From 8ebc1c9fd88640b1833e0743b649a957f3337720 Mon Sep 17 00:00:00 2001
From: Luqman Aden <laden@csclub.uwaterloo.ca>
Date: Fri, 5 Dec 2014 18:35:16 -0500
Subject: [PATCH] librustc: Fix debuginfo for captured variables in non-FnOnce
 unboxed closures.

---
 src/librustc_trans/trans/closure.rs           |  4 +-
 src/librustc_trans/trans/debuginfo.rs         |  6 ++-
 .../var-captured-in-stack-closure.rs          | 47 +++++++++++++++++--
 3 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/src/librustc_trans/trans/closure.rs b/src/librustc_trans/trans/closure.rs
index bb4df00bd94..106c272a779 100644
--- a/src/librustc_trans/trans/closure.rs
+++ b/src/librustc_trans/trans/closure.rs
@@ -286,7 +286,6 @@ fn load_environment<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
             debuginfo::create_captured_var_metadata(
                 bcx,
                 def_id.node,
-                cdata_ty,
                 env_pointer_alloca,
                 i,
                 captured_by_ref,
@@ -326,7 +325,7 @@ fn load_unboxed_closure_environment<'blk, 'tcx>(
     // Store the pointer to closure data in an alloca for debug info because that's what the
     // llvm.dbg.declare intrinsic expects
     let env_pointer_alloca = if bcx.sess().opts.debuginfo == FullDebugInfo {
-        let alloc = alloc_ty(bcx, ty::mk_mut_ptr(bcx.tcx(), self_type), "__debuginfo_env_ptr");
+        let alloc = alloca(bcx, val_ty(llenv), "__debuginfo_env_ptr");
         Store(bcx, llenv, alloc);
         Some(alloc)
     } else {
@@ -355,7 +354,6 @@ fn load_unboxed_closure_environment<'blk, 'tcx>(
             debuginfo::create_captured_var_metadata(
                 bcx,
                 def_id.node,
-                self_type,
                 env_pointer_alloca,
                 i,
                 captured_by_ref,
diff --git a/src/librustc_trans/trans/debuginfo.rs b/src/librustc_trans/trans/debuginfo.rs
index 555cb000489..09cfbde43e5 100644
--- a/src/librustc_trans/trans/debuginfo.rs
+++ b/src/librustc_trans/trans/debuginfo.rs
@@ -882,7 +882,6 @@ pub fn create_local_var_metadata(bcx: Block, local: &ast::Local) {
 /// Adds the created metadata nodes directly to the crate's IR.
 pub fn create_captured_var_metadata<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
                                                 node_id: ast::NodeId,
-                                                env_data_type: Ty<'tcx>,
                                                 env_pointer: ValueRef,
                                                 env_index: uint,
                                                 captured_by_ref: bool,
@@ -928,7 +927,10 @@ pub fn create_captured_var_metadata<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
     let variable_type = node_id_type(bcx, node_id);
     let scope_metadata = bcx.fcx.debug_context.get_ref(cx, span).fn_metadata;
 
-    let llvm_env_data_type = type_of::type_of(cx, env_data_type);
+    // env_pointer is the alloca containing the pointer to the environment,
+    // so it's type is **EnvironmentType. In order to find out the type of
+    // the environment we have to "dereference" two times.
+    let llvm_env_data_type = val_ty(env_pointer).element_type().element_type();
     let byte_offset_of_var_in_env = machine::llelement_offset(cx,
                                                               llvm_env_data_type,
                                                               env_index);
diff --git a/src/test/debuginfo/var-captured-in-stack-closure.rs b/src/test/debuginfo/var-captured-in-stack-closure.rs
index 92a3d358f5c..761d0f0be8f 100644
--- a/src/test/debuginfo/var-captured-in-stack-closure.rs
+++ b/src/test/debuginfo/var-captured-in-stack-closure.rs
@@ -28,6 +28,19 @@
 // gdb-command:print *owned
 // gdb-check:$5 = 6
 
+// gdb-command:continue
+
+// gdb-command:print variable
+// gdb-check:$6 = 2
+// gdb-command:print constant
+// gdb-check:$7 = 2
+// gdb-command:print a_struct
+// gdb-check:$8 = {a = -3, b = 4.5, c = 5}
+// gdb-command:print *struct_ref
+// gdb-check:$9 = {a = -3, b = 4.5, c = 5}
+// gdb-command:print *owned
+// gdb-check:$10 = 6
+
 
 // === LLDB TESTS ==================================================================================
 
@@ -44,6 +57,20 @@
 // lldb-command:print *owned
 // lldb-check:[...]$4 = 6
 
+// lldb-command:continue
+
+// lldb-command:print variable
+// lldb-check:[...]$5 = 2
+// lldb-command:print constant
+// lldb-check:[...]$6 = 2
+// lldb-command:print a_struct
+// lldb-check:[...]$7 = Struct { a: -3, b: 4.5, c: 5 }
+// lldb-command:print *struct_ref
+// lldb-check:[...]$8 = Struct { a: -3, b: 4.5, c: 5 }
+// lldb-command:print *owned
+// lldb-check:[...]$9 = 6
+
+#![feature(unboxed_closures)]
 #![allow(unused_variables)]
 
 struct Struct {
@@ -65,12 +92,22 @@ fn main() {
     let struct_ref = &a_struct;
     let owned = box 6;
 
-    let closure = || {
-        zzz(); // #break
-        variable = constant + a_struct.a + struct_ref.a + *owned;
-    };
+    {
+        let closure = || {
+            zzz(); // #break
+            variable = constant + a_struct.a + struct_ref.a + *owned;
+        };
 
-    closure();
+        closure();
+    }
+
+    {
+        let mut unboxed_closure = |&mut:| {
+            zzz(); // #break
+            variable = constant + a_struct.a + struct_ref.a + *owned;
+        };
+        unboxed_closure();
+    }
 }
 
 fn zzz() {()}