use crate::consts::{constant_simple, Constant};
-use crate::utils::{match_def_path, paths, span_lint};
+use crate::utils::{match_def_path, match_trait_method, paths, span_lint};
+use if_chain::if_chain;
use rustc_hir::{Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
/// ```ignore
/// min(0, max(100, x))
/// ```
+ /// or
+ /// ```ignore
+ /// x.max(100).min(0)
+ /// ```
/// It will always be equal to `0`. Probably the author meant to clamp the value
/// between 0 and 100, but has erroneously swapped `min` and `max`.
pub MIN_MAX,
}
fn min_max<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<(MinMax, Constant, &'a Expr<'a>)> {
- if let ExprKind::Call(ref path, ref args) = expr.kind {
- if let ExprKind::Path(ref qpath) = path.kind {
- cx.typeck_results()
- .qpath_res(qpath, path.hir_id)
- .opt_def_id()
- .and_then(|def_id| {
- if match_def_path(cx, def_id, &paths::CMP_MIN) {
- fetch_const(cx, args, MinMax::Min)
- } else if match_def_path(cx, def_id, &paths::CMP_MAX) {
+ match expr.kind {
+ ExprKind::Call(ref path, ref args) => {
+ if let ExprKind::Path(ref qpath) = path.kind {
+ cx.typeck_results()
+ .qpath_res(qpath, path.hir_id)
+ .opt_def_id()
+ .and_then(|def_id| {
+ if match_def_path(cx, def_id, &paths::CMP_MIN) {
+ fetch_const(cx, args, MinMax::Min)
+ } else if match_def_path(cx, def_id, &paths::CMP_MAX) {
+ fetch_const(cx, args, MinMax::Max)
+ } else {
+ None
+ }
+ })
+ } else {
+ None
+ }
+ },
+ ExprKind::MethodCall(ref path, _, ref args, _) => {
+ if_chain! {
+ if let [obj, _] = args;
+ if cx.typeck_results().expr_ty(obj).is_floating_point() || match_trait_method(cx, expr, &paths::ORD);
+ then {
+ if path.ident.name == sym!(max) {
fetch_const(cx, args, MinMax::Max)
+ } else if path.ident.name == sym!(min) {
+ fetch_const(cx, args, MinMax::Min)
} else {
None
}
- })
- } else {
- None
- }
- } else {
- None
+ } else {
+ None
+ }
+ }
+ },
+ _ => None,
}
}