-use crate::utils::{implements_trait, is_entrypoint_fn, is_type_diagnostic_item, return_ty, span_lint};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_note};
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
+use clippy_utils::{is_entrypoint_fn, is_expn_of, match_panic_def_id, method_chain_args, return_ty};
use if_chain::if_chain;
use itertools::Itertools;
use rustc_ast::ast::{Async, AttrKind, Attribute, FnKind, FnRetTy, ItemKind};
use rustc_errors::emitter::EmitterWriter;
use rustc_errors::Handler;
use rustc_hir as hir;
+use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
+use rustc_hir::{AnonConst, Expr, ExprKind, QPath};
use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
use rustc_middle::lint::in_external_macro;
use rustc_middle::ty;
use rustc_parse::maybe_new_parser_from_source_str;
"`pub fn` returns `Result` without `# Errors` in doc comment"
}
+declare_clippy_lint! {
+ /// **What it does:** Checks the doc comments of publicly visible functions that
+ /// may panic and warns if there is no `# Panics` section.
+ ///
+ /// **Why is this bad?** Documenting the scenarios in which panicking occurs
+ /// can help callers who do not want to panic to avoid those situations.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ ///
+ /// Since the following function may panic it has a `# Panics` section in
+ /// its doc comment:
+ ///
+ /// ```rust
+ /// /// # Panics
+ /// ///
+ /// /// Will panic if y is 0
+ /// pub fn divide_by(x: i32, y: i32) -> i32 {
+ /// if y == 0 {
+ /// panic!("Cannot divide by 0")
+ /// } else {
+ /// x / y
+ /// }
+ /// }
+ /// ```
+ pub MISSING_PANICS_DOC,
+ pedantic,
+ "`pub fn` may panic without `# Panics` in doc comment"
+}
+
declare_clippy_lint! {
/// **What it does:** Checks for `fn main() { .. }` in doctests
///
}
}
-impl_lint_pass!(DocMarkdown => [DOC_MARKDOWN, MISSING_SAFETY_DOC, MISSING_ERRORS_DOC, NEEDLESS_DOCTEST_MAIN]);
+impl_lint_pass!(DocMarkdown =>
+ [DOC_MARKDOWN, MISSING_SAFETY_DOC, MISSING_ERRORS_DOC, MISSING_PANICS_DOC, NEEDLESS_DOCTEST_MAIN]
+);
impl<'tcx> LateLintPass<'tcx> for DocMarkdown {
- fn check_crate(&mut self, cx: &LateContext<'tcx>, krate: &'tcx hir::Crate<'_>) {
- check_attrs(cx, &self.valid_idents, &krate.item.attrs);
+ fn check_crate(&mut self, cx: &LateContext<'tcx>, _: &'tcx hir::Crate<'_>) {
+ let attrs = cx.tcx.hir().attrs(hir::CRATE_HIR_ID);
+ check_attrs(cx, &self.valid_idents, attrs);
}
fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'_>) {
- let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let headers = check_attrs(cx, &self.valid_idents, attrs);
match item.kind {
hir::ItemKind::Fn(ref sig, _, body_id) => {
- if !(is_entrypoint_fn(cx, cx.tcx.hir().local_def_id(item.hir_id).to_def_id())
- || in_external_macro(cx.tcx.sess, item.span))
- {
- lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
+ if !(is_entrypoint_fn(cx, item.def_id.to_def_id()) || in_external_macro(cx.tcx.sess, item.span)) {
+ let body = cx.tcx.hir().body(body_id);
+ let mut fpu = FindPanicUnwrap {
+ cx,
+ typeck_results: cx.tcx.typeck(item.def_id),
+ panic_span: None,
+ };
+ fpu.visit_expr(&body.value);
+ lint_for_missing_headers(
+ cx,
+ item.hir_id(),
+ item.span,
+ sig,
+ headers,
+ Some(body_id),
+ fpu.panic_span,
+ );
}
},
hir::ItemKind::Impl(ref impl_) => {
}
fn check_trait_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
- let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let headers = check_attrs(cx, &self.valid_idents, attrs);
if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
if !in_external_macro(cx.tcx.sess, item.span) {
- lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, None);
+ lint_for_missing_headers(cx, item.hir_id(), item.span, sig, headers, None, None);
}
}
}
fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::ImplItem<'_>) {
- let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+ let attrs = cx.tcx.hir().attrs(item.hir_id());
+ let headers = check_attrs(cx, &self.valid_idents, attrs);
if self.in_trait_impl || in_external_macro(cx.tcx.sess, item.span) {
return;
}
if let hir::ImplItemKind::Fn(ref sig, body_id) = item.kind {
- lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
+ let body = cx.tcx.hir().body(body_id);
+ let mut fpu = FindPanicUnwrap {
+ cx,
+ typeck_results: cx.tcx.typeck(item.def_id),
+ panic_span: None,
+ };
+ fpu.visit_expr(&body.value);
+ lint_for_missing_headers(
+ cx,
+ item.hir_id(),
+ item.span,
+ sig,
+ headers,
+ Some(body_id),
+ fpu.panic_span,
+ );
}
}
}
sig: &hir::FnSig<'_>,
headers: DocHeaders,
body_id: Option<hir::BodyId>,
+ panic_span: Option<Span>,
) {
if !cx.access_levels.is_exported(hir_id) {
return; // Private functions do not require doc comments
"unsafe function's docs miss `# Safety` section",
);
}
+ if !headers.panics && panic_span.is_some() {
+ span_lint_and_note(
+ cx,
+ MISSING_PANICS_DOC,
+ span,
+ "docs for function which may panic missing `# Panics` section",
+ panic_span,
+ "first possible panic found here",
+ );
+ }
if !headers.errors {
if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym::result_type) {
span_lint(
if_chain! {
if let Some(body_id) = body_id;
if let Some(future) = cx.tcx.lang_items().future_trait();
- let def_id = cx.tcx.hir().body_owner_def_id(body_id);
- let mir = cx.tcx.optimized_mir(def_id.to_def_id());
- let ret_ty = mir.return_ty();
+ let typeck = cx.tcx.typeck_body(body_id);
+ let body = cx.tcx.hir().body(body_id);
+ let ret_ty = typeck.expr_ty(&body.value);
if implements_trait(cx, ret_ty, future, &[]);
if let ty::Opaque(_, subs) = ret_ty.kind();
if let Some(gen) = subs.types().next();
let mut no_stars = String::with_capacity(doc.len());
for line in doc.lines() {
let mut chars = line.chars();
- while let Some(c) = chars.next() {
+ for c in &mut chars {
if c.is_whitespace() {
no_stars.push(c);
} else {
struct DocHeaders {
safety: bool,
errors: bool,
+ panics: bool,
}
fn check_attrs<'a>(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &'a [Attribute]) -> DocHeaders {
return DocHeaders {
safety: true,
errors: true,
+ panics: true,
};
}
}
return DocHeaders {
safety: false,
errors: false,
+ panics: false,
};
}
let mut headers = DocHeaders {
safety: false,
errors: false,
+ panics: false,
};
let mut in_code = false;
let mut in_link = None;
}
headers.safety |= in_heading && text.trim() == "Safety";
headers.errors |= in_heading && text.trim() == "Errors";
+ headers.panics |= in_heading && text.trim() == "Panics";
let index = match spans.binary_search_by(|c| c.0.cmp(&range.start)) {
Ok(o) => o,
Err(e) => e - 1,
| ItemKind::ExternCrate(..)
| ItemKind::ForeignMod(..) => return false,
// We found a main function ...
- ItemKind::Fn(box FnKind(_, sig, _, Some(block)))
- if item.ident.name == sym::main =>
- {
+ ItemKind::Fn(box FnKind(_, sig, _, Some(block))) if item.ident.name == sym::main => {
let is_async = matches!(sig.header.asyncness, Async::Yes { .. });
let returns_nothing = match &sig.decl.output {
FnRetTy::Default(..) => true,
FnRetTy::Ty(ty) if ty.kind.is_unit() => true,
- _ => false,
+ FnRetTy::Ty(_) => false,
};
if returns_nothing && !is_async && !block.stmts.is_empty() {
);
}
}
+
+struct FindPanicUnwrap<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ panic_span: Option<Span>,
+ typeck_results: &'tcx ty::TypeckResults<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if self.panic_span.is_some() {
+ return;
+ }
+
+ // check for `begin_panic`
+ if_chain! {
+ if let ExprKind::Call(func_expr, _) = expr.kind;
+ if let ExprKind::Path(QPath::Resolved(_, path)) = func_expr.kind;
+ if let Some(path_def_id) = path.res.opt_def_id();
+ if match_panic_def_id(self.cx, path_def_id);
+ if is_expn_of(expr.span, "unreachable").is_none();
+ if !is_expn_of_debug_assertions(expr.span);
+ then {
+ self.panic_span = Some(expr.span);
+ }
+ }
+
+ // check for `assert_eq` or `assert_ne`
+ if is_expn_of(expr.span, "assert_eq").is_some() || is_expn_of(expr.span, "assert_ne").is_some() {
+ self.panic_span = Some(expr.span);
+ }
+
+ // check for `unwrap`
+ if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
+ let reciever_ty = self.typeck_results.expr_ty(&arglists[0][0]).peel_refs();
+ if is_type_diagnostic_item(self.cx, reciever_ty, sym::option_type)
+ || is_type_diagnostic_item(self.cx, reciever_ty, sym::result_type)
+ {
+ self.panic_span = Some(expr.span);
+ }
+ }
+
+ // and check sub-expressions
+ intravisit::walk_expr(self, expr);
+ }
+
+ // Panics in const blocks will cause compilation to fail.
+ fn visit_anon_const(&mut self, _: &'tcx AnonConst) {}
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
+ NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
+ }
+}
+
+fn is_expn_of_debug_assertions(span: Span) -> bool {
+ const MACRO_NAMES: &[&str] = &["debug_assert", "debug_assert_eq", "debug_assert_ne"];
+ MACRO_NAMES.iter().any(|name| is_expn_of(span, name).is_some())
+}
projects / rust.git / blobdiff