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| 1 | +use crate::utils::{is_direct_expn_of, span_lint}; |
| 2 | +use if_chain::if_chain; |
| 3 | +use matches::matches; |
| 4 | +use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor}; |
| 5 | +use rustc::hir::{Expr, ExprKind, Mutability, StmtKind, UnOp}; |
| 6 | +use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass}; |
| 7 | +use rustc::{declare_lint_pass, declare_tool_lint, ty}; |
| 8 | +use syntax_pos::Span; |
| 9 | + |
| 10 | +declare_clippy_lint! { |
| 11 | + /// **What it does:** Checks for function/method calls with a mutable |
| 12 | + /// parameter in `debug_assert!`, `debug_assert_eq!` and `debug_assert_ne!` macros. |
| 13 | + /// |
| 14 | + /// **Why is this bad?** In release builds `debug_assert!` macros are optimized out by the |
| 15 | + /// compiler. |
| 16 | + /// Therefore mutating something in a `debug_assert!` macro results in different behaviour |
| 17 | + /// between a release and debug build. |
| 18 | + /// |
| 19 | + /// **Known problems:** None |
| 20 | + /// |
| 21 | + /// **Example:** |
| 22 | + /// ```rust,ignore |
| 23 | + /// debug_assert_eq!(vec![3].pop(), Some(3)); |
| 24 | + /// // or |
| 25 | + /// fn take_a_mut_parameter(_: &mut u32) -> bool { unimplemented!() } |
| 26 | + /// debug_assert!(take_a_mut_parameter(&mut 5)); |
| 27 | + /// ``` |
| 28 | + pub DEBUG_ASSERT_WITH_MUT_CALL, |
| 29 | + correctness, |
| 30 | + "mutable arguments in `debug_assert{,_ne,_eq}!`" |
| 31 | +} |
| 32 | + |
| 33 | +declare_lint_pass!(DebugAssertWithMutCall => [DEBUG_ASSERT_WITH_MUT_CALL]); |
| 34 | + |
| 35 | +const DEBUG_MACRO_NAMES: [&str; 3] = ["debug_assert", "debug_assert_eq", "debug_assert_ne"]; |
| 36 | + |
| 37 | +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DebugAssertWithMutCall { |
| 38 | + fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) { |
| 39 | + for dmn in &DEBUG_MACRO_NAMES { |
| 40 | + if is_direct_expn_of(e.span, dmn).is_some() { |
| 41 | + if let Some(span) = extract_call(cx, e) { |
| 42 | + span_lint( |
| 43 | + cx, |
| 44 | + DEBUG_ASSERT_WITH_MUT_CALL, |
| 45 | + span, |
| 46 | + &format!("do not call a function with mutable arguments inside of `{}!`", dmn), |
| 47 | + ); |
| 48 | + } |
| 49 | + } |
| 50 | + } |
| 51 | + } |
| 52 | +} |
| 53 | + |
| 54 | +//HACK(hellow554): remove this when #4694 is implemented |
| 55 | +#[allow(clippy::cognitive_complexity)] |
| 56 | +fn extract_call<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, e: &'tcx Expr) -> Option<Span> { |
| 57 | + if_chain! { |
| 58 | + if let ExprKind::Block(ref block, _) = e.kind; |
| 59 | + if block.stmts.len() == 1; |
| 60 | + if let StmtKind::Semi(ref matchexpr) = block.stmts[0].kind; |
| 61 | + then { |
| 62 | + if_chain! { |
| 63 | + if let ExprKind::Match(ref ifclause, _, _) = matchexpr.kind; |
| 64 | + if let ExprKind::DropTemps(ref droptmp) = ifclause.kind; |
| 65 | + if let ExprKind::Unary(UnOp::UnNot, ref condition) = droptmp.kind; |
| 66 | + then { |
| 67 | + // debug_assert |
| 68 | + let mut visitor = MutArgVisitor::new(cx); |
| 69 | + visitor.visit_expr(condition); |
| 70 | + return visitor.expr_span(); |
| 71 | + } else { |
| 72 | + // debug_assert_{eq,ne} |
| 73 | + if_chain! { |
| 74 | + if let ExprKind::Block(ref matchblock, _) = matchexpr.kind; |
| 75 | + if let Some(ref matchheader) = matchblock.expr; |
| 76 | + if let ExprKind::Match(ref headerexpr, _, _) = matchheader.kind; |
| 77 | + if let ExprKind::Tup(ref conditions) = headerexpr.kind; |
| 78 | + if conditions.len() == 2; |
| 79 | + then { |
| 80 | + if let ExprKind::AddrOf(_, ref lhs) = conditions[0].kind { |
| 81 | + let mut visitor = MutArgVisitor::new(cx); |
| 82 | + visitor.visit_expr(lhs); |
| 83 | + if let Some(span) = visitor.expr_span() { |
| 84 | + return Some(span); |
| 85 | + } |
| 86 | + } |
| 87 | + if let ExprKind::AddrOf(_, ref rhs) = conditions[1].kind { |
| 88 | + let mut visitor = MutArgVisitor::new(cx); |
| 89 | + visitor.visit_expr(rhs); |
| 90 | + if let Some(span) = visitor.expr_span() { |
| 91 | + return Some(span); |
| 92 | + } |
| 93 | + } |
| 94 | + } |
| 95 | + } |
| 96 | + } |
| 97 | + } |
| 98 | + } |
| 99 | + } |
| 100 | + |
| 101 | + None |
| 102 | +} |
| 103 | + |
| 104 | +struct MutArgVisitor<'a, 'tcx> { |
| 105 | + cx: &'a LateContext<'a, 'tcx>, |
| 106 | + expr_span: Option<Span>, |
| 107 | + found: bool, |
| 108 | +} |
| 109 | + |
| 110 | +impl<'a, 'tcx> MutArgVisitor<'a, 'tcx> { |
| 111 | + fn new(cx: &'a LateContext<'a, 'tcx>) -> Self { |
| 112 | + Self { |
| 113 | + cx, |
| 114 | + expr_span: None, |
| 115 | + found: false, |
| 116 | + } |
| 117 | + } |
| 118 | + |
| 119 | + fn expr_span(&self) -> Option<Span> { |
| 120 | + if self.found { |
| 121 | + self.expr_span |
| 122 | + } else { |
| 123 | + None |
| 124 | + } |
| 125 | + } |
| 126 | +} |
| 127 | + |
| 128 | +impl<'a, 'tcx> Visitor<'tcx> for MutArgVisitor<'a, 'tcx> { |
| 129 | + fn visit_expr(&mut self, expr: &'tcx Expr) { |
| 130 | + match expr.kind { |
| 131 | + ExprKind::AddrOf(Mutability::MutMutable, _) => { |
| 132 | + self.found = true; |
| 133 | + return; |
| 134 | + }, |
| 135 | + ExprKind::Path(_) => { |
| 136 | + if let Some(adj) = self.cx.tables.adjustments().get(expr.hir_id) { |
| 137 | + if adj |
| 138 | + .iter() |
| 139 | + .any(|a| matches!(a.target.kind, ty::Ref(_, _, Mutability::MutMutable))) |
| 140 | + { |
| 141 | + self.found = true; |
| 142 | + return; |
| 143 | + } |
| 144 | + } |
| 145 | + }, |
| 146 | + _ if !self.found => self.expr_span = Some(expr.span), |
| 147 | + _ => return, |
| 148 | + } |
| 149 | + walk_expr(self, expr) |
| 150 | + } |
| 151 | + |
| 152 | + fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| 153 | + NestedVisitorMap::OnlyBodies(&self.cx.tcx.hir()) |
| 154 | + } |
| 155 | +} |
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