From 368b12e7cdf563f9b94fb86d33666e8bd0b88a06 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <jolesen@mozilla.com>
Date: Wed, 19 Oct 2016 18:27:22 -0700
Subject: [PATCH] Use more precise lifetimes for Builder.

Distinguish the lifetime of the Cursor and its referenced function
layout.

Use two separate function lifetimes: 'fc and 'fd. The borrow checker
seems to get confused if we don't.
---
 lib/cretonne/src/ir/builder.rs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/cretonne/src/ir/builder.rs b/lib/cretonne/src/ir/builder.rs
index e8646d0dd1..a360263138 100644
--- a/lib/cretonne/src/ir/builder.rs
+++ b/lib/cretonne/src/ir/builder.rs
@@ -49,15 +49,15 @@ impl<T: InstBuilderBase> InstBuilder for T {}
 ///
 /// A `Builder` holds mutable references to a data flow graph and a layout cursor. It provides
 /// convenience method for creating and inserting instructions at the current cursor position.
-pub struct Builder<'a> {
-    pub dfg: &'a mut DataFlowGraph,
-    pub pos: &'a mut Cursor<'a>,
+pub struct Builder<'c, 'fc: 'c, 'fd> {
+    pub pos: &'c mut Cursor<'fc>,
+    pub dfg: &'fd mut DataFlowGraph,
 }
 
-impl<'a> Builder<'a> {
+impl<'c, 'fc, 'fd> Builder<'c, 'fc, 'fd> {
     /// Create a new builder which inserts instructions at `pos`.
     /// The `dfg` and `pos.layout` references should be from the same `Function`.
-    pub fn new(dfg: &'a mut DataFlowGraph, pos: &'a mut Cursor<'a>) -> Builder<'a> {
+    pub fn new(dfg: &'fd mut DataFlowGraph, pos: &'c mut Cursor<'fc>) -> Builder<'c, 'fc, 'fd> {
         Builder {
             dfg: dfg,
             pos: pos,
@@ -78,7 +78,7 @@ impl<'a> Builder<'a> {
     }
 }
 
-impl<'a> InstBuilderBase for Builder<'a> {
+impl<'c, 'fc, 'fd> InstBuilderBase for Builder<'c, 'fc, 'fd> {
     fn data_flow_graph(&self) -> &DataFlowGraph {
         self.dfg
     }