lint if a private item has doctests

7 files changed, 158 insertions, 43 deletions

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 01d87bdbf63..22f2023eefb 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -319,6 +319,12 @@ declare_lint! {
 }
 
 declare_lint! {
+    pub PRIVATE_DOC_TESTS,
+    Allow,
+    "warn about doc test in private item"
+}
+
+declare_lint! {
     pub WHERE_CLAUSES_OBJECT_SAFETY,
     Warn,
     "checks the object safety of where clauses"
@@ -415,6 +421,7 @@ impl LintPass for HardwiredLints {
             DUPLICATE_MACRO_EXPORTS,
             INTRA_DOC_LINK_RESOLUTION_FAILURE,
             MISSING_DOC_CODE_EXAMPLES,
+            PRIVATE_DOC_TESTS,
             WHERE_CLAUSES_OBJECT_SAFETY,
             PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
             MACRO_USE_EXTERN_CRATE,
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 0bd6f6bf8a2..aac0f9f94e3 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -351,13 +351,15 @@ pub fn run_core(options: RustdocOptions) -> (clean::Crate, RenderInfo, RenderOpt
     let warnings_lint_name = lint::builtin::WARNINGS.name;
     let missing_docs = rustc_lint::builtin::MISSING_DOCS.name;
     let missing_doc_example = rustc_lint::builtin::MISSING_DOC_CODE_EXAMPLES.name;
+    let private_doc_tests = rustc_lint::builtin::PRIVATE_DOC_TESTS.name;
 
     // In addition to those specific lints, we also need to whitelist those given through
     // command line, otherwise they'll get ignored and we don't want that.
     let mut whitelisted_lints = vec![warnings_lint_name.to_owned(),
                                      intra_link_resolution_failure_name.to_owned(),
                                      missing_docs.to_owned(),
-                                     missing_doc_example.to_owned()];
+                                     missing_doc_example.to_owned(),
+                                     private_doc_tests.to_owned()];
 
     whitelisted_lints.extend(lint_opts.iter().map(|(lint, _)| lint).cloned());
 
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 471ba6345e2..675e3e9be1e 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -24,9 +24,9 @@ use std::ops::Range;
 
 use core::DocContext;
 use fold::DocFolder;
-use html::markdown::{find_testable_code, markdown_links, ErrorCodes, LangString};
+use html::markdown::markdown_links;
 
-use passes::Pass;
+use passes::{look_for_tests, Pass};
 
 pub const COLLECT_INTRA_DOC_LINKS: Pass =
     Pass::early("collect-intra-doc-links", collect_intra_doc_links,
@@ -214,43 +214,6 @@ impl<'a, 'tcx, 'rcx, 'cstore> LinkCollector<'a, 'tcx, 'rcx, 'cstore> {
     }
 }
 
-fn look_for_tests<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx>(
-    cx: &'a DocContext<'a, 'tcx, 'rcx, 'cstore>,
-    dox: &str,
-    item: &Item,
-) {
-    if (item.is_mod() && cx.tcx.hir.as_local_node_id(item.def_id).is_none()) ||
-       cx.as_local_node_id(item.def_id).is_none() {
-        // If non-local, no need to check anything.
-        return;
-    }
-
-    struct Tests {
-        found_tests: usize,
-    }
-
-    impl ::test::Tester for Tests {
-        fn add_test(&mut self, _: String, _: LangString, _: usize) {
-            self.found_tests += 1;
-        }
-    }
-
-    let mut tests = Tests {
-        found_tests: 0,
-    };
-
-    if find_testable_code(&dox, &mut tests, ErrorCodes::No).is_ok() {
-        if tests.found_tests == 0 {
-            let mut diag = cx.tcx.struct_span_lint_node(
-                lint::builtin::MISSING_DOC_CODE_EXAMPLES,
-                NodeId::from_u32(0),
-                span_of_attrs(&item.attrs),
-                "Missing code example in this documentation");
-            diag.emit();
-        }
-    }
-}
-
 impl<'a, 'tcx, 'rcx, 'cstore> DocFolder for LinkCollector<'a, 'tcx, 'rcx, 'cstore> {
     fn fold_item(&mut self, mut item: Item) -> Option<Item> {
         let item_node_id = if item.is_mod() {
@@ -313,7 +276,7 @@ impl<'a, 'tcx, 'rcx, 'cstore> DocFolder for LinkCollector<'a, 'tcx, 'rcx, 'cstor
         let cx = self.cx;
         let dox = item.attrs.collapsed_doc_value().unwrap_or_else(String::new);
 
-        look_for_tests(&cx, &dox, &item);
+        look_for_tests(&cx, &dox, &item, true);
 
         if !self.is_nightly_build {
             return None;
@@ -488,7 +451,7 @@ fn macro_resolve(cx: &DocContext, path_str: &str) -> Option<Def> {
     None
 }
 
-fn span_of_attrs(attrs: &Attributes) -> syntax_pos::Span {
+pub fn span_of_attrs(attrs: &Attributes) -> syntax_pos::Span {
     if attrs.doc_strings.is_empty() {
         return DUMMY_SP;
     }
diff --git a/src/librustdoc/passes/mod.rs b/src/librustdoc/passes/mod.rs
index d00eb3257d4..eee7278e4f0 100644
--- a/src/librustdoc/passes/mod.rs
+++ b/src/librustdoc/passes/mod.rs
@@ -12,16 +12,22 @@
 //! process.
 
 use rustc::hir::def_id::DefId;
+use rustc::lint as lint;
 use rustc::middle::privacy::AccessLevels;
 use rustc::util::nodemap::DefIdSet;
 use std::mem;
 use std::fmt;
+use syntax::ast::NodeId;
 
 use clean::{self, GetDefId, Item};
-use core::DocContext;
+use core::{DocContext, DocAccessLevels};
 use fold;
 use fold::StripItem;
 
+use html::markdown::{find_testable_code, ErrorCodes, LangString};
+
+use self::collect_intra_doc_links::span_of_attrs;
+
 mod collapse_docs;
 pub use self::collapse_docs::COLLAPSE_DOCS;
 
@@ -43,6 +49,9 @@ 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 collect_trait_impls;
 pub use self::collect_trait_impls::COLLECT_TRAIT_IMPLS;
 
@@ -128,6 +137,7 @@ impl Pass {
 
 /// The full list of passes.
 pub const PASSES: &'static [Pass] = &[
+    CHECK_PRIVATE_ITEMS_DOC_TESTS,
     STRIP_HIDDEN,
     UNINDENT_COMMENTS,
     COLLAPSE_DOCS,
@@ -141,6 +151,7 @@ pub const PASSES: &'static [Pass] = &[
 /// The list of passes run by default.
 pub const DEFAULT_PASSES: &'static [&'static str] = &[
     "collect-trait-impls",
+    "check-private-items-doc-tests",
     "strip-hidden",
     "strip-private",
     "collect-intra-doc-links",
@@ -152,6 +163,7 @@ pub const DEFAULT_PASSES: &'static [&'static str] = &[
 /// The list of default passes run with `--document-private-items` is passed to rustdoc.
 pub const DEFAULT_PRIVATE_PASSES: &'static [&'static str] = &[
     "collect-trait-impls",
+    "check-private-items-doc-tests",
     "strip-priv-imports",
     "collect-intra-doc-links",
     "collapse-docs",
@@ -348,3 +360,49 @@ impl fold::DocFolder for ImportStripper {
         }
     }
 }
+
+pub fn look_for_tests<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx>(
+    cx: &'a DocContext<'a, 'tcx, 'rcx, 'cstore>,
+    dox: &str,
+    item: &Item,
+    check_missing_code: bool,
+) {
+    if cx.as_local_node_id(item.def_id).is_none() {
+        // If non-local, no need to check anything.
+        return;
+    }
+
+    struct Tests {
+        found_tests: usize,
+    }
+
+    impl ::test::Tester for Tests {
+        fn add_test(&mut self, _: String, _: LangString, _: usize) {
+            self.found_tests += 1;
+        }
+    }
+
+    let mut tests = Tests {
+        found_tests: 0,
+    };
+
+    if find_testable_code(&dox, &mut tests, ErrorCodes::No).is_ok() {
+        if check_missing_code == true && tests.found_tests == 0 {
+            let mut diag = cx.tcx.struct_span_lint_node(
+                lint::builtin::MISSING_DOC_CODE_EXAMPLES,
+                NodeId::from_u32(0),
+                span_of_attrs(&item.attrs),
+                "Missing code example in this documentation");
+            diag.emit();
+        } else if check_missing_code == false &&
+                  tests.found_tests > 0 &&
+                  !cx.renderinfo.borrow().access_levels.is_doc_reachable(item.def_id) {
+            let mut diag = cx.tcx.struct_span_lint_node(
+                lint::builtin::PRIVATE_DOC_TESTS,
+                NodeId::from_u32(0),
+                span_of_attrs(&item.attrs),
+                "Documentation test in private item");
+            diag.emit();
+        }
+    }
+}
diff --git a/src/librustdoc/passes/private_items_doc_tests.rs b/src/librustdoc/passes/private_items_doc_tests.rs
new file mode 100644
index 00000000000..7c5ce8894b1
--- /dev/null
+++ b/src/librustdoc/passes/private_items_doc_tests.rs
@@ -0,0 +1,49 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use clean::*;
+
+use core::DocContext;
+use fold::DocFolder;
+
+use passes::{look_for_tests, Pass};
+
+pub const CHECK_PRIVATE_ITEMS_DOC_TESTS: Pass =
+    Pass::early("check-private-items-doc-tests", check_private_items_doc_tests,
+                "check private items doc tests");
+
+struct PrivateItemDocTestLinter<'a, 'tcx: 'a, 'rcx: 'a, 'cstore: 'rcx> {
+    cx: &'a DocContext<'a, 'tcx, 'rcx, 'cstore>,
+}
+
+impl<'a, 'tcx, 'rcx, 'cstore> PrivateItemDocTestLinter<'a, 'tcx, 'rcx, 'cstore> {
+    fn new(cx: &'a DocContext<'a, 'tcx, 'rcx, 'cstore>) -> 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, 'rcx, 'cstore> DocFolder for PrivateItemDocTestLinter<'a, 'tcx, 'rcx, 'cstore> {
+    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/private-item-doc-test.rs b/src/test/rustdoc-ui/private-item-doc-test.rs
new file mode 100644
index 00000000000..5a13fe359f5
--- /dev/null
+++ b/src/test/rustdoc-ui/private-item-doc-test.rs
@@ -0,0 +1,20 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(private_doc_tests)]
+
+mod foo {
+    /// private doc test
+    ///
+    /// ```
+    /// assert!(false);
+    /// ```
+    fn bar() {}
+}
diff --git a/src/test/rustdoc-ui/private-item-doc-test.stderr b/src/test/rustdoc-ui/private-item-doc-test.stderr
new file mode 100644
index 00000000000..b43add7ea50
--- /dev/null
+++ b/src/test/rustdoc-ui/private-item-doc-test.stderr
@@ -0,0 +1,16 @@
+error: Documentation test in private item
+  --> $DIR/private-item-doc-test.rs:14:5
+   |
+LL | /     /// private doc test
+LL | |     ///
+LL | |     /// ```
+LL | |     /// assert!(false);
+LL | |     /// ```
+   | |___________^
+   |
+note: lint level defined here
+  --> $DIR/private-item-doc-test.rs:11:9
+   |
+LL | #![deny(private_doc_tests)]
+   |         ^^^^^^^^^^^^^^^^^
+