Auto merge of #13540 - GnomedDev:create-dir-single-arg, r=y21

Check MethodCall/Call arg count earlier or at all
This gets rid of a bunch of possible panic spots, as well as bailing out earlier for optimisation reasons.
I started doing this because I saw that a significant amount of time was being spent in the `create_dir` restriction lint when running clippy with `perf`, but this also helps with robustness.
changelog: none

Author: bors

clippy_lints/src/box_default.rs

@@ -47,7 +47,7 @@ impl LateLintPass<'_> for BoxDefault {
 // And the call is that of a `Box` method
  && path_def_id(cx, ty).map_or(false, |id| Some(id) == cx.tcx.lang_items().owned_box())
 // And the single argument to the call is another function call
-// This is the `T::default()` of `Box::new(T::default())`
+// This is the `T::default()` (or default equivalent) of `Box::new(T::default())`
  && letExprKind::Call(arg_path, _) = arg.kind
 // And we are not in a foreign crate's macro
  && !in_external_macro(cx.sess(), expr.span)

clippy_lints/src/casts/cast_abs_to_unsigned.rs

@@ -19,7 +19,7 @@ pub(super) fn check(
 if msrv.meets(msrvs::UNSIGNED_ABS)
  && let ty::Int(from) = cast_from.kind()
  && let ty::Uint(to) = cast_to.kind()
- && letExprKind::MethodCall(method_path, receiver,..) = cast_expr.kind
+ && letExprKind::MethodCall(method_path, receiver,[], _) = cast_expr.kind
  && method_path.ident.name.as_str() == "abs"
 {
 let span = if from.bit_width() == to.bit_width(){

clippy_lints/src/casts/cast_ptr_alignment.rs

@@ -19,7 +19,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
  cx.typeck_results().expr_ty(expr),
 );
 lint_cast_ptr_alignment(cx, expr, cast_from, cast_to);
-}elseifletExprKind::MethodCall(method_path, self_arg,..) = &expr.kind{
+}elseifletExprKind::MethodCall(method_path, self_arg,[], _) = &expr.kind{
 if method_path.ident.name == sym!(cast)
  && letSome(generic_args) = method_path.args
  && let[GenericArg::Type(cast_to)] = generic_args.args

clippy_lints/src/create_dir.rs

@@ -34,7 +34,7 @@ declare_lint_pass!(CreateDir => [CREATE_DIR]);
 
 implLateLintPass<'_>forCreateDir{
 fncheck_expr(&mutself,cx:&LateContext<'_>,expr:&Expr<'_>){
-ifletExprKind::Call(func,[arg, ..]) = expr.kind
+ifletExprKind::Call(func,[arg]) = expr.kind
  && letExprKind::Path(ref path) = func.kind
  && letSome(def_id) = cx.qpath_res(path, func.hir_id).opt_def_id()
  && cx.tcx.is_diagnostic_item(sym::fs_create_dir, def_id)

clippy_lints/src/default.rs

@@ -83,7 +83,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
 if !expr.span.from_expansion()
 // Avoid cases already linted by `field_reassign_with_default`
  && !self.reassigned_linted.contains(&expr.span)
- && letExprKind::Call(path,..) = expr.kind
+ && letExprKind::Call(path,[]) = expr.kind
  && !in_automatically_derived(cx.tcx, expr.hir_id)
  && letExprKind::Path(ref qpath) = path.kind
  && letSome(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
@@ -253,7 +253,7 @@ impl<'tcx> LateLintPass<'tcx> for Default {
 
 /// Checks if the given expression is the `default` method belonging to the `Default` trait.
 fnis_expr_default<'tcx>(expr:&'tcxExpr<'tcx>,cx:&LateContext<'tcx>) -> bool{
-ifletExprKind::Call(fn_expr,_) = &expr.kind
+ifletExprKind::Call(fn_expr,[]) = &expr.kind
  && letExprKind::Path(qpath) = &fn_expr.kind
  && letRes::Def(_, def_id) = cx.qpath_res(qpath, fn_expr.hir_id)
 {

clippy_lints/src/exit.rs

@@ -43,7 +43,7 @@ declare_lint_pass!(Exit => [EXIT]);
 
 impl<'tcx>LateLintPass<'tcx>forExit{
 fncheck_expr(&mutself,cx:&LateContext<'tcx>,e:&'tcxExpr<'_>){
-ifletExprKind::Call(path_expr,_args) = e.kind
+ifletExprKind::Call(path_expr,[_]) = e.kind
  && letExprKind::Path(ref path) = path_expr.kind
  && letSome(def_id) = cx.qpath_res(path, path_expr.hir_id).opt_def_id()
  && cx.tcx.is_diagnostic_item(sym::process_exit, def_id)

clippy_lints/src/explicit_write.rs

@@ -57,7 +57,7 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitWrite {
  && unwrap_fun.ident.name == sym::unwrap
 // match call to write_fmt
  && letExprKind::MethodCall(write_fun, write_recv,[write_arg], _) = *look_in_block(cx,&write_call.kind)
- && letExprKind::Call(write_recv_path,_) = write_recv.kind
+ && letExprKind::Call(write_recv_path,[]) = write_recv.kind
  && write_fun.ident.name == sym!(write_fmt)
  && letSome(def_id) = path_def_id(cx, write_recv_path)
 {

clippy_lints/src/floating_point_arithmetic.rs

@@ -436,12 +436,12 @@ fn check_expm1(cx: &LateContext<'_>, expr: &Expr<'_>) {
  lhs,
  rhs,
 ) = expr.kind
+ && letExprKind::MethodCall(path, self_arg,[], _) = &lhs.kind
+ && path.ident.name.as_str() == "exp"
  && cx.typeck_results().expr_ty(lhs).is_floating_point()
  && letSome(value) = ConstEvalCtxt::new(cx).eval(rhs)
  && (F32(1.0) == value || F64(1.0) == value)
- && letExprKind::MethodCall(path, self_arg, ..) = &lhs.kind
  && cx.typeck_results().expr_ty(self_arg).is_floating_point()
- && path.ident.name.as_str() == "exp"
 {
 span_lint_and_sugg(
  cx,

clippy_lints/src/format_impl.rs

@@ -151,7 +151,7 @@ struct FormatImplExpr<'a, 'tcx> {
 implFormatImplExpr<'_,'_>{
 fncheck_to_string_in_display(&self){
 ifself.format_trait_impl.name == sym::Display
- && letExprKind::MethodCall(path, self_arg,..) = self.expr.kind
+ && letExprKind::MethodCall(path, self_arg,[], _) = self.expr.kind
 // Get the hir_id of the object we are calling the method on
 // Is the method to_string() ?
  && path.ident.name == sym::to_string

clippy_lints/src/if_let_mutex.rs

@@ -82,7 +82,7 @@ fn mutex_lock_call<'tcx>(
 expr:&'tcxExpr<'_>,
 op_mutex:Option<&'tcxExpr<'_>>,
 ) -> ControlFlow<&'tcxExpr<'tcx>>{
-ifletExprKind::MethodCall(path, self_arg,..) = &expr.kind
+ifletExprKind::MethodCall(path, self_arg,[], _) = &expr.kind
  && path.ident.as_str() == "lock"
  && let ty = cx.typeck_results().expr_ty(self_arg).peel_refs()
  && is_type_diagnostic_item(cx, ty, sym::Mutex)