-use crate::utils::{higher::if_block, match_type, paths, span_lint_and_then, usage::is_potentially_mutated};
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{differing_macro_contexts, usage::is_potentially_mutated};
use if_chain::if_chain;
-use rustc::hir::map::Map;
-use rustc_hir::intravisit::*;
-use rustc_hir::*;
+use rustc_hir::intravisit::{walk_expr, walk_fn, FnKind, NestedVisitorMap, Visitor};
+use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, Path, QPath, UnOp};
use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::Ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Span;
+use rustc_span::sym;
declare_clippy_lint! {
/// **What it does:** Checks for calls of `unwrap[_err]()` that cannot fail.
/// Visitor that keeps track of which variables are unwrappable.
struct UnwrappableVariablesVisitor<'a, 'tcx> {
unwrappables: Vec<UnwrapInfo<'tcx>>,
- cx: &'a LateContext<'a, 'tcx>,
+ cx: &'a LateContext<'tcx>,
}
/// Contains information about whether a variable can be unwrapped.
#[derive(Copy, Clone, Debug)]
ident: &'tcx Path<'tcx>,
/// The check, like `x.is_ok()`
check: &'tcx Expr<'tcx>,
+ /// The branch where the check takes place, like `if x.is_ok() { .. }`
+ branch: &'tcx Expr<'tcx>,
/// Whether `is_some()` or `is_ok()` was called (as opposed to `is_err()` or `is_none()`).
safe_to_unwrap: bool,
}
/// Collects the information about unwrappable variables from an if condition
/// The `invert` argument tells us whether the condition is negated.
-fn collect_unwrap_info<'a, 'tcx>(
- cx: &'a LateContext<'a, 'tcx>,
+fn collect_unwrap_info<'tcx>(
+ cx: &LateContext<'tcx>,
expr: &'tcx Expr<'_>,
+ branch: &'tcx Expr<'_>,
invert: bool,
) -> Vec<UnwrapInfo<'tcx>> {
+ fn is_relevant_option_call(cx: &LateContext<'_>, ty: Ty<'_>, method_name: &str) -> bool {
+ is_type_diagnostic_item(cx, ty, sym::option_type) && ["is_some", "is_none"].contains(&method_name)
+ }
+
+ fn is_relevant_result_call(cx: &LateContext<'_>, ty: Ty<'_>, method_name: &str) -> bool {
+ is_type_diagnostic_item(cx, ty, sym::result_type) && ["is_ok", "is_err"].contains(&method_name)
+ }
+
if let ExprKind::Binary(op, left, right) = &expr.kind {
match (invert, op.node) {
- (false, BinOpKind::And) | (false, BinOpKind::BitAnd) | (true, BinOpKind::Or) | (true, BinOpKind::BitOr) => {
- let mut unwrap_info = collect_unwrap_info(cx, left, invert);
- unwrap_info.append(&mut collect_unwrap_info(cx, right, invert));
+ (false, BinOpKind::And | BinOpKind::BitAnd) | (true, BinOpKind::Or | BinOpKind::BitOr) => {
+ let mut unwrap_info = collect_unwrap_info(cx, left, branch, invert);
+ unwrap_info.append(&mut collect_unwrap_info(cx, right, branch, invert));
return unwrap_info;
},
_ => (),
}
- } else if let ExprKind::Unary(UnOp::UnNot, expr) = &expr.kind {
- return collect_unwrap_info(cx, expr, !invert);
+ } else if let ExprKind::Unary(UnOp::Not, expr) = &expr.kind {
+ return collect_unwrap_info(cx, expr, branch, !invert);
} else {
if_chain! {
- if let ExprKind::MethodCall(method_name, _, args) = &expr.kind;
+ if let ExprKind::MethodCall(method_name, _, args, _) = &expr.kind;
if let ExprKind::Path(QPath::Resolved(None, path)) = &args[0].kind;
- let ty = cx.tables.expr_ty(&args[0]);
- if match_type(cx, ty, &paths::OPTION) || match_type(cx, ty, &paths::RESULT);
+ let ty = cx.typeck_results().expr_ty(&args[0]);
let name = method_name.ident.as_str();
- if ["is_some", "is_none", "is_ok", "is_err"].contains(&&*name);
+ if is_relevant_option_call(cx, ty, &name) || is_relevant_result_call(cx, ty, &name);
then {
assert!(args.len() == 1);
let unwrappable = match name.as_ref() {
_ => unreachable!(),
};
let safe_to_unwrap = unwrappable != invert;
- return vec![UnwrapInfo { ident: path, check: expr, safe_to_unwrap }];
+ return vec![UnwrapInfo { ident: path, check: expr, branch, safe_to_unwrap }];
}
}
}
impl<'a, 'tcx> UnwrappableVariablesVisitor<'a, 'tcx> {
fn visit_branch(&mut self, cond: &'tcx Expr<'_>, branch: &'tcx Expr<'_>, else_branch: bool) {
let prev_len = self.unwrappables.len();
- for unwrap_info in collect_unwrap_info(self.cx, cond, else_branch) {
+ for unwrap_info in collect_unwrap_info(self.cx, cond, branch, else_branch) {
if is_potentially_mutated(unwrap_info.ident, cond, self.cx)
|| is_potentially_mutated(unwrap_info.ident, branch, self.cx)
{
type Map = Map<'tcx>;
fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
- if let Some((cond, then, els)) = if_block(&expr) {
+ // Shouldn't lint when `expr` is in macro.
+ if in_external_macro(self.cx.tcx.sess, expr.span) {
+ return;
+ }
+ if let ExprKind::If(cond, then, els) = &expr.kind {
walk_expr(self, cond);
self.visit_branch(cond, then, false);
if let Some(els) = els {
} else {
// find `unwrap[_err]()` calls:
if_chain! {
- if let ExprKind::MethodCall(ref method_name, _, ref args) = expr.kind;
- if let ExprKind::Path(QPath::Resolved(None, ref path)) = args[0].kind;
- if [sym!(unwrap), sym!(unwrap_err)].contains(&method_name.ident.name);
- let call_to_unwrap = method_name.ident.name == sym!(unwrap);
+ if let ExprKind::MethodCall(method_name, _, args, _) = expr.kind;
+ if let ExprKind::Path(QPath::Resolved(None, path)) = args[0].kind;
+ if [sym::unwrap, sym!(unwrap_err)].contains(&method_name.ident.name);
+ let call_to_unwrap = method_name.ident.name == sym::unwrap;
if let Some(unwrappable) = self.unwrappables.iter()
.find(|u| u.ident.res == path.res);
+ // Span contexts should not differ with the conditional branch
+ if !differing_macro_contexts(unwrappable.branch.span, expr.span);
+ if !differing_macro_contexts(unwrappable.branch.span, unwrappable.check.span);
then {
if call_to_unwrap == unwrappable.safe_to_unwrap {
span_lint_and_then(
self.cx,
UNNECESSARY_UNWRAP,
expr.span,
- &format!("You checked before that `{}()` cannot fail. \
- Instead of checking and unwrapping, it's better to use `if let` or `match`.",
+ &format!("you checked before that `{}()` cannot fail, \
+ instead of checking and unwrapping, it's better to use `if let` or `match`",
method_name.ident.name),
- |db| { db.span_label(unwrappable.check.span, "the check is happening here"); },
+ |diag| { diag.span_label(unwrappable.check.span, "the check is happening here"); },
);
} else {
span_lint_and_then(
self.cx,
PANICKING_UNWRAP,
expr.span,
- &format!("This call to `{}()` will always panic.",
+ &format!("this call to `{}()` will always panic",
method_name.ident.name),
- |db| { db.span_label(unwrappable.check.span, "because of this check"); },
+ |diag| { diag.span_label(unwrappable.check.span, "because of this check"); },
);
}
}
}
}
- fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
- NestedVisitorMap::OnlyBodies(&self.cx.tcx.hir())
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+ NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
}
}
declare_lint_pass!(Unwrap => [PANICKING_UNWRAP, UNNECESSARY_UNWRAP]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Unwrap {
+impl<'tcx> LateLintPass<'tcx> for Unwrap {
fn check_fn(
&mut self,
- cx: &LateContext<'a, 'tcx>,
+ cx: &LateContext<'tcx>,
kind: FnKind<'tcx>,
decl: &'tcx FnDecl<'_>,
body: &'tcx Body<'_>,
projects / rust.git / blobdiff