Load macros from `#[macro_use]` extern crates in `resolve`.

src/librustc/middle/cstore.rs

@@ -36,9 +36,10 @@
 use session::search_paths::PathKind;
 use util::nodemap::{NodeSet, DefIdMap};
 use std::path::PathBuf;
+use std::rc::Rc;
 use syntax::ast;
 use syntax::attr;
-use syntax::ext::base::LoadedMacro;
+use syntax::ext::base::MultiItemModifier;
 use syntax::ptr::P;
 use syntax::parse::token::InternedString;
 use syntax_pos::Span;
@@ -422,6 +423,11 @@ fn encode_metadata<'a>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
     fn metadata_encoding_version(&self) -> &[u8] { bug!("metadata_encoding_version") }
 }
 
+pub enum LoadedMacro {
+    Def(ast::MacroDef),
+    CustomDerive(String, Rc<MultiItemModifier>),
+}
+
 pub trait CrateLoader {
     fn load_macros(&mut self, extern_crate: &ast::Item, allows_macros: bool) -> Vec<LoadedMacro>;
     fn process_item(&mut self, item: &ast::Item, defs: &Definitions);

src/librustc_driver/driver.rs

@@ -43,6 +43,7 @@
 use serialize::json;
 
 use std::env;
+use std::mem;
 use std::ffi::{OsString, OsStr};
 use std::fs;
 use std::io::{self, Write};
@@ -686,6 +687,8 @@ pub fn phase_2_configure_and_expand<'a, F>(sess: &Session,
         ret
     });
 
+    krate.exported_macros = mem::replace(&mut resolver.exported_macros, Vec::new());
+
     krate = time(time_passes, "maybe building test harness", || {
         syntax::test::modify_for_testing(&sess.parse_sess,
                                          &mut resolver,

src/librustc_metadata/creader.rs

@@ -17,6 +17,7 @@
 
 use rustc::hir::def_id::{CrateNum, DefIndex};
 use rustc::hir::svh::Svh;
+use rustc::middle::cstore::LoadedMacro;
 use rustc::session::{config, Session};
 use rustc::session::config::PanicStrategy;
 use rustc::session::search_paths::PathKind;
@@ -32,7 +33,6 @@
 use std::fs;
 
 use syntax::ast;
-use syntax::ext::base::LoadedMacro;
 use syntax::abi::Abi;
 use syntax::parse;
 use syntax::attr;

src/librustc_metadata/macro_import.rs

@@ -11,12 +11,14 @@
 //! Used by `rustc` when loading a crate with exported macros.
 
 use std::collections::HashSet;
+use std::rc::Rc;
 use std::env;
 use std::mem;
 
 use creader::{CrateLoader, Macros};
 
 use rustc::hir::def_id::DefIndex;
+use rustc::middle::cstore::LoadedMacro;
 use rustc::session::Session;
 use rustc::util::nodemap::FnvHashMap;
 use rustc_back::dynamic_lib::DynamicLibrary;
@@ -24,7 +26,6 @@
 use rustc_macro::__internal::Registry;
 use syntax::ast;
 use syntax::attr;
-use syntax::ext::base::LoadedMacro;
 use syntax::parse::token;
 use syntax_ext::deriving::custom::CustomDerive;
 use syntax_pos::Span;
@@ -204,9 +205,8 @@ impl<'a> Registry for MyRegistrar<'a> {
             fn register_custom_derive(&mut self,
                                       trait_name: &str,
                                       expand: fn(TokenStream) -> TokenStream) {
-                let derive = Box::new(CustomDerive::new(expand));
-                self.0.push(LoadedMacro::CustomDerive(trait_name.to_string(),
-                                                      derive));
+                let derive = Rc::new(CustomDerive::new(expand));
+                self.0.push(LoadedMacro::CustomDerive(trait_name.to_string(), derive));
             }
         }
 

src/librustc_resolve/lib.rs

@@ -53,6 +53,7 @@
 use rustc::hir::{Freevar, FreevarMap, TraitCandidate, TraitMap, GlobMap};
 use rustc::util::nodemap::{NodeMap, NodeSet, FnvHashMap, FnvHashSet};
 
+use syntax::ext::base::MultiItemModifier;
 use syntax::ext::hygiene::Mark;
 use syntax::ast::{self, FloatTy};
 use syntax::ast::{CRATE_NODE_ID, Name, NodeId, IntTy, UintTy};
@@ -71,6 +72,7 @@
 use errors::DiagnosticBuilder;
 
 use std::cell::{Cell, RefCell};
+use std::rc::Rc;
 use std::fmt;
 use std::mem::replace;
 
@@ -1066,6 +1068,8 @@ pub struct Resolver<'a> {
     dummy_binding: &'a NameBinding<'a>,
     new_import_semantics: bool, // true if `#![feature(item_like_imports)]`
 
+    pub exported_macros: Vec<ast::MacroDef>,
+    pub derive_modes: FnvHashMap<Name, Rc<MultiItemModifier>>,
     crate_loader: &'a mut CrateLoader,
     macro_names: FnvHashSet<Name>,
 
@@ -1240,6 +1244,8 @@ pub fn new(session: &'a Session,
             }),
             new_import_semantics: session.features.borrow().item_like_imports,
 
+            exported_macros: Vec::new(),
+            derive_modes: FnvHashMap(),
             crate_loader: crate_loader,
             macro_names: FnvHashSet(),
             expansion_data: expansion_data,

src/librustc_resolve/macros.rs

@@ -9,19 +9,23 @@
 // except according to those terms.
 
 use Resolver;
+use rustc::middle::cstore::LoadedMacro;
 use rustc::util::nodemap::FnvHashMap;
 use std::cell::RefCell;
 use std::mem;
 use std::rc::Rc;
 use syntax::ast::{self, Name};
 use syntax::errors::DiagnosticBuilder;
-use syntax::ext::base::{self, LoadedMacro, MultiModifier, MultiDecorator};
-use syntax::ext::base::{NormalTT, SyntaxExtension};
+use syntax::ext::base::{self, MultiModifier, MultiDecorator, MultiItemModifier};
+use syntax::ext::base::{NormalTT, Resolver as SyntaxResolver, SyntaxExtension};
 use syntax::ext::expand::{Expansion, Invocation, InvocationKind};
 use syntax::ext::hygiene::Mark;
-use syntax::parse::token::intern;
+use syntax::ext::tt::macro_rules;
+use syntax::feature_gate::{self, emit_feature_err};
+use syntax::parse::token::{self, intern};
 use syntax::util::lev_distance::find_best_match_for_name;
 use syntax::visit::{self, Visitor};
+use syntax_pos::Span;
 
 #[derive(Clone, Default)]
 pub struct ExpansionData {
@@ -37,10 +41,6 @@ struct ModuleData {
 }
 
 impl<'a> base::Resolver for Resolver<'a> {
-    fn load_crate(&mut self, extern_crate: &ast::Item, allows_macros: bool) -> Vec<LoadedMacro> {
-        self.crate_loader.load_macros(extern_crate, allows_macros)
-    }
-
     fn next_node_id(&mut self) -> ast::NodeId {
         self.session.next_node_id()
     }
@@ -52,7 +52,18 @@ fn visit_expansion(&mut self, mark: Mark, expansion: &Expansion) {
         });
     }
 
-    fn add_macro(&mut self, scope: Mark, ident: ast::Ident, ext: Rc<SyntaxExtension>) {
+    fn add_macro(&mut self, scope: Mark, mut def: ast::MacroDef) {
+        if def.use_locally {
+            let ext = macro_rules::compile(&self.session.parse_sess, &def);
+            self.add_ext(scope, def.ident, Rc::new(ext));
+        }
+        if def.export {
+            def.id = self.next_node_id();
+            self.exported_macros.push(def);
+        }
+    }
+
+    fn add_ext(&mut self, scope: Mark, ident: ast::Ident, ext: Rc<SyntaxExtension>) {
         if let NormalTT(..) = *ext {
             self.macro_names.insert(ident.name);
         }
@@ -116,6 +127,10 @@ fn resolve_invoc(&mut self, scope: Mark, invoc: &Invocation) -> Option<Rc<Syntax
         err.emit();
         None
     }
+
+    fn resolve_derive_mode(&mut self, ident: ast::Ident) -> Option<Rc<MultiItemModifier>> {
+        self.derive_modes.get(&ident.name).cloned()
+    }
 }
 
 impl<'a> Resolver<'a> {
@@ -128,6 +143,17 @@ fn suggest_macro_name(&mut self, name: &str, err: &mut DiagnosticBuilder<'a>) {
             }
         }
     }
+
+    fn insert_custom_derive(&mut self, name: &str, ext: Rc<MultiItemModifier>, sp: Span) {
+        if !self.session.features.borrow().rustc_macro {
+            let diagnostic = &self.session.parse_sess.span_diagnostic;
+            let msg = "loading custom derive macro crates is experimentally supported";
+            emit_feature_err(diagnostic, "rustc_macro", sp, feature_gate::GateIssue::Language, msg);
+        }
+        if self.derive_modes.insert(token::intern(name), ext).is_some() {
+            self.session.span_err(sp, &format!("cannot shadow existing derive mode `{}`", name));
+        }
+    }
 }
 
 struct ExpansionVisitor<'b, 'a: 'b> {
@@ -201,6 +227,21 @@ fn visit_item(&mut self, item: &ast::Item) {
                 visit::walk_item(self, item);
                 self.current_module = orig_module;
             }
+            ast::ItemKind::ExternCrate(..) => {
+                // We need to error on `#[macro_use] extern crate` when it isn't at the
+                // crate root, because `$crate` won't work properly.
+                // FIXME(jseyfried): This will be nicer once `ModuleData` is merged with `ModuleS`.
+                let is_crate_root = self.current_module.parent.as_ref().unwrap().parent.is_none();
+                for def in self.resolver.crate_loader.load_macros(item, is_crate_root) {
+                    match def {
+                        LoadedMacro::Def(def) => self.resolver.add_macro(Mark::root(), def),
+                        LoadedMacro::CustomDerive(name, ext) => {
+                            self.resolver.insert_custom_derive(&name, ext, item.span);
+                        }
+                    }
+                }
+                visit::walk_item(self, item);
+            }
             _ => visit::walk_item(self, item),
         }
     }

src/libsyntax/ext/base.rs

@@ -17,8 +17,7 @@
 use errors::DiagnosticBuilder;
 use ext::expand::{self, Invocation, Expansion};
 use ext::hygiene::Mark;
-use ext::tt::macro_rules;
-use fold;
+use fold::{self, Folder};
 use parse;
 use parse::parser::{self, Parser};
 use parse::token;
@@ -26,10 +25,7 @@
 use ptr::P;
 use std_inject;
 use util::small_vector::SmallVector;
-use fold::Folder;
-use feature_gate;
 
-use std::collections::HashMap;
 use std::path::PathBuf;
 use std::rc::Rc;
 use std::default::Default;
@@ -659,35 +655,30 @@ pub enum SyntaxExtension {
 pub type NamedSyntaxExtension = (Name, SyntaxExtension);
 
 pub trait Resolver {
-    fn load_crate(&mut self, extern_crate: &ast::Item, allows_macros: bool) -> Vec<LoadedMacro>;
     fn next_node_id(&mut self) -> ast::NodeId;
 
     fn visit_expansion(&mut self, mark: Mark, expansion: &Expansion);
-    fn add_macro(&mut self, scope: Mark, ident: ast::Ident, ext: Rc<SyntaxExtension>);
+    fn add_macro(&mut self, scope: Mark, def: ast::MacroDef);
+    fn add_ext(&mut self, scope: Mark, ident: ast::Ident, ext: Rc<SyntaxExtension>);
     fn add_expansions_at_stmt(&mut self, id: ast::NodeId, macros: Vec<Mark>);
 
     fn find_attr_invoc(&mut self, attrs: &mut Vec<Attribute>) -> Option<Attribute>;
     fn resolve_invoc(&mut self, scope: Mark, invoc: &Invocation) -> Option<Rc<SyntaxExtension>>;
-}
-
-pub enum LoadedMacro {
-    Def(ast::MacroDef),
-    CustomDerive(String, Box<MultiItemModifier>),
+    fn resolve_derive_mode(&mut self, ident: ast::Ident) -> Option<Rc<MultiItemModifier>>;
 }
 
 pub struct DummyResolver;
 
 impl Resolver for DummyResolver {
-    fn load_crate(&mut self, _extern_crate: &ast::Item, _allows_macros: bool) -> Vec<LoadedMacro> {
-        Vec::new()
-    }
     fn next_node_id(&mut self) -> ast::NodeId { ast::DUMMY_NODE_ID }
 
     fn visit_expansion(&mut self, _invoc: Mark, _expansion: &Expansion) {}
-    fn add_macro(&mut self, _scope: Mark, _ident: ast::Ident, _ext: Rc<SyntaxExtension>) {}
+    fn add_macro(&mut self, _scope: Mark, _def: ast::MacroDef) {}
+    fn add_ext(&mut self, _scope: Mark, _ident: ast::Ident, _ext: Rc<SyntaxExtension>) {}
     fn add_expansions_at_stmt(&mut self, _id: ast::NodeId, _macros: Vec<Mark>) {}
 
     fn find_attr_invoc(&mut self, _attrs: &mut Vec<Attribute>) -> Option<Attribute> { None }
+    fn resolve_derive_mode(&mut self, _ident: ast::Ident) -> Option<Rc<MultiItemModifier>> { None }
     fn resolve_invoc(&mut self, _scope: Mark, _invoc: &Invocation) -> Option<Rc<SyntaxExtension>> {
         None
     }
@@ -717,8 +708,6 @@ pub struct ExtCtxt<'a> {
     pub ecfg: expand::ExpansionConfig<'a>,
     pub crate_root: Option<&'static str>,
     pub resolver: &'a mut Resolver,
-    pub exported_macros: Vec<ast::MacroDef>,
-    pub derive_modes: HashMap<InternedString, Box<MultiItemModifier>>,
     pub current_expansion: ExpansionData,
 }
 
@@ -732,9 +721,7 @@ pub fn new(parse_sess: &'a parse::ParseSess, cfg: ast::CrateConfig,
             cfg: cfg,
             ecfg: ecfg,
             crate_root: None,
-            exported_macros: Vec::new(),
             resolver: resolver,
-            derive_modes: HashMap::new(),
             current_expansion: ExpansionData {
                 mark: Mark::root(),
                 depth: 0,
@@ -811,31 +798,6 @@ pub fn bt_push(&mut self, ei: ExpnInfo) {
     }
     pub fn bt_pop(&mut self) {}
 
-    pub fn insert_macro(&mut self, def: ast::MacroDef) {
-        if def.export {
-            self.exported_macros.push(def.clone());
-        }
-        if def.use_locally {
-            let ext = macro_rules::compile(self.parse_sess, &def);
-            self.resolver.add_macro(self.current_expansion.mark, def.ident, Rc::new(ext));
-        }
-    }
-
-    pub fn insert_custom_derive(&mut self, name: &str, ext: Box<MultiItemModifier>, sp: Span) {
-        if !self.ecfg.enable_rustc_macro() {
-            feature_gate::emit_feature_err(&self.parse_sess.span_diagnostic,
-                                           "rustc_macro",
-                                           sp,
-                                           feature_gate::GateIssue::Language,
-                                           "loading custom derive macro crates \
-                                            is experimentally supported");
-        }
-        let name = token::intern_and_get_ident(name);
-        if self.derive_modes.insert(name.clone(), ext).is_some() {
-            self.span_err(sp, &format!("cannot shadow existing derive mode `{}`", name));
-        }
-    }
-
     pub fn struct_span_warn(&self,
                             sp: Span,
                             msg: &str)
@@ -922,7 +884,7 @@ pub fn initialize(&mut self, user_exts: Vec<NamedSyntaxExtension>, krate: &ast::
 
         for (name, extension) in user_exts {
             let ident = ast::Ident::with_empty_ctxt(name);
-            self.resolver.add_macro(Mark::root(), ident, Rc::new(extension));
+            self.resolver.add_ext(Mark::root(), ident, Rc::new(extension));
         }
 
         let mut module = ModuleData {

src/libsyntax/ext/expand.rs

@@ -199,11 +199,6 @@ fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
             },
             _ => unreachable!(),
         };
-        krate.exported_macros = mem::replace(&mut self.cx.exported_macros, Vec::new());
-
-        for def in &mut krate.exported_macros {
-            def.id = self.cx.resolver.next_node_id()
-        }
 
         if self.cx.parse_sess.span_diagnostic.err_count() > err_count {
             self.cx.parse_sess.span_diagnostic.abort_if_errors();
@@ -672,20 +667,6 @@ fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
                 self.cx.current_expansion.module = orig_module;
                 return result;
             }
-            ast::ItemKind::ExternCrate(..) => {
-                // We need to error on `#[macro_use] extern crate` when it isn't at the
-                // crate root, because `$crate` won't work properly.
-                let is_crate_root = self.cx.current_expansion.module.mod_path.len() == 1;
-                for def in self.cx.resolver.load_crate(&*item, is_crate_root) {
-                    match def {
-                        LoadedMacro::Def(def) => self.cx.insert_macro(def),
-                        LoadedMacro::CustomDerive(name, ext) => {
-                            self.cx.insert_custom_derive(&name, ext, item.span);
-                        }
-                    }
-                }
-                noop_fold_item(item, self)
-            },
             _ => noop_fold_item(item, self),
         }
     }

src/libsyntax/ext/tt/macro_rules.rs

@@ -262,14 +262,15 @@ fn expand(&self,
             attrs: attrs,
         };
 
-        cx.insert_macro(def.clone());
-
         // If keep_macs is true, expands to a MacEager::items instead.
-        if cx.ecfg.keep_macs {
+        let result = if cx.ecfg.keep_macs {
             MacEager::items(placeholders::reconstructed_macro_rules(&def).make_items())
         } else {
             MacEager::items(placeholders::macro_scope_placeholder().make_items())
-        }
+        };
+
+        cx.resolver.add_macro(cx.current_expansion.mark, def);
+        result
     }
 }
 

src/libsyntax_ext/deriving/mod.rs

@@ -195,7 +195,8 @@ pub fn expand_derive(cx: &mut ExtCtxt,
         // If custom derive extensions end up threading through the `#[derive]`
         // attribute, we'll get called again later on to continue expanding
         // those modes.
-        } else if let Some(ext) = cx.derive_modes.remove(&tname) {
+        } else if let Some(ext) =
+                   cx.resolver.resolve_derive_mode(ast::Ident::with_empty_ctxt(intern(&tname))) {
             let remaining_derives = iter.cloned().collect::<Vec<_>>();
             if remaining_derives.len() > 0 {
                 let list = cx.meta_list(titem.span,
@@ -214,7 +215,6 @@ pub fn expand_derive(cx: &mut ExtCtxt,
             let item = Annotatable::Item(item);
             let mut items = ext.expand(cx, mitem.span, &mitem, item);
             items.extend(other_items);
-            cx.derive_modes.insert(tname.clone(), ext);
             return items
 
         // If we've gotten this far then it means that we're in the territory of

src/libsyntax_ext/lib.rs

@@ -57,7 +57,7 @@
 
 pub fn register_builtins(resolver: &mut syntax::ext::base::Resolver, enable_quotes: bool) {
     let mut register = |name, ext| {
-        resolver.add_macro(Mark::root(), ast::Ident::with_empty_ctxt(intern(name)), Rc::new(ext));
+        resolver.add_ext(Mark::root(), ast::Ident::with_empty_ctxt(intern(name)), Rc::new(ext));
     };
 
     register("macro_rules", IdentTT(Box::new(MacroRulesExpander), None, false));