From 69b6bc5eee9174d0f2ef1e4ff60a6ed06aedf455 Mon Sep 17 00:00:00 2001
From: Keegan McAllister <kmcallister@mozilla.com>
Date: Mon, 2 Jun 2014 15:27:15 -0700
Subject: [PATCH] Convert lints to a trait-based infrastructure

The immediate benefits are

* moving the state specific to a single lint out of Context, and
* replacing the soup of function calls in the Visitor impl with
  more structured control flow

But this is also a step towards loadable lints.
---
 src/librustc/lint/builtin.rs | 2099 +++++++++++++++++++---------------
 src/librustc/lint/mod.rs     |  390 ++++---
 2 files changed, 1397 insertions(+), 1092 deletions(-)

diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 3065645db27..2ca4d3eb4e8 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -11,16 +11,15 @@
 //! Lints built in to rustc.
 
 use metadata::csearch;
-use middle::def;
 use middle::def::*;
-use middle::pat_util;
 use middle::trans::adt; // for `adt::is_ffi_safe`
-use middle::ty;
 use middle::typeck::astconv::{ast_ty_to_ty, AstConv};
 use middle::typeck::infer;
-use middle::typeck;
+use middle::privacy::ExportedItems;
+use middle::{typeck, ty, def, pat_util};
 use util::ppaux::{ty_to_str};
-use lint::Context;
+use util::nodemap::NodeSet;
+use lint::{Context, LintPass};
 use lint;
 
 use std::cmp;
@@ -33,333 +32,405 @@ use std::u16;
 use std::u32;
 use std::u64;
 use std::u8;
+use std::default::Default;
 use syntax::abi;
 use syntax::ast_map;
 use syntax::attr::AttrMetaMethods;
 use syntax::attr;
 use syntax::codemap::Span;
 use syntax::parse::token;
-use syntax::visit::Visitor;
 use syntax::{ast, ast_util, visit};
 
-pub fn check_while_true_expr(cx: &Context, e: &ast::Expr) {
-    match e.node {
-        ast::ExprWhile(cond, _) => {
-            match cond.node {
-                ast::ExprLit(lit) => {
-                    match lit.node {
-                        ast::LitBool(true) => {
-                            cx.span_lint(lint::WhileTrue,
-                                         e.span,
-                                         "denote infinite loops with loop \
-                                          { ... }");
-                        }
-                        _ => {}
-                    }
-                }
-                _ => ()
-            }
-        }
-        _ => ()
-    }
-}
+/// Doesn't actually warn; just gathers information for use by
+/// checks in trans.
+#[deriving(Default)]
+pub struct GatherNodeLevels;
 
-pub fn check_unused_casts(cx: &Context, e: &ast::Expr) {
-    return match e.node {
-        ast::ExprCast(expr, ty) => {
-            let t_t = ast_ty_to_ty(cx, &infer::new_infer_ctxt(cx.tcx), ty);
-            if  ty::get(ty::expr_ty(cx.tcx, expr)).sty == ty::get(t_t).sty {
-                cx.span_lint(lint::UnnecessaryTypecast, ty.span,
-                             "unnecessary type cast");
-            }
-        }
-        _ => ()
-    };
-}
-
-pub fn check_type_limits(cx: &Context, e: &ast::Expr) {
-    return match e.node {
-        ast::ExprUnary(ast::UnNeg, ex) => {
-            match ex.node  {
-                ast::ExprLit(lit) => {
-                    match lit.node {
-                        ast::LitUint(..) => {
-                            cx.span_lint(lint::UnsignedNegate, e.span,
-                                         "negation of unsigned int literal may be unintentional");
-                        },
-                        _ => ()
-                    }
-                },
-                _ => {
-                    let t = ty::expr_ty(cx.tcx, ex);
-                    match ty::get(t).sty {
-                        ty::ty_uint(_) => {
-                            cx.span_lint(lint::UnsignedNegate, e.span,
-                                         "negation of unsigned int variable may be unintentional");
-                        },
-                        _ => ()
-                    }
-                }
-            }
-        },
-        ast::ExprBinary(binop, l, r) => {
-            if is_comparison(binop) && !check_limits(cx.tcx, binop, l, r) {
-                cx.span_lint(lint::TypeLimits, e.span,
-                             "comparison is useless due to type limits");
-            }
-        },
-        ast::ExprLit(lit) => {
-            match ty::get(ty::expr_ty(cx.tcx, e)).sty {
-                ty::ty_int(t) => {
-                    let int_type = if t == ast::TyI {
-                        cx.tcx.sess.targ_cfg.int_type
-                    } else { t };
-                    let (min, max) = int_ty_range(int_type);
-                    let mut lit_val: i64 = match lit.node {
-                        ast::LitInt(v, _) => v,
-                        ast::LitUint(v, _) => v as i64,
-                        ast::LitIntUnsuffixed(v) => v,
-                        _ => fail!()
-                    };
-                    if cx.negated_expr_id == e.id {
-                        lit_val *= -1;
-                    }
-                    if  lit_val < min || lit_val > max {
-                        cx.span_lint(lint::TypeOverflow, e.span,
-                                     "literal out of range for its type");
-                    }
-                },
-                ty::ty_uint(t) => {
-                    let uint_type = if t == ast::TyU {
-                        cx.tcx.sess.targ_cfg.uint_type
-                    } else { t };
-                    let (min, max) = uint_ty_range(uint_type);
-                    let lit_val: u64 = match lit.node {
-                        ast::LitInt(v, _) => v as u64,
-                        ast::LitUint(v, _) => v,
-                        ast::LitIntUnsuffixed(v) => v as u64,
-                        _ => fail!()
-                    };
-                    if  lit_val < min || lit_val > max {
-                        cx.span_lint(lint::TypeOverflow, e.span,
-                                     "literal out of range for its type");
-                    }
-                },
-
-                _ => ()
-            };
-        },
-        _ => ()
-    };
-
-    fn is_valid<T:cmp::PartialOrd>(binop: ast::BinOp, v: T,
-                            min: T, max: T) -> bool {
-        match binop {
-            ast::BiLt => v >  min && v <= max,
-            ast::BiLe => v >= min && v <  max,
-            ast::BiGt => v >= min && v <  max,
-            ast::BiGe => v >  min && v <= max,
-            ast::BiEq | ast::BiNe => v >= min && v <= max,
-            _ => fail!()
-        }
-    }
-
-    fn rev_binop(binop: ast::BinOp) -> ast::BinOp {
-        match binop {
-            ast::BiLt => ast::BiGt,
-            ast::BiLe => ast::BiGe,
-            ast::BiGt => ast::BiLt,
-            ast::BiGe => ast::BiLe,
-            _ => binop
-        }
-    }
-
-    // for int & uint, be conservative with the warnings, so that the
-    // warnings are consistent between 32- and 64-bit platforms
-    fn int_ty_range(int_ty: ast::IntTy) -> (i64, i64) {
-        match int_ty {
-            ast::TyI =>    (i64::MIN,        i64::MAX),
-            ast::TyI8 =>   (i8::MIN  as i64, i8::MAX  as i64),
-            ast::TyI16 =>  (i16::MIN as i64, i16::MAX as i64),
-            ast::TyI32 =>  (i32::MIN as i64, i32::MAX as i64),
-            ast::TyI64 =>  (i64::MIN,        i64::MAX)
-        }
-    }
-
-    fn uint_ty_range(uint_ty: ast::UintTy) -> (u64, u64) {
-        match uint_ty {
-            ast::TyU =>   (u64::MIN,         u64::MAX),
-            ast::TyU8 =>  (u8::MIN   as u64, u8::MAX   as u64),
-            ast::TyU16 => (u16::MIN  as u64, u16::MAX  as u64),
-            ast::TyU32 => (u32::MIN  as u64, u32::MAX  as u64),
-            ast::TyU64 => (u64::MIN,         u64::MAX)
-        }
-    }
-
-    fn check_limits(tcx: &ty::ctxt, binop: ast::BinOp,
-                    l: &ast::Expr, r: &ast::Expr) -> bool {
-        let (lit, expr, swap) = match (&l.node, &r.node) {
-            (&ast::ExprLit(_), _) => (l, r, true),
-            (_, &ast::ExprLit(_)) => (r, l, false),
-            _ => return true
-        };
-        // Normalize the binop so that the literal is always on the RHS in
-        // the comparison
-        let norm_binop = if swap { rev_binop(binop) } else { binop };
-        match ty::get(ty::expr_ty(tcx, expr)).sty {
-            ty::ty_int(int_ty) => {
-                let (min, max) = int_ty_range(int_ty);
-                let lit_val: i64 = match lit.node {
-                    ast::ExprLit(li) => match li.node {
-                        ast::LitInt(v, _) => v,
-                        ast::LitUint(v, _) => v as i64,
-                        ast::LitIntUnsuffixed(v) => v,
-                        _ => return true
+impl LintPass for GatherNodeLevels {
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        match it.node {
+            ast::ItemEnum(..) => {
+                match cx.cur.find(&(lint::VariantSizeDifference as uint)) {
+                    Some(&(lvl, src)) if lvl != lint::Allow => {
+                        cx.insert_node_level(it.id, lint::VariantSizeDifference, lvl, src);
                     },
-                    _ => fail!()
-                };
-                is_valid(norm_binop, lit_val, min, max)
-            }
-            ty::ty_uint(uint_ty) => {
-                let (min, max): (u64, u64) = uint_ty_range(uint_ty);
-                let lit_val: u64 = match lit.node {
-                    ast::ExprLit(li) => match li.node {
-                        ast::LitInt(v, _) => v as u64,
-                        ast::LitUint(v, _) => v,
-                        ast::LitIntUnsuffixed(v) => v as u64,
-                        _ => return true
-                    },
-                    _ => fail!()
-                };
-                is_valid(norm_binop, lit_val, min, max)
-            }
-            _ => true
-        }
-    }
-
-    fn is_comparison(binop: ast::BinOp) -> bool {
-        match binop {
-            ast::BiEq | ast::BiLt | ast::BiLe |
-            ast::BiNe | ast::BiGe | ast::BiGt => true,
-            _ => false
+                    _ => { }
+                }
+            },
+            _ => { }
         }
     }
 }
 
-pub fn check_item_ctypes(cx: &Context, it: &ast::Item) {
-    fn check_ty(cx: &Context, ty: &ast::Ty) {
-        match ty.node {
-            ast::TyPath(_, _, id) => {
-                match cx.tcx.def_map.borrow().get_copy(&id) {
-                    def::DefPrimTy(ast::TyInt(ast::TyI)) => {
-                        cx.span_lint(lint::CTypes, ty.span,
-                                "found rust type `int` in foreign module, while \
-                                libc::c_int or libc::c_long should be used");
-                    }
-                    def::DefPrimTy(ast::TyUint(ast::TyU)) => {
-                        cx.span_lint(lint::CTypes, ty.span,
-                                "found rust type `uint` in foreign module, while \
-                                libc::c_uint or libc::c_ulong should be used");
-                    }
-                    def::DefTy(def_id) => {
-                        if !adt::is_ffi_safe(cx.tcx, def_id) {
-                            cx.span_lint(lint::CTypes, ty.span,
-                                         "found enum type without foreign-function-safe \
-                                          representation annotation in foreign module");
-                            // hmm... this message could be more helpful
+#[deriving(Default)]
+pub struct WhileTrue;
+
+impl LintPass for WhileTrue {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        match e.node {
+            ast::ExprWhile(cond, _) => {
+                match cond.node {
+                    ast::ExprLit(lit) => {
+                        match lit.node {
+                            ast::LitBool(true) => {
+                                cx.span_lint(lint::WhileTrue,
+                                             e.span,
+                                             "denote infinite loops with loop \
+                                              { ... }");
+                            }
+                            _ => {}
                         }
                     }
                     _ => ()
                 }
             }
-            ast::TyPtr(ref mt) => { check_ty(cx, mt.ty) }
-            _ => {}
+            _ => ()
         }
     }
-
-    fn check_foreign_fn(cx: &Context, decl: &ast::FnDecl) {
-        for input in decl.inputs.iter() {
-            check_ty(cx, input.ty);
-        }
-        check_ty(cx, decl.output)
-    }
-
-    match it.node {
-      ast::ItemForeignMod(ref nmod) if nmod.abi != abi::RustIntrinsic => {
-        for ni in nmod.items.iter() {
-            match ni.node {
-                ast::ForeignItemFn(decl, _) => check_foreign_fn(cx, decl),
-                ast::ForeignItemStatic(t, _) => check_ty(cx, t)
-            }
-        }
-      }
-      _ => {/* nothing to do */ }
-    }
 }
 
-pub fn check_heap_type(cx: &Context, span: Span, ty: ty::t) {
-    let xs = [lint::ManagedHeapMemory, lint::OwnedHeapMemory, lint::HeapMemory];
-    for &lint in xs.iter() {
-        if cx.get_level(lint) == lint::Allow { continue }
+#[deriving(Default)]
+pub struct UnusedCasts;
 
-        let mut n_box = 0;
-        let mut n_uniq = 0;
-        ty::fold_ty(cx.tcx, ty, |t| {
-            match ty::get(t).sty {
-                ty::ty_box(_) => {
-                    n_box += 1;
-                }
-                ty::ty_uniq(_) |
-                ty::ty_trait(box ty::TyTrait {
-                    store: ty::UniqTraitStore, ..
-                }) |
-                ty::ty_closure(box ty::ClosureTy {
-                    store: ty::UniqTraitStore,
-                    ..
-                }) => {
-                    n_uniq += 1;
+impl LintPass for UnusedCasts {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        match e.node {
+            ast::ExprCast(expr, ty) => {
+                let t_t = ast_ty_to_ty(cx, &infer::new_infer_ctxt(cx.tcx), ty);
+                if  ty::get(ty::expr_ty(cx.tcx, expr)).sty == ty::get(t_t).sty {
+                    cx.span_lint(lint::UnnecessaryTypecast, ty.span,
+                                 "unnecessary type cast");
                 }
+            }
+            _ => ()
+        }
+    }
+}
 
-                _ => ()
+pub struct TypeLimits {
+    /// Id of the last visited negated expression
+    negated_expr_id: ast::NodeId,
+}
+
+impl Default for TypeLimits {
+    fn default() -> TypeLimits {
+        TypeLimits {
+            negated_expr_id: -1,
+        }
+    }
+}
+
+impl LintPass for TypeLimits {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        match e.node {
+            ast::ExprUnary(ast::UnNeg, expr) => {
+                match expr.node  {
+                    ast::ExprLit(lit) => {
+                        match lit.node {
+                            ast::LitUint(..) => {
+                                cx.span_lint(lint::UnsignedNegate, e.span,
+                                             "negation of unsigned int literal may \
+                                             be unintentional");
+                            },
+                            _ => ()
+                        }
+                    },
+                    _ => {
+                        let t = ty::expr_ty(cx.tcx, expr);
+                        match ty::get(t).sty {
+                            ty::ty_uint(_) => {
+                                cx.span_lint(lint::UnsignedNegate, e.span,
+                                             "negation of unsigned int variable may \
+                                             be unintentional");
+                            },
+                            _ => ()
+                        }
+                    }
+                };
+                // propagate negation, if the negation itself isn't negated
+                if self.negated_expr_id != e.id {
+                    self.negated_expr_id = expr.id;
+                }
+            },
+            ast::ExprParen(expr) if self.negated_expr_id == e.id => {
+                self.negated_expr_id = expr.id;
+            },
+            ast::ExprBinary(binop, l, r) => {
+                if is_comparison(binop) && !check_limits(cx.tcx, binop, l, r) {
+                    cx.span_lint(lint::TypeLimits, e.span,
+                                 "comparison is useless due to type limits");
+                }
+            },
+            ast::ExprLit(lit) => {
+                match ty::get(ty::expr_ty(cx.tcx, e)).sty {
+                    ty::ty_int(t) => {
+                        let int_type = if t == ast::TyI {
+                            cx.tcx.sess.targ_cfg.int_type
+                        } else { t };
+                        let (min, max) = int_ty_range(int_type);
+                        let mut lit_val: i64 = match lit.node {
+                            ast::LitInt(v, _) => v,
+                            ast::LitUint(v, _) => v as i64,
+                            ast::LitIntUnsuffixed(v) => v,
+                            _ => fail!()
+                        };
+                        if self.negated_expr_id == e.id {
+                            lit_val *= -1;
+                        }
+                        if  lit_val < min || lit_val > max {
+                            cx.span_lint(lint::TypeOverflow, e.span,
+                                         "literal out of range for its type");
+                        }
+                    },
+                    ty::ty_uint(t) => {
+                        let uint_type = if t == ast::TyU {
+                            cx.tcx.sess.targ_cfg.uint_type
+                        } else { t };
+                        let (min, max) = uint_ty_range(uint_type);
+                        let lit_val: u64 = match lit.node {
+                            ast::LitInt(v, _) => v as u64,
+                            ast::LitUint(v, _) => v,
+                            ast::LitIntUnsuffixed(v) => v as u64,
+                            _ => fail!()
+                        };
+                        if  lit_val < min || lit_val > max {
+                            cx.span_lint(lint::TypeOverflow, e.span,
+                                         "literal out of range for its type");
+                        }
+                    },
+
+                    _ => ()
+                };
+            },
+            _ => ()
+        };
+
+        fn is_valid<T:cmp::PartialOrd>(binop: ast::BinOp, v: T,
+                                min: T, max: T) -> bool {
+            match binop {
+                ast::BiLt => v >  min && v <= max,
+                ast::BiLe => v >= min && v <  max,
+                ast::BiGt => v >= min && v <  max,
+                ast::BiGe => v >  min && v <= max,
+                ast::BiEq | ast::BiNe => v >= min && v <= max,
+                _ => fail!()
+            }
+        }
+
+        fn rev_binop(binop: ast::BinOp) -> ast::BinOp {
+            match binop {
+                ast::BiLt => ast::BiGt,
+                ast::BiLe => ast::BiGe,
+                ast::BiGt => ast::BiLt,
+                ast::BiGe => ast::BiLe,
+                _ => binop
+            }
+        }
+
+        // for int & uint, be conservative with the warnings, so that the
+        // warnings are consistent between 32- and 64-bit platforms
+        fn int_ty_range(int_ty: ast::IntTy) -> (i64, i64) {
+            match int_ty {
+                ast::TyI =>    (i64::MIN,        i64::MAX),
+                ast::TyI8 =>   (i8::MIN  as i64, i8::MAX  as i64),
+                ast::TyI16 =>  (i16::MIN as i64, i16::MAX as i64),
+                ast::TyI32 =>  (i32::MIN as i64, i32::MAX as i64),
+                ast::TyI64 =>  (i64::MIN,        i64::MAX)
+            }
+        }
+
+        fn uint_ty_range(uint_ty: ast::UintTy) -> (u64, u64) {
+            match uint_ty {
+                ast::TyU =>   (u64::MIN,         u64::MAX),
+                ast::TyU8 =>  (u8::MIN   as u64, u8::MAX   as u64),
+                ast::TyU16 => (u16::MIN  as u64, u16::MAX  as u64),
+                ast::TyU32 => (u32::MIN  as u64, u32::MAX  as u64),
+                ast::TyU64 => (u64::MIN,         u64::MAX)
+            }
+        }
+
+        fn check_limits(tcx: &ty::ctxt, binop: ast::BinOp,
+                        l: &ast::Expr, r: &ast::Expr) -> bool {
+            let (lit, expr, swap) = match (&l.node, &r.node) {
+                (&ast::ExprLit(_), _) => (l, r, true),
+                (_, &ast::ExprLit(_)) => (r, l, false),
+                _ => return true
             };
-            t
-        });
-
-        if n_uniq > 0 && lint != lint::ManagedHeapMemory {
-            let s = ty_to_str(cx.tcx, ty);
-            let m = format!("type uses owned (Box type) pointers: {}", s);
-            cx.span_lint(lint, span, m.as_slice());
+            // Normalize the binop so that the literal is always on the RHS in
+            // the comparison
+            let norm_binop = if swap { rev_binop(binop) } else { binop };
+            match ty::get(ty::expr_ty(tcx, expr)).sty {
+                ty::ty_int(int_ty) => {
+                    let (min, max) = int_ty_range(int_ty);
+                    let lit_val: i64 = match lit.node {
+                        ast::ExprLit(li) => match li.node {
+                            ast::LitInt(v, _) => v,
+                            ast::LitUint(v, _) => v as i64,
+                            ast::LitIntUnsuffixed(v) => v,
+                            _ => return true
+                        },
+                        _ => fail!()
+                    };
+                    is_valid(norm_binop, lit_val, min, max)
+                }
+                ty::ty_uint(uint_ty) => {
+                    let (min, max): (u64, u64) = uint_ty_range(uint_ty);
+                    let lit_val: u64 = match lit.node {
+                        ast::ExprLit(li) => match li.node {
+                            ast::LitInt(v, _) => v as u64,
+                            ast::LitUint(v, _) => v,
+                            ast::LitIntUnsuffixed(v) => v as u64,
+                            _ => return true
+                        },
+                        _ => fail!()
+                    };
+                    is_valid(norm_binop, lit_val, min, max)
+                }
+                _ => true
+            }
         }
 
-        if n_box > 0 && lint != lint::OwnedHeapMemory {
-            let s = ty_to_str(cx.tcx, ty);
-            let m = format!("type uses managed (@ type) pointers: {}", s);
-            cx.span_lint(lint, span, m.as_slice());
+        fn is_comparison(binop: ast::BinOp) -> bool {
+            match binop {
+                ast::BiEq | ast::BiLt | ast::BiLe |
+                ast::BiNe | ast::BiGe | ast::BiGt => true,
+                _ => false
+            }
         }
     }
 }
 
-pub fn check_heap_item(cx: &Context, it: &ast::Item) {
-    match it.node {
-        ast::ItemFn(..) |
-        ast::ItemTy(..) |
-        ast::ItemEnum(..) |
-        ast::ItemStruct(..) => check_heap_type(cx, it.span,
-                                               ty::node_id_to_type(cx.tcx,
-                                                                   it.id)),
-        _ => ()
-    }
+#[deriving(Default)]
+pub struct CTypes;
 
-    // If it's a struct, we also have to check the fields' types
-    match it.node {
-        ast::ItemStruct(struct_def, _) => {
-            for struct_field in struct_def.fields.iter() {
-                check_heap_type(cx, struct_field.span,
-                                ty::node_id_to_type(cx.tcx,
-                                                    struct_field.node.id));
+impl LintPass for CTypes {
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        fn check_ty(cx: &Context, ty: &ast::Ty) {
+            match ty.node {
+                ast::TyPath(_, _, id) => {
+                    match cx.tcx.def_map.borrow().get_copy(&id) {
+                        def::DefPrimTy(ast::TyInt(ast::TyI)) => {
+                            cx.span_lint(lint::CTypes, ty.span,
+                                    "found rust type `int` in foreign module, while \
+                                    libc::c_int or libc::c_long should be used");
+                        }
+                        def::DefPrimTy(ast::TyUint(ast::TyU)) => {
+                            cx.span_lint(lint::CTypes, ty.span,
+                                    "found rust type `uint` in foreign module, while \
+                                    libc::c_uint or libc::c_ulong should be used");
+                        }
+                        def::DefTy(def_id) => {
+                            if !adt::is_ffi_safe(cx.tcx, def_id) {
+                                cx.span_lint(lint::CTypes, ty.span,
+                                             "found enum type without foreign-function-safe \
+                                              representation annotation in foreign module");
+                                // hmm... this message could be more helpful
+                            }
+                        }
+                        _ => ()
+                    }
+                }
+                ast::TyPtr(ref mt) => { check_ty(cx, mt.ty) }
+                _ => {}
             }
         }
-        _ => ()
+
+        fn check_foreign_fn(cx: &Context, decl: &ast::FnDecl) {
+            for input in decl.inputs.iter() {
+                check_ty(cx, input.ty);
+            }
+            check_ty(cx, decl.output)
+        }
+
+        match it.node {
+          ast::ItemForeignMod(ref nmod) if nmod.abi != abi::RustIntrinsic => {
+            for ni in nmod.items.iter() {
+                match ni.node {
+                    ast::ForeignItemFn(decl, _) => check_foreign_fn(cx, decl),
+                    ast::ForeignItemStatic(t, _) => check_ty(cx, t)
+                }
+            }
+          }
+          _ => {/* nothing to do */ }
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct HeapMemory;
+
+impl HeapMemory {
+    fn check_heap_type(&self, cx: &Context, span: Span, ty: ty::t) {
+        let xs = [lint::ManagedHeapMemory, lint::OwnedHeapMemory, lint::HeapMemory];
+        for &lint in xs.iter() {
+            if cx.get_level(lint) == lint::Allow { continue }
+
+            let mut n_box = 0;
+            let mut n_uniq = 0;
+            ty::fold_ty(cx.tcx, ty, |t| {
+                match ty::get(t).sty {
+                    ty::ty_box(_) => {
+                        n_box += 1;
+                    }
+                    ty::ty_uniq(_) |
+                    ty::ty_trait(box ty::TyTrait {
+                        store: ty::UniqTraitStore, ..
+                    }) |
+                    ty::ty_closure(box ty::ClosureTy {
+                        store: ty::UniqTraitStore,
+                        ..
+                    }) => {
+                        n_uniq += 1;
+                    }
+
+                    _ => ()
+                };
+                t
+            });
+
+            if n_uniq > 0 && lint != lint::ManagedHeapMemory {
+                let s = ty_to_str(cx.tcx, ty);
+                let m = format!("type uses owned (Box type) pointers: {}", s);
+                cx.span_lint(lint, span, m.as_slice());
+            }
+
+            if n_box > 0 && lint != lint::OwnedHeapMemory {
+                let s = ty_to_str(cx.tcx, ty);
+                let m = format!("type uses managed (@ type) pointers: {}", s);
+                cx.span_lint(lint, span, m.as_slice());
+            }
+        }
+    }
+}
+
+impl LintPass for HeapMemory {
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        match it.node {
+            ast::ItemFn(..) |
+            ast::ItemTy(..) |
+            ast::ItemEnum(..) |
+            ast::ItemStruct(..) => self.check_heap_type(cx, it.span,
+                                                        ty::node_id_to_type(cx.tcx,
+                                                                            it.id)),
+            _ => ()
+        }
+
+        // If it's a struct, we also have to check the fields' types
+        match it.node {
+            ast::ItemStruct(struct_def, _) => {
+                for struct_field in struct_def.fields.iter() {
+                    self.check_heap_type(cx, struct_field.span,
+                                         ty::node_id_to_type(cx.tcx,
+                                                             struct_field.node.id));
+                }
+            }
+            _ => ()
+        }
+    }
+
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        let ty = ty::expr_ty(cx.tcx, e);
+        self.check_heap_type(cx, e.span, ty);
     }
 }
 
@@ -367,7 +438,7 @@ struct RawPtrDerivingVisitor<'a> {
     cx: &'a Context<'a>
 }
 
-impl<'a> Visitor<()> for RawPtrDerivingVisitor<'a> {
+impl<'a> visit::Visitor<()> for RawPtrDerivingVisitor<'a> {
     fn visit_ty(&mut self, ty: &ast::Ty, _: ()) {
         static MSG: &'static str = "use of `#[deriving]` with a raw pointer";
         match ty.node {
@@ -381,450 +452,608 @@ impl<'a> Visitor<()> for RawPtrDerivingVisitor<'a> {
     fn visit_block(&mut self, _: &ast::Block, _: ()) {}
 }
 
-pub fn check_raw_ptr_deriving(cx: &mut Context, item: &ast::Item) {
-    if !attr::contains_name(item.attrs.as_slice(), "automatically_derived") {
-        return
-    }
-    let did = match item.node {
-        ast::ItemImpl(..) => {
-            match ty::get(ty::node_id_to_type(cx.tcx, item.id)).sty {
-                ty::ty_enum(did, _) => did,
-                ty::ty_struct(did, _) => did,
-                _ => return,
-            }
-        }
-        _ => return,
-    };
-    if !ast_util::is_local(did) { return }
-    let item = match cx.tcx.map.find(did.node) {
-        Some(ast_map::NodeItem(item)) => item,
-        _ => return,
-    };
-    if !cx.checked_raw_pointers.insert(item.id) { return }
-    match item.node {
-        ast::ItemStruct(..) | ast::ItemEnum(..) => {
-            let mut visitor = RawPtrDerivingVisitor { cx: cx };
-            visit::walk_item(&mut visitor, item, ());
-        }
-        _ => {}
-    }
+pub struct RawPointerDeriving {
+    checked_raw_pointers: NodeSet,
 }
 
-pub fn check_unused_attribute(cx: &Context, attr: &ast::Attribute) {
-    static ATTRIBUTE_WHITELIST: &'static [&'static str] = &'static [
-        // FIXME: #14408 whitelist docs since rustdoc looks at them
-        "doc",
-
-        // FIXME: #14406 these are processed in trans, which happens after the
-        // lint pass
-        "address_insignificant",
-        "cold",
-        "inline",
-        "link",
-        "link_name",
-        "link_section",
-        "no_builtins",
-        "no_mangle",
-        "no_split_stack",
-        "packed",
-        "static_assert",
-        "thread_local",
-
-        // not used anywhere (!?) but apparently we want to keep them around
-        "comment",
-        "desc",
-        "license",
-
-        // FIXME: #14407 these are only looked at on-demand so we can't
-        // guarantee they'll have already been checked
-        "deprecated",
-        "experimental",
-        "frozen",
-        "locked",
-        "must_use",
-        "stable",
-        "unstable",
-    ];
-
-    static CRATE_ATTRS: &'static [&'static str] = &'static [
-        "crate_type",
-        "feature",
-        "no_start",
-        "no_main",
-        "no_std",
-        "crate_id",
-        "desc",
-        "comment",
-        "license",
-        "copyright",
-        "no_builtins",
-    ];
-
-    for &name in ATTRIBUTE_WHITELIST.iter() {
-        if attr.check_name(name) {
-            break;
-        }
-    }
-
-    if !attr::is_used(attr) {
-        cx.span_lint(lint::UnusedAttribute, attr.span, "unused attribute");
-        if CRATE_ATTRS.contains(&attr.name().get()) {
-            let msg = match attr.node.style {
-               ast::AttrOuter => "crate-level attribute should be an inner \
-                                  attribute: add an exclamation mark: #![foo]",
-                ast::AttrInner => "crate-level attribute should be in the \
-                                   root module",
-            };
-            cx.span_lint(lint::UnusedAttribute, attr.span, msg);
+impl Default for RawPointerDeriving {
+    fn default() -> RawPointerDeriving {
+        RawPointerDeriving {
+            checked_raw_pointers: NodeSet::new(),
         }
     }
 }
 
-pub fn check_heap_expr(cx: &Context, e: &ast::Expr) {
-    let ty = ty::expr_ty(cx.tcx, e);
-    check_heap_type(cx, e.span, ty);
-}
-
-pub fn check_path_statement(cx: &Context, s: &ast::Stmt) {
-    match s.node {
-        ast::StmtSemi(expr, _) => {
-            match expr.node {
-                ast::ExprPath(_) => {
-                    cx.span_lint(lint::PathStatement,
-                                 s.span,
-                                 "path statement with no effect");
+impl LintPass for RawPointerDeriving {
+    fn check_item(&mut self, cx: &Context, item: &ast::Item) {
+        if !attr::contains_name(item.attrs.as_slice(), "automatically_derived") {
+            return
+        }
+        let did = match item.node {
+            ast::ItemImpl(..) => {
+                match ty::get(ty::node_id_to_type(cx.tcx, item.id)).sty {
+                    ty::ty_enum(did, _) => did,
+                    ty::ty_struct(did, _) => did,
+                    _ => return,
                 }
-                _ => {}
             }
+            _ => return,
+        };
+        if !ast_util::is_local(did) { return }
+        let item = match cx.tcx.map.find(did.node) {
+            Some(ast_map::NodeItem(item)) => item,
+            _ => return,
+        };
+        if !self.checked_raw_pointers.insert(item.id) { return }
+        match item.node {
+            ast::ItemStruct(..) | ast::ItemEnum(..) => {
+                let mut visitor = RawPtrDerivingVisitor { cx: cx };
+                visit::walk_item(&mut visitor, item, ());
+            }
+            _ => {}
         }
-        _ => ()
     }
 }
 
-pub fn check_unused_result(cx: &Context, s: &ast::Stmt) {
-    let expr = match s.node {
-        ast::StmtSemi(expr, _) => expr,
-        _ => return
-    };
-    let t = ty::expr_ty(cx.tcx, expr);
-    match ty::get(t).sty {
-        ty::ty_nil | ty::ty_bot | ty::ty_bool => return,
-        _ => {}
-    }
-    match expr.node {
-        ast::ExprRet(..) => return,
-        _ => {}
-    }
+#[deriving(Default)]
+pub struct UnusedAttribute;
 
-    let t = ty::expr_ty(cx.tcx, expr);
-    let mut warned = false;
-    match ty::get(t).sty {
-        ty::ty_struct(did, _) |
-        ty::ty_enum(did, _) => {
-            if ast_util::is_local(did) {
-                match cx.tcx.map.get(did.node) {
-                    ast_map::NodeItem(it) => {
-                        if attr::contains_name(it.attrs.as_slice(),
-                                               "must_use") {
+impl LintPass for UnusedAttribute {
+    fn check_attribute(&mut self, cx: &Context, attr: &ast::Attribute) {
+        static ATTRIBUTE_WHITELIST: &'static [&'static str] = &'static [
+            // FIXME: #14408 whitelist docs since rustdoc looks at them
+            "doc",
+
+            // FIXME: #14406 these are processed in trans, which happens after the
+            // lint pass
+            "address_insignificant",
+            "cold",
+            "inline",
+            "link",
+            "link_name",
+            "link_section",
+            "no_builtins",
+            "no_mangle",
+            "no_split_stack",
+            "packed",
+            "static_assert",
+            "thread_local",
+
+            // not used anywhere (!?) but apparently we want to keep them around
+            "comment",
+            "desc",
+            "license",
+
+            // FIXME: #14407 these are only looked at on-demand so we can't
+            // guarantee they'll have already been checked
+            "deprecated",
+            "experimental",
+            "frozen",
+            "locked",
+            "must_use",
+            "stable",
+            "unstable",
+        ];
+
+        static CRATE_ATTRS: &'static [&'static str] = &'static [
+            "crate_type",
+            "feature",
+            "no_start",
+            "no_main",
+            "no_std",
+            "crate_id",
+            "desc",
+            "comment",
+            "license",
+            "copyright",
+            "no_builtins",
+        ];
+
+        for &name in ATTRIBUTE_WHITELIST.iter() {
+            if attr.check_name(name) {
+                break;
+            }
+        }
+
+        if !attr::is_used(attr) {
+            cx.span_lint(lint::UnusedAttribute, attr.span, "unused attribute");
+            if CRATE_ATTRS.contains(&attr.name().get()) {
+                let msg = match attr.node.style {
+                   ast::AttrOuter => "crate-level attribute should be an inner \
+                                      attribute: add an exclamation mark: #![foo]",
+                    ast::AttrInner => "crate-level attribute should be in the \
+                                       root module",
+                };
+                cx.span_lint(lint::UnusedAttribute, attr.span, msg);
+            }
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct PathStatement;
+
+impl LintPass for PathStatement {
+    fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
+        match s.node {
+            ast::StmtSemi(expr, _) => {
+                match expr.node {
+                    ast::ExprPath(_) => {
+                        cx.span_lint(lint::PathStatement,
+                                     s.span,
+                                     "path statement with no effect");
+                    }
+                    _ => {}
+                }
+            }
+            _ => ()
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct UnusedMustUse;
+
+impl LintPass for UnusedMustUse {
+    fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
+        let expr = match s.node {
+            ast::StmtSemi(expr, _) => expr,
+            _ => return
+        };
+        let t = ty::expr_ty(cx.tcx, expr);
+        match ty::get(t).sty {
+            ty::ty_nil | ty::ty_bot | ty::ty_bool => return,
+            _ => {}
+        }
+        match expr.node {
+            ast::ExprRet(..) => return,
+            _ => {}
+        }
+
+        let t = ty::expr_ty(cx.tcx, expr);
+        let mut warned = false;
+        match ty::get(t).sty {
+            ty::ty_struct(did, _) |
+            ty::ty_enum(did, _) => {
+                if ast_util::is_local(did) {
+                    match cx.tcx.map.get(did.node) {
+                        ast_map::NodeItem(it) => {
+                            if attr::contains_name(it.attrs.as_slice(),
+                                                   "must_use") {
+                                cx.span_lint(lint::UnusedMustUse, s.span,
+                                             "unused result which must be used");
+                                warned = true;
+                            }
+                        }
+                        _ => {}
+                    }
+                } else {
+                    csearch::get_item_attrs(&cx.tcx.sess.cstore, did, |attrs| {
+                        if attr::contains_name(attrs.as_slice(), "must_use") {
                             cx.span_lint(lint::UnusedMustUse, s.span,
                                          "unused result which must be used");
                             warned = true;
                         }
+                    });
+                }
+            }
+            _ => {}
+        }
+        if !warned {
+            cx.span_lint(lint::UnusedResult, s.span, "unused result");
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct DeprecatedOwnedVector;
+
+impl LintPass for DeprecatedOwnedVector {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        let t = ty::expr_ty(cx.tcx, e);
+        match ty::get(t).sty {
+            ty::ty_uniq(t) => match ty::get(t).sty {
+                ty::ty_vec(_, None) => {
+                    cx.span_lint(lint::DeprecatedOwnedVector, e.span,
+                                 "use of deprecated `~[]` vector; replaced by `std::vec::Vec`")
+                }
+                _ => {}
+            },
+            _ => {}
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct NonCamelCaseTypes;
+
+impl LintPass for NonCamelCaseTypes {
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        fn is_camel_case(ident: ast::Ident) -> bool {
+            let ident = token::get_ident(ident);
+            assert!(!ident.get().is_empty());
+            let ident = ident.get().trim_chars('_');
+
+            // start with a non-lowercase letter rather than non-uppercase
+            // ones (some scripts don't have a concept of upper/lowercase)
+            !ident.char_at(0).is_lowercase() && !ident.contains_char('_')
+        }
+
+        fn to_camel_case(s: &str) -> String {
+            s.split('_').flat_map(|word| word.chars().enumerate().map(|(i, c)|
+                if i == 0 { c.to_uppercase() }
+                else { c }
+            )).collect()
+        }
+
+        fn check_case(cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
+            let s = token::get_ident(ident);
+
+            if !is_camel_case(ident) {
+                cx.span_lint(lint::
+                    NonCamelCaseTypes, span,
+                    format!("{} `{}` should have a camel case name such as `{}`",
+                        sort, s, to_camel_case(s.get())).as_slice());
+            }
+        }
+
+        match it.node {
+            ast::ItemTy(..) | ast::ItemStruct(..) => {
+                check_case(cx, "type", it.ident, it.span)
+            }
+            ast::ItemTrait(..) => {
+                check_case(cx, "trait", it.ident, it.span)
+            }
+            ast::ItemEnum(ref enum_definition, _) => {
+                check_case(cx, "type", it.ident, it.span);
+                for variant in enum_definition.variants.iter() {
+                    check_case(cx, "variant", variant.node.name, variant.span);
+                }
+            }
+            _ => ()
+        }
+    }
+}
+
+#[deriving(PartialEq)]
+enum MethodContext {
+    TraitDefaultImpl,
+    TraitImpl,
+    PlainImpl
+}
+
+fn method_context(cx: &Context, m: &ast::Method) -> MethodContext {
+    let did = ast::DefId {
+        krate: ast::LOCAL_CRATE,
+        node: m.id
+    };
+
+    match cx.tcx.methods.borrow().find_copy(&did) {
+        None => cx.tcx.sess.span_bug(m.span, "missing method descriptor?!"),
+        Some(md) => {
+            match md.container {
+                ty::TraitContainer(..) => TraitDefaultImpl,
+                ty::ImplContainer(cid) => {
+                    match ty::impl_trait_ref(cx.tcx, cid) {
+                        Some(..) => TraitImpl,
+                        None => PlainImpl
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct NonSnakeCaseFunctions;
+
+impl NonSnakeCaseFunctions {
+    fn check_snake_case(&self, cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
+        fn is_snake_case(ident: ast::Ident) -> bool {
+            let ident = token::get_ident(ident);
+            assert!(!ident.get().is_empty());
+            let ident = ident.get().trim_chars('_');
+
+            let mut allow_underscore = true;
+            ident.chars().all(|c| {
+                allow_underscore = match c {
+                    c if c.is_lowercase() || c.is_digit() => true,
+                    '_' if allow_underscore => false,
+                    _ => return false,
+                };
+                true
+            })
+        }
+
+        fn to_snake_case(str: &str) -> String {
+            let mut words = vec![];
+            for s in str.split('_') {
+                let mut buf = String::new();
+                if s.is_empty() { continue; }
+                for ch in s.chars() {
+                    if !buf.is_empty() && ch.is_uppercase() {
+                        words.push(buf);
+                        buf = String::new();
+                    }
+                    buf.push_char(ch.to_lowercase());
+                }
+                words.push(buf);
+            }
+            words.connect("_")
+        }
+
+        let s = token::get_ident(ident);
+
+        if !is_snake_case(ident) {
+            cx.span_lint(lint::NonSnakeCaseFunctions, span,
+                format!("{} `{}` should have a snake case name such as `{}`",
+                    sort, s, to_snake_case(s.get())).as_slice());
+        }
+    }
+}
+
+impl LintPass for NonSnakeCaseFunctions {
+    fn check_fn(&mut self, cx: &Context,
+                fk: &visit::FnKind, _: &ast::FnDecl,
+                _: &ast::Block, span: Span, _: ast::NodeId) {
+        match *fk {
+            visit::FkMethod(ident, _, m) => match method_context(cx, m) {
+                PlainImpl
+                    => self.check_snake_case(cx, "method", ident, span),
+                TraitDefaultImpl
+                    => self.check_snake_case(cx, "trait method", ident, span),
+                _ => (),
+            },
+            visit::FkItemFn(ident, _, _, _)
+                => self.check_snake_case(cx, "function", ident, span),
+            _ => (),
+        }
+    }
+
+    fn check_ty_method(&mut self, cx: &Context, t: &ast::TypeMethod) {
+        self.check_snake_case(cx, "trait method", t.ident, t.span);
+    }
+}
+
+#[deriving(Default)]
+pub struct NonUppercaseStatics;
+
+impl LintPass for NonUppercaseStatics {
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        match it.node {
+            // only check static constants
+            ast::ItemStatic(_, ast::MutImmutable, _) => {
+                let s = token::get_ident(it.ident);
+                // check for lowercase letters rather than non-uppercase
+                // ones (some scripts don't have a concept of
+                // upper/lowercase)
+                if s.get().chars().any(|c| c.is_lowercase()) {
+                    cx.span_lint(lint::NonUppercaseStatics, it.span,
+                        format!("static constant `{}` should have an uppercase name \
+                            such as `{}`", s.get(),
+                            s.get().chars().map(|c| c.to_uppercase())
+                                .collect::<String>().as_slice()).as_slice());
+                }
+            }
+            _ => {}
+        }
+    }
+
+    fn check_pat(&mut self, cx: &Context, p: &ast::Pat) {
+        // Lint for constants that look like binding identifiers (#7526)
+        match (&p.node, cx.tcx.def_map.borrow().find(&p.id)) {
+            (&ast::PatIdent(_, ref path, _), Some(&def::DefStatic(_, false))) => {
+                // last identifier alone is right choice for this lint.
+                let ident = path.segments.last().unwrap().identifier;
+                let s = token::get_ident(ident);
+                if s.get().chars().any(|c| c.is_lowercase()) {
+                    cx.span_lint(lint::NonUppercasePatternStatics, path.span,
+                        format!("static constant in pattern `{}` should have an uppercase \
+                            name such as `{}`", s.get(),
+                            s.get().chars().map(|c| c.to_uppercase())
+                                .collect::<String>().as_slice()).as_slice());
+                }
+            }
+            _ => {}
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct UppercaseVariables;
+
+impl LintPass for UppercaseVariables {
+    fn check_pat(&mut self, cx: &Context, p: &ast::Pat) {
+        match &p.node {
+            &ast::PatIdent(_, ref path, _) => {
+                match cx.tcx.def_map.borrow().find(&p.id) {
+                    Some(&def::DefLocal(_, _)) | Some(&def::DefBinding(_, _)) |
+                            Some(&def::DefArg(_, _)) => {
+                        // last identifier alone is right choice for this lint.
+                        let ident = path.segments.last().unwrap().identifier;
+                        let s = token::get_ident(ident);
+                        if s.get().len() > 0 && s.get().char_at(0).is_uppercase() {
+                            cx.span_lint(lint::
+                                UppercaseVariables,
+                                path.span,
+                                "variable names should start with a lowercase character");
+                        }
                     }
                     _ => {}
                 }
-            } else {
-                csearch::get_item_attrs(&cx.tcx.sess.cstore, did, |attrs| {
-                    if attr::contains_name(attrs.as_slice(), "must_use") {
-                        cx.span_lint(lint::UnusedMustUse, s.span,
-                                     "unused result which must be used");
-                        warned = true;
-                    }
-                });
-            }
-        }
-        _ => {}
-    }
-    if !warned {
-        cx.span_lint(lint::UnusedResult, s.span, "unused result");
-    }
-}
-
-pub fn check_deprecated_owned_vector(cx: &Context, e: &ast::Expr) {
-    let t = ty::expr_ty(cx.tcx, e);
-    match ty::get(t).sty {
-        ty::ty_uniq(t) => match ty::get(t).sty {
-            ty::ty_vec(_, None) => {
-                cx.span_lint(lint::DeprecatedOwnedVector, e.span,
-                             "use of deprecated `~[]` vector; replaced by `std::vec::Vec`")
             }
             _ => {}
-        },
-        _ => {}
-    }
-}
-
-pub fn check_item_non_camel_case_types(cx: &Context, it: &ast::Item) {
-    fn is_camel_case(ident: ast::Ident) -> bool {
-        let ident = token::get_ident(ident);
-        assert!(!ident.get().is_empty());
-        let ident = ident.get().trim_chars('_');
-
-        // start with a non-lowercase letter rather than non-uppercase
-        // ones (some scripts don't have a concept of upper/lowercase)
-        !ident.char_at(0).is_lowercase() && !ident.contains_char('_')
-    }
-
-    fn to_camel_case(s: &str) -> String {
-        s.split('_').flat_map(|word| word.chars().enumerate().map(|(i, c)|
-            if i == 0 { c.to_uppercase() }
-            else { c }
-        )).collect()
-    }
-
-    fn check_case(cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
-        let s = token::get_ident(ident);
-
-        if !is_camel_case(ident) {
-            cx.span_lint(lint::
-                NonCamelCaseTypes, span,
-                format!("{} `{}` should have a camel case name such as `{}`",
-                    sort, s, to_camel_case(s.get())).as_slice());
         }
     }
 
-    match it.node {
-        ast::ItemTy(..) | ast::ItemStruct(..) => {
-            check_case(cx, "type", it.ident, it.span)
-        }
-        ast::ItemTrait(..) => {
-            check_case(cx, "trait", it.ident, it.span)
-        }
-        ast::ItemEnum(ref enum_definition, _) => {
-            check_case(cx, "type", it.ident, it.span);
-            for variant in enum_definition.variants.iter() {
-                check_case(cx, "variant", variant.node.name, variant.span);
-            }
-        }
-        _ => ()
-    }
-}
-
-pub fn check_snake_case(cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
-    fn is_snake_case(ident: ast::Ident) -> bool {
-        let ident = token::get_ident(ident);
-        assert!(!ident.get().is_empty());
-        let ident = ident.get().trim_chars('_');
-
-        let mut allow_underscore = true;
-        ident.chars().all(|c| {
-            allow_underscore = match c {
-                c if c.is_lowercase() || c.is_digit() => true,
-                '_' if allow_underscore => false,
-                _ => return false,
-            };
-            true
-        })
-    }
-
-    fn to_snake_case(str: &str) -> String {
-        let mut words = vec![];
-        for s in str.split('_') {
-            let mut buf = String::new();
-            if s.is_empty() { continue; }
-            for ch in s.chars() {
-                if !buf.is_empty() && ch.is_uppercase() {
-                    words.push(buf);
-                    buf = String::new();
-                }
-                buf.push_char(ch.to_lowercase());
-            }
-            words.push(buf);
-        }
-        words.connect("_")
-    }
-
-    let s = token::get_ident(ident);
-
-    if !is_snake_case(ident) {
-        cx.span_lint(lint::NonSnakeCaseFunctions, span,
-            format!("{} `{}` should have a snake case name such as `{}`",
-                sort, s, to_snake_case(s.get())).as_slice());
-    }
-}
-
-pub fn check_item_non_uppercase_statics(cx: &Context, it: &ast::Item) {
-    match it.node {
-        // only check static constants
-        ast::ItemStatic(_, ast::MutImmutable, _) => {
-            let s = token::get_ident(it.ident);
-            // check for lowercase letters rather than non-uppercase
-            // ones (some scripts don't have a concept of
-            // upper/lowercase)
-            if s.get().chars().any(|c| c.is_lowercase()) {
-                cx.span_lint(lint::NonUppercaseStatics, it.span,
-                    format!("static constant `{}` should have an uppercase name \
-                        such as `{}`", s.get(),
-                        s.get().chars().map(|c| c.to_uppercase())
-                            .collect::<String>().as_slice()).as_slice());
-            }
-        }
-        _ => {}
-    }
-}
-
-pub fn check_pat_non_uppercase_statics(cx: &Context, p: &ast::Pat) {
-    // Lint for constants that look like binding identifiers (#7526)
-    match (&p.node, cx.tcx.def_map.borrow().find(&p.id)) {
-        (&ast::PatIdent(_, ref path, _), Some(&def::DefStatic(_, false))) => {
-            // last identifier alone is right choice for this lint.
-            let ident = path.segments.last().unwrap().identifier;
-            let s = token::get_ident(ident);
-            if s.get().chars().any(|c| c.is_lowercase()) {
-                cx.span_lint(lint::NonUppercasePatternStatics, path.span,
-                    format!("static constant in pattern `{}` should have an uppercase \
-                        name such as `{}`", s.get(),
-                        s.get().chars().map(|c| c.to_uppercase())
-                            .collect::<String>().as_slice()).as_slice());
-            }
-        }
-        _ => {}
-    }
-}
-
-pub fn check_pat_uppercase_variable(cx: &Context, p: &ast::Pat) {
-    match &p.node {
-        &ast::PatIdent(_, ref path, _) => {
-            match cx.tcx.def_map.borrow().find(&p.id) {
-                Some(&def::DefLocal(_, _)) | Some(&def::DefBinding(_, _)) |
-                        Some(&def::DefArg(_, _)) => {
-                    // last identifier alone is right choice for this lint.
-                    let ident = path.segments.last().unwrap().identifier;
+    fn check_struct_def(&mut self, cx: &Context, s: &ast::StructDef,
+            _: ast::Ident, _: &ast::Generics, _: ast::NodeId) {
+        for sf in s.fields.iter() {
+            match sf.node {
+                ast::StructField_ { kind: ast::NamedField(ident, _), .. } => {
                     let s = token::get_ident(ident);
-                    if s.get().len() > 0 && s.get().char_at(0).is_uppercase() {
-                        cx.span_lint(lint::
-                            UppercaseVariables,
-                            path.span,
-                            "variable names should start with a lowercase character");
+                    if s.get().char_at(0).is_uppercase() {
+                        cx.span_lint(lint::UppercaseVariables,
+                            sf.span,
+                            "structure field names should start with a lowercase character");
                     }
                 }
                 _ => {}
             }
         }
-        _ => {}
     }
 }
 
-pub fn check_struct_uppercase_variable(cx: &Context, s: &ast::StructDef) {
-    for sf in s.fields.iter() {
-        match sf.node {
-            ast::StructField_ { kind: ast::NamedField(ident, _), .. } => {
-                let s = token::get_ident(ident);
-                if s.get().char_at(0).is_uppercase() {
-                    cx.span_lint(lint::
-                        UppercaseVariables,
-                        sf.span,
-                        "structure field names should start with a lowercase character");
-                }
+#[deriving(Default)]
+pub struct UnnecessaryParens;
+
+impl UnnecessaryParens {
+    fn check_unnecessary_parens_core(&self, cx: &Context, value: &ast::Expr, msg: &str) {
+        match value.node {
+            ast::ExprParen(_) => {
+                cx.span_lint(lint::UnnecessaryParens, value.span,
+                             format!("unnecessary parentheses around {}",
+                                     msg).as_slice())
             }
             _ => {}
         }
     }
 }
 
-pub fn check_unnecessary_parens_core(cx: &Context, value: &ast::Expr, msg: &str) {
-    match value.node {
-        ast::ExprParen(_) => {
-            cx.span_lint(lint::UnnecessaryParens, value.span,
-                         format!("unnecessary parentheses around {}",
-                                 msg).as_slice())
-        }
-        _ => {}
+impl LintPass for UnnecessaryParens {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        let (value, msg) = match e.node {
+            ast::ExprIf(cond, _, _) => (cond, "`if` condition"),
+            ast::ExprWhile(cond, _) => (cond, "`while` condition"),
+            ast::ExprMatch(head, _) => (head, "`match` head expression"),
+            ast::ExprRet(Some(value)) => (value, "`return` value"),
+            ast::ExprAssign(_, value) => (value, "assigned value"),
+            ast::ExprAssignOp(_, _, value) => (value, "assigned value"),
+            _ => return
+        };
+        self.check_unnecessary_parens_core(cx, value, msg);
     }
-}
 
-pub fn check_unnecessary_parens_expr(cx: &Context, e: &ast::Expr) {
-    let (value, msg) = match e.node {
-        ast::ExprIf(cond, _, _) => (cond, "`if` condition"),
-        ast::ExprWhile(cond, _) => (cond, "`while` condition"),
-        ast::ExprMatch(head, _) => (head, "`match` head expression"),
-        ast::ExprRet(Some(value)) => (value, "`return` value"),
-        ast::ExprAssign(_, value) => (value, "assigned value"),
-        ast::ExprAssignOp(_, _, value) => (value, "assigned value"),
-        _ => return
-    };
-    check_unnecessary_parens_core(cx, value, msg);
-}
-
-pub fn check_unnecessary_parens_stmt(cx: &Context, s: &ast::Stmt) {
-    let (value, msg) = match s.node {
-        ast::StmtDecl(decl, _) => match decl.node {
-            ast::DeclLocal(local) => match local.init {
-                Some(value) => (value, "assigned value"),
-                None => return
+    fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
+        let (value, msg) = match s.node {
+            ast::StmtDecl(decl, _) => match decl.node {
+                ast::DeclLocal(local) => match local.init {
+                    Some(value) => (value, "assigned value"),
+                    None => return
+                },
+                _ => return
             },
             _ => return
-        },
-        _ => return
-    };
-    check_unnecessary_parens_core(cx, value, msg);
-}
-
-pub fn check_unused_unsafe(cx: &Context, e: &ast::Expr) {
-    match e.node {
-        // Don't warn about generated blocks, that'll just pollute the output.
-        ast::ExprBlock(ref blk) => {
-            if blk.rules == ast::UnsafeBlock(ast::UserProvided) &&
-                !cx.tcx.used_unsafe.borrow().contains(&blk.id) {
-                cx.span_lint(lint::UnusedUnsafe, blk.span,
-                             "unnecessary `unsafe` block");
-            }
-        }
-        _ => ()
+        };
+        self.check_unnecessary_parens_core(cx, value, msg);
     }
 }
 
-pub fn check_unsafe_block(cx: &Context, e: &ast::Expr) {
-    match e.node {
-        // Don't warn about generated blocks, that'll just pollute the output.
-        ast::ExprBlock(ref blk) if blk.rules == ast::UnsafeBlock(ast::UserProvided) => {
-            cx.span_lint(lint::UnsafeBlock, blk.span, "usage of an `unsafe` block");
-        }
-        _ => ()
-    }
-}
+#[deriving(Default)]
+pub struct UnusedUnsafe;
 
-pub fn check_unused_mut_pat(cx: &Context, pats: &[@ast::Pat]) {
-    // collect all mutable pattern and group their NodeIDs by their Identifier to
-    // avoid false warnings in match arms with multiple patterns
-    let mut mutables = HashMap::new();
-    for &p in pats.iter() {
-        pat_util::pat_bindings(&cx.tcx.def_map, p, |mode, id, _, path| {
-            match mode {
-                ast::BindByValue(ast::MutMutable) => {
-                    if path.segments.len() != 1 {
-                        cx.tcx.sess.span_bug(p.span,
-                                             "mutable binding that doesn't consist \
-                                              of exactly one segment");
-                    }
-                    let ident = path.segments.get(0).identifier;
-                    if !token::get_ident(ident).get().starts_with("_") {
-                        mutables.insert_or_update_with(ident.name as uint, vec!(id), |_, old| {
-                            old.push(id);
-                        });
-                    }
-                }
-                _ => {
+impl LintPass for UnusedUnsafe {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        match e.node {
+            // Don't warn about generated blocks, that'll just pollute the output.
+            ast::ExprBlock(ref blk) => {
+                if blk.rules == ast::UnsafeBlock(ast::UserProvided) &&
+                    !cx.tcx.used_unsafe.borrow().contains(&blk.id) {
+                    cx.span_lint(lint::UnusedUnsafe, blk.span,
+                                 "unnecessary `unsafe` block");
                 }
             }
-        });
+            _ => ()
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct UnsafeBlock;
+
+impl LintPass for UnsafeBlock {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        match e.node {
+            // Don't warn about generated blocks, that'll just pollute the output.
+            ast::ExprBlock(ref blk) if blk.rules == ast::UnsafeBlock(ast::UserProvided) => {
+                cx.span_lint(lint::UnsafeBlock, blk.span, "usage of an `unsafe` block");
+            }
+            _ => ()
+        }
+    }
+}
+
+#[deriving(Default)]
+pub struct UnusedMut;
+
+impl UnusedMut {
+    fn check_unused_mut_pat(&self, cx: &Context, pats: &[@ast::Pat]) {
+        // collect all mutable pattern and group their NodeIDs by their Identifier to
+        // avoid false warnings in match arms with multiple patterns
+        let mut mutables = HashMap::new();
+        for &p in pats.iter() {
+            pat_util::pat_bindings(&cx.tcx.def_map, p, |mode, id, _, path| {
+                match mode {
+                    ast::BindByValue(ast::MutMutable) => {
+                        if path.segments.len() != 1 {
+                            cx.tcx.sess.span_bug(p.span,
+                                                 "mutable binding that doesn't consist \
+                                                  of exactly one segment");
+                        }
+                        let ident = path.segments.get(0).identifier;
+                        if !token::get_ident(ident).get().starts_with("_") {
+                            mutables.insert_or_update_with(ident.name as uint, vec!(id), |_, old| {
+                                old.push(id);
+                            });
+                        }
+                    }
+                    _ => {
+                    }
+                }
+            });
+        }
+
+        let used_mutables = cx.tcx.used_mut_nodes.borrow();
+        for (_, v) in mutables.iter() {
+            if !v.iter().any(|e| used_mutables.contains(e)) {
+                cx.span_lint(lint::UnusedMut, cx.tcx.map.span(*v.get(0)),
+                             "variable does not need to be mutable");
+            }
+        }
+    }
+}
+
+impl LintPass for UnusedMut {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        match e.node {
+            ast::ExprMatch(_, ref arms) => {
+                for a in arms.iter() {
+                    self.check_unused_mut_pat(cx, a.pats.as_slice())
+                }
+            }
+            _ => {}
+        }
     }
 
-    let used_mutables = cx.tcx.used_mut_nodes.borrow();
-    for (_, v) in mutables.iter() {
-        if !v.iter().any(|e| used_mutables.contains(e)) {
-            cx.span_lint(lint::UnusedMut, cx.tcx.map.span(*v.get(0)),
-                         "variable does not need to be mutable");
+    fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
+        match s.node {
+            ast::StmtDecl(d, _) => {
+                match d.node {
+                    ast::DeclLocal(l) => {
+                        self.check_unused_mut_pat(cx, &[l.pat]);
+                    },
+                    _ => {}
+                }
+            },
+            _ => {}
+        }
+    }
+
+    fn check_fn(&mut self, cx: &Context,
+                _: &visit::FnKind, decl: &ast::FnDecl,
+                _: &ast::Block, _: Span, _: ast::NodeId) {
+        for a in decl.inputs.iter() {
+            self.check_unused_mut_pat(cx, &[a.pat]);
         }
     }
 }
@@ -834,248 +1063,302 @@ enum Allocation {
     BoxAllocation
 }
 
-pub fn check_unnecessary_allocation(cx: &Context, e: &ast::Expr) {
-    // Warn if string and vector literals with sigils, or boxing expressions,
-    // are immediately borrowed.
-    let allocation = match e.node {
-        ast::ExprVstore(e2, ast::ExprVstoreUniq) => {
-            match e2.node {
-                ast::ExprLit(lit) if ast_util::lit_is_str(lit) => {
-                    VectorAllocation
-                }
-                ast::ExprVec(..) => VectorAllocation,
-                _ => return
-            }
-        }
-        ast::ExprUnary(ast::UnUniq, _) |
-        ast::ExprUnary(ast::UnBox, _) => BoxAllocation,
+#[deriving(Default)]
+pub struct UnnecessaryAllocation;
 
-        _ => return
-    };
-
-    let report = |msg| {
-        cx.span_lint(lint::UnnecessaryAllocation, e.span, msg);
-    };
-
-    match cx.tcx.adjustments.borrow().find(&e.id) {
-        Some(adjustment) => {
-            match *adjustment {
-                ty::AutoDerefRef(ty::AutoDerefRef { autoref, .. }) => {
-                    match (allocation, autoref) {
-                        (VectorAllocation, Some(ty::AutoBorrowVec(..))) => {
-                            report("unnecessary allocation, the sigil can be \
-                                    removed");
-                        }
-                        (BoxAllocation,
-                         Some(ty::AutoPtr(_, ast::MutImmutable))) => {
-                            report("unnecessary allocation, use & instead");
-                        }
-                        (BoxAllocation,
-                         Some(ty::AutoPtr(_, ast::MutMutable))) => {
-                            report("unnecessary allocation, use &mut \
-                                    instead");
-                        }
-                        _ => ()
+impl LintPass for UnnecessaryAllocation {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        // Warn if string and vector literals with sigils, or boxing expressions,
+        // are immediately borrowed.
+        let allocation = match e.node {
+            ast::ExprVstore(e2, ast::ExprVstoreUniq) => {
+                match e2.node {
+                    ast::ExprLit(lit) if ast_util::lit_is_str(lit) => {
+                        VectorAllocation
                     }
+                    ast::ExprVec(..) => VectorAllocation,
+                    _ => return
                 }
-                _ => {}
             }
+            ast::ExprUnary(ast::UnUniq, _) |
+            ast::ExprUnary(ast::UnBox, _) => BoxAllocation,
+
+            _ => return
+        };
+
+        let report = |msg| {
+            cx.span_lint(lint::UnnecessaryAllocation, e.span, msg);
+        };
+
+        match cx.tcx.adjustments.borrow().find(&e.id) {
+            Some(adjustment) => {
+                match *adjustment {
+                    ty::AutoDerefRef(ty::AutoDerefRef { autoref, .. }) => {
+                        match (allocation, autoref) {
+                            (VectorAllocation, Some(ty::AutoBorrowVec(..))) => {
+                                report("unnecessary allocation, the sigil can be \
+                                        removed");
+                            }
+                            (BoxAllocation,
+                             Some(ty::AutoPtr(_, ast::MutImmutable))) => {
+                                report("unnecessary allocation, use & instead");
+                            }
+                            (BoxAllocation,
+                             Some(ty::AutoPtr(_, ast::MutMutable))) => {
+                                report("unnecessary allocation, use &mut \
+                                        instead");
+                            }
+                            _ => ()
+                        }
+                    }
+                    _ => {}
+                }
+            }
+            _ => ()
+        }
+    }
+}
+
+pub struct MissingDoc {
+    /// Set of nodes exported from this module.
+    exported_items: Option<ExportedItems>,
+
+    /// Stack of IDs of struct definitions.
+    struct_def_stack: Vec<ast::NodeId>,
+
+    /// Stack of whether #[doc(hidden)] is set
+    /// at each level which has lint attributes.
+    doc_hidden_stack: Vec<bool>,
+}
+
+impl Default for MissingDoc {
+    fn default() -> MissingDoc {
+        MissingDoc {
+            exported_items: None,
+            struct_def_stack: vec!(),
+            doc_hidden_stack: vec!(false),
+        }
+    }
+}
+
+impl MissingDoc {
+    fn doc_hidden(&self) -> bool {
+        *self.doc_hidden_stack.last().expect("empty doc_hidden_stack")
+    }
+
+    fn check_missing_doc_attrs(&self,
+                               cx: &Context,
+                               id: Option<ast::NodeId>,
+                               attrs: &[ast::Attribute],
+                               sp: Span,
+                               desc: &'static str) {
+        // If we're building a test harness, then warning about
+        // documentation is probably not really relevant right now.
+        if cx.tcx.sess.opts.test { return }
+
+        // `#[doc(hidden)]` disables missing_doc check.
+        if self.doc_hidden() { return }
+
+        // Only check publicly-visible items, using the result from the privacy pass.
+        // It's an option so the crate root can also use this function (it doesn't
+        // have a NodeId).
+        let exported = self.exported_items.as_ref().expect("exported_items not set");
+        match id {
+            Some(ref id) if !exported.contains(id) => return,
+            _ => ()
         }
 
-        _ => ()
-    }
-}
-
-pub fn check_missing_doc_attrs(cx: &Context,
-                           id: Option<ast::NodeId>,
-                           attrs: &[ast::Attribute],
-                           sp: Span,
-                           desc: &'static str) {
-    // If we're building a test harness, then warning about
-    // documentation is probably not really relevant right now.
-    if cx.tcx.sess.opts.test { return }
-
-    // `#[doc(hidden)]` disables missing_doc check.
-    if cx.is_doc_hidden { return }
-
-    // Only check publicly-visible items, using the result from the privacy pass. It's an option so
-    // the crate root can also use this function (it doesn't have a NodeId).
-    match id {
-        Some(ref id) if !cx.exported_items.contains(id) => return,
-        _ => ()
-    }
-
-    let has_doc = attrs.iter().any(|a| {
-        match a.node.value.node {
-            ast::MetaNameValue(ref name, _) if name.equiv(&("doc")) => true,
-            _ => false
+        let has_doc = attrs.iter().any(|a| {
+            match a.node.value.node {
+                ast::MetaNameValue(ref name, _) if name.equiv(&("doc")) => true,
+                _ => false
+            }
+        });
+        if !has_doc {
+            cx.span_lint(lint::MissingDoc,
+                         sp,
+                         format!("missing documentation for {}",
+                                 desc).as_slice());
         }
-    });
-    if !has_doc {
-        cx.span_lint(lint::MissingDoc,
-                     sp,
-                     format!("missing documentation for {}",
-                             desc).as_slice());
     }
 }
 
-pub fn check_missing_doc_item(cx: &Context, it: &ast::Item) {
-    let desc = match it.node {
-        ast::ItemFn(..) => "a function",
-        ast::ItemMod(..) => "a module",
-        ast::ItemEnum(..) => "an enum",
-        ast::ItemStruct(..) => "a struct",
-        ast::ItemTrait(..) => "a trait",
-        _ => return
-    };
-    check_missing_doc_attrs(cx,
-                            Some(it.id),
-                            it.attrs.as_slice(),
-                            it.span,
-                            desc);
-}
-
-pub fn check_missing_doc_method(cx: &Context, m: &ast::Method) {
-    // If the method is an impl for a trait, don't doc.
-    if lint::method_context(cx, m) == lint::TraitImpl { return; }
-
-    // Otherwise, doc according to privacy. This will also check
-    // doc for default methods defined on traits.
-    check_missing_doc_attrs(cx,
-                            Some(m.id),
-                            m.attrs.as_slice(),
-                            m.span,
-                            "a method");
-}
-
-pub fn check_missing_doc_ty_method(cx: &Context, tm: &ast::TypeMethod) {
-    check_missing_doc_attrs(cx,
-                            Some(tm.id),
-                            tm.attrs.as_slice(),
-                            tm.span,
-                            "a type method");
-}
-
-pub fn check_missing_doc_struct_field(cx: &Context, sf: &ast::StructField) {
-    match sf.node.kind {
-        ast::NamedField(_, vis) if vis == ast::Public =>
-            check_missing_doc_attrs(cx,
-                                    Some(cx.cur_struct_def_id),
-                                    sf.node.attrs.as_slice(),
-                                    sf.span,
-                                    "a struct field"),
-        _ => {}
+impl LintPass for MissingDoc {
+    fn enter_lint_attrs(&mut self, _: &Context, attrs: &[ast::Attribute]) {
+        let doc_hidden = self.doc_hidden() || attrs.iter().any(|attr| {
+            attr.check_name("doc") && match attr.meta_item_list() {
+                None => false,
+                Some(l) => attr::contains_name(l.as_slice(), "hidden"),
+            }
+        });
+        self.doc_hidden_stack.push(doc_hidden);
     }
-}
 
-pub fn check_missing_doc_variant(cx: &Context, v: &ast::Variant) {
-    check_missing_doc_attrs(cx,
-                            Some(v.node.id),
-                            v.node.attrs.as_slice(),
-                            v.span,
-                            "a variant");
+    fn exit_lint_attrs(&mut self, _: &Context, _: &[ast::Attribute]) {
+        self.doc_hidden_stack.pop().expect("empty doc_hidden_stack");
+    }
+
+    fn check_struct_def(&mut self, _: &Context,
+        _: &ast::StructDef, _: ast::Ident, _: &ast::Generics, id: ast::NodeId) {
+        self.struct_def_stack.push(id);
+    }
+
+    fn check_struct_def_post(&mut self, _: &Context,
+        _: &ast::StructDef, _: ast::Ident, _: &ast::Generics, id: ast::NodeId) {
+        let popped = self.struct_def_stack.pop().expect("empty struct_def_stack");
+        assert!(popped == id);
+    }
+
+    fn check_crate(&mut self, cx: &Context, exported: &ExportedItems, krate: &ast::Crate) {
+        // FIXME: clone to avoid lifetime trickiness
+        self.exported_items = Some(exported.clone());
+
+        self.check_missing_doc_attrs(cx, None, krate.attrs.as_slice(),
+            krate.span, "crate");
+    }
+
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        let desc = match it.node {
+            ast::ItemFn(..) => "a function",
+            ast::ItemMod(..) => "a module",
+            ast::ItemEnum(..) => "an enum",
+            ast::ItemStruct(..) => "a struct",
+            ast::ItemTrait(..) => "a trait",
+            _ => return
+        };
+        self.check_missing_doc_attrs(cx, Some(it.id), it.attrs.as_slice(),
+            it.span, desc);
+    }
+
+    fn check_fn(&mut self, cx: &Context,
+            fk: &visit::FnKind, _: &ast::FnDecl, _: &ast::Block, _: Span, _: ast::NodeId) {
+        match *fk {
+            visit::FkMethod(_, _, m) => {
+                // If the method is an impl for a trait, don't doc.
+                if method_context(cx, m) == TraitImpl { return; }
+
+                // Otherwise, doc according to privacy. This will also check
+                // doc for default methods defined on traits.
+                self.check_missing_doc_attrs(cx, Some(m.id), m.attrs.as_slice(),
+                    m.span, "a method");
+            }
+            _ => {}
+        }
+    }
+
+    fn check_ty_method(&mut self, cx: &Context, tm: &ast::TypeMethod) {
+        self.check_missing_doc_attrs(cx, Some(tm.id), tm.attrs.as_slice(),
+            tm.span, "a type method");
+    }
+
+    fn check_struct_field(&mut self, cx: &Context, sf: &ast::StructField) {
+        match sf.node.kind {
+            ast::NamedField(_, vis) if vis == ast::Public => {
+                let cur_struct_def = *self.struct_def_stack.last().expect("empty struct_def_stack");
+                self.check_missing_doc_attrs(cx, Some(cur_struct_def),
+                    sf.node.attrs.as_slice(), sf.span, "a struct field")
+            }
+            _ => {}
+        }
+    }
+
+    fn check_variant(&mut self, cx: &Context, v: &ast::Variant, _: &ast::Generics) {
+        self.check_missing_doc_attrs(cx, Some(v.node.id), v.node.attrs.as_slice(),
+            v.span, "a variant");
+    }
 }
 
 /// Checks for use of items with #[deprecated], #[experimental] and
 /// #[unstable] (or none of them) attributes.
-pub fn check_stability(cx: &Context, e: &ast::Expr) {
-    let id = match e.node {
-        ast::ExprPath(..) | ast::ExprStruct(..) => {
-            match cx.tcx.def_map.borrow().find(&e.id) {
-                Some(&def) => def.def_id(),
-                None => return
-            }
-        }
-        ast::ExprMethodCall(..) => {
-            let method_call = typeck::MethodCall::expr(e.id);
-            match cx.tcx.method_map.borrow().find(&method_call) {
-                Some(method) => {
-                    match method.origin {
-                        typeck::MethodStatic(def_id) => {
-                            // If this implements a trait method, get def_id
-                            // of the method inside trait definition.
-                            // Otherwise, use the current def_id (which refers
-                            // to the method inside impl).
-                            ty::trait_method_of_method(
-                                cx.tcx, def_id).unwrap_or(def_id)
-                        }
-                        typeck::MethodParam(typeck::MethodParam {
-                            trait_id: trait_id,
-                            method_num: index,
-                            ..
-                        })
-                        | typeck::MethodObject(typeck::MethodObject {
-                            trait_id: trait_id,
-                            method_num: index,
-                            ..
-                        }) => ty::trait_method(cx.tcx, trait_id, index).def_id
-                    }
+#[deriving(Default)]
+pub struct Stability;
+
+impl LintPass for Stability {
+    fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
+        let id = match e.node {
+            ast::ExprPath(..) | ast::ExprStruct(..) => {
+                match cx.tcx.def_map.borrow().find(&e.id) {
+                    Some(&def) => def.def_id(),
+                    None => return
                 }
+            }
+            ast::ExprMethodCall(..) => {
+                let method_call = typeck::MethodCall::expr(e.id);
+                match cx.tcx.method_map.borrow().find(&method_call) {
+                    Some(method) => {
+                        match method.origin {
+                            typeck::MethodStatic(def_id) => {
+                                // If this implements a trait method, get def_id
+                                // of the method inside trait definition.
+                                // Otherwise, use the current def_id (which refers
+                                // to the method inside impl).
+                                ty::trait_method_of_method(
+                                    cx.tcx, def_id).unwrap_or(def_id)
+                            }
+                            typeck::MethodParam(typeck::MethodParam {
+                                trait_id: trait_id,
+                                method_num: index,
+                                ..
+                            })
+                            | typeck::MethodObject(typeck::MethodObject {
+                                trait_id: trait_id,
+                                method_num: index,
+                                ..
+                            }) => ty::trait_method(cx.tcx, trait_id, index).def_id
+                        }
+                    }
+                    None => return
+                }
+            }
+            _ => return
+        };
+
+        let stability = if ast_util::is_local(id) {
+            // this crate
+            let s = cx.tcx.map.with_attrs(id.node, |attrs| {
+                attrs.map(|a| attr::find_stability(a.as_slice()))
+            });
+            match s {
+                Some(s) => s,
+
+                // no possibility of having attributes
+                // (e.g. it's a local variable), so just
+                // ignore it.
                 None => return
             }
-        }
-        _ => return
-    };
+        } else {
+            // cross-crate
 
-    let stability = if ast_util::is_local(id) {
-        // this crate
-        let s = cx.tcx.map.with_attrs(id.node, |attrs| {
-            attrs.map(|a| attr::find_stability(a.as_slice()))
-        });
-        match s {
-            Some(s) => s,
+            let mut s = None;
+            // run through all the attributes and take the first
+            // stability one.
+            csearch::get_item_attrs(&cx.tcx.sess.cstore, id, |attrs| {
+                if s.is_none() {
+                    s = attr::find_stability(attrs.as_slice())
+                }
+            });
+            s
+        };
 
-            // no possibility of having attributes
-            // (e.g. it's a local variable), so just
-            // ignore it.
-            None => return
-        }
-    } else {
-        // cross-crate
+        let (lint, label) = match stability {
+            // no stability attributes == Unstable
+            None => (lint::Unstable, "unmarked"),
+            Some(attr::Stability { level: attr::Unstable, .. }) =>
+                    (lint::Unstable, "unstable"),
+            Some(attr::Stability { level: attr::Experimental, .. }) =>
+                    (lint::Experimental, "experimental"),
+            Some(attr::Stability { level: attr::Deprecated, .. }) =>
+                    (lint::Deprecated, "deprecated"),
+            _ => return
+        };
 
-        let mut s = None;
-        // run through all the attributes and take the first
-        // stability one.
-        csearch::get_item_attrs(&cx.tcx.sess.cstore, id, |attrs| {
-            if s.is_none() {
-                s = attr::find_stability(attrs.as_slice())
+        let msg = match stability {
+            Some(attr::Stability { text: Some(ref s), .. }) => {
+                format!("use of {} item: {}", label, *s)
             }
-        });
-        s
-    };
+            _ => format!("use of {} item", label)
+        };
 
-    let (lint, label) = match stability {
-        // no stability attributes == Unstable
-        None => (lint::Unstable, "unmarked"),
-        Some(attr::Stability { level: attr::Unstable, .. }) =>
-                (lint::Unstable, "unstable"),
-        Some(attr::Stability { level: attr::Experimental, .. }) =>
-                (lint::Experimental, "experimental"),
-        Some(attr::Stability { level: attr::Deprecated, .. }) =>
-                (lint::Deprecated, "deprecated"),
-        _ => return
-    };
-
-    let msg = match stability {
-        Some(attr::Stability { text: Some(ref s), .. }) => {
-            format!("use of {} item: {}", label, *s)
-        }
-        _ => format!("use of {} item", label)
-    };
-
-    cx.span_lint(lint, e.span, msg.as_slice());
-}
-
-pub fn check_enum_variant_sizes(cx: &mut Context, it: &ast::Item) {
-    match it.node {
-        ast::ItemEnum(..) => {
-            match cx.cur.find(&(lint::VariantSizeDifference as uint)) {
-                Some(&(lvl, src)) if lvl != lint::Allow => {
-                    cx.node_levels.insert((it.id, lint::VariantSizeDifference), (lvl, src));
-                },
-                _ => { }
-            }
-        },
-        _ => { }
+        cx.span_lint(lint, e.span, msg.as_slice());
     }
 }
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index bd3b1bc7d00..04d0e60cbf9 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -28,36 +28,94 @@
 //! upon.  As the ast is traversed, this keeps track of the current lint level
 //! for all lint attributes.
 //!
-//! To add a new lint warning, all you need to do is to either invoke `add_lint`
-//! on the session at the appropriate time, or write a few linting functions and
-//! modify the Context visitor appropriately. If you're adding lints from the
-//! Context itself, span_lint should be used instead of add_lint.
+//! Most of the lints built into `rustc` are structs implementing `LintPass`,
+//! and are defined within `builtin.rs`. To add a new lint you can define such
+//! a struct and add it to the `builtin_lints!` macro invocation in this file.
+//! `LintPass` itself is not a subtrait of `Default`, but the `builtin_lints!`
+//! macro requires `Default` (usually via `deriving`).
+//!
+//! Some lints are defined elsewhere in the compiler and work by calling
+//! `add_lint()` on the overall `Session` object.
+//!
+//! If you're adding lints to the `Context` infrastructure itself, defined in
+//! this file, use `span_lint` instead of `add_lint`.
 
 #![allow(non_camel_case_types)]
 
 use driver::session;
 use middle::dead::DEAD_CODE_LINT_STR;
-use middle::privacy;
+use middle::privacy::ExportedItems;
 use middle::ty;
 use middle::typeck::astconv::AstConv;
 use middle::typeck::infer;
-use util::nodemap::NodeSet;
 
 use std::collections::HashMap;
 use std::rc::Rc;
 use std::gc::Gc;
 use std::to_str::ToStr;
+use std::cell::RefCell;
+use std::default::Default;
 use std::collections::SmallIntMap;
 use syntax::ast_util::IdVisitingOperation;
 use syntax::attr::AttrMetaMethods;
-use syntax::attr;
 use syntax::codemap::Span;
 use syntax::parse::token::InternedString;
-use syntax::visit::Visitor;
+use syntax::visit::{Visitor, FnKind};
 use syntax::{ast, ast_util, visit};
 
 mod builtin;
 
+/// Trait for types providing lint checks. Each method checks a single syntax
+/// node, and should not invoke methods recursively (unlike `Visitor`).  Each
+/// method has a default do-nothing implementation. The trait also contains a
+/// few lint-specific methods with no equivalent in `Visitor`.
+//
+// FIXME: eliminate the duplication with `Visitor`
+trait LintPass {
+    fn check_crate(&mut self, _: &Context, _: &ExportedItems, _: &ast::Crate) { }
+    fn check_ident(&mut self, _: &Context, _: Span, _: ast::Ident) { }
+    fn check_mod(&mut self, _: &Context, _: &ast::Mod, _: Span, _: ast::NodeId) { }
+    fn check_view_item(&mut self, _: &Context, _: &ast::ViewItem) { }
+    fn check_foreign_item(&mut self, _: &Context, _: &ast::ForeignItem) { }
+    fn check_item(&mut self, _: &Context, _: &ast::Item) { }
+    fn check_local(&mut self, _: &Context, _: &ast::Local) { }
+    fn check_block(&mut self, _: &Context, _: &ast::Block) { }
+    fn check_stmt(&mut self, _: &Context, _: &ast::Stmt) { }
+    fn check_arm(&mut self, _: &Context, _: &ast::Arm) { }
+    fn check_pat(&mut self, _: &Context, _: &ast::Pat) { }
+    fn check_decl(&mut self, _: &Context, _: &ast::Decl) { }
+    fn check_expr(&mut self, _: &Context, _: &ast::Expr) { }
+    fn check_expr_post(&mut self, _: &Context, _: &ast::Expr) { }
+    fn check_ty(&mut self, _: &Context, _: &ast::Ty) { }
+    fn check_generics(&mut self, _: &Context, _: &ast::Generics) { }
+    fn check_fn(&mut self, _: &Context,
+        _: &FnKind, _: &ast::FnDecl, _: &ast::Block, _: Span, _: ast::NodeId) { }
+    fn check_ty_method(&mut self, _: &Context, _: &ast::TypeMethod) { }
+    fn check_trait_method(&mut self, _: &Context, _: &ast::TraitMethod) { }
+    fn check_struct_def(&mut self, _: &Context,
+        _: &ast::StructDef, _: ast::Ident, _: &ast::Generics, _: ast::NodeId) { }
+    fn check_struct_def_post(&mut self, _: &Context,
+        _: &ast::StructDef, _: ast::Ident, _: &ast::Generics, _: ast::NodeId) { }
+    fn check_struct_field(&mut self, _: &Context, _: &ast::StructField) { }
+    fn check_variant(&mut self, _: &Context, _: &ast::Variant, _: &ast::Generics) { }
+    fn check_opt_lifetime_ref(&mut self, _: &Context, _: Span, _: &Option<ast::Lifetime>) { }
+    fn check_lifetime_ref(&mut self, _: &Context, _: &ast::Lifetime) { }
+    fn check_lifetime_decl(&mut self, _: &Context, _: &ast::Lifetime) { }
+    fn check_explicit_self(&mut self, _: &Context, _: &ast::ExplicitSelf) { }
+    fn check_mac(&mut self, _: &Context, _: &ast::Mac) { }
+    fn check_path(&mut self, _: &Context, _: &ast::Path, _: ast::NodeId) { }
+    fn check_attribute(&mut self, _: &Context, _: &ast::Attribute) { }
+
+    /// Called when entering a syntax node that can have lint attributes such
+    /// as `#[allow(...)]`. Called with *all* the attributes of that node.
+    fn enter_lint_attrs(&mut self, _: &Context, _: &[ast::Attribute]) { }
+
+    /// Counterpart to `enter_lint_attrs`.
+    fn exit_lint_attrs(&mut self, _: &Context, _: &[ast::Attribute]) { }
+}
+
+type LintPassObject = Box<LintPass + 'static>;
+
 #[deriving(Clone, Show, PartialEq, PartialOrd, Eq, Ord, Hash)]
 pub enum LintId {
     CTypes,
@@ -438,30 +496,27 @@ struct Context<'a> {
     cur: SmallIntMap<(Level, LintSource)>,
     /// Context we're checking in (used to access fields like sess)
     tcx: &'a ty::ctxt,
-    /// Items exported by the crate; used by the missing_doc lint.
-    exported_items: &'a privacy::ExportedItems,
-    /// The id of the current `ast::StructDef` being walked.
-    cur_struct_def_id: ast::NodeId,
-    /// Whether some ancestor of the current node was marked
-    /// #[doc(hidden)].
-    is_doc_hidden: bool,
 
     /// When recursing into an attributed node of the ast which modifies lint
     /// levels, this stack keeps track of the previous lint levels of whatever
     /// was modified.
-    lint_stack: Vec<(LintId, Level, LintSource)>,
-
-    /// Id of the last visited negated expression
-    negated_expr_id: ast::NodeId,
-
-    /// Ids of structs/enums which have been checked for raw_pointer_deriving
-    checked_raw_pointers: NodeSet,
+    level_stack: Vec<(LintId, Level, LintSource)>,
 
     /// Level of lints for certain NodeIds, stored here because the body of
     /// the lint needs to run in trans.
-    node_levels: HashMap<(ast::NodeId, LintId), (Level, LintSource)>,
+    node_levels: RefCell<HashMap<(ast::NodeId, LintId), (Level, LintSource)>>,
+
+    /// Trait objects for each lint.
+    lints: Vec<RefCell<LintPassObject>>,
 }
 
+/// Convenience macro for calling a `LintPass` method on every lint in the context.
+macro_rules! run_lints ( ($cx:expr, $f:ident, $($args:expr),*) => (
+    for tl in $cx.lints.iter() {
+        tl.borrow_mut().$f($cx, $($args),*);
+    }
+))
+
 pub fn emit_lint(level: Level, src: LintSource, msg: &str, span: Span,
                  lint_str: &str, tcx: &ty::ctxt) {
     if level == Allow { return }
@@ -581,7 +636,7 @@ impl<'a> Context<'a> {
                                 lintname).as_slice());
                     } else if now != level {
                         let src = self.get_source(lint);
-                        self.lint_stack.push((lint, now, src));
+                        self.level_stack.push((lint, now, src));
                         pushed += 1;
                         self.set_level(lint, level, Node(meta.span));
                     }
@@ -590,26 +645,13 @@ impl<'a> Context<'a> {
             true
         });
 
-        let old_is_doc_hidden = self.is_doc_hidden;
-        self.is_doc_hidden =
-            self.is_doc_hidden ||
-            attrs.iter()
-                 .any(|attr| {
-                     attr.name().equiv(&("doc")) &&
-                     match attr.meta_item_list() {
-                         None => false,
-                         Some(l) => {
-                             attr::contains_name(l.as_slice(), "hidden")
-                         }
-                     }
-                 });
-
+        run_lints!(self, enter_lint_attrs, attrs);
         f(self);
+        run_lints!(self, exit_lint_attrs, attrs);
 
         // rollback
-        self.is_doc_hidden = old_is_doc_hidden;
         for _ in range(0, pushed) {
-            let (lint, lvl, src) = self.lint_stack.pop().unwrap();
+            let (lint, lvl, src) = self.level_stack.pop().unwrap();
             self.set_level(lint, lvl, src);
         }
     }
@@ -622,6 +664,10 @@ impl<'a> Context<'a> {
         };
         f(&mut v);
     }
+
+    fn insert_node_level(&self, id: ast::NodeId, lint: LintId, lvl: Level, src: LintSource) {
+        self.node_levels.borrow_mut().insert((id, lint), (lvl, src));
+    }
 }
 
 /// Check that every lint from the list of attributes satisfies `f`.
@@ -680,35 +726,6 @@ pub fn contains_lint(attrs: &[ast::Attribute],
     false
 }
 
-#[deriving(PartialEq)]
-enum MethodContext {
-    TraitDefaultImpl,
-    TraitImpl,
-    PlainImpl
-}
-
-fn method_context(cx: &Context, m: &ast::Method) -> MethodContext {
-    let did = ast::DefId {
-        krate: ast::LOCAL_CRATE,
-        node: m.id
-    };
-
-    match cx.tcx.methods.borrow().find_copy(&did) {
-        None => cx.tcx.sess.span_bug(m.span, "missing method descriptor?!"),
-        Some(md) => {
-            match md.container {
-                ty::TraitContainer(..) => TraitDefaultImpl,
-                ty::ImplContainer(cid) => {
-                    match ty::impl_trait_ref(cx.tcx, cid) {
-                        Some(..) => TraitImpl,
-                        None => PlainImpl
-                    }
-                }
-            }
-        }
-    }
-}
-
 impl<'a> AstConv for Context<'a>{
     fn tcx<'a>(&'a self) -> &'a ty::ctxt { self.tcx }
 
@@ -728,175 +745,170 @@ impl<'a> AstConv for Context<'a>{
 impl<'a> Visitor<()> for Context<'a> {
     fn visit_item(&mut self, it: &ast::Item, _: ()) {
         self.with_lint_attrs(it.attrs.as_slice(), |cx| {
-            builtin::check_enum_variant_sizes(cx, it);
-            builtin::check_item_ctypes(cx, it);
-            builtin::check_item_non_camel_case_types(cx, it);
-            builtin::check_item_non_uppercase_statics(cx, it);
-            builtin::check_heap_item(cx, it);
-            builtin::check_missing_doc_item(cx, it);
-            builtin::check_raw_ptr_deriving(cx, it);
-
+            run_lints!(cx, check_item, it);
             cx.visit_ids(|v| v.visit_item(it, ()));
-
             visit::walk_item(cx, it, ());
         })
     }
 
     fn visit_foreign_item(&mut self, it: &ast::ForeignItem, _: ()) {
         self.with_lint_attrs(it.attrs.as_slice(), |cx| {
+            run_lints!(cx, check_foreign_item, it);
             visit::walk_foreign_item(cx, it, ());
         })
     }
 
     fn visit_view_item(&mut self, i: &ast::ViewItem, _: ()) {
         self.with_lint_attrs(i.attrs.as_slice(), |cx| {
+            run_lints!(cx, check_view_item, i);
             cx.visit_ids(|v| v.visit_view_item(i, ()));
-
             visit::walk_view_item(cx, i, ());
         })
     }
 
     fn visit_pat(&mut self, p: &ast::Pat, _: ()) {
-        builtin::check_pat_non_uppercase_statics(self, p);
-        builtin::check_pat_uppercase_variable(self, p);
-
+        run_lints!(self, check_pat, p);
         visit::walk_pat(self, p, ());
     }
 
     fn visit_expr(&mut self, e: &ast::Expr, _: ()) {
-        match e.node {
-            ast::ExprUnary(ast::UnNeg, expr) => {
-                // propagate negation, if the negation itself isn't negated
-                if self.negated_expr_id != e.id {
-                    self.negated_expr_id = expr.id;
-                }
-            },
-            ast::ExprParen(expr) => if self.negated_expr_id == e.id {
-                self.negated_expr_id = expr.id
-            },
-            ast::ExprMatch(_, ref arms) => {
-                for a in arms.iter() {
-                    builtin::check_unused_mut_pat(self, a.pats.as_slice());
-                }
-            },
-            _ => ()
-        };
-
-        builtin::check_while_true_expr(self, e);
-        builtin::check_stability(self, e);
-        builtin::check_unnecessary_parens_expr(self, e);
-        builtin::check_unused_unsafe(self, e);
-        builtin::check_unsafe_block(self, e);
-        builtin::check_unnecessary_allocation(self, e);
-        builtin::check_heap_expr(self, e);
-
-        builtin::check_type_limits(self, e);
-        builtin::check_unused_casts(self, e);
-
+        run_lints!(self, check_expr, e);
         visit::walk_expr(self, e, ());
     }
 
     fn visit_stmt(&mut self, s: &ast::Stmt, _: ()) {
-        builtin::check_path_statement(self, s);
-        builtin::check_unused_result(self, s);
-        builtin::check_unnecessary_parens_stmt(self, s);
-
-        match s.node {
-            ast::StmtDecl(d, _) => {
-                match d.node {
-                    ast::DeclLocal(l) => {
-                        builtin::check_unused_mut_pat(self, &[l.pat]);
-                    },
-                    _ => {}
-                }
-            },
-            _ => {}
-        }
-
+        run_lints!(self, check_stmt, s);
         visit::walk_stmt(self, s, ());
     }
 
-    fn visit_fn(&mut self, fk: &visit::FnKind, decl: &ast::FnDecl,
+    fn visit_fn(&mut self, fk: &FnKind, decl: &ast::FnDecl,
                 body: &ast::Block, span: Span, id: ast::NodeId, _: ()) {
-        let recurse = |this: &mut Context| {
-            visit::walk_fn(this, fk, decl, body, span, ());
-        };
-
-        for a in decl.inputs.iter(){
-            builtin::check_unused_mut_pat(self, &[a.pat]);
-        }
-
         match *fk {
-            visit::FkMethod(ident, _, m) => {
+            visit::FkMethod(_, _, m) => {
                 self.with_lint_attrs(m.attrs.as_slice(), |cx| {
-                    builtin::check_missing_doc_method(cx, m);
-
-                    match method_context(cx, m) {
-                        PlainImpl
-                            => builtin::check_snake_case(cx, "method", ident, span),
-                        TraitDefaultImpl
-                            => builtin::check_snake_case(cx, "trait method", ident, span),
-                        _ => (),
-                    }
-
+                    run_lints!(cx, check_fn, fk, decl, body, span, id);
                     cx.visit_ids(|v| {
                         v.visit_fn(fk, decl, body, span, id, ());
                     });
-                    recurse(cx);
+                    visit::walk_fn(cx, fk, decl, body, span, ());
                 })
             },
-            visit::FkItemFn(ident, _, _, _) => {
-                builtin::check_snake_case(self, "function", ident, span);
-                recurse(self);
+            _ => {
+                run_lints!(self, check_fn, fk, decl, body, span, id);
+                visit::walk_fn(self, fk, decl, body, span, ());
             }
-            _ => recurse(self),
         }
     }
 
     fn visit_ty_method(&mut self, t: &ast::TypeMethod, _: ()) {
         self.with_lint_attrs(t.attrs.as_slice(), |cx| {
-            builtin::check_missing_doc_ty_method(cx, t);
-            builtin::check_snake_case(cx, "trait method", t.ident, t.span);
-
+            run_lints!(cx, check_ty_method, t);
             visit::walk_ty_method(cx, t, ());
         })
     }
 
     fn visit_struct_def(&mut self,
                         s: &ast::StructDef,
-                        _: ast::Ident,
-                        _: &ast::Generics,
+                        ident: ast::Ident,
+                        g: &ast::Generics,
                         id: ast::NodeId,
                         _: ()) {
-        builtin::check_struct_uppercase_variable(self, s);
-
-        let old_id = self.cur_struct_def_id;
-        self.cur_struct_def_id = id;
+        run_lints!(self, check_struct_def, s, ident, g, id);
         visit::walk_struct_def(self, s, ());
-        self.cur_struct_def_id = old_id;
+        run_lints!(self, check_struct_def_post, s, ident, g, id);
     }
 
     fn visit_struct_field(&mut self, s: &ast::StructField, _: ()) {
         self.with_lint_attrs(s.node.attrs.as_slice(), |cx| {
-            builtin::check_missing_doc_struct_field(cx, s);
-
+            run_lints!(cx, check_struct_field, s);
             visit::walk_struct_field(cx, s, ());
         })
     }
 
     fn visit_variant(&mut self, v: &ast::Variant, g: &ast::Generics, _: ()) {
         self.with_lint_attrs(v.node.attrs.as_slice(), |cx| {
-            builtin::check_missing_doc_variant(cx, v);
-
+            run_lints!(cx, check_variant, v, g);
             visit::walk_variant(cx, v, g, ());
         })
     }
 
     // FIXME(#10894) should continue recursing
-    fn visit_ty(&mut self, _t: &ast::Ty, _: ()) {}
+    fn visit_ty(&mut self, t: &ast::Ty, _: ()) {
+        run_lints!(self, check_ty, t);
+    }
+
+    fn visit_ident(&mut self, sp: Span, id: ast::Ident, _: ()) {
+        run_lints!(self, check_ident, sp, id);
+    }
+
+    fn visit_mod(&mut self, m: &ast::Mod, s: Span, n: ast::NodeId, _: ()) {
+        run_lints!(self, check_mod, m, s, n);
+        visit::walk_mod(self, m, ());
+    }
+
+    fn visit_local(&mut self, l: &ast::Local, _: ()) {
+        run_lints!(self, check_local, l);
+        visit::walk_local(self, l, ());
+    }
+
+    fn visit_block(&mut self, b: &ast::Block, _: ()) {
+        run_lints!(self, check_block, b);
+        visit::walk_block(self, b, ());
+    }
+
+    fn visit_arm(&mut self, a: &ast::Arm, _: ()) {
+        run_lints!(self, check_arm, a);
+        visit::walk_arm(self, a, ());
+    }
+
+    fn visit_decl(&mut self, d: &ast::Decl, _: ()) {
+        run_lints!(self, check_decl, d);
+        visit::walk_decl(self, d, ());
+    }
+
+    fn visit_expr_post(&mut self, e: &ast::Expr, _: ()) {
+        run_lints!(self, check_expr_post, e);
+    }
+
+    fn visit_generics(&mut self, g: &ast::Generics, _: ()) {
+        run_lints!(self, check_generics, g);
+        visit::walk_generics(self, g, ());
+    }
+
+    fn visit_trait_method(&mut self, m: &ast::TraitMethod, _: ()) {
+        run_lints!(self, check_trait_method, m);
+        visit::walk_trait_method(self, m, ());
+    }
+
+    fn visit_opt_lifetime_ref(&mut self, sp: Span, lt: &Option<ast::Lifetime>, _: ()) {
+        run_lints!(self, check_opt_lifetime_ref, sp, lt);
+    }
+
+    fn visit_lifetime_ref(&mut self, lt: &ast::Lifetime, _: ()) {
+        run_lints!(self, check_lifetime_ref, lt);
+    }
+
+    fn visit_lifetime_decl(&mut self, lt: &ast::Lifetime, _: ()) {
+        run_lints!(self, check_lifetime_decl, lt);
+    }
+
+    fn visit_explicit_self(&mut self, es: &ast::ExplicitSelf, _: ()) {
+        run_lints!(self, check_explicit_self, es);
+        visit::walk_explicit_self(self, es, ());
+    }
+
+    fn visit_mac(&mut self, mac: &ast::Mac, _: ()) {
+        run_lints!(self, check_mac, mac);
+        visit::walk_mac(self, mac, ());
+    }
+
+    fn visit_path(&mut self, p: &ast::Path, id: ast::NodeId, _: ()) {
+        run_lints!(self, check_path, p, id);
+        visit::walk_path(self, p, ());
+    }
 
     fn visit_attribute(&mut self, attr: &ast::Attribute, _: ()) {
-        builtin::check_unused_attribute(self, attr);
+        run_lints!(self, check_attribute, attr);
     }
 }
 
@@ -914,19 +926,33 @@ impl<'a> IdVisitingOperation for Context<'a> {
 }
 
 pub fn check_crate(tcx: &ty::ctxt,
-                   exported_items: &privacy::ExportedItems,
+                   exported_items: &ExportedItems,
                    krate: &ast::Crate) {
+    macro_rules! builtin_lints (( $($name:ident),*, ) => (
+        vec!($(
+            {
+                let obj: builtin::$name = Default::default();
+                RefCell::new(box obj as LintPassObject)
+            }
+        ),*)
+    ))
+
+    let builtin_lints = builtin_lints!(
+        GatherNodeLevels, WhileTrue, UnusedCasts, TypeLimits, CTypes,
+        HeapMemory, RawPointerDeriving, UnusedAttribute,
+        PathStatement, UnusedMustUse, DeprecatedOwnedVector,
+        NonCamelCaseTypes, NonSnakeCaseFunctions, NonUppercaseStatics,
+        UppercaseVariables, UnnecessaryParens, UnusedUnsafe, UnsafeBlock,
+        UnusedMut, UnnecessaryAllocation, MissingDoc, Stability,
+    );
+
     let mut cx = Context {
         dict: get_lint_dict(),
         cur: SmallIntMap::new(),
         tcx: tcx,
-        exported_items: exported_items,
-        cur_struct_def_id: -1,
-        is_doc_hidden: false,
-        lint_stack: Vec::new(),
-        negated_expr_id: -1,
-        checked_raw_pointers: NodeSet::new(),
-        node_levels: HashMap::new(),
+        level_stack: Vec::new(),
+        node_levels: RefCell::new(HashMap::new()),
+        lints: builtin_lints,
     };
 
     // Install default lint levels, followed by the command line levels, and
@@ -946,13 +972,9 @@ pub fn check_crate(tcx: &ty::ctxt,
             visit::walk_crate(v, krate, ());
         });
 
-        // since the root module isn't visited as an item (because it isn't an item), warn for it
-        // here.
-        builtin::check_missing_doc_attrs(cx,
-                                         None,
-                                         krate.attrs.as_slice(),
-                                         krate.span,
-                                         "crate");
+        // since the root module isn't visited as an item (because it isn't an
+        // item), warn for it here.
+        run_lints!(cx, check_crate, exported_items, krate);
 
         visit::walk_crate(cx, krate, ());
     });
@@ -967,5 +989,5 @@ pub fn check_crate(tcx: &ty::ctxt,
     }
 
     tcx.sess.abort_if_errors();
-    *tcx.node_lint_levels.borrow_mut() = cx.node_levels;
+    *tcx.node_lint_levels.borrow_mut() = cx.node_levels.unwrap();
 }