Auto merge of #128186 - matthiaskrgr:rollup-01b7t98, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #121364 (Implement lint against ambiguous negative literals)
 - #127300 (Fix connect timeout for non-linux targets, read readiness of socket connection, Read readiness to detect errors. `Fixes #127018`)
 - #128138 (`#[naked]`: use an allowlist for allowed options on `asm!` in naked functions)
 - #128158 (std: unsafe-wrap personality::gcc)
 - #128171 (Make sure that args are compatible in `resolve_associated_item`)
 - #128172 (Don't ICE if HIR and middle types disagree in borrowck error reporting)
 - #128173 (Remove crashes for misuses of intrinsics)

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

compiler/rustc_ast/src/ast.rs

@@ -2264,6 +2264,42 @@ bitflags::bitflags! {
     }
 }
 
+impl InlineAsmOptions {
+    pub fn human_readable_names(&self) -> Vec<&'static str> {
+        let mut options = vec![];
+
+        if self.contains(InlineAsmOptions::PURE) {
+            options.push("pure");
+        }
+        if self.contains(InlineAsmOptions::NOMEM) {
+            options.push("nomem");
+        }
+        if self.contains(InlineAsmOptions::READONLY) {
+            options.push("readonly");
+        }
+        if self.contains(InlineAsmOptions::PRESERVES_FLAGS) {
+            options.push("preserves_flags");
+        }
+        if self.contains(InlineAsmOptions::NORETURN) {
+            options.push("noreturn");
+        }
+        if self.contains(InlineAsmOptions::NOSTACK) {
+            options.push("nostack");
+        }
+        if self.contains(InlineAsmOptions::ATT_SYNTAX) {
+            options.push("att_syntax");
+        }
+        if self.contains(InlineAsmOptions::RAW) {
+            options.push("raw");
+        }
+        if self.contains(InlineAsmOptions::MAY_UNWIND) {
+            options.push("may_unwind");
+        }
+
+        options
+    }
+}
+
 impl std::fmt::Debug for InlineAsmOptions {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         bitflags::parser::to_writer(self, f)

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1505,35 +1505,7 @@ impl<'a> State<'a> {
             AsmArg::Options(opts) => {
                 s.word("options");
                 s.popen();
-                let mut options = vec![];
-                if opts.contains(InlineAsmOptions::PURE) {
-                    options.push("pure");
-                }
-                if opts.contains(InlineAsmOptions::NOMEM) {
-                    options.push("nomem");
-                }
-                if opts.contains(InlineAsmOptions::READONLY) {
-                    options.push("readonly");
-                }
-                if opts.contains(InlineAsmOptions::PRESERVES_FLAGS) {
-                    options.push("preserves_flags");
-                }
-                if opts.contains(InlineAsmOptions::NORETURN) {
-                    options.push("noreturn");
-                }
-                if opts.contains(InlineAsmOptions::NOSTACK) {
-                    options.push("nostack");
-                }
-                if opts.contains(InlineAsmOptions::ATT_SYNTAX) {
-                    options.push("att_syntax");
-                }
-                if opts.contains(InlineAsmOptions::RAW) {
-                    options.push("raw");
-                }
-                if opts.contains(InlineAsmOptions::MAY_UNWIND) {
-                    options.push("may_unwind");
-                }
-                s.commasep(Inconsistent, &options, |s, &opt| {
+                s.commasep(Inconsistent, &opts.human_readable_names(), |s, &opt| {
                     s.word(opt);
                 });
                 s.pclose();

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -4304,17 +4304,35 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
                 // search for relevant arguments.
                 let mut arguments = Vec::new();
                 for (index, argument) in sig.inputs().skip_binder().iter().enumerate() {
-                    if let ty::Ref(argument_region, _, _) = argument.kind() {
-                        if argument_region == return_region {
-                            // Need to use the `rustc_middle::ty` types to compare against the
-                            // `return_region`. Then use the `rustc_hir` type to get only
-                            // the lifetime span.
-                            if let hir::TyKind::Ref(lifetime, _) = &fn_decl.inputs[index].kind {
+                    if let ty::Ref(argument_region, _, _) = argument.kind()
+                        && argument_region == return_region
+                    {
+                        // Need to use the `rustc_middle::ty` types to compare against the
+                        // `return_region`. Then use the `rustc_hir` type to get only
+                        // the lifetime span.
+                        match &fn_decl.inputs[index].kind {
+                            hir::TyKind::Ref(lifetime, _) => {
                                 // With access to the lifetime, we can get
                                 // the span of it.
                                 arguments.push((*argument, lifetime.ident.span));
-                            } else {
-                                bug!("ty type is a ref but hir type is not");
+                            }
+                            // Resolve `self` whose self type is `&T`.
+                            hir::TyKind::Path(hir::QPath::Resolved(None, path)) => {
+                                if let Res::SelfTyAlias { alias_to, .. } = path.res
+                                    && let Some(alias_to) = alias_to.as_local()
+                                    && let hir::Impl { self_ty, .. } = self
+                                        .infcx
+                                        .tcx
+                                        .hir_node_by_def_id(alias_to)
+                                        .expect_item()
+                                        .expect_impl()
+                                    && let hir::TyKind::Ref(lifetime, _) = self_ty.kind
+                                {
+                                    arguments.push((*argument, lifetime.ident.span));
+                                }
+                            }
+                            _ => {
+                                // Don't ICE though. It might be a type alias.
                             }
                         }
                     }

compiler/rustc_hir_pretty/src/lib.rs

@@ -1298,35 +1298,7 @@ impl<'a> State<'a> {
             AsmArg::Options(opts) => {
                 s.word("options");
                 s.popen();
-                let mut options = vec![];
-                if opts.contains(ast::InlineAsmOptions::PURE) {
-                    options.push("pure");
-                }
-                if opts.contains(ast::InlineAsmOptions::NOMEM) {
-                    options.push("nomem");
-                }
-                if opts.contains(ast::InlineAsmOptions::READONLY) {
-                    options.push("readonly");
-                }
-                if opts.contains(ast::InlineAsmOptions::PRESERVES_FLAGS) {
-                    options.push("preserves_flags");
-                }
-                if opts.contains(ast::InlineAsmOptions::NORETURN) {
-                    options.push("noreturn");
-                }
-                if opts.contains(ast::InlineAsmOptions::NOSTACK) {
-                    options.push("nostack");
-                }
-                if opts.contains(ast::InlineAsmOptions::ATT_SYNTAX) {
-                    options.push("att_syntax");
-                }
-                if opts.contains(ast::InlineAsmOptions::RAW) {
-                    options.push("raw");
-                }
-                if opts.contains(ast::InlineAsmOptions::MAY_UNWIND) {
-                    options.push("may_unwind");
-                }
-                s.commasep(Inconsistent, &options, |s, &opt| {
+                s.commasep(Inconsistent, &opts.human_readable_names(), |s, &opt| {
                     s.word(opt);
                 });
                 s.pclose();

compiler/rustc_lint/messages.ftl

@@ -5,6 +5,11 @@ lint_ambiguous_glob_reexport = ambiguous glob re-exports
     .label_first_reexport = the name `{$name}` in the {$namespace} namespace is first re-exported here
     .label_duplicate_reexport = but the name `{$name}` in the {$namespace} namespace is also re-exported here
 
+lint_ambiguous_negative_literals = `-` has lower precedence than method calls, which might be unexpected
+    .example = e.g. `-4.abs()` equals `-4`; while `(-4).abs()` equals `4`
+    .negative_literal = add parentheses around the `-` and the literal to call the method on a negative literal
+    .current_behavior = add parentheses around the literal and the method call to keep the current behavior
+
 lint_ambiguous_wide_pointer_comparisons = ambiguous wide pointer comparison, the comparison includes metadata which may not be expected
     .addr_metadata_suggestion = use explicit `std::ptr::eq` method to compare metadata and addresses
     .addr_suggestion = use `std::ptr::addr_eq` or untyped pointers to only compare their addresses

compiler/rustc_lint/src/lib.rs

@@ -73,6 +73,7 @@ mod noop_method_call;
 mod opaque_hidden_inferred_bound;
 mod pass_by_value;
 mod passes;
+mod precedence;
 mod ptr_nulls;
 mod redundant_semicolon;
 mod reference_casting;
@@ -111,6 +112,7 @@ use nonstandard_style::*;
 use noop_method_call::*;
 use opaque_hidden_inferred_bound::*;
 use pass_by_value::*;
+use precedence::*;
 use ptr_nulls::*;
 use redundant_semicolon::*;
 use reference_casting::*;
@@ -174,6 +176,7 @@ early_lint_methods!(
             RedundantSemicolons: RedundantSemicolons,
             UnusedDocComment: UnusedDocComment,
             Expr2024: Expr2024,
+            Precedence: Precedence,
         ]
     ]
 );

compiler/rustc_lint/src/lints.rs

@@ -1499,6 +1499,35 @@ pub struct NonLocalDefinitionsCargoUpdateNote {
     pub crate_name: Symbol,
 }
 
+// precedence.rs
+#[derive(LintDiagnostic)]
+#[diag(lint_ambiguous_negative_literals)]
+#[note(lint_example)]
+pub struct AmbiguousNegativeLiteralsDiag {
+    #[subdiagnostic]
+    pub negative_literal: AmbiguousNegativeLiteralsNegativeLiteralSuggestion,
+    #[subdiagnostic]
+    pub current_behavior: AmbiguousNegativeLiteralsCurrentBehaviorSuggestion,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(lint_negative_literal, applicability = "maybe-incorrect")]
+pub struct AmbiguousNegativeLiteralsNegativeLiteralSuggestion {
+    #[suggestion_part(code = "(")]
+    pub start_span: Span,
+    #[suggestion_part(code = ")")]
+    pub end_span: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[multipart_suggestion(lint_current_behavior, applicability = "maybe-incorrect")]
+pub struct AmbiguousNegativeLiteralsCurrentBehaviorSuggestion {
+    #[suggestion_part(code = "(")]
+    pub start_span: Span,
+    #[suggestion_part(code = ")")]
+    pub end_span: Span,
+}
+
 // pass_by_value.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_pass_by_value)]

compiler/rustc_lint/src/precedence.rs

@@ -0,0 +1,70 @@
+use rustc_ast::token::LitKind;
+use rustc_ast::{Expr, ExprKind, MethodCall, UnOp};
+use rustc_session::{declare_lint, declare_lint_pass};
+
+use crate::lints::{
+    AmbiguousNegativeLiteralsCurrentBehaviorSuggestion, AmbiguousNegativeLiteralsDiag,
+    AmbiguousNegativeLiteralsNegativeLiteralSuggestion,
+};
+use crate::{EarlyContext, EarlyLintPass, LintContext};
+
+declare_lint! {
+    /// The `ambiguous_negative_literals` lint checks for cases that are
+    /// confusing between a negative literal and a negation that's not part
+    /// of the literal.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #![allow(unused)]
+    /// -1i32.abs(); // equals -1, while `(-1i32).abs()` equals 1
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Method calls take precedence over unary precedence. Setting the
+    /// precedence explicitly makes the code clearer and avoid potential bugs.
+    pub AMBIGUOUS_NEGATIVE_LITERALS,
+    Deny,
+    "ambiguous negative literals operations",
+    report_in_external_macro
+}
+
+declare_lint_pass!(Precedence => [AMBIGUOUS_NEGATIVE_LITERALS]);
+
+impl EarlyLintPass for Precedence {
+    fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+        let ExprKind::Unary(UnOp::Neg, operand) = &expr.kind else {
+            return;
+        };
+
+        let mut arg = operand;
+        let mut at_least_one = false;
+        while let ExprKind::MethodCall(box MethodCall { receiver, .. }) = &arg.kind {
+            at_least_one = true;
+            arg = receiver;
+        }
+
+        if at_least_one
+            && let ExprKind::Lit(lit) = &arg.kind
+            && let LitKind::Integer | LitKind::Float = &lit.kind
+        {
+            cx.emit_span_lint(
+                AMBIGUOUS_NEGATIVE_LITERALS,
+                expr.span,
+                AmbiguousNegativeLiteralsDiag {
+                    negative_literal: AmbiguousNegativeLiteralsNegativeLiteralSuggestion {
+                        start_span: expr.span.shrink_to_lo(),
+                        end_span: arg.span.shrink_to_hi(),
+                    },
+                    current_behavior: AmbiguousNegativeLiteralsCurrentBehaviorSuggestion {
+                        start_span: operand.span.shrink_to_lo(),
+                        end_span: operand.span.shrink_to_hi(),
+                    },
+                },
+            );
+        }
+    }
+}

compiler/rustc_passes/src/naked_functions.rs

@@ -244,22 +244,19 @@ impl<'tcx> CheckInlineAssembly<'tcx> {
             self.tcx.dcx().emit_err(NakedFunctionsOperands { unsupported_operands });
         }
 
-        let unsupported_options: Vec<&'static str> = [
-            (InlineAsmOptions::MAY_UNWIND, "`may_unwind`"),
-            (InlineAsmOptions::NOMEM, "`nomem`"),
-            (InlineAsmOptions::NOSTACK, "`nostack`"),
-            (InlineAsmOptions::PRESERVES_FLAGS, "`preserves_flags`"),
-            (InlineAsmOptions::PURE, "`pure`"),
-            (InlineAsmOptions::READONLY, "`readonly`"),
-        ]
-        .iter()
-        .filter_map(|&(option, name)| if asm.options.contains(option) { Some(name) } else { None })
-        .collect();
+        let supported_options =
+            InlineAsmOptions::RAW | InlineAsmOptions::NORETURN | InlineAsmOptions::ATT_SYNTAX;
+        let unsupported_options = asm.options.difference(supported_options);
 
         if !unsupported_options.is_empty() {
             self.tcx.dcx().emit_err(NakedFunctionsAsmOptions {
                 span,
-                unsupported_options: unsupported_options.join(", "),
+                unsupported_options: unsupported_options
+                    .human_readable_names()
+                    .into_iter()
+                    .map(|name| format!("`{name}`"))
+                    .collect::<Vec<_>>()
+                    .join(", "),
             });
         }
 

compiler/rustc_ty_utils/src/instance.rs

@@ -191,11 +191,22 @@ fn resolve_associated_item<'tcx>(
 
             // Any final impl is required to define all associated items.
             if !leaf_def.item.defaultness(tcx).has_value() {
-                let guard = tcx.dcx().span_delayed_bug(
+                let guar = tcx.dcx().span_delayed_bug(
                     tcx.def_span(leaf_def.item.def_id),
                     "missing value for assoc item in impl",
                 );
-                return Err(guard);
+                return Err(guar);
+            }
+
+            // Make sure that we're projecting to an item that has compatible args.
+            // This may happen if we are resolving an instance before codegen, such
+            // as during inlining. This check is also done in projection.
+            if !tcx.check_args_compatible(leaf_def.item.def_id, args) {
+                let guar = tcx.dcx().span_delayed_bug(
+                    tcx.def_span(leaf_def.item.def_id),
+                    "missing value for assoc item in impl",
+                );
+                return Err(guar);
             }
 
             let args = tcx.erase_regions(args);

library/std/src/sys/pal/unix/net.rs

@@ -214,16 +214,25 @@ impl Socket {
                 }
                 0 => {}
                 _ => {
-                    // linux returns POLLOUT|POLLERR|POLLHUP for refused connections (!), so look
-                    // for POLLHUP rather than read readiness
-                    if pollfd.revents & libc::POLLHUP != 0 {
-                        let e = self.take_error()?.unwrap_or_else(|| {
-                            io::const_io_error!(
-                                io::ErrorKind::Uncategorized,
-                                "no error set after POLLHUP",
-                            )
-                        });
-                        return Err(e);
+                    if cfg!(target_os = "vxworks") {
+                        // VxWorks poll does not return  POLLHUP or POLLERR in revents. Check if the
+                        // connnection actually succeeded and return ok only when the socket is
+                        // ready and no errors were found.
+                        if let Some(e) = self.take_error()? {
+                            return Err(e);
+                        }
+                    } else {
+                        // linux returns POLLOUT|POLLERR|POLLHUP for refused connections (!), so look
+                        // for POLLHUP or POLLERR rather than read readiness
+                        if pollfd.revents & (libc::POLLHUP | libc::POLLERR) != 0 {
+                            let e = self.take_error()?.unwrap_or_else(|| {
+                                io::const_io_error!(
+                                    io::ErrorKind::Uncategorized,
+                                    "no error set after POLLHUP",
+                                )
+                            });
+                            return Err(e);
+                        }
                     }
 
                     return Ok(());