cap-lints when building rustdoc JSON (obi1kenobi#357)

* cap-lints when building rustdoc JSON

* Add `broken_rustdoc` test crate.

* Conditionally disable lints when building rustdoc.

---------

Co-authored-by: Predrag Gruevski <obi1kenobi82@gmail.com>
Co-authored-by: Predrag Gruevski <2348618+obi1kenobi@users.noreply.github.com>

scripts/regenerate_test_rustdocs.sh

@@ -27,7 +27,16 @@ for crate_pair in $(find "$TOPLEVEL/test_crates/" -maxdepth 1 -mindepth 1 -type
                 echo "Generating: $crate"
 
                 pushd "$TOPLEVEL/test_crates/$crate"
-                RUSTC_BOOTSTRAP=1 $RUSTDOC_CMD -- -Zunstable-options --document-private-items --document-hidden-items --output-format=json
+
+                # Determine whether to warn on lints or allow them.
+                CAP_LINTS="warn"
+                if [[ "$crate" == "broken_rustdoc" ]]; then
+                    # This crate *intentionally* has broken rustdoc.
+                    # Don't warn on it. The warnings and errors are thing being tested.
+                    CAP_LINTS="allow"
+                fi
+
+                RUSTC_BOOTSTRAP=1 $RUSTDOC_CMD -- -Zunstable-options --document-private-items --document-hidden-items --cap-lints "$CAP_LINTS" --output-format=json
                 mkdir -p "$TARGET_DIR/$crate"
                 mv "$RUSTDOC_OUTPUT_DIR/$crate_pair.json" "$TARGET_DIR/$crate/rustdoc.json"
                 popd

src/rustdoc_cmd.rs

@@ -65,7 +65,7 @@ impl RustdocCommand {
         cmd.env("RUSTC_BOOTSTRAP", "1")
             .env(
                 "RUSTDOCFLAGS",
-                "-Z unstable-options --document-private-items --document-hidden-items --output-format=json",
+                "-Z unstable-options --document-private-items --document-hidden-items --output-format=json --cap-lints allow",
             )
             .stdout(std::process::Stdio::null()) // Don't pollute output
             .stderr(stderr)

test_crates/broken_rustdoc/new/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+publish = false
+name = "broken_rustdoc"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

test_crates/broken_rustdoc/new/src/lib.rs

@@ -0,0 +1,8 @@
+#![deny(missing_docs, rustdoc::broken_intra_doc_links)]
+
+/// Rust doc comment with an unescaped HTML <tag> that rustdoc will complain about.
+///
+/// Also, a link that points to nowhere: [`Foo::bar`].
+pub struct Foo;
+
+pub struct Undocumented;  // fails the `missing_docs` lint

test_crates/broken_rustdoc/old/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+publish = false
+name = "broken_rustdoc"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

test_crates/broken_rustdoc/old/src/lib.rs

@@ -0,0 +1,8 @@
+#![deny(missing_docs, rustdoc::broken_intra_doc_links)]
+
+/// Rust doc comment with an unescaped HTML <tag> that rustdoc will complain about.
+///
+/// Also, a link that points to nowhere: [`Foo::bar`].
+pub struct Foo;
+
+pub struct Undocumented;  // fails the `missing_docs` lint