2014 lines
75 KiB
Rust
2014 lines
75 KiB
Rust
//! Lints in the Rust compiler.
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//!
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//! This contains lints which can feasibly be implemented as their own
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//! AST visitor. Also see `rustc::lint::builtin`, which contains the
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//! definitions of lints that are emitted directly inside the main
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//! compiler.
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//!
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//! To add a new lint to rustc, declare it here using `declare_lint!()`.
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//! Then add code to emit the new lint in the appropriate circumstances.
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//! You can do that in an existing `LintPass` if it makes sense, or in a
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//! new `LintPass`, or using `Session::add_lint` elsewhere in the
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//! compiler. Only do the latter if the check can't be written cleanly as a
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//! `LintPass` (also, note that such lints will need to be defined in
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//! `rustc::lint::builtin`, not here).
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//!
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//! If you define a new `EarlyLintPass`, you will also need to add it to the
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//! `add_early_builtin!` or `add_early_builtin_with_new!` invocation in
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//! `lib.rs`. Use the former for unit-like structs and the latter for structs
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//! with a `pub fn new()`.
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//!
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//! If you define a new `LateLintPass`, you will also need to add it to the
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//! `late_lint_methods!` invocation in `lib.rs`.
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use std::fmt::Write;
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use rustc::hir::def::{Res, DefKind};
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use rustc::hir::def_id::DefId;
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use rustc::ty::{self, Ty, TyCtxt, layout::VariantIdx};
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use rustc::{lint, util};
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use rustc::lint::FutureIncompatibleInfo;
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use hir::Node;
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use util::nodemap::HirIdSet;
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use lint::{LateContext, LintContext, LintArray};
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use lint::{LintPass, LateLintPass, EarlyLintPass, EarlyContext};
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use rustc::util::nodemap::FxHashSet;
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use rustc_feature::{AttributeGate, AttributeTemplate, AttributeType, deprecated_attributes};
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use rustc_feature::Stability;
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use syntax::tokenstream::{TokenTree, TokenStream};
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use syntax::ast::{self, Expr};
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use syntax::ptr::P;
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use syntax::attr::{self, HasAttrs};
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use syntax::source_map::Spanned;
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use syntax::edition::Edition;
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use syntax_pos::{BytePos, Span};
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use syntax::symbol::{Symbol, kw, sym};
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use syntax::errors::{Applicability, DiagnosticBuilder};
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use syntax::print::pprust::{self, expr_to_string};
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use syntax::visit::FnKind;
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use rustc::hir::{self, GenericParamKind, PatKind};
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use crate::nonstandard_style::{MethodLateContext, method_context};
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use log::debug;
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// hardwired lints from librustc
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pub use lint::builtin::*;
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declare_lint! {
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WHILE_TRUE,
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Warn,
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"suggest using `loop { }` instead of `while true { }`"
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}
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declare_lint_pass!(WhileTrue => [WHILE_TRUE]);
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/// Traverse through any amount of parenthesis and return the first non-parens expression.
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fn pierce_parens(mut expr: &ast::Expr) -> &ast::Expr {
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while let ast::ExprKind::Paren(sub) = &expr.kind {
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expr = sub;
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}
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expr
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}
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impl EarlyLintPass for WhileTrue {
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fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
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if let ast::ExprKind::While(cond, ..) = &e.kind {
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if let ast::ExprKind::Lit(ref lit) = pierce_parens(cond).kind {
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if let ast::LitKind::Bool(true) = lit.kind {
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if !lit.span.from_expansion() {
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let msg = "denote infinite loops with `loop { ... }`";
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let condition_span = cx.sess.source_map().def_span(e.span);
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cx.struct_span_lint(WHILE_TRUE, condition_span, msg)
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.span_suggestion_short(
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condition_span,
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"use `loop`",
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"loop".to_owned(),
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Applicability::MachineApplicable
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)
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.emit();
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}
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}
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}
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}
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}
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}
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declare_lint! {
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BOX_POINTERS,
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Allow,
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"use of owned (Box type) heap memory"
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}
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declare_lint_pass!(BoxPointers => [BOX_POINTERS]);
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impl BoxPointers {
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fn check_heap_type(&self, cx: &LateContext<'_, '_>, span: Span, ty: Ty<'_>) {
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for leaf_ty in ty.walk() {
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if leaf_ty.is_box() {
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let m = format!("type uses owned (Box type) pointers: {}", ty);
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cx.span_lint(BOX_POINTERS, span, &m);
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}
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}
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}
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}
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxPointers {
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fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item) {
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match it.kind {
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hir::ItemKind::Fn(..) |
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hir::ItemKind::TyAlias(..) |
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hir::ItemKind::Enum(..) |
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hir::ItemKind::Struct(..) |
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hir::ItemKind::Union(..) => {
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let def_id = cx.tcx.hir().local_def_id(it.hir_id);
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self.check_heap_type(cx, it.span, cx.tcx.type_of(def_id))
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}
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_ => ()
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}
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// If it's a struct, we also have to check the fields' types
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match it.kind {
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hir::ItemKind::Struct(ref struct_def, _) |
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hir::ItemKind::Union(ref struct_def, _) => {
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for struct_field in struct_def.fields() {
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let def_id = cx.tcx.hir().local_def_id(struct_field.hir_id);
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self.check_heap_type(cx, struct_field.span,
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cx.tcx.type_of(def_id));
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}
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}
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_ => (),
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}
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}
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fn check_expr(&mut self, cx: &LateContext<'_, '_>, e: &hir::Expr) {
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let ty = cx.tables.node_type(e.hir_id);
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self.check_heap_type(cx, e.span, ty);
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}
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}
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declare_lint! {
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NON_SHORTHAND_FIELD_PATTERNS,
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Warn,
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"using `Struct { x: x }` instead of `Struct { x }` in a pattern"
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}
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declare_lint_pass!(NonShorthandFieldPatterns => [NON_SHORTHAND_FIELD_PATTERNS]);
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonShorthandFieldPatterns {
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fn check_pat(&mut self, cx: &LateContext<'_, '_>, pat: &hir::Pat) {
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if let PatKind::Struct(ref qpath, ref field_pats, _) = pat.kind {
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let variant = cx.tables.pat_ty(pat).ty_adt_def()
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.expect("struct pattern type is not an ADT")
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.variant_of_res(cx.tables.qpath_res(qpath, pat.hir_id));
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for fieldpat in field_pats {
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if fieldpat.is_shorthand {
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continue;
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}
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if fieldpat.span.from_expansion() {
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// Don't lint if this is a macro expansion: macro authors
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// shouldn't have to worry about this kind of style issue
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// (Issue #49588)
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continue;
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}
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if let PatKind::Binding(_, _, ident, None) = fieldpat.pat.kind {
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if cx.tcx.find_field_index(ident, &variant) ==
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Some(cx.tcx.field_index(fieldpat.hir_id, cx.tables)) {
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let mut err = cx.struct_span_lint(NON_SHORTHAND_FIELD_PATTERNS,
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fieldpat.span,
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&format!("the `{}:` in this pattern is redundant", ident));
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let subspan = cx.tcx.sess.source_map().span_through_char(fieldpat.span,
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':');
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err.span_suggestion_short(
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subspan,
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"remove this",
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ident.to_string(),
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Applicability::MachineApplicable
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);
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err.emit();
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}
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}
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}
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}
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}
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}
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declare_lint! {
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UNSAFE_CODE,
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Allow,
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"usage of `unsafe` code"
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}
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declare_lint_pass!(UnsafeCode => [UNSAFE_CODE]);
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impl UnsafeCode {
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fn report_unsafe(&self, cx: &EarlyContext<'_>, span: Span, desc: &'static str) {
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// This comes from a macro that has `#[allow_internal_unsafe]`.
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if span.allows_unsafe() {
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return;
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}
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cx.span_lint(UNSAFE_CODE, span, desc);
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}
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}
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impl EarlyLintPass for UnsafeCode {
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fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &ast::Attribute) {
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if attr.check_name(sym::allow_internal_unsafe) {
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self.report_unsafe(cx, attr.span, "`allow_internal_unsafe` allows defining \
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macros using unsafe without triggering \
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the `unsafe_code` lint at their call site");
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}
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}
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fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
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if let ast::ExprKind::Block(ref blk, _) = e.kind {
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// Don't warn about generated blocks; that'll just pollute the output.
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if blk.rules == ast::BlockCheckMode::Unsafe(ast::UserProvided) {
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self.report_unsafe(cx, blk.span, "usage of an `unsafe` block");
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}
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}
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}
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fn check_item(&mut self, cx: &EarlyContext<'_>, it: &ast::Item) {
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match it.kind {
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ast::ItemKind::Trait(_, ast::Unsafety::Unsafe, ..) => {
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self.report_unsafe(cx, it.span, "declaration of an `unsafe` trait")
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}
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ast::ItemKind::Impl(ast::Unsafety::Unsafe, ..) => {
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self.report_unsafe(cx, it.span, "implementation of an `unsafe` trait")
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}
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_ => return,
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}
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}
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fn check_fn(&mut self,
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cx: &EarlyContext<'_>,
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fk: FnKind<'_>,
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_: &ast::FnDecl,
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span: Span,
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_: ast::NodeId) {
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match fk {
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FnKind::ItemFn(_, ast::FnHeader { unsafety: ast::Unsafety::Unsafe, .. }, ..) => {
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self.report_unsafe(cx, span, "declaration of an `unsafe` function")
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}
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FnKind::Method(_, sig, ..) => {
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if sig.header.unsafety == ast::Unsafety::Unsafe {
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self.report_unsafe(cx, span, "implementation of an `unsafe` method")
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}
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}
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_ => (),
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}
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}
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fn check_trait_item(&mut self, cx: &EarlyContext<'_>, item: &ast::AssocItem) {
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if let ast::AssocItemKind::Fn(ref sig, None) = item.kind {
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if sig.header.unsafety == ast::Unsafety::Unsafe {
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self.report_unsafe(cx, item.span, "declaration of an `unsafe` method")
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}
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}
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}
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}
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declare_lint! {
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pub MISSING_DOCS,
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Allow,
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"detects missing documentation for public members",
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report_in_external_macro
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}
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pub struct MissingDoc {
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/// Stack of whether `#[doc(hidden)]` is set at each level which has lint attributes.
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doc_hidden_stack: Vec<bool>,
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/// Private traits or trait items that leaked through. Don't check their methods.
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private_traits: FxHashSet<hir::HirId>,
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}
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impl_lint_pass!(MissingDoc => [MISSING_DOCS]);
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fn has_doc(attr: &ast::Attribute) -> bool {
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if !attr.check_name(sym::doc) {
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return false;
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}
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if attr.is_value_str() {
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return true;
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}
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if let Some(list) = attr.meta_item_list() {
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for meta in list {
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if meta.check_name(sym::include) || meta.check_name(sym::hidden) {
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return true;
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}
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}
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}
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false
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}
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impl MissingDoc {
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pub fn new() -> MissingDoc {
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MissingDoc {
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doc_hidden_stack: vec![false],
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private_traits: FxHashSet::default(),
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}
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}
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fn doc_hidden(&self) -> bool {
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*self.doc_hidden_stack.last().expect("empty doc_hidden_stack")
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}
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fn check_missing_docs_attrs(&self,
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cx: &LateContext<'_, '_>,
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id: Option<hir::HirId>,
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attrs: &[ast::Attribute],
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sp: Span,
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desc: &'static str) {
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// If we're building a test harness, then warning about
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// documentation is probably not really relevant right now.
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if cx.sess().opts.test {
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return;
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}
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// `#[doc(hidden)]` disables missing_docs check.
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if self.doc_hidden() {
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return;
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}
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// Only check publicly-visible items, using the result from the privacy pass.
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// It's an option so the crate root can also use this function (it doesn't
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// have a `NodeId`).
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if let Some(id) = id {
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if !cx.access_levels.is_exported(id) {
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return;
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}
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}
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let has_doc = attrs.iter().any(|a| has_doc(a));
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if !has_doc {
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cx.span_lint(MISSING_DOCS,
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cx.tcx.sess.source_map().def_span(sp),
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&format!("missing documentation for {}", desc));
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}
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}
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}
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDoc {
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fn enter_lint_attrs(&mut self, _: &LateContext<'_, '_>, attrs: &[ast::Attribute]) {
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let doc_hidden = self.doc_hidden() ||
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attrs.iter().any(|attr| {
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attr.check_name(sym::doc) &&
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match attr.meta_item_list() {
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None => false,
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Some(l) => attr::list_contains_name(&l, sym::hidden),
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}
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});
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self.doc_hidden_stack.push(doc_hidden);
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}
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fn exit_lint_attrs(&mut self, _: &LateContext<'_, '_>, _attrs: &[ast::Attribute]) {
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self.doc_hidden_stack.pop().expect("empty doc_hidden_stack");
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}
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fn check_crate(&mut self, cx: &LateContext<'_, '_>, krate: &hir::Crate) {
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self.check_missing_docs_attrs(cx, None, &krate.attrs, krate.span, "crate");
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for macro_def in &krate.exported_macros {
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let has_doc = macro_def.attrs.iter().any(|a| has_doc(a));
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if !has_doc {
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cx.span_lint(MISSING_DOCS,
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cx.tcx.sess.source_map().def_span(macro_def.span),
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"missing documentation for macro");
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}
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}
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}
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fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item) {
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let desc = match it.kind {
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hir::ItemKind::Fn(..) => "a function",
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hir::ItemKind::Mod(..) => "a module",
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hir::ItemKind::Enum(..) => "an enum",
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hir::ItemKind::Struct(..) => "a struct",
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hir::ItemKind::Union(..) => "a union",
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hir::ItemKind::Trait(.., ref trait_item_refs) => {
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// Issue #11592: traits are always considered exported, even when private.
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if let hir::VisibilityKind::Inherited = it.vis.node {
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self.private_traits.insert(it.hir_id);
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for trait_item_ref in trait_item_refs {
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self.private_traits.insert(trait_item_ref.id.hir_id);
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}
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return;
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}
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"a trait"
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}
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hir::ItemKind::TyAlias(..) => "a type alias",
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hir::ItemKind::Impl(.., Some(ref trait_ref), _, ref impl_item_refs) => {
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// If the trait is private, add the impl items to `private_traits` so they don't get
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// reported for missing docs.
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let real_trait = trait_ref.path.res.def_id();
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if let Some(hir_id) = cx.tcx.hir().as_local_hir_id(real_trait) {
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match cx.tcx.hir().find(hir_id) {
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Some(Node::Item(item)) => {
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if let hir::VisibilityKind::Inherited = item.vis.node {
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for impl_item_ref in impl_item_refs {
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self.private_traits.insert(impl_item_ref.id.hir_id);
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}
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}
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}
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_ => {}
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}
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}
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return;
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}
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hir::ItemKind::Const(..) => "a constant",
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hir::ItemKind::Static(..) => "a static",
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_ => return,
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};
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self.check_missing_docs_attrs(cx, Some(it.hir_id), &it.attrs, it.span, desc);
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}
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fn check_trait_item(&mut self, cx: &LateContext<'_, '_>, trait_item: &hir::TraitItem) {
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if self.private_traits.contains(&trait_item.hir_id) {
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return;
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}
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let desc = match trait_item.kind {
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hir::TraitItemKind::Const(..) => "an associated constant",
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hir::TraitItemKind::Method(..) => "a trait method",
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hir::TraitItemKind::Type(..) => "an associated type",
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};
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self.check_missing_docs_attrs(cx,
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Some(trait_item.hir_id),
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&trait_item.attrs,
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trait_item.span,
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desc);
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}
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fn check_impl_item(&mut self, cx: &LateContext<'_, '_>, impl_item: &hir::ImplItem) {
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// If the method is an impl for a trait, don't doc.
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if method_context(cx, impl_item.hir_id) == MethodLateContext::TraitImpl {
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return;
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}
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let desc = match impl_item.kind {
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hir::ImplItemKind::Const(..) => "an associated constant",
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hir::ImplItemKind::Method(..) => "a method",
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hir::ImplItemKind::TyAlias(_) => "an associated type",
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hir::ImplItemKind::OpaqueTy(_) => "an associated `impl Trait` type",
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};
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self.check_missing_docs_attrs(cx,
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Some(impl_item.hir_id),
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&impl_item.attrs,
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impl_item.span,
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desc);
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}
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fn check_struct_field(&mut self, cx: &LateContext<'_, '_>, sf: &hir::StructField) {
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if !sf.is_positional() {
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self.check_missing_docs_attrs(cx,
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Some(sf.hir_id),
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&sf.attrs,
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sf.span,
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"a struct field")
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}
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}
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|
|
fn check_variant(&mut self, cx: &LateContext<'_, '_>, v: &hir::Variant) {
|
|
self.check_missing_docs_attrs(cx,
|
|
Some(v.id),
|
|
&v.attrs,
|
|
v.span,
|
|
"a variant");
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub MISSING_COPY_IMPLEMENTATIONS,
|
|
Allow,
|
|
"detects potentially-forgotten implementations of `Copy`"
|
|
}
|
|
|
|
declare_lint_pass!(MissingCopyImplementations => [MISSING_COPY_IMPLEMENTATIONS]);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingCopyImplementations {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::Item) {
|
|
if !cx.access_levels.is_reachable(item.hir_id) {
|
|
return;
|
|
}
|
|
let (def, ty) = match item.kind {
|
|
hir::ItemKind::Struct(_, ref ast_generics) => {
|
|
if !ast_generics.params.is_empty() {
|
|
return;
|
|
}
|
|
let def = cx.tcx.adt_def(cx.tcx.hir().local_def_id(item.hir_id));
|
|
(def, cx.tcx.mk_adt(def, cx.tcx.intern_substs(&[])))
|
|
}
|
|
hir::ItemKind::Union(_, ref ast_generics) => {
|
|
if !ast_generics.params.is_empty() {
|
|
return;
|
|
}
|
|
let def = cx.tcx.adt_def(cx.tcx.hir().local_def_id(item.hir_id));
|
|
(def, cx.tcx.mk_adt(def, cx.tcx.intern_substs(&[])))
|
|
}
|
|
hir::ItemKind::Enum(_, ref ast_generics) => {
|
|
if !ast_generics.params.is_empty() {
|
|
return;
|
|
}
|
|
let def = cx.tcx.adt_def(cx.tcx.hir().local_def_id(item.hir_id));
|
|
(def, cx.tcx.mk_adt(def, cx.tcx.intern_substs(&[])))
|
|
}
|
|
_ => return,
|
|
};
|
|
if def.has_dtor(cx.tcx) {
|
|
return;
|
|
}
|
|
let param_env = ty::ParamEnv::empty();
|
|
if ty.is_copy_modulo_regions(cx.tcx, param_env, item.span) {
|
|
return;
|
|
}
|
|
if param_env.can_type_implement_copy(cx.tcx, ty).is_ok() {
|
|
cx.span_lint(MISSING_COPY_IMPLEMENTATIONS,
|
|
item.span,
|
|
"type could implement `Copy`; consider adding `impl \
|
|
Copy`")
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
MISSING_DEBUG_IMPLEMENTATIONS,
|
|
Allow,
|
|
"detects missing implementations of fmt::Debug"
|
|
}
|
|
|
|
#[derive(Default)]
|
|
pub struct MissingDebugImplementations {
|
|
impling_types: Option<HirIdSet>,
|
|
}
|
|
|
|
impl_lint_pass!(MissingDebugImplementations => [MISSING_DEBUG_IMPLEMENTATIONS]);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MissingDebugImplementations {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::Item) {
|
|
if !cx.access_levels.is_reachable(item.hir_id) {
|
|
return;
|
|
}
|
|
|
|
match item.kind {
|
|
hir::ItemKind::Struct(..) |
|
|
hir::ItemKind::Union(..) |
|
|
hir::ItemKind::Enum(..) => {}
|
|
_ => return,
|
|
}
|
|
|
|
let debug = match cx.tcx.get_diagnostic_item(sym::debug_trait) {
|
|
Some(debug) => debug,
|
|
None => return,
|
|
};
|
|
|
|
if self.impling_types.is_none() {
|
|
let mut impls = HirIdSet::default();
|
|
cx.tcx.for_each_impl(debug, |d| {
|
|
if let Some(ty_def) = cx.tcx.type_of(d).ty_adt_def() {
|
|
if let Some(hir_id) = cx.tcx.hir().as_local_hir_id(ty_def.did) {
|
|
impls.insert(hir_id);
|
|
}
|
|
}
|
|
});
|
|
|
|
self.impling_types = Some(impls);
|
|
debug!("{:?}", self.impling_types);
|
|
}
|
|
|
|
if !self.impling_types.as_ref().unwrap().contains(&item.hir_id) {
|
|
cx.span_lint(MISSING_DEBUG_IMPLEMENTATIONS,
|
|
item.span,
|
|
"type does not implement `fmt::Debug`; consider adding `#[derive(Debug)]` \
|
|
or a manual implementation")
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub ANONYMOUS_PARAMETERS,
|
|
Allow,
|
|
"detects anonymous parameters",
|
|
@future_incompatible = FutureIncompatibleInfo {
|
|
reference: "issue #41686 <https://github.com/rust-lang/rust/issues/41686>",
|
|
edition: Some(Edition::Edition2018),
|
|
};
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Checks for use of anonymous parameters (RFC 1685).
|
|
AnonymousParameters => [ANONYMOUS_PARAMETERS]
|
|
);
|
|
|
|
impl EarlyLintPass for AnonymousParameters {
|
|
fn check_trait_item(&mut self, cx: &EarlyContext<'_>, it: &ast::AssocItem) {
|
|
match it.kind {
|
|
ast::AssocItemKind::Fn(ref sig, _) => {
|
|
for arg in sig.decl.inputs.iter() {
|
|
match arg.pat.kind {
|
|
ast::PatKind::Ident(_, ident, None) => {
|
|
if ident.name == kw::Invalid {
|
|
let ty_snip = cx
|
|
.sess
|
|
.source_map()
|
|
.span_to_snippet(arg.ty.span);
|
|
|
|
let (ty_snip, appl) = if let Ok(snip) = ty_snip {
|
|
(snip, Applicability::MachineApplicable)
|
|
} else {
|
|
("<type>".to_owned(), Applicability::HasPlaceholders)
|
|
};
|
|
|
|
cx.struct_span_lint(
|
|
ANONYMOUS_PARAMETERS,
|
|
arg.pat.span,
|
|
"anonymous parameters are deprecated and will be \
|
|
removed in the next edition."
|
|
).span_suggestion(
|
|
arg.pat.span,
|
|
"Try naming the parameter or explicitly \
|
|
ignoring it",
|
|
format!("_: {}", ty_snip),
|
|
appl
|
|
).emit();
|
|
}
|
|
}
|
|
_ => (),
|
|
}
|
|
}
|
|
},
|
|
_ => (),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Check for use of attributes which have been deprecated.
|
|
#[derive(Clone)]
|
|
pub struct DeprecatedAttr {
|
|
// This is not free to compute, so we want to keep it around, rather than
|
|
// compute it for every attribute.
|
|
depr_attrs: Vec<&'static (Symbol, AttributeType, AttributeTemplate, AttributeGate)>,
|
|
}
|
|
|
|
impl_lint_pass!(DeprecatedAttr => []);
|
|
|
|
impl DeprecatedAttr {
|
|
pub fn new() -> DeprecatedAttr {
|
|
DeprecatedAttr {
|
|
depr_attrs: deprecated_attributes(),
|
|
}
|
|
}
|
|
}
|
|
|
|
fn lint_deprecated_attr(
|
|
cx: &EarlyContext<'_>,
|
|
attr: &ast::Attribute,
|
|
msg: &str,
|
|
suggestion: Option<&str>,
|
|
) {
|
|
cx.struct_span_lint(DEPRECATED, attr.span, &msg)
|
|
.span_suggestion_short(
|
|
attr.span,
|
|
suggestion.unwrap_or("remove this attribute"),
|
|
String::new(),
|
|
Applicability::MachineApplicable
|
|
)
|
|
.emit();
|
|
}
|
|
|
|
impl EarlyLintPass for DeprecatedAttr {
|
|
fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &ast::Attribute) {
|
|
for &&(n, _, _, ref g) in &self.depr_attrs {
|
|
if attr.ident().map(|ident| ident.name) == Some(n) {
|
|
if let &AttributeGate::Gated(Stability::Deprecated(link, suggestion),
|
|
ref name,
|
|
ref reason,
|
|
_) = g {
|
|
let msg = format!("use of deprecated attribute `{}`: {}. See {}",
|
|
name, reason, link);
|
|
lint_deprecated_attr(cx, attr, &msg, suggestion);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
if attr.check_name(sym::no_start) || attr.check_name(sym::crate_id) {
|
|
let path_str = pprust::path_to_string(&attr.get_normal_item().path);
|
|
let msg = format!("use of deprecated attribute `{}`: no longer used.", path_str);
|
|
lint_deprecated_attr(cx, attr, &msg, None);
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub UNUSED_DOC_COMMENTS,
|
|
Warn,
|
|
"detects doc comments that aren't used by rustdoc"
|
|
}
|
|
|
|
declare_lint_pass!(UnusedDocComment => [UNUSED_DOC_COMMENTS]);
|
|
|
|
impl UnusedDocComment {
|
|
fn warn_if_doc(
|
|
&self,
|
|
cx: &EarlyContext<'_>,
|
|
node_span: Span,
|
|
node_kind: &str,
|
|
is_macro_expansion: bool,
|
|
attrs: &[ast::Attribute]
|
|
) {
|
|
let mut attrs = attrs.into_iter().peekable();
|
|
|
|
// Accumulate a single span for sugared doc comments.
|
|
let mut sugared_span: Option<Span> = None;
|
|
|
|
while let Some(attr) = attrs.next() {
|
|
if attr.is_doc_comment() {
|
|
sugared_span = Some(
|
|
sugared_span.map_or_else(
|
|
|| attr.span,
|
|
|span| span.with_hi(attr.span.hi()),
|
|
),
|
|
);
|
|
}
|
|
|
|
if attrs.peek().map(|next_attr| next_attr.is_doc_comment()).unwrap_or_default() {
|
|
continue;
|
|
}
|
|
|
|
let span = sugared_span.take().unwrap_or_else(|| attr.span);
|
|
|
|
if attr.check_name(sym::doc) {
|
|
let mut err = cx.struct_span_lint(UNUSED_DOC_COMMENTS, span, "unused doc comment");
|
|
|
|
err.span_label(
|
|
node_span,
|
|
format!("rustdoc does not generate documentation for {}", node_kind)
|
|
);
|
|
|
|
if is_macro_expansion {
|
|
err.help("to document an item produced by a macro, \
|
|
the macro must produce the documentation as part of its expansion");
|
|
}
|
|
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl EarlyLintPass for UnusedDocComment {
|
|
fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
|
|
if let ast::ItemKind::Mac(..) = item.kind {
|
|
self.warn_if_doc(cx, item.span, "macro expansions", true, &item.attrs);
|
|
}
|
|
}
|
|
|
|
fn check_stmt(&mut self, cx: &EarlyContext<'_>, stmt: &ast::Stmt) {
|
|
let (kind, is_macro_expansion) = match stmt.kind {
|
|
ast::StmtKind::Local(..) => ("statements", false),
|
|
ast::StmtKind::Item(..) => ("inner items", false),
|
|
ast::StmtKind::Mac(..) => ("macro expansions", true),
|
|
// expressions will be reported by `check_expr`.
|
|
ast::StmtKind::Semi(..) |
|
|
ast::StmtKind::Expr(..) => return,
|
|
};
|
|
|
|
self.warn_if_doc(cx, stmt.span, kind, is_macro_expansion, stmt.kind.attrs());
|
|
}
|
|
|
|
fn check_arm(&mut self, cx: &EarlyContext<'_>, arm: &ast::Arm) {
|
|
let arm_span = arm.pat.span.with_hi(arm.body.span.hi());
|
|
self.warn_if_doc(cx, arm_span, "match arms", false, &arm.attrs);
|
|
}
|
|
|
|
fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
|
|
self.warn_if_doc(cx, expr.span, "expressions", false, &expr.attrs);
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
NO_MANGLE_CONST_ITEMS,
|
|
Deny,
|
|
"const items will not have their symbols exported"
|
|
}
|
|
|
|
declare_lint! {
|
|
NO_MANGLE_GENERIC_ITEMS,
|
|
Warn,
|
|
"generic items must be mangled"
|
|
}
|
|
|
|
declare_lint_pass!(InvalidNoMangleItems => [NO_MANGLE_CONST_ITEMS, NO_MANGLE_GENERIC_ITEMS]);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidNoMangleItems {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item) {
|
|
match it.kind {
|
|
hir::ItemKind::Fn(.., ref generics, _) => {
|
|
if let Some(no_mangle_attr) = attr::find_by_name(&it.attrs, sym::no_mangle) {
|
|
for param in &generics.params {
|
|
match param.kind {
|
|
GenericParamKind::Lifetime { .. } => {}
|
|
GenericParamKind::Type { .. } |
|
|
GenericParamKind::Const { .. } => {
|
|
let mut err = cx.struct_span_lint(
|
|
NO_MANGLE_GENERIC_ITEMS,
|
|
it.span,
|
|
"functions generic over types or consts must be mangled",
|
|
);
|
|
err.span_suggestion_short(
|
|
no_mangle_attr.span,
|
|
"remove this attribute",
|
|
String::new(),
|
|
// Use of `#[no_mangle]` suggests FFI intent; correct
|
|
// fix may be to monomorphize source by hand
|
|
Applicability::MaybeIncorrect
|
|
);
|
|
err.emit();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
hir::ItemKind::Const(..) => {
|
|
if attr::contains_name(&it.attrs, sym::no_mangle) {
|
|
// Const items do not refer to a particular location in memory, and therefore
|
|
// don't have anything to attach a symbol to
|
|
let msg = "const items should never be `#[no_mangle]`";
|
|
let mut err = cx.struct_span_lint(NO_MANGLE_CONST_ITEMS, it.span, msg);
|
|
|
|
// account for "pub const" (#45562)
|
|
let start = cx.tcx.sess.source_map().span_to_snippet(it.span)
|
|
.map(|snippet| snippet.find("const").unwrap_or(0))
|
|
.unwrap_or(0) as u32;
|
|
// `const` is 5 chars
|
|
let const_span = it.span.with_hi(BytePos(it.span.lo().0 + start + 5));
|
|
err.span_suggestion(
|
|
const_span,
|
|
"try a static value",
|
|
"pub static".to_owned(),
|
|
Applicability::MachineApplicable
|
|
);
|
|
err.emit();
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
MUTABLE_TRANSMUTES,
|
|
Deny,
|
|
"mutating transmuted &mut T from &T may cause undefined behavior"
|
|
}
|
|
|
|
declare_lint_pass!(MutableTransmutes => [MUTABLE_TRANSMUTES]);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MutableTransmutes {
|
|
fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &hir::Expr) {
|
|
use rustc_target::spec::abi::Abi::RustIntrinsic;
|
|
|
|
let msg = "mutating transmuted &mut T from &T may cause undefined behavior, \
|
|
consider instead using an UnsafeCell";
|
|
match get_transmute_from_to(cx, expr).map(|(ty1, ty2)| (&ty1.kind, &ty2.kind)) {
|
|
Some((&ty::Ref(_, _, from_mt), &ty::Ref(_, _, to_mt))) => {
|
|
if to_mt == hir::Mutability::Mut &&
|
|
from_mt == hir::Mutability::Not {
|
|
cx.span_lint(MUTABLE_TRANSMUTES, expr.span, msg);
|
|
}
|
|
}
|
|
_ => (),
|
|
}
|
|
|
|
fn get_transmute_from_to<'a, 'tcx>
|
|
(cx: &LateContext<'a, 'tcx>,
|
|
expr: &hir::Expr)
|
|
-> Option<(Ty<'tcx>, Ty<'tcx>)> {
|
|
let def = if let hir::ExprKind::Path(ref qpath) = expr.kind {
|
|
cx.tables.qpath_res(qpath, expr.hir_id)
|
|
} else {
|
|
return None;
|
|
};
|
|
if let Res::Def(DefKind::Fn, did) = def {
|
|
if !def_id_is_transmute(cx, did) {
|
|
return None;
|
|
}
|
|
let sig = cx.tables.node_type(expr.hir_id).fn_sig(cx.tcx);
|
|
let from = sig.inputs().skip_binder()[0];
|
|
let to = *sig.output().skip_binder();
|
|
return Some((from, to));
|
|
}
|
|
None
|
|
}
|
|
|
|
fn def_id_is_transmute(cx: &LateContext<'_, '_>, def_id: DefId) -> bool {
|
|
cx.tcx.fn_sig(def_id).abi() == RustIntrinsic &&
|
|
cx.tcx.item_name(def_id) == sym::transmute
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
UNSTABLE_FEATURES,
|
|
Allow,
|
|
"enabling unstable features (deprecated. do not use)"
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Forbids using the `#[feature(...)]` attribute
|
|
UnstableFeatures => [UNSTABLE_FEATURES]
|
|
);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnstableFeatures {
|
|
fn check_attribute(&mut self, ctx: &LateContext<'_, '_>, attr: &ast::Attribute) {
|
|
if attr.check_name(sym::feature) {
|
|
if let Some(items) = attr.meta_item_list() {
|
|
for item in items {
|
|
ctx.span_lint(UNSTABLE_FEATURES, item.span(), "unstable feature");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub UNREACHABLE_PUB,
|
|
Allow,
|
|
"`pub` items not reachable from crate root"
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Lint for items marked `pub` that aren't reachable from other crates.
|
|
UnreachablePub => [UNREACHABLE_PUB]
|
|
);
|
|
|
|
impl UnreachablePub {
|
|
fn perform_lint(&self, cx: &LateContext<'_, '_>, what: &str, id: hir::HirId,
|
|
vis: &hir::Visibility, span: Span, exportable: bool) {
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
match vis.node {
|
|
hir::VisibilityKind::Public if !cx.access_levels.is_reachable(id) => {
|
|
if span.from_expansion() {
|
|
applicability = Applicability::MaybeIncorrect;
|
|
}
|
|
let def_span = cx.tcx.sess.source_map().def_span(span);
|
|
let mut err = cx.struct_span_lint(UNREACHABLE_PUB, def_span,
|
|
&format!("unreachable `pub` {}", what));
|
|
let replacement = if cx.tcx.features().crate_visibility_modifier {
|
|
"crate"
|
|
} else {
|
|
"pub(crate)"
|
|
}.to_owned();
|
|
|
|
err.span_suggestion(
|
|
vis.span,
|
|
"consider restricting its visibility",
|
|
replacement,
|
|
applicability,
|
|
);
|
|
if exportable {
|
|
err.help("or consider exporting it for use by other crates");
|
|
}
|
|
err.emit();
|
|
},
|
|
_ => {}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnreachablePub {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::Item) {
|
|
self.perform_lint(cx, "item", item.hir_id, &item.vis, item.span, true);
|
|
}
|
|
|
|
fn check_foreign_item(&mut self, cx: &LateContext<'_, '_>, foreign_item: &hir::ForeignItem) {
|
|
self.perform_lint(cx, "item", foreign_item.hir_id, &foreign_item.vis,
|
|
foreign_item.span, true);
|
|
}
|
|
|
|
fn check_struct_field(&mut self, cx: &LateContext<'_, '_>, field: &hir::StructField) {
|
|
self.perform_lint(cx, "field", field.hir_id, &field.vis, field.span, false);
|
|
}
|
|
|
|
fn check_impl_item(&mut self, cx: &LateContext<'_, '_>, impl_item: &hir::ImplItem) {
|
|
self.perform_lint(cx, "item", impl_item.hir_id, &impl_item.vis, impl_item.span, false);
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
TYPE_ALIAS_BOUNDS,
|
|
Warn,
|
|
"bounds in type aliases are not enforced"
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Lint for trait and lifetime bounds in type aliases being mostly ignored.
|
|
/// They are relevant when using associated types, but otherwise neither checked
|
|
/// at definition site nor enforced at use site.
|
|
TypeAliasBounds => [TYPE_ALIAS_BOUNDS]
|
|
);
|
|
|
|
impl TypeAliasBounds {
|
|
fn is_type_variable_assoc(qpath: &hir::QPath) -> bool {
|
|
match *qpath {
|
|
hir::QPath::TypeRelative(ref ty, _) => {
|
|
// If this is a type variable, we found a `T::Assoc`.
|
|
match ty.kind {
|
|
hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) => {
|
|
match path.res {
|
|
Res::Def(DefKind::TyParam, _) => true,
|
|
_ => false
|
|
}
|
|
}
|
|
_ => false
|
|
}
|
|
}
|
|
hir::QPath::Resolved(..) => false,
|
|
}
|
|
}
|
|
|
|
fn suggest_changing_assoc_types(ty: &hir::Ty, err: &mut DiagnosticBuilder<'_>) {
|
|
// Access to associates types should use `<T as Bound>::Assoc`, which does not need a
|
|
// bound. Let's see if this type does that.
|
|
|
|
// We use a HIR visitor to walk the type.
|
|
use rustc::hir::intravisit::{self, Visitor};
|
|
struct WalkAssocTypes<'a, 'db> {
|
|
err: &'a mut DiagnosticBuilder<'db>
|
|
}
|
|
impl<'a, 'db, 'v> Visitor<'v> for WalkAssocTypes<'a, 'db> {
|
|
fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'v>
|
|
{
|
|
intravisit::NestedVisitorMap::None
|
|
}
|
|
|
|
fn visit_qpath(&mut self, qpath: &'v hir::QPath, id: hir::HirId, span: Span) {
|
|
if TypeAliasBounds::is_type_variable_assoc(qpath) {
|
|
self.err.span_help(span,
|
|
"use fully disambiguated paths (i.e., `<T as Trait>::Assoc`) to refer to \
|
|
associated types in type aliases");
|
|
}
|
|
intravisit::walk_qpath(self, qpath, id, span)
|
|
}
|
|
}
|
|
|
|
// Let's go for a walk!
|
|
let mut visitor = WalkAssocTypes { err };
|
|
visitor.visit_ty(ty);
|
|
}
|
|
}
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TypeAliasBounds {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &hir::Item) {
|
|
let (ty, type_alias_generics) = match item.kind {
|
|
hir::ItemKind::TyAlias(ref ty, ref generics) => (&*ty, generics),
|
|
_ => return,
|
|
};
|
|
let mut suggested_changing_assoc_types = false;
|
|
// There must not be a where clause
|
|
if !type_alias_generics.where_clause.predicates.is_empty() {
|
|
let spans : Vec<_> = type_alias_generics.where_clause.predicates.iter()
|
|
.map(|pred| pred.span()).collect();
|
|
let mut err = cx.struct_span_lint(TYPE_ALIAS_BOUNDS, spans,
|
|
"where clauses are not enforced in type aliases");
|
|
err.span_suggestion(
|
|
type_alias_generics.where_clause.span_for_predicates_or_empty_place(),
|
|
"the clause will not be checked when the type alias is used, and should be removed",
|
|
String::new(),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
if !suggested_changing_assoc_types {
|
|
TypeAliasBounds::suggest_changing_assoc_types(ty, &mut err);
|
|
suggested_changing_assoc_types = true;
|
|
}
|
|
err.emit();
|
|
}
|
|
// The parameters must not have bounds
|
|
for param in type_alias_generics.params.iter() {
|
|
let spans: Vec<_> = param.bounds.iter().map(|b| b.span()).collect();
|
|
let suggestion = spans.iter().map(|sp| {
|
|
let start = param.span.between(*sp); // Include the `:` in `T: Bound`.
|
|
(start.to(*sp), String::new())
|
|
}).collect();
|
|
if !spans.is_empty() {
|
|
let mut err = cx.struct_span_lint(
|
|
TYPE_ALIAS_BOUNDS,
|
|
spans,
|
|
"bounds on generic parameters are not enforced in type aliases",
|
|
);
|
|
let msg = "the bound will not be checked when the type alias is used, \
|
|
and should be removed";
|
|
err.multipart_suggestion(&msg, suggestion, Applicability::MachineApplicable);
|
|
if !suggested_changing_assoc_types {
|
|
TypeAliasBounds::suggest_changing_assoc_types(ty, &mut err);
|
|
suggested_changing_assoc_types = true;
|
|
}
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Lint constants that are erroneous.
|
|
/// Without this lint, we might not get any diagnostic if the constant is
|
|
/// unused within this crate, even though downstream crates can't use it
|
|
/// without producing an error.
|
|
UnusedBrokenConst => []
|
|
);
|
|
|
|
fn check_const(cx: &LateContext<'_, '_>, body_id: hir::BodyId) {
|
|
let def_id = cx.tcx.hir().body_owner_def_id(body_id);
|
|
let param_env = if cx.tcx.is_static(def_id) {
|
|
// Use the same param_env as `codegen_static_initializer`, to reuse the cache.
|
|
ty::ParamEnv::reveal_all()
|
|
} else {
|
|
cx.tcx.param_env(def_id)
|
|
};
|
|
let cid = ::rustc::mir::interpret::GlobalId {
|
|
instance: ty::Instance::mono(cx.tcx, def_id),
|
|
promoted: None
|
|
};
|
|
// trigger the query once for all constants since that will already report the errors
|
|
// FIXME: Use ensure here
|
|
let _ = cx.tcx.const_eval(param_env.and(cid));
|
|
}
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnusedBrokenConst {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item) {
|
|
match it.kind {
|
|
hir::ItemKind::Const(_, body_id) => {
|
|
check_const(cx, body_id);
|
|
},
|
|
hir::ItemKind::Static(_, _, body_id) => {
|
|
check_const(cx, body_id);
|
|
},
|
|
_ => {},
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
TRIVIAL_BOUNDS,
|
|
Warn,
|
|
"these bounds don't depend on an type parameters"
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Lint for trait and lifetime bounds that don't depend on type parameters
|
|
/// which either do nothing, or stop the item from being used.
|
|
TrivialConstraints => [TRIVIAL_BOUNDS]
|
|
);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TrivialConstraints {
|
|
fn check_item(
|
|
&mut self,
|
|
cx: &LateContext<'a, 'tcx>,
|
|
item: &'tcx hir::Item,
|
|
) {
|
|
use rustc::ty::fold::TypeFoldable;
|
|
use rustc::ty::Predicate::*;
|
|
|
|
if cx.tcx.features().trivial_bounds {
|
|
let def_id = cx.tcx.hir().local_def_id(item.hir_id);
|
|
let predicates = cx.tcx.predicates_of(def_id);
|
|
for &(predicate, span) in predicates.predicates {
|
|
let predicate_kind_name = match predicate {
|
|
Trait(..) => "Trait",
|
|
TypeOutlives(..) |
|
|
RegionOutlives(..) => "Lifetime",
|
|
|
|
// Ignore projections, as they can only be global
|
|
// if the trait bound is global
|
|
Projection(..) |
|
|
// Ignore bounds that a user can't type
|
|
WellFormed(..) |
|
|
ObjectSafe(..) |
|
|
ClosureKind(..) |
|
|
Subtype(..) |
|
|
ConstEvaluatable(..) => continue,
|
|
};
|
|
if predicate.is_global() {
|
|
cx.span_lint(
|
|
TRIVIAL_BOUNDS,
|
|
span,
|
|
&format!("{} bound {} does not depend on any type \
|
|
or lifetime parameters", predicate_kind_name, predicate),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Does nothing as a lint pass, but registers some `Lint`s
|
|
/// which are used by other parts of the compiler.
|
|
SoftLints => [
|
|
WHILE_TRUE,
|
|
BOX_POINTERS,
|
|
NON_SHORTHAND_FIELD_PATTERNS,
|
|
UNSAFE_CODE,
|
|
MISSING_DOCS,
|
|
MISSING_COPY_IMPLEMENTATIONS,
|
|
MISSING_DEBUG_IMPLEMENTATIONS,
|
|
ANONYMOUS_PARAMETERS,
|
|
UNUSED_DOC_COMMENTS,
|
|
NO_MANGLE_CONST_ITEMS,
|
|
NO_MANGLE_GENERIC_ITEMS,
|
|
MUTABLE_TRANSMUTES,
|
|
UNSTABLE_FEATURES,
|
|
UNREACHABLE_PUB,
|
|
TYPE_ALIAS_BOUNDS,
|
|
TRIVIAL_BOUNDS
|
|
]
|
|
);
|
|
|
|
declare_lint! {
|
|
pub ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
|
|
Warn,
|
|
"`...` range patterns are deprecated"
|
|
}
|
|
|
|
#[derive(Default)]
|
|
pub struct EllipsisInclusiveRangePatterns {
|
|
/// If `Some(_)`, suppress all subsequent pattern
|
|
/// warnings for better diagnostics.
|
|
node_id: Option<ast::NodeId>,
|
|
}
|
|
|
|
impl_lint_pass!(EllipsisInclusiveRangePatterns => [ELLIPSIS_INCLUSIVE_RANGE_PATTERNS]);
|
|
|
|
impl EarlyLintPass for EllipsisInclusiveRangePatterns {
|
|
fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &ast::Pat) {
|
|
if self.node_id.is_some() {
|
|
// Don't recursively warn about patterns inside range endpoints.
|
|
return
|
|
}
|
|
|
|
use self::ast::{PatKind, RangeEnd, RangeSyntax::DotDotDot};
|
|
|
|
/// If `pat` is a `...` pattern, return the start and end of the range, as well as the span
|
|
/// corresponding to the ellipsis.
|
|
fn matches_ellipsis_pat(pat: &ast::Pat) -> Option<(&P<Expr>, &P<Expr>, Span)> {
|
|
match &pat.kind {
|
|
PatKind::Range(a, b, Spanned { span, node: RangeEnd::Included(DotDotDot), .. }) => {
|
|
Some((a, b, *span))
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
let (parenthesise, endpoints) = match &pat.kind {
|
|
PatKind::Ref(subpat, _) => (true, matches_ellipsis_pat(&subpat)),
|
|
_ => (false, matches_ellipsis_pat(pat)),
|
|
};
|
|
|
|
if let Some((start, end, join)) = endpoints {
|
|
let msg = "`...` range patterns are deprecated";
|
|
let suggestion = "use `..=` for an inclusive range";
|
|
if parenthesise {
|
|
self.node_id = Some(pat.id);
|
|
let mut err = cx.struct_span_lint(ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, pat.span, msg);
|
|
err.span_suggestion(
|
|
pat.span,
|
|
suggestion,
|
|
format!("&({}..={})", expr_to_string(&start), expr_to_string(&end)),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
err.emit();
|
|
} else {
|
|
let mut err = cx.struct_span_lint(ELLIPSIS_INCLUSIVE_RANGE_PATTERNS, join, msg);
|
|
err.span_suggestion_short(
|
|
join,
|
|
suggestion,
|
|
"..=".to_owned(),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
err.emit();
|
|
};
|
|
}
|
|
}
|
|
|
|
fn check_pat_post(&mut self, _cx: &EarlyContext<'_>, pat: &ast::Pat) {
|
|
if let Some(node_id) = self.node_id {
|
|
if pat.id == node_id {
|
|
self.node_id = None
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
UNNAMEABLE_TEST_ITEMS,
|
|
Warn,
|
|
"detects an item that cannot be named being marked as `#[test_case]`",
|
|
report_in_external_macro
|
|
}
|
|
|
|
pub struct UnnameableTestItems {
|
|
boundary: hir::HirId, // HirId of the item under which things are not nameable
|
|
items_nameable: bool,
|
|
}
|
|
|
|
impl_lint_pass!(UnnameableTestItems => [UNNAMEABLE_TEST_ITEMS]);
|
|
|
|
impl UnnameableTestItems {
|
|
pub fn new() -> Self {
|
|
Self {
|
|
boundary: hir::DUMMY_HIR_ID,
|
|
items_nameable: true
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnnameableTestItems {
|
|
fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item) {
|
|
if self.items_nameable {
|
|
if let hir::ItemKind::Mod(..) = it.kind {}
|
|
else {
|
|
self.items_nameable = false;
|
|
self.boundary = it.hir_id;
|
|
}
|
|
return;
|
|
}
|
|
|
|
if let Some(attr) = attr::find_by_name(&it.attrs, sym::rustc_test_marker) {
|
|
cx.struct_span_lint(
|
|
UNNAMEABLE_TEST_ITEMS,
|
|
attr.span,
|
|
"cannot test inner items",
|
|
).emit();
|
|
}
|
|
}
|
|
|
|
fn check_item_post(&mut self, _cx: &LateContext<'_, '_>, it: &hir::Item) {
|
|
if !self.items_nameable && self.boundary == it.hir_id {
|
|
self.items_nameable = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub KEYWORD_IDENTS,
|
|
Allow,
|
|
"detects edition keywords being used as an identifier",
|
|
@future_incompatible = FutureIncompatibleInfo {
|
|
reference: "issue #49716 <https://github.com/rust-lang/rust/issues/49716>",
|
|
edition: Some(Edition::Edition2018),
|
|
};
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Check for uses of edition keywords used as an identifier.
|
|
KeywordIdents => [KEYWORD_IDENTS]
|
|
);
|
|
|
|
struct UnderMacro(bool);
|
|
|
|
impl KeywordIdents {
|
|
fn check_tokens(&mut self, cx: &EarlyContext<'_>, tokens: TokenStream) {
|
|
for tt in tokens.into_trees() {
|
|
match tt {
|
|
// Only report non-raw idents.
|
|
TokenTree::Token(token) => if let Some((ident, false)) = token.ident() {
|
|
self.check_ident_token(cx, UnderMacro(true), ident);
|
|
}
|
|
TokenTree::Delimited(_, _, tts) => {
|
|
self.check_tokens(cx, tts)
|
|
},
|
|
}
|
|
}
|
|
}
|
|
|
|
fn check_ident_token(&mut self,
|
|
cx: &EarlyContext<'_>,
|
|
UnderMacro(under_macro): UnderMacro,
|
|
ident: ast::Ident)
|
|
{
|
|
let next_edition = match cx.sess.edition() {
|
|
Edition::Edition2015 => {
|
|
match ident.name {
|
|
kw::Async | kw::Await | kw::Try => Edition::Edition2018,
|
|
|
|
// rust-lang/rust#56327: Conservatively do not
|
|
// attempt to report occurrences of `dyn` within
|
|
// macro definitions or invocations, because `dyn`
|
|
// can legitimately occur as a contextual keyword
|
|
// in 2015 code denoting its 2018 meaning, and we
|
|
// do not want rustfix to inject bugs into working
|
|
// code by rewriting such occurrences.
|
|
//
|
|
// But if we see `dyn` outside of a macro, we know
|
|
// its precise role in the parsed AST and thus are
|
|
// assured this is truly an attempt to use it as
|
|
// an identifier.
|
|
kw::Dyn if !under_macro => Edition::Edition2018,
|
|
|
|
_ => return,
|
|
}
|
|
}
|
|
|
|
// There are no new keywords yet for the 2018 edition and beyond.
|
|
_ => return,
|
|
};
|
|
|
|
// Don't lint `r#foo`.
|
|
if cx.sess.parse_sess.raw_identifier_spans.borrow().contains(&ident.span) {
|
|
return;
|
|
}
|
|
|
|
let mut lint = cx.struct_span_lint(
|
|
KEYWORD_IDENTS,
|
|
ident.span,
|
|
&format!("`{}` is a keyword in the {} edition", ident, next_edition),
|
|
);
|
|
lint.span_suggestion(
|
|
ident.span,
|
|
"you can use a raw identifier to stay compatible",
|
|
format!("r#{}", ident),
|
|
Applicability::MachineApplicable,
|
|
);
|
|
lint.emit()
|
|
}
|
|
}
|
|
|
|
impl EarlyLintPass for KeywordIdents {
|
|
fn check_mac_def(&mut self, cx: &EarlyContext<'_>, mac_def: &ast::MacroDef, _id: ast::NodeId) {
|
|
self.check_tokens(cx, mac_def.body.inner_tokens());
|
|
}
|
|
fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::Mac) {
|
|
self.check_tokens(cx, mac.args.inner_tokens());
|
|
}
|
|
fn check_ident(&mut self, cx: &EarlyContext<'_>, ident: ast::Ident) {
|
|
self.check_ident_token(cx, UnderMacro(false), ident);
|
|
}
|
|
}
|
|
|
|
declare_lint_pass!(ExplicitOutlivesRequirements => [EXPLICIT_OUTLIVES_REQUIREMENTS]);
|
|
|
|
impl ExplicitOutlivesRequirements {
|
|
fn lifetimes_outliving_lifetime<'tcx>(
|
|
inferred_outlives: &'tcx [(ty::Predicate<'tcx>, Span)],
|
|
index: u32,
|
|
) -> Vec<ty::Region<'tcx>> {
|
|
inferred_outlives.iter().filter_map(|(pred, _)| {
|
|
match pred {
|
|
ty::Predicate::RegionOutlives(outlives) => {
|
|
let outlives = outlives.skip_binder();
|
|
match outlives.0 {
|
|
ty::ReEarlyBound(ebr) if ebr.index == index => {
|
|
Some(outlives.1)
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
_ => None
|
|
}
|
|
}).collect()
|
|
}
|
|
|
|
fn lifetimes_outliving_type<'tcx>(
|
|
inferred_outlives: &'tcx [(ty::Predicate<'tcx>, Span)],
|
|
index: u32,
|
|
) -> Vec<ty::Region<'tcx>> {
|
|
inferred_outlives.iter().filter_map(|(pred, _)| {
|
|
match pred {
|
|
ty::Predicate::TypeOutlives(outlives) => {
|
|
let outlives = outlives.skip_binder();
|
|
outlives.0.is_param(index).then_some(outlives.1)
|
|
}
|
|
_ => None
|
|
}
|
|
}).collect()
|
|
}
|
|
|
|
fn collect_outlived_lifetimes<'tcx>(
|
|
&self,
|
|
param: &'tcx hir::GenericParam,
|
|
tcx: TyCtxt<'tcx>,
|
|
inferred_outlives: &'tcx [(ty::Predicate<'tcx>, Span)],
|
|
ty_generics: &'tcx ty::Generics,
|
|
) -> Vec<ty::Region<'tcx>> {
|
|
let index = ty_generics.param_def_id_to_index[
|
|
&tcx.hir().local_def_id(param.hir_id)];
|
|
|
|
match param.kind {
|
|
hir::GenericParamKind::Lifetime { .. } => {
|
|
Self::lifetimes_outliving_lifetime(inferred_outlives, index)
|
|
}
|
|
hir::GenericParamKind::Type { .. } => {
|
|
Self::lifetimes_outliving_type(inferred_outlives, index)
|
|
}
|
|
hir::GenericParamKind::Const { .. } => Vec::new(),
|
|
}
|
|
}
|
|
|
|
|
|
fn collect_outlives_bound_spans<'tcx>(
|
|
&self,
|
|
tcx: TyCtxt<'tcx>,
|
|
bounds: &hir::GenericBounds,
|
|
inferred_outlives: &[ty::Region<'tcx>],
|
|
infer_static: bool,
|
|
) -> Vec<(usize, Span)> {
|
|
use rustc::middle::resolve_lifetime::Region;
|
|
|
|
bounds
|
|
.iter()
|
|
.enumerate()
|
|
.filter_map(|(i, bound)| {
|
|
if let hir::GenericBound::Outlives(lifetime) = bound {
|
|
let is_inferred = match tcx.named_region(lifetime.hir_id) {
|
|
Some(Region::Static) if infer_static => {
|
|
inferred_outlives.iter()
|
|
.any(|r| if let ty::ReStatic = r { true } else { false })
|
|
}
|
|
Some(Region::EarlyBound(index, ..)) => inferred_outlives
|
|
.iter()
|
|
.any(|r| {
|
|
if let ty::ReEarlyBound(ebr) = r {
|
|
ebr.index == index
|
|
} else {
|
|
false
|
|
}
|
|
}),
|
|
_ => false,
|
|
};
|
|
is_inferred.then_some((i, bound.span()))
|
|
} else {
|
|
None
|
|
}
|
|
})
|
|
.collect()
|
|
}
|
|
|
|
fn consolidate_outlives_bound_spans(
|
|
&self,
|
|
lo: Span,
|
|
bounds: &hir::GenericBounds,
|
|
bound_spans: Vec<(usize, Span)>
|
|
) -> Vec<Span> {
|
|
if bounds.is_empty() {
|
|
return Vec::new();
|
|
}
|
|
if bound_spans.len() == bounds.len() {
|
|
let (_, last_bound_span) = bound_spans[bound_spans.len()-1];
|
|
// If all bounds are inferable, we want to delete the colon, so
|
|
// start from just after the parameter (span passed as argument)
|
|
vec![lo.to(last_bound_span)]
|
|
} else {
|
|
let mut merged = Vec::new();
|
|
let mut last_merged_i = None;
|
|
|
|
let mut from_start = true;
|
|
for (i, bound_span) in bound_spans {
|
|
match last_merged_i {
|
|
// If the first bound is inferable, our span should also eat the leading `+`.
|
|
None if i == 0 => {
|
|
merged.push(bound_span.to(bounds[1].span().shrink_to_lo()));
|
|
last_merged_i = Some(0);
|
|
},
|
|
// If consecutive bounds are inferable, merge their spans
|
|
Some(h) if i == h+1 => {
|
|
if let Some(tail) = merged.last_mut() {
|
|
// Also eat the trailing `+` if the first
|
|
// more-than-one bound is inferable
|
|
let to_span = if from_start && i < bounds.len() {
|
|
bounds[i+1].span().shrink_to_lo()
|
|
} else {
|
|
bound_span
|
|
};
|
|
*tail = tail.to(to_span);
|
|
last_merged_i = Some(i);
|
|
} else {
|
|
bug!("another bound-span visited earlier");
|
|
}
|
|
},
|
|
_ => {
|
|
// When we find a non-inferable bound, subsequent inferable bounds
|
|
// won't be consecutive from the start (and we'll eat the leading
|
|
// `+` rather than the trailing one)
|
|
from_start = false;
|
|
merged.push(bounds[i-1].span().shrink_to_hi().to(bound_span));
|
|
last_merged_i = Some(i);
|
|
}
|
|
}
|
|
}
|
|
merged
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ExplicitOutlivesRequirements {
|
|
fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item) {
|
|
use rustc::middle::resolve_lifetime::Region;
|
|
|
|
let infer_static = cx.tcx.features().infer_static_outlives_requirements;
|
|
let def_id = cx.tcx.hir().local_def_id(item.hir_id);
|
|
if let hir::ItemKind::Struct(_, ref hir_generics)
|
|
| hir::ItemKind::Enum(_, ref hir_generics)
|
|
| hir::ItemKind::Union(_, ref hir_generics) = item.kind
|
|
{
|
|
let inferred_outlives = cx.tcx.inferred_outlives_of(def_id);
|
|
if inferred_outlives.is_empty() {
|
|
return;
|
|
}
|
|
|
|
let ty_generics = cx.tcx.generics_of(def_id);
|
|
|
|
let mut bound_count = 0;
|
|
let mut lint_spans = Vec::new();
|
|
|
|
for param in &hir_generics.params {
|
|
let has_lifetime_bounds = param.bounds.iter().any(|bound| {
|
|
if let hir::GenericBound::Outlives(_) = bound {
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
});
|
|
if !has_lifetime_bounds {
|
|
continue;
|
|
}
|
|
|
|
let relevant_lifetimes = self.collect_outlived_lifetimes(
|
|
param,
|
|
cx.tcx,
|
|
inferred_outlives,
|
|
ty_generics,
|
|
);
|
|
if relevant_lifetimes.is_empty() {
|
|
continue;
|
|
}
|
|
|
|
let bound_spans = self.collect_outlives_bound_spans(
|
|
cx.tcx, ¶m.bounds, &relevant_lifetimes, infer_static,
|
|
);
|
|
bound_count += bound_spans.len();
|
|
lint_spans.extend(
|
|
self.consolidate_outlives_bound_spans(
|
|
param.span.shrink_to_hi(), ¶m.bounds, bound_spans
|
|
)
|
|
);
|
|
}
|
|
|
|
let mut where_lint_spans = Vec::new();
|
|
let mut dropped_predicate_count = 0;
|
|
let num_predicates = hir_generics.where_clause.predicates.len();
|
|
for (i, where_predicate) in hir_generics.where_clause.predicates.iter().enumerate() {
|
|
let (relevant_lifetimes, bounds, span) = match where_predicate {
|
|
hir::WherePredicate::RegionPredicate(predicate) => {
|
|
if let Some(Region::EarlyBound(index, ..))
|
|
= cx.tcx.named_region(predicate.lifetime.hir_id)
|
|
{
|
|
(
|
|
Self::lifetimes_outliving_lifetime(inferred_outlives, index),
|
|
&predicate.bounds,
|
|
predicate.span,
|
|
)
|
|
} else {
|
|
continue;
|
|
}
|
|
}
|
|
hir::WherePredicate::BoundPredicate(predicate) => {
|
|
// FIXME we can also infer bounds on associated types,
|
|
// and should check for them here.
|
|
match predicate.bounded_ty.kind {
|
|
hir::TyKind::Path(hir::QPath::Resolved(
|
|
None,
|
|
ref path,
|
|
)) => {
|
|
if let Res::Def(DefKind::TyParam, def_id) = path.res {
|
|
let index = ty_generics.param_def_id_to_index[&def_id];
|
|
(
|
|
Self::lifetimes_outliving_type(inferred_outlives, index),
|
|
&predicate.bounds,
|
|
predicate.span,
|
|
)
|
|
} else {
|
|
continue;
|
|
}
|
|
},
|
|
_ => { continue; }
|
|
}
|
|
}
|
|
_ => continue,
|
|
};
|
|
if relevant_lifetimes.is_empty() {
|
|
continue;
|
|
}
|
|
|
|
let bound_spans = self.collect_outlives_bound_spans(
|
|
cx.tcx, bounds, &relevant_lifetimes, infer_static,
|
|
);
|
|
bound_count += bound_spans.len();
|
|
|
|
let drop_predicate = bound_spans.len() == bounds.len();
|
|
if drop_predicate {
|
|
dropped_predicate_count += 1;
|
|
}
|
|
|
|
// If all the bounds on a predicate were inferable and there are
|
|
// further predicates, we want to eat the trailing comma.
|
|
if drop_predicate && i + 1 < num_predicates {
|
|
let next_predicate_span = hir_generics.where_clause.predicates[i + 1].span();
|
|
where_lint_spans.push(
|
|
span.to(next_predicate_span.shrink_to_lo())
|
|
);
|
|
} else {
|
|
where_lint_spans.extend(
|
|
self.consolidate_outlives_bound_spans(
|
|
span.shrink_to_lo(),
|
|
bounds,
|
|
bound_spans
|
|
)
|
|
);
|
|
}
|
|
}
|
|
|
|
// If all predicates are inferable, drop the entire clause
|
|
// (including the `where`)
|
|
if num_predicates > 0 && dropped_predicate_count == num_predicates {
|
|
let where_span = hir_generics.where_clause.span()
|
|
.expect("span of (nonempty) where clause should exist");
|
|
// Extend the where clause back to the closing `>` of the
|
|
// generics, except for tuple struct, which have the `where`
|
|
// after the fields of the struct.
|
|
let full_where_span = if let hir::ItemKind::Struct(hir::VariantData::Tuple(..), _)
|
|
= item.kind
|
|
{
|
|
where_span
|
|
} else {
|
|
hir_generics.span.shrink_to_hi().to(where_span)
|
|
};
|
|
lint_spans.push(
|
|
full_where_span
|
|
);
|
|
} else {
|
|
lint_spans.extend(where_lint_spans);
|
|
}
|
|
|
|
if !lint_spans.is_empty() {
|
|
let mut err = cx.struct_span_lint(
|
|
EXPLICIT_OUTLIVES_REQUIREMENTS,
|
|
lint_spans.clone(),
|
|
"outlives requirements can be inferred"
|
|
);
|
|
err.multipart_suggestion(
|
|
if bound_count == 1 {
|
|
"remove this bound"
|
|
} else {
|
|
"remove these bounds"
|
|
},
|
|
lint_spans.into_iter().map(|span| (span, "".to_owned())).collect::<Vec<_>>(),
|
|
Applicability::MachineApplicable
|
|
);
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub INCOMPLETE_FEATURES,
|
|
Warn,
|
|
"incomplete features that may function improperly in some or all cases"
|
|
}
|
|
|
|
declare_lint_pass!(
|
|
/// Check for used feature gates in `INCOMPLETE_FEATURES` in `feature_gate.rs`.
|
|
IncompleteFeatures => [INCOMPLETE_FEATURES]
|
|
);
|
|
|
|
impl EarlyLintPass for IncompleteFeatures {
|
|
fn check_crate(&mut self, cx: &EarlyContext<'_>, _: &ast::Crate) {
|
|
let features = cx.sess.features_untracked();
|
|
features.declared_lang_features
|
|
.iter().map(|(name, span, _)| (name, span))
|
|
.chain(features.declared_lib_features.iter().map(|(name, span)| (name, span)))
|
|
.filter(|(name, _)| rustc_feature::INCOMPLETE_FEATURES.iter().any(|f| name == &f))
|
|
.for_each(|(name, &span)| {
|
|
cx.struct_span_lint(
|
|
INCOMPLETE_FEATURES,
|
|
span,
|
|
&format!(
|
|
"the feature `{}` is incomplete and may cause the compiler to crash",
|
|
name,
|
|
)
|
|
)
|
|
.emit();
|
|
});
|
|
}
|
|
}
|
|
|
|
declare_lint! {
|
|
pub INVALID_VALUE,
|
|
Warn,
|
|
"an invalid value is being created (such as a NULL reference)"
|
|
}
|
|
|
|
declare_lint_pass!(InvalidValue => [INVALID_VALUE]);
|
|
|
|
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidValue {
|
|
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &hir::Expr) {
|
|
|
|
#[derive(Debug, Copy, Clone, PartialEq)]
|
|
enum InitKind { Zeroed, Uninit };
|
|
|
|
/// Information about why a type cannot be initialized this way.
|
|
/// Contains an error message and optionally a span to point at.
|
|
type InitError = (String, Option<Span>);
|
|
|
|
/// Test if this constant is all-0.
|
|
fn is_zero(expr: &hir::Expr) -> bool {
|
|
use hir::ExprKind::*;
|
|
use syntax::ast::LitKind::*;
|
|
match &expr.kind {
|
|
Lit(lit) =>
|
|
if let Int(i, _) = lit.node {
|
|
i == 0
|
|
} else {
|
|
false
|
|
},
|
|
Tup(tup) =>
|
|
tup.iter().all(is_zero),
|
|
_ =>
|
|
false
|
|
}
|
|
}
|
|
|
|
/// Determine if this expression is a "dangerous initialization".
|
|
fn is_dangerous_init(cx: &LateContext<'_, '_>, expr: &hir::Expr) -> Option<InitKind> {
|
|
// `transmute` is inside an anonymous module (the `extern` block?);
|
|
// `Invalid` represents the empty string and matches that.
|
|
// FIXME(#66075): use diagnostic items. Somehow, that does not seem to work
|
|
// on intrinsics right now.
|
|
const TRANSMUTE_PATH: &[Symbol] =
|
|
&[sym::core, sym::intrinsics, kw::Invalid, sym::transmute];
|
|
|
|
if let hir::ExprKind::Call(ref path_expr, ref args) = expr.kind {
|
|
// Find calls to `mem::{uninitialized,zeroed}` methods.
|
|
if let hir::ExprKind::Path(ref qpath) = path_expr.kind {
|
|
let def_id = cx.tables.qpath_res(qpath, path_expr.hir_id).opt_def_id()?;
|
|
|
|
if cx.tcx.is_diagnostic_item(sym::mem_zeroed, def_id) {
|
|
return Some(InitKind::Zeroed);
|
|
} else if cx.tcx.is_diagnostic_item(sym::mem_uninitialized, def_id) {
|
|
return Some(InitKind::Uninit);
|
|
} else if cx.match_def_path(def_id, TRANSMUTE_PATH) {
|
|
if is_zero(&args[0]) {
|
|
return Some(InitKind::Zeroed);
|
|
}
|
|
}
|
|
}
|
|
} else if let hir::ExprKind::MethodCall(_, _, ref args) = expr.kind {
|
|
// Find problematic calls to `MaybeUninit::assume_init`.
|
|
let def_id = cx.tables.type_dependent_def_id(expr.hir_id)?;
|
|
if cx.tcx.is_diagnostic_item(sym::assume_init, def_id) {
|
|
// This is a call to *some* method named `assume_init`.
|
|
// See if the `self` parameter is one of the dangerous constructors.
|
|
if let hir::ExprKind::Call(ref path_expr, _) = args[0].kind {
|
|
if let hir::ExprKind::Path(ref qpath) = path_expr.kind {
|
|
let def_id = cx.tables.qpath_res(qpath, path_expr.hir_id).opt_def_id()?;
|
|
|
|
if cx.tcx.is_diagnostic_item(sym::maybe_uninit_zeroed, def_id) {
|
|
return Some(InitKind::Zeroed);
|
|
} else if cx.tcx.is_diagnostic_item(sym::maybe_uninit_uninit, def_id) {
|
|
return Some(InitKind::Uninit);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
/// Return `Some` only if we are sure this type does *not*
|
|
/// allow zero initialization.
|
|
fn ty_find_init_error<'tcx>(
|
|
tcx: TyCtxt<'tcx>,
|
|
ty: Ty<'tcx>,
|
|
init: InitKind,
|
|
) -> Option<InitError> {
|
|
use rustc::ty::TyKind::*;
|
|
match ty.kind {
|
|
// Primitive types that don't like 0 as a value.
|
|
Ref(..) => Some((format!("References must be non-null"), None)),
|
|
Adt(..) if ty.is_box() => Some((format!("`Box` must be non-null"), None)),
|
|
FnPtr(..) => Some((format!("Function pointers must be non-null"), None)),
|
|
Never => Some((format!("The never type (`!`) has no valid value"), None)),
|
|
RawPtr(tm) if matches!(tm.ty.kind, Dynamic(..)) => // raw ptr to dyn Trait
|
|
Some((format!("The vtable of a wide raw pointer must be non-null"), None)),
|
|
// Primitive types with other constraints.
|
|
Bool if init == InitKind::Uninit =>
|
|
Some((format!("Booleans must be `true` or `false`"), None)),
|
|
Char if init == InitKind::Uninit =>
|
|
Some((format!("Characters must be a valid unicode codepoint"), None)),
|
|
// Recurse and checks for some compound types.
|
|
Adt(adt_def, substs) if !adt_def.is_union() => {
|
|
// First check f this ADT has a layout attribute (like `NonNull` and friends).
|
|
use std::ops::Bound;
|
|
match tcx.layout_scalar_valid_range(adt_def.did) {
|
|
// We exploit here that `layout_scalar_valid_range` will never
|
|
// return `Bound::Excluded`. (And we have tests checking that we
|
|
// handle the attribute correctly.)
|
|
(Bound::Included(lo), _) if lo > 0 =>
|
|
return Some((format!("{} must be non-null", ty), None)),
|
|
(Bound::Included(_), _) | (_, Bound::Included(_))
|
|
if init == InitKind::Uninit =>
|
|
return Some((
|
|
format!("{} must be initialized inside its custom valid range", ty),
|
|
None,
|
|
)),
|
|
_ => {}
|
|
}
|
|
// Now, recurse.
|
|
match adt_def.variants.len() {
|
|
0 => Some((format!("0-variant enums have no valid value"), None)),
|
|
1 => {
|
|
// Struct, or enum with exactly one variant.
|
|
// Proceed recursively, check all fields.
|
|
let variant = &adt_def.variants[VariantIdx::from_u32(0)];
|
|
variant.fields.iter().find_map(|field| {
|
|
ty_find_init_error(
|
|
tcx,
|
|
field.ty(tcx, substs),
|
|
init,
|
|
).map(|(mut msg, span)| if span.is_none() {
|
|
// Point to this field, should be helpful for figuring
|
|
// out where the source of the error is.
|
|
let span = tcx.def_span(field.did);
|
|
write!(&mut msg, " (in this {} field)", adt_def.descr())
|
|
.unwrap();
|
|
(msg, Some(span))
|
|
} else {
|
|
// Just forward.
|
|
(msg, span)
|
|
})
|
|
})
|
|
}
|
|
// Multi-variant enums are tricky: if all but one variant are
|
|
// uninhabited, we might actually do layout like for a single-variant
|
|
// enum, and then even leaving them uninitialized could be okay.
|
|
_ => None, // Conservative fallback for multi-variant enum.
|
|
}
|
|
}
|
|
Tuple(..) => {
|
|
// Proceed recursively, check all fields.
|
|
ty.tuple_fields().find_map(|field| ty_find_init_error(tcx, field, init))
|
|
}
|
|
// Conservative fallback.
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
if let Some(init) = is_dangerous_init(cx, expr) {
|
|
// This conjures an instance of a type out of nothing,
|
|
// using zeroed or uninitialized memory.
|
|
// We are extremely conservative with what we warn about.
|
|
let conjured_ty = cx.tables.expr_ty(expr);
|
|
if let Some((msg, span)) = ty_find_init_error(cx.tcx, conjured_ty, init) {
|
|
let mut err = cx.struct_span_lint(
|
|
INVALID_VALUE,
|
|
expr.span,
|
|
&format!(
|
|
"the type `{}` does not permit {}",
|
|
conjured_ty,
|
|
match init {
|
|
InitKind::Zeroed => "zero-initialization",
|
|
InitKind::Uninit => "being left uninitialized",
|
|
},
|
|
),
|
|
);
|
|
err.span_label(expr.span,
|
|
"this code causes undefined behavior when executed");
|
|
err.span_label(expr.span, "help: use `MaybeUninit<T>` instead, \
|
|
and only call `assume_init` after initialization is done");
|
|
if let Some(span) = span {
|
|
err.span_note(span, &msg);
|
|
} else {
|
|
err.note(&msg);
|
|
}
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
}
|