Rollup of 6 pull requests

.git-blame-ignore-revs

@@ -0,0 +1,6 @@
+# format the world
+a06baa56b95674fc626b3c3fd680d6a65357fe60
+# format libcore
+95e00bfed801e264e9c4ac817004153ca0f19eb6
+# reformat with new rustfmt
+971c549ca334b7b7406e61e958efcca9c4152822

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -55,75 +55,93 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         infcx: &InferCtxt<'_, 'tcx>,
         opaque_ty_decls: VecMap<OpaqueTypeKey<'tcx>, (OpaqueHiddenType<'tcx>, OpaqueTyOrigin)>,
     ) -> VecMap<OpaqueTypeKey<'tcx>, OpaqueHiddenType<'tcx>> {
-        opaque_ty_decls
-            .into_iter()
-            .map(|(opaque_type_key, (concrete_type, origin))| {
-                let substs = opaque_type_key.substs;
-                debug!(?concrete_type, ?substs);
+        let mut result: VecMap<OpaqueTypeKey<'tcx>, OpaqueHiddenType<'tcx>> = VecMap::new();
+        for (opaque_type_key, (concrete_type, origin)) in opaque_ty_decls {
+            let substs = opaque_type_key.substs;
+            debug!(?concrete_type, ?substs);
 
-                let mut subst_regions = vec![self.universal_regions.fr_static];
-                let universal_substs = infcx.tcx.fold_regions(substs, &mut false, |region, _| {
-                    if let ty::RePlaceholder(..) = region.kind() {
-                        // Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs.
-                        return region;
+            let mut subst_regions = vec![self.universal_regions.fr_static];
+            let universal_substs = infcx.tcx.fold_regions(substs, &mut false, |region, _| {
+                if let ty::RePlaceholder(..) = region.kind() {
+                    // Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs.
+                    return region;
+                }
+                let vid = self.to_region_vid(region);
+                trace!(?vid);
+                let scc = self.constraint_sccs.scc(vid);
+                trace!(?scc);
+                match self.scc_values.universal_regions_outlived_by(scc).find_map(|lb| {
+                    self.eval_equal(vid, lb).then_some(self.definitions[lb].external_name?)
+                }) {
+                    Some(region) => {
+                        let vid = self.universal_regions.to_region_vid(region);
+                        subst_regions.push(vid);
+                        region
                     }
-                    let vid = self.to_region_vid(region);
-                    trace!(?vid);
-                    let scc = self.constraint_sccs.scc(vid);
-                    trace!(?scc);
-                    match self.scc_values.universal_regions_outlived_by(scc).find_map(|lb| {
-                        self.eval_equal(vid, lb).then_some(self.definitions[lb].external_name?)
-                    }) {
-                        Some(region) => {
-                            let vid = self.universal_regions.to_region_vid(region);
-                            subst_regions.push(vid);
-                            region
-                        }
-                        None => {
-                            subst_regions.push(vid);
-                            infcx.tcx.sess.delay_span_bug(
-                                concrete_type.span,
-                                "opaque type with non-universal region substs",
-                            );
-                            infcx.tcx.lifetimes.re_static
-                        }
+                    None => {
+                        subst_regions.push(vid);
+                        infcx.tcx.sess.delay_span_bug(
+                            concrete_type.span,
+                            "opaque type with non-universal region substs",
+                        );
+                        infcx.tcx.lifetimes.re_static
                     }
-                });
+                }
+            });
 
-                subst_regions.sort();
-                subst_regions.dedup();
+            subst_regions.sort();
+            subst_regions.dedup();
 
-                let universal_concrete_type =
-                    infcx.tcx.fold_regions(concrete_type, &mut false, |region, _| match *region {
-                        ty::ReVar(vid) => subst_regions
-                            .iter()
-                            .find(|ur_vid| self.eval_equal(vid, **ur_vid))
-                            .and_then(|ur_vid| self.definitions[*ur_vid].external_name)
-                            .unwrap_or(infcx.tcx.lifetimes.re_root_empty),
-                        _ => region,
-                    });
+            let universal_concrete_type =
+                infcx.tcx.fold_regions(concrete_type, &mut false, |region, _| match *region {
+                    ty::ReVar(vid) => subst_regions
+                        .iter()
+                        .find(|ur_vid| self.eval_equal(vid, **ur_vid))
+                        .and_then(|ur_vid| self.definitions[*ur_vid].external_name)
+                        .unwrap_or(infcx.tcx.lifetimes.re_root_empty),
+                    _ => region,
+                });
 
-                debug!(?universal_concrete_type, ?universal_substs);
+            debug!(?universal_concrete_type, ?universal_substs);
 
-                let opaque_type_key =
-                    OpaqueTypeKey { def_id: opaque_type_key.def_id, substs: universal_substs };
-                let remapped_type = infcx.infer_opaque_definition_from_instantiation(
-                    opaque_type_key,
-                    universal_concrete_type,
-                );
-                let ty = if check_opaque_type_parameter_valid(
-                    infcx.tcx,
-                    opaque_type_key,
-                    origin,
-                    concrete_type.span,
-                ) {
-                    remapped_type
-                } else {
-                    infcx.tcx.ty_error()
-                };
-                (opaque_type_key, OpaqueHiddenType { ty, span: concrete_type.span })
-            })
-            .collect()
+            let opaque_type_key =
+                OpaqueTypeKey { def_id: opaque_type_key.def_id, substs: universal_substs };
+            let remapped_type = infcx.infer_opaque_definition_from_instantiation(
+                opaque_type_key,
+                universal_concrete_type,
+            );
+            let ty = if check_opaque_type_parameter_valid(
+                infcx.tcx,
+                opaque_type_key,
+                origin,
+                concrete_type.span,
+            ) {
+                remapped_type
+            } else {
+                infcx.tcx.ty_error()
+            };
+            // Sometimes two opaque types are the same only after we remap the generic parameters
+            // back to the opaque type definition. E.g. we may have `OpaqueType<X, Y>` mapped to `(X, Y)`
+            // and `OpaqueType<Y, X>` mapped to `(Y, X)`, and those are the same, but we only know that
+            // once we convert the generic parameters to those of the opaque type.
+            if let Some(prev) = result.get_mut(&opaque_type_key) {
+                if prev.ty != ty {
+                    let mut err = infcx.tcx.sess.struct_span_err(
+                        concrete_type.span,
+                        &format!("hidden type `{}` differed from previous `{}`", ty, prev.ty),
+                    );
+                    err.span_note(prev.span, "previous hidden type bound here");
+                    err.emit();
+                    prev.ty = infcx.tcx.ty_error();
+                }
+                // Pick a better span if there is one.
+                // FIXME(oli-obk): collect multiple spans for better diagnostics down the road.
+                prev.span = prev.span.substitute_dummy(concrete_type.span);
+            } else {
+                result.insert(opaque_type_key, OpaqueHiddenType { ty, span: concrete_type.span });
+            }
+        }
+        result
     }
 
     /// Map the regions in the type to named regions. This is similar to what

compiler/rustc_mir_transform/src/deref_separator.rs

@@ -0,0 +1,72 @@
+use crate::MirPass;
+use rustc_middle::mir::patch::MirPatch;
+use rustc_middle::mir::*;
+use rustc_middle::ty::TyCtxt;
+pub struct Derefer;
+
+pub fn deref_finder<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+    let mut patch = MirPatch::new(body);
+    let (basic_blocks, local_decl) = body.basic_blocks_and_local_decls_mut();
+    for (block, data) in basic_blocks.iter_enumerated_mut() {
+        for (i, stmt) in data.statements.iter_mut().enumerate() {
+            match stmt.kind {
+                StatementKind::Assign(box (og_place, Rvalue::Ref(region, borrow_knd, place))) => {
+                    for (idx, (p_ref, p_elem)) in place.iter_projections().enumerate() {
+                        if p_elem == ProjectionElem::Deref && !p_ref.projection.is_empty() {
+                            // The type that we are derefing.
+                            let ty = p_ref.ty(local_decl, tcx).ty;
+                            let temp = patch.new_temp(ty, stmt.source_info.span);
+
+                            // Because we are assigning this right before original statement
+                            // we are using index i of statement.
+                            let loc = Location { block: block, statement_index: i };
+                            patch.add_statement(loc, StatementKind::StorageLive(temp));
+
+                            // We are adding current p_ref's projections to our
+                            // temp value.
+                            let deref_place =
+                                Place::from(p_ref.local).project_deeper(p_ref.projection, tcx);
+                            patch.add_assign(
+                                loc,
+                                Place::from(temp),
+                                Rvalue::Use(Operand::Move(deref_place)),
+                            );
+
+                            // We are creating a place by using our temp value's location
+                            // and copying derefed values which we need to create new statement.
+                            let temp_place =
+                                Place::from(temp).project_deeper(&place.projection[idx..], tcx);
+                            let new_stmt = Statement {
+                                source_info: stmt.source_info,
+                                kind: StatementKind::Assign(Box::new((
+                                    og_place,
+                                    Rvalue::Ref(region, borrow_knd, temp_place),
+                                ))),
+                            };
+
+                            // Replace current statement with newly created one.
+                            *stmt = new_stmt;
+
+                            // Since our job with the temp is done it should be gone
+                            let loc = Location { block: block, statement_index: i + 1 };
+                            patch.add_statement(loc, StatementKind::StorageDead(temp));
+
+                            // As all projections are off the base projection, if there are
+                            // multiple derefs in the middle of projection, it might cause
+                            // unsoundness, to not let that happen we break the loop.
+                            break;
+                        }
+                    }
+                }
+                _ => (),
+            }
+        }
+    }
+    patch.apply(body);
+}
+
+impl<'tcx> MirPass<'tcx> for Derefer {
+    fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
+        deref_finder(tcx, body);
+    }
+}

compiler/rustc_mir_transform/src/lib.rs

@@ -53,6 +53,7 @@ mod const_prop_lint;
 mod coverage;
 mod deaggregator;
 mod deduplicate_blocks;
+mod deref_separator;
 mod dest_prop;
 pub mod dump_mir;
 mod early_otherwise_branch;
@@ -431,6 +432,7 @@ fn run_post_borrowck_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tc
         // `Deaggregator` is conceptually part of MIR building, some backends rely on it happening
         // and it can help optimizations.
         &deaggregator::Deaggregator,
+        &deref_separator::Derefer,
         &Lint(const_prop_lint::ConstProp),
     ];
 

library/std/src/panicking.rs

@@ -20,7 +20,7 @@ use crate::process;
 use crate::sync::atomic::{AtomicBool, Ordering};
 use crate::sys::stdio::panic_output;
 use crate::sys_common::backtrace;
-use crate::sys_common::rwlock::StaticRWLock;
+use crate::sys_common::rwlock::StaticRwLock;
 use crate::sys_common::thread_info;
 use crate::thread;
 
@@ -83,7 +83,7 @@ impl Hook {
     }
 }
 
-static HOOK_LOCK: StaticRWLock = StaticRWLock::new();
+static HOOK_LOCK: StaticRwLock = StaticRwLock::new();
 static mut HOOK: Hook = Hook::Default;
 
 /// Registers a custom panic hook, replacing any that was previously registered.

library/std/src/sync/rwlock.rs

@@ -76,7 +76,7 @@ use crate::sys_common::rwlock as sys;
 /// [`Mutex`]: super::Mutex
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct RwLock<T: ?Sized> {
-    inner: sys::MovableRWLock,
+    inner: sys::MovableRwLock,
     poison: poison::Flag,
     data: UnsafeCell<T>,
 }
@@ -146,7 +146,7 @@ impl<T> RwLock<T> {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn new(t: T) -> RwLock<T> {
         RwLock {
-            inner: sys::MovableRWLock::new(),
+            inner: sys::MovableRwLock::new(),
             poison: poison::Flag::new(),
             data: UnsafeCell::new(t),
         }

library/std/src/sys/hermit/rwlock.rs

@@ -1,22 +1,22 @@
 use crate::cell::UnsafeCell;
 use crate::sys::locks::{Condvar, Mutex};
 
-pub struct RWLock {
+pub struct RwLock {
     lock: Mutex,
     cond: Condvar,
     state: UnsafeCell<State>,
 }
 
-pub type MovableRWLock = RWLock;
+pub type MovableRwLock = RwLock;
 
 enum State {
     Unlocked,
     Reading(usize),
     Writing,
 }
 
-unsafe impl Send for RWLock {}
-unsafe impl Sync for RWLock {}
+unsafe impl Send for RwLock {}
+unsafe impl Sync for RwLock {}
 
 // This rwlock implementation is a relatively simple implementation which has a
 // condition variable for readers/writers as well as a mutex protecting the
@@ -26,9 +26,9 @@ unsafe impl Sync for RWLock {}
 // hopefully correct this implementation is very likely to want to be changed in
 // the future.
 
-impl RWLock {
-    pub const fn new() -> RWLock {
-        RWLock { lock: Mutex::new(), cond: Condvar::new(), state: UnsafeCell::new(State::Unlocked) }
+impl RwLock {
+    pub const fn new() -> RwLock {
+        RwLock { lock: Mutex::new(), cond: Condvar::new(), state: UnsafeCell::new(State::Unlocked) }
     }
 
     #[inline]

library/std/src/sys/sgx/rwlock.rs

@@ -8,25 +8,25 @@ use super::waitqueue::{
 };
 use crate::mem;
 
-pub struct RWLock {
+pub struct RwLock {
     readers: SpinMutex<WaitVariable<Option<NonZeroUsize>>>,
     writer: SpinMutex<WaitVariable<bool>>,
 }
 
-pub type MovableRWLock = Box<RWLock>;
+pub type MovableRwLock = Box<RwLock>;
 
-// Check at compile time that RWLock size matches C definition (see test_c_rwlock_initializer below)
+// Check at compile time that RwLock size matches C definition (see test_c_rwlock_initializer below)
 //
 // # Safety
 // Never called, as it is a compile time check.
 #[allow(dead_code)]
-unsafe fn rw_lock_size_assert(r: RWLock) {
-    unsafe { mem::transmute::<RWLock, [u8; 144]>(r) };
+unsafe fn rw_lock_size_assert(r: RwLock) {
+    unsafe { mem::transmute::<RwLock, [u8; 144]>(r) };
 }
 
-impl RWLock {
-    pub const fn new() -> RWLock {
-        RWLock {
+impl RwLock {
+    pub const fn new() -> RwLock {
+        RwLock {
             readers: SpinMutex::new(WaitVariable::new(None)),
             writer: SpinMutex::new(WaitVariable::new(false)),
         }
@@ -180,7 +180,7 @@ const EINVAL: i32 = 22;
 
 #[cfg(not(test))]
 #[no_mangle]
-pub unsafe extern "C" fn __rust_rwlock_rdlock(p: *mut RWLock) -> i32 {
+pub unsafe extern "C" fn __rust_rwlock_rdlock(p: *mut RwLock) -> i32 {
     if p.is_null() {
         return EINVAL;
     }
@@ -190,7 +190,7 @@ pub unsafe extern "C" fn __rust_rwlock_rdlock(p: *mut RWLock) -> i32 {
 
 #[cfg(not(test))]
 #[no_mangle]
-pub unsafe extern "C" fn __rust_rwlock_wrlock(p: *mut RWLock) -> i32 {
+pub unsafe extern "C" fn __rust_rwlock_wrlock(p: *mut RwLock) -> i32 {
     if p.is_null() {
         return EINVAL;
     }
@@ -199,7 +199,7 @@ pub unsafe extern "C" fn __rust_rwlock_wrlock(p: *mut RWLock) -> i32 {
 }
 #[cfg(not(test))]
 #[no_mangle]
-pub unsafe extern "C" fn __rust_rwlock_unlock(p: *mut RWLock) -> i32 {
+pub unsafe extern "C" fn __rust_rwlock_unlock(p: *mut RwLock) -> i32 {
     if p.is_null() {
         return EINVAL;
     }