auto merge of #15691 : jbclements/rust/method-field-cleanup, r=alexcrichton

This patch applies the excellent suggestion of @pnkfelix to group the helper methods for method field access into a Trait, making the code much more readable, and much more similar to the way it was before.

18 files changed, 180 insertions, 134 deletions

diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 87333499ec3..0a050850fe9 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -43,6 +43,7 @@ use syntax::ast_map::{PathElem, PathElems};
 use syntax::ast_map;
 use syntax::ast_util::*;
 use syntax::ast_util;
+use syntax::ast_util::PostExpansionMethod;
 use syntax::attr;
 use syntax::attr::AttrMetaMethods;
 use syntax::diagnostic::SpanHandler;
@@ -798,7 +799,7 @@ fn encode_info_for_method(ecx: &EncodeContext,
         } else {
             encode_symbol(ecx, ebml_w, m.def_id.node);
         }
-        encode_method_argument_names(ebml_w, method_fn_decl(&*ast_method));
+        encode_method_argument_names(ebml_w, &*ast_method.pe_fn_decl());
     }
 
     ebml_w.end_tag();
@@ -1240,7 +1241,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
                     encode_method_sort(ebml_w, 'p');
                     encode_inlined_item(ecx, ebml_w,
                                         IIMethodRef(def_id, true, &*m));
-                    encode_method_argument_names(ebml_w, method_fn_decl(m));
+                    encode_method_argument_names(ebml_w, m.pe_fn_decl());
                 }
             }
 
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index d58023a4875..9240547874f 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -31,6 +31,7 @@ use middle::{ty, typeck};
 use util::ppaux::ty_to_string;
 
 use syntax::{ast, ast_map, ast_util, codemap, fold};
+use syntax::ast_util::PostExpansionMethod;
 use syntax::codemap::Span;
 use syntax::fold::Folder;
 use syntax::parse::token;
@@ -136,7 +137,7 @@ pub fn decode_inlined_item(cdata: &cstore::crate_metadata,
         let ident = match ii {
             ast::IIItem(i) => i.ident,
             ast::IIForeign(i) => i.ident,
-            ast::IIMethod(_, _, m) => ast_util::method_ident(&*m),
+            ast::IIMethod(_, _, m) => m.pe_ident(),
         };
         debug!("Fn named: {}", token::get_ident(ident));
         debug!("< Decoded inlined fn: {}::{}",
diff --git a/src/librustc/middle/dead.rs b/src/librustc/middle/dead.rs
index d84c62f744e..8f01ee0564d 100644
--- a/src/librustc/middle/dead.rs
+++ b/src/librustc/middle/dead.rs
@@ -22,8 +22,7 @@ use util::nodemap::NodeSet;
 use std::collections::HashSet;
 use syntax::ast;
 use syntax::ast_map;
-use syntax::ast_util;
-use syntax::ast_util::{local_def, is_local};
+use syntax::ast_util::{local_def, is_local, PostExpansionMethod};
 use syntax::attr::AttrMetaMethods;
 use syntax::attr;
 use syntax::codemap;
@@ -213,7 +212,7 @@ impl<'a> MarkSymbolVisitor<'a> {
                 visit::walk_trait_method(self, &*trait_method, ctxt);
             }
             ast_map::NodeMethod(method) => {
-                visit::walk_block(self, ast_util::method_body(&*method), ctxt);
+                visit::walk_block(self, method.pe_body(), ctxt);
             }
             ast_map::NodeForeignItem(foreign_item) => {
                 visit::walk_foreign_item(self, &*foreign_item, ctxt);
@@ -521,8 +520,7 @@ impl<'a> Visitor<()> for DeadVisitor<'a> {
     // Overwrite so that we don't warn the trait method itself.
     fn visit_trait_method(&mut self, trait_method: &ast::TraitMethod, _: ()) {
         match *trait_method {
-            ast::Provided(ref method) => visit::walk_block(self,
-                                                           ast_util::method_body(&**method), ()),
+            ast::Provided(ref method) => visit::walk_block(self, method.pe_body(), ()),
             ast::Required(_) => ()
         }
     }
diff --git a/src/librustc/middle/effect.rs b/src/librustc/middle/effect.rs
index 415135a2d04..fed2f91ce09 100644
--- a/src/librustc/middle/effect.rs
+++ b/src/librustc/middle/effect.rs
@@ -17,7 +17,7 @@ use middle::typeck::MethodCall;
 use util::ppaux;
 
 use syntax::ast;
-use syntax::ast_util;
+use syntax::ast_util::PostExpansionMethod;
 use syntax::codemap::Span;
 use syntax::visit;
 use syntax::visit::Visitor;
@@ -95,7 +95,7 @@ impl<'a> Visitor<()> for EffectCheckVisitor<'a> {
             visit::FkItemFn(_, _, fn_style, _) =>
                 (true, fn_style == ast::UnsafeFn),
             visit::FkMethod(_, _, method) =>
-                (true, ast_util::method_fn_style(method) == ast::UnsafeFn),
+                (true, method.pe_fn_style() == ast::UnsafeFn),
             _ => (false, false),
         };
 
diff --git a/src/librustc/middle/privacy.rs b/src/librustc/middle/privacy.rs
index 580e7b2db57..74ca13a0821 100644
--- a/src/librustc/middle/privacy.rs
+++ b/src/librustc/middle/privacy.rs
@@ -26,8 +26,7 @@ use util::nodemap::{NodeMap, NodeSet};
 
 use syntax::ast;
 use syntax::ast_map;
-use syntax::ast_util;
-use syntax::ast_util::{is_local, local_def};
+use syntax::ast_util::{is_local, local_def, PostExpansionMethod};
 use syntax::attr;
 use syntax::codemap::Span;
 use syntax::parse::token;
@@ -264,10 +263,10 @@ impl<'a> Visitor<()> for EmbargoVisitor<'a> {
 
                 if public_ty || public_trait {
                     for method in methods.iter() {
-                        let meth_public = match ast_util::method_explicit_self(&**method).node {
+                        let meth_public = match method.pe_explicit_self().node {
                             ast::SelfStatic => public_ty,
                             _ => true,
-                        } && ast_util::method_vis(&**method) == ast::Public;
+                        } && method.pe_vis() == ast::Public;
                         if meth_public || tr.is_some() {
                             self.exported_items.insert(method.id);
                         }
@@ -457,8 +456,8 @@ impl<'a> PrivacyVisitor<'a> {
                     let imp = self.tcx.map.get_parent_did(closest_private_id);
                     match ty::impl_trait_ref(self.tcx, imp) {
                         Some(..) => return Allowable,
-                        _ if ast_util::method_vis(&**m) == ast::Public => return Allowable,
-                        _ => ast_util::method_vis(&**m)
+                        _ if m.pe_vis() == ast::Public => return Allowable,
+                        _ => m.pe_vis()
                     }
                 }
                 Some(ast_map::NodeTraitMethod(_)) => {
@@ -1079,7 +1078,7 @@ impl<'a> SanePrivacyVisitor<'a> {
                                 "visibility qualifiers have no effect on trait \
                                  impls");
                 for m in methods.iter() {
-                    check_inherited(m.span, ast_util::method_vis(&**m), "");
+                    check_inherited(m.span, m.pe_vis(), "");
                 }
             }
 
@@ -1111,7 +1110,7 @@ impl<'a> SanePrivacyVisitor<'a> {
                 for m in methods.iter() {
                     match *m {
                         ast::Provided(ref m) => {
-                            check_inherited(m.span, ast_util::method_vis(&**m),
+                            check_inherited(m.span, m.pe_vis(),
                                             "unnecessary visibility");
                         }
                         ast::Required(ref m) => {
@@ -1149,7 +1148,7 @@ impl<'a> SanePrivacyVisitor<'a> {
         match item.node {
             ast::ItemImpl(_, _, _, ref methods) => {
                 for m in methods.iter() {
-                    check_inherited(tcx, m.span, ast_util::method_vis(&**m));
+                    check_inherited(tcx, m.span, m.pe_vis());
                 }
             }
             ast::ItemForeignMod(ref fm) => {
@@ -1175,7 +1174,7 @@ impl<'a> SanePrivacyVisitor<'a> {
                     match *m {
                         ast::Required(..) => {}
                         ast::Provided(ref m) => check_inherited(tcx, m.span,
-                                                                ast_util::method_vis(&**m)),
+                                                                m.pe_vis()),
                     }
                 }
             }
@@ -1345,7 +1344,7 @@ impl<'a> Visitor<()> for VisiblePrivateTypesVisitor<'a> {
                     // methods will be visible as `Public::foo`.
                     let mut found_pub_static = false;
                     for method in methods.iter() {
-                        if ast_util::method_explicit_self(&**method).node == ast::SelfStatic &&
+                        if method.pe_explicit_self().node == ast::SelfStatic &&
                             self.exported_items.contains(&method.id) {
                             found_pub_static = true;
                             visit::walk_method_helper(self, &**method, ());
diff --git a/src/librustc/middle/reachable.rs b/src/librustc/middle/reachable.rs
index d9324574da7..b228a82bdf7 100644
--- a/src/librustc/middle/reachable.rs
+++ b/src/librustc/middle/reachable.rs
@@ -26,7 +26,7 @@ use std::collections::HashSet;
 use syntax::abi;
 use syntax::ast;
 use syntax::ast_map;
-use syntax::ast_util::is_local;
+use syntax::ast_util::{is_local, PostExpansionMethod};
 use syntax::ast_util;
 use syntax::attr::{InlineAlways, InlineHint, InlineNever, InlineNone};
 use syntax::attr;
@@ -68,7 +68,7 @@ fn item_might_be_inlined(item: &ast::Item) -> bool {
 fn method_might_be_inlined(tcx: &ty::ctxt, method: &ast::Method,
                            impl_src: ast::DefId) -> bool {
     if attributes_specify_inlining(method.attrs.as_slice()) ||
-        generics_require_inlining(ast_util::method_generics(&*method)) {
+        generics_require_inlining(method.pe_generics()) {
         return true
     }
     if is_local(impl_src) {
@@ -200,7 +200,7 @@ impl<'a> ReachableContext<'a> {
                 }
             }
             Some(ast_map::NodeMethod(method)) => {
-                if generics_require_inlining(ast_util::method_generics(&*method)) ||
+                if generics_require_inlining(method.pe_generics()) ||
                         attributes_specify_inlining(method.attrs.as_slice()) {
                     true
                 } else {
@@ -316,14 +316,14 @@ impl<'a> ReachableContext<'a> {
                         // Keep going, nothing to get exported
                     }
                     ast::Provided(ref method) => {
-                        visit::walk_block(self, ast_util::method_body(&**method), ())
+                        visit::walk_block(self, method.pe_body(), ())
                     }
                 }
             }
             ast_map::NodeMethod(method) => {
                 let did = self.tcx.map.get_parent_did(search_item);
                 if method_might_be_inlined(self.tcx, &*method, did) {
-                    visit::walk_block(self, ast_util::method_body(&*method), ())
+                    visit::walk_block(self, method.pe_body(), ())
                 }
             }
             // Nothing to recurse on for these
diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs
index 6c6ac81b985..40237e7984f 100644
--- a/src/librustc/middle/resolve.rs
+++ b/src/librustc/middle/resolve.rs
@@ -22,8 +22,7 @@ use util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
 
 use syntax::ast::*;
 use syntax::ast;
-use syntax::ast_util;
-use syntax::ast_util::{local_def};
+use syntax::ast_util::{local_def, PostExpansionMethod};
 use syntax::ast_util::{walk_pat, trait_method_to_ty_method};
 use syntax::ext::mtwt;
 use syntax::parse::token::special_names;
@@ -1299,20 +1298,20 @@ impl<'a> Resolver<'a> {
                         // For each method...
                         for method in methods.iter() {
                             // Add the method to the module.
-                            let ident = ast_util::method_ident(&**method);
+                            let ident = method.pe_ident();
                             let method_name_bindings =
                                 self.add_child(ident,
                                                new_parent.clone(),
                                                ForbidDuplicateValues,
                                                method.span);
-                            let def = match ast_util::method_explicit_self(&**method).node {
+                            let def = match method.pe_explicit_self().node {
                                 SelfStatic => {
                                     // Static methods become
                                     // `def_static_method`s.
                                     DefStaticMethod(local_def(method.id),
                                                       FromImpl(local_def(
                                                         item.id)),
-                                                    ast_util::method_fn_style(&**method))
+                                                      method.pe_fn_style())
                                 }
                                 _ => {
                                     // Non-static methods become
@@ -1321,7 +1320,7 @@ impl<'a> Resolver<'a> {
                                 }
                             };
 
-                            let is_public = ast_util::method_vis(&**method) == ast::Public;
+                            let is_public = method.pe_vis() == ast::Public;
                             method_name_bindings.define_value(def,
                                                               method.span,
                                                               is_public);
@@ -4004,15 +4003,14 @@ impl<'a> Resolver<'a> {
     fn resolve_method(&mut self,
                       rib_kind: RibKind,
                       method: &Method) {
-        let method_generics = ast_util::method_generics(method);
+        let method_generics = method.pe_generics();
         let type_parameters = HasTypeParameters(method_generics,
                                                 FnSpace,
                                                 method.id,
                                                 rib_kind);
 
-        self.resolve_function(rib_kind, Some(ast_util::method_fn_decl(method)),
-                              type_parameters,
-                              ast_util::method_body(method));
+        self.resolve_function(rib_kind, Some(method.pe_fn_decl()), type_parameters,
+                              method.pe_body());
     }
 
     fn with_current_self_type<T>(&mut self, self_type: &Ty, f: |&mut Resolver| -> T) -> T {
@@ -4083,7 +4081,7 @@ impl<'a> Resolver<'a> {
     fn check_trait_method(&self, method: &Method) {
         // If there is a TraitRef in scope for an impl, then the method must be in the trait.
         for &(did, ref trait_ref) in self.current_trait_ref.iter() {
-            let method_name = ast_util::method_ident(method).name;
+            let method_name = method.pe_ident().name;
 
             if self.method_map.borrow().find(&(method_name, did)).is_none() {
                 let path_str = self.path_idents_to_string(&trait_ref.path);
diff --git a/src/librustc/middle/save/mod.rs b/src/librustc/middle/save/mod.rs
index a492b4ab952..9ae2a4c62cd 100644
--- a/src/librustc/middle/save/mod.rs
+++ b/src/librustc/middle/save/mod.rs
@@ -43,6 +43,7 @@ use std::os;
 
 use syntax::ast;
 use syntax::ast_util;
+use syntax::ast_util::PostExpansionMethod;
 use syntax::ast::{NodeId,DefId};
 use syntax::ast_map::NodeItem;
 use syntax::attr;
@@ -333,7 +334,7 @@ impl <'l> DxrVisitor<'l> {
             },
         };
 
-        qualname.push_str(get_ident(ast_util::method_ident(&*method)).get());
+        qualname.push_str(get_ident(method.pe_ident()).get());
         let qualname = qualname.as_slice();
 
         // record the decl for this def (if it has one)
@@ -349,18 +350,17 @@ impl <'l> DxrVisitor<'l> {
                             decl_id,
                             scope_id);
 
-        let m_decl = ast_util::method_fn_decl(&*method);
-        self.process_formals(&m_decl.inputs, qualname, e);
+        self.process_formals(&method.pe_fn_decl().inputs, qualname, e);
 
         // walk arg and return types
-        for arg in m_decl.inputs.iter() {
+        for arg in method.pe_fn_decl().inputs.iter() {
             self.visit_ty(&*arg.ty, e);
         }
-        self.visit_ty(m_decl.output, e);
+        self.visit_ty(method.pe_fn_decl().output, e);
         // walk the fn body
-        self.visit_block(ast_util::method_body(&*method), DxrVisitorEnv::new_nested(method.id));
+        self.visit_block(method.pe_body(), DxrVisitorEnv::new_nested(method.id));
 
-        self.process_generic_params(ast_util::method_generics(&*method),
+        self.process_generic_params(method.pe_generics(),
                                     method.span,
                                     qualname,
                                     method.id,
diff --git a/src/librustc/middle/trans/debuginfo.rs b/src/librustc/middle/trans/debuginfo.rs
index 6e81c10c4a0..49b6f023560 100644
--- a/src/librustc/middle/trans/debuginfo.rs
+++ b/src/librustc/middle/trans/debuginfo.rs
@@ -207,6 +207,7 @@ use std::rc::{Rc, Weak};
 use syntax::util::interner::Interner;
 use syntax::codemap::{Span, Pos};
 use syntax::{abi, ast, codemap, ast_util, ast_map};
+use syntax::ast_util::PostExpansionMethod;
 use syntax::owned_slice::OwnedSlice;
 use syntax::parse::token;
 use syntax::parse::token::special_idents;
@@ -1138,10 +1139,10 @@ pub fn create_function_debug_context(cx: &CrateContext,
             }
         }
         ast_map::NodeMethod(ref method) => {
-            (ast_util::method_ident(&**method),
-             ast_util::method_fn_decl(&**method),
-             ast_util::method_generics(&**method),
-             ast_util::method_body(&**method),
+            (method.pe_ident(),
+             method.pe_fn_decl(),
+             method.pe_generics(),
+             method.pe_body(),
              method.span,
              true)
         }
@@ -1167,10 +1168,10 @@ pub fn create_function_debug_context(cx: &CrateContext,
         ast_map::NodeTraitMethod(ref trait_method) => {
             match **trait_method {
                 ast::Provided(ref method) => {
-                    (ast_util::method_ident(&**method),
-                     ast_util::method_fn_decl(&**method),
-                     ast_util::method_generics(&**method),
-                     ast_util::method_body(&**method),
+                    (method.pe_ident(),
+                     method.pe_fn_decl(),
+                     method.pe_generics(),
+                     method.pe_body(),
                      method.span,
                      true)
                 }
diff --git a/src/librustc/middle/trans/inline.rs b/src/librustc/middle/trans/inline.rs
index d64eeb727e7..bf39f3a6aa3 100644
--- a/src/librustc/middle/trans/inline.rs
+++ b/src/librustc/middle/trans/inline.rs
@@ -16,7 +16,7 @@ use middle::trans::common::*;
 use middle::ty;
 
 use syntax::ast;
-use syntax::ast_util::local_def;
+use syntax::ast_util::{local_def, PostExpansionMethod};
 use syntax::ast_util;
 
 pub fn maybe_instantiate_inline(ccx: &CrateContext, fn_id: ast::DefId)
@@ -128,12 +128,11 @@ pub fn maybe_instantiate_inline(ccx: &CrateContext, fn_id: ast::DefId)
             let impl_tpt = ty::lookup_item_type(ccx.tcx(), impl_did);
             let unparameterized =
                 impl_tpt.generics.types.is_empty() &&
-                ast_util::method_generics(&*mth).ty_params.is_empty();
+                mth.pe_generics().ty_params.is_empty();
 
           if unparameterized {
               let llfn = get_item_val(ccx, mth.id);
-              trans_fn(ccx, ast_util::method_fn_decl(&*mth),
-                       ast_util::method_body(&*mth), llfn,
+                trans_fn(ccx, &*mth.pe_fn_decl(), &*mth.pe_body(), llfn,
                        &param_substs::empty(), mth.id, []);
           }
           local_def(mth.id)
diff --git a/src/librustc/middle/trans/meth.rs b/src/librustc/middle/trans/meth.rs
index 092a524e48a..f9c5f82fb29 100644
--- a/src/librustc/middle/trans/meth.rs
+++ b/src/librustc/middle/trans/meth.rs
@@ -37,7 +37,8 @@ use std::c_str::ToCStr;
 use std::gc::Gc;
 use syntax::abi::Rust;
 use syntax::parse::token;
-use syntax::{ast, ast_map, visit, ast_util};
+use syntax::{ast, ast_map, visit};
+use syntax::ast_util::PostExpansionMethod;
 
 /**
 The main "translation" pass for methods.  Generates code
@@ -65,10 +66,9 @@ pub fn trans_impl(ccx: &CrateContext,
         return;
     }
     for method in methods.iter() {
-        if ast_util::method_generics(&**method).ty_params.len() == 0u {
+        if method.pe_generics().ty_params.len() == 0u {
             let llfn = get_item_val(ccx, method.id);
-            trans_fn(ccx, ast_util::method_fn_decl(&**method),
-                     ast_util::method_body(&**method),
+            trans_fn(ccx, method.pe_fn_decl(), method.pe_body(),
                      llfn, &param_substs::empty(), method.id, []);
         } else {
             let mut v = TransItemVisitor{ ccx: ccx };
@@ -160,7 +160,7 @@ pub fn trans_static_method_callee(bcx: &Block,
             ast_map::NodeTraitMethod(method) => {
                 let ident = match *method {
                     ast::Required(ref m) => m.ident,
-                    ast::Provided(ref m) => ast_util::method_ident(&**m)
+                    ast::Provided(ref m) => m.pe_ident()
                 };
                 ident.name
             }
diff --git a/src/librustc/middle/trans/monomorphize.rs b/src/librustc/middle/trans/monomorphize.rs
index 7687e82654a..6ff6c4741c7 100644
--- a/src/librustc/middle/trans/monomorphize.rs
+++ b/src/librustc/middle/trans/monomorphize.rs
@@ -25,8 +25,7 @@ use util::ppaux::Repr;
 use syntax::abi;
 use syntax::ast;
 use syntax::ast_map;
-use syntax::ast_util;
-use syntax::ast_util::local_def;
+use syntax::ast_util::{local_def, PostExpansionMethod};
 use std::hash::{sip, Hash};
 
 pub fn monomorphic_fn(ccx: &CrateContext,
@@ -182,8 +181,7 @@ pub fn monomorphic_fn(ccx: &CrateContext,
         ast_map::NodeMethod(mth) => {
             let d = mk_lldecl();
             set_llvm_fn_attrs(mth.attrs.as_slice(), d);
-            trans_fn(ccx, ast_util::method_fn_decl(&*mth),
-                     ast_util::method_body(&*mth), d, &psubsts, mth.id, []);
+            trans_fn(ccx, &*mth.pe_fn_decl(), &*mth.pe_body(), d, &psubsts, mth.id, []);
             d
         }
         ast_map::NodeTraitMethod(method) => {
@@ -191,8 +189,8 @@ pub fn monomorphic_fn(ccx: &CrateContext,
                 ast::Provided(mth) => {
                     let d = mk_lldecl();
                     set_llvm_fn_attrs(mth.attrs.as_slice(), d);
-                    trans_fn(ccx, ast_util::method_fn_decl(&*mth),
-                             ast_util::method_body(&*mth), d, &psubsts, mth.id, []);
+                    trans_fn(ccx, &*mth.pe_fn_decl(), &*mth.pe_body(), d,
+                             &psubsts, mth.id, []);
                     d
                 }
                 _ => {
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index 7441f89ac8a..bc4d1c73ffb 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -125,7 +125,7 @@ use syntax::abi;
 use syntax::ast::{Provided, Required};
 use syntax::ast;
 use syntax::ast_map;
-use syntax::ast_util::local_def;
+use syntax::ast_util::{local_def, PostExpansionMethod};
 use syntax::ast_util;
 use syntax::attr;
 use syntax::codemap::Span;
@@ -757,16 +757,14 @@ fn check_method_body(ccx: &CrateCtxt,
     let method_def_id = local_def(method.id);
     let method_ty = ty::method(ccx.tcx, method_def_id);
     let method_generics = &method_ty.generics;
-    let m_body = ast_util::method_body(&*method);
 
     let param_env = ty::construct_parameter_environment(ccx.tcx,
                                                         method_generics,
-                                                        m_body.id);
+                                                        method.pe_body().id);
 
     let fty = ty::node_id_to_type(ccx.tcx, method.id);
 
-    check_bare_fn(ccx, ast_util::method_fn_decl(&*method),
-                  m_body, method.id, fty, param_env);
+    check_bare_fn(ccx, method.pe_fn_decl(), method.pe_body(), method.id, fty, param_env);
 }
 
 fn check_impl_methods_against_trait(ccx: &CrateCtxt,
@@ -794,7 +792,7 @@ fn check_impl_methods_against_trait(ccx: &CrateCtxt,
                 compare_impl_method(ccx.tcx,
                                     &*impl_method_ty,
                                     impl_method.span,
-                                    ast_util::method_body(&**impl_method).id,
+                                    impl_method.pe_body().id,
                                     &**trait_method_ty,
                                     &impl_trait_ref.substs);
             }
@@ -817,7 +815,7 @@ fn check_impl_methods_against_trait(ccx: &CrateCtxt,
     for trait_method in trait_methods.iter() {
         let is_implemented =
             impl_methods.iter().any(
-                |m| ast_util::method_ident(&**m).name == trait_method.ident.name);
+                |m| m.pe_ident().name == trait_method.ident.name);
         let is_provided =
             provided_methods.iter().any(
                 |m| m.ident.name == trait_method.ident.name);
diff --git a/src/librustc/middle/typeck/collect.rs b/src/librustc/middle/typeck/collect.rs
index 7a39dd5b5ab..e21a7949ec7 100644
--- a/src/librustc/middle/typeck/collect.rs
+++ b/src/librustc/middle/typeck/collect.rs
@@ -57,8 +57,7 @@ use syntax::ast::{StaticRegionTyParamBound, OtherRegionTyParamBound};
 use syntax::ast::{TraitTyParamBound, UnboxedFnTyParamBound};
 use syntax::ast;
 use syntax::ast_map;
-use syntax::ast_util;
-use syntax::ast_util::{local_def, method_ident, split_trait_methods};
+use syntax::ast_util::{local_def, split_trait_methods, PostExpansionMethod};
 use syntax::codemap::Span;
 use syntax::codemap;
 use syntax::owned_slice::OwnedSlice;
@@ -214,11 +213,8 @@ pub fn ensure_trait_methods(ccx: &CrateCtxt,
                             &ast::Provided(ref m) => {
                                 ty_method_of_trait_method(
                                     ccx, trait_id, &trait_def.generics,
-                                    &m.id, &ast_util::method_ident(&**m),
-                                    ast_util::method_explicit_self(&**m),
-                                    ast_util::method_generics(&**m),
-                                    &ast_util::method_fn_style(&**m),
-                                    ast_util::method_fn_decl(&**m))
+                                    &m.id, &m.pe_ident(), m.pe_explicit_self(),
+                                    m.pe_generics(), &m.pe_fn_style(), m.pe_fn_decl())
                             }
                         });
 
@@ -334,7 +330,7 @@ fn convert_methods(ccx: &CrateCtxt,
     let tcx = ccx.tcx;
     let mut seen_methods = HashSet::new();
     for m in ms.iter() {
-        if !seen_methods.insert(ast_util::method_ident(&**m).repr(tcx)) {
+        if !seen_methods.insert(m.pe_ident().repr(ccx.tcx)) {
             tcx.sess.span_err(m.span, "duplicate method in trait impl");
         }
 
@@ -346,9 +342,9 @@ fn convert_methods(ccx: &CrateCtxt,
                                        rcvr_visibility));
         let fty = ty::mk_bare_fn(tcx, mty.fty.clone());
         debug!("method {} (id {}) has type {}",
-                method_ident(&**m).repr(tcx),
+                m.pe_ident().repr(ccx.tcx),
                 m.id,
-                fty.repr(tcx));
+                fty.repr(ccx.tcx));
         tcx.tcache.borrow_mut().insert(
             local_def(m.id),
             Polytype {
@@ -369,24 +365,23 @@ fn convert_methods(ccx: &CrateCtxt,
                     rcvr_visibility: ast::Visibility)
                     -> ty::Method
     {
-        let fty = astconv::ty_of_method(ccx, m.id, ast_util::method_fn_style(&*m),
+        let fty = astconv::ty_of_method(ccx, m.id, m.pe_fn_style(),
                                         untransformed_rcvr_ty,
-                                        *ast_util::method_explicit_self(&*m),
-                                        ast_util::method_fn_decl(&*m));
+                                        *m.pe_explicit_self(), m.pe_fn_decl());
 
         // if the method specifies a visibility, use that, otherwise
         // inherit the visibility from the impl (so `foo` in `pub impl
         // { fn foo(); }` is public, but private in `priv impl { fn
         // foo(); }`).
-        let method_vis = ast_util::method_vis(&*m).inherit_from(rcvr_visibility);
+        let method_vis = m.pe_vis().inherit_from(rcvr_visibility);
 
         let m_ty_generics =
-            ty_generics_for_fn_or_method(ccx, ast_util::method_generics(&*m),
+            ty_generics_for_fn_or_method(ccx, m.pe_generics(),
                                          (*rcvr_ty_generics).clone());
-        ty::Method::new(ast_util::method_ident(&*m),
+        ty::Method::new(m.pe_ident(),
                         m_ty_generics,
                         fty,
-                        ast_util::method_explicit_self(&*m).node,
+                        m.pe_explicit_self().node,
                         method_vis,
                         local_def(m.id),
                         container,
diff --git a/src/librustc/middle/typeck/infer/error_reporting.rs b/src/librustc/middle/typeck/infer/error_reporting.rs
index bdd6d96f394..8be1700b635 100644
--- a/src/librustc/middle/typeck/infer/error_reporting.rs
+++ b/src/librustc/middle/typeck/infer/error_reporting.rs
@@ -84,7 +84,7 @@ use std::string::String;
 use syntax::ast;
 use syntax::ast_map;
 use syntax::ast_util;
-use syntax::ast_util::name_to_dummy_lifetime;
+use syntax::ast_util::{name_to_dummy_lifetime, PostExpansionMethod};
 use syntax::owned_slice::OwnedSlice;
 use syntax::codemap;
 use syntax::parse::token;
@@ -700,11 +700,8 @@ impl<'a> ErrorReporting for InferCtxt<'a> {
                     }
                 }
                 ast_map::NodeMethod(ref m) => {
-                    Some((ast_util::method_fn_decl(&**m),
-                          ast_util::method_generics(&**m),
-                          ast_util::method_fn_style(&**m),
-                          ast_util::method_ident(&**m),
-                          Some(ast_util::method_explicit_self(&**m).node), m.span))
+                    Some((m.pe_fn_decl(), m.pe_generics(), m.pe_fn_style(),
+                          m.pe_ident(), Some(m.pe_explicit_self().node), m.span))
                 },
                 _ => None
             },
@@ -1455,7 +1452,7 @@ fn lifetimes_in_scope(tcx: &ty::ctxt,
                 _ => None
             },
             ast_map::NodeMethod(m) => {
-                taken.push_all(ast_util::method_generics(&*m).lifetimes.as_slice());
+                taken.push_all(m.pe_generics().lifetimes.as_slice());
                 Some(m.id)
             },
             _ => None
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 2e3bb2eef7d..fdf98f392a7 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -14,6 +14,7 @@
 use syntax;
 use syntax::ast;
 use syntax::ast_util;
+use syntax::ast_util::PostExpansionMethod;
 use syntax::attr;
 use syntax::attr::{AttributeMethods, AttrMetaMethods};
 use syntax::codemap::Pos;
@@ -695,30 +696,30 @@ pub struct Method {
 
 impl Clean<Item> for ast::Method {
     fn clean(&self) -> Item {
-        let fn_decl = ast_util::method_fn_decl(self);
-        let inputs = match ast_util::method_explicit_self(self).node {
-            ast::SelfStatic => fn_decl.inputs.as_slice(),
-            _ => fn_decl.inputs.slice_from(1)
+        let all_inputs = &self.pe_fn_decl().inputs;
+        let inputs = match self.pe_explicit_self().node {
+            ast::SelfStatic => all_inputs.as_slice(),
+            _ => all_inputs.slice_from(1)
         };
         let decl = FnDecl {
             inputs: Arguments {
                 values: inputs.iter().map(|x| x.clean()).collect(),
             },
-            output: (fn_decl.output.clean()),
-            cf: fn_decl.cf.clean(),
+            output: (self.pe_fn_decl().output.clean()),
+            cf: self.pe_fn_decl().cf.clean(),
             attrs: Vec::new()
         };
         Item {
-            name: Some(ast_util::method_ident(self).clean()),
+            name: Some(self.pe_ident().clean()),
             attrs: self.attrs.clean().move_iter().collect(),
             source: self.span.clean(),
             def_id: ast_util::local_def(self.id),
-            visibility: ast_util::method_vis(self).clean(),
+            visibility: self.pe_vis().clean(),
             stability: get_stability(ast_util::local_def(self.id)),
             inner: MethodItem(Method {
-                generics: ast_util::method_generics(self).clean(),
-                self_: ast_util::method_explicit_self(self).node.clean(),
-                fn_style: ast_util::method_fn_style(self).clone(),
+                generics: self.pe_generics().clean(),
+                self_: self.pe_explicit_self().node.clean(),
+                fn_style: self.pe_fn_style().clone(),
                 decl: decl,
             }),
         }
diff --git a/src/libsyntax/ast_map/blocks.rs b/src/libsyntax/ast_map/blocks.rs
index 1280b884f11..a522f805543 100644
--- a/src/libsyntax/ast_map/blocks.rs
+++ b/src/libsyntax/ast_map/blocks.rs
@@ -26,7 +26,7 @@ use ast::{P, Block, FnDecl, NodeId};
 use ast;
 use ast_map::{Node};
 use ast_map;
-use ast_util;
+use ast_util::PostExpansionMethod;
 use codemap::Span;
 use visit;
 
@@ -152,13 +152,13 @@ impl FnLikeNode {
 
     pub fn body<'a>(&'a self) -> P<Block> {
         self.handle(|i: ItemFnParts|     i.body,
-                    |m: &'a ast::Method| ast_util::method_body(m),
+                    |m: &'a ast::Method| m.pe_body(),
                     |c: ClosureParts|    c.body)
     }
 
     pub fn decl<'a>(&'a self) -> P<FnDecl> {
         self.handle(|i: ItemFnParts|     i.decl,
-                    |m: &'a ast::Method| ast_util::method_fn_decl(m),
+                    |m: &'a ast::Method| m.pe_fn_decl(),
                     |c: ClosureParts|    c.decl)
     }
 
@@ -182,7 +182,7 @@ impl FnLikeNode {
             visit::FkFnBlock
         };
         let method = |m: &'a ast::Method| {
-            visit::FkMethod(ast_util::method_ident(m), ast_util::method_generics(m), m)
+            visit::FkMethod(m.pe_ident(), m.pe_generics(), m)
         };
         self.handle(item, method, closure)
     }
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index a18d8a81ef4..5431a3db16e 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -742,16 +742,48 @@ pub fn static_has_significant_address(mutbl: ast::Mutability,
     inline == InlineNever || inline == InlineNone
 }
 
-
 /// Macro invocations are guaranteed not to occur after expansion is complete.
-/// extracting fields of a method requires a dynamic check to make sure that it's
-/// not a macro invocation, though this check is guaranteed to succeed, assuming
+/// Extracting fields of a method requires a dynamic check to make sure that it's
+/// not a macro invocation. This check is guaranteed to succeed, assuming
 /// that the invocations are indeed gone.
-macro_rules! method_field_extractor {
-    ($fn_name:ident, $field_ty:ty, $field_pat:pat, $result:ident) => {
-        /// Returns the ident of a Method. To be used after expansion is complete
-        pub fn $fn_name<'a>(method: &'a ast::Method) -> $field_ty {
-            match method.node {
+pub trait PostExpansionMethod {
+    fn pe_ident(&self) -> ast::Ident;
+    fn pe_generics<'a>(&'a self) -> &'a ast::Generics;
+    fn pe_explicit_self<'a>(&'a self) -> &'a ast::ExplicitSelf;
+    fn pe_fn_style(&self) -> ast::FnStyle;
+    fn pe_fn_decl(&self) -> P<ast::FnDecl>;
+    fn pe_body(&self) -> P<ast::Block>;
+    fn pe_vis(&self) -> ast::Visibility;
+}
+
+
+/// can't use the standard cfg(stage0) tricks here, because the error occurs in
+/// parsing, before cfg gets a chance to save the day. (yes, interleaved parsing
+/// / expansion / configuring would solve this problem...)
+
+// NOTE: remove after next snapshot
+/// to be more specific: after a snapshot, swap out the "PRE" stuff, and
+// swap in the "POST" stuff.
+
+/// PRE
+macro_rules! mf_method_body{
+    ($slf:ident, $field_pat:pat, $result:ident) => {
+        match $slf.node {
+            $field_pat => $result,
+                MethMac(_) => {
+                    fail!("expected an AST without macro invocations");
+                }
+        }
+    }
+}
+
+/// POST
+/*
+#[cfg(not(stage0))]
+macro_rules! mf_method{
+    ($meth_name:ident, $field_ty:ty, $field_pat:pat, $result:ident) => {
+        fn $meth_name<'a>(&'a self) -> $field_ty {
+            match self.node {
                 $field_pat => $result,
                 MethMac(_) => {
                     fail!("expected an AST without macro invocations");
@@ -759,20 +791,49 @@ macro_rules! method_field_extractor {
             }
         }
     }
+}*/
+
+
+// PRE
+impl PostExpansionMethod for Method {
+    fn pe_ident(&self) -> ast::Ident {
+        mf_method_body!(self,MethDecl(ident,_,_,_,_,_,_),ident)
+    }
+    fn pe_generics<'a>(&'a self) -> &'a ast::Generics {
+        mf_method_body!(self,MethDecl(_,ref generics,_,_,_,_,_),generics)
+    }
+    fn pe_explicit_self<'a>(&'a self) -> &'a ast::ExplicitSelf {
+        mf_method_body!(self,MethDecl(_,_,ref explicit_self,_,_,_,_),explicit_self)
+    }
+    fn pe_fn_style(&self) -> ast::FnStyle{
+        mf_method_body!(self,MethDecl(_,_,_,fn_style,_,_,_),fn_style)
+    }
+    fn pe_fn_decl(&self) -> P<ast::FnDecl> {
+        mf_method_body!(self,MethDecl(_,_,_,_,decl,_,_),decl)
+    }
+    fn pe_body(&self) -> P<ast::Block> {
+        mf_method_body!(self,MethDecl(_,_,_,_,_,body,_),body)
+    }
+    fn pe_vis(&self) -> ast::Visibility {
+        mf_method_body!(self,MethDecl(_,_,_,_,_,_,vis),vis)
+    }
 }
 
-// Note: this is unhygienic in the lifetime 'a. In order to fix this, we'd have to
-// add :lifetime as a macro argument type, so that the 'a could be supplied by the macro
-// invocation.
-pub method_field_extractor!(method_ident,ast::Ident,MethDecl(ident,_,_,_,_,_,_),ident)
-pub method_field_extractor!(method_generics,&'a ast::Generics,
-                            MethDecl(_,ref generics,_,_,_,_,_),generics)
-pub method_field_extractor!(method_explicit_self,&'a ast::ExplicitSelf,
-                            MethDecl(_,_,ref explicit_self,_,_,_,_),explicit_self)
-pub method_field_extractor!(method_fn_style,ast::FnStyle,MethDecl(_,_,_,fn_style,_,_,_),fn_style)
-pub method_field_extractor!(method_fn_decl,P<ast::FnDecl>,MethDecl(_,_,_,_,decl,_,_),decl)
-pub method_field_extractor!(method_body,P<ast::Block>,MethDecl(_,_,_,_,_,body,_),body)
-pub method_field_extractor!(method_vis,ast::Visibility,MethDecl(_,_,_,_,_,_,vis),vis)
+// POST
+/*
+#[cfg(not(stage0))]
+impl PostExpansionMethod for Method {
+    mf_method!(pe_ident,ast::Ident,MethDecl(ident,_,_,_,_,_,_),ident)
+    mf_method!(pe_generics,&'a ast::Generics,
+               MethDecl(_,ref generics,_,_,_,_,_),generics)
+    mf_method!(pe_explicit_self,&'a ast::ExplicitSelf,
+               MethDecl(_,_,ref explicit_self,_,_,_,_),explicit_self)
+    mf_method!(pe_fn_style,ast::FnStyle,MethDecl(_,_,_,fn_style,_,_,_),fn_style)
+    mf_method!(pe_fn_decl,P<ast::FnDecl>,MethDecl(_,_,_,_,decl,_,_),decl)
+    mf_method!(pe_body,P<ast::Block>,MethDecl(_,_,_,_,_,body,_),body)
+    mf_method!(pe_vis,ast::Visibility,MethDecl(_,_,_,_,_,_,vis),vis)
+}
+*/
 
 #[cfg(test)]
 mod test {
@@ -799,4 +860,3 @@ mod test {
                 .iter().map(ident_to_segment).collect::<Vec<PathSegment>>().as_slice()));
     }
 }
-