rustdoc: Split the pruning of undocumented branches into two passes

prune_undoc_details_pass strips arguments and return values that are
undocumented. prune_undoc_items_pass prunes entire items.

4 files changed, 187 insertions, 104 deletions

diff --git a/src/rustdoc/prune_undoc_details_pass.rs b/src/rustdoc/prune_undoc_details_pass.rs
new file mode 100644
index 00000000000..0dd66ffcdd8
--- /dev/null
+++ b/src/rustdoc/prune_undoc_details_pass.rs
@@ -0,0 +1,162 @@
+#[doc = "Prunes args, retvals of the document tree that \
+         contain no documentation"];
+
+export mk_pass;
+
+fn mk_pass() -> pass {
+    run
+}
+
+fn run(
+    _srv: astsrv::srv,
+    doc: doc::cratedoc
+) -> doc::cratedoc {
+    let fold = fold::fold({
+        fold_fn: fold_fn,
+        fold_res: fold_res,
+        fold_iface: fold_iface,
+        fold_impl: fold_impl
+        with *fold::default_seq_fold(())
+    });
+    fold.fold_crate(fold, doc)
+}
+
+fn fold_fn(
+    fold: fold::fold<()>,
+    doc: doc::fndoc
+) -> doc::fndoc {
+    let doc = fold::default_seq_fold_fn(fold, doc);
+
+    {
+        args: prune_args(doc.args),
+        return: prune_return(doc.return)
+        with doc
+    }
+}
+
+fn prune_args(docs: [doc::argdoc]) -> [doc::argdoc] {
+    vec::filter_map(docs) {|doc|
+        if option::is_some(doc.desc) {
+            some(doc)
+        } else {
+            none
+        }
+    }
+}
+
+fn prune_return(doc: doc::retdoc) -> doc::retdoc {
+    {
+        ty: if option::is_some(doc.desc) {
+            doc.ty
+        } else {
+            none
+        }
+        with doc
+    }
+}
+
+#[test]
+fn should_elide_undocumented_arguments() {
+    let doc = test::mk_doc("#[doc = \"hey\"] fn a(b: int) { }");
+    assert vec::is_empty(doc.topmod.fns()[0].args);
+}
+
+#[test]
+fn should_elide_undocumented_return_values() {
+    let source = "#[doc = \"fonz\"] fn a() -> int { }";
+    let srv = astsrv::mk_srv_from_str(source);
+    let doc = extract::from_srv(srv, "");
+    let doc = tystr_pass::mk_pass()(srv, doc);
+    let doc = attr_pass::mk_pass()(srv, doc);
+    let doc = run(srv, doc);
+    assert doc.topmod.fns()[0].return.ty == none;
+}
+
+fn fold_res(
+    fold: fold::fold<()>,
+    doc: doc::resdoc
+) -> doc::resdoc {
+    let doc = fold::default_seq_fold_res(fold, doc);
+
+    {
+        args: prune_args(doc.args)
+        with doc
+    }
+}
+
+#[test]
+fn should_elide_undocumented_resource_args() {
+    let doc = test::mk_doc("#[doc = \"drunk\"]\
+                            resource r(a: bool) { }");
+    assert vec::is_empty(doc.topmod.resources()[0].args);
+}
+
+fn fold_iface(
+    fold: fold::fold<()>,
+    doc: doc::ifacedoc
+) -> doc::ifacedoc {
+    let doc = fold::default_seq_fold_iface(fold, doc);
+
+    {
+        methods: prune_methods(doc.methods)
+        with doc
+    }
+}
+
+fn prune_methods(docs: [doc::methoddoc]) -> [doc::methoddoc] {
+    vec::map(docs) {|doc|
+        {
+            args: prune_args(doc.args),
+            return: prune_return(doc.return)
+            with doc
+        }
+    }
+}
+
+#[test]
+fn should_elide_undocumented_iface_method_args() {
+    let doc = test::mk_doc("#[doc = \"hey\"] iface i { fn a(); }");
+    assert vec::is_empty(doc.topmod.ifaces()[0].methods[0].args);
+}
+
+#[test]
+fn should_elide_undocumented_iface_method_return_values() {
+    let doc = test::mk_doc("#[doc = \"hey\"] iface i { fn a() -> int; }");
+    assert doc.topmod.ifaces()[0].methods[0].return.ty == none;
+}
+
+fn fold_impl(
+    fold: fold::fold<()>,
+    doc: doc::impldoc
+) -> doc::impldoc {
+    let doc = fold::default_seq_fold_impl(fold, doc);
+
+    {
+        methods: prune_methods(doc.methods)
+        with doc
+    }
+}
+
+#[test]
+fn should_elide_undocumented_impl_method_args() {
+    let doc = test::mk_doc(
+        "#[doc = \"hey\"] impl i for int { fn a(b: bool) { } }");
+    assert vec::is_empty(doc.topmod.impls()[0].methods[0].args);
+}
+
+#[test]
+fn should_elide_undocumented_impl_method_return_values() {
+    let doc = test::mk_doc(
+        "#[doc = \"hey\"] impl i for int { fn a() -> int { } }");
+    assert doc.topmod.impls()[0].methods[0].return.ty == none;
+}
+
+#[cfg(test)]
+mod test {
+    fn mk_doc(source: str) -> doc::cratedoc {
+        let srv = astsrv::mk_srv_from_str(source);
+        let doc = extract::from_srv(srv, "");
+        let doc = attr_pass::mk_pass()(srv, doc);
+        run(srv, doc)
+    }
+}
diff --git a/src/rustdoc/prune_undoc_pass.rs b/src/rustdoc/prune_undoc_items_pass.rs
index 5b197b9859a..3fa3298bdc5 100644
--- a/src/rustdoc/prune_undoc_pass.rs
+++ b/src/rustdoc/prune_undoc_items_pass.rs
@@ -1,4 +1,4 @@
-#[doc = "Prunes branches of the document tree that contain no documentation"];
+#[doc = "Prunes items of the document tree that contain no documentation"];
 
 export mk_pass;
 
@@ -109,46 +109,27 @@ fn fold_fn(
     fold: fold::fold<ctxt>,
     doc: doc::fndoc
 ) -> doc::fndoc {
-    let doc = {
-        args: prune_args(doc.args),
-        return: prune_return(doc.return)
-        with doc
-    };
+    let doc = fold::default_seq_fold_fn(fold, doc);
 
     fold.ctxt.have_docs =
         doc.brief != none
         || doc.desc != none
-        || vec::is_not_empty(doc.args)
+        || args_have_docs(doc.args)
         || doc.return.desc != none
         || doc.failure != none;
     ret doc;
 }
 
-fn prune_args(docs: [doc::argdoc]) -> [doc::argdoc] {
-    vec::filter_map(docs) {|doc|
-        if option::is_some(doc.desc) {
-            some(doc)
-        } else {
-            none
-        }
-    }
-}
-
-fn prune_return(doc: doc::retdoc) -> doc::retdoc {
-    {
-        ty: if option::is_some(doc.desc) {
-            doc.ty
-        } else {
-            none
-        }
-        with doc
+fn args_have_docs(docs: [doc::argdoc]) -> bool {
+    vec::foldl(false, docs) {|accum, doc|
+        accum || doc.desc != none
     }
 }
 
 #[test]
-fn should_elide_undocumented_arguments() {
-    let doc = test::mk_doc("#[doc = \"hey\"] fn a(b: int) { }");
-    assert vec::is_empty(doc.topmod.fns()[0].args);
+fn should_elide_fns_with_undocumented_arguments() {
+    let doc = test::mk_doc("fn a(a: int) { }");
+    assert vec::is_empty(doc.topmod.fns());
 }
 
 #[test]
@@ -158,17 +139,6 @@ fn should_not_elide_fns_with_documented_arguments() {
 }
 
 #[test]
-fn should_elide_undocumented_return_values() {
-    let source = "#[doc = \"fonz\"] fn a() -> int { }";
-    let srv = astsrv::mk_srv_from_str(source);
-    let doc = extract::from_srv(srv, "");
-    let doc = tystr_pass::mk_pass()(srv, doc);
-    let doc = attr_pass::mk_pass()(srv, doc);
-    let doc = run(srv, doc);
-    assert doc.topmod.fns()[0].return.ty == none;
-}
-
-#[test]
 fn should_not_elide_fns_with_documented_failure_conditions() {
     let doc = test::mk_doc("#[doc(failure = \"yup\")] fn a() { }");
     assert vec::is_not_empty(doc.topmod.fns());
@@ -252,20 +222,12 @@ fn should_not_elide_enums_with_documented_variants() {
 }
 
 fn fold_res(fold: fold::fold<ctxt>, doc: doc::resdoc) -> doc::resdoc {
-    let doc = {
-        args: vec::filter_map(doc.args) {|arg|
-            if arg.desc != none {
-                some(arg)
-            } else {
-                none
-            }
-        }
-        with fold::default_seq_fold_res(fold, doc)
-    };
+    let doc = fold::default_seq_fold_res(fold, doc);
+
     fold.ctxt.have_docs =
         doc.brief != none
         || doc.desc != none
-        || vec::is_not_empty(doc.args);
+        || args_have_docs(doc.args);
     ret doc;
 }
 
@@ -276,13 +238,6 @@ fn should_elide_undocumented_resources() {
 }
 
 #[test]
-fn should_elide_undocumented_resource_args() {
-    let doc = test::mk_doc("#[doc = \"drunk\"]\
-                            resource r(a: bool) { }");
-    assert vec::is_empty(doc.topmod.resources()[0].args);
-}
-
-#[test]
 fn should_not_elide_resources_with_documented_args() {
     let doc = test::mk_doc("#[doc(args(a = \"drunk\"))]\
                             resource r(a: bool) { }");
@@ -294,10 +249,7 @@ fn fold_iface(
     doc: doc::ifacedoc
 ) -> doc::ifacedoc {
     let doc = fold::default_seq_fold_iface(fold, doc);
-    let doc = {
-        methods: prune_methods(doc.methods)
-        with doc
-    };
+
     fold.ctxt.have_docs =
         doc.brief != none
         || doc.desc != none
@@ -305,22 +257,12 @@ fn fold_iface(
     ret doc;
 }
 
-fn prune_methods(docs: [doc::methoddoc]) -> [doc::methoddoc] {
-    vec::map(docs) {|doc|
-        {
-            args: prune_args(doc.args),
-            return: prune_return(doc.return)
-            with doc
-        }
-    }
-}
-
 fn methods_have_docs(docs: [doc::methoddoc]) -> bool {
     vec::foldl(false, docs) {|accum, doc|
         accum
             || doc.brief != none
             || doc.desc != none
-            || vec::is_not_empty(doc.args)
+            || args_have_docs(doc.args)
             || doc.return.desc != none
             || doc.failure != none
     }
@@ -339,6 +281,12 @@ fn should_not_elide_documented_ifaces() {
 }
 
 #[test]
+fn should_elide_ifaces_with_undocumented_args() {
+    let doc = test::mk_doc("iface i { fn a(b: bool); }");
+    assert vec::is_empty(doc.topmod.ifaces());
+}
+
+#[test]
 fn should_not_elide_ifaces_with_documented_methods() {
     let doc = test::mk_doc("iface i { #[doc = \"hey\"] fn a(); }");
     assert vec::is_not_empty(doc.topmod.ifaces());
@@ -350,27 +298,12 @@ fn should_not_elide_undocumented_iface_methods() {
     assert vec::is_not_empty(doc.topmod.ifaces()[0].methods);
 }
 
-#[test]
-fn should_elide_undocumented_iface_method_args() {
-    let doc = test::mk_doc("#[doc = \"hey\"] iface i { fn a(); }");
-    assert vec::is_empty(doc.topmod.ifaces()[0].methods[0].args);
-}
-
-#[test]
-fn should_elide_undocumented_iface_method_return_values() {
-    let doc = test::mk_doc("#[doc = \"hey\"] iface i { fn a() -> int; }");
-    assert doc.topmod.ifaces()[0].methods[0].return.ty == none;
-}
-
 fn fold_impl(
     fold: fold::fold<ctxt>,
     doc: doc::impldoc
 ) -> doc::impldoc {
     let doc = fold::default_seq_fold_impl(fold, doc);
-    let doc = {
-        methods: prune_methods(doc.methods)
-        with doc
-    };
+
     fold.ctxt.have_docs =
         doc.brief != none
         || doc.desc != none
@@ -402,20 +335,6 @@ fn should_not_elide_undocumented_impl_methods() {
     assert vec::is_not_empty(doc.topmod.impls()[0].methods);
 }
 
-#[test]
-fn should_elide_undocumented_impl_method_args() {
-    let doc = test::mk_doc(
-        "#[doc = \"hey\"] impl i for int { fn a(b: bool) { } }");
-    assert vec::is_empty(doc.topmod.impls()[0].methods[0].args);
-}
-
-#[test]
-fn should_elide_undocumented_impl_method_return_values() {
-    let doc = test::mk_doc(
-        "#[doc = \"hey\"] impl i for int { fn a() -> int { } }");
-    assert doc.topmod.impls()[0].methods[0].return.ty == none;
-}
-
 #[cfg(test)]
 mod test {
     fn mk_doc(source: str) -> doc::cratedoc {
diff --git a/src/rustdoc/rustdoc.rc b/src/rustdoc/rustdoc.rc
index 6987e7516dc..a8669237368 100644
--- a/src/rustdoc/rustdoc.rc
+++ b/src/rustdoc/rustdoc.rc
@@ -21,7 +21,8 @@ mod fold;
 mod path_pass;
 mod attr_pass;
 mod tystr_pass;
-mod prune_undoc_pass;
+mod prune_undoc_details_pass;
+mod prune_undoc_items_pass;
 mod prune_unexported_pass;
 mod desc_to_brief_pass;
 mod desc_pass;
diff --git a/src/rustdoc/rustdoc.rs b/src/rustdoc/rustdoc.rs
index d309bf56ab6..e117222aedf 100755
--- a/src/rustdoc/rustdoc.rs
+++ b/src/rustdoc/rustdoc.rs
@@ -100,8 +100,9 @@ fn run(source_file: str) {
         tystr_pass::mk_pass(),
         path_pass::mk_pass(),
         attr_pass::mk_pass(),
+        prune_undoc_details_pass::mk_pass(),
         // FIXME: This pass should be optional
-        prune_undoc_pass::mk_pass(),
+        // prune_undoc_items_pass::mk_pass(),
         desc_to_brief_pass::mk_pass(),
         trim_pass::mk_pass(),
         unindent_pass::mk_pass(),