Auto merge of #51611 - QuietMisdreavus:slippery-macros, r=ollie27

rustdoc: import cross-crate macros alongside everything else

The thrilling conclusion of the cross-crate macro saga in rustdoc! After #51425 made sure we saw all the namespaces of an import (and prevented us from losing the `vec!` macro in std's documentation), here is the PR to handle cross-crate macro re-exports at the same time as everything else. This way, attributes like `#[doc(hidden)]` and `#[doc(no_inline)]` can be used to control how the documentation for these macros is seen, rather than rustdoc inlining every macro every time.

Fixes #50647

src/librustdoc/clean/inline.rs

@@ -13,16 +13,19 @@
 use std::iter::once;
 
 use syntax::ast;
-use rustc::hir;
+use syntax::ext::base::MacroKind;
+use syntax_pos::Span;
 
+use rustc::hir;
 use rustc::hir::def::{Def, CtorKind};
 use rustc::hir::def_id::DefId;
+use rustc::middle::cstore::LoadedMacro;
 use rustc::ty;
 use rustc::util::nodemap::FxHashSet;
 
 use core::{DocContext, DocAccessLevels};
 use doctree;
-use clean::{self, GetDefId, get_auto_traits_with_def_id};
+use clean::{self, GetDefId, ToSource, get_auto_traits_with_def_id};
 
 use super::Clean;
 
@@ -97,9 +100,12 @@ pub fn try_inline(cx: &DocContext, def: Def, name: ast::Name, visited: &mut FxHa
             record_extern_fqn(cx, did, clean::TypeKind::Const);
             clean::ConstantItem(build_const(cx, did))
         }
-        // Macros are eagerly inlined back in visit_ast, don't show their export statements
-        // FIXME(50647): the eager inline does not take doc(hidden)/doc(no_inline) into account
-        Def::Macro(..) => return Some(Vec::new()),
+        // FIXME(misdreavus): if attributes/derives come down here we should probably document them
+        // separately
+        Def::Macro(did, MacroKind::Bang) => {
+            record_extern_fqn(cx, did, clean::TypeKind::Macro);
+            clean::MacroItem(build_macro(cx, did, name))
+        }
         _ => return None,
     };
     cx.renderinfo.borrow_mut().inlined.insert(did);
@@ -460,6 +466,33 @@ fn build_static(cx: &DocContext, did: DefId, mutable: bool) -> clean::Static {
     }
 }
 
+fn build_macro(cx: &DocContext, did: DefId, name: ast::Name) -> clean::Macro {
+    let imported_from = cx.tcx.original_crate_name(did.krate);
+    let def = match cx.cstore.load_macro_untracked(did, cx.sess()) {
+        LoadedMacro::MacroDef(macro_def) => macro_def,
+        // FIXME(jseyfried): document proc macro re-exports
+        LoadedMacro::ProcMacro(..) => panic!("attempting to document proc-macro re-export"),
+    };
+
+    let matchers: hir::HirVec<Span> = if let ast::ItemKind::MacroDef(ref def) = def.node {
+        let tts: Vec<_> = def.stream().into_trees().collect();
+        tts.chunks(4).map(|arm| arm[0].span()).collect()
+    } else {
+        unreachable!()
+    };
+
+    let source = format!("macro_rules! {} {{\n{}}}",
+                         name.clean(cx),
+                         matchers.iter().map(|span| {
+                             format!("    {} => {{ ... }};\n", span.to_src(cx))
+                         }).collect::<String>());
+
+    clean::Macro {
+        source,
+        imported_from: Some(imported_from).clean(cx),
+    }
+}
+
 /// A trait's generics clause actually contains all of the predicates for all of
 /// its associated types as well. We specifically move these clauses to the
 /// associated types instead when displaying, so when we're generating the

src/librustdoc/visit_ast.rs

@@ -21,9 +21,8 @@ use syntax_pos::{self, Span};
 use rustc::hir::map as hir_map;
 use rustc::hir::def::Def;
 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
-use rustc::middle::cstore::{LoadedMacro, CrateStore};
+use rustc::middle::cstore::CrateStore;
 use rustc::middle::privacy::AccessLevel;
-use rustc::ty::Visibility;
 use rustc::util::nodemap::{FxHashSet, FxHashMap};
 
 use rustc::hir;
@@ -212,44 +211,6 @@ impl<'a, 'tcx, 'rcx> RustdocVisitor<'a, 'tcx, 'rcx> {
             self.visit_item(item, None, &mut om);
         }
         self.inside_public_path = orig_inside_public_path;
-        let def_id = self.cx.tcx.hir.local_def_id(id);
-        if let Some(exports) = self.cx.tcx.module_exports(def_id) {
-            for export in exports.iter().filter(|e| e.vis == Visibility::Public) {
-                if let Def::Macro(def_id, ..) = export.def {
-                    // FIXME(50647): this eager macro inlining does not take
-                    // doc(hidden)/doc(no_inline) into account
-                    if def_id.krate == LOCAL_CRATE {
-                        continue // These are `krate.exported_macros`, handled in `self.visit()`.
-                    }
-
-                    let imported_from = self.cx.tcx.original_crate_name(def_id.krate);
-                    let def = match self.cstore.load_macro_untracked(def_id, self.cx.sess()) {
-                        LoadedMacro::MacroDef(macro_def) => macro_def,
-                        // FIXME(jseyfried): document proc macro re-exports
-                        LoadedMacro::ProcMacro(..) => continue,
-                    };
-
-                    let matchers = if let ast::ItemKind::MacroDef(ref def) = def.node {
-                        let tts: Vec<_> = def.stream().into_trees().collect();
-                        tts.chunks(4).map(|arm| arm[0].span()).collect()
-                    } else {
-                        unreachable!()
-                    };
-
-                    debug!("inlining macro {}", def.ident.name);
-                    om.macros.push(Macro {
-                        def_id,
-                        attrs: def.attrs.clone().into(),
-                        name: def.ident.name,
-                        whence: self.cx.tcx.def_span(def_id),
-                        matchers,
-                        stab: self.cx.tcx.lookup_stability(def_id).cloned(),
-                        depr: self.cx.tcx.lookup_deprecation(def_id),
-                        imported_from: Some(imported_from),
-                    })
-                }
-            }
-        }
         om
     }
 

src/test/rustdoc/cross-crate-links.rs

@@ -66,6 +66,6 @@ pub use all_item_types::FOO_STATIC;
 #[doc(no_inline)]
 pub use all_item_types::FOO_CONSTANT;
 
-// @has 'foo/index.html' '//a[@href="../foo/macro.foo_macro.html"]' 'foo_macro'
+// @has 'foo/index.html' '//a[@href="../all_item_types/macro.foo_macro.html"]' 'foo_macro'
 #[doc(no_inline)]
 pub use all_item_types::foo_macro;

src/test/rustdoc/inline_cross/auxiliary/macro-vis.rs

@@ -0,0 +1,35 @@
+// Copyright 2012-2013 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.
+
+#![crate_name = "qwop"]
+
+/// (writen on a spider's web) Some Macro
+#[macro_export]
+macro_rules! some_macro {
+    () => {
+        println!("this is some macro, for sure");
+    };
+}
+
+/// Some other macro, to fill space.
+#[macro_export]
+macro_rules! other_macro {
+    () => {
+        println!("this is some other macro, whatev");
+    };
+}
+
+/// This macro is so cool, it's Super.
+#[macro_export]
+macro_rules! super_macro {
+    () => {
+        println!("is it a bird? a plane? no, it's Super Macro!");
+    };
+}

src/test/rustdoc/inline_cross/macro-vis.rs

@@ -0,0 +1,48 @@
+// Copyright 2012-2013 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.
+
+// aux-build:macro-vis.rs
+// build-aux-docs
+// ignore-cross-compile
+
+#![feature(use_extern_macros)]
+
+#[macro_use] extern crate qwop;
+
+// @has macro_vis/macro.some_macro.html
+// @has macro_vis/index.html '//a/@href' 'macro.some_macro.html'
+pub use qwop::some_macro;
+
+// @has macro_vis/macro.renamed_macro.html
+// @!has - '//pre' 'some_macro'
+// @has macro_vis/index.html '//a/@href' 'macro.renamed_macro.html'
+#[doc(inline)]
+pub use qwop::some_macro as renamed_macro;
+
+// @!has macro_vis/macro.other_macro.html
+// @!has macro_vis/index.html '//a/@href' 'macro.other_macro.html'
+// @!has - '//code' 'pub use qwop::other_macro;'
+#[doc(hidden)]
+pub use qwop::other_macro;
+
+// @has macro_vis/index.html '//code' 'pub use qwop::super_macro;'
+// @!has macro_vis/macro.super_macro.html
+#[doc(no_inline)]
+pub use qwop::super_macro;
+
+// @has macro_vis/macro.this_is_dope.html
+// @has macro_vis/index.html '//a/@href' 'macro.this_is_dope.html'
+/// What it says on the tin.
+#[macro_export]
+macro_rules! this_is_dope {
+    () => {
+        println!("yo check this out");
+    };
+}

src/test/rustdoc/pub-use-extern-macros.rs

@@ -23,7 +23,7 @@ pub use macros::bar;
 #[doc(inline)]
 pub use macros::baz;
 
-// @has pub_use_extern_macros/macro.quux.html
+// @!has pub_use_extern_macros/macro.quux.html
 // @!has pub_use_extern_macros/index.html '//code' 'pub use macros::quux;'
 #[doc(hidden)]
 pub use macros::quux;