X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Futils%2Fmod.rs;h=e83371f8b99a4c3007641b1661fbc6745e318e6b;hb=bdad7900f4558672ca02b24a0a079b05391acaf9;hp=8297b9d128dde9b863c03e62b36c61f779cce849;hpb=d5713898acd3e9afe04223522aad50c9da8f05e2;p=rust.git diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs index 8297b9d128d..e83371f8b99 100644 --- a/clippy_lints/src/utils/mod.rs +++ b/clippy_lints/src/utils/mod.rs @@ -14,6 +14,7 @@ pub mod higher; mod hir_utils; pub mod inspector; +#[cfg(feature = "internal-lints")] pub mod internal_lints; pub mod numeric_literal; pub mod paths; @@ -21,22 +22,26 @@ pub mod qualify_min_const_fn; pub mod sugg; pub mod usage; +pub mod visitors; pub use self::attrs::*; pub use self::diagnostics::*; pub use self::hir_utils::{both, eq_expr_value, over, SpanlessEq, SpanlessHash}; use std::borrow::Cow; +use std::collections::hash_map::Entry; +use std::hash::BuildHasherDefault; use std::mem; use if_chain::if_chain; use rustc_ast::ast::{self, Attribute, LitKind}; use rustc_attr as attr; +use rustc_data_structures::fx::FxHashMap; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE}; -use rustc_hir::intravisit::{NestedVisitorMap, Visitor}; +use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor}; use rustc_hir::Node; use rustc_hir::{ def, Arm, Block, Body, Constness, Crate, Expr, ExprKind, FnDecl, HirId, ImplItem, ImplItemKind, Item, ItemKind, @@ -47,8 +52,11 @@ use rustc_middle::hir::map::Map; use rustc_middle::ty::subst::{GenericArg, GenericArgKind}; use rustc_middle::ty::{self, layout::IntegerExt, Ty, TyCtxt, TypeFoldable}; +use rustc_semver::RustcVersion; +use rustc_session::Session; use rustc_span::hygiene::{ExpnKind, MacroKind}; use rustc_span::source_map::original_sp; +use rustc_span::sym as rustc_sym; use rustc_span::symbol::{self, kw, Symbol}; use rustc_span::{BytePos, Pos, Span, DUMMY_SP}; use rustc_target::abi::Integer; @@ -57,6 +65,49 @@ use crate::consts::{constant, Constant}; +pub fn parse_msrv(msrv: &str, sess: Option<&Session>, span: Option) -> Option { + if let Ok(version) = RustcVersion::parse(msrv) { + return Some(version); + } else if let Some(sess) = sess { + if let Some(span) = span { + sess.span_err(span, &format!("`{}` is not a valid Rust version", msrv)); + } + } + None +} + +pub fn meets_msrv(msrv: Option<&RustcVersion>, lint_msrv: &RustcVersion) -> bool { + msrv.map_or(true, |msrv| msrv.meets(*lint_msrv)) +} + +macro_rules! extract_msrv_attr { + (LateContext) => { + extract_msrv_attr!(@LateContext, ()); + }; + (EarlyContext) => { + extract_msrv_attr!(@EarlyContext); + }; + (@$context:ident$(, $call:tt)?) => { + fn enter_lint_attrs(&mut self, cx: &rustc_lint::$context<'tcx>, attrs: &'tcx [rustc_ast::ast::Attribute]) { + use $crate::utils::get_unique_inner_attr; + match get_unique_inner_attr(cx.sess$($call)?, attrs, "msrv") { + Some(msrv_attr) => { + if let Some(msrv) = msrv_attr.value_str() { + self.msrv = $crate::utils::parse_msrv( + &msrv.to_string(), + Some(cx.sess$($call)?), + Some(msrv_attr.span), + ); + } else { + cx.sess$($call)?.span_err(msrv_attr.span, "bad clippy attribute"); + } + }, + _ => (), + } + } + }; +} + /// Returns `true` if the two spans come from differing expansions (i.e., one is /// from a macro and one isn't). #[must_use] @@ -268,6 +319,7 @@ pub fn path_to_res(cx: &LateContext<'_>, path: &[&str]) -> Option { krate: *krate, index: CRATE_DEF_INDEX, }; + let mut current_item = None; let mut items = cx.tcx.item_children(krate); let mut path_it = path.iter().skip(1).peekable(); @@ -277,6 +329,12 @@ pub fn path_to_res(cx: &LateContext<'_>, path: &[&str]) -> Option { None => return None, }; + // `get_def_path` seems to generate these empty segments for extern blocks. + // We can just ignore them. + if segment.is_empty() { + continue; + } + let result = SmallVec::<[_; 8]>::new(); for item in mem::replace(&mut items, cx.tcx.arena.alloc_slice(&result)).iter() { if item.ident.name.as_str() == *segment { @@ -284,10 +342,28 @@ pub fn path_to_res(cx: &LateContext<'_>, path: &[&str]) -> Option { return Some(item.res); } + current_item = Some(item); items = cx.tcx.item_children(item.res.def_id()); break; } } + + // The segment isn't a child_item. + // Try to find it under an inherent impl. + if_chain! { + if path_it.peek().is_none(); + if let Some(current_item) = current_item; + let item_def_id = current_item.res.def_id(); + if cx.tcx.def_kind(item_def_id) == DefKind::Struct; + then { + // Bad `find_map` suggestion. See #4193. + #[allow(clippy::find_map)] + return cx.tcx.inherent_impls(item_def_id).iter() + .flat_map(|&impl_def_id| cx.tcx.item_children(impl_def_id)) + .find(|item| item.ident.name.as_str() == *segment) + .map(|item| item.res); + } + } } } else { None @@ -334,7 +410,10 @@ pub fn implements_trait<'tcx>( if ty.has_infer_types() { return false; } - let ty = cx.tcx.erase_regions(&ty); + let ty = cx.tcx.erase_regions(ty); + if ty.has_escaping_bound_vars() { + return false; + } let ty_params = cx.tcx.mk_substs(ty_params.iter()); cx.tcx.type_implements_trait((trait_id, ty, ty_params, cx.param_env)) } @@ -439,6 +518,13 @@ pub fn is_entrypoint_fn(cx: &LateContext<'_>, def_id: DefId) -> bool { .map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id.to_def_id()) } +/// Returns `true` if the expression is in the program's `#[panic_handler]`. +pub fn is_in_panic_handler(cx: &LateContext<'_>, e: &Expr<'_>) -> bool { + let parent = cx.tcx.hir().get_parent_item(e.hir_id); + let def_id = cx.tcx.hir().local_def_id(parent).to_def_id(); + Some(def_id) == cx.tcx.lang_items().panic_impl() +} + /// Gets the name of the item the expression is in, if available. pub fn get_item_name(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option { let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id); @@ -487,6 +573,67 @@ pub fn contains_name(name: Symbol, expr: &Expr<'_>) -> bool { cn.result } +/// Returns `true` if `expr` contains a return expression +pub fn contains_return(expr: &hir::Expr<'_>) -> bool { + struct RetCallFinder { + found: bool, + } + + impl<'tcx> hir::intravisit::Visitor<'tcx> for RetCallFinder { + type Map = Map<'tcx>; + + fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) { + if self.found { + return; + } + if let hir::ExprKind::Ret(..) = &expr.kind { + self.found = true; + } else { + hir::intravisit::walk_expr(self, expr); + } + } + + fn nested_visit_map(&mut self) -> hir::intravisit::NestedVisitorMap { + hir::intravisit::NestedVisitorMap::None + } + } + + let mut visitor = RetCallFinder { found: false }; + visitor.visit_expr(expr); + visitor.found +} + +struct FindMacroCalls<'a, 'b> { + names: &'a [&'b str], + result: Vec, +} + +impl<'a, 'b, 'tcx> Visitor<'tcx> for FindMacroCalls<'a, 'b> { + type Map = Map<'tcx>; + + fn visit_expr(&mut self, expr: &'tcx Expr<'_>) { + if self.names.iter().any(|fun| is_expn_of(expr.span, fun).is_some()) { + self.result.push(expr.span); + } + // and check sub-expressions + intravisit::walk_expr(self, expr); + } + + fn nested_visit_map(&mut self) -> NestedVisitorMap { + NestedVisitorMap::None + } +} + +/// Finds calls of the specified macros in a function body. +pub fn find_macro_calls(names: &[&str], body: &Body<'_>) -> Vec { + let mut fmc = FindMacroCalls { + names, + result: Vec::new(), + }; + fmc.visit_expr(&body.value); + fmc.result +} + /// Converts a span to a code snippet if available, otherwise use default. /// /// This is useful if you want to provide suggestions for your lint or more generally, if you want @@ -630,6 +777,35 @@ pub fn indent_of(cx: &T, span: Span) -> Option { snippet_opt(cx, line_span(cx, span)).and_then(|snip| snip.find(|c: char| !c.is_whitespace())) } +/// Returns the positon just before rarrow +/// +/// ```rust,ignore +/// fn into(self) -> () {} +/// ^ +/// // in case of unformatted code +/// fn into2(self)-> () {} +/// ^ +/// fn into3(self) -> () {} +/// ^ +/// ``` +#[allow(clippy::needless_pass_by_value)] +pub fn position_before_rarrow(s: String) -> Option { + s.rfind("->").map(|rpos| { + let mut rpos = rpos; + let chars: Vec = s.chars().collect(); + while rpos > 1 { + if let Some(c) = chars.get(rpos - 1) { + if c.is_whitespace() { + rpos -= 1; + continue; + } + } + break; + } + rpos + }) +} + /// Extends the span to the beginning of the spans line, incl. whitespaces. /// /// ```rust,ignore @@ -858,7 +1034,7 @@ pub fn is_direct_expn_of(span: Span, name: &str) -> Option { pub fn return_ty<'tcx>(cx: &LateContext<'tcx>, fn_item: hir::HirId) -> Ty<'tcx> { let fn_def_id = cx.tcx.hir().local_def_id(fn_item); let ret_ty = cx.tcx.fn_sig(fn_def_id).output(); - cx.tcx.erase_late_bound_regions(&ret_ty) + cx.tcx.erase_late_bound_regions(ret_ty) } /// Walks into `ty` and returns `true` if any inner type is the same as `other_ty` @@ -946,7 +1122,7 @@ fn are_refutable<'a, I: Iterator>>(cx: &LateContext<'_>, mut /// Checks for the `#[automatically_derived]` attribute all `#[derive]`d /// implementations have. pub fn is_automatically_derived(attrs: &[ast::Attribute]) -> bool { - attrs.iter().any(|attr| attr.has_name(sym!(automatically_derived))) + attrs.iter().any(|attr| attr.has_name(rustc_sym::automatically_derived)) } /// Remove blocks around an expression. @@ -1167,7 +1343,7 @@ pub fn has_iter_method(cx: &LateContext<'_>, probably_ref_ty: Ty<'_>) -> Option< /// Usage: /// /// ```rust,ignore -/// if let Some(args) = match_function_call(cx, begin_panic_call, &paths::BEGIN_PANIC); +/// if let Some(args) = match_function_call(cx, cmp_max_call, &paths::CMP_MAX); /// ``` pub fn match_function_call<'tcx>( cx: &LateContext<'tcx>, @@ -1191,7 +1367,7 @@ pub fn match_function_call<'tcx>( pub fn is_normalizable<'tcx>(cx: &LateContext<'tcx>, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool { cx.tcx.infer_ctxt().enter(|infcx| { let cause = rustc_middle::traits::ObligationCause::dummy(); - infcx.at(&cause, param_env).normalize(&ty).is_ok() + infcx.at(&cause, param_env).normalize(ty).is_ok() }) } @@ -1202,6 +1378,24 @@ pub fn match_def_path<'tcx>(cx: &LateContext<'tcx>, did: DefId, syms: &[&str]) - cx.match_def_path(did, &syms) } +pub fn match_panic_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx [Expr<'tcx>]> { + match_function_call(cx, expr, &paths::BEGIN_PANIC) + .or_else(|| match_function_call(cx, expr, &paths::BEGIN_PANIC_FMT)) + .or_else(|| match_function_call(cx, expr, &paths::PANIC_ANY)) + .or_else(|| match_function_call(cx, expr, &paths::PANICKING_PANIC)) + .or_else(|| match_function_call(cx, expr, &paths::PANICKING_PANIC_FMT)) + .or_else(|| match_function_call(cx, expr, &paths::PANICKING_PANIC_STR)) +} + +pub fn match_panic_def_id(cx: &LateContext<'_>, did: DefId) -> bool { + match_def_path(cx, did, &paths::BEGIN_PANIC) + || match_def_path(cx, did, &paths::BEGIN_PANIC_FMT) + || match_def_path(cx, did, &paths::PANIC_ANY) + || match_def_path(cx, did, &paths::PANICKING_PANIC) + || match_def_path(cx, did, &paths::PANICKING_PANIC_FMT) + || match_def_path(cx, did, &paths::PANICKING_PANIC_STR) +} + /// Returns the list of condition expressions and the list of blocks in a /// sequence of `if/else`. /// E.g., this returns `([a, b], [c, d, e])` for the expression @@ -1320,7 +1514,7 @@ pub fn is_must_use_func_call(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { pub fn is_no_std_crate(krate: &Crate<'_>) -> bool { krate.item.attrs.iter().any(|attr| { - if let ast::AttrKind::Normal(ref attr) = attr.kind { + if let ast::AttrKind::Normal(ref attr, _) = attr.kind { attr.path == symbol::sym::no_std } else { false @@ -1337,7 +1531,7 @@ pub fn is_no_std_crate(krate: &Crate<'_>) -> bool { /// ``` pub fn is_trait_impl_item(cx: &LateContext<'_>, hir_id: HirId) -> bool { if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) { - matches!(item.kind, ItemKind::Impl{ of_trait: Some(_), .. }) + matches!(item.kind, ItemKind::Impl { of_trait: Some(_), .. }) } else { false } @@ -1440,6 +1634,41 @@ pub fn is_slice_of_primitives(cx: &LateContext<'_>, expr: &Expr<'_>) -> Option(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)> +where + Hash: Fn(&T) -> u64, + Eq: Fn(&T, &T) -> bool, +{ + if exprs.len() == 2 && eq(&exprs[0], &exprs[1]) { + return vec![(&exprs[0], &exprs[1])]; + } + + let mut match_expr_list: Vec<(&T, &T)> = Vec::new(); + + let mut map: FxHashMap<_, Vec<&_>> = + FxHashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default()); + + for expr in exprs { + match map.entry(hash(expr)) { + Entry::Occupied(mut o) => { + for o in o.get() { + if eq(o, expr) { + match_expr_list.push((o, expr)); + } + } + o.get_mut().push(expr); + }, + Entry::Vacant(v) => { + v.insert(vec![expr]); + }, + } + } + + match_expr_list +} + #[macro_export] macro_rules! unwrap_cargo_metadata { ($cx: ident, $lint: ident, $deps: expr) => {{