-/// checks for attributes
+//! checks for attributes
-use rustc::plugin::Registry;
use rustc::lint::*;
-use syntax::ast::*;
-use syntax::ptr::P;
+use rustc_front::hir::*;
+use reexport::*;
+use semver::Version;
use syntax::codemap::Span;
-use syntax::parse::token::InternedString;
+use syntax::attr::*;
+use syntax::ast::{Attribute, Lit, Lit_, MetaList, MetaWord, MetaNameValue};
+use utils::{in_macro, match_path, span_lint, BEGIN_UNWIND};
+/// **What it does:** This lint `Warn`s on items annotated with `#[inline(always)]`, unless the annotated function is empty or simply panics.
+///
+/// **Why is this bad?** While there are valid uses of this annotation (and once you know when to use it, by all means `allow` this lint), it's a common newbie-mistake to pepper one's code with it.
+///
+/// As a rule of thumb, before slapping `#[inline(always)]` on a function, measure if that additional function call really affects your runtime profile sufficiently to make up for the increase in compile time.
+///
+/// **Known problems:** False positives, big time. This lint is meant to be deactivated by everyone doing serious performance work. This means having done the measurement.
+///
+/// **Example:**
+/// ```
+/// #[inline(always)]
+/// fn not_quite_hot_code(..) { ... }
+/// ```
declare_lint! { pub INLINE_ALWAYS, Warn,
- "#[inline(always)] is usually a bad idea."}
+ "`#[inline(always)]` is a bad idea in most cases" }
+/// **What it does:** This lint `Warn`s on `#[deprecated]` annotations with a `since` field that is not a valid semantic version..
+///
+/// **Why is this bad?** For checking the version of the deprecation, it must be valid semver. Failing that, the contained information is useless.
+///
+/// **Known problems:** None
+///
+/// **Example:**
+/// ```
+/// #[deprecated(since = "forever")]
+/// fn something_else(..) { ... }
+/// ```
+declare_lint! { pub DEPRECATED_SEMVER, Warn,
+ "`Warn` on `#[deprecated(since = \"x\")]` where x is not semver" }
#[derive(Copy,Clone)]
pub struct AttrPass;
impl LintPass for AttrPass {
fn get_lints(&self) -> LintArray {
- lint_array!(INLINE_ALWAYS)
+ lint_array!(INLINE_ALWAYS, DEPRECATED_SEMVER)
+ }
+}
+
+impl LateLintPass for AttrPass {
+ fn check_attribute(&mut self, cx: &LateContext, attr: &Attribute) {
+ if let MetaList(ref name, ref items) = attr.node.value.node {
+ if items.is_empty() || name != &"deprecated" {
+ return;
+ }
+ for ref item in items {
+ if let MetaNameValue(ref name, ref lit) = item.node {
+ if name == &"since" {
+ check_semver(cx, item.span, lit);
+ }
+ }
+ }
+ }
}
- fn check_item(&mut self, cx: &Context, item: &Item) {
- check_attrs(cx, &item.ident, &item.attrs)
- }
-
- fn check_impl_item(&mut self, cx: &Context, item: &ImplItem) {
- check_attrs(cx, &item.ident, &item.attrs)
- }
-
- fn check_trait_item(&mut self, cx: &Context, item: &TraitItem) {
- check_attrs(cx, &item.ident, &item.attrs)
- }
-}
-
-fn check_attrs(cx: &Context, ident: &Ident, attrs: &[Attribute]) {
- for attr in attrs {
- if let MetaList(ref inline, ref values) = attr.node.value.node {
- if values.len() != 1 || inline != &"inline" { continue; }
- if let MetaWord(ref always) = values[0].node {
- if always != &"always" { continue; }
- cx.span_lint(INLINE_ALWAYS, attr.span, &format!(
- "You have declared #[inline(always)] on {}. This \
- is usually a bad idea. Are you sure?",
- ident.as_str()));
- }
- }
- }
+ fn check_item(&mut self, cx: &LateContext, item: &Item) {
+ if is_relevant_item(item) {
+ check_attrs(cx, item.span, &item.name, &item.attrs)
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext, item: &ImplItem) {
+ if is_relevant_impl(item) {
+ check_attrs(cx, item.span, &item.name, &item.attrs)
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext, item: &TraitItem) {
+ if is_relevant_trait(item) {
+ check_attrs(cx, item.span, &item.name, &item.attrs)
+ }
+ }
+}
+
+fn is_relevant_item(item: &Item) -> bool {
+ if let ItemFn(_, _, _, _, _, ref block) = item.node {
+ is_relevant_block(block)
+ } else {
+ false
+ }
+}
+
+fn is_relevant_impl(item: &ImplItem) -> bool {
+ match item.node {
+ ImplItemKind::Method(_, ref block) => is_relevant_block(block),
+ _ => false,
+ }
+}
+
+fn is_relevant_trait(item: &TraitItem) -> bool {
+ match item.node {
+ MethodTraitItem(_, None) => true,
+ MethodTraitItem(_, Some(ref block)) => is_relevant_block(block),
+ _ => false,
+ }
+}
+
+fn is_relevant_block(block: &Block) -> bool {
+ for stmt in &block.stmts {
+ match stmt.node {
+ StmtDecl(_, _) => return true,
+ StmtExpr(ref expr, _) | StmtSemi(ref expr, _) => {
+ return is_relevant_expr(expr);
+ }
+ }
+ }
+ block.expr.as_ref().map_or(false, |e| is_relevant_expr(e))
+}
+
+fn is_relevant_expr(expr: &Expr) -> bool {
+ match expr.node {
+ ExprBlock(ref block) => is_relevant_block(block),
+ ExprRet(Some(ref e)) => is_relevant_expr(e),
+ ExprRet(None) | ExprBreak(_) => false,
+ ExprCall(ref path_expr, _) => {
+ if let ExprPath(_, ref path) = path_expr.node {
+ !match_path(path, &BEGIN_UNWIND)
+ } else {
+ true
+ }
+ }
+ _ => true,
+ }
+}
+
+fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
+ if in_macro(cx, span) {
+ return;
+ }
+
+ for attr in attrs {
+ if let MetaList(ref inline, ref values) = attr.node.value.node {
+ if values.len() != 1 || inline != &"inline" {
+ continue;
+ }
+ if let MetaWord(ref always) = values[0].node {
+ if always != &"always" {
+ continue;
+ }
+ span_lint(cx,
+ INLINE_ALWAYS,
+ attr.span,
+ &format!("you have declared `#[inline(always)]` on `{}`. This is usually a bad idea",
+ name));
+ }
+ }
+ }
+}
+
+fn check_semver(cx: &LateContext, span: Span, lit: &Lit) {
+ if let Lit_::LitStr(ref is, _) = lit.node {
+ if Version::parse(&*is).is_ok() {
+ return;
+ }
+ }
+ span_lint(cx,
+ DEPRECATED_SEMVER,
+ span,
+ "the since field must contain a semver-compliant version");
}
projects / rust.git / blobdiff