//! calculate cognitive complexity and warn about overly complex functions
-use rustc::hir::intravisit::{walk_expr, FnKind, NestedVisitorMap, Visitor};
-use rustc::hir::*;
-use rustc::impl_lint_pass;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintContext, LintPass};
-use rustc_session::declare_tool_lint;
+use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::source::snippet_opt;
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::LimitStack;
+use rustc_ast::ast::Attribute;
+use rustc_hir::intravisit::{walk_expr, FnKind, NestedVisitorMap, Visitor};
+use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
use rustc_span::source_map::Span;
-use rustc_span::BytePos;
-use syntax::ast::Attribute;
-
-use crate::utils::{match_type, paths, snippet_opt, span_help_and_lint, LimitStack};
+use rustc_span::{sym, BytePos};
declare_clippy_lint! {
- /// **What it does:** Checks for methods with high cognitive complexity.
+ /// ### What it does
+ /// Checks for methods with high cognitive complexity.
///
- /// **Why is this bad?** Methods of high cognitive complexity tend to be hard to
+ /// ### Why is this bad?
+ /// Methods of high cognitive complexity tend to be hard to
/// both read and maintain. Also LLVM will tend to optimize small methods better.
///
- /// **Known problems:** Sometimes it's hard to find a way to reduce the
+ /// ### Known problems
+ /// Sometimes it's hard to find a way to reduce the
/// complexity.
///
- /// **Example:** No. You'll see it when you get the warning.
+ /// ### Example
+ /// No. You'll see it when you get the warning.
pub COGNITIVE_COMPLEXITY,
- complexity,
+ nursery,
"functions that should be split up into multiple functions"
}
impl CognitiveComplexity {
#[allow(clippy::cast_possible_truncation)]
- fn check<'a, 'tcx>(
+ fn check<'tcx>(
&mut self,
- cx: &'a LateContext<'a, 'tcx>,
+ cx: &LateContext<'tcx>,
kind: FnKind<'tcx>,
decl: &'tcx FnDecl<'_>,
body: &'tcx Body<'_>,
let expr = &body.value;
- let mut helper = CCHelper { cc: 1, returns: 0 };
+ let mut helper = CcHelper { cc: 1, returns: 0 };
helper.visit_expr(expr);
- let CCHelper { cc, returns } = helper;
- let ret_ty = cx.tables.node_type(expr.hir_id);
- let ret_adjust = if match_type(cx, ret_ty, &paths::RESULT) {
+ let CcHelper { cc, returns } = helper;
+ let ret_ty = cx.typeck_results().node_type(expr.hir_id);
+ let ret_adjust = if is_type_diagnostic_item(cx, ret_ty, sym::Result) {
returns
} else {
#[allow(clippy::integer_division)]
if rust_cc > self.limit.limit() {
let fn_span = match kind {
- FnKind::ItemFn(ident, _, _, _, _) | FnKind::Method(ident, _, _, _) => ident.span,
- FnKind::Closure(_) => {
+ FnKind::ItemFn(ident, _, _, _) | FnKind::Method(ident, _, _) => ident.span,
+ FnKind::Closure => {
let header_span = body_span.with_hi(decl.output.span().lo());
let pos = snippet_opt(cx, header_span).and_then(|snip| {
let low_offset = snip.find('|')?;
});
if let Some((low, high)) = pos {
- Span::new(low, high, header_span.ctxt())
+ Span::new(low, high, header_span.ctxt(), header_span.parent())
} else {
return;
}
},
};
- span_help_and_lint(
+ span_lint_and_help(
cx,
COGNITIVE_COMPLEXITY,
fn_span,
rust_cc,
self.limit.limit()
),
+ None,
"you could split it up into multiple smaller functions",
);
}
}
}
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CognitiveComplexity {
+impl<'tcx> LateLintPass<'tcx> for CognitiveComplexity {
fn check_fn(
&mut self,
- cx: &LateContext<'a, 'tcx>,
+ cx: &LateContext<'tcx>,
kind: FnKind<'tcx>,
decl: &'tcx FnDecl<'_>,
body: &'tcx Body<'_>,
hir_id: HirId,
) {
let def_id = cx.tcx.hir().local_def_id(hir_id);
- if !cx.tcx.has_attr(def_id, sym!(test)) {
+ if !cx.tcx.has_attr(def_id.to_def_id(), sym::test) {
self.check(cx, kind, decl, body, span);
}
}
- fn enter_lint_attrs(&mut self, cx: &LateContext<'a, 'tcx>, attrs: &'tcx [Attribute]) {
+ fn enter_lint_attrs(&mut self, cx: &LateContext<'tcx>, attrs: &'tcx [Attribute]) {
self.limit.push_attrs(cx.sess(), attrs, "cognitive_complexity");
}
- fn exit_lint_attrs(&mut self, cx: &LateContext<'a, 'tcx>, attrs: &'tcx [Attribute]) {
+ fn exit_lint_attrs(&mut self, cx: &LateContext<'tcx>, attrs: &'tcx [Attribute]) {
self.limit.pop_attrs(cx.sess(), attrs, "cognitive_complexity");
}
}
-struct CCHelper {
+struct CcHelper {
cc: u64,
returns: u64,
}
-impl<'tcx> Visitor<'tcx> for CCHelper {
+impl<'tcx> Visitor<'tcx> for CcHelper {
+ type Map = Map<'tcx>;
+
fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
walk_expr(self, e);
match e.kind {
- ExprKind::Match(_, ref arms, _) => {
+ ExprKind::If(_, _, _) => {
+ self.cc += 1;
+ },
+ ExprKind::Match(_, arms, _) => {
if arms.len() > 1 {
self.cc += 1;
}
_ => {},
}
}
- fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::None
}
}
projects / rust.git / blobdiff