From 71df8e655c1a7a435082de753694821f359fb8a9 Mon Sep 17 00:00:00 2001
From: Luqman Aden <me@luqman.ca>
Date: Mon, 4 Aug 2014 18:58:48 -0700
Subject: [PATCH] librustc: Encode upvar_borrow_map in metadata.

---
 src/librustc/metadata/common.rs  |  3 ++-
 src/librustc/middle/astencode.rs | 43 +++++++++++++++++++++++++++++++-
 src/librustc/middle/freevars.rs  |  8 +++---
 src/librustc/middle/ty.rs        |  4 +--
 4 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/src/librustc/metadata/common.rs b/src/librustc/metadata/common.rs
index a42880b2d36c..8ed471ec58a5 100644
--- a/src/librustc/metadata/common.rs
+++ b/src/librustc/metadata/common.rs
@@ -140,9 +140,10 @@ pub enum astencode_tag { // Reserves 0x40 -- 0x5f
     tag_table_moves_map = 0x52,
     tag_table_capture_map = 0x53,
     tag_table_unboxed_closure_type = 0x54,
+    tag_table_upvar_borrow_map = 0x55,
 }
 static first_astencode_tag: uint = tag_ast as uint;
-static last_astencode_tag: uint = tag_table_unboxed_closure_type as uint;
+static last_astencode_tag: uint = tag_table_upvar_borrow_map as uint;
 impl astencode_tag {
     pub fn from_uint(value : uint) -> Option<astencode_tag> {
         let is_a_tag = first_astencode_tag <= value && value <= last_astencode_tag;
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index f68501bbb914..33b663dea155 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -18,6 +18,7 @@ use driver::session::Session;
 use metadata::decoder;
 use middle::def;
 use e = metadata::encoder;
+use middle::freevars;
 use middle::freevars::freevar_entry;
 use middle::region;
 use metadata::tydecode;
@@ -551,6 +552,15 @@ impl tr for freevar_entry {
     }
 }
 
+impl tr for ty::UpvarBorrow {
+    fn tr(&self, xcx: &ExtendedDecodeContext) -> ty::UpvarBorrow {
+        ty::UpvarBorrow {
+            kind: self.kind,
+            region: self.region.tr(xcx)
+        }
+    }
+}
+
 // ______________________________________________________________________
 // Encoding and decoding of MethodCallee
 
@@ -1061,7 +1071,29 @@ fn encode_side_tables_for_id(ecx: &e::EncodeContext,
                     Ok(encode_freevar_entry(rbml_w, fv_entry))
                 });
             })
-        })
+        });
+
+        for freevar in fv.iter() {
+            match freevars::get_capture_mode(tcx, id) {
+                freevars::CaptureByRef => {
+                    rbml_w.tag(c::tag_table_upvar_borrow_map, |rbml_w| {
+                        rbml_w.id(id);
+                        rbml_w.tag(c::tag_table_val, |rbml_w| {
+                            let var_id = freevar.def.def_id().node;
+                            let upvar_id = ty::UpvarId {
+                                var_id: var_id,
+                                closure_expr_id: id
+                            };
+                            let upvar_borrow = tcx.upvar_borrow_map.borrow()
+                                                  .get_copy(&upvar_id);
+                            var_id.encode(rbml_w);
+                            upvar_borrow.encode(rbml_w);
+                        })
+                    })
+                }
+                _ => {}
+            }
+        }
     }
 
     let lid = ast::DefId { krate: ast::LOCAL_CRATE, node: id };
@@ -1468,6 +1500,15 @@ fn decode_side_tables(xcx: &ExtendedDecodeContext,
                         }).unwrap().move_iter().collect();
                         dcx.tcx.freevars.borrow_mut().insert(id, fv_info);
                     }
+                    c::tag_table_upvar_borrow_map => {
+                        let var_id: ast::NodeId = Decodable::decode(val_dsr).unwrap();
+                        let upvar_id = ty::UpvarId {
+                            var_id: xcx.tr_id(var_id),
+                            closure_expr_id: id
+                        };
+                        let ub: ty::UpvarBorrow = Decodable::decode(val_dsr).unwrap();
+                        dcx.tcx.upvar_borrow_map.borrow_mut().insert(upvar_id, ub.tr(xcx));
+                    }
                     c::tag_table_tcache => {
                         let pty = val_dsr.read_polytype(xcx);
                         let lid = ast::DefId { krate: ast::LOCAL_CRATE, node: id };
diff --git a/src/librustc/middle/freevars.rs b/src/librustc/middle/freevars.rs
index f6887718ec13..eda567f7d187 100644
--- a/src/librustc/middle/freevars.rs
+++ b/src/librustc/middle/freevars.rs
@@ -14,6 +14,7 @@
 #![allow(non_camel_case_types)]
 
 use middle::def;
+use middle::mem_categorization::Typer;
 use middle::resolve;
 use middle::ty;
 use util::nodemap::{DefIdSet, NodeMap, NodeSet};
@@ -147,11 +148,8 @@ pub fn with_freevars<T>(tcx: &ty::ctxt, fid: ast::NodeId, f: |&[freevar_entry]|
     }
 }
 
-pub fn get_capture_mode(tcx: &ty::ctxt,
-                        closure_expr_id: ast::NodeId)
-                        -> CaptureMode
-{
-    let fn_ty = ty::node_id_to_type(tcx, closure_expr_id);
+pub fn get_capture_mode<T: Typer>(tcx: &T, closure_expr_id: ast::NodeId) -> CaptureMode {
+    let fn_ty = tcx.node_ty(closure_expr_id).ok().expect("couldn't find closure ty?");
     match ty::ty_closure_store(fn_ty) {
         ty::RegionTraitStore(..) => CaptureByRef,
         ty::UniqTraitStore => CaptureByValue
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 0cc5486013aa..a4588da1bd7d 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -539,7 +539,7 @@ pub struct UpvarId {
     pub closure_expr_id: ast::NodeId,
 }
 
-#[deriving(Clone, PartialEq, Eq, Hash, Show)]
+#[deriving(Clone, PartialEq, Eq, Hash, Show, Encodable, Decodable)]
 pub enum BorrowKind {
     /// Data must be immutable and is aliasable.
     ImmBorrow,
@@ -634,7 +634,7 @@ pub enum BorrowKind {
  *   the closure, so sometimes it is necessary for them to be larger
  *   than the closure lifetime itself.
  */
-#[deriving(PartialEq, Clone)]
+#[deriving(PartialEq, Clone, Encodable, Decodable)]
 pub struct UpvarBorrow {
     pub kind: BorrowKind,
     pub region: ty::Region,