From c881a4f0088c98fb99565ae472ee315ddda731af Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Sun, 26 Jan 2020 22:32:26 -0800
Subject: [PATCH] Fix EscapeAnalysis verification for an array.uninitialized
 case.

The most recently added verification exposed an issue where the code
pattern-matches an array.uninitialized call. The pattern matching does
not handle multiple tuple_extracts but the API returned "success" in
some of those cases.

Fixes the verifier assert when building ImagePicker.
---
 lib/SILOptimizer/Analysis/EscapeAnalysis.cpp  |  7 ++--
 test/SILOptimizer/escape_analysis_reduced.sil | 33 +++++++++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp b/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp
index dbfa9931c9cb1..62e0059646990 100644
--- a/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp
+++ b/lib/SILOptimizer/Analysis/EscapeAnalysis.cpp
@@ -1822,13 +1822,16 @@ EscapeAnalysis::canOptimizeArrayUninitializedCall(
 
   // Check if the result is used in the usual way: extracting the
   // array and the element pointer with tuple_extract.
+  //
+  // Do not ignore any uses, even redundant tuple_extract, because all apply
+  // uses must be mapped to ConnectionGraph nodes by the client of this API.
   for (Operand *use : getNonDebugUses(ai)) {
     if (auto *tei = dyn_cast<TupleExtractInst>(use->getUser())) {
-      if (tei->getFieldNo() == 0) {
+      if (tei->getFieldNo() == 0 && !call.arrayStruct) {
         call.arrayStruct = tei;
         continue;
       }
-      if (tei->getFieldNo() == 1) {
+      if (tei->getFieldNo() == 1 && !call.arrayElementPtr) {
         call.arrayElementPtr = tei;
         continue;
       }
diff --git a/test/SILOptimizer/escape_analysis_reduced.sil b/test/SILOptimizer/escape_analysis_reduced.sil
index c9a31037bbc24..352f4a160bbb4 100644
--- a/test/SILOptimizer/escape_analysis_reduced.sil
+++ b/test/SILOptimizer/escape_analysis_reduced.sil
@@ -559,3 +559,36 @@ bb65(%614 : $Error):
 bb72(%681 : $Error):
   throw %681 : $Error
 }
+
+//=============================================================================
+// Test an "array.uninitialized" with multiple tuple_extract's but no
+// other unusual uses. Make sure canOptimizeArrayUninitializedCall
+// returns false; otherwise graph verification can fail because only
+// one of the tuple_extracts is mapped to a node.
+
+// specialized static Array._adoptStorage(_:count:)
+sil [_semantics "array.uninitialized"] @$sSa13_adoptStorage_5countSayxG_SpyxGts016_ContiguousArrayB0CyxGn_SitFZSo5Int64V_Tg5 : $@convention(method) (@owned _ContiguousArrayStorage<Int64>, Int, @thin Array<Int64>.Type) -> (@owned Array<Int64>, UnsafeMutablePointer<Int64>)
+
+// CHECK-LABEL: CG of testArrayUninitResultMapping
+// CHECK-NEXT:   [ref] %0 Esc: , Succ: (%0.1)
+// CHECK-NEXT:   Con [int] %0.1 Esc: G, Succ: (%0.2)
+// CHECK-NEXT:   Con [ref] %0.2 Esc: G, Succ:
+// CHECK-NEXT:   Val %2 Esc: , Succ: (%2.1)
+// CHECK-NEXT:   Con %2.1 Esc: G, Succ:
+// CHECK-LABEL: End
+sil hidden @testArrayUninitResultMapping : $@convention(thin) () -> () {
+bb0:
+  %0 = alloc_ref [tail_elems $Int64 * undef : $Builtin.Word] $_ContiguousArrayStorage<Int64>
+  // function_ref specialized static Array._adoptStorage(_:count:)
+  %1 = function_ref @$sSa13_adoptStorage_5countSayxG_SpyxGts016_ContiguousArrayB0CyxGn_SitFZSo5Int64V_Tg5 : $@convention(method) (@owned _ContiguousArrayStorage<Int64>, Int, @thin Array<Int64>.Type) -> (@owned Array<Int64>, UnsafeMutablePointer<Int64>)
+  %2 = apply %1(%0, undef, undef) : $@convention(method) (@owned _ContiguousArrayStorage<Int64>, Int, @thin Array<Int64>.Type) -> (@owned Array<Int64>, UnsafeMutablePointer<Int64>)
+  %3 = tuple_extract %2 : $(Array<Int64>, UnsafeMutablePointer<Int64>), 0
+  %4 = tuple_extract %2 : $(Array<Int64>, UnsafeMutablePointer<Int64>), 1
+  %5 = tuple_extract %2 : $(Array<Int64>, UnsafeMutablePointer<Int64>), 0
+  %6 = struct_extract %5 : $Array<Int64>, #Array._buffer
+  %7 = struct_extract %6 : $_ArrayBuffer<Int64>, #_ArrayBuffer._storage
+  %8 = struct_extract %7 : $_BridgeStorage<__ContiguousArrayStorageBase>, #_BridgeStorage.rawValue
+  strong_retain %8 : $Builtin.BridgeObject
+  %10 = tuple ()
+  return %10 : $()
+}