//! checks for attributes
-use reexport::*;
-use rustc::lint::*;
+use crate::reexport::*;
+use crate::utils::{
+ in_macro, last_line_of_span, match_def_path, opt_def_id, paths, snippet_opt, span_lint, span_lint_and_then,
+ without_block_comments,
+};
use rustc::hir::*;
+use rustc::lint::*;
use rustc::ty::{self, TyCtxt};
use semver::Version;
-use syntax::ast::{Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
+use syntax::ast::{AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
use syntax::codemap::Span;
-use utils::{in_macro, match_def_path, paths, snippet_opt, span_lint, span_lint_and_then};
/// **What it does:** Checks for items annotated with `#[inline(always)]`,
/// unless the annotated function is empty or simply panics.
/// #[inline(always)]
/// fn not_quite_hot_code(..) { ... }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub INLINE_ALWAYS,
- Warn,
+ pedantic,
"use of `#[inline(always)]`"
}
/// #[allow(unused_import)]
/// use foo::bar;
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub USELESS_ATTRIBUTE,
- Warn,
+ correctness,
"use of lint attributes on `extern crate` items"
}
/// #[deprecated(since = "forever")]
/// fn something_else(..) { ... }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub DEPRECATED_SEMVER,
- Warn,
+ correctness,
"use of `#[deprecated(since = \"x\")]` where x is not semver"
}
+/// **What it does:** Checks for empty lines after outer attributes
+///
+/// **Why is this bad?**
+/// Most likely the attribute was meant to be an inner attribute using a '!'.
+/// If it was meant to be an outer attribute, then the following item
+/// should not be separated by empty lines.
+///
+/// **Known problems:** Can cause false positives.
+///
+/// From the clippy side it's difficult to detect empty lines between an attributes and the
+/// following item because empty lines and comments are not part of the AST. The parsing
+/// currently works for basic cases but is not perfect.
+///
+/// **Example:**
+/// ```rust
+/// // Bad
+/// #[inline(always)]
+///
+/// fn not_quite_good_code(..) { ... }
+///
+/// // Good (as inner attribute)
+/// #![inline(always)]
+///
+/// fn this_is_fine(..) { ... }
+///
+/// // Good (as outer attribute)
+/// #[inline(always)]
+/// fn this_is_fine_too(..) { ... }
+/// ```
+declare_clippy_lint! {
+ pub EMPTY_LINE_AFTER_OUTER_ATTR,
+ nursery,
+ "empty line after outer attribute"
+}
+
#[derive(Copy, Clone)]
pub struct AttrPass;
impl LintPass for AttrPass {
fn get_lints(&self) -> LintArray {
- lint_array!(INLINE_ALWAYS, DEPRECATED_SEMVER, USELESS_ATTRIBUTE)
+ lint_array!(
+ INLINE_ALWAYS,
+ DEPRECATED_SEMVER,
+ USELESS_ATTRIBUTE,
+ EMPTY_LINE_AFTER_OUTER_ATTR
+ )
}
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AttrPass {
fn check_attribute(&mut self, cx: &LateContext<'a, 'tcx>, attr: &'tcx Attribute) {
if let Some(ref items) = attr.meta_item_list() {
- if items.is_empty() || attr.name().map_or(true, |n| n != "deprecated") {
+ if items.is_empty() || attr.name() != "deprecated" {
return;
}
for item in items {
- if_let_chain! {[
- let NestedMetaItemKind::MetaItem(ref mi) = item.node,
- let MetaItemKind::NameValue(ref lit) = mi.node,
- mi.name() == "since",
- ], {
- check_semver(cx, item.span, lit);
- }}
+ if_chain! {
+ if let NestedMetaItemKind::MetaItem(ref mi) = item.node;
+ if let MetaItemKind::NameValue(ref lit) = mi.node;
+ if mi.name() == "since";
+ then {
+ check_semver(cx, item.span, lit);
+ }
+ }
}
}
}
fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
if is_relevant_item(cx.tcx, item) {
- check_attrs(cx, item.span, &item.name, &item.attrs)
+ check_attrs(cx, item.span, item.name, &item.attrs)
}
match item.node {
ItemExternCrate(_) | ItemUse(_, _) => {
for attr in &item.attrs {
if let Some(ref lint_list) = attr.meta_item_list() {
- if let Some(name) = attr.name() {
- match &*name.as_str() {
- "allow" | "warn" | "deny" | "forbid" => {
- // whitelist `unused_imports` and `deprecated`
- for lint in lint_list {
- if is_word(lint, "unused_imports") || is_word(lint, "deprecated") {
- if let ItemUse(_, _) = item.node {
- return;
- }
+ match &*attr.name().as_str() {
+ "allow" | "warn" | "deny" | "forbid" => {
+ // whitelist `unused_imports` and `deprecated`
+ for lint in lint_list {
+ if is_word(lint, "unused_imports") || is_word(lint, "deprecated") {
+ if let ItemUse(_, _) = item.node {
+ return;
}
}
- if let Some(mut sugg) = snippet_opt(cx, attr.span) {
- if sugg.len() > 1 {
- span_lint_and_then(
- cx,
- USELESS_ATTRIBUTE,
- attr.span,
- "useless lint attribute",
- |db| {
- sugg.insert(1, '!');
- db.span_suggestion(
- attr.span,
- "if you just forgot a `!`, use",
- sugg,
- );
- },
- );
- }
+ }
+ let line_span = last_line_of_span(cx, attr.span);
+
+ if let Some(mut sugg) = snippet_opt(cx, line_span) {
+ if sugg.contains("#[") {
+ span_lint_and_then(
+ cx,
+ USELESS_ATTRIBUTE,
+ line_span,
+ "useless lint attribute",
+ |db| {
+ sugg = sugg.replacen("#[", "#![", 1);
+ db.span_suggestion(line_span, "if you just forgot a `!`, use", sugg);
+ },
+ );
}
- },
- _ => {},
- }
+ }
+ },
+ _ => {},
}
}
}
fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx ImplItem) {
if is_relevant_impl(cx.tcx, item) {
- check_attrs(cx, item.span, &item.name, &item.attrs)
+ check_attrs(cx, item.span, item.ident.name, &item.attrs)
}
}
fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem) {
if is_relevant_trait(cx.tcx, item) {
- check_attrs(cx, item.span, &item.name, &item.attrs)
+ check_attrs(cx, item.span, item.ident.name, &item.attrs)
}
}
}
fn is_relevant_item(tcx: TyCtxt, item: &Item) -> bool {
- if let ItemFn(_, _, _, _, _, eid) = item.node {
+ if let ItemFn(_, _, _, eid) = item.node {
is_relevant_expr(tcx, tcx.body_tables(eid), &tcx.hir.body(eid).value)
} else {
- false
+ true
}
}
StmtExpr(ref expr, _) | StmtSemi(ref expr, _) => is_relevant_expr(tcx, tables, expr),
}
} else {
- block
- .expr
- .as_ref()
- .map_or(false, |e| is_relevant_expr(tcx, tables, e))
+ block.expr.as_ref().map_or(false, |e| is_relevant_expr(tcx, tables, e))
}
}
fn is_relevant_expr(tcx: TyCtxt, tables: &ty::TypeckTables, expr: &Expr) -> bool {
match expr.node {
- ExprBlock(ref block) => is_relevant_block(tcx, tables, block),
+ ExprBlock(ref block, _) => is_relevant_block(tcx, tables, block),
ExprRet(Some(ref e)) => is_relevant_expr(tcx, tables, e),
ExprRet(None) | ExprBreak(_, None) => false,
ExprCall(ref path_expr, _) => if let ExprPath(ref qpath) = path_expr.node {
- let fun_id = tables.qpath_def(qpath, path_expr.hir_id).def_id();
- !match_def_path(tcx, fun_id, &paths::BEGIN_PANIC)
+ if let Some(fun_id) = opt_def_id(tables.qpath_def(qpath, path_expr.hir_id)) {
+ !match_def_path(tcx, fun_id, &paths::BEGIN_PANIC)
+ } else {
+ true
+ }
} else {
true
},
}
}
-fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
+fn check_attrs(cx: &LateContext, span: Span, name: Name, attrs: &[Attribute]) {
if in_macro(span) {
return;
}
for attr in attrs {
+ if attr.is_sugared_doc {
+ return;
+ }
+ if attr.style == AttrStyle::Outer {
+ if attr.tokens.is_empty() || !is_present_in_source(cx, attr.span) {
+ return;
+ }
+
+ let begin_of_attr_to_item = Span::new(attr.span.lo(), span.lo(), span.ctxt());
+ let end_of_attr_to_item = Span::new(attr.span.hi(), span.lo(), span.ctxt());
+
+ if let Some(snippet) = snippet_opt(cx, end_of_attr_to_item) {
+ let lines = snippet.split('\n').collect::<Vec<_>>();
+ let lines = without_block_comments(lines);
+
+ if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 {
+ span_lint(
+ cx,
+ EMPTY_LINE_AFTER_OUTER_ATTR,
+ begin_of_attr_to_item,
+ "Found an empty line after an outer attribute. Perhaps you forgot to add a '!' to make it an inner attribute?"
+ );
+ }
+ }
+ }
+
if let Some(ref values) = attr.meta_item_list() {
- if values.len() != 1 || attr.name().map_or(true, |n| n != "inline") {
+ if values.len() != 1 || attr.name() != "inline" {
continue;
}
if is_word(&values[0], "always") {
false
}
}
+
+// If the snippet is empty, it's an attribute that was inserted during macro
+// expansion and we want to ignore those, because they could come from external
+// sources that the user has no control over.
+// For some reason these attributes don't have any expansion info on them, so
+// we have to check it this way until there is a better way.
+fn is_present_in_source(cx: &LateContext, span: Span) -> bool {
+ if let Some(snippet) = snippet_opt(cx, span) {
+ if snippet.is_empty() {
+ return false;
+ }
+ }
+ true
+}
projects / rust.git / blobdiff