[DI] See through alloc_box borrows.

Author: nate-chandler

lib/SILOptimizer/Mandatory/DIMemoryUseCollector.cpp

@@ -51,7 +51,11 @@ static void gatherDestroysOfContainer(const DIMemoryObjectInfo &memoryInfo,
   // TODO: This should really be tracked separately from other destroys so that
   // we distinguish the lifetime of the container from the value itself.
   assert(isa<ProjectBoxInst>(uninitMemory));
-  auto *mui = cast<MarkUninitializedInst>(uninitMemory->getOperand(0));
+  auto value = uninitMemory->getOperand(0);
+  if (auto *bbi = dyn_cast<BeginBorrowInst>(value)) {
+    value = bbi->getOperand();
+  }
+  auto *mui = cast<MarkUninitializedInst>(value);
   for (auto *user : mui->getUsersOfType<DestroyValueInst>()) {
     useInfo.trackDestroy(user);
   }
@@ -114,6 +118,12 @@ DIMemoryObjectInfo::DIMemoryObjectInfo(MarkUninitializedInst *MI)
   auto &Module = MI->getModule();
 
   SILValue Address = MemoryInst;
+  if (auto BBI = MemoryInst->getSingleUserOfType<BeginBorrowInst>()) {
+    if (auto PBI = BBI->getSingleUserOfType<ProjectBoxInst>()) {
+      IsBox = true;
+      Address = PBI;
+    }
+  }
   if (auto PBI = MemoryInst->getSingleUserOfType<ProjectBoxInst>()) {
     IsBox = true;
     Address = PBI;

lib/SILOptimizer/Mandatory/DIMemoryUseCollector.h

@@ -102,10 +102,14 @@ class DIMemoryObjectInfo {
   /// with the memory info.
   SingleValueInstruction *getUninitializedValue() const {
     if (IsBox) {
+      SILValue inst = MemoryInst;
+      if (auto *bbi = MemoryInst->getSingleUserOfType<BeginBorrowInst>()) {
+        inst = bbi;
+      }
       // TODO: consider just storing the ProjectBoxInst in this case.
-      auto *pbi = MemoryInst->getSingleUserOfType<ProjectBoxInst>();
-      assert(pbi);
-      return pbi;
+      SingleValueInstruction *svi = inst->getSingleUserOfType<ProjectBoxInst>();
+      assert(svi);
+      return svi;
     }
     return MemoryInst;
   }

lib/SILOptimizer/Mandatory/DiagnoseInvalidEscapingCaptures.cpp

@@ -157,7 +157,11 @@ const ParamDecl *getParamDeclFromOperand(SILValue value) {
 
 bool isUseOfSelfInInitializer(Operand *oper) {
   if (auto *PBI = dyn_cast<ProjectBoxInst>(oper->get())) {
-    if (auto *MUI = dyn_cast<MarkUninitializedInst>(PBI->getOperand())) {
+    SILValue value = PBI->getOperand();
+    if (auto *bbi = dyn_cast<BeginBorrowInst>(value)) {
+      value = bbi->getOperand();
+    }
+    if (auto *MUI = dyn_cast<MarkUninitializedInst>(value)) {
       switch (MUI->getMarkUninitializedKind()) {
       case MarkUninitializedInst::Kind::Var:
         return false;