-use crate::utils::{match_type, paths, span_lint_and_help};
-use rustc::hir::map::Map;
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::SpanlessEq;
+use if_chain::if_chain;
use rustc_hir::intravisit::{self as visit, NestedVisitorMap, Visitor};
-use rustc_hir::{Arm, Expr, ExprKind, MatchSource, StmtKind};
+use rustc_hir::{Expr, ExprKind, MatchSource};
use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
declare_lint_pass!(IfLetMutex => [IF_LET_MUTEX]);
-impl LateLintPass<'_, '_> for IfLetMutex {
- fn check_expr(&mut self, cx: &LateContext<'_, '_>, ex: &'_ Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for IfLetMutex {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, ex: &'tcx Expr<'tcx>) {
let mut arm_visit = ArmVisitor {
- arm_mutex: false,
- arm_lock: false,
+ mutex_lock_called: false,
+ found_mutex: None,
cx,
};
let mut op_visit = OppVisitor {
- op_mutex: false,
- op_lock: false,
+ mutex_lock_called: false,
+ found_mutex: None,
cx,
};
if let ExprKind::Match(
- ref op,
- ref arms,
+ op,
+ arms,
MatchSource::IfLetDesugar {
contains_else_clause: true,
},
) = ex.kind
{
op_visit.visit_expr(op);
- if op_visit.op_mutex && op_visit.op_lock {
- for arm in *arms {
+ if op_visit.mutex_lock_called {
+ for arm in arms {
arm_visit.visit_arm(arm);
}
- if arm_visit.arm_mutex && arm_visit.arm_lock {
+ if arm_visit.mutex_lock_called && arm_visit.same_mutex(cx, op_visit.found_mutex.unwrap()) {
span_lint_and_help(
cx,
IF_LET_MUTEX,
ex.span,
"calling `Mutex::lock` inside the scope of another `Mutex::lock` causes a deadlock",
+ None,
"move the lock call outside of the `if let ...` expression",
);
}
}
/// Checks if `Mutex::lock` is called in the `if let _ = expr.
-pub struct OppVisitor<'tcx, 'l> {
- pub op_mutex: bool,
- pub op_lock: bool,
- pub cx: &'tcx LateContext<'tcx, 'l>,
+pub struct OppVisitor<'a, 'tcx> {
+ mutex_lock_called: bool,
+ found_mutex: Option<&'tcx Expr<'tcx>>,
+ cx: &'a LateContext<'tcx>,
}
-impl<'tcx, 'l> Visitor<'tcx> for OppVisitor<'tcx, 'l> {
+impl<'tcx> Visitor<'tcx> for OppVisitor<'_, 'tcx> {
type Map = Map<'tcx>;
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
- if let ExprKind::MethodCall(path, _span, args) = &expr.kind {
- if path.ident.to_string() == "lock" {
- self.op_lock = true;
- }
- let ty = self.cx.tables.expr_ty(&args[0]);
- if match_type(self.cx, ty, &paths::MUTEX) {
- self.op_mutex = true;
- }
+ if let Some(mutex) = is_mutex_lock_call(self.cx, expr) {
+ self.found_mutex = Some(mutex);
+ self.mutex_lock_called = true;
+ return;
}
visit::walk_expr(self, expr);
}
}
/// Checks if `Mutex::lock` is called in any of the branches.
-pub struct ArmVisitor<'tcx, 'l> {
- pub arm_mutex: bool,
- pub arm_lock: bool,
- pub cx: &'tcx LateContext<'tcx, 'l>,
+pub struct ArmVisitor<'a, 'tcx> {
+ mutex_lock_called: bool,
+ found_mutex: Option<&'tcx Expr<'tcx>>,
+ cx: &'a LateContext<'tcx>,
}
-impl<'tcx, 'l> Visitor<'tcx> for ArmVisitor<'tcx, 'l> {
+impl<'tcx> Visitor<'tcx> for ArmVisitor<'_, 'tcx> {
type Map = Map<'tcx>;
- fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
- if let ExprKind::MethodCall(path, _span, args) = &expr.kind {
- if path.ident.to_string() == "lock" {
- self.arm_lock = true;
- }
- let ty = self.cx.tables.expr_ty(&args[0]);
- if match_type(self.cx, ty, &paths::MUTEX) {
- self.arm_mutex = true;
- }
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if let Some(mutex) = is_mutex_lock_call(self.cx, expr) {
+ self.found_mutex = Some(mutex);
+ self.mutex_lock_called = true;
+ return;
}
visit::walk_expr(self, expr);
}
- fn visit_arm(&mut self, arm: &'tcx Arm<'_>) {
- if let ExprKind::Block(ref block, _l) = arm.body.kind {
- for stmt in block.stmts {
- match stmt.kind {
- StmtKind::Local(loc) => {
- if let Some(expr) = loc.init {
- self.visit_expr(expr)
- }
- },
- StmtKind::Expr(expr) => self.visit_expr(expr),
- StmtKind::Semi(expr) => self.visit_expr(expr),
- // we don't care about `Item`
- _ => {},
- }
- }
- };
- visit::walk_arm(self, arm);
- }
-
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::None
}
}
+
+impl<'tcx, 'l> ArmVisitor<'tcx, 'l> {
+ fn same_mutex(&self, cx: &LateContext<'_>, op_mutex: &Expr<'_>) -> bool {
+ self.found_mutex
+ .map_or(false, |arm_mutex| SpanlessEq::new(cx).eq_expr(op_mutex, arm_mutex))
+ }
+}
+
+fn is_mutex_lock_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
+ if_chain! {
+ if let ExprKind::MethodCall(path, _span, args, _) = &expr.kind;
+ if path.ident.as_str() == "lock";
+ let ty = cx.typeck_results().expr_ty(&args[0]);
+ if is_type_diagnostic_item(cx, ty, sym!(mutex_type));
+ then {
+ Some(&args[0])
+ } else {
+ None
+ }
+ }
+}
projects / rust.git / blobdiff