Auto merge of #122206 - matthiaskrgr:rollup-4txx9wx, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #121201 (align_offset, align_to: no longer allow implementations to spuriously fail to align)
 - #122076 (Tweak the way we protect in-place function arguments in interpreters)
 - #122100 (Better comment for implicit captures in RPITIT)
 - #122157 (Add the new description field to Target::to_json, and add descriptions for some MSVC targets)
 - #122164 (Fix misaligned loads when loading UEFI arg pointers)
 - #122171 (Add some new solver tests)
 - #122172 (Don't ICE if we collect no RPITITs unless there are no unification errors)
 - #122197 (inspect formatter: add braces)
 - #122198 (Remove handling for previously dropped LLVM version)

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

Author: bors

compiler/rustc_codegen_llvm/src/context.rs

@@ -260,35 +260,29 @@ pub unsafe fn create_module<'ll>(
     }
 
     if let Some(BranchProtection { bti, pac_ret }) = sess.opts.unstable_opts.branch_protection {
-        let behavior = if llvm_version >= (15, 0, 0) {
-            llvm::LLVMModFlagBehavior::Min
-        } else {
-            llvm::LLVMModFlagBehavior::Error
-        };
-
         if sess.target.arch == "aarch64" {
             llvm::LLVMRustAddModuleFlag(
                 llmod,
-                behavior,
+                llvm::LLVMModFlagBehavior::Min,
                 c"branch-target-enforcement".as_ptr().cast(),
                 bti.into(),
             );
             llvm::LLVMRustAddModuleFlag(
                 llmod,
-                behavior,
+                llvm::LLVMModFlagBehavior::Min,
                 c"sign-return-address".as_ptr().cast(),
                 pac_ret.is_some().into(),
             );
             let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, key: PAuthKey::A });
             llvm::LLVMRustAddModuleFlag(
                 llmod,
-                behavior,
+                llvm::LLVMModFlagBehavior::Min,
                 c"sign-return-address-all".as_ptr().cast(),
                 pac_opts.leaf.into(),
             );
             llvm::LLVMRustAddModuleFlag(
                 llmod,
-                behavior,
+                llvm::LLVMModFlagBehavior::Min,
                 c"sign-return-address-with-bkey".as_ptr().cast(),
                 u32::from(pac_opts.key == PAuthKey::B),
             );

compiler/rustc_codegen_ssa/src/base.rs

@@ -510,11 +510,13 @@ fn get_argc_argv<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         // Params for UEFI
         let param_handle = bx.get_param(0);
         let param_system_table = bx.get_param(1);
+        let ptr_size = bx.tcx().data_layout.pointer_size;
+        let ptr_align = bx.tcx().data_layout.pointer_align.abi;
         let arg_argc = bx.const_int(cx.type_isize(), 2);
-        let arg_argv = bx.alloca(cx.type_array(cx.type_ptr(), 2), Align::ONE);
-        bx.store(param_handle, arg_argv, Align::ONE);
-        let arg_argv_el1 = bx.gep(cx.type_ptr(), arg_argv, &[bx.const_int(cx.type_int(), 1)]);
-        bx.store(param_system_table, arg_argv_el1, Align::ONE);
+        let arg_argv = bx.alloca(cx.type_array(cx.type_ptr(), 2), ptr_align);
+        bx.store(param_handle, arg_argv, ptr_align);
+        let arg_argv_el1 = bx.inbounds_ptradd(arg_argv, bx.const_usize(ptr_size.bytes()));
+        bx.store(param_system_table, arg_argv_el1, ptr_align);
         (arg_argc, arg_argv)
     } else if cx.sess().target.main_needs_argc_argv {
         // Params from native `main()` used as args for rust start function

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -227,7 +227,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
         if self.tcx.has_attr(def_id, sym::rustc_const_panic_str)
             || Some(def_id) == self.tcx.lang_items().begin_panic_fn()
         {
-            let args = self.copy_fn_args(args)?;
+            let args = self.copy_fn_args(args);
             // &str or &&str
             assert!(args.len() == 1);
 
@@ -254,7 +254,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
 
             return Ok(Some(new_instance));
         } else if Some(def_id) == self.tcx.lang_items().align_offset_fn() {
-            let args = self.copy_fn_args(args)?;
+            let args = self.copy_fn_args(args);
             // For align_offset, we replace the function call if the pointer has no address.
             match self.align_offset(instance, &args, dest, ret)? {
                 ControlFlow::Continue(()) => return Ok(Some(instance)),

compiler/rustc_const_eval/src/interpret/machine.rs

@@ -472,11 +472,11 @@ pub trait Machine<'mir, 'tcx: 'mir>: Sized {
     /// argument/return value was actually copied or passed in-place..
     fn protect_in_place_function_argument(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
-        place: &PlaceTy<'tcx, Self::Provenance>,
+        mplace: &MPlaceTy<'tcx, Self::Provenance>,
     ) -> InterpResult<'tcx> {
         // Without an aliasing model, all we can do is put `Uninit` into the place.
         // Conveniently this also ensures that the place actually points to suitable memory.
-        ecx.write_uninit(place)
+        ecx.write_uninit(mplace)
     }
 
     /// Called immediately before a new stack frame gets pushed.

compiler/rustc_const_eval/src/interpret/terminator.rs

@@ -1,5 +1,7 @@
 use std::borrow::Cow;
 
+use either::Either;
+
 use rustc_middle::{
     mir,
     ty::{
@@ -29,28 +31,25 @@ pub enum FnArg<'tcx, Prov: Provenance = CtfeProvenance> {
     Copy(OpTy<'tcx, Prov>),
     /// Allow for the argument to be passed in-place: destroy the value originally stored at that place and
     /// make the place inaccessible for the duration of the function call.
-    InPlace(PlaceTy<'tcx, Prov>),
+    InPlace(MPlaceTy<'tcx, Prov>),
 }
 
 impl<'tcx, Prov: Provenance> FnArg<'tcx, Prov> {
     pub fn layout(&self) -> &TyAndLayout<'tcx> {
         match self {
             FnArg::Copy(op) => &op.layout,
-            FnArg::InPlace(place) => &place.layout,
+            FnArg::InPlace(mplace) => &mplace.layout,
         }
     }
 }
 
 impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     /// Make a copy of the given fn_arg. Any `InPlace` are degenerated to copies, no protection of the
     /// original memory occurs.
-    pub fn copy_fn_arg(
-        &self,
-        arg: &FnArg<'tcx, M::Provenance>,
-    ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> {
+    pub fn copy_fn_arg(&self, arg: &FnArg<'tcx, M::Provenance>) -> OpTy<'tcx, M::Provenance> {
         match arg {
-            FnArg::Copy(op) => Ok(op.clone()),
-            FnArg::InPlace(place) => self.place_to_op(place),
+            FnArg::Copy(op) => op.clone(),
+            FnArg::InPlace(mplace) => mplace.clone().into(),
         }
     }
 
@@ -59,7 +58,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     pub fn copy_fn_args(
         &self,
         args: &[FnArg<'tcx, M::Provenance>],
-    ) -> InterpResult<'tcx, Vec<OpTy<'tcx, M::Provenance>>> {
+    ) -> Vec<OpTy<'tcx, M::Provenance>> {
         args.iter().map(|fn_arg| self.copy_fn_arg(fn_arg)).collect()
     }
 
@@ -70,7 +69,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ) -> InterpResult<'tcx, FnArg<'tcx, M::Provenance>> {
         Ok(match arg {
             FnArg::Copy(op) => FnArg::Copy(self.project_field(op, field)?),
-            FnArg::InPlace(place) => FnArg::InPlace(self.project_field(place, field)?),
+            FnArg::InPlace(mplace) => FnArg::InPlace(self.project_field(mplace, field)?),
         })
     }
 
@@ -238,10 +237,36 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
     ) -> InterpResult<'tcx, Vec<FnArg<'tcx, M::Provenance>>> {
         ops.iter()
             .map(|op| {
-                Ok(match &op.node {
-                    mir::Operand::Move(place) => FnArg::InPlace(self.eval_place(*place)?),
-                    _ => FnArg::Copy(self.eval_operand(&op.node, None)?),
-                })
+                let arg = match &op.node {
+                    mir::Operand::Copy(_) | mir::Operand::Constant(_) => {
+                        // Make a regular copy.
+                        let op = self.eval_operand(&op.node, None)?;
+                        FnArg::Copy(op)
+                    }
+                    mir::Operand::Move(place) => {
+                        // If this place lives in memory, preserve its location.
+                        // We call `place_to_op` which will be an `MPlaceTy` whenever there exists
+                        // an mplace for this place. (This is in contrast to `PlaceTy::as_mplace_or_local`
+                        // which can return a local even if that has an mplace.)
+                        let place = self.eval_place(*place)?;
+                        let op = self.place_to_op(&place)?;
+
+                        match op.as_mplace_or_imm() {
+                            Either::Left(mplace) => FnArg::InPlace(mplace),
+                            Either::Right(_imm) => {
+                                // This argument doesn't live in memory, so there's no place
+                                // to make inaccessible during the call.
+                                // We rely on there not being any stray `PlaceTy` that would let the
+                                // caller directly access this local!
+                                // This is also crucial for tail calls, where we want the `FnArg` to
+                                // stay valid when the old stack frame gets popped.
+                                FnArg::Copy(op)
+                            }
+                        }
+                    }
+                };
+
+                Ok(arg)
             })
             .collect()
     }
@@ -451,7 +476,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // We work with a copy of the argument for now; if this is in-place argument passing, we
         // will later protect the source it comes from. This means the callee cannot observe if we
         // did in-place of by-copy argument passing, except for pointer equality tests.
-        let caller_arg_copy = self.copy_fn_arg(caller_arg)?;
+        let caller_arg_copy = self.copy_fn_arg(caller_arg);
         if !already_live {
             let local = callee_arg.as_local().unwrap();
             let meta = caller_arg_copy.meta();
@@ -469,8 +494,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // specifically.)
         self.copy_op_allow_transmute(&caller_arg_copy, &callee_arg)?;
         // If this was an in-place pass, protect the place it comes from for the duration of the call.
-        if let FnArg::InPlace(place) = caller_arg {
-            M::protect_in_place_function_argument(self, place)?;
+        if let FnArg::InPlace(mplace) = caller_arg {
+            M::protect_in_place_function_argument(self, mplace)?;
         }
         Ok(())
     }
@@ -517,7 +542,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 M::call_intrinsic(
                     self,
                     instance,
-                    &self.copy_fn_args(args)?,
+                    &self.copy_fn_args(args),
                     destination,
                     target,
                     unwind,
@@ -594,8 +619,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                             .map(|arg| (
                                 arg.layout().ty,
                                 match arg {
-                                    FnArg::Copy(op) => format!("copy({:?})", *op),
-                                    FnArg::InPlace(place) => format!("in-place({:?})", *place),
+                                    FnArg::Copy(op) => format!("copy({op:?})"),
+                                    FnArg::InPlace(mplace) => format!("in-place({mplace:?})"),
                                 }
                             ))
                             .collect::<Vec<_>>()
@@ -717,8 +742,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                             callee_ty: callee_fn_abi.ret.layout.ty
                         });
                     }
+
                     // Protect return place for in-place return value passing.
-                    M::protect_in_place_function_argument(self, &destination.clone().into())?;
+                    M::protect_in_place_function_argument(self, &destination)?;
 
                     // Don't forget to mark "initially live" locals as live.
                     self.storage_live_for_always_live_locals()?;
@@ -741,7 +767,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 // An `InPlace` does nothing here, we keep the original receiver intact. We can't
                 // really pass the argument in-place anyway, and we are constructing a new
                 // `Immediate` receiver.
-                let mut receiver = self.copy_fn_arg(&args[0])?;
+                let mut receiver = self.copy_fn_arg(&args[0]);
                 let receiver_place = loop {
                     match receiver.layout.ty.kind() {
                         ty::Ref(..) | ty::RawPtr(..) => {

compiler/rustc_error_codes/src/error_codes/E0657.md

@@ -1,57 +1,26 @@
-A lifetime bound on a trait implementation was captured at an incorrect place.
+An `impl Trait` captured a higher-ranked lifetime, which is not supported.
+
+Currently, `impl Trait` types are only allowed to capture lifetimes from
+their parent items, and not from any `for<'a>` binders in scope.
 
 Erroneous code example:
 
 ```compile_fail,E0657
-trait Id<T> {}
-trait Lt<'a> {}
-
-impl<'a> Lt<'a> for () {}
-impl<T> Id<T> for T {}
-
-fn free_fn_capture_hrtb_in_impl_trait()
-    -> Box<for<'a> Id<impl Lt<'a>>> // error!
-{
-    Box::new(())
-}
+trait BorrowInto<'a> {
+    type Target;
 
-struct Foo;
-impl Foo {
-    fn impl_fn_capture_hrtb_in_impl_trait()
-        -> Box<for<'a> Id<impl Lt<'a>>> // error!
-    {
-        Box::new(())
-    }
+    fn borrow_into(&'a self) -> Self::Target;
 }
-```
 
-Here, you have used the inappropriate lifetime in the `impl Trait`,
-The `impl Trait` can only capture lifetimes bound at the fn or impl
-level.
+impl<'a> BorrowInto<'a> for () {
+    type Target = &'a ();
 
-To fix this we have to define the lifetime at the function or impl
-level and use that lifetime in the `impl Trait`. For example you can
-define the lifetime at the function:
-
-```
-trait Id<T> {}
-trait Lt<'a> {}
-
-impl<'a> Lt<'a> for () {}
-impl<T> Id<T> for T {}
-
-fn free_fn_capture_hrtb_in_impl_trait<'b>()
-    -> Box<for<'a> Id<impl Lt<'b>>> // ok!
-{
-    Box::new(())
+    fn borrow_into(&'a self) -> Self::Target {
+        self
+    }
 }
 
-struct Foo;
-impl Foo {
-    fn impl_fn_capture_hrtb_in_impl_trait<'b>()
-        -> Box<for<'a> Id<impl Lt<'b>>> // ok!
-    {
-        Box::new(())
-    }
+fn opaque() -> impl for<'a> BorrowInto<'a, Target = impl Sized + 'a> {
+    ()
 }
 ```

compiler/rustc_hir_analysis/messages.ftl

@@ -312,6 +312,10 @@ hir_analysis_only_current_traits_primitive = only traits defined in the current
 
 hir_analysis_only_current_traits_ty = `{$ty}` is not defined in the current crate
 
+hir_analysis_opaque_captures_higher_ranked_lifetime = `impl Trait` cannot capture {$bad_place}
+    .label = `impl Trait` implicitly captures all lifetimes in scope
+    .note = lifetime declared here
+
 hir_analysis_paren_sugar_attribute = the `#[rustc_paren_sugar]` attribute is a temporary means of controlling which traits can use parenthetical notation
     .help = add `#![feature(unboxed_closures)]` to the crate attributes to use it
 

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -521,14 +521,6 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
         )
         .fold_with(&mut collector);
 
-    if !unnormalized_trait_sig.output().references_error() {
-        debug_assert_ne!(
-            collector.types.len(),
-            0,
-            "expect >1 RPITITs in call to `collect_return_position_impl_trait_in_trait_tys`"
-        );
-    }
-
     let trait_sig = ocx.normalize(&misc_cause, param_env, unnormalized_trait_sig);
     trait_sig.error_reported()?;
     let trait_return_ty = trait_sig.output();
@@ -647,6 +639,13 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
         }
     }
 
+    if !unnormalized_trait_sig.output().references_error() {
+        debug_assert!(
+            !collector.types.is_empty(),
+            "expect >0 RPITITs in call to `collect_return_position_impl_trait_in_trait_tys`"
+        );
+    }
+
     // FIXME: This has the same issue as #108544, but since this isn't breaking
     // existing code, I'm not particularly inclined to do the same hack as above
     // where we process wf obligations manually. This can be fixed in a forward-