Auto merge of rust-lang#79345 - jonas-schievink:rollup-1yhhzx9, r=jonas-schievink

Rollup of 10 pull requests

Successful merges:

 - rust-lang#76829 (stabilize const_int_pow)
 - rust-lang#79080 (MIR visitor: Don't treat debuginfo field access as a use of the struct)
 - rust-lang#79236 (const_generics: assert resolve hack causes an error)
 - rust-lang#79287 (Allow using generic trait methods in `const fn`)
 - rust-lang#79324 (Use Option::and_then instead of open-coding it)
 - rust-lang#79325 (Reduce boilerplate with the `?` operator)
 - rust-lang#79330 (Fix typo in comment)
 - rust-lang#79333 (doc typo)
 - rust-lang#79337 (Use Option::map instead of open coding it)
 - rust-lang#79343 (Add my (`@flip1995)` work mail to the mailmap)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

.mailmap

@@ -230,6 +230,7 @@ Phil Dawes <phil@phildawes.net> Phil Dawes <pdawes@drw.com>
 Philipp Brüschweiler <blei42@gmail.com> <blei42@gmail.com>
 Philipp Brüschweiler <blei42@gmail.com> <bruphili@student.ethz.ch>
 Philipp Krones <hello@philkrones.com> flip1995 <hello@philkrones.com>
+Philipp Krones <hello@philkrones.com> <philipp.krones@embecosm.com>
 Philipp Matthias Schäfer <philipp.matthias.schaefer@posteo.de>
 Przemysław Wesołek <jest@go.art.pl> Przemek Wesołek <jest@go.art.pl>
 Rafael Ávila de Espíndola <respindola@mozilla.com> Rafael Avila de Espindola <espindola@dream.(none)>

compiler/rustc_builtin_macros/src/format_foreign.rs

@@ -649,17 +649,13 @@ pub mod shell {
     impl<'a> Iterator for Substitutions<'a> {
         type Item = Substitution<'a>;
         fn next(&mut self) -> Option<Self::Item> {
-            match parse_next_substitution(self.s) {
-                Some((mut sub, tail)) => {
-                    self.s = tail;
-                    if let Some(InnerSpan { start, end }) = sub.position() {
-                        sub.set_position(start + self.pos, end + self.pos);
-                        self.pos += end;
-                    }
-                    Some(sub)
-                }
-                None => None,
+            let (mut sub, tail) = parse_next_substitution(self.s)?;
+            self.s = tail;
+            if let Some(InnerSpan { start, end }) = sub.position() {
+                sub.set_position(start + self.pos, end + self.pos);
+                self.pos += end;
             }
+            Some(sub)
         }
 
         fn size_hint(&self) -> (usize, Option<usize>) {

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -1152,10 +1152,7 @@ impl<'ll> MemberDescription<'ll> {
                 self.size.bits(),
                 self.align.bits() as u32,
                 self.offset.bits(),
-                match self.discriminant {
-                    None => None,
-                    Some(value) => Some(cx.const_u64(value)),
-                },
+                self.discriminant.map(|v| cx.const_u64(v)),
                 self.flags,
                 self.type_metadata,
             )

compiler/rustc_codegen_ssa/src/mir/block.rs

@@ -37,12 +37,9 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> {
     /// `funclet_bb` member if it is not `None`.
     fn funclet<'b, Bx: BuilderMethods<'a, 'tcx>>(
         &self,
-        fx: &'b mut FunctionCx<'a, 'tcx, Bx>,
+        fx: &'b FunctionCx<'a, 'tcx, Bx>,
     ) -> Option<&'b Bx::Funclet> {
-        match self.funclet_bb {
-            Some(funcl) => fx.funclets[funcl].as_ref(),
-            None => None,
-        }
+        self.funclet_bb.and_then(|funcl| fx.funclets[funcl].as_ref())
     }
 
     fn lltarget<Bx: BuilderMethods<'a, 'tcx>>(

compiler/rustc_infer/src/traits/util.rs

@@ -309,7 +309,7 @@ impl<'tcx, I: Iterator<Item = PredicateObligation<'tcx>>> Iterator for FilterToT
     fn next(&mut self) -> Option<ty::PolyTraitRef<'tcx>> {
         while let Some(obligation) = self.base_iterator.next() {
             if let Some(data) = obligation.predicate.to_opt_poly_trait_ref() {
-                return Some(data);
+                return Some(data.value);
             }
         }
         None

compiler/rustc_middle/src/mir/visit.rs

@@ -1017,11 +1017,14 @@ macro_rules! visit_place_fns {
             let mut context = context;
 
             if !place.projection.is_empty() {
-                context = if context.is_mutating_use() {
-                    PlaceContext::MutatingUse(MutatingUseContext::Projection)
-                } else {
-                    PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
-                };
+                if context.is_use() {
+                    // ^ Only change the context if it is a real use, not a "use" in debuginfo.
+                    context = if context.is_mutating_use() {
+                        PlaceContext::MutatingUse(MutatingUseContext::Projection)
+                    } else {
+                        PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
+                    };
+                }
             }
 
             self.visit_local(&place.local, context, location);

compiler/rustc_middle/src/traits/mod.rs

@@ -16,6 +16,7 @@ use crate::ty::{self, AdtKind, Ty, TyCtxt};
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
+use rustc_hir::Constness;
 use rustc_span::symbol::Symbol;
 use rustc_span::{Span, DUMMY_SP};
 use smallvec::SmallVec;
@@ -457,7 +458,7 @@ pub enum ImplSource<'tcx, N> {
     /// for some type parameter. The `Vec<N>` represents the
     /// obligations incurred from normalizing the where-clause (if
     /// any).
-    Param(Vec<N>),
+    Param(Vec<N>, Constness),
 
     /// Virtual calls through an object.
     Object(ImplSourceObjectData<'tcx, N>),
@@ -487,7 +488,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
     pub fn nested_obligations(self) -> Vec<N> {
         match self {
             ImplSource::UserDefined(i) => i.nested,
-            ImplSource::Param(n) => n,
+            ImplSource::Param(n, _) => n,
             ImplSource::Builtin(i) => i.nested,
             ImplSource::AutoImpl(d) => d.nested,
             ImplSource::Closure(c) => c.nested,
@@ -502,7 +503,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
     pub fn borrow_nested_obligations(&self) -> &[N] {
         match &self {
             ImplSource::UserDefined(i) => &i.nested[..],
-            ImplSource::Param(n) => &n[..],
+            ImplSource::Param(n, _) => &n[..],
             ImplSource::Builtin(i) => &i.nested[..],
             ImplSource::AutoImpl(d) => &d.nested[..],
             ImplSource::Closure(c) => &c.nested[..],
@@ -524,7 +525,7 @@ impl<'tcx, N> ImplSource<'tcx, N> {
                 substs: i.substs,
                 nested: i.nested.into_iter().map(f).collect(),
             }),
-            ImplSource::Param(n) => ImplSource::Param(n.into_iter().map(f).collect()),
+            ImplSource::Param(n, ct) => ImplSource::Param(n.into_iter().map(f).collect(), ct),
             ImplSource::Builtin(i) => ImplSource::Builtin(ImplSourceBuiltinData {
                 nested: i.nested.into_iter().map(f).collect(),
             }),

compiler/rustc_middle/src/traits/select.rs

@@ -101,7 +101,7 @@ pub enum SelectionCandidate<'tcx> {
         /// `false` if there are no *further* obligations.
         has_nested: bool,
     },
-    ParamCandidate(ty::PolyTraitRef<'tcx>),
+    ParamCandidate(ty::ConstnessAnd<ty::PolyTraitRef<'tcx>>),
     ImplCandidate(DefId),
     AutoImplCandidate(DefId),
 

compiler/rustc_middle/src/traits/structural_impls.rs

@@ -21,7 +21,9 @@ impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSource<'tcx, N> {
 
             super::ImplSource::Object(ref d) => write!(f, "{:?}", d),
 
-            super::ImplSource::Param(ref n) => write!(f, "ImplSourceParamData({:?})", n),
+            super::ImplSource::Param(ref n, ct) => {
+                write!(f, "ImplSourceParamData({:?}, {:?})", n, ct)
+            }
 
             super::ImplSource::Builtin(ref d) => write!(f, "{:?}", d),
 

compiler/rustc_middle/src/ty/context.rs

@@ -42,7 +42,9 @@ use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId, LOCAL_CRATE};
 use rustc_hir::definitions::{DefPathHash, Definitions};
 use rustc_hir::intravisit::Visitor;
 use rustc_hir::lang_items::LangItem;
-use rustc_hir::{HirId, ItemKind, ItemLocalId, ItemLocalMap, ItemLocalSet, Node, TraitCandidate};
+use rustc_hir::{
+    Constness, HirId, ItemKind, ItemLocalId, ItemLocalMap, ItemLocalSet, Node, TraitCandidate,
+};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_macros::HashStable;
 use rustc_session::config::{BorrowckMode, CrateType, OutputFilenames};
@@ -1635,6 +1637,8 @@ nop_list_lift! {projs; ProjectionKind => ProjectionKind}
 // This is the impl for `&'a InternalSubsts<'a>`.
 nop_list_lift! {substs; GenericArg<'a> => GenericArg<'tcx>}
 
+CloneLiftImpls! { for<'tcx> { Constness, } }
+
 pub mod tls {
     use super::{ptr_eq, GlobalCtxt, TyCtxt};