0 +1,51 @@
+    -C                       ar=val -- this option is deprecated and does nothing
+    -C               code-model=val -- choose the code model to use (`rustc --print code-models` for details)
+    -C            codegen-units=val -- divide crate into N units to optimize in parallel
+    -C       control-flow-guard=val -- use Windows Control Flow Guard (default: no)
+    -C         debug-assertions=val -- explicitly enable the `cfg(debug_assertions)` directive
+    -C                debuginfo=val -- debug info emission level (0 = no debug info, 1 = line tables only, 2 = full debug info with variable and type information; default: 0)
+    -C default-linker-libraries=val -- allow the linker to link its default libraries (default: no)
+    -C            embed-bitcode=val -- emit bitcode in rlibs (default: yes)
+    -C           extra-filename=val -- extra data to put in each output filename
+    -C     force-frame-pointers=val -- force use of the frame pointers
+    -C      force-unwind-tables=val -- force use of unwind tables
+    -C              incremental=val -- enable incremental compilation
+    -C         inline-threshold=val -- set the threshold for inlining a function
+    -C      instrument-coverage=val -- instrument the generated code to support LLVM source-based code coverage reports (note, the compiler build config must include `profiler = true`); implies `-C symbol-mangling-version=v0`. Optional values are:
+        `=all` (implicit value)
+        `=except-unused-generics`
+        `=except-unused-functions`
+        `=off` (default)
+    -C                 link-arg=val -- a single extra argument to append to the linker invocation (can be used several times)
+    -C                link-args=val -- extra arguments to append to the linker invocation (space separated)
+    -C           link-dead-code=val -- keep dead code at link time (useful for code coverage) (default: no)
+    -C      link-self-contained=val -- control whether to link Rust provided C objects/libraries or rely
+        on C toolchain installed in the system
+    -C                   linker=val -- system linker to link outputs with
+    -C            linker-flavor=val -- linker flavor
+    -C        linker-plugin-lto=val -- generate build artifacts that are compatible with linker-based LTO
+    -C                llvm-args=val -- a list of arguments to pass to LLVM (space separated)
+    -C                      lto=val -- perform LLVM link-time optimizations
+    -C                 metadata=val -- metadata to mangle symbol names with
+    -C    no-prepopulate-passes=val -- give an empty list of passes to the pass manager
+    -C               no-redzone=val -- disable the use of the redzone
+    -C           no-stack-check=val -- this option is deprecated and does nothing
+    -C       no-vectorize-loops=val -- disable loop vectorization optimization passes
+    -C         no-vectorize-slp=val -- disable LLVM's SLP vectorization pass
+    -C                opt-level=val -- optimization level (0-3, s, or z; default: 0)
+    -C          overflow-checks=val -- use overflow checks for integer arithmetic
+    -C                    panic=val -- panic strategy to compile crate with
+    -C                   passes=val -- a list of extra LLVM passes to run (space separated)
+    -C           prefer-dynamic=val -- prefer dynamic linking to static linking (default: no)
+    -C         profile-generate=val -- compile the program with profiling instrumentation
+    -C              profile-use=val -- use the given `.profdata` file for profile-guided optimization
+    -C         relocation-model=val -- control generation of position-independent code (PIC) (`rustc --print relocation-models` for details)
+    -C                   remark=val -- print remarks for these optimization passes (space separated, or "all")
+    -C                    rpath=val -- set rpath values in libs/exes (default: no)
+    -C               save-temps=val -- save all temporary output files during compilation (default: no)
+    -C               soft-float=val -- use soft float ABI (*eabihf targets only) (default: no)
+    -C          split-debuginfo=val -- how to handle split-debuginfo, a platform-specific option
+    -C                    strip=val -- tell the linker which information to strip (`none` (default), `debuginfo` or `symbols`)
+    -C  symbol-mangling-version=val -- which mangling version to use for symbol names ('legacy' (default) or 'v0')
+    -C               target-cpu=val -- select target processor (`rustc --print target-cpus` for details)
+    -C           target-feature=val -- target specific attributes. (`rustc --print target-features` for details). This feature is unsafe.

src/test/rustdoc-ui/z-help.rs

@@ -0,0 +1,6 @@
+// check-pass
+// compile-flags: -Zhelp
+// check-stdout
+// regex-error-pattern: -Z\s+self-profile
+
+pub struct Foo;