Auto merge of rust-lang#137608 - fmease:rollup-h4siso6, r=fmease

Rollup of 8 pull requests

Successful merges:

 - rust-lang#137370 (adjust_abi: make fallback logic for ABIs a bit easier to read)
 - rust-lang#137444 (Improve behavior of `IF_LET_RESCOPE` around temporaries and place expressions)
 - rust-lang#137464 (Fix invalid suggestion from type error for derive macro)
 - rust-lang#137539 ( Add rustdoc-gui regression test for rust-lang#137082 )
 - rust-lang#137576 (Don't doc-comment BTreeMap<K, SetValZST, A>)
 - rust-lang#137595 (remove `simd_fpow` and `simd_fpowi`)
 - rust-lang#137600 (type_ir: remove redundant part of comment)
 - rust-lang#137602 (feature: fix typo in attribute description)

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

Author: bors

compiler/rustc_codegen_cranelift/src/intrinsics/simd.rs

@@ -460,64 +460,6 @@ pub(super) fn codegen_simd_intrinsic_call<'tcx>(
             });
         }
 
-        sym::simd_fpow => {
-            intrinsic_args!(fx, args => (a, b); intrinsic);
-
-            if !a.layout().ty.is_simd() {
-                report_simd_type_validation_error(fx, intrinsic, span, a.layout().ty);
-                return;
-            }
-
-            simd_pair_for_each_lane(fx, a, b, ret, &|fx, lane_ty, _ret_lane_ty, a_lane, b_lane| {
-                match lane_ty.kind() {
-                    ty::Float(FloatTy::F32) => fx.lib_call(
-                        "powf",
-                        vec![AbiParam::new(types::F32), AbiParam::new(types::F32)],
-                        vec![AbiParam::new(types::F32)],
-                        &[a_lane, b_lane],
-                    )[0],
-                    ty::Float(FloatTy::F64) => fx.lib_call(
-                        "pow",
-                        vec![AbiParam::new(types::F64), AbiParam::new(types::F64)],
-                        vec![AbiParam::new(types::F64)],
-                        &[a_lane, b_lane],
-                    )[0],
-                    _ => unreachable!("{:?}", lane_ty),
-                }
-            });
-        }
-
-        sym::simd_fpowi => {
-            intrinsic_args!(fx, args => (a, exp); intrinsic);
-            let exp = exp.load_scalar(fx);
-
-            if !a.layout().ty.is_simd() {
-                report_simd_type_validation_error(fx, intrinsic, span, a.layout().ty);
-                return;
-            }
-
-            simd_for_each_lane(
-                fx,
-                a,
-                ret,
-                &|fx, lane_ty, _ret_lane_ty, lane| match lane_ty.kind() {
-                    ty::Float(FloatTy::F32) => fx.lib_call(
-                        "__powisf2", // compiler-builtins
-                        vec![AbiParam::new(types::F32), AbiParam::new(types::I32)],
-                        vec![AbiParam::new(types::F32)],
-                        &[lane, exp],
-                    )[0],
-                    ty::Float(FloatTy::F64) => fx.lib_call(
-                        "__powidf2", // compiler-builtins
-                        vec![AbiParam::new(types::F64), AbiParam::new(types::I32)],
-                        vec![AbiParam::new(types::F64)],
-                        &[lane, exp],
-                    )[0],
-                    _ => unreachable!("{:?}", lane_ty),
-                },
-            );
-        }
-
         sym::simd_fsin
         | sym::simd_fcos
         | sym::simd_fexp

compiler/rustc_codegen_gcc/src/intrinsic/simd.rs

@@ -772,8 +772,6 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             sym::simd_floor => "floor",
             sym::simd_fma => "fma",
             sym::simd_relaxed_fma => "fma", // FIXME: this should relax to non-fused multiply-add when necessary
-            sym::simd_fpowi => "__builtin_powi",
-            sym::simd_fpow => "pow",
             sym::simd_fsin => "sin",
             sym::simd_fsqrt => "sqrt",
             sym::simd_round => "round",
@@ -788,24 +786,16 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
         let mut vector_elements = vec![];
         for i in 0..in_len {
             let index = bx.context.new_rvalue_from_long(bx.ulong_type, i as i64);
-            // we have to treat fpowi specially, since fpowi's second argument is always an i32
             let mut arguments = vec![];
-            if name == sym::simd_fpowi {
-                arguments = vec![
-                    bx.extract_element(args[0].immediate(), index).to_rvalue(),
-                    args[1].immediate(),
-                ];
-            } else {
-                for arg in args {
-                    let mut element = bx.extract_element(arg.immediate(), index).to_rvalue();
-                    // FIXME: it would probably be better to not have casts here and use the proper
-                    // instructions.
-                    if let Some(typ) = cast_type {
-                        element = bx.context.new_cast(None, element, typ);
-                    }
-                    arguments.push(element);
+            for arg in args {
+                let mut element = bx.extract_element(arg.immediate(), index).to_rvalue();
+                // FIXME: it would probably be better to not have casts here and use the proper
+                // instructions.
+                if let Some(typ) = cast_type {
+                    element = bx.context.new_cast(None, element, typ);
                 }
-            };
+                arguments.push(element);
+            }
             let mut result = bx.context.new_call(None, function, &arguments);
             if cast_type.is_some() {
                 result = bx.context.new_cast(None, result, elem_ty);
@@ -829,8 +819,6 @@ pub fn generic_simd_intrinsic<'a, 'gcc, 'tcx>(
             | sym::simd_floor
             | sym::simd_fma
             | sym::simd_relaxed_fma
-            | sym::simd_fpow
-            | sym::simd_fpowi
             | sym::simd_fsin
             | sym::simd_fsqrt
             | sym::simd_round

compiler/rustc_codegen_llvm/src/intrinsic.rs

@@ -1581,8 +1581,6 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
             sym::simd_floor => ("floor", bx.type_func(&[vec_ty], vec_ty)),
             sym::simd_fma => ("fma", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)),
             sym::simd_relaxed_fma => ("fmuladd", bx.type_func(&[vec_ty, vec_ty, vec_ty], vec_ty)),
-            sym::simd_fpowi => ("powi", bx.type_func(&[vec_ty, bx.type_i32()], vec_ty)),
-            sym::simd_fpow => ("pow", bx.type_func(&[vec_ty, vec_ty], vec_ty)),
             sym::simd_fsin => ("sin", bx.type_func(&[vec_ty], vec_ty)),
             sym::simd_fsqrt => ("sqrt", bx.type_func(&[vec_ty], vec_ty)),
             sym::simd_round => ("round", bx.type_func(&[vec_ty], vec_ty)),
@@ -1615,8 +1613,6 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
             | sym::simd_flog
             | sym::simd_floor
             | sym::simd_fma
-            | sym::simd_fpow
-            | sym::simd_fpowi
             | sym::simd_fsin
             | sym::simd_fsqrt
             | sym::simd_relaxed_fma

compiler/rustc_feature/src/builtin_attrs.rs

@@ -1011,7 +1011,7 @@ pub static BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     ),
     rustc_attr!(
         rustc_force_inline, Normal, template!(Word, NameValueStr: "reason"), WarnFollowing, EncodeCrossCrate::Yes,
-        "#![rustc_force_inline] forces a free function to be inlined"
+        "#[rustc_force_inline] forces a free function to be inlined"
     ),
 
     // ==========================================================================

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -645,7 +645,6 @@ pub fn check_intrinsic_type(
             | sym::simd_xor
             | sym::simd_fmin
             | sym::simd_fmax
-            | sym::simd_fpow
             | sym::simd_saturating_add
             | sym::simd_saturating_sub => (1, 0, vec![param(0), param(0)], param(0)),
             sym::simd_arith_offset => (2, 0, vec![param(0), param(1)], param(0)),
@@ -668,7 +667,6 @@ pub fn check_intrinsic_type(
             | sym::simd_floor
             | sym::simd_round
             | sym::simd_trunc => (1, 0, vec![param(0)], param(0)),
-            sym::simd_fpowi => (1, 0, vec![param(0), tcx.types.i32], param(0)),
             sym::simd_fma | sym::simd_relaxed_fma => {
                 (1, 0, vec![param(0), param(0), param(0)], param(0))
             }

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -23,7 +23,7 @@ use rustc_middle::ty::{
 };
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_span::source_map::Spanned;
-use rustc_span::{Ident, Span, Symbol, sym};
+use rustc_span::{ExpnKind, Ident, MacroKind, Span, Symbol, sym};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::error_reporting::traits::DefIdOrName;
 use rustc_trait_selection::infer::InferCtxtExt;
@@ -1365,6 +1365,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.param_env,
                 ty::TraitRef::new(self.tcx, into_def_id, [expr_ty, expected_ty]),
             ))
+            && !expr
+                .span
+                .macro_backtrace()
+                .any(|x| matches!(x.kind, ExpnKind::Macro(MacroKind::Attr | MacroKind::Derive, ..)))
         {
             let span = expr.span.find_oldest_ancestor_in_same_ctxt();
 
@@ -1380,10 +1384,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 sugg.insert(0, (expr.span.shrink_to_lo(), format!("{}: ", name)));
             }
             diag.multipart_suggestion(
-                format!("call `Into::into` on this expression to convert `{expr_ty}` into `{expected_ty}`"),
-                sugg,
-                Applicability::MaybeIncorrect
-            );
+                    format!("call `Into::into` on this expression to convert `{expr_ty}` into `{expected_ty}`"),
+                    sugg,
+                    Applicability::MaybeIncorrect
+                );
             return true;
         }
 

compiler/rustc_lint/src/if_let_rescope.rs

@@ -1,14 +1,15 @@
 use std::iter::repeat;
 use std::ops::ControlFlow;
 
-use hir::intravisit::Visitor;
+use hir::intravisit::{self, Visitor};
 use rustc_ast::Recovered;
 use rustc_errors::{
     Applicability, Diag, EmissionGuarantee, SubdiagMessageOp, Subdiagnostic, SuggestionStyle,
 };
 use rustc_hir::{self as hir, HirIdSet};
 use rustc_macros::LintDiagnostic;
 use rustc_middle::ty::TyCtxt;
+use rustc_middle::ty::adjustment::Adjust;
 use rustc_session::lint::{FutureIncompatibilityReason, LintId};
 use rustc_session::{declare_lint, impl_lint_pass};
 use rustc_span::Span;
@@ -160,7 +161,7 @@ impl IfLetRescope {
                 let lifetime_end = source_map.end_point(conseq.span);
 
                 if let ControlFlow::Break(significant_dropper) =
-                    (FindSignificantDropper { cx }).visit_expr(init)
+                    (FindSignificantDropper { cx }).check_if_let_scrutinee(init)
                 {
                     first_if_to_lint = first_if_to_lint.or_else(|| Some((span, expr.hir_id)));
                     significant_droppers.push(significant_dropper);
@@ -363,96 +364,97 @@ enum SingleArmMatchBegin {
     WithoutOpenBracket(Span),
 }
 
-struct FindSignificantDropper<'tcx, 'a> {
+struct FindSignificantDropper<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
 }
 
-impl<'tcx, 'a> Visitor<'tcx> for FindSignificantDropper<'tcx, 'a> {
-    type Result = ControlFlow<Span>;
+impl<'tcx> FindSignificantDropper<'_, 'tcx> {
+    /// Check the scrutinee of an `if let` to see if it promotes any temporary values
+    /// that would change drop order in edition 2024. Specifically, it checks the value
+    /// of the scrutinee itself, and also recurses into the expression to find any ref
+    /// exprs (or autoref) which would promote temporaries that would be scoped to the
+    /// end of this `if`.
+    fn check_if_let_scrutinee(&mut self, init: &'tcx hir::Expr<'tcx>) -> ControlFlow<Span> {
+        self.check_promoted_temp_with_drop(init)?;
+        self.visit_expr(init)
+    }
 
-    fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Self::Result {
-        if self
+    /// Check that an expression is not a promoted temporary with a significant
+    /// drop impl.
+    ///
+    /// An expression is a promoted temporary if it has an addr taken (i.e. `&expr` or autoref)
+    /// or is the scrutinee of the `if let`, *and* the expression is not a place
+    /// expr, and it has a significant drop.
+    fn check_promoted_temp_with_drop(&self, expr: &'tcx hir::Expr<'tcx>) -> ControlFlow<Span> {
+        if !expr.is_place_expr(|base| {
+            self.cx
+                .typeck_results()
+                .adjustments()
+                .get(base.hir_id)
+                .is_some_and(|x| x.iter().any(|adj| matches!(adj.kind, Adjust::Deref(_))))
+        }) && self
             .cx
             .typeck_results()
             .expr_ty(expr)
             .has_significant_drop(self.cx.tcx, self.cx.typing_env())
         {
-            return ControlFlow::Break(expr.span);
+            ControlFlow::Break(expr.span)
+        } else {
+            ControlFlow::Continue(())
         }
-        match expr.kind {
-            hir::ExprKind::ConstBlock(_)
-            | hir::ExprKind::Lit(_)
-            | hir::ExprKind::Path(_)
-            | hir::ExprKind::Assign(_, _, _)
-            | hir::ExprKind::AssignOp(_, _, _)
-            | hir::ExprKind::Break(_, _)
-            | hir::ExprKind::Continue(_)
-            | hir::ExprKind::Ret(_)
-            | hir::ExprKind::Become(_)
-            | hir::ExprKind::InlineAsm(_)
-            | hir::ExprKind::OffsetOf(_, _)
-            | hir::ExprKind::Repeat(_, _)
-            | hir::ExprKind::Err(_)
-            | hir::ExprKind::Struct(_, _, _)
-            | hir::ExprKind::Closure(_)
-            | hir::ExprKind::Block(_, _)
-            | hir::ExprKind::DropTemps(_)
-            | hir::ExprKind::Loop(_, _, _, _) => ControlFlow::Continue(()),
+    }
+}
 
-            hir::ExprKind::Tup(exprs) | hir::ExprKind::Array(exprs) => {
-                for expr in exprs {
-                    self.visit_expr(expr)?;
-                }
-                ControlFlow::Continue(())
-            }
-            hir::ExprKind::Call(callee, args) => {
-                self.visit_expr(callee)?;
-                for expr in args {
-                    self.visit_expr(expr)?;
-                }
-                ControlFlow::Continue(())
-            }
-            hir::ExprKind::MethodCall(_, receiver, args, _) => {
-                self.visit_expr(receiver)?;
-                for expr in args {
-                    self.visit_expr(expr)?;
+impl<'tcx> Visitor<'tcx> for FindSignificantDropper<'_, 'tcx> {
+    type Result = ControlFlow<Span>;
+
+    fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) -> Self::Result {
+        // Blocks introduce temporary terminating scope for all of its
+        // statements, so just visit the tail expr, skipping over any
+        // statements. This prevents false positives like `{ let x = &Drop; }`.
+        if let Some(expr) = b.expr { self.visit_expr(expr) } else { ControlFlow::Continue(()) }
+    }
+
+    fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Self::Result {
+        // Check for promoted temporaries from autoref, e.g.
+        // `if let None = TypeWithDrop.as_ref() {} else {}`
+        // where `fn as_ref(&self) -> Option<...>`.
+        for adj in self.cx.typeck_results().expr_adjustments(expr) {
+            match adj.kind {
+                // Skip when we hit the first deref expr.
+                Adjust::Deref(_) => break,
+                Adjust::Borrow(_) => {
+                    self.check_promoted_temp_with_drop(expr)?;
                 }
-                ControlFlow::Continue(())
-            }
-            hir::ExprKind::Index(left, right, _) | hir::ExprKind::Binary(_, left, right) => {
-                self.visit_expr(left)?;
-                self.visit_expr(right)
+                _ => {}
             }
-            hir::ExprKind::Unary(_, expr)
-            | hir::ExprKind::Cast(expr, _)
-            | hir::ExprKind::Type(expr, _)
-            | hir::ExprKind::UnsafeBinderCast(_, expr, _)
-            | hir::ExprKind::Yield(expr, _)
-            | hir::ExprKind::AddrOf(_, _, expr)
-            | hir::ExprKind::Match(expr, _, _)
-            | hir::ExprKind::Field(expr, _)
-            | hir::ExprKind::Let(&hir::LetExpr {
-                init: expr,
-                span: _,
-                pat: _,
-                ty: _,
-                recovered: Recovered::No,
-            }) => self.visit_expr(expr),
-            hir::ExprKind::Let(_) => ControlFlow::Continue(()),
+        }
 
-            hir::ExprKind::If(cond, _, _) => {
-                if let hir::ExprKind::Let(hir::LetExpr {
-                    init,
-                    span: _,
-                    pat: _,
-                    ty: _,
-                    recovered: Recovered::No,
-                }) = cond.kind
-                {
-                    self.visit_expr(init)?;
-                }
-                ControlFlow::Continue(())
+        match expr.kind {
+            // Account for cases like `if let None = Some(&Drop) {} else {}`.
+            hir::ExprKind::AddrOf(_, _, expr) => {
+                self.check_promoted_temp_with_drop(expr)?;
+                intravisit::walk_expr(self, expr)
+            }
+            // `(Drop, ()).1` introduces a temporary and then moves out of
+            // part of it, therefore we should check it for temporaries.
+            // FIXME: This may have false positives if we move the part
+            // that actually has drop, but oh well.
+            hir::ExprKind::Index(expr, _, _) | hir::ExprKind::Field(expr, _) => {
+                self.check_promoted_temp_with_drop(expr)?;
+                intravisit::walk_expr(self, expr)
             }
+            // If always introduces a temporary terminating scope for its cond and arms,
+            // so don't visit them.
+            hir::ExprKind::If(..) => ControlFlow::Continue(()),
+            // Match introduces temporary terminating scopes for arms, so don't visit
+            // them, and only visit the scrutinee to account for cases like:
+            // `if let None = match &Drop { _ => Some(1) } {} else {}`.
+            hir::ExprKind::Match(scrut, _, _) => self.visit_expr(scrut),
+            // Self explanatory.
+            hir::ExprKind::DropTemps(_) => ControlFlow::Continue(()),
+            // Otherwise, walk into the expr's parts.
+            _ => intravisit::walk_expr(self, expr),
         }
     }
 }