Auto merge of rust-lang#70726 - Centril:rollup-zrdkkpt, r=Centril

Rollup of 5 pull requests

Successful merges:

 - rust-lang#68334 (AArch64 bare-metal targets: Build rust-std)
 - rust-lang#70224 (Clean up rustdoc js testers)
 - rust-lang#70532 (Miri engine: stronger type-based sanity check for assignments)
 - rust-lang#70698 (bootstrap: add `--json-output` for rust-analyzer)
 - rust-lang#70715 (Fix typo in operands section)

Failed merges:

r? @ghost

src/bootstrap/compile.rs

@@ -935,7 +935,11 @@ pub fn stream_cargo(
     }
     // Instruct Cargo to give us json messages on stdout, critically leaving
     // stderr as piped so we can get those pretty colors.
-    let mut message_format = String::from("json-render-diagnostics");
+    let mut message_format = if builder.config.json_output {
+        String::from("json")
+    } else {
+        String::from("json-render-diagnostics")
+    };
     if let Some(s) = &builder.config.rustc_error_format {
         message_format.push_str(",json-diagnostic-");
         message_format.push_str(s);

src/bootstrap/config.rs

@@ -48,6 +48,7 @@ pub struct Config {
     pub ignore_git: bool,
     pub exclude: Vec<PathBuf>,
     pub rustc_error_format: Option<String>,
+    pub json_output: bool,
     pub test_compare_mode: bool,
     pub llvm_libunwind: bool,
 
@@ -415,6 +416,7 @@ impl Config {
         let mut config = Config::default_opts();
         config.exclude = flags.exclude;
         config.rustc_error_format = flags.rustc_error_format;
+        config.json_output = flags.json_output;
         config.on_fail = flags.on_fail;
         config.stage = flags.stage;
         config.jobs = flags.jobs.map(threads_from_config);

src/bootstrap/flags.rs

@@ -31,6 +31,7 @@ pub struct Flags {
     pub incremental: bool,
     pub exclude: Vec<PathBuf>,
     pub rustc_error_format: Option<String>,
+    pub json_output: bool,
     pub dry_run: bool,
 
     // This overrides the deny-warnings configuration option,
@@ -156,6 +157,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`",
             "VALUE",
         );
         opts.optopt("", "error-format", "rustc error format", "FORMAT");
+        opts.optflag("", "json-output", "use message-format=json");
         opts.optopt(
             "",
             "llvm-skip-rebuild",
@@ -503,6 +505,7 @@ Arguments:
             dry_run: matches.opt_present("dry-run"),
             on_fail: matches.opt_str("on-fail"),
             rustc_error_format: matches.opt_str("error-format"),
+            json_output: matches.opt_present("json-output"),
             keep_stage: matches
                 .opt_strs("keep-stage")
                 .into_iter()

src/ci/docker/dist-various-1/Dockerfile

@@ -72,6 +72,9 @@ RUN ./install-mips-musl.sh
 COPY dist-various-1/install-mipsel-musl.sh /build
 RUN ./install-mipsel-musl.sh
 
+COPY dist-various-1/install-aarch64-none-elf.sh /build
+RUN ./install-aarch64-none-elf.sh
+
 # Suppress some warnings in the openwrt toolchains we downloaded
 ENV STAGING_DIR=/tmp
 
@@ -140,6 +143,8 @@ ENV TARGETS=$TARGETS,armv5te-unknown-linux-gnueabi
 ENV TARGETS=$TARGETS,armv5te-unknown-linux-musleabi
 ENV TARGETS=$TARGETS,armv7-unknown-linux-musleabihf
 ENV TARGETS=$TARGETS,aarch64-unknown-linux-musl
+ENV TARGETS=$TARGETS,aarch64-unknown-none
+ENV TARGETS=$TARGETS,aarch64-unknown-none-softfloat
 ENV TARGETS=$TARGETS,sparc64-unknown-linux-gnu
 ENV TARGETS=$TARGETS,x86_64-unknown-redox
 ENV TARGETS=$TARGETS,thumbv6m-none-eabi
@@ -178,6 +183,10 @@ ENV CC_mipsel_unknown_linux_musl=mipsel-openwrt-linux-gcc \
     CC_armv7a_none_eabihf=arm-none-eabi-gcc \
     CFLAGS_armv7a_none_eabi=-march=armv7-a \
     CFLAGS_armv7a_none_eabihf=-march=armv7-a+vfpv3 \
+    CC_aarch64_unknown_none_softfloat=aarch64-none-elf-gcc \
+    CFLAGS_aarch64_unknown_none_softfloat=-mstrict-align -march=armv8-a+nofp+nosimd \
+    CC_aarch64_unknown_none=aarch64-none-elf-gcc \
+    CFLAGS_aarch64_unknown_none=-mstrict-align -march=armv8-a+fp+simd \
     CC_riscv64gc_unknown_linux_gnu=riscv64-unknown-linux-gnu-gcc \
     AR_riscv64gc_unknown_linux_gnu=riscv64-unknown-linux-gnu-ar \
     CXX_riscv64gc_unknown_linux_gnu=riscv64-unknown-linux-gnu-g++ \

src/ci/docker/dist-various-1/install-aarch64-none-elf.sh

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+set -ex
+
+curl -L https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/gcc-arm-9.2-2019.12-x86_64-aarch64-none-elf.tar.xz \
+| tar --extract --xz --strip 1 --directory /usr/local

src/doc/unstable-book/src/library-features/llvm-asm.md

@@ -86,7 +86,7 @@ llvm_asm!("xor %eax, %eax" ::: "eax");
 
 Input and output operands follow the same format: `:
 "constraints1"(expr1), "constraints2"(expr2), ..."`. Output operand
-expressions must be mutable lvalues, or not yet assigned:
+expressions must be mutable place, or not yet assigned:
 
 ```rust
 # #![feature(llvm_asm)]

src/librustc_mir/interpret/eval_context.rs

@@ -18,7 +18,7 @@ use rustc_middle::ty::query::TyCtxtAt;
 use rustc_middle::ty::subst::SubstsRef;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
 use rustc_span::source_map::DUMMY_SP;
-use rustc_target::abi::{Align, HasDataLayout, LayoutOf, Size, TargetDataLayout};
+use rustc_target::abi::{Abi, Align, HasDataLayout, LayoutOf, Size, TargetDataLayout};
 
 use super::{
     Immediate, MPlaceTy, Machine, MemPlace, MemPlaceMeta, Memory, OpTy, Operand, Place, PlaceTy,
@@ -210,6 +210,53 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> LayoutOf for InterpCx<'mir, 'tcx, M> {
     }
 }
 
+/// Test if it is valid for a MIR assignment to assign `src`-typed place to `dest`-typed value.
+/// This test should be symmetric, as it is primarily about layout compatibility.
+pub(super) fn mir_assign_valid_types<'tcx>(
+    src: TyAndLayout<'tcx>,
+    dest: TyAndLayout<'tcx>,
+) -> bool {
+    if src.ty == dest.ty {
+        // Equal types, all is good.
+        return true;
+    }
+    // Type-changing assignments can happen for (at least) two reasons:
+    // - `&mut T` -> `&T` gets optimized from a reborrow to a mere assignment.
+    // - Subtyping is used. While all normal lifetimes are erased, higher-ranked lifetime
+    //   bounds are still around and can lead to type differences.
+    // There is no good way to check the latter, so we compare layouts instead -- but only
+    // for values with `Scalar`/`ScalarPair` abi.
+    // FIXME: Do something more accurate, type-based.
+    match &src.abi {
+        Abi::Scalar(..) | Abi::ScalarPair(..) => src.layout == dest.layout,
+        _ => false,
+    }
+}
+
+/// Use the already known layout if given (but sanity check in debug mode),
+/// or compute the layout.
+#[cfg_attr(not(debug_assertions), inline(always))]
+pub(super) fn from_known_layout<'tcx>(
+    known_layout: Option<TyAndLayout<'tcx>>,
+    compute: impl FnOnce() -> InterpResult<'tcx, TyAndLayout<'tcx>>,
+) -> InterpResult<'tcx, TyAndLayout<'tcx>> {
+    match known_layout {
+        None => compute(),
+        Some(known_layout) => {
+            if cfg!(debug_assertions) {
+                let check_layout = compute()?;
+                assert!(
+                    mir_assign_valid_types(check_layout, known_layout),
+                    "expected type differs from actual type.\nexpected: {:?}\nactual: {:?}",
+                    known_layout.ty,
+                    check_layout.ty,
+                );
+            }
+            Ok(known_layout)
+        }
+    }
+}
+
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     pub fn new(
         tcx: TyCtxtAt<'tcx>,
@@ -377,7 +424,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // have to support that case (mostly by skipping all caching).
         match frame.locals.get(local).and_then(|state| state.layout.get()) {
             None => {
-                let layout = crate::interpret::operand::from_known_layout(layout, || {
+                let layout = from_known_layout(layout, || {
                     let local_ty = frame.body.local_decls[local].ty;
                     let local_ty =
                         self.subst_from_frame_and_normalize_erasing_regions(frame, local_ty);

src/librustc_mir/interpret/mod.rs

@@ -18,19 +18,13 @@ mod visitor;
 pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in one place: here
 
 pub use self::eval_context::{Frame, InterpCx, LocalState, LocalValue, StackPopCleanup};
-
-pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy};
-
-pub use self::memory::{AllocCheck, FnVal, Memory, MemoryKind};
-
+pub use self::intern::{intern_const_alloc_recursive, InternKind};
 pub use self::machine::{AllocMap, Machine, MayLeak, StackPopJump};
-
-pub use self::operand::{ImmTy, Immediate, OpTy, Operand, ScalarMaybeUndef};
-
-pub use self::visitor::{MutValueVisitor, ValueVisitor};
-
+pub use self::memory::{AllocCheck, FnVal, Memory, MemoryKind};
+pub use self::operand::{ImmTy, Immediate, OpTy, Operand};
+pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy};
 pub use self::validity::RefTracking;
-
-pub use self::intern::{intern_const_alloc_recursive, InternKind};
+pub use self::visitor::{MutValueVisitor, ValueVisitor};
 
 crate use self::intrinsics::eval_nullary_intrinsic;
+use eval_context::{from_known_layout, mir_assign_valid_types};

src/librustc_mir/interpret/operand.rs

@@ -2,21 +2,21 @@
 //! All high-level functions to read from memory work on operands as sources.
 
 use std::convert::TryFrom;
+use std::fmt::Write;
 
-use super::{InterpCx, MPlaceTy, Machine, MemPlace, Place, PlaceTy};
 use rustc_hir::def::Namespace;
 use rustc_macros::HashStable;
-pub use rustc_middle::mir::interpret::ScalarMaybeUndef;
-use rustc_middle::mir::interpret::{
-    sign_extend, truncate, AllocId, ConstValue, GlobalId, InterpResult, Pointer, Scalar,
-};
 use rustc_middle::ty::layout::{IntegerExt, PrimitiveExt, TyAndLayout};
 use rustc_middle::ty::print::{FmtPrinter, PrettyPrinter, Printer};
 use rustc_middle::ty::Ty;
 use rustc_middle::{mir, ty};
 use rustc_target::abi::{Abi, DiscriminantKind, HasDataLayout, Integer, LayoutOf, Size};
 use rustc_target::abi::{VariantIdx, Variants};
-use std::fmt::Write;
+
+use super::{
+    from_known_layout, sign_extend, truncate, AllocId, ConstValue, GlobalId, InterpCx,
+    InterpResult, MPlaceTy, Machine, MemPlace, Place, PlaceTy, Pointer, Scalar, ScalarMaybeUndef,
+};
 
 /// An `Immediate` represents a single immediate self-contained Rust value.
 ///
@@ -203,29 +203,6 @@ impl<'tcx, Tag: Copy> ImmTy<'tcx, Tag> {
     }
 }
 
-// Use the existing layout if given (but sanity check in debug mode),
-// or compute the layout.
-#[inline(always)]
-pub(super) fn from_known_layout<'tcx>(
-    layout: Option<TyAndLayout<'tcx>>,
-    compute: impl FnOnce() -> InterpResult<'tcx, TyAndLayout<'tcx>>,
-) -> InterpResult<'tcx, TyAndLayout<'tcx>> {
-    match layout {
-        None => compute(),
-        Some(layout) => {
-            if cfg!(debug_assertions) {
-                let layout2 = compute()?;
-                assert_eq!(
-                    layout.layout, layout2.layout,
-                    "mismatch in layout of supposedly equal-layout types {:?} and {:?}",
-                    layout.ty, layout2.ty
-                );
-            }
-            Ok(layout)
-        }
-    }
-}
-
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     /// Normalice `place.ptr` to a `Pointer` if this is a place and not a ZST.
     /// Can be helpful to avoid lots of `force_ptr` calls later, if this place is used a lot.

src/librustc_mir/interpret/place.rs

@@ -7,16 +7,15 @@ use std::hash::Hash;
 
 use rustc_macros::HashStable;
 use rustc_middle::mir;
-use rustc_middle::mir::interpret::truncate;
 use rustc_middle::ty::layout::{PrimitiveExt, TyAndLayout};
 use rustc_middle::ty::{self, Ty};
 use rustc_target::abi::{Abi, Align, DiscriminantKind, FieldsShape};
 use rustc_target::abi::{HasDataLayout, LayoutOf, Size, VariantIdx, Variants};
 
 use super::{
-    AllocId, AllocMap, Allocation, AllocationExtra, ImmTy, Immediate, InterpCx, InterpResult,
-    LocalValue, Machine, MemoryKind, OpTy, Operand, Pointer, PointerArithmetic, RawConst, Scalar,
-    ScalarMaybeUndef,
+    mir_assign_valid_types, truncate, AllocId, AllocMap, Allocation, AllocationExtra, ImmTy,
+    Immediate, InterpCx, InterpResult, LocalValue, Machine, MemoryKind, OpTy, Operand, Pointer,
+    PointerArithmetic, RawConst, Scalar, ScalarMaybeUndef,
 };
 
 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, HashStable)]
@@ -869,10 +868,10 @@ where
         // We do NOT compare the types for equality, because well-typed code can
         // actually "transmute" `&mut T` to `&T` in an assignment without a cast.
         assert!(
-            src.layout.layout == dest.layout.layout,
-            "Layout mismatch when copying!\nsrc: {:#?}\ndest: {:#?}",
-            src,
-            dest
+            mir_assign_valid_types(src.layout, dest.layout),
+            "type mismatch when copying!\nsrc: {:?},\ndest: {:?}",
+            src.layout.ty,
+            dest.layout.ty,
         );
 
         // Let us see if the layout is simple so we take a shortcut, avoid force_allocation.
@@ -923,7 +922,7 @@ where
         src: OpTy<'tcx, M::PointerTag>,
         dest: PlaceTy<'tcx, M::PointerTag>,
     ) -> InterpResult<'tcx> {
-        if src.layout.layout == dest.layout.layout {
+        if mir_assign_valid_types(src.layout, dest.layout) {
             // Fast path: Just use normal `copy_op`
             return self.copy_op(src, dest);
         }

src/tools/build-manifest/src/main.rs

@@ -56,6 +56,8 @@ static TARGETS: &[&str] = &[
     "aarch64-unknown-hermit",
     "aarch64-unknown-linux-gnu",
     "aarch64-unknown-linux-musl",
+    "aarch64-unknown-none",
+    "aarch64-unknown-none-softfloat",
     "aarch64-unknown-redox",
     "arm-linux-androideabi",
     "arm-unknown-linux-gnueabi",