Re-implement lint with less emphasis on item ids

This way it's much easier to add lints throughout compilation correctly, and
functions on impls can alter the way lints are emitted.

src/libcore/hashmap.rs

@@ -17,7 +17,6 @@ use container::{Container, Mutable, Map, Set};
 use cmp::{Eq, Equiv};
 use hash::Hash;
 use old_iter::BaseIter;
-use hash::Hash;
 use old_iter;
 use option::{None, Option, Some};
 use rand::RngUtil;

src/librustc/back/link.rs

@@ -171,7 +171,6 @@ pub mod write {
     use back::link::{output_type_assembly, output_type_bitcode};
     use back::link::{output_type_exe, output_type_llvm_assembly};
     use back::link::{output_type_object};
-    use back::link::output_type;
     use driver::session::Session;
     use driver::session;
     use lib::llvm::llvm;

src/librustc/driver/driver.rs

@@ -22,6 +22,7 @@ use middle;
 use util::common::time;
 use util::ppaux;
 
+use core::hashmap::HashMap;
 use core::int;
 use core::io;
 use core::os;
@@ -200,9 +201,6 @@ pub fn compile_rest(sess: Session,
     crate = time(time_passes, ~"core injection", ||
         front::core_inject::maybe_inject_libcore_ref(sess, crate));
 
-    time(time_passes, ~"building lint settings table", ||
-        lint::build_settings_crate(sess, crate));
-
     let ast_map = time(time_passes, ~"ast indexing", ||
             syntax::ast_map::map_crate(sess.diagnostic(), crate));
 
@@ -709,7 +707,6 @@ pub fn build_session_(sopts: @session::options,
         &sopts.maybe_sysroot,
         sopts.target_triple,
         /*bad*/copy sopts.addl_lib_search_paths);
-    let lint_settings = lint::mk_lint_settings();
     @Session_ {
         targ_cfg: target_cfg,
         opts: sopts,
@@ -723,7 +720,7 @@ pub fn build_session_(sopts: @session::options,
         filesearch: filesearch,
         building_library: @mut false,
         working_dir: os::getcwd(),
-        lint_settings: lint_settings
+        lints: @mut HashMap::new(),
     }
 }
 

src/librustc/driver/session.rs

@@ -26,6 +26,8 @@ use syntax::{ast, codemap};
 use syntax::abi;
 use syntax;
 
+use core::hashmap::HashMap;
+
 #[deriving(Eq)]
 pub enum os { os_win32, os_macos, os_linux, os_android, os_freebsd, }
 
@@ -170,7 +172,7 @@ pub struct Session_ {
     filesearch: @filesearch::FileSearch,
     building_library: @mut bool,
     working_dir: Path,
-    lint_settings: lint::LintSettings
+    lints: @mut HashMap<ast::node_id, ~[(lint::lint, codemap::span, ~str)]>,
 }
 
 pub type Session = @Session_;
@@ -230,15 +232,12 @@ pub impl Session_ {
           }
         }
     }
-    fn span_lint(@self, lint_mode: lint::lint,
-                 expr_id: ast::node_id,
-                 item_id: ast::node_id,
-                 span: span,
-                 msg: &str) {
-        let level = lint::get_lint_settings_level(
-            self.lint_settings, lint_mode, expr_id, item_id);
-        let msg = fmt!("%s [-W %s]", msg, lint::get_lint_name(lint_mode));
-        self.span_lint_level(level, span, msg);
+    fn add_lint(@self, lint: lint::lint, id: ast::node_id, sp: span, msg: ~str) {
+        match self.lints.find_mut(&id) {
+            Some(arr) => { arr.push((lint, sp, msg)); return; }
+            None => {}
+        }
+        self.lints.insert(id, ~[(lint, sp, msg)]);
     }
     fn next_node_id(@self) -> ast::node_id {
         return syntax::parse::next_node_id(self.parse_sess);