Rollup of 19 pull requests

compiler/rustc_ast_lowering/src/path.rs

@@ -273,7 +273,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         if !generic_args.parenthesized && !has_lifetimes {
             generic_args.args = self
                 .elided_path_lifetimes(
-                    first_generic_span.map(|s| s.shrink_to_lo()).unwrap_or(segment.ident.span),
+                    first_generic_span.map_or(segment.ident.span, |s| s.shrink_to_lo()),
                     expected_lifetimes,
                 )
                 .map(GenericArg::Lifetime)

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -370,7 +370,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                     gate_feature_post!(
                         &self,
                         negative_impls,
-                        span.to(of_trait.as_ref().map(|t| t.path.span).unwrap_or(span)),
+                        span.to(of_trait.as_ref().map_or(span, |t| t.path.span)),
                         "negative trait bounds are not yet fully implemented; \
                          use marker types for now"
                     );

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -1002,8 +1002,7 @@ pub unsafe fn with_llvm_pmb(
     // reasonable defaults and prepare it to actually populate the pass
     // manager.
     let builder = llvm::LLVMPassManagerBuilderCreate();
-    let opt_size =
-        config.opt_size.map(|x| to_llvm_opt_settings(x).1).unwrap_or(llvm::CodeGenOptSizeNone);
+    let opt_size = config.opt_size.map_or(llvm::CodeGenOptSizeNone, |x| to_llvm_opt_settings(x).1);
     let inline_threshold = config.inline_threshold;
     let pgo_gen_path = get_pgo_gen_path(config);
     let pgo_use_path = get_pgo_use_path(config);

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -552,7 +552,6 @@ impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
 
         unsafe {
             llvm::LLVMRustDIBuilderCreateDebugLocation(
-                utils::debug_context(self).llcontext,
                 line.unwrap_or(UNKNOWN_LINE_NUMBER),
                 col.unwrap_or(UNKNOWN_COLUMN_NUMBER),
                 scope,

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -2102,7 +2102,6 @@ extern "C" {
     );
 
     pub fn LLVMRustDIBuilderCreateDebugLocation(
-        Context: &'a Context,
         Line: c_uint,
         Column: c_uint,
         Scope: &'a DIScope,

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -166,7 +166,7 @@ fn get_linker(
         _ => match flavor {
             LinkerFlavor::Lld(f) => Command::lld(linker, f),
             LinkerFlavor::Msvc if sess.opts.cg.linker.is_none() && sess.target.linker.is_none() => {
-                Command::new(msvc_tool.as_ref().map(|t| t.path()).unwrap_or(linker))
+                Command::new(msvc_tool.as_ref().map_or(linker, |t| t.path()))
             }
             _ => Command::new(linker),
         },

compiler/rustc_data_structures/src/profiling.rs

@@ -166,7 +166,7 @@ impl SelfProfilerRef {
         // If there is no SelfProfiler then the filter mask is set to NONE,
         // ensuring that nothing ever tries to actually access it.
         let event_filter_mask =
-            profiler.as_ref().map(|p| p.event_filter_mask).unwrap_or(EventFilter::empty());
+            profiler.as_ref().map_or(EventFilter::empty(), |p| p.event_filter_mask);
 
         SelfProfilerRef {
             profiler,

compiler/rustc_driver/src/lib.rs

@@ -798,7 +798,7 @@ pub fn version(binary: &str, matches: &getopts::Matches) {
         println!("commit-date: {}", unw(util::commit_date_str()));
         println!("host: {}", config::host_triple());
         println!("release: {}", unw(util::release_str()));
-        if cfg!(llvm) {
+        if cfg!(feature = "llvm") {
             get_builtin_codegen_backend("llvm")().print_version();
         }
     }
@@ -1087,7 +1087,7 @@ pub fn handle_options(args: &[String]) -> Option<getopts::Matches> {
     }
 
     if cg_flags.iter().any(|x| *x == "passes=list") {
-        if cfg!(llvm) {
+        if cfg!(feature = "llvm") {
             get_builtin_codegen_backend("llvm")().print_passes();
         }
         return None;
@@ -1236,7 +1236,7 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     }
 
     // If backtraces are enabled, also print the query stack
-    let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
+    let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
 
     let num_frames = if backtrace { None } else { Some(2) };
 

compiler/rustc_errors/src/lib.rs

@@ -804,7 +804,7 @@ impl HandlerInner {
     }
 
     fn treat_err_as_bug(&self) -> bool {
-        self.flags.treat_err_as_bug.map(|c| self.err_count() >= c).unwrap_or(false)
+        self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() >= c)
     }
 
     fn print_error_count(&mut self, registry: &Registry) {
@@ -913,7 +913,7 @@ impl HandlerInner {
         // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
         // incrementing `err_count` by one, so we need to +1 the comparing.
         // FIXME: Would be nice to increment err_count in a more coherent way.
-        if self.flags.treat_err_as_bug.map(|c| self.err_count() + 1 >= c).unwrap_or(false) {
+        if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c) {
             // FIXME: don't abort here if report_delayed_bugs is off
             self.span_bug(sp, msg);
         }

compiler/rustc_expand/src/config.rs

@@ -423,7 +423,7 @@ impl<'a> StripUnconfigured<'a> {
 
     /// If attributes are not allowed on expressions, emit an error for `attr`
     pub fn maybe_emit_expr_attr_err(&self, attr: &Attribute) {
-        if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true) {
+        if !self.features.map_or(true, |features| features.stmt_expr_attributes) {
             let mut err = feature_err(
                 &self.sess.parse_sess,
                 sym::stmt_expr_attributes,

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -500,7 +500,7 @@ fn inner_parse_loop<'root, 'tt>(
                 if idx == len && item.sep.is_some() {
                     // We have a separator, and it is the current token. We can advance past the
                     // separator token.
-                    if item.sep.as_ref().map(|sep| token_name_eq(token, sep)).unwrap_or(false) {
+                    if item.sep.as_ref().map_or(false, |sep| token_name_eq(token, sep)) {
                         item.idx += 1;
                         next_items.push(item);
                     }

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -203,7 +203,7 @@ fn macro_rules_dummy_expander<'cx>(
 }
 
 fn trace_macros_note(cx_expansions: &mut FxHashMap<Span, Vec<String>>, sp: Span, message: String) {
-    let sp = sp.macro_backtrace().last().map(|trace| trace.call_site).unwrap_or(sp);
+    let sp = sp.macro_backtrace().last().map_or(sp, |trace| trace.call_site);
     cx_expansions.entry(sp).or_default().push(message);
 }
 

compiler/rustc_expand/src/mbe/quoted.rs

@@ -99,10 +99,10 @@ pub(super) fn parse(
                                 }
                                 _ => token.span,
                             },
-                            tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
+                            tree => tree.as_ref().map_or(span, tokenstream::TokenTree::span),
                         }
                     }
-                    tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(start_sp),
+                    tree => tree.as_ref().map_or(start_sp, tokenstream::TokenTree::span),
                 };
                 if node_id != DUMMY_NODE_ID {
                     // Macros loaded from other crates have dummy node ids.
@@ -250,7 +250,7 @@ fn parse_kleene_op(
             Some(op) => Ok(Ok((op, token.span))),
             None => Ok(Err(token)),
         },
-        tree => Err(tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span)),
+        tree => Err(tree.as_ref().map_or(span, tokenstream::TokenTree::span)),
     }
 }
 

compiler/rustc_hir/src/hir.rs

@@ -561,7 +561,7 @@ impl WhereClause<'_> {
     ///  in `fn foo<T>(t: T) where T: Foo,` so we don't suggest two trailing commas.
     pub fn tail_span_for_suggestion(&self) -> Span {
         let end = self.span_for_predicates_or_empty_place().shrink_to_hi();
-        self.predicates.last().map(|p| p.span()).unwrap_or(end).shrink_to_hi().to(end)
+        self.predicates.last().map_or(end, |p| p.span()).shrink_to_hi().to(end)
     }
 }
 

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -2118,7 +2118,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 let consider = format!(
                     "{} {}...",
                     msg,
-                    if type_param_span.map(|(_, _, is_impl_trait)| is_impl_trait).unwrap_or(false) {
+                    if type_param_span.map_or(false, |(_, _, is_impl_trait)| is_impl_trait) {
                         format!(" `{}` to `{}`", sub, bound_kind)
                     } else {
                         format!("`{}: {}`", bound_kind, sub)

compiler/rustc_infer/src/infer/mod.rs

@@ -1533,7 +1533,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 // Note: if these two lines are combined into one we get
                 // dynamic borrow errors on `self.inner`.
                 let known = self.inner.borrow_mut().type_variables().probe(v).known();
-                known.map(|t| self.shallow_resolve_ty(t)).unwrap_or(typ)
+                known.map_or(typ, |t| self.shallow_resolve_ty(t))
             }
 
             ty::Infer(ty::IntVar(v)) => self

compiler/rustc_lint/src/types.rs

@@ -647,8 +647,7 @@ pub fn transparent_newtype_field<'a, 'tcx>(
     let param_env = tcx.param_env(variant.def_id);
     for field in &variant.fields {
         let field_ty = tcx.type_of(field.did);
-        let is_zst =
-            tcx.layout_of(param_env.and(field_ty)).map(|layout| layout.is_zst()).unwrap_or(false);
+        let is_zst = tcx.layout_of(param_env.and(field_ty)).map_or(false, |layout| layout.is_zst());
 
         if !is_zst {
             return Some(field);

compiler/rustc_lint/src/unused.rs

@@ -529,8 +529,8 @@ trait UnusedDelimLint {
             pprust::expr_to_string(value)
         };
         let keep_space = (
-            left_pos.map(|s| s >= value.span.lo()).unwrap_or(false),
-            right_pos.map(|s| s <= value.span.hi()).unwrap_or(false),
+            left_pos.map_or(false, |s| s >= value.span.lo()),
+            right_pos.map_or(false, |s| s <= value.span.hi()),
         );
         self.emit_unused_delims(cx, value.span, &expr_text, ctx.into(), keep_space);
     }

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -994,11 +994,9 @@ LLVMRustDICompositeTypeReplaceArrays(LLVMRustDIBuilderRef Builder,
 }
 
 extern "C" LLVMMetadataRef
-LLVMRustDIBuilderCreateDebugLocation(LLVMContextRef ContextRef, unsigned Line,
-                                     unsigned Column, LLVMMetadataRef Scope,
+LLVMRustDIBuilderCreateDebugLocation(unsigned Line, unsigned Column,
+                                     LLVMMetadataRef Scope,
                                      LLVMMetadataRef InlinedAt) {
-  LLVMContext &Context = *unwrap(ContextRef);
-
   DebugLoc debug_loc = DebugLoc::get(Line, Column, unwrapDIPtr<MDNode>(Scope),
                                      unwrapDIPtr<MDNode>(InlinedAt));
 

compiler/rustc_macros/src/query.rs

@@ -429,7 +429,7 @@ fn add_query_description_impl(
     };
 
     let (tcx, desc) = modifiers.desc;
-    let tcx = tcx.as_ref().map(|t| quote! { #t }).unwrap_or(quote! { _ });
+    let tcx = tcx.as_ref().map_or(quote! { _ }, |t| quote! { #t });
 
     let desc = quote! {
         #[allow(unused_variables)]

compiler/rustc_metadata/src/creader.rs

@@ -326,7 +326,7 @@ impl<'a> CrateLoader<'a> {
         self.verify_no_symbol_conflicts(&crate_root)?;
 
         let private_dep =
-            self.sess.opts.externs.get(&name.as_str()).map(|e| e.is_private_dep).unwrap_or(false);
+            self.sess.opts.externs.get(&name.as_str()).map_or(false, |e| e.is_private_dep);
 
         // Claim this crate number and cache it
         let cnum = self.cstore.alloc_new_crate_num();

compiler/rustc_metadata/src/native_libs.rs

@@ -132,7 +132,7 @@ impl ItemLikeVisitor<'tcx> for Collector<'tcx> {
 
 impl Collector<'tcx> {
     fn register_native_lib(&mut self, span: Option<Span>, lib: NativeLib) {
-        if lib.name.as_ref().map(|&s| s == kw::Empty).unwrap_or(false) {
+        if lib.name.as_ref().map_or(false, |&s| s == kw::Empty) {
             match span {
                 Some(span) => {
                     struct_span_err!(

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -29,9 +29,10 @@
 //!   contained no `DefId` for thing that had been removed.
 //!
 //! `DepNode` definition happens in the `define_dep_nodes!()` macro. This macro
-//! defines the `DepKind` enum and a corresponding `dep_constructor` module. The
-//! `dep_constructor` module links a `DepKind` to the parameters that are needed at
-//! runtime in order to construct a valid `DepNode` fingerprint.
+//! defines the `DepKind` enum. Each `DepKind` has its own parameters that are
+//! needed at runtime in order to construct a valid `DepNode` fingerprint.
+//! However, only `CompileCodegenUnit` is constructed explicitly (with
+//! `make_compile_codegen_unit`).
 //!
 //! Because the macro sees what parameters a given `DepKind` requires, it can
 //! "infer" some properties for each kind of `DepNode`:
@@ -44,22 +45,14 @@
 //!   `DefId` it was computed from. In other cases, too much information gets
 //!   lost during fingerprint computation.
 //!
-//! The `dep_constructor` module, together with `DepNode::new()`, ensures that only
+//! `make_compile_codegen_unit`, together with `DepNode::new()`, ensures that only
 //! valid `DepNode` instances can be constructed. For example, the API does not
 //! allow for constructing parameterless `DepNode`s with anything other
 //! than a zeroed out fingerprint. More generally speaking, it relieves the
 //! user of the `DepNode` API of having to know how to compute the expected
 //! fingerprint for a given set of node parameters.
 
-use crate::mir::interpret::{GlobalId, LitToConstInput};
-use crate::traits;
-use crate::traits::query::{
-    CanonicalPredicateGoal, CanonicalProjectionGoal, CanonicalTyGoal,
-    CanonicalTypeOpAscribeUserTypeGoal, CanonicalTypeOpEqGoal, CanonicalTypeOpNormalizeGoal,
-    CanonicalTypeOpProvePredicateGoal, CanonicalTypeOpSubtypeGoal,
-};
-use crate::ty::subst::{GenericArg, SubstsRef};
-use crate::ty::{self, ParamEnvAnd, Ty, TyCtxt};
+use crate::ty::TyCtxt;
 
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX};
@@ -338,25 +331,6 @@ macro_rules! define_dep_nodes {
             $($variant),*
         }
 
-        #[allow(non_camel_case_types)]
-        pub mod dep_constructor {
-            use super::*;
-
-            $(
-                #[inline(always)]
-                #[allow(unreachable_code, non_snake_case)]
-                pub fn $variant(_tcx: TyCtxt<'_>, $(arg: $tuple_arg_ty)*) -> DepNode {
-                    // tuple args
-                    $({
-                        erase!($tuple_arg_ty);
-                        return DepNode::construct(_tcx, DepKind::$variant, &arg)
-                    })*
-
-                    return DepNode::construct(_tcx, DepKind::$variant, &())
-                }
-            )*
-        }
-
         fn dep_kind_from_label_string(label: &str) -> Result<DepKind, ()> {
             match label {
                 $(stringify!($variant) => Ok(DepKind::$variant),)*
@@ -384,9 +358,16 @@ rustc_dep_node_append!([define_dep_nodes!][ <'tcx>
 
     [anon] TraitSelect,
 
+    // WARNING: if `Symbol` is changed, make sure you update `make_compile_codegen_unit` below.
     [] CompileCodegenUnit(Symbol),
 ]);
 
+// WARNING: `construct` is generic and does not know that `CompileCodegenUnit` takes `Symbol`s as keys.
+// Be very careful changing this type signature!
+crate fn make_compile_codegen_unit(tcx: TyCtxt<'_>, name: Symbol) -> DepNode {
+    DepNode::construct(tcx, DepKind::CompileCodegenUnit, &name)
+}
+
 pub type DepNode = rustc_query_system::dep_graph::DepNode<DepKind>;
 
 // We keep a lot of `DepNode`s in memory during compilation. It's not

compiler/rustc_middle/src/dep_graph/mod.rs

@@ -13,7 +13,8 @@ pub use rustc_query_system::dep_graph::{
     WorkProduct, WorkProductId,
 };
 
-pub use dep_node::{dep_constructor, label_strs, DepKind, DepNode, DepNodeExt};
+crate use dep_node::make_compile_codegen_unit;
+pub use dep_node::{label_strs, DepKind, DepNode, DepNodeExt};
 
 pub type DepGraph = rustc_query_system::dep_graph::DepGraph<DepKind>;
 pub type TaskDeps = rustc_query_system::dep_graph::TaskDeps<DepKind>;

compiler/rustc_middle/src/hir/map/mod.rs

@@ -813,7 +813,7 @@ impl<'hir> Map<'hir> {
     /// Given a node ID, gets a list of attributes associated with the AST
     /// corresponding to the node-ID.
     pub fn attrs(&self, id: HirId) -> &'hir [ast::Attribute] {
-        let attrs = self.find_entry(id).map(|entry| match entry.node {
+        self.find_entry(id).map_or(&[], |entry| match entry.node {
             Node::Param(a) => &a.attrs[..],
             Node::Local(l) => &l.attrs[..],
             Node::Item(i) => &i.attrs[..],
@@ -840,8 +840,7 @@ impl<'hir> Map<'hir> {
             | Node::Block(..)
             | Node::Lifetime(..)
             | Node::Visibility(..) => &[],
-        });
-        attrs.unwrap_or(&[])
+        })
     }
 
     /// Gets the span of the definition of the specified HIR node.

compiler/rustc_middle/src/mir/mono.rs

@@ -1,4 +1,4 @@
-use crate::dep_graph::{dep_constructor, DepNode, WorkProduct, WorkProductId};
+use crate::dep_graph::{DepNode, WorkProduct, WorkProductId};
 use crate::ich::{NodeIdHashingMode, StableHashingContext};
 use crate::ty::{subst::InternalSubsts, Instance, InstanceDef, SymbolName, TyCtxt};
 use rustc_attr::InlineAttr;
@@ -362,7 +362,7 @@ impl<'tcx> CodegenUnit<'tcx> {
     }
 
     pub fn codegen_dep_node(&self, tcx: TyCtxt<'tcx>) -> DepNode {
-        dep_constructor::CompileCodegenUnit(tcx, self.name())
+        crate::dep_graph::make_compile_codegen_unit(tcx, self.name())
     }
 }
 

compiler/rustc_middle/src/ty/consts/kind.rs

@@ -82,7 +82,7 @@ impl<'tcx> ConstKind<'tcx> {
     /// Tries to evaluate the constant if it is `Unevaluated`. If that doesn't succeed, return the
     /// unevaluated constant.
     pub fn eval(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> Self {
-        self.try_eval(tcx, param_env).and_then(Result::ok).map(ConstKind::Value).unwrap_or(self)
+        self.try_eval(tcx, param_env).and_then(Result::ok).map_or(self, ConstKind::Value)
     }
 
     #[inline]

compiler/rustc_middle/src/ty/context.rs

@@ -1338,7 +1338,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn serialize_query_result_cache(self, encoder: &mut FileEncoder) -> FileEncodeResult {
-        self.queries.on_disk_cache.as_ref().map(|c| c.serialize(self, encoder)).unwrap_or(Ok(()))
+        self.queries.on_disk_cache.as_ref().map_or(Ok(()), |c| c.serialize(self, encoder))
     }
 
     /// If `true`, we should use the MIR-based borrowck, but also
@@ -2601,7 +2601,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn is_late_bound(self, id: HirId) -> bool {
-        self.is_late_bound_map(id.owner).map(|set| set.contains(&id.local_id)).unwrap_or(false)
+        self.is_late_bound_map(id.owner).map_or(false, |set| set.contains(&id.local_id))
     }
 
     pub fn object_lifetime_defaults(self, id: HirId) -> Option<&'tcx [ObjectLifetimeDefault]> {