Revert def_id addition from clean::Function, add test for

scrape-examples options

src/doc/rustdoc/src/unstable-features.md

@@ -458,7 +458,13 @@ Calculating code examples follows these rules:
 
 ### `--with-examples`: include examples of uses of items as documentation
 
-This option, combined with `--scrape-examples-target-crate` and `--scrape-examples-output-path`, is used to implement the functionality in [RFC #3123](https://github.com/rust-lang/rfcs/pull/3123). Uses of an item (currently functions / call-sites) are found in a crate and its reverse-dependencies, and then the uses are included as documentation for that item. This feature is intended to be used via `cargo doc --scrape-examples`, but the rustdoc-only workflow looks like:
+This option, combined with `--scrape-examples-target-crate` and
+`--scrape-examples-output-path`, is used to implement the functionality in [RFC
+#3123](https://github.com/rust-lang/rfcs/pull/3123). Uses of an item (currently
+functions / call-sites) are found in a crate and its reverse-dependencies, and
+then the uses are included as documentation for that item. This feature is
+intended to be used via `cargo doc --scrape-examples`, but the rustdoc-only
+workflow looks like:
 
 ```bash
 $ rustdoc examples/ex.rs -Z unstable-options \
@@ -468,4 +474,8 @@ $ rustdoc examples/ex.rs -Z unstable-options \
 $ rustdoc src/lib.rs -Z unstable-options --with-examples output.calls
 ```
 
-First, the library must be checked to generate an `rmeta`. Then a reverse-dependency like `examples/ex.rs` is given to rustdoc with the target crate being documented (`foobar`) and a path to output the calls (`output.calls`). Then, the generated calls file can be passed via `--with-examples` to the subsequent documentation of `foobar`.
+First, the library must be checked to generate an `rmeta`. Then a
+reverse-dependency like `examples/ex.rs` is given to rustdoc with the target
+crate being documented (`foobar`) and a path to output the calls
+(`output.calls`). Then, the generated calls file can be passed via
+`--with-examples` to the subsequent documentation of `foobar`.

src/librustdoc/clean/inline.rs

@@ -235,7 +235,6 @@ fn build_external_function(cx: &mut DocContext<'_>, did: DefId) -> clean::Functi
         decl,
         generics,
         header: hir::FnHeader { unsafety: sig.unsafety(), abi: sig.abi(), constness, asyncness },
-        def_id: did,
     }
 }
 

src/librustdoc/clean/mod.rs

@@ -801,8 +801,7 @@ impl<'a> Clean<Function> for (&'a hir::FnSig<'a>, &'a hir::Generics<'a>, hir::Bo
     fn clean(&self, cx: &mut DocContext<'_>) -> Function {
         let (generics, decl) =
             enter_impl_trait(cx, |cx| (self.1.clean(cx), (&*self.0.decl, self.2).clean(cx)));
-        let def_id = self.2.hir_id.owner.to_def_id();
-        Function { decl, generics, header: self.0.header, def_id }
+        Function { decl, generics, header: self.0.header }
     }
 }
 
@@ -934,8 +933,7 @@ impl Clean<Item> for hir::TraitItem<'_> {
                     let (generics, decl) = enter_impl_trait(cx, |cx| {
                         (self.generics.clean(cx), (&*sig.decl, &names[..]).clean(cx))
                     });
-                    let def_id = self.def_id.to_def_id();
-                    let mut t = Function { header: sig.header, decl, generics, def_id };
+                    let mut t = Function { header: sig.header, decl, generics };
                     if t.header.constness == hir::Constness::Const
                         && is_unstable_const_fn(cx.tcx, local_did).is_some()
                     {
@@ -1069,7 +1067,6 @@ impl Clean<Item> for ty::AssocItem {
                                 constness,
                                 asyncness,
                             },
-                            def_id: self.def_id,
                         },
                         defaultness,
                     )
@@ -1083,7 +1080,6 @@ impl Clean<Item> for ty::AssocItem {
                             constness: hir::Constness::NotConst,
                             asyncness: hir::IsAsync::NotAsync,
                         },
-                        def_id: self.def_id,
                     })
                 }
             }
@@ -2103,7 +2099,6 @@ impl Clean<Item> for (&hir::ForeignItem<'_>, Option<Symbol>) {
                             constness: hir::Constness::NotConst,
                             asyncness: hir::IsAsync::NotAsync,
                         },
-                        def_id,
                     })
                 }
                 hir::ForeignItemKind::Static(ref ty, mutability) => {

src/librustdoc/clean/types.rs

@@ -1254,7 +1254,6 @@ crate struct Function {
     crate decl: FnDecl,
     crate generics: Generics,
     crate header: hir::FnHeader,
-    crate def_id: DefId,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]

src/librustdoc/html/render/mod.rs

@@ -597,11 +597,10 @@ fn document_full_inner(
         clean::ItemKind::StrippedItem(box kind) | kind => kind,
     };
 
-    match kind {
-        clean::ItemKind::FunctionItem(f) | clean::ItemKind::MethodItem(f, _) => {
-            render_call_locations(w, cx, f.def_id, item);
+    if let clean::ItemKind::FunctionItem(..) | clean::ItemKind::MethodItem(..) = kind {
+        if let Some(def_id) = item.def_id.as_def_id() {
+            render_call_locations(w, cx, def_id, item);
         }
-        _ => {}
     }
 }
 

src/librustdoc/json/conversions.rs

@@ -289,7 +289,7 @@ crate fn from_fn_header(header: &rustc_hir::FnHeader) -> HashSet<Qualifiers> {
 
 impl FromWithTcx<clean::Function> for Function {
     fn from_tcx(function: clean::Function, tcx: TyCtxt<'_>) -> Self {
-        let clean::Function { decl, generics, header, def_id: _ } = function;
+        let clean::Function { decl, generics, header } = function;
         Function {
             decl: decl.into_tcx(tcx),
             generics: generics.into_tcx(tcx),
@@ -530,7 +530,7 @@ crate fn from_function_method(
     has_body: bool,
     tcx: TyCtxt<'_>,
 ) -> Method {
-    let clean::Function { header, decl, generics, def_id: _ } = function;
+    let clean::Function { header, decl, generics } = function;
     Method {
         decl: decl.into_tcx(tcx),
         generics: generics.into_tcx(tcx),

src/test/rustdoc-ui/scrape-examples-wrong-options-1.rs

@@ -0,0 +1 @@
+// compile-flags: -Z unstable-options --scrape-examples-target-crate foobar

src/test/rustdoc-ui/scrape-examples-wrong-options-1.stderr

@@ -0,0 +1,2 @@
+error: must use --scrape-examples-output-path and --scrape-examples-target-crate together
+

src/test/rustdoc-ui/scrape-examples-wrong-options-2.rs

@@ -0,0 +1 @@
+// compile-flags: -Z unstable-options --scrape-examples-output-path ex.calls

src/test/rustdoc-ui/scrape-examples-wrong-options-2.stderr

@@ -0,0 +1,2 @@
+error: must use --scrape-examples-output-path and --scrape-examples-target-crate together
+

src/test/rustdoc-ui/scrape-examples-wrong-options.rs

@@ -1 +0,0 @@
-// compile-flags: --scrape-examples-target-crate foobar

src/test/rustdoc-ui/scrape-examples-wrong-options.stderr

@@ -1,2 +0,0 @@
-error: the `-Z unstable-options` flag must also be passed to enable the flag `scrape-examples-target-crate`
-