Merge rustc into rmc - 2021 week 40 (rust-lang#548)

.gitignore

@@ -69,8 +69,8 @@ __pycache__/
 *$py.class
 
 ## Node
-**node_modules
-**package-lock.json
+node_modules
+package-lock.json
 
 ## Rustdoc GUI tests
 src/test/rustdoc-gui/src/**.lock

.mailmap

@@ -72,6 +72,7 @@ Daniel Ramos <dan@daramos.com>
 David Klein <david.klein@baesystemsdetica.com>
 David Manescu <david.manescu@gmail.com> <dman2626@uni.sydney.edu.au>
 David Ross <daboross@daboross.net>
+David Wood <david@davidtw.co> <david.wood@huawei.com>
 Deadbeef <ent3rm4n@gmail.com> <fee1-dead-beef@protonmail.com>
 Derek Chiang <derekchiang93@gmail.com> Derek Chiang (Enchi Jiang) <derekchiang93@gmail.com>
 Diggory Hardy <diggory.hardy@gmail.com> Diggory Hardy <github@dhardy.name>

Cargo.lock

@@ -314,6 +314,7 @@ dependencies = [
  "num_cpus",
  "opener",
  "openssl",
+ "os_info",
  "percent-encoding 2.1.0",
  "pretty_env_logger",
  "rustc-workspace-hack",
@@ -908,9 +909,9 @@ dependencies = [
 
 [[package]]
 name = "curl"
-version = "0.4.38"
+version = "0.4.39"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "003cb79c1c6d1c93344c7e1201bb51c2148f24ec2bd9c253709d6b2efb796515"
+checksum = "aaa3b8db7f3341ddef15786d250106334d4a6c4b0ae4a46cd77082777d9849b9"
 dependencies = [
  "curl-sys",
  "libc",
@@ -923,9 +924,9 @@ dependencies = [
 
 [[package]]
 name = "curl-sys"
-version = "0.4.48+curl-7.79.1"
+version = "0.4.49+curl-7.79.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6a77a741f832116da66aeb126b4f19190ecf46144a74a9bde43c2086f38da0e"
+checksum = "e0f44960aea24a786a46907b8824ebc0e66ca06bf4e4978408c7499620343483"
 dependencies = [
  "cc",
  "libc",
@@ -1480,9 +1481,9 @@ dependencies = [
 
 [[package]]
 name = "git2"
-version = "0.13.17"
+version = "0.13.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d250f5f82326884bd39c2853577e70a121775db76818ffa452ed1e80de12986"
+checksum = "2a8057932925d3a9d9e4434ea016570d37420ddb1ceed45a174d577f24ed6700"
 dependencies = [
  "bitflags",
  "libc",
@@ -1932,18 +1933,18 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.99"
+version = "0.2.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7f823d141fe0a24df1e23b4af4e3c7ba9e5966ec514ea068c93024aa7deb765"
+checksum = "dd8f7255a17a627354f321ef0055d63b898c6fb27eff628af4d1b66b7331edf6"
 dependencies = [
  "rustc-std-workspace-core",
 ]
 
 [[package]]
 name = "libgit2-sys"
-version = "0.12.18+1.1.0"
+version = "0.12.24+1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3da6a42da88fc37ee1ecda212ffa254c25713532980005d5f7c0b0fbe7e6e885"
+checksum = "ddbd6021eef06fb289a8f54b3c2acfdd85ff2a585dfbb24b8576325373d2152c"
 dependencies = [
  "cc",
  "libc",
@@ -2018,6 +2019,10 @@ dependencies = [
  "walkdir",
 ]
 
+[[package]]
+name = "lld-wrapper"
+version = "0.1.0"
+
 [[package]]
 name = "lock_api"
 version = "0.4.1"
@@ -2513,6 +2518,17 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd20eec3dbe4376829cb7d80ae6ac45e0a766831dca50202ff2d40db46a8a024"
 
+[[package]]
+name = "os_info"
+version = "3.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ac91020bfed8cc3f8aa450d4c3b5fa1d3373fc091c8a92009f3b27749d5a227"
+dependencies = [
+ "log",
+ "serde",
+ "winapi",
+]
+
 [[package]]
 name = "output_vt100"
 version = "0.1.2"
@@ -4597,6 +4613,7 @@ dependencies = [
  "rustc_hir",
  "rustc_index",
  "rustc_infer",
+ "rustc_lint_defs",
  "rustc_macros",
  "rustc_middle",
  "rustc_parse_format",

Cargo.toml

@@ -37,6 +37,7 @@ members = [
   "src/tools/jsondocck",
   "src/tools/html-checker",
   "src/tools/bump-stage0",
+  "src/tools/lld-wrapper",
 ]
 
 exclude = [
@@ -91,6 +92,15 @@ gimli.debug = 0
 miniz_oxide.debug = 0
 object.debug = 0
 
+# The only package that ever uses debug builds is bootstrap.
+# We care a lot about bootstrap's compile times, so don't include debug info for
+# dependencies, only bootstrap itself.
+[profile.dev]
+debug = 0
+[profile.dev.package]
+# Only use debuginfo=1 to further reduce compile times.
+bootstrap.debug = 1
+
 # We want the RLS to use the version of Cargo that we've got vendored in this
 # repository to ensure that the same exact version of Cargo is used by both the
 # RLS and the Cargo binary itself. The RLS depends on Cargo as a git repository

UPSTREAM-RELEASES.md

@@ -64,7 +64,6 @@ Stabilised APIs
 - [`VecDeque::shrink_to`]
 - [`HashMap::shrink_to`]
 - [`HashSet::shrink_to`]
-- [`task::ready!`]
 
 These APIs are now usable in const contexts:
 
@@ -128,7 +127,6 @@ and related tools.
 [`VecDeque::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.shrink_to
 [`HashMap::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_map/struct.HashMap.html#method.shrink_to
 [`HashSet::shrink_to`]: https://doc.rust-lang.org/stable/std/collections/hash_set/struct.HashSet.html#method.shrink_to
-[`task::ready!`]: https://doc.rust-lang.org/stable/std/task/macro.ready.html
 [`std::mem::transmute`]: https://doc.rust-lang.org/stable/std/mem/fn.transmute.html
 [`slice::first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first
 [`slice::split_first`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_first

compiler/rustc_apfloat/src/ieee.rs

@@ -389,6 +389,7 @@ impl<S: Semantics> fmt::Display for IeeeFloat<S> {
         let _: Loss = sig::shift_right(&mut sig, &mut exp, trailing_zeros as usize);
 
         // Change the exponent from 2^e to 10^e.
+        #[allow(clippy::comparison_chain)]
         if exp == 0 {
             // Nothing to do.
         } else if exp > 0 {
@@ -2526,6 +2527,7 @@ mod sig {
         if *a_sign ^ b_sign {
             let (reverse, loss);
 
+            #[allow(clippy::comparison_chain)]
             if bits == 0 {
                 reverse = cmp(a_sig, b_sig) == Ordering::Less;
                 loss = Loss::ExactlyZero;

compiler/rustc_ast/src/lib.rs

@@ -20,16 +20,6 @@
 #[macro_use]
 extern crate rustc_macros;
 
-#[macro_export]
-macro_rules! unwrap_or {
-    ($opt:expr, $default:expr) => {
-        match $opt {
-            Some(x) => x,
-            None => $default,
-        }
-    };
-}
-
 pub mod util {
     pub mod classify;
     pub mod comments;

compiler/rustc_ast_lowering/src/asm.rs

@@ -202,39 +202,20 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
         let mut used_input_regs = FxHashMap::default();
         let mut used_output_regs = FxHashMap::default();
-        let mut required_features: Vec<&str> = vec![];
+
         for (idx, &(ref op, op_sp)) in operands.iter().enumerate() {
             if let Some(reg) = op.reg() {
-                // Make sure we don't accidentally carry features from the
-                // previous iteration.
-                required_features.clear();
-
                 let reg_class = reg.reg_class();
                 if reg_class == asm::InlineAsmRegClass::Err {
                     continue;
                 }
 
-                // We ignore target feature requirements for clobbers: if the
-                // feature is disabled then the compiler doesn't care what we
-                // do with the registers.
-                //
-                // Note that this is only possible for explicit register
-                // operands, which cannot be used in the asm string.
-                let is_clobber = matches!(
-                    op,
-                    hir::InlineAsmOperand::Out {
-                        reg: asm::InlineAsmRegOrRegClass::Reg(_),
-                        late: _,
-                        expr: None
-                    }
-                );
-
                 // Some register classes can only be used as clobbers. This
                 // means that we disallow passing a value in/out of the asm and
                 // require that the operand name an explicit register, not a
                 // register class.
                 if reg_class.is_clobber_only(asm_arch.unwrap())
-                    && !(is_clobber && matches!(reg, asm::InlineAsmRegOrRegClass::Reg(_)))
+                    && !(op.is_clobber() && matches!(reg, asm::InlineAsmRegOrRegClass::Reg(_)))
                 {
                     let msg = format!(
                         "register class `{}` can only be used as a clobber, \
@@ -245,47 +226,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     continue;
                 }
 
-                if !is_clobber {
-                    // Validate register classes against currently enabled target
-                    // features. We check that at least one type is available for
-                    // the current target.
-                    for &(_, feature) in reg_class.supported_types(asm_arch.unwrap()) {
-                        if let Some(feature) = feature {
-                            if self.sess.target_features.contains(&Symbol::intern(feature)) {
-                                required_features.clear();
-                                break;
-                            } else {
-                                required_features.push(feature);
-                            }
-                        } else {
-                            required_features.clear();
-                            break;
-                        }
-                    }
-                    // We are sorting primitive strs here and can use unstable sort here
-                    required_features.sort_unstable();
-                    required_features.dedup();
-                    match &required_features[..] {
-                        [] => {}
-                        [feature] => {
-                            let msg = format!(
-                                "register class `{}` requires the `{}` target feature",
-                                reg_class.name(),
-                                feature
-                            );
-                            sess.struct_span_err(op_sp, &msg).emit();
-                        }
-                        features => {
-                            let msg = format!(
-                                "register class `{}` requires at least one target feature: {}",
-                                reg_class.name(),
-                                features.join(", ")
-                            );
-                            sess.struct_span_err(op_sp, &msg).emit();
-                        }
-                    }
-                }
-
                 // Check for conflicts between explicit register operands.
                 if let asm::InlineAsmRegOrRegClass::Reg(reg) = reg {
                     let (input, output) = match op {

compiler/rustc_ast_lowering/src/item.rs

@@ -1345,8 +1345,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         generics
                             .params
                             .iter()
-                            .find(|p| def_id == self.resolver.local_def_id(p.id).to_def_id())
-                            .is_some()
+                            .any(|p| def_id == self.resolver.local_def_id(p.id).to_def_id())
                     }
                     // Either the `bounded_ty` is not a plain type parameter, or
                     // it's not found in the generic type parameters list.

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -279,6 +279,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
 
                 gate_doc!(
                     cfg => doc_cfg
+                    cfg_hide => doc_cfg_hide
                     masked => doc_masked
                     notable_trait => doc_notable_trait
                     keyword => doc_keyword

compiler/rustc_borrowck/src/consumers.rs

@@ -31,7 +31,7 @@ pub fn get_body_with_borrowck_facts<'tcx>(
     def: ty::WithOptConstParam<LocalDefId>,
 ) -> BodyWithBorrowckFacts<'tcx> {
     let (input_body, promoted) = tcx.mir_promoted(def);
-    tcx.infer_ctxt().enter(|infcx| {
+    tcx.infer_ctxt().with_opaque_type_inference(def.did).enter(|infcx| {
         let input_body: &Body<'_> = &input_body.borrow();
         let promoted: &IndexVec<_, _> = &promoted.borrow();
         *super::do_mir_borrowck(&infcx, input_body, promoted, true).1.unwrap()

compiler/rustc_borrowck/src/dataflow.rs

@@ -201,7 +201,7 @@ impl<'tcx> OutOfScopePrecomputer<'_, 'tcx> {
                 let bb_data = &self.body[bb];
                 debug_assert!(hi == bb_data.statements.len());
                 for &succ_bb in bb_data.terminator().successors() {
-                    if self.visited.insert(succ_bb) == false {
+                    if !self.visited.insert(succ_bb) {
                         if succ_bb == location.block && first_lo > 0 {
                             // `succ_bb` has been seen before. If it wasn't
                             // fully processed, add its first part to `stack`

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -972,8 +972,7 @@ fn suggest_ampmut<'tcx>(
     if let Some(assignment_rhs_span) = opt_assignment_rhs_span {
         if let Ok(src) = tcx.sess.source_map().span_to_snippet(assignment_rhs_span) {
             let is_mutbl = |ty: &str| -> bool {
-                if ty.starts_with("mut") {
-                    let rest = &ty[3..];
+                if let Some(rest) = ty.strip_prefix("mut") {
                     match rest.chars().next() {
                         // e.g. `&mut x`
                         Some(c) if c.is_whitespace() => true,

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -498,6 +498,27 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             diag.span_label(*span, format!("`{}` escapes the {} body here", fr_name, escapes_from));
         }
 
+        // Only show an extra note if we can find an 'error region' for both of the region
+        // variables. This avoids showing a noisy note that just mentions 'synthetic' regions
+        // that don't help the user understand the error.
+        if self.to_error_region(errci.fr).is_some()
+            && self.to_error_region(errci.outlived_fr).is_some()
+        {
+            let fr_region_name = self.give_region_a_name(errci.fr).unwrap();
+            fr_region_name.highlight_region_name(&mut diag);
+            let outlived_fr_region_name = self.give_region_a_name(errci.outlived_fr).unwrap();
+            outlived_fr_region_name.highlight_region_name(&mut diag);
+
+            diag.span_label(
+                *span,
+                format!(
+                    "{}requires that `{}` must outlive `{}`",
+                    category.description(),
+                    fr_region_name,
+                    outlived_fr_region_name,
+                ),
+            );
+        }
         diag
     }
 

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1153,28 +1153,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         .convert_all(data);
     }
 
-    /// Convenient wrapper around `relate_tys::relate_types` -- see
-    /// that fn for docs.
-    fn relate_types(
-        &mut self,
-        a: Ty<'tcx>,
-        v: ty::Variance,
-        b: Ty<'tcx>,
-        locations: Locations,
-        category: ConstraintCategory,
-    ) -> Fallible<()> {
-        relate_tys::relate_types(
-            self.infcx,
-            self.param_env,
-            a,
-            v,
-            b,
-            locations,
-            category,
-            self.borrowck_context,
-        )
-    }
-
     /// Try to relate `sub <: sup`
     fn sub_types(
         &mut self,