From 4028ac245a8556353b5ba27ffe1c8f3d8f17fe03 Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Wed, 29 Jan 2020 11:15:53 -0800
Subject: [PATCH] EscapeAnalysis: add support for access markers.

This will be critical when OSSA relies on access markers everywhere
and more passes are converted to OSSA.
---
 lib/SILOptimizer/Analysis/EscapeAnalysis.cpp |  1 +
 test/SILOptimizer/escape_analysis.sil        | 22 ++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp b/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp
index 62e0059646990..e5b1eec09a578 100644
--- a/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp
+++ b/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp
@@ -122,6 +122,7 @@ SILValue EscapeAnalysis::getPointerBase(SILValue value) {
   case ValueKind::StructElementAddrInst:
   case ValueKind::StructExtractInst:
   case ValueKind::TupleElementAddrInst:
+  case ValueKind::BeginAccessInst:
   case ValueKind::UncheckedTakeEnumDataAddrInst:
   case ValueKind::UncheckedEnumDataInst:
   case ValueKind::MarkDependenceInst:
diff --git a/test/SILOptimizer/escape_analysis.sil b/test/SILOptimizer/escape_analysis.sil
index eddfac11b7f09..e510fbadcda74 100644
--- a/test/SILOptimizer/escape_analysis.sil
+++ b/test/SILOptimizer/escape_analysis.sil
@@ -1888,3 +1888,25 @@ bb0(%0 : @guaranteed $@sil_unowned Builtin.NativeObject):
   %1 = strong_copy_unowned_value %0 : $@sil_unowned Builtin.NativeObject
   return %1 : $Builtin.NativeObject
 }
+
+// Test begin_access. It should look like a derived pointer.
+// CHECK-LABEL: CG of testAccessMarkerHelper
+sil hidden @testAccessMarkerHelper : $@convention(thin) (@inout SomeData) -> () {
+bb0(%0 : $*SomeData):
+  %1 = tuple ()
+  return %1 : $()
+}
+
+// CHECK-LABEL: CG of testAccessMarker
+// CHECK-NEXT:   Arg %0 Esc: A, Succ: (%0.1)
+// CHECK-NEXT:   Con [ref] %0.1 Esc: G, Succ:
+// CHECK-LABEL: End
+sil hidden @testAccessMarker : $@convention(thin) (@inout SomeData) -> () {
+bb0(%0 : $*SomeData):
+  %1 = begin_access [modify] [static] %0 : $*SomeData
+  %2 = function_ref @testAccessMarkerHelper : $@convention(thin) (@inout SomeData) -> ()
+  %3 = apply %2(%1) : $@convention(thin) (@inout SomeData) -> ()
+  end_access %1 : $*SomeData
+  %5 = tuple ()
+  return %5 : $()
+}