Auto merge of #74855 - jyn514:separate-lints, r=Manishearth

Separate `missing_doc_code_examples` from intra-doc links

These two lints have no relation other than both being nightly-only.
This allows stabilizing intra-doc links without stabilizing `missing_doc_code_examples`.

Fixes one of the issues spotted by @ollie27 in https://github.com/rust-lang/rust/pull/74430#issuecomment-664693080.

r? @Manishearth

5 files changed, 113 insertions, 103 deletions

diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 5187839423d..418238181e9 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -23,7 +23,7 @@ use crate::clean::*;
 use crate::core::DocContext;
 use crate::fold::DocFolder;
 use crate::html::markdown::markdown_links;
-use crate::passes::{look_for_tests, Pass};
+use crate::passes::Pass;
 
 use super::span_of_attrs;
 
@@ -508,8 +508,6 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
         let dox = item.attrs.collapsed_doc_value().unwrap_or_else(String::new);
         trace!("got documentation '{}'", dox);
 
-        look_for_tests(&cx, &dox, &item, true);
-
         // find item's parent to resolve `Self` in item's docs below
         let parent_name = self.cx.as_local_hir_id(item.def_id).and_then(|item_hir| {
             let parent_hir = self.cx.tcx.hir().get_parent_item(item_hir);
diff --git a/src/librustdoc/passes/doc_test_lints.rs b/src/librustdoc/passes/doc_test_lints.rs
new file mode 100644
index 00000000000..aced7d55281
--- /dev/null
+++ b/src/librustdoc/passes/doc_test_lints.rs
@@ -0,0 +1,97 @@
+//! This pass is overloaded and runs two different lints.
+//!
+//! - MISSING_DOC_CODE_EXAMPLES: this looks for public items missing doc-tests
+//! - PRIVATE_DOC_TESTS: this looks for private items with doc-tests.
+
+use super::{span_of_attrs, Pass};
+use crate::clean::*;
+use crate::core::DocContext;
+use crate::fold::DocFolder;
+use crate::html::markdown::{find_testable_code, ErrorCodes, LangString};
+use rustc_session::lint;
+
+pub const CHECK_PRIVATE_ITEMS_DOC_TESTS: Pass = Pass {
+    name: "check-private-items-doc-tests",
+    run: check_private_items_doc_tests,
+    description: "check private items doc tests",
+};
+
+struct PrivateItemDocTestLinter<'a, 'tcx> {
+    cx: &'a DocContext<'tcx>,
+}
+
+impl<'a, 'tcx> PrivateItemDocTestLinter<'a, 'tcx> {
+    fn new(cx: &'a DocContext<'tcx>) -> Self {
+        PrivateItemDocTestLinter { cx }
+    }
+}
+
+pub fn check_private_items_doc_tests(krate: Crate, cx: &DocContext<'_>) -> Crate {
+    let mut coll = PrivateItemDocTestLinter::new(cx);
+
+    coll.fold_crate(krate)
+}
+
+impl<'a, 'tcx> DocFolder for PrivateItemDocTestLinter<'a, 'tcx> {
+    fn fold_item(&mut self, item: Item) -> Option<Item> {
+        let cx = self.cx;
+        let dox = item.attrs.collapsed_doc_value().unwrap_or_else(String::new);
+
+        look_for_tests(&cx, &dox, &item);
+
+        self.fold_item_recur(item)
+    }
+}
+
+pub fn look_for_tests<'tcx>(cx: &DocContext<'tcx>, dox: &str, item: &Item) {
+    let hir_id = match cx.as_local_hir_id(item.def_id) {
+        Some(hir_id) => hir_id,
+        None => {
+            // If non-local, no need to check anything.
+            return;
+        }
+    };
+
+    struct Tests {
+        found_tests: usize,
+    }
+
+    impl crate::test::Tester for Tests {
+        fn add_test(&mut self, _: String, _: LangString, _: usize) {
+            self.found_tests += 1;
+        }
+    }
+
+    let mut tests = Tests { found_tests: 0 };
+
+    find_testable_code(&dox, &mut tests, ErrorCodes::No, false, None);
+
+    if tests.found_tests == 0 {
+        use ItemEnum::*;
+
+        let should_report = match item.inner {
+            ExternCrateItem(_, _) | ImportItem(_) | PrimitiveItem(_) | KeywordItem(_) => false,
+            _ => true,
+        };
+        if should_report {
+            debug!("reporting error for {:?} (hir_id={:?})", item, hir_id);
+            let sp = span_of_attrs(&item.attrs).unwrap_or(item.source.span());
+            cx.tcx.struct_span_lint_hir(
+                lint::builtin::MISSING_DOC_CODE_EXAMPLES,
+                hir_id,
+                sp,
+                |lint| lint.build("missing code example in this documentation").emit(),
+            );
+        }
+    } else if rustc_feature::UnstableFeatures::from_environment().is_nightly_build()
+        && tests.found_tests > 0
+        && !cx.renderinfo.borrow().access_levels.is_public(item.def_id)
+    {
+        cx.tcx.struct_span_lint_hir(
+            lint::builtin::PRIVATE_DOC_TESTS,
+            hir_id,
+            span_of_attrs(&item.attrs).unwrap_or(item.source.span()),
+            |lint| lint.build("documentation test in private item").emit(),
+        );
+    }
+}
diff --git a/src/librustdoc/passes/mod.rs b/src/librustdoc/passes/mod.rs
index 70366c90139..0eebdbd87ed 100644
--- a/src/librustdoc/passes/mod.rs
+++ b/src/librustdoc/passes/mod.rs
@@ -3,7 +3,6 @@
 
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_middle::middle::privacy::AccessLevels;
-use rustc_session::lint;
 use rustc_span::{InnerSpan, Span, DUMMY_SP};
 use std::mem;
 use std::ops::Range;
@@ -12,7 +11,6 @@ use self::Condition::*;
 use crate::clean::{self, GetDefId, Item};
 use crate::core::DocContext;
 use crate::fold::{DocFolder, StripItem};
-use crate::html::markdown::{find_testable_code, ErrorCodes, LangString};
 
 mod collapse_docs;
 pub use self::collapse_docs::COLLAPSE_DOCS;
@@ -35,8 +33,8 @@ pub use self::propagate_doc_cfg::PROPAGATE_DOC_CFG;
 mod collect_intra_doc_links;
 pub use self::collect_intra_doc_links::COLLECT_INTRA_DOC_LINKS;
 
-mod private_items_doc_tests;
-pub use self::private_items_doc_tests::CHECK_PRIVATE_ITEMS_DOC_TESTS;
+mod doc_test_lints;
+pub use self::doc_test_lints::CHECK_PRIVATE_ITEMS_DOC_TESTS;
 
 mod collect_trait_impls;
 pub use self::collect_trait_impls::COLLECT_TRAIT_IMPLS;
@@ -312,52 +310,6 @@ impl DocFolder for ImportStripper {
     }
 }
 
-pub fn look_for_tests<'tcx>(
-    cx: &DocContext<'tcx>,
-    dox: &str,
-    item: &Item,
-    check_missing_code: bool,
-) {
-    let hir_id = match cx.as_local_hir_id(item.def_id) {
-        Some(hir_id) => hir_id,
-        None => {
-            // If non-local, no need to check anything.
-            return;
-        }
-    };
-
-    struct Tests {
-        found_tests: usize,
-    }
-
-    impl crate::test::Tester for Tests {
-        fn add_test(&mut self, _: String, _: LangString, _: usize) {
-            self.found_tests += 1;
-        }
-    }
-
-    let mut tests = Tests { found_tests: 0 };
-
-    find_testable_code(&dox, &mut tests, ErrorCodes::No, false, None);
-
-    if check_missing_code && tests.found_tests == 0 {
-        let sp = span_of_attrs(&item.attrs).unwrap_or(item.source.span());
-        cx.tcx.struct_span_lint_hir(lint::builtin::MISSING_DOC_CODE_EXAMPLES, hir_id, sp, |lint| {
-            lint.build("missing code example in this documentation").emit()
-        });
-    } else if !check_missing_code
-        && tests.found_tests > 0
-        && !cx.renderinfo.borrow().access_levels.is_public(item.def_id)
-    {
-        cx.tcx.struct_span_lint_hir(
-            lint::builtin::PRIVATE_DOC_TESTS,
-            hir_id,
-            span_of_attrs(&item.attrs).unwrap_or(item.source.span()),
-            |lint| lint.build("documentation test in private item").emit(),
-        );
-    }
-}
-
 /// Returns a span encompassing all the given attributes.
 crate fn span_of_attrs(attrs: &clean::Attributes) -> Option<Span> {
     if attrs.doc_strings.is_empty() {
diff --git a/src/librustdoc/passes/private_items_doc_tests.rs b/src/librustdoc/passes/private_items_doc_tests.rs
deleted file mode 100644
index aec5a6bd4e2..00000000000
--- a/src/librustdoc/passes/private_items_doc_tests.rs
+++ /dev/null
@@ -1,37 +0,0 @@
-use crate::clean::*;
-use crate::core::DocContext;
-use crate::fold::DocFolder;
-use crate::passes::{look_for_tests, Pass};
-
-pub const CHECK_PRIVATE_ITEMS_DOC_TESTS: Pass = Pass {
-    name: "check-private-items-doc-tests",
-    run: check_private_items_doc_tests,
-    description: "check private items doc tests",
-};
-
-struct PrivateItemDocTestLinter<'a, 'tcx> {
-    cx: &'a DocContext<'tcx>,
-}
-
-impl<'a, 'tcx> PrivateItemDocTestLinter<'a, 'tcx> {
-    fn new(cx: &'a DocContext<'tcx>) -> Self {
-        PrivateItemDocTestLinter { cx }
-    }
-}
-
-pub fn check_private_items_doc_tests(krate: Crate, cx: &DocContext<'_>) -> Crate {
-    let mut coll = PrivateItemDocTestLinter::new(cx);
-
-    coll.fold_crate(krate)
-}
-
-impl<'a, 'tcx> DocFolder for PrivateItemDocTestLinter<'a, 'tcx> {
-    fn fold_item(&mut self, item: Item) -> Option<Item> {
-        let cx = self.cx;
-        let dox = item.attrs.collapsed_doc_value().unwrap_or_else(String::new);
-
-        look_for_tests(&cx, &dox, &item, false);
-
-        self.fold_item_recur(item)
-    }
-}
diff --git a/src/test/rustdoc-ui/lint-group.stderr b/src/test/rustdoc-ui/lint-group.stderr
index 14d72e9aad3..ad923c714da 100644
--- a/src/test/rustdoc-ui/lint-group.stderr
+++ b/src/test/rustdoc-ui/lint-group.stderr
@@ -1,3 +1,16 @@
+error: missing code example in this documentation
+  --> $DIR/lint-group.rs:16:1
+   |
+LL | /// wait, this doesn't have a doctest?
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/lint-group.rs:7:9
+   |
+LL | #![deny(rustdoc)]
+   |         ^^^^^^^
+   = note: `#[deny(missing_doc_code_examples)]` implied by `#[deny(rustdoc)]`
+
 error: documentation test in private item
   --> $DIR/lint-group.rs:19:1
    |
@@ -29,18 +42,5 @@ LL | #![deny(rustdoc)]
    = note: `#[deny(intra_doc_link_resolution_failure)]` implied by `#[deny(rustdoc)]`
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
 
-error: missing code example in this documentation
-  --> $DIR/lint-group.rs:16:1
-   |
-LL | /// wait, this doesn't have a doctest?
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: the lint level is defined here
-  --> $DIR/lint-group.rs:7:9
-   |
-LL | #![deny(rustdoc)]
-   |         ^^^^^^^
-   = note: `#[deny(missing_doc_code_examples)]` implied by `#[deny(rustdoc)]`
-
 error: aborting due to 3 previous errors