From e8231672d048cc81b3029b3ef0058a221a639edc Mon Sep 17 00:00:00 2001
From: Nick Fitzgerald <fitzgen@gmail.com>
Date: Sun, 7 Jun 2015 10:47:51 -0700
Subject: [PATCH] WIP more tracing plugin

---
 .gitignore                  |  1 +
 src/lib.rs                  | 33 +++++----------------------------
 src/trace_plugin.rs         | 29 +++++++++++++++++------------
 tests/simple_plugin_test.rs |  7 +++++--
 4 files changed, 28 insertions(+), 42 deletions(-)

diff --git a/.gitignore b/.gitignore
index a9d37c5..0723636 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 target
 Cargo.lock
+*.racertmp
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 1211149..e39a1e6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -151,6 +151,7 @@
 #![feature(core)]
 #![feature(custom_derive)]
 #![feature(filling_drop)]
+#![feature(optin_builtin_traits)]
 #![feature(plugin)]
 #![feature(plugin_registrar)]
 #![feature(quote)]
@@ -796,17 +797,17 @@ impl<T> CcBoxPtr<T> for Weak<T> {
     }
 }
 
-pub type Tracer = FnMut(&CcTrace);
+pub type Tracer = FnMut(&Trace);
 
-pub trait CcTrace: fmt::Debug {
-    fn trace(&self, tracer: &mut Tracer);
+pub trait Trace: fmt::Debug {
+    fn trace(&self, _tracer: &mut Tracer);
 }
 
 #[cfg(test)]
 mod tests {
     #![plugin(bacon_rajan_cc)]
 
-    use super::{Cc, CcTrace, Weak, weak_count, strong_count};
+    use super::{Cc, Weak, weak_count, strong_count};
     use std::boxed::Box;
     use std::cell::RefCell;
     use std::option::Option;
@@ -815,30 +816,6 @@ mod tests {
     use std::mem::drop;
     use std::clone::Clone;
 
-    // trace_macros!(true);
-
-    // #[derive(CcTrace, Debug)]
-    // struct CycleCollected {
-    //     a: Cc<u32>,
-    //     b: Cc<String>,
-    // }
-
-    // trace_macros!(false);
-
-    // #[test]
-    // fn test_plugin() {
-    //     let x = CycleCollected {
-    //         a: Cc::new(5),
-    //         b: Cc::new("hello".into()),
-    //     };
-
-    //     CcTrace::trace(&x, &mut |v| {
-    //         println!("traced {:?}", v);
-    //     });
-
-    //     assert!(false);
-    // }
-
     // Tests copied from `Rc<T>`.
 
     #[test]
diff --git a/src/trace_plugin.rs b/src/trace_plugin.rs
index 46302cd..cd87a48 100644
--- a/src/trace_plugin.rs
+++ b/src/trace_plugin.rs
@@ -21,8 +21,8 @@
 
 
 use rustc::plugin::Registry;
-use syntax::ast::{Expr, MetaItem, Mutability};
-use syntax::ext::base::{Annotatable, ExtCtxt, MultiDecorator};
+use syntax::ast::{Expr, Item, MetaItem, Mutability};
+use syntax::ext::base::{Annotatable, Decorator, ExtCtxt};
 use syntax::ext::build::AstBuilder;
 use syntax::ext::deriving::generic::{combine_substructure, EnumMatching, FieldInfo, MethodDef,
                                      Struct, Substructure, TraitDef, ty};
@@ -31,14 +31,16 @@ use syntax::parse::token::intern;
 use syntax::ptr::P;
 
 pub fn expand_derive_cc_trace(cx: &mut ExtCtxt,
-                              span: Span,
-                              mitem: &MetaItem,
-                              item: Annotatable,
-                              push: &mut FnMut(Annotatable))
+                              sp: Span,
+                              meta_item: &MetaItem,
+                              item: &Item,
+                              push: &mut FnMut(P<Item>))
 {
     println!("FITZGEN HELLO");
+    let ann = Annotatable::Item(P(item.clone()));
+
     let cc_trace_trait_def = TraitDef {
-        span: span,
+        span: sp,
         attributes: Vec::new(),
         path: ty::Path::new(vec!("bacon_rajan_cc", "Trace")),
         additional_bounds: Vec::new(),
@@ -61,20 +63,23 @@ pub fn expand_derive_cc_trace(cx: &mut ExtCtxt,
         associated_types: Vec::new(),
     };
 
-    cc_trace_trait_def.expand(cx, mitem, &item, push);
+    let mut push2 = |a: Annotatable| {
+        push(a.expect_item());
+    };
+    cc_trace_trait_def.expand(cx, meta_item, &ann, &mut push2);
 }
 
 fn cc_trace_substructure(cx: &mut ExtCtxt, trait_span: Span, substr: &Substructure) -> P<Expr> {
     let state_expr = match (substr.nonself_args.len(), substr.nonself_args.get(0)) {
         (1, Some(o_f)) => o_f,
-        _ => cx.span_bug(trait_span, "incorrect number of arguments in `derive(CcTrace)`")
+        _ => cx.span_bug(trait_span, "incorrect number of arguments in `derive_cc_trace`")
     };
 
     let call_cc_trace = |span, thing_expr| {
         let cc_trace_path = {
             let strs = vec!(
                 cx.ident_of("bacon_rajan_cc"),
-                cx.ident_of("CcTrace"),
+                cx.ident_of("Trace"),
                 cx.ident_of("trace"),
             );
 
@@ -88,7 +93,7 @@ fn cc_trace_substructure(cx: &mut ExtCtxt, trait_span: Span, substr: &Substructu
 
     let fields = match *substr.fields {
         Struct(ref fs) | EnumMatching(_, _, ref fs) => fs,
-        _ => cx.span_bug(trait_span, "impossible substructure in `jstraceable`")
+        _ => cx.span_bug(trait_span, "impossible substructure in `derice_cc_trace`")
     };
 
     for &FieldInfo { ref self_, span, .. } in fields.iter() {
@@ -100,5 +105,5 @@ fn cc_trace_substructure(cx: &mut ExtCtxt, trait_span: Span, substr: &Substructu
 
 #[plugin_registrar]
 pub fn plugin_registrar(reg: &mut Registry) {
-    reg.register_syntax_extension(intern("CcTrace"), MultiDecorator(Box::new(expand_derive_cc_trace)));
+    reg.register_syntax_extension(intern("derive_cc_trace"), Decorator(Box::new(expand_derive_cc_trace)));
 }
diff --git a/tests/simple_plugin_test.rs b/tests/simple_plugin_test.rs
index 6f36c20..db4d578 100644
--- a/tests/simple_plugin_test.rs
+++ b/tests/simple_plugin_test.rs
@@ -6,10 +6,12 @@ use bacon_rajan_cc::*;
 
 trace_macros!(true);
 
-#[derive(CcTrace, Debug)]
+#[derive(Debug)]
+#[derive_cc_trace]
 struct CycleCollectable {
     a: Cc<u32>,
     b: Cc<String>,
+    c: u32,
 }
 
 trace_macros!(false);
@@ -19,9 +21,10 @@ fn test_plugin() {
     let x = CycleCollectable {
         a: Cc::new(5),
         b: Cc::new("hello".into()),
+        c: 42
     };
 
-    CcTrace::trace(&x, &mut |v| {
+    Trace::trace(&x, &mut |v| {
         println!("traced {:?}", v);
     });