Replace enum LintId with an extensible alternative

16 files changed, 744 insertions, 766 deletions

diff --git a/src/librustc/driver/config.rs b/src/librustc/driver/config.rs
index f56e5128712..d815e3d8a86 100644
--- a/src/librustc/driver/config.rs
+++ b/src/librustc/driver/config.rs
@@ -70,7 +70,8 @@ pub struct Options {
     pub gc: bool,
     pub optimize: OptLevel,
     pub debuginfo: DebugInfoLevel,
-    pub lint_opts: Vec<(lint::LintId, lint::Level)> ,
+    pub lint_opts: Vec<(String, lint::Level)>,
+    pub describe_lints: bool,
     pub output_types: Vec<back::link::OutputType> ,
     // This was mutable for rustpkg, which updates search paths based on the
     // parsed code. It remains mutable in case its replacements wants to use
@@ -104,6 +105,7 @@ pub fn basic_options() -> Options {
         optimize: No,
         debuginfo: NoDebugInfo,
         lint_opts: Vec::new(),
+        describe_lints: false,
         output_types: Vec::new(),
         addl_lib_search_paths: RefCell::new(HashSet::new()),
         maybe_sysroot: None,
@@ -585,30 +587,15 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
     let no_trans = matches.opt_present("no-trans");
     let no_analysis = matches.opt_present("no-analysis");
 
-    let lint_levels = [lint::Allow, lint::Warn,
-                       lint::Deny, lint::Forbid];
-    let mut lint_opts = Vec::new();
-    let lint_dict = lint::get_lint_dict();
-    for level in lint_levels.iter() {
-        let level_name = lint::level_to_str(*level);
-
-        let level_short = level_name.slice_chars(0, 1);
-        let level_short = level_short.to_ascii().to_upper().into_str();
-        let flags = matches.opt_strs(level_short.as_slice())
-                           .move_iter()
-                           .collect::<Vec<_>>()
-                           .append(matches.opt_strs(level_name).as_slice());
-        for lint_name in flags.iter() {
-            let lint_name = lint_name.replace("-", "_").into_string();
-            match lint_dict.find_equiv(&lint_name) {
-              None => {
-                early_error(format!("unknown {} flag: {}",
-                                    level_name,
-                                    lint_name).as_slice());
-              }
-              Some(lint) => {
-                lint_opts.push((lint.lint, *level));
-              }
+    let mut lint_opts = vec!();
+    let mut describe_lints = false;
+
+    for &level in [lint::Allow, lint::Warn, lint::Deny, lint::Forbid].iter() {
+        for lint_name in matches.opt_strs(level.as_str()).move_iter() {
+            if lint_name.as_slice() == "help" {
+                describe_lints = true;
+            } else {
+                lint_opts.push((lint_name.replace("-", "_").into_string(), level));
             }
         }
     }
@@ -752,6 +739,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         optimize: opt_level,
         debuginfo: debuginfo,
         lint_opts: lint_opts,
+        describe_lints: describe_lints,
         output_types: output_types,
         addl_lib_search_paths: RefCell::new(addl_lib_search_paths),
         maybe_sysroot: sysroot_opt,
diff --git a/src/librustc/driver/driver.rs b/src/librustc/driver/driver.rs
index fca6db23be6..2aa2746959f 100644
--- a/src/librustc/driver/driver.rs
+++ b/src/librustc/driver/driver.rs
@@ -767,7 +767,7 @@ pub fn collect_crate_types(session: &Session,
                 }
                 Some(ref n) if n.equiv(&("bin")) => Some(config::CrateTypeExecutable),
                 Some(_) => {
-                    session.add_lint(lint::UnknownCrateType,
+                    session.add_lint(lint::builtin::unknown_crate_type,
                                      ast::CRATE_NODE_ID,
                                      a.span,
                                      "invalid `crate_type` \
@@ -775,7 +775,7 @@ pub fn collect_crate_types(session: &Session,
                     None
                 }
                 _ => {
-                    session.add_lint(lint::UnknownCrateType,
+                    session.add_lint(lint::builtin::unknown_crate_type,
                                      ast::CRATE_NODE_ID,
                                      a.span,
                                      "`crate_type` requires a \
diff --git a/src/librustc/driver/mod.rs b/src/librustc/driver/mod.rs
index 71c97f0265f..623698f6c71 100644
--- a/src/librustc/driver/mod.rs
+++ b/src/librustc/driver/mod.rs
@@ -17,7 +17,6 @@ use lint;
 use metadata;
 
 use std::any::AnyRefExt;
-use std::cmp;
 use std::io;
 use std::os;
 use std::str;
@@ -50,6 +49,12 @@ fn run_compiler(args: &[String]) {
         None => return
     };
 
+    let sopts = config::build_session_options(&matches);
+    if sopts.describe_lints {
+        describe_lints();
+        return;
+    }
+
     let (input, input_file_path) = match matches.free.len() {
         0u => early_error("no input filename given"),
         1u => {
@@ -66,7 +71,6 @@ fn run_compiler(args: &[String]) {
         _ => early_error("multiple input filenames provided")
     };
 
-    let sopts = config::build_session_options(&matches);
     let sess = build_session(sopts, input_file_path);
     let cfg = config::build_configuration(&sess);
     let odir = matches.opt_str("out-dir").map(|o| Path::new(o));
@@ -124,7 +128,7 @@ Additional help:
                              config::optgroups().as_slice()));
 }
 
-fn describe_warnings() {
+fn describe_lints() {
     println!("
 Available lint options:
     -W <foo>           Warn about <foo>
@@ -133,30 +137,32 @@ Available lint options:
     -F <foo>           Forbid <foo> (deny, and deny all overrides)
 ");
 
-    let lint_dict = lint::get_lint_dict();
-    let mut lint_dict = lint_dict.move_iter()
-                                 .map(|(k, v)| (v, k))
-                                 .collect::<Vec<(lint::LintSpec, &'static str)> >();
-    lint_dict.as_mut_slice().sort();
+    let mut builtin_specs = lint::builtin_lint_specs();
+    builtin_specs.sort_by(|x, y| {
+        match x.default_level.cmp(&y.default_level) {
+            Equal => x.name.cmp(&y.name),
+            r => r,
+        }
+    });
+
+    // FIXME: What if someone uses combining characters or East Asian fullwidth
+    // characters in a lint name?!?!?
+    let max_name_len = builtin_specs.iter()
+        .map(|&s| s.name.char_len())
+        .max().unwrap_or(0);
+    let padded = |x: &str| {
+        format!("{}{}", " ".repeat(max_name_len - x.char_len()), x)
+    };
 
-    let mut max_key = 0;
-    for &(_, name) in lint_dict.iter() {
-        max_key = cmp::max(name.len(), max_key);
-    }
-    fn padded(max: uint, s: &str) -> String {
-        format!("{}{}", " ".repeat(max - s.len()), s)
-    }
     println!("\nAvailable lint checks:\n");
-    println!("    {}  {:7.7s}  {}",
-             padded(max_key, "name"), "default", "meaning");
-    println!("    {}  {:7.7s}  {}\n",
-             padded(max_key, "----"), "-------", "-------");
-    for (spec, name) in lint_dict.move_iter() {
-        let name = name.replace("_", "-");
+    println!("    {}  {:7.7s}  {}", padded("name"), "default", "meaning");
+    println!("    {}  {:7.7s}  {}", padded("----"), "-------", "-------");
+    println!("");
+
+    for spec in builtin_specs.move_iter() {
+        let name = spec.name.replace("_", "-");
         println!("    {}  {:7.7s}  {}",
-                 padded(max_key, name.as_slice()),
-                 lint::level_to_str(spec.default),
-                 spec.desc);
+            padded(name.as_slice()), spec.default_level.as_str(), spec.desc);
     }
     println!("");
 }
@@ -214,12 +220,7 @@ pub fn handle_options(mut args: Vec<String>) -> Option<getopts::Matches> {
         return None;
     }
 
-    let lint_flags = matches.opt_strs("W").move_iter().collect::<Vec<_>>().append(
-                                    matches.opt_strs("warn").as_slice());
-    if lint_flags.iter().any(|x| x.as_slice() == "help") {
-        describe_warnings();
-        return None;
-    }
+    // Don't handle -W help here, because we might first load plugins.
 
     let r = matches.opt_strs("Z");
     if r.iter().any(|x| x.as_slice() == "help") {
diff --git a/src/librustc/driver/session.rs b/src/librustc/driver/session.rs
index e84c356b2d8..7f20059b657 100644
--- a/src/librustc/driver/session.rs
+++ b/src/librustc/driver/session.rs
@@ -106,16 +106,17 @@ impl Session {
         self.diagnostic().handler().unimpl(msg)
     }
     pub fn add_lint(&self,
-                    lint: lint::LintId,
+                    lint: &'static lint::Lint,
                     id: ast::NodeId,
                     sp: Span,
                     msg: String) {
+        let lint_id = lint::LintId::of(lint);
         let mut lints = self.lints.borrow_mut();
         match lints.find_mut(&id) {
-            Some(arr) => { arr.push((lint, sp, msg)); return; }
+            Some(arr) => { arr.push((lint_id, sp, msg)); return; }
             None => {}
         }
-        lints.insert(id, vec!((lint, sp, msg)));
+        lints.insert(id, vec!((lint_id, sp, msg)));
     }
     pub fn next_node_id(&self) -> ast::NodeId {
         self.reserve_node_ids(1)
diff --git a/src/librustc/front/feature_gate.rs b/src/librustc/front/feature_gate.rs
index 3d6b565fb86..b7c1ebcda98 100644
--- a/src/librustc/front/feature_gate.rs
+++ b/src/librustc/front/feature_gate.rs
@@ -409,7 +409,7 @@ pub fn check_crate(sess: &Session, krate: &ast::Crate) {
                                                      directive not necessary");
                         }
                         None => {
-                            sess.add_lint(lint::UnknownFeatures,
+                            sess.add_lint(lint::builtin::unknown_features,
                                           ast::CRATE_NODE_ID,
                                           mi.span,
                                           "unknown feature".to_string());
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index b933150dba4..0703b1fab60 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -127,6 +127,15 @@ pub mod lib {
     pub mod llvmdeps;
 }
 
+// A private module so that macro-expanded idents like
+// `::rustc::lint::Lint` will also work in `rustc` itself.
+//
+// `libstd` uses the same trick.
+#[doc(hidden)]
+mod rustc {
+    pub use lint;
+}
+
 pub fn main() {
     let args = std::os::args().iter()
                               .map(|x| x.to_string())
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 2ca4d3eb4e8..7fbefbf9416 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -19,7 +19,7 @@ use middle::privacy::ExportedItems;
 use middle::{typeck, ty, def, pat_util};
 use util::ppaux::{ty_to_str};
 use util::nodemap::NodeSet;
-use lint::{Context, LintPass};
+use lint::{Context, LintPass, LintArray};
 use lint;
 
 use std::cmp;
@@ -41,31 +41,17 @@ use syntax::codemap::Span;
 use syntax::parse::token;
 use syntax::{ast, ast_util, visit};
 
-/// Doesn't actually warn; just gathers information for use by
-/// checks in trans.
-#[deriving(Default)]
-pub struct GatherNodeLevels;
-
-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);
-                    },
-                    _ => { }
-                }
-            },
-            _ => { }
-        }
-    }
-}
+declare_lint!(while_true, Warn,
+    "suggest using `loop { }` instead of `while true { }`")
 
 #[deriving(Default)]
 pub struct WhileTrue;
 
 impl LintPass for WhileTrue {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(while_true)
+    }
+
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         match e.node {
             ast::ExprWhile(cond, _) => {
@@ -73,8 +59,7 @@ impl LintPass for WhileTrue {
                     ast::ExprLit(lit) => {
                         match lit.node {
                             ast::LitBool(true) => {
-                                cx.span_lint(lint::WhileTrue,
-                                             e.span,
+                                cx.span_lint(while_true, e.span,
                                              "denote infinite loops with loop \
                                               { ... }");
                             }
@@ -89,17 +74,23 @@ impl LintPass for WhileTrue {
     }
 }
 
+declare_lint!(unnecessary_typecast, Allow,
+    "detects unnecessary type casts, that can be removed")
+
 #[deriving(Default)]
 pub struct UnusedCasts;
 
 impl LintPass for UnusedCasts {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unnecessary_typecast)
+    }
+
     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");
+                    cx.span_lint(unnecessary_typecast, ty.span, "unnecessary type cast");
                 }
             }
             _ => ()
@@ -107,6 +98,15 @@ impl LintPass for UnusedCasts {
     }
 }
 
+declare_lint!(unsigned_negate, Warn,
+    "using an unary minus operator on unsigned type")
+
+declare_lint!(type_limits, Warn,
+    "comparisons made useless by limits of the types involved")
+
+declare_lint!(type_overflow, Warn,
+    "literal out of range for its type")
+
 pub struct TypeLimits {
     /// Id of the last visited negated expression
     negated_expr_id: ast::NodeId,
@@ -121,6 +121,10 @@ impl Default for TypeLimits {
 }
 
 impl LintPass for TypeLimits {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unsigned_negate, type_limits, type_overflow)
+    }
+
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         match e.node {
             ast::ExprUnary(ast::UnNeg, expr) => {
@@ -128,7 +132,7 @@ impl LintPass for TypeLimits {
                     ast::ExprLit(lit) => {
                         match lit.node {
                             ast::LitUint(..) => {
-                                cx.span_lint(lint::UnsignedNegate, e.span,
+                                cx.span_lint(unsigned_negate, e.span,
                                              "negation of unsigned int literal may \
                                              be unintentional");
                             },
@@ -139,7 +143,7 @@ impl LintPass for TypeLimits {
                         let t = ty::expr_ty(cx.tcx, expr);
                         match ty::get(t).sty {
                             ty::ty_uint(_) => {
-                                cx.span_lint(lint::UnsignedNegate, e.span,
+                                cx.span_lint(unsigned_negate, e.span,
                                              "negation of unsigned int variable may \
                                              be unintentional");
                             },
@@ -157,7 +161,7 @@ impl LintPass for TypeLimits {
             },
             ast::ExprBinary(binop, l, r) => {
                 if is_comparison(binop) && !check_limits(cx.tcx, binop, l, r) {
-                    cx.span_lint(lint::TypeLimits, e.span,
+                    cx.span_lint(type_limits, e.span,
                                  "comparison is useless due to type limits");
                 }
             },
@@ -178,7 +182,7 @@ impl LintPass for TypeLimits {
                             lit_val *= -1;
                         }
                         if  lit_val < min || lit_val > max {
-                            cx.span_lint(lint::TypeOverflow, e.span,
+                            cx.span_lint(type_overflow, e.span,
                                          "literal out of range for its type");
                         }
                     },
@@ -194,7 +198,7 @@ impl LintPass for TypeLimits {
                             _ => fail!()
                         };
                         if  lit_val < min || lit_val > max {
-                            cx.span_lint(lint::TypeOverflow, e.span,
+                            cx.span_lint(type_overflow, e.span,
                                          "literal out of range for its type");
                         }
                     },
@@ -300,30 +304,37 @@ impl LintPass for TypeLimits {
     }
 }
 
+declare_lint!(ctypes, Warn,
+    "proper use of libc types in foreign modules")
+
 #[deriving(Default)]
 pub struct CTypes;
 
 impl LintPass for CTypes {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(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");
+                            cx.span_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");
+                            cx.span_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");
+                                cx.span_lint(ctypes, ty.span,
+                                    "found enum type without foreign-function-safe \
+                                     representation annotation in foreign module");
                                 // hmm... this message could be more helpful
                             }
                         }
@@ -356,54 +367,64 @@ impl LintPass for CTypes {
     }
 }
 
+declare_lint!(managed_heap_memory, Allow,
+    "use of managed (@ type) heap memory")
+
+declare_lint!(owned_heap_memory, Allow,
+    "use of owned (Box type) heap memory")
+
+declare_lint!(heap_memory, Allow,
+    "use of any (Box type or @ type) heap memory")
+
 #[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;
-                    }
+        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
-            });
+                _ => ()
+            };
+            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_uniq > 0 {
+            let s = ty_to_str(cx.tcx, ty);
+            let m = format!("type uses owned (Box type) pointers: {}", s);
+            cx.span_lint(owned_heap_memory, span, m.as_slice());
+            cx.span_lint(heap_memory, 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());
-            }
+        if n_box > 0 {
+            let s = ty_to_str(cx.tcx, ty);
+            let m = format!("type uses managed (@ type) pointers: {}", s);
+            cx.span_lint(managed_heap_memory, span, m.as_slice());
+            cx.span_lint(heap_memory, span, m.as_slice());
         }
     }
 }
 
 impl LintPass for HeapMemory {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(managed_heap_memory, owned_heap_memory, heap_memory)
+    }
+
     fn check_item(&mut self, cx: &Context, it: &ast::Item) {
         match it.node {
             ast::ItemFn(..) |
@@ -434,6 +455,9 @@ impl LintPass for HeapMemory {
     }
 }
 
+declare_lint!(raw_pointer_deriving, Warn,
+    "uses of #[deriving] with raw pointers are rarely correct")
+
 struct RawPtrDerivingVisitor<'a> {
     cx: &'a Context<'a>
 }
@@ -442,7 +466,7 @@ 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 {
-            ast::TyPtr(..) => self.cx.span_lint(lint::RawPointerDeriving, ty.span, MSG),
+            ast::TyPtr(..) => self.cx.span_lint(raw_pointer_deriving, ty.span, MSG),
             _ => {}
         }
         visit::walk_ty(self, ty, ());
@@ -465,6 +489,10 @@ impl Default for RawPointerDeriving {
 }
 
 impl LintPass for RawPointerDeriving {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(raw_pointer_deriving)
+    }
+
     fn check_item(&mut self, cx: &Context, item: &ast::Item) {
         if !attr::contains_name(item.attrs.as_slice(), "automatically_derived") {
             return
@@ -495,10 +523,17 @@ impl LintPass for RawPointerDeriving {
     }
 }
 
+declare_lint!(unused_attribute, Warn,
+    "detects attributes that were not used by the compiler")
+
 #[deriving(Default)]
 pub struct UnusedAttribute;
 
 impl LintPass for UnusedAttribute {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unused_attribute)
+    }
+
     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
@@ -556,7 +591,7 @@ impl LintPass for UnusedAttribute {
         }
 
         if !attr::is_used(attr) {
-            cx.span_lint(lint::UnusedAttribute, attr.span, "unused attribute");
+            cx.span_lint(unused_attribute, 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 \
@@ -564,26 +599,30 @@ impl LintPass for UnusedAttribute {
                     ast::AttrInner => "crate-level attribute should be in the \
                                        root module",
                 };
-                cx.span_lint(lint::UnusedAttribute, attr.span, msg);
+                cx.span_lint(unused_attribute, attr.span, msg);
             }
         }
     }
 }
 
+declare_lint!(path_statement, Warn,
+    "path statements with no effect")
+
 #[deriving(Default)]
 pub struct PathStatement;
 
 impl LintPass for PathStatement {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(path_statement)
+    }
+
     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");
-                    }
-                    _ => {}
+                    ast::ExprPath(_) => cx.span_lint(path_statement, s.span,
+                                                     "path statement with no effect"),
+                    _ => ()
                 }
             }
             _ => ()
@@ -591,10 +630,20 @@ impl LintPass for PathStatement {
     }
 }
 
+declare_lint!(unused_must_use, Warn,
+    "unused result of a type flagged as #[must_use]")
+
+declare_lint!(unused_result, Allow,
+    "unused result of an expression in a statement")
+
 #[deriving(Default)]
-pub struct UnusedMustUse;
+pub struct UnusedResult;
+
+impl LintPass for UnusedResult {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unused_must_use, unused_result)
+    }
 
-impl LintPass for UnusedMustUse {
     fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
         let expr = match s.node {
             ast::StmtSemi(expr, _) => expr,
@@ -620,7 +669,7 @@ impl LintPass for UnusedMustUse {
                         ast_map::NodeItem(it) => {
                             if attr::contains_name(it.attrs.as_slice(),
                                                    "must_use") {
-                                cx.span_lint(lint::UnusedMustUse, s.span,
+                                cx.span_lint(unused_must_use, s.span,
                                              "unused result which must be used");
                                 warned = true;
                             }
@@ -630,7 +679,7 @@ impl LintPass for UnusedMustUse {
                 } 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,
+                            cx.span_lint(unused_must_use, s.span,
                                          "unused result which must be used");
                             warned = true;
                         }
@@ -640,21 +689,28 @@ impl LintPass for UnusedMustUse {
             _ => {}
         }
         if !warned {
-            cx.span_lint(lint::UnusedResult, s.span, "unused result");
+            cx.span_lint(unused_result, s.span, "unused result");
         }
     }
 }
 
+declare_lint!(deprecated_owned_vector, Allow,
+    "use of a `~[T]` vector")
+
 #[deriving(Default)]
 pub struct DeprecatedOwnedVector;
 
 impl LintPass for DeprecatedOwnedVector {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(deprecated_owned_vector)
+    }
+
     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,
+                    cx.span_lint(deprecated_owned_vector, e.span,
                                  "use of deprecated `~[]` vector; replaced by `std::vec::Vec`")
                 }
                 _ => {}
@@ -664,10 +720,17 @@ impl LintPass for DeprecatedOwnedVector {
     }
 }
 
+declare_lint!(non_camel_case_types, Warn,
+    "types, variants and traits should have camel case names")
+
 #[deriving(Default)]
 pub struct NonCamelCaseTypes;
 
 impl LintPass for NonCamelCaseTypes {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(non_camel_case_types)
+    }
+
     fn check_item(&mut self, cx: &Context, it: &ast::Item) {
         fn is_camel_case(ident: ast::Ident) -> bool {
             let ident = token::get_ident(ident);
@@ -690,8 +753,7 @@ impl LintPass for NonCamelCaseTypes {
             let s = token::get_ident(ident);
 
             if !is_camel_case(ident) {
-                cx.span_lint(lint::
-                    NonCamelCaseTypes, span,
+                cx.span_lint(non_camel_case_types, span,
                     format!("{} `{}` should have a camel case name such as `{}`",
                         sort, s, to_camel_case(s.get())).as_slice());
             }
@@ -744,6 +806,9 @@ fn method_context(cx: &Context, m: &ast::Method) -> MethodContext {
     }
 }
 
+declare_lint!(non_snake_case_functions, Warn,
+    "methods and functions should have snake case names")
+
 #[deriving(Default)]
 pub struct NonSnakeCaseFunctions;
 
@@ -785,7 +850,7 @@ impl NonSnakeCaseFunctions {
         let s = token::get_ident(ident);
 
         if !is_snake_case(ident) {
-            cx.span_lint(lint::NonSnakeCaseFunctions, span,
+            cx.span_lint(non_snake_case_functions, span,
                 format!("{} `{}` should have a snake case name such as `{}`",
                     sort, s, to_snake_case(s.get())).as_slice());
         }
@@ -793,6 +858,10 @@ impl NonSnakeCaseFunctions {
 }
 
 impl LintPass for NonSnakeCaseFunctions {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(non_snake_case_functions)
+    }
+
     fn check_fn(&mut self, cx: &Context,
                 fk: &visit::FnKind, _: &ast::FnDecl,
                 _: &ast::Block, span: Span, _: ast::NodeId) {
@@ -815,10 +884,17 @@ impl LintPass for NonSnakeCaseFunctions {
     }
 }
 
+declare_lint!(non_uppercase_statics, Allow,
+    "static constants should have uppercase identifiers")
+
 #[deriving(Default)]
 pub struct NonUppercaseStatics;
 
 impl LintPass for NonUppercaseStatics {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(non_uppercase_statics)
+    }
+
     fn check_item(&mut self, cx: &Context, it: &ast::Item) {
         match it.node {
             // only check static constants
@@ -828,7 +904,7 @@ impl LintPass for NonUppercaseStatics {
                 // 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,
+                    cx.span_lint(non_uppercase_statics, it.span,
                         format!("static constant `{}` should have an uppercase name \
                             such as `{}`", s.get(),
                             s.get().chars().map(|c| c.to_uppercase())
@@ -838,6 +914,18 @@ impl LintPass for NonUppercaseStatics {
             _ => {}
         }
     }
+}
+
+declare_lint!(non_uppercase_pattern_statics, Warn,
+    "static constants in match patterns should be all caps")
+
+#[deriving(Default)]
+pub struct NonUppercasePatternStatics;
+
+impl LintPass for NonUppercasePatternStatics {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(non_uppercase_pattern_statics)
+    }
 
     fn check_pat(&mut self, cx: &Context, p: &ast::Pat) {
         // Lint for constants that look like binding identifiers (#7526)
@@ -847,7 +935,7 @@ impl LintPass for NonUppercaseStatics {
                 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,
+                    cx.span_lint(non_uppercase_pattern_statics, path.span,
                         format!("static constant in pattern `{}` should have an uppercase \
                             name such as `{}`", s.get(),
                             s.get().chars().map(|c| c.to_uppercase())
@@ -859,10 +947,17 @@ impl LintPass for NonUppercaseStatics {
     }
 }
 
+declare_lint!(uppercase_variables, Warn,
+    "variable and structure field names should start with a lowercase character")
+
 #[deriving(Default)]
 pub struct UppercaseVariables;
 
 impl LintPass for UppercaseVariables {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(uppercase_variables)
+    }
+
     fn check_pat(&mut self, cx: &Context, p: &ast::Pat) {
         match &p.node {
             &ast::PatIdent(_, ref path, _) => {
@@ -873,9 +968,7 @@ impl LintPass for UppercaseVariables {
                         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,
+                            cx.span_lint(uppercase_variables, path.span,
                                 "variable names should start with a lowercase character");
                         }
                     }
@@ -893,8 +986,7 @@ impl LintPass for UppercaseVariables {
                 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,
+                        cx.span_lint(uppercase_variables, sf.span,
                             "structure field names should start with a lowercase character");
                     }
                 }
@@ -904,6 +996,9 @@ impl LintPass for UppercaseVariables {
     }
 }
 
+declare_lint!(unnecessary_parens, Warn,
+    "`if`, `match`, `while` and `return` do not need parentheses")
+
 #[deriving(Default)]
 pub struct UnnecessaryParens;
 
@@ -911,9 +1006,8 @@ 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())
+                cx.span_lint(unnecessary_parens, value.span,
+                    format!("unnecessary parentheses around {}", msg).as_slice())
             }
             _ => {}
         }
@@ -921,6 +1015,10 @@ impl UnnecessaryParens {
 }
 
 impl LintPass for UnnecessaryParens {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unnecessary_parens)
+    }
+
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         let (value, msg) = match e.node {
             ast::ExprIf(cond, _, _) => (cond, "`if` condition"),
@@ -949,18 +1047,24 @@ impl LintPass for UnnecessaryParens {
     }
 }
 
+declare_lint!(unused_unsafe, Warn,
+    "unnecessary use of an `unsafe` block")
+
 #[deriving(Default)]
 pub struct UnusedUnsafe;
 
 impl LintPass for UnusedUnsafe {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unused_unsafe)
+    }
+
     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");
+                    cx.span_lint(unused_unsafe, blk.span, "unnecessary `unsafe` block");
                 }
             }
             _ => ()
@@ -968,21 +1072,31 @@ impl LintPass for UnusedUnsafe {
     }
 }
 
+declare_lint!(unsafe_block, Allow,
+    "usage of an `unsafe` block")
+
 #[deriving(Default)]
 pub struct UnsafeBlock;
 
 impl LintPass for UnsafeBlock {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unsafe_block)
+    }
+
     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");
+                cx.span_lint(unsafe_block, blk.span, "usage of an `unsafe` block");
             }
             _ => ()
         }
     }
 }
 
+declare_lint!(unused_mut, Warn,
+    "detect mut variables which don't need to be mutable")
+
 #[deriving(Default)]
 pub struct UnusedMut;
 
@@ -1016,14 +1130,18 @@ impl UnusedMut {
         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");
+                cx.span_lint(unused_mut, cx.tcx.map.span(*v.get(0)),
+                    "variable does not need to be mutable");
             }
         }
     }
 }
 
 impl LintPass for UnusedMut {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unused_mut)
+    }
+
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         match e.node {
             ast::ExprMatch(_, ref arms) => {
@@ -1063,10 +1181,17 @@ enum Allocation {
     BoxAllocation
 }
 
+declare_lint!(unnecessary_allocation, Warn,
+    "detects unnecessary allocations that can be eliminated")
+
 #[deriving(Default)]
 pub struct UnnecessaryAllocation;
 
 impl LintPass for UnnecessaryAllocation {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(unnecessary_allocation)
+    }
+
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         // Warn if string and vector literals with sigils, or boxing expressions,
         // are immediately borrowed.
@@ -1086,27 +1211,24 @@ impl LintPass for 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");
+                                cx.span_lint(unnecessary_allocation, e.span,
+                                    "unnecessary allocation, the sigil can be removed");
                             }
                             (BoxAllocation,
                              Some(ty::AutoPtr(_, ast::MutImmutable))) => {
-                                report("unnecessary allocation, use & instead");
+                                cx.span_lint(unnecessary_allocation, e.span,
+                                    "unnecessary allocation, use & instead");
                             }
                             (BoxAllocation,
                              Some(ty::AutoPtr(_, ast::MutMutable))) => {
-                                report("unnecessary allocation, use &mut \
-                                        instead");
+                                cx.span_lint(unnecessary_allocation, e.span,
+                                    "unnecessary allocation, use &mut instead");
                             }
                             _ => ()
                         }
@@ -1119,6 +1241,9 @@ impl LintPass for UnnecessaryAllocation {
     }
 }
 
+declare_lint!(missing_doc, Allow,
+    "detects missing documentation for public members")
+
 pub struct MissingDoc {
     /// Set of nodes exported from this module.
     exported_items: Option<ExportedItems>,
@@ -1175,15 +1300,17 @@ impl MissingDoc {
             }
         });
         if !has_doc {
-            cx.span_lint(lint::MissingDoc,
-                         sp,
-                         format!("missing documentation for {}",
-                                 desc).as_slice());
+            cx.span_lint(missing_doc, sp,
+                format!("missing documentation for {}", desc).as_slice());
         }
     }
 }
 
 impl LintPass for MissingDoc {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(missing_doc)
+    }
+
     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() {
@@ -1268,12 +1395,25 @@ impl LintPass for MissingDoc {
     }
 }
 
+declare_lint!(deprecated, Warn,
+    "detects use of #[deprecated] items")
+
+declare_lint!(experimental, Warn,
+    "detects use of #[experimental] items")
+
+declare_lint!(unstable, Allow,
+    "detects use of #[unstable] items (incl. items with no stability attribute)")
+
 /// Checks for use of items with #[deprecated], #[experimental] and
 /// #[unstable] (or none of them) attributes.
 #[deriving(Default)]
 pub struct Stability;
 
 impl LintPass for Stability {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(deprecated, experimental, unstable)
+    }
+
     fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
         let id = match e.node {
             ast::ExprPath(..) | ast::ExprStruct(..) => {
@@ -1342,13 +1482,13 @@ impl LintPass for Stability {
 
         let (lint, label) = match stability {
             // no stability attributes == Unstable
-            None => (lint::Unstable, "unmarked"),
+            None => (unstable, "unmarked"),
             Some(attr::Stability { level: attr::Unstable, .. }) =>
-                    (lint::Unstable, "unstable"),
+                    (unstable, "unstable"),
             Some(attr::Stability { level: attr::Experimental, .. }) =>
-                    (lint::Experimental, "experimental"),
+                    (experimental, "experimental"),
             Some(attr::Stability { level: attr::Deprecated, .. }) =>
-                    (lint::Deprecated, "deprecated"),
+                    (deprecated, "deprecated"),
             _ => return
         };
 
@@ -1362,3 +1502,80 @@ impl LintPass for Stability {
         cx.span_lint(lint, e.span, msg.as_slice());
     }
 }
+
+/// Doesn't actually warn; just gathers information for use by
+/// checks in trans.
+#[deriving(Default)]
+pub struct GatherNodeLevels;
+
+impl LintPass for GatherNodeLevels {
+    fn get_lints(&self) -> LintArray {
+        lint_array!()
+    }
+
+    fn check_item(&mut self, cx: &Context, it: &ast::Item) {
+        match it.node {
+            ast::ItemEnum(..) => {
+                let lint_id = lint::LintId::of(variant_size_difference);
+                match cx.get_level_source(lint_id) {
+                    lvlsrc @ (lvl, _) if lvl != lint::Allow => {
+                        cx.insert_node_level(it.id, lint_id, lvlsrc);
+                    },
+                    _ => { }
+                }
+            },
+            _ => { }
+        }
+    }
+}
+
+declare_lint!(pub unused_imports, Warn,
+    "imports that are never used")
+
+declare_lint!(pub unnecessary_qualification, Allow,
+    "detects unnecessarily qualified names")
+
+declare_lint!(pub unrecognized_lint, Warn,
+    "unrecognized lint attribute")
+
+declare_lint!(pub unused_variable, Warn,
+    "detect variables which are not used in any way")
+
+declare_lint!(pub dead_assignment, Warn,
+    "detect assignments that will never be read")
+
+declare_lint!(pub dead_code, Warn,
+    "detect piece of code that will never be used")
+
+declare_lint!(pub visible_private_types, Warn,
+    "detect use of private types in exported type signatures")
+
+declare_lint!(pub unreachable_code, Warn,
+    "detects unreachable code")
+
+declare_lint!(pub warnings, Warn,
+    "mass-change the level for lints which produce warnings")
+
+declare_lint!(pub unknown_features, Deny,
+    "unknown features found in crate-level #[feature] directives")
+
+declare_lint!(pub unknown_crate_type, Deny,
+    "unknown crate type found in #[crate_type] directive")
+
+declare_lint!(pub variant_size_difference, Allow,
+    "detects enums with widely varying variant sizes")
+
+/// Does nothing as a lint pass, but registers some `Lint`s
+/// which are used by other parts of the compiler.
+#[deriving(Default)]
+pub struct HardwiredLints;
+
+impl LintPass for HardwiredLints {
+    fn get_lints(&self) -> LintArray {
+        lint_array!(
+            unused_imports, unnecessary_qualification, unrecognized_lint,
+            unused_variable, dead_assignment, dead_code, visible_private_types,
+            unreachable_code, warnings, unknown_features, unknown_crate_type,
+            variant_size_difference)
+    }
+}
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index 04d0e60cbf9..1664dd6f309 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -41,13 +41,13 @@
 //! this file, use `span_lint` instead of `add_lint`.
 
 #![allow(non_camel_case_types)]
+#![macro_escape]
 
-use driver::session;
-use middle::dead::DEAD_CODE_LINT_STR;
 use middle::privacy::ExportedItems;
 use middle::ty;
 use middle::typeck::astconv::AstConv;
 use middle::typeck::infer;
+use driver::session::Session;
 
 use std::collections::HashMap;
 use std::rc::Rc;
@@ -55,23 +55,83 @@ use std::gc::Gc;
 use std::to_str::ToStr;
 use std::cell::RefCell;
 use std::default::Default;
-use std::collections::SmallIntMap;
+use std::hash::Hash;
+use std::tuple::Tuple2;
+use std::hash;
 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, FnKind};
 use syntax::{ast, ast_util, visit};
 
-mod builtin;
+#[macro_export]
+macro_rules! lint_initializer (
+    ($name:ident, $level:ident, $desc:expr) => (
+        ::rustc::lint::Lint {
+            name: stringify!($name),
+            default_level: ::rustc::lint::$level,
+            desc: $desc,
+        }
+    )
+)
+
+#[macro_export]
+macro_rules! declare_lint (
+    // FIXME(#14660): deduplicate
+    (pub $name:ident, $level:ident, $desc:expr) => (
+        pub static $name: &'static ::rustc::lint::Lint
+            = &lint_initializer!($name, $level, $desc);
+    );
+    ($name:ident, $level:ident, $desc:expr) => (
+        static $name: &'static ::rustc::lint::Lint
+            = &lint_initializer!($name, $level, $desc);
+    );
+)
+
+#[macro_export]
+macro_rules! lint_array ( ($( $lint:expr ),*) => (
+    {
+        static array: LintArray = &[ $( $lint ),* ];
+        array
+    }
+))
 
-/// 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`.
+pub mod builtin;
+
+/// Specification of a single lint.
+pub struct Lint {
+    /// An identifier for the lint, written with underscores,
+    /// e.g. "unused_imports". This identifies the lint in
+    /// attributes and in command-line arguments. On the
+    /// command line, underscores become dashes.
+    pub name: &'static str,
+
+    /// Default level for the lint.
+    pub default_level: Level,
+
+    /// Description of the lint or the issue it detects,
+    /// e.g. "imports that are never used"
+    pub desc: &'static str,
+}
+
+type LintArray = &'static [&'static Lint];
+
+/// Trait for types providing lint checks. Each `check` method checks a single
+/// syntax node, and should not invoke methods recursively (unlike `Visitor`).
+/// By default they do nothing.
 //
-// FIXME: eliminate the duplication with `Visitor`
+// FIXME: eliminate the duplication with `Visitor`. But this also
+// contains a few lint-specific methods with no equivalent in `Visitor`.
 trait LintPass {
+    /// Get descriptions of the lints this `LintPass` object can emit.
+    ///
+    /// NB: there is no enforcement that the object only emits lints it registered.
+    /// And some `rustc` internal `LintPass`es register lints to be emitted by other
+    /// parts of the compiler. If you want enforced access restrictions for your
+    /// `Lint`, make it a private `static` item in its own module.
+    fn get_lints(&self) -> LintArray;
+
     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) { }
@@ -116,63 +176,37 @@ trait LintPass {
 
 type LintPassObject = Box<LintPass + 'static>;
 
-#[deriving(Clone, Show, PartialEq, PartialOrd, Eq, Ord, Hash)]
-pub enum LintId {
-    CTypes,
-    UnusedImports,
-    UnnecessaryQualification,
-    WhileTrue,
-    PathStatement,
-    UnrecognizedLint,
-    NonCamelCaseTypes,
-    NonUppercaseStatics,
-    NonUppercasePatternStatics,
-    NonSnakeCaseFunctions,
-    UppercaseVariables,
-    UnnecessaryParens,
-    TypeLimits,
-    TypeOverflow,
-    UnusedUnsafe,
-    UnsafeBlock,
-    UnusedAttribute,
-    UnknownFeatures,
-    UnknownCrateType,
-    UnsignedNegate,
-    VariantSizeDifference,
-
-    ManagedHeapMemory,
-    OwnedHeapMemory,
-    HeapMemory,
-
-    UnusedVariable,
-    DeadAssignment,
-    UnusedMut,
-    UnnecessaryAllocation,
-    DeadCode,
-    VisiblePrivateTypes,
-    UnnecessaryTypecast,
-
-    MissingDoc,
-    UnreachableCode,
-
-    Deprecated,
-    Experimental,
-    Unstable,
-
-    UnusedMustUse,
-    UnusedResult,
-
-    Warnings,
-
-    RawPointerDeriving,
+/// Identifies a lint known to the compiler.
+#[deriving(Clone)]
+pub struct LintId {
+    // Identity is based on pointer equality of this field.
+    lint: &'static Lint,
+}
+
+impl PartialEq for LintId {
+    fn eq(&self, other: &LintId) -> bool {
+        (self.lint as *Lint) == (other.lint as *Lint)
+    }
+}
+
+impl Eq for LintId { }
+
+impl<S: hash::Writer> Hash<S> for LintId {
+    fn hash(&self, state: &mut S) {
+        let ptr = self.lint as *Lint;
+        ptr.hash(state);
+    }
 }
 
-pub fn level_to_str(lv: Level) -> &'static str {
-    match lv {
-      Allow => "allow",
-      Warn => "warn",
-      Deny => "deny",
-      Forbid => "forbid"
+impl LintId {
+    pub fn of(lint: &'static Lint) -> LintId {
+        LintId {
+            lint: lint,
+        }
+    }
+
+    pub fn as_str(&self) -> &'static str {
+        self.lint.name
     }
 }
 
@@ -181,14 +215,26 @@ pub enum Level {
     Allow, Warn, Deny, Forbid
 }
 
-#[deriving(Clone, PartialEq, PartialOrd, Eq, Ord)]
-pub struct LintSpec {
-    pub default: Level,
-    pub lint: LintId,
-    pub desc: &'static str,
-}
+impl Level {
+    pub fn as_str(self) -> &'static str {
+        match self {
+            Allow => "allow",
+            Warn => "warn",
+            Deny => "deny",
+            Forbid => "forbid",
+        }
+    }
 
-pub type LintDict = HashMap<&'static str, LintSpec>;
+    pub fn from_str(x: &str) -> Option<Level> {
+        match x {
+            "allow" => Some(Allow),
+            "warn" => Some(Warn),
+            "deny" => Some(Deny),
+            "forbid" => Some(Forbid),
+            _ => None,
+        }
+    }
+}
 
 // this is public for the lints that run in trans
 #[deriving(PartialEq)]
@@ -198,331 +244,49 @@ pub enum LintSource {
     CommandLine
 }
 
-static lint_table: &'static [(&'static str, LintSpec)] = &[
-    ("ctypes",
-     LintSpec {
-        lint: CTypes,
-        desc: "proper use of libc types in foreign modules",
-        default: Warn
-     }),
-
-    ("unused_imports",
-     LintSpec {
-        lint: UnusedImports,
-        desc: "imports that are never used",
-        default: Warn
-     }),
-
-    ("unnecessary_qualification",
-     LintSpec {
-        lint: UnnecessaryQualification,
-        desc: "detects unnecessarily qualified names",
-        default: Allow
-     }),
-
-    ("while_true",
-     LintSpec {
-        lint: WhileTrue,
-        desc: "suggest using `loop { }` instead of `while true { }`",
-        default: Warn
-     }),
-
-    ("path_statement",
-     LintSpec {
-        lint: PathStatement,
-        desc: "path statements with no effect",
-        default: Warn
-     }),
-
-    ("unrecognized_lint",
-     LintSpec {
-        lint: UnrecognizedLint,
-        desc: "unrecognized lint attribute",
-        default: Warn
-     }),
-
-    ("non_camel_case_types",
-     LintSpec {
-        lint: NonCamelCaseTypes,
-        desc: "types, variants and traits should have camel case names",
-        default: Warn
-     }),
-
-    ("non_uppercase_statics",
-     LintSpec {
-         lint: NonUppercaseStatics,
-         desc: "static constants should have uppercase identifiers",
-         default: Allow
-     }),
-
-    ("non_uppercase_pattern_statics",
-     LintSpec {
-         lint: NonUppercasePatternStatics,
-         desc: "static constants in match patterns should be all caps",
-         default: Warn
-     }),
-
-    ("non_snake_case_functions",
-     LintSpec {
-         lint: NonSnakeCaseFunctions,
-         desc: "methods and functions should have snake case names",
-         default: Warn
-     }),
-
-    ("uppercase_variables",
-     LintSpec {
-         lint: UppercaseVariables,
-         desc: "variable and structure field names should start with a lowercase character",
-         default: Warn
-     }),
-
-     ("unnecessary_parens",
-     LintSpec {
-        lint: UnnecessaryParens,
-        desc: "`if`, `match`, `while` and `return` do not need parentheses",
-        default: Warn
-     }),
-
-    ("managed_heap_memory",
-     LintSpec {
-        lint: ManagedHeapMemory,
-        desc: "use of managed (@ type) heap memory",
-        default: Allow
-     }),
-
-    ("owned_heap_memory",
-     LintSpec {
-        lint: OwnedHeapMemory,
-        desc: "use of owned (Box type) heap memory",
-        default: Allow
-     }),
-
-    ("heap_memory",
-     LintSpec {
-        lint: HeapMemory,
-        desc: "use of any (Box type or @ type) heap memory",
-        default: Allow
-     }),
-
-    ("type_limits",
-     LintSpec {
-        lint: TypeLimits,
-        desc: "comparisons made useless by limits of the types involved",
-        default: Warn
-     }),
-
-    ("type_overflow",
-     LintSpec {
-        lint: TypeOverflow,
-        desc: "literal out of range for its type",
-        default: Warn
-     }),
-
-
-    ("unused_unsafe",
-     LintSpec {
-        lint: UnusedUnsafe,
-        desc: "unnecessary use of an `unsafe` block",
-        default: Warn
-    }),
-
-    ("unsafe_block",
-     LintSpec {
-        lint: UnsafeBlock,
-        desc: "usage of an `unsafe` block",
-        default: Allow
-    }),
-
-    ("unused_attribute",
-     LintSpec {
-         lint: UnusedAttribute,
-         desc: "detects attributes that were not used by the compiler",
-         default: Warn
-    }),
-
-    ("unused_variable",
-     LintSpec {
-        lint: UnusedVariable,
-        desc: "detect variables which are not used in any way",
-        default: Warn
-    }),
-
-    ("dead_assignment",
-     LintSpec {
-        lint: DeadAssignment,
-        desc: "detect assignments that will never be read",
-        default: Warn
-    }),
-
-    ("unnecessary_typecast",
-     LintSpec {
-        lint: UnnecessaryTypecast,
-        desc: "detects unnecessary type casts, that can be removed",
-        default: Allow,
-    }),
-
-    ("unused_mut",
-     LintSpec {
-        lint: UnusedMut,
-        desc: "detect mut variables which don't need to be mutable",
-        default: Warn
-    }),
-
-    ("unnecessary_allocation",
-     LintSpec {
-        lint: UnnecessaryAllocation,
-        desc: "detects unnecessary allocations that can be eliminated",
-        default: Warn
-    }),
-
-    (DEAD_CODE_LINT_STR,
-     LintSpec {
-        lint: DeadCode,
-        desc: "detect piece of code that will never be used",
-        default: Warn
-    }),
-    ("visible_private_types",
-     LintSpec {
-        lint: VisiblePrivateTypes,
-        desc: "detect use of private types in exported type signatures",
-        default: Warn
-    }),
-
-    ("missing_doc",
-     LintSpec {
-        lint: MissingDoc,
-        desc: "detects missing documentation for public members",
-        default: Allow
-    }),
-
-    ("unreachable_code",
-     LintSpec {
-        lint: UnreachableCode,
-        desc: "detects unreachable code",
-        default: Warn
-    }),
-
-    ("deprecated",
-     LintSpec {
-        lint: Deprecated,
-        desc: "detects use of #[deprecated] items",
-        default: Warn
-    }),
-
-    ("experimental",
-     LintSpec {
-        lint: Experimental,
-        desc: "detects use of #[experimental] items",
-        // FIXME #6875: Change to Warn after std library stabilization is complete
-        default: Allow
-    }),
-
-    ("unstable",
-     LintSpec {
-        lint: Unstable,
-        desc: "detects use of #[unstable] items (incl. items with no stability attribute)",
-        default: Allow
-    }),
-
-    ("warnings",
-     LintSpec {
-        lint: Warnings,
-        desc: "mass-change the level for lints which produce warnings",
-        default: Warn
-    }),
-
-    ("unknown_features",
-     LintSpec {
-        lint: UnknownFeatures,
-        desc: "unknown features found in crate-level #[feature] directives",
-        default: Deny,
-    }),
-
-    ("unknown_crate_type",
-    LintSpec {
-        lint: UnknownCrateType,
-        desc: "unknown crate type found in #[crate_type] directive",
-        default: Deny,
-    }),
-
-    ("unsigned_negate",
-    LintSpec {
-        lint: UnsignedNegate,
-        desc: "using an unary minus operator on unsigned type",
-        default: Warn
-    }),
-
-    ("variant_size_difference",
-    LintSpec {
-        lint: VariantSizeDifference,
-        desc: "detects enums with widely varying variant sizes",
-        default: Allow,
-    }),
-
-    ("unused_must_use",
-    LintSpec {
-        lint: UnusedMustUse,
-        desc: "unused result of a type flagged as #[must_use]",
-        default: Warn,
-    }),
-
-    ("unused_result",
-    LintSpec {
-        lint: UnusedResult,
-        desc: "unused result of an expression in a statement",
-        default: Allow,
-    }),
-
-    ("raw_pointer_deriving",
-     LintSpec {
-        lint: RawPointerDeriving,
-        desc: "uses of #[deriving] with raw pointers are rarely correct",
-        default: Warn,
-    }),
-];
-
-/*
-  Pass names should not contain a '-', as the compiler normalizes
-  '-' to '_' in command-line flags
- */
-pub fn get_lint_dict() -> LintDict {
-    lint_table.iter().map(|&(k, v)| (k, v)).collect()
-}
+pub type LevelSource = (Level, LintSource);
 
 struct Context<'a> {
-    /// All known lint modes (string versions)
-    dict: LintDict,
-    /// Current levels of each lint warning
-    cur: SmallIntMap<(Level, LintSource)>,
-    /// Context we're checking in (used to access fields like sess)
+    /// Trait objects for each lint pass.
+    lint_objects: Vec<RefCell<LintPassObject>>,
+
+    /// Lints indexed by name.
+    lints_by_name: HashMap<&'static str, LintId>,
+
+    /// Current levels of each lint, and where they were set.
+    levels: HashMap<LintId, LevelSource>,
+
+    /// Context we're checking in (used to access fields like sess).
     tcx: &'a ty::ctxt,
 
     /// 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.
-    level_stack: Vec<(LintId, Level, LintSource)>,
+    level_stack: Vec<(LintId, LevelSource)>,
 
     /// Level of lints for certain NodeIds, stored here because the body of
     /// the lint needs to run in trans.
-    node_levels: RefCell<HashMap<(ast::NodeId, LintId), (Level, LintSource)>>,
-
-    /// Trait objects for each lint.
-    lints: Vec<RefCell<LintPassObject>>,
+    node_levels: RefCell<HashMap<(ast::NodeId, LintId), LevelSource>>,
 }
 
-/// Convenience macro for calling a `LintPass` method on every lint in the context.
+/// Convenience macro for calling a `LintPass` method on every pass 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),*);
+    for obj in $cx.lint_objects.iter() {
+        obj.borrow_mut().$f($cx, $($args),*);
     }
 ))
 
-pub fn emit_lint(level: Level, src: LintSource, msg: &str, span: Span,
-                 lint_str: &str, tcx: &ty::ctxt) {
+/// Emit a lint as a `span_warn` or `span_err` (or not at all)
+/// according to `level`.  This lives outside of `Context` so
+/// it can be used by checks in trans that run after the main
+/// lint phase is finished.
+pub fn emit_lint(sess: &Session, lint: &'static Lint,
+                 lvlsrc: LevelSource, span: Span, msg: &str) {
+    let (level, source) = lvlsrc;
     if level == Allow { return }
 
     let mut note = None;
-    let msg = match src {
+    let msg = match source {
         Default => {
             format!("{}, #[{}({})] on by default", msg,
                 level_to_str(level), lint_str)
@@ -532,75 +296,50 @@ pub fn emit_lint(level: Level, src: LintSource, msg: &str, span: Span,
                 match level {
                     Warn => 'W', Deny => 'D', Forbid => 'F',
                     Allow => fail!()
-                }, lint_str.replace("_", "-"))
+                }, lint.name.replace("_", "-"))
         },
         Node(src) => {
             note = Some(src);
-            msg.to_str()
+            msg.to_string()
         }
     };
 
     match level {
-        Warn =>          { tcx.sess.span_warn(span, msg.as_slice()); }
-        Deny | Forbid => { tcx.sess.span_err(span, msg.as_slice());  }
+        Warn =>          { sess.span_warn(span, msg.as_slice()); }
+        Deny | Forbid => { sess.span_err(span, msg.as_slice());  }
         Allow => fail!(),
     }
 
-    for &span in note.iter() {
-        tcx.sess.span_note(span, "lint level defined here");
+    for span in note.move_iter() {
+        sess.span_note(span, "lint level defined here");
     }
 }
 
-pub fn lint_to_str(lint: LintId) -> &'static str {
-    for &(name, lspec) in lint_table.iter() {
-        if lspec.lint == lint {
-            return name;
-        }
-    }
-
-    fail!("unrecognized lint: {}", lint);
-}
-
 impl<'a> Context<'a> {
-    fn get_level(&self, lint: LintId) -> Level {
-        match self.cur.find(&(lint as uint)) {
-          Some(&(lvl, _)) => lvl,
-          None => Allow
+    fn get_level_source(&self, lint: LintId) -> LevelSource {
+        match self.levels.find(&lint) {
+            Some(&s) => s,
+            None => (Allow, Default),
         }
     }
 
-    fn get_source(&self, lint: LintId) -> LintSource {
-        match self.cur.find(&(lint as uint)) {
-          Some(&(_, src)) => src,
-          None => Default
-        }
-    }
-
-    fn set_level(&mut self, lint: LintId, level: Level, src: LintSource) {
-        if level == Allow {
-            self.cur.remove(&(lint as uint));
+    fn set_level(&mut self, lint: LintId, lvlsrc: LevelSource) {
+        if lvlsrc.val0() == Allow {
+            self.levels.remove(&lint);
         } else {
-            self.cur.insert(lint as uint, (level, src));
+            self.levels.insert(lint, lvlsrc);
         }
     }
 
-    fn lint_to_str(&self, lint: LintId) -> &'static str {
-        for (k, v) in self.dict.iter() {
-            if v.lint == lint {
-                return *k;
-            }
-        }
-        fail!("unregistered lint {}", lint);
-    }
-
-    fn span_lint(&self, lint: LintId, span: Span, msg: &str) {
-        let (level, src) = match self.cur.find(&(lint as uint)) {
-            None => { return }
-            Some(&(Warn, src)) => (self.get_level(Warnings), src),
+    fn span_lint(&self, lint: &'static Lint, span: Span, msg: &str) {
+        let (level, src) = match self.levels.find(&LintId::of(lint)) {
+            None => return,
+            Some(&(Warn, src))
+                => (self.get_level_source(LintId::of(builtin::warnings)).val0(), src),
             Some(&pair) => pair,
         };
 
-        emit_lint(level, src, msg, span, self.lint_to_str(lint), self.tcx);
+        emit_lint(&self.tcx.sess, lint, (level, src), span, msg);
     }
 
     /**
@@ -615,35 +354,22 @@ impl<'a> Context<'a> {
         // current dictionary of lint information. Along the way, keep a history
         // of what we changed so we can roll everything back after invoking the
         // specified closure
+        let lint_attrs = self.gather_lint_attrs(attrs);
         let mut pushed = 0u;
-        each_lint(&self.tcx.sess, attrs, |meta, level, lintname| {
-            match self.dict.find_equiv(&lintname) {
-                None => {
-                    self.span_lint(
-                        UnrecognizedLint,
-                        meta.span,
-                        format!("unknown `{}` attribute: `{}`",
-                                level_to_str(level), lintname).as_slice());
-                }
-                Some(lint) => {
-                    let lint = lint.lint;
-                    let now = self.get_level(lint);
-                    if now == Forbid && level != Forbid {
-                        self.tcx.sess.span_err(meta.span,
-                        format!("{}({}) overruled by outer forbid({})",
-                                level_to_str(level),
-                                lintname,
-                                lintname).as_slice());
-                    } else if now != level {
-                        let src = self.get_source(lint);
-                        self.level_stack.push((lint, now, src));
-                        pushed += 1;
-                        self.set_level(lint, level, Node(meta.span));
-                    }
-                }
+        for (lint_id, level, span) in lint_attrs.move_iter() {
+            let now = self.get_level_source(lint_id).val0();
+            if now == Forbid && level != Forbid {
+                let lint_name = lint_id.as_str();
+                self.tcx.sess.span_err(span,
+                format!("{}({}) overruled by outer forbid({})",
+                        level.as_str(), lint_name, lint_name).as_slice());
+            } else if now != level {
+                let src = self.get_level_source(lint_id).val1();
+                self.level_stack.push((lint_id, (now, src)));
+                pushed += 1;
+                self.set_level(lint_id, (level, Node(span)));
             }
-            true
-        });
+        }
 
         run_lints!(self, enter_lint_attrs, attrs);
         f(self);
@@ -651,8 +377,8 @@ impl<'a> Context<'a> {
 
         // rollback
         for _ in range(0, pushed) {
-            let (lint, lvl, src) = self.level_stack.pop().unwrap();
-            self.set_level(lint, lvl, src);
+            let (lint, lvlsrc) = self.level_stack.pop().unwrap();
+            self.set_level(lint, lvlsrc);
         }
     }
 
@@ -665,65 +391,49 @@ 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));
+    fn insert_node_level(&self, id: ast::NodeId, lint: LintId, lvlsrc: LevelSource) {
+        self.node_levels.borrow_mut().insert((id, lint), lvlsrc);
     }
-}
 
-/// Check that every lint from the list of attributes satisfies `f`.
-/// Return true if that's the case. Otherwise return false.
-pub fn each_lint(sess: &session::Session,
-                 attrs: &[ast::Attribute],
-                 f: |Gc<ast::MetaItem>, Level, InternedString| -> bool)
-                 -> bool {
-    let xs = [Allow, Warn, Deny, Forbid];
-    for &level in xs.iter() {
-        let level_name = level_to_str(level);
-        for attr in attrs.iter().filter(|m| m.check_name(level_name)) {
+    fn gather_lint_attrs(&mut self, attrs: &[ast::Attribute]) -> Vec<(LintId, Level, Span)> {
+        // Doing this as an iterator is messy due to multiple borrowing.
+        // Allocating and copying these should be quick.
+        let mut out = vec!();
+        for attr in attrs.iter() {
+            let level = match Level::from_str(attr.name().get()) {
+                None => continue,
+                Some(lvl) => lvl,
+            };
+
+            attr::mark_used(attr);
+
             let meta = attr.node.value;
             let metas = match meta.node {
                 ast::MetaList(_, ref metas) => metas,
                 _ => {
-                    sess.span_err(meta.span, "malformed lint attribute");
+                    self.tcx.sess.span_err(meta.span, "malformed lint attribute");
                     continue;
                 }
             };
+
             for meta in metas.iter() {
                 match meta.node {
-                    ast::MetaWord(ref lintname) => {
-                        if !f(*meta, level, (*lintname).clone()) {
-                            return false;
+                    ast::MetaWord(ref lint_name) => {
+                        match self.lints_by_name.find_equiv(lint_name) {
+                            Some(lint_id) => out.push((*lint_id, level, meta.span)),
+
+                            None => self.span_lint(builtin::unrecognized_lint,
+                                meta.span,
+                                format!("unknown `{}` attribute: `{}`",
+                                    level.as_str(), lint_name).as_slice()),
                         }
                     }
-                    _ => {
-                        sess.span_err(meta.span, "malformed lint attribute");
-                    }
+                    _ => self.tcx.sess.span_err(meta.span, "malformed lint attribute"),
                 }
             }
         }
+        out
     }
-    true
-}
-
-/// Check from a list of attributes if it contains the appropriate
-/// `#[level(lintname)]` attribute (e.g. `#[allow(dead_code)]).
-pub fn contains_lint(attrs: &[ast::Attribute],
-                     level: Level,
-                     lintname: &'static str)
-                     -> bool {
-    let level_name = level_to_str(level);
-    for attr in attrs.iter().filter(|m| m.name().equiv(&level_name)) {
-        if attr.meta_item_list().is_none() {
-            continue
-        }
-        let list = attr.meta_item_list().unwrap();
-        for meta_item in list.iter() {
-            if meta_item.name().equiv(&lintname) {
-                return true;
-            }
-        }
-    }
-    false
 }
 
 impl<'a> AstConv for Context<'a>{
@@ -912,59 +622,90 @@ impl<'a> Visitor<()> for Context<'a> {
     }
 }
 
+// Output any lints that were previously added to the session.
 impl<'a> IdVisitingOperation for Context<'a> {
     fn visit_id(&self, id: ast::NodeId) {
         match self.tcx.sess.lints.borrow_mut().pop(&id) {
             None => {}
-            Some(l) => {
-                for (lint, span, msg) in l.move_iter() {
-                    self.span_lint(lint, span, msg.as_slice())
+            Some(lints) => {
+                for (lint_id, span, msg) in lints.move_iter() {
+                    self.span_lint(lint_id.lint, span, msg.as_slice())
                 }
             }
         }
     }
 }
 
-pub fn check_crate(tcx: &ty::ctxt,
-                   exported_items: &ExportedItems,
-                   krate: &ast::Crate) {
+fn builtin_lints() -> Vec<Box<LintPass>> {
     macro_rules! builtin_lints (( $($name:ident),*, ) => (
         vec!($(
             {
                 let obj: builtin::$name = Default::default();
-                RefCell::new(box obj as LintPassObject)
+                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,
-    );
+    builtin_lints!(
+        WhileTrue, UnusedCasts, TypeLimits, CTypes, HeapMemory,
+        RawPointerDeriving, UnusedAttribute, PathStatement,
+        UnusedResult, DeprecatedOwnedVector, NonCamelCaseTypes,
+        NonSnakeCaseFunctions, NonUppercaseStatics,
+        NonUppercasePatternStatics, UppercaseVariables,
+        UnnecessaryParens, UnusedUnsafe, UnsafeBlock, UnusedMut,
+        UnnecessaryAllocation, MissingDoc, Stability,
+
+        GatherNodeLevels, HardwiredLints,
+    )
+}
+
+/// Get specs for all builtin lints.  Used for `-W help`.
+pub fn builtin_lint_specs() -> Vec<&'static Lint> {
+    builtin_lints().move_iter()
+        .flat_map(|x| x.get_lints().iter().map(|&y| y))
+        .collect()
+}
+
+pub fn check_crate(tcx: &ty::ctxt,
+                   exported_items: &ExportedItems,
+                   krate: &ast::Crate) {
+    let lints = builtin_lints().move_iter().map(|x| RefCell::new(x)).collect();
 
     let mut cx = Context {
-        dict: get_lint_dict(),
-        cur: SmallIntMap::new(),
+        lint_objects: lints,
+        lints_by_name: HashMap::new(),
+        levels: HashMap::new(),
         tcx: tcx,
         level_stack: Vec::new(),
         node_levels: RefCell::new(HashMap::new()),
-        lints: builtin_lints,
     };
 
-    // Install default lint levels, followed by the command line levels, and
-    // then actually visit the whole crate.
-    for (_, spec) in cx.dict.iter() {
-        if spec.default != Allow {
-            cx.cur.insert(spec.lint as uint, (spec.default, Default));
+    // Index the lints by name, and set the default levels.
+    for obj in cx.lint_objects.iter() {
+        for &lint in obj.borrow_mut().get_lints().iter() {
+            let id = LintId::of(lint);
+            if !cx.lints_by_name.insert(lint.name, id) {
+                cx.tcx.sess.err(format!("duplicate specification of lint {}",
+                    lint.name).as_slice());
+            }
+            if lint.default_level != Allow {
+                cx.levels.insert(id, (lint.default_level, Default));
+            }
         }
     }
-    for &(lint, level) in tcx.sess.opts.lint_opts.iter() {
-        cx.set_level(lint, level, CommandLine);
+
+    // Set command line lint levels.
+    for &(ref lint_name, level) in tcx.sess.opts.lint_opts.iter() {
+        match cx.lints_by_name.find_equiv(&lint_name.as_slice()) {
+            Some(&lint_id) => cx.set_level(lint_id, (level, CommandLine)),
+            None => cx.tcx.sess.err(format!("unknown {} flag: {}",
+                level.as_str(), lint_name).as_slice()),
+        }
     }
+
+    tcx.sess.abort_if_errors();
+
+    // Visit the whole crate.
     cx.with_lint_attrs(krate.attrs.as_slice(), |cx| {
         cx.visit_id(ast::CRATE_NODE_ID);
         cx.visit_ids(|v| {
@@ -983,8 +724,10 @@ pub fn check_crate(tcx: &ty::ctxt,
     // in the iteration code.
     for (id, v) in tcx.sess.lints.borrow().iter() {
         for &(lint, span, ref msg) in v.iter() {
-            tcx.sess.span_bug(span, format!("unprocessed lint {} at {}: {}",
-                                            lint, tcx.map.node_to_str(*id), *msg).as_slice())
+            tcx.sess.span_bug(span,
+                format!("unprocessed lint {} at {}: {}",
+                    lint.as_str(), tcx.map.node_to_str(*id), *msg)
+                .as_slice())
         }
     }
 
diff --git a/src/librustc/middle/dead.rs b/src/librustc/middle/dead.rs
index f5b2e3c7e77..98c045dd8a4 100644
--- a/src/librustc/middle/dead.rs
+++ b/src/librustc/middle/dead.rs
@@ -13,7 +13,7 @@
 // from live codes are live, and everything else is dead.
 
 use middle::def;
-use lint::{Allow, contains_lint, DeadCode};
+use lint;
 use middle::privacy;
 use middle::ty;
 use middle::typeck;
@@ -23,14 +23,13 @@ use std::collections::HashSet;
 use syntax::ast;
 use syntax::ast_map;
 use syntax::ast_util::{local_def, is_local};
+use syntax::attr::AttrMetaMethods;
 use syntax::attr;
 use syntax::codemap;
 use syntax::parse::token;
 use syntax::visit::Visitor;
 use syntax::visit;
 
-pub static DEAD_CODE_LINT_STR: &'static str = "dead_code";
-
 // Any local node that may call something in its body block should be
 // explored. For example, if it's a live NodeItem that is a
 // function, then we should explore its block to check for codes that
@@ -266,8 +265,24 @@ impl<'a> Visitor<MarkSymbolVisitorContext> for MarkSymbolVisitor<'a> {
 }
 
 fn has_allow_dead_code_or_lang_attr(attrs: &[ast::Attribute]) -> bool {
-    contains_lint(attrs, Allow, DEAD_CODE_LINT_STR)
-    || attr::contains_name(attrs.as_slice(), "lang")
+    if attr::contains_name(attrs.as_slice(), "lang") {
+        return true;
+    }
+
+    // FIXME: use the lint attr parsing already in rustc::lint
+    for attr in attrs.iter().filter(|a| a.check_name("allow")) {
+        match attr.node.value.node {
+            ast::MetaList(_, ref metas) => for meta in metas.iter() {
+                match meta.node {
+                    ast::MetaWord(ref name) if name.get() == "dead_code"
+                        => return true,
+                    _ => (),
+                }
+            },
+            _ => (),
+        }
+    }
+    false
 }
 
 // This visitor seeds items that
@@ -446,7 +461,7 @@ impl<'a> DeadVisitor<'a> {
                       ident: ast::Ident) {
         self.tcx
             .sess
-            .add_lint(DeadCode,
+            .add_lint(lint::builtin::dead_code,
                       id,
                       span,
                       format!("code is never used: `{}`",
diff --git a/src/librustc/middle/liveness.rs b/src/librustc/middle/liveness.rs
index a556f4d6b8d..5841a13280b 100644
--- a/src/librustc/middle/liveness.rs
+++ b/src/librustc/middle/liveness.rs
@@ -107,7 +107,7 @@ use middle::freevars;
 use middle::mem_categorization::Typer;
 use middle::pat_util;
 use middle::ty;
-use lint::{UnusedVariable, DeadAssignment};
+use lint;
 use util::nodemap::NodeMap;
 
 use std::fmt;
@@ -1560,11 +1560,11 @@ impl<'a> Liveness<'a> {
                 };
 
                 if is_assigned {
-                    self.ir.tcx.sess.add_lint(UnusedVariable, id, sp,
+                    self.ir.tcx.sess.add_lint(lint::builtin::unused_variable, id, sp,
                         format!("variable `{}` is assigned to, but never used",
                                 *name));
                 } else {
-                    self.ir.tcx.sess.add_lint(UnusedVariable, id, sp,
+                    self.ir.tcx.sess.add_lint(lint::builtin::unused_variable, id, sp,
                         format!("unused variable: `{}`", *name));
                 }
             }
@@ -1582,7 +1582,7 @@ impl<'a> Liveness<'a> {
         if self.live_on_exit(ln, var).is_none() {
             let r = self.should_warn(var);
             for name in r.iter() {
-                self.ir.tcx.sess.add_lint(DeadAssignment, id, sp,
+                self.ir.tcx.sess.add_lint(lint::builtin::dead_assignment, id, sp,
                     format!("value assigned to `{}` is never read", *name));
             }
         }
diff --git a/src/librustc/middle/privacy.rs b/src/librustc/middle/privacy.rs
index 777b9a55e4b..86a24838850 100644
--- a/src/librustc/middle/privacy.rs
+++ b/src/librustc/middle/privacy.rs
@@ -1394,7 +1394,7 @@ impl<'a> Visitor<()> for VisiblePrivateTypesVisitor<'a> {
             ast::TyPath(ref p, _, path_id) => {
                 if self.path_is_private_type(path_id) {
                     self.tcx.sess.add_lint(
-                        lint::VisiblePrivateTypes,
+                        lint::builtin::visible_private_types,
                         path_id, p.span,
                         "private type in exported type \
                          signature".to_string());
diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs
index c2a660677a5..f0abcc27282 100644
--- a/src/librustc/middle/resolve.rs
+++ b/src/librustc/middle/resolve.rs
@@ -15,9 +15,9 @@ use metadata::csearch;
 use metadata::decoder::{DefLike, DlDef, DlField, DlImpl};
 use middle::def::*;
 use middle::lang_items::LanguageItems;
-use lint::{UnnecessaryQualification, UnusedImports};
 use middle::pat_util::pat_bindings;
 use middle::subst::{ParamSpace, FnSpace, TypeSpace};
+use lint;
 use util::nodemap::{NodeMap, DefIdSet, FnvHashMap};
 
 use syntax::ast::*;
@@ -4632,7 +4632,7 @@ impl<'a> Resolver<'a> {
             match (def, unqualified_def) {
                 (Some((d, _)), Some((ud, _))) if d == ud => {
                     self.session
-                        .add_lint(UnnecessaryQualification,
+                        .add_lint(lint::builtin::unnecessary_qualification,
                                   id,
                                   path.span,
                                   "unnecessary qualification".to_string());
@@ -5487,7 +5487,7 @@ impl<'a> Resolver<'a> {
                         if !self.used_imports.contains(&(id, TypeNS)) &&
                            !self.used_imports.contains(&(id, ValueNS)) {
                             self.session
-                                .add_lint(UnusedImports,
+                                .add_lint(lint::builtin::unused_imports,
                                           id,
                                           p.span,
                                           "unused import".to_string());
@@ -5511,7 +5511,7 @@ impl<'a> Resolver<'a> {
 
         if !self.used_imports.contains(&(id, TypeNS)) &&
            !self.used_imports.contains(&(id, ValueNS)) {
-            self.session.add_lint(UnusedImports,
+            self.session.add_lint(lint::builtin::unused_imports,
                                   id,
                                   span,
                                   "unused import".to_string());
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index e1416380f35..5513a44a2ab 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -1552,48 +1552,50 @@ fn trans_enum_def(ccx: &CrateContext, enum_definition: &ast::EnumDef,
 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &ast::EnumDef, sp: Span, id: ast::NodeId) {
     let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
 
-    let (lvl, src) = ccx.tcx.node_lint_levels.borrow()
-                        .find(&(id, lint::VariantSizeDifference))
-                        .map_or((lint::Allow, lint::Default), |&(lvl,src)| (lvl, src));
-
-    if lvl != lint::Allow {
-        let avar = adt::represent_type(ccx, ty::node_id_to_type(ccx.tcx(), id));
-        match *avar {
-            adt::General(_, ref variants) => {
-                for var in variants.iter() {
-                    let mut size = 0;
-                    for field in var.fields.iter().skip(1) {
-                        // skip the discriminant
-                        size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
+    let levels = ccx.tcx.node_lint_levels.borrow();
+    match levels.find(&(id, lint::LintId::of(lint::builtin::variant_size_difference))) {
+        None | Some(&(lint::Allow, _)) => (),
+        Some(&lvlsrc) => {
+            let avar = adt::represent_type(ccx, ty::node_id_to_type(ccx.tcx(), id));
+            match *avar {
+                adt::General(_, ref variants) => {
+                    for var in variants.iter() {
+                        let mut size = 0;
+                        for field in var.fields.iter().skip(1) {
+                            // skip the discriminant
+                            size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
+                        }
+                        sizes.push(size);
                     }
-                    sizes.push(size);
-                }
-            },
-            _ => { /* its size is either constant or unimportant */ }
-        }
+                },
+                _ => { /* its size is either constant or unimportant */ }
+            }
 
-        let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
-            |(l, s, li), (idx, &size)|
-                if size > l {
-                    (size, l, idx)
-                } else if size > s {
-                    (l, size, li)
-                } else {
-                    (l, s, li)
-                }
-        );
-
-        // we only warn if the largest variant is at least thrice as large as
-        // the second-largest.
-        if largest > slargest * 3 && slargest > 0 {
-            lint::emit_lint(lvl, src,
-                            format!("enum variant is more than three times larger \
-                                    ({} bytes) than the next largest (ignoring padding)",
-                                    largest).as_slice(),
-                            sp, lint::lint_to_str(lint::VariantSizeDifference), ccx.tcx());
-
-            ccx.sess().span_note(enum_def.variants.get(largest_index).span,
-                                 "this variant is the largest");
+            let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
+                |(l, s, li), (idx, &size)|
+                    if size > l {
+                        (size, l, idx)
+                    } else if size > s {
+                        (l, size, li)
+                    } else {
+                        (l, s, li)
+                    }
+            );
+
+            // we only warn if the largest variant is at least thrice as large as
+            // the second-largest.
+            if largest > slargest * 3 && slargest > 0 {
+                // Use lint::emit_lint rather than sess.add_lint because the lint-printing
+                // pass for the latter already ran.
+                lint::emit_lint(&ccx.tcx().sess, lint::builtin::variant_size_difference,
+                                lvlsrc, sp,
+                                format!("enum variant is more than three times larger \
+                                        ({} bytes) than the next largest (ignoring padding)",
+                                        largest).as_slice());
+
+                ccx.sess().span_note(enum_def.variants.get(largest_index).span,
+                                     "this variant is the largest");
+            }
         }
     }
 }
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 97a884ae11d..b0e838a442b 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -368,7 +368,7 @@ pub struct ctxt {
     pub dependency_formats: RefCell<dependency_format::Dependencies>,
 
     pub node_lint_levels: RefCell<HashMap<(ast::NodeId, lint::LintId),
-                                          (lint::Level, lint::LintSource)>>,
+                                          lint::LevelSource>>,
 
     /// The types that must be asserted to be the same size for `transmute`
     /// to be valid. We gather up these restrictions in the intrinsicck pass
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index 82cd43f9eee..bb781307668 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -79,7 +79,6 @@ type parameter).
 
 use middle::const_eval;
 use middle::def;
-use lint::UnreachableCode;
 use middle::pat_util::pat_id_map;
 use middle::pat_util;
 use middle::subst;
@@ -111,6 +110,7 @@ use middle::typeck::{require_same_types, vtable_map};
 use middle::typeck::{MethodCall, MethodMap};
 use middle::typeck::{TypeAndSubsts};
 use middle::lang_items::TypeIdLangItem;
+use lint;
 use util::common::{block_query, indenter, loop_query};
 use util::ppaux;
 use util::ppaux::{UserString, Repr};
@@ -3416,7 +3416,7 @@ pub fn check_block_with_expected(fcx: &FnCtxt,
                 fcx.ccx
                    .tcx
                    .sess
-                   .add_lint(UnreachableCode,
+                   .add_lint(lint::builtin::unreachable_code,
                              s_id,
                              s.span,
                              "unreachable statement".to_string());
@@ -3443,7 +3443,7 @@ pub fn check_block_with_expected(fcx: &FnCtxt,
                 fcx.ccx
                    .tcx
                    .sess
-                   .add_lint(UnreachableCode,
+                   .add_lint(lint::builtin::unreachable_code,
                              e.id,
                              e.span,
                              "unreachable expression".to_string());
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 3a481abc775..ef8367dfc76 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -75,11 +75,13 @@ fn get_ast_and_resolve(cpath: &Path, libs: HashSet<Path>, cfgs: Vec<String>)
 
     let input = FileInput(cpath.clone());
 
+    let warning_lint = lint::builtin::warnings.name.to_string();
+
     let sessopts = driver::config::Options {
         maybe_sysroot: Some(os::self_exe_path().unwrap().dir_path()),
         addl_lib_search_paths: RefCell::new(libs),
         crate_types: vec!(driver::config::CrateTypeRlib),
-        lint_opts: vec!((lint::Warnings, lint::Allow)),
+        lint_opts: vec!((warning_lint, lint::Allow)),
         ..rustc::driver::config::basic_options().clone()
     };