rustc: Add lint for obsolete attributes

This also moves `#[auto_{en,de}code]` checker from syntax to lint.

Author: klutzy

src/librustc/middle/lint.rs

@@ -803,6 +803,11 @@ fn check_heap_item(cx: &Context, it: &ast::item) {
 // also make error on obsolete attributes for less confusion.
 fn check_item_attribute_usage(cx: &Context, it: &ast::item) {
     let crate_attrs = ["crate_type", "link", "feature", "no_uv", "no_main", "no_std"];
+    let obsolete_attrs = [
+        ("abi", "extern \"abi\" fn"),
+        ("auto_encode", "#[deriving(Encodable)]"),
+        ("auto_decode", "#[deriving(Decodable)]"),
+    ];
 
     for attr in it.attrs.iter() {
         let name = attr.node.value.name();
@@ -816,6 +821,13 @@ fn check_item_attribute_usage(cx: &Context, it: &ast::item) {
                 cx.span_lint(attribute_usage, attr.span, msg);
             }
         }
+
+        for &(obs_attr, obs_alter) in obsolete_attrs.iter() {
+            if name.equiv(&obs_attr) {
+                cx.span_lint(attribute_usage, attr.span,
+                             format!("obsolete attribute: use `{:s}` instead", obs_alter));
+            }
+        }
     }
 }
 

src/libstd/io/native/process.rs

@@ -365,7 +365,6 @@ fn spawn_process_os(prog: &str, args: &[~str],
     use libc::funcs::bsd44::getdtablesize;
 
     mod rustrt {
-        #[abi = "cdecl"]
         extern {
             pub fn rust_unset_sigprocmask();
         }

src/libsyntax/ext/auto_encode.rs

@@ -143,7 +143,7 @@ pub enum MacResult {
 }
 
 pub enum SyntaxExtension {
-    // #[auto_encode] and such
+    // #[deriving] and such
     ItemDecorator(ItemDecorator),
 
     // Token-tree expanders
@@ -229,12 +229,6 @@ pub fn syntax_expander_table() -> SyntaxEnv {
     syntax_expanders.insert(intern(&"format_args"),
                             builtin_normal_tt_no_ctxt(
                                 ext::format::expand_args));
-    syntax_expanders.insert(
-        intern(&"auto_encode"),
-        @SE(ItemDecorator(ext::auto_encode::expand_auto_encode)));
-    syntax_expanders.insert(
-        intern(&"auto_decode"),
-        @SE(ItemDecorator(ext::auto_encode::expand_auto_decode)));
     syntax_expanders.insert(intern(&"env"),
                             builtin_normal_tt_no_ctxt(
                                     ext::env::expand_env));

src/libsyntax/ext/base.rs

@@ -83,7 +83,6 @@ pub mod ext {
     pub mod concat;
     pub mod concat_idents;
     pub mod log_syntax;
-    pub mod auto_encode;
     pub mod source_util;
 
     pub mod trace_macros;