]> git.lizzy.rs Git - rust.git/blobdiff - src/librustc/lint.rs
Rollup merge of #68342 - lcnr:type_name_docs, r=Dylan-DPC
[rust.git] / src / librustc / lint.rs
index b85982ac3ffce1b388441b1b14c847b5493f3750..2ed6cd5283b10c3ab3e9dc96412d63ecb0031eae 100644 (file)
@@ -1,30 +1,15 @@
 use std::cmp;
 
 use crate::ich::StableHashingContext;
-use crate::lint::context::CheckLintNameResult;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
-use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, DiagnosticId};
+use rustc_errors::{pluralize, Applicability, DiagnosticBuilder, DiagnosticId};
 use rustc_hir::HirId;
 pub use rustc_session::lint::{builtin, Level, Lint, LintId, LintPass};
 use rustc_session::{DiagnosticMessageId, Session};
 use rustc_span::hygiene::MacroKind;
 use rustc_span::source_map::{DesugaringKind, ExpnKind, MultiSpan};
-use rustc_span::symbol::{sym, Symbol};
-use rustc_span::Span;
-use syntax::ast;
-use syntax::attr;
-use syntax::print::pprust;
-use syntax::sess::feature_err;
-
-use rustc_error_codes::*;
-
-mod context;
-mod passes;
-
-pub use context::add_elided_lifetime_in_path_suggestion;
-pub use context::{EarlyContext, LateContext, LintContext, LintStore};
-pub use passes::{EarlyLintPass, EarlyLintPassObject, LateLintPass, LateLintPassObject};
+use rustc_span::{Span, Symbol};
 
 /// How a lint level was set.
 #[derive(Clone, Copy, PartialEq, Eq, HashStable)]
@@ -43,11 +28,11 @@ pub enum LintSource {
 pub type LevelSource = (Level, LintSource);
 
 pub struct LintLevelSets {
-    list: Vec<LintSet>,
-    lint_cap: Level,
+    pub list: Vec<LintSet>,
+    pub lint_cap: Level,
 }
 
-enum LintSet {
+pub enum LintSet {
     CommandLine {
         // -A,-W,-D flags, a `Symbol` for the flag itself and `Level` for which
         // flag.
@@ -133,381 +118,9 @@ pub fn get_lint_id_level(
     }
 }
 
-pub struct LintLevelsBuilder<'a> {
-    sess: &'a Session,
-    sets: LintLevelSets,
-    id_to_set: FxHashMap<HirId, u32>,
-    cur: u32,
-    warn_about_weird_lints: bool,
-}
-
-pub struct BuilderPush {
-    prev: u32,
-    pub changed: bool,
-}
-
-impl<'a> LintLevelsBuilder<'a> {
-    pub fn new(sess: &'a Session, warn_about_weird_lints: bool, store: &LintStore) -> Self {
-        let mut builder = LintLevelsBuilder {
-            sess,
-            sets: LintLevelSets::new(),
-            cur: 0,
-            id_to_set: Default::default(),
-            warn_about_weird_lints,
-        };
-        builder.process_command_line(sess, store);
-        assert_eq!(builder.sets.list.len(), 1);
-        builder
-    }
-
-    fn process_command_line(&mut self, sess: &Session, store: &LintStore) {
-        let mut specs = FxHashMap::default();
-        self.sets.lint_cap = sess.opts.lint_cap.unwrap_or(Level::Forbid);
-
-        for &(ref lint_name, level) in &sess.opts.lint_opts {
-            store.check_lint_name_cmdline(sess, &lint_name, level);
-
-            // If the cap is less than this specified level, e.g., if we've got
-            // `--cap-lints allow` but we've also got `-D foo` then we ignore
-            // this specification as the lint cap will set it to allow anyway.
-            let level = cmp::min(level, self.sets.lint_cap);
-
-            let lint_flag_val = Symbol::intern(lint_name);
-            let ids = match store.find_lints(&lint_name) {
-                Ok(ids) => ids,
-                Err(_) => continue, // errors handled in check_lint_name_cmdline above
-            };
-            for id in ids {
-                let src = LintSource::CommandLine(lint_flag_val);
-                specs.insert(id, (level, src));
-            }
-        }
-
-        self.sets.list.push(LintSet::CommandLine { specs });
-    }
-
-    /// Pushes a list of AST lint attributes onto this context.
-    ///
-    /// This function will return a `BuilderPush` object which should be passed
-    /// to `pop` when this scope for the attributes provided is exited.
-    ///
-    /// This function will perform a number of tasks:
-    ///
-    /// * It'll validate all lint-related attributes in `attrs`
-    /// * It'll mark all lint-related attributes as used
-    /// * Lint levels will be updated based on the attributes provided
-    /// * Lint attributes are validated, e.g., a #[forbid] can't be switched to
-    ///   #[allow]
-    ///
-    /// Don't forget to call `pop`!
-    pub fn push(&mut self, attrs: &[ast::Attribute], store: &LintStore) -> BuilderPush {
-        let mut specs = FxHashMap::default();
-        let sess = self.sess;
-        let bad_attr = |span| struct_span_err!(sess, span, E0452, "malformed lint attribute input");
-        for attr in attrs {
-            let level = match Level::from_symbol(attr.name_or_empty()) {
-                None => continue,
-                Some(lvl) => lvl,
-            };
-
-            let meta = unwrap_or!(attr.meta(), continue);
-            attr::mark_used(attr);
-
-            let mut metas = unwrap_or!(meta.meta_item_list(), continue);
-
-            if metas.is_empty() {
-                // FIXME (#55112): issue unused-attributes lint for `#[level()]`
-                continue;
-            }
-
-            // Before processing the lint names, look for a reason (RFC 2383)
-            // at the end.
-            let mut reason = None;
-            let tail_li = &metas[metas.len() - 1];
-            if let Some(item) = tail_li.meta_item() {
-                match item.kind {
-                    ast::MetaItemKind::Word => {} // actual lint names handled later
-                    ast::MetaItemKind::NameValue(ref name_value) => {
-                        if item.path == sym::reason {
-                            // found reason, reslice meta list to exclude it
-                            metas = &metas[0..metas.len() - 1];
-                            // FIXME (#55112): issue unused-attributes lint if we thereby
-                            // don't have any lint names (`#[level(reason = "foo")]`)
-                            if let ast::LitKind::Str(rationale, _) = name_value.kind {
-                                if !self.sess.features_untracked().lint_reasons {
-                                    feature_err(
-                                        &self.sess.parse_sess,
-                                        sym::lint_reasons,
-                                        item.span,
-                                        "lint reasons are experimental",
-                                    )
-                                    .emit();
-                                }
-                                reason = Some(rationale);
-                            } else {
-                                bad_attr(name_value.span)
-                                    .span_label(name_value.span, "reason must be a string literal")
-                                    .emit();
-                            }
-                        } else {
-                            bad_attr(item.span)
-                                .span_label(item.span, "bad attribute argument")
-                                .emit();
-                        }
-                    }
-                    ast::MetaItemKind::List(_) => {
-                        bad_attr(item.span).span_label(item.span, "bad attribute argument").emit();
-                    }
-                }
-            }
-
-            for li in metas {
-                let meta_item = match li.meta_item() {
-                    Some(meta_item) if meta_item.is_word() => meta_item,
-                    _ => {
-                        let sp = li.span();
-                        let mut err = bad_attr(sp);
-                        let mut add_label = true;
-                        if let Some(item) = li.meta_item() {
-                            if let ast::MetaItemKind::NameValue(_) = item.kind {
-                                if item.path == sym::reason {
-                                    err.span_label(sp, "reason in lint attribute must come last");
-                                    add_label = false;
-                                }
-                            }
-                        }
-                        if add_label {
-                            err.span_label(sp, "bad attribute argument");
-                        }
-                        err.emit();
-                        continue;
-                    }
-                };
-                let tool_name = if meta_item.path.segments.len() > 1 {
-                    let tool_ident = meta_item.path.segments[0].ident;
-                    if !attr::is_known_lint_tool(tool_ident) {
-                        struct_span_err!(
-                            sess,
-                            tool_ident.span,
-                            E0710,
-                            "an unknown tool name found in scoped lint: `{}`",
-                            pprust::path_to_string(&meta_item.path),
-                        )
-                        .emit();
-                        continue;
-                    }
-
-                    Some(tool_ident.name)
-                } else {
-                    None
-                };
-                let name = meta_item.path.segments.last().expect("empty lint name").ident.name;
-                match store.check_lint_name(&name.as_str(), tool_name) {
-                    CheckLintNameResult::Ok(ids) => {
-                        let src = LintSource::Node(name, li.span(), reason);
-                        for id in ids {
-                            specs.insert(*id, (level, src));
-                        }
-                    }
-
-                    CheckLintNameResult::Tool(result) => {
-                        match result {
-                            Ok(ids) => {
-                                let complete_name = &format!("{}::{}", tool_name.unwrap(), name);
-                                let src = LintSource::Node(
-                                    Symbol::intern(complete_name),
-                                    li.span(),
-                                    reason,
-                                );
-                                for id in ids {
-                                    specs.insert(*id, (level, src));
-                                }
-                            }
-                            Err((Some(ids), new_lint_name)) => {
-                                let lint = builtin::RENAMED_AND_REMOVED_LINTS;
-                                let (lvl, src) =
-                                    self.sets.get_lint_level(lint, self.cur, Some(&specs), &sess);
-                                let msg = format!(
-                                    "lint name `{}` is deprecated \
-                                     and may not have an effect in the future. \
-                                     Also `cfg_attr(cargo-clippy)` won't be necessary anymore",
-                                    name
-                                );
-                                struct_lint_level(
-                                    self.sess,
-                                    lint,
-                                    lvl,
-                                    src,
-                                    Some(li.span().into()),
-                                    &msg,
-                                )
-                                .span_suggestion(
-                                    li.span(),
-                                    "change it to",
-                                    new_lint_name.to_string(),
-                                    Applicability::MachineApplicable,
-                                )
-                                .emit();
-
-                                let src = LintSource::Node(
-                                    Symbol::intern(&new_lint_name),
-                                    li.span(),
-                                    reason,
-                                );
-                                for id in ids {
-                                    specs.insert(*id, (level, src));
-                                }
-                            }
-                            Err((None, _)) => {
-                                // If Tool(Err(None, _)) is returned, then either the lint does not
-                                // exist in the tool or the code was not compiled with the tool and
-                                // therefore the lint was never added to the `LintStore`. To detect
-                                // this is the responsibility of the lint tool.
-                            }
-                        }
-                    }
-
-                    _ if !self.warn_about_weird_lints => {}
-
-                    CheckLintNameResult::Warning(msg, renamed) => {
-                        let lint = builtin::RENAMED_AND_REMOVED_LINTS;
-                        let (level, src) =
-                            self.sets.get_lint_level(lint, self.cur, Some(&specs), &sess);
-                        let mut err = struct_lint_level(
-                            self.sess,
-                            lint,
-                            level,
-                            src,
-                            Some(li.span().into()),
-                            &msg,
-                        );
-                        if let Some(new_name) = renamed {
-                            err.span_suggestion(
-                                li.span(),
-                                "use the new name",
-                                new_name,
-                                Applicability::MachineApplicable,
-                            );
-                        }
-                        err.emit();
-                    }
-                    CheckLintNameResult::NoLint(suggestion) => {
-                        let lint = builtin::UNKNOWN_LINTS;
-                        let (level, src) =
-                            self.sets.get_lint_level(lint, self.cur, Some(&specs), self.sess);
-                        let msg = format!("unknown lint: `{}`", name);
-                        let mut db = struct_lint_level(
-                            self.sess,
-                            lint,
-                            level,
-                            src,
-                            Some(li.span().into()),
-                            &msg,
-                        );
-
-                        if let Some(suggestion) = suggestion {
-                            db.span_suggestion(
-                                li.span(),
-                                "did you mean",
-                                suggestion.to_string(),
-                                Applicability::MachineApplicable,
-                            );
-                        }
-
-                        db.emit();
-                    }
-                }
-            }
-        }
-
-        for (id, &(level, ref src)) in specs.iter() {
-            if level == Level::Forbid {
-                continue;
-            }
-            let forbid_src = match self.sets.get_lint_id_level(*id, self.cur, None) {
-                (Some(Level::Forbid), src) => src,
-                _ => continue,
-            };
-            let forbidden_lint_name = match forbid_src {
-                LintSource::Default => id.to_string(),
-                LintSource::Node(name, _, _) => name.to_string(),
-                LintSource::CommandLine(name) => name.to_string(),
-            };
-            let (lint_attr_name, lint_attr_span) = match *src {
-                LintSource::Node(name, span, _) => (name, span),
-                _ => continue,
-            };
-            let mut diag_builder = struct_span_err!(
-                self.sess,
-                lint_attr_span,
-                E0453,
-                "{}({}) overruled by outer forbid({})",
-                level.as_str(),
-                lint_attr_name,
-                forbidden_lint_name
-            );
-            diag_builder.span_label(lint_attr_span, "overruled by previous forbid");
-            match forbid_src {
-                LintSource::Default => {}
-                LintSource::Node(_, forbid_source_span, reason) => {
-                    diag_builder.span_label(forbid_source_span, "`forbid` level set here");
-                    if let Some(rationale) = reason {
-                        diag_builder.note(&rationale.as_str());
-                    }
-                }
-                LintSource::CommandLine(_) => {
-                    diag_builder.note("`forbid` lint level was set on command line");
-                }
-            }
-            diag_builder.emit();
-            // don't set a separate error for every lint in the group
-            break;
-        }
-
-        let prev = self.cur;
-        if specs.len() > 0 {
-            self.cur = self.sets.list.len() as u32;
-            self.sets.list.push(LintSet::Node { specs: specs, parent: prev });
-        }
-
-        BuilderPush { prev: prev, changed: prev != self.cur }
-    }
-
-    /// Called after `push` when the scope of a set of attributes are exited.
-    pub fn pop(&mut self, push: BuilderPush) {
-        self.cur = push.prev;
-    }
-
-    /// Used to emit a lint-related diagnostic based on the current state of
-    /// this lint context.
-    pub fn struct_lint(
-        &self,
-        lint: &'static Lint,
-        span: Option<MultiSpan>,
-        msg: &str,
-    ) -> DiagnosticBuilder<'a> {
-        let (level, src) = self.sets.get_lint_level(lint, self.cur, None, self.sess);
-        struct_lint_level(self.sess, lint, level, src, span, msg)
-    }
-
-    /// Registers the ID provided with the current set of lints stored in
-    /// this context.
-    pub fn register_id(&mut self, id: HirId) {
-        self.id_to_set.insert(id, self.cur);
-    }
-
-    pub fn build(self) -> LintLevelSets {
-        self.sets
-    }
-
-    pub fn build_map(self) -> LintLevelMap {
-        LintLevelMap { sets: self.sets, id_to_set: self.id_to_set }
-    }
-}
-
 pub struct LintLevelMap {
-    sets: LintLevelSets,
-    id_to_set: FxHashMap<HirId, u32>,
+    pub sets: LintLevelSets,
+    pub id_to_set: FxHashMap<HirId, u32>,
 }
 
 impl LintLevelMap {
@@ -712,3 +325,45 @@ pub fn in_external_macro(sess: &Session, span: Span) -> bool {
         ExpnKind::Macro(..) => true, // definitely a plugin
     }
 }
+
+pub fn add_elided_lifetime_in_path_suggestion(
+    sess: &Session,
+    db: &mut DiagnosticBuilder<'_>,
+    n: usize,
+    path_span: Span,
+    incl_angl_brckt: bool,
+    insertion_span: Span,
+    anon_lts: String,
+) {
+    let (replace_span, suggestion) = if incl_angl_brckt {
+        (insertion_span, anon_lts)
+    } else {
+        // When possible, prefer a suggestion that replaces the whole
+        // `Path<T>` expression with `Path<'_, T>`, rather than inserting `'_, `
+        // at a point (which makes for an ugly/confusing label)
+        if let Ok(snippet) = sess.source_map().span_to_snippet(path_span) {
+            // But our spans can get out of whack due to macros; if the place we think
+            // we want to insert `'_` isn't even within the path expression's span, we
+            // should bail out of making any suggestion rather than panicking on a
+            // subtract-with-overflow or string-slice-out-out-bounds (!)
+            // FIXME: can we do better?
+            if insertion_span.lo().0 < path_span.lo().0 {
+                return;
+            }
+            let insertion_index = (insertion_span.lo().0 - path_span.lo().0) as usize;
+            if insertion_index > snippet.len() {
+                return;
+            }
+            let (before, after) = snippet.split_at(insertion_index);
+            (path_span, format!("{}{}{}", before, anon_lts, after))
+        } else {
+            (insertion_span, anon_lts)
+        }
+    };
+    db.span_suggestion(
+        replace_span,
+        &format!("indicate the anonymous lifetime{}", pluralize!(n)),
+        suggestion,
+        Applicability::MachineApplicable,
+    );
+}