Merge pull request #16564 from dcci/42-shadow

Author: swift-ci

lib/IRGen/IRGenSIL.cpp

@@ -719,6 +719,32 @@ class IRGenSILFunction :
     }
   }
 
+  /// To make it unambiguous whether a `var` binding has been initialized,
+  /// zero-initialize the first pointer-sized field. LLDB uses this to
+  /// recognize to detect uninitizialized variables. This can be removed once
+  /// swiftc switches to @llvm.dbg.addr() intrinsics.
+  void zeroInit(llvm::AllocaInst *AI) {
+    if (!AI)
+      return;
+
+    // Only do this at -Onone.
+    if (IGM.IRGen.Opts.shouldOptimize())
+      return;
+
+    auto &DL = IGM.DataLayout;
+    if (DL.getTypeSizeInBits(AI->getAllocatedType()) <
+        DL.getPointerSizeInBits())
+      return;
+
+    llvm::IRBuilder<> ZeroInitBuilder(AI->getNextNode());
+    ZeroInitBuilder.SetCurrentDebugLocation(nullptr);
+    auto *BC =
+        ZeroInitBuilder.CreateBitCast(AI, IGM.OpaquePtrTy->getPointerTo());
+    ZeroInitBuilder.CreateAlignedStore(
+        llvm::ConstantPointerNull::get(IGM.OpaquePtrTy), BC,
+        IGM.getPointerAlignment().getValue());
+  }
+
   /// Account for bugs in LLVM.
   ///
   /// - The LLVM type legalizer currently doesn't update debug
@@ -742,6 +768,7 @@ class IRGenSILFunction :
     auto &Alloca = ShadowStackSlots[{ArgNo, {Scope, Name}}];
     if (!Alloca.isValid())
       Alloca = createAlloca(Storage->getType(), Align, Name+".addr");
+    zeroInit(dyn_cast<llvm::AllocaInst>(Alloca.getAddress()));
 
     ArtificialLocation AutoRestore(Scope, IGM.DebugInfo, Builder);
     Builder.CreateStore(Storage, Alloca.getAddress(), Align);
@@ -4000,31 +4027,10 @@ void IRGenSILFunction::visitAllocStackInst(swift::AllocStackInst *i) {
   if (!Decl)
     return;
 
-  // To make it unambiguous whether a `var` binding has been initialized,
-  // zero-initialize the first pointer-sized field. LLDB uses this to
-  // recognize to detect uninitizialized variables. This can be removed once
-  // swiftc switches to @llvm.dbg.addr() intrinsics.
-  auto zeroInit = [&]() {
-    if (IGM.IRGen.Opts.shouldOptimize())
-      return;
-    Type Desugared = Decl->getType()->getDesugaredType();
-    if (!Desugared->getClassOrBoundGenericClass() &&
-        !Desugared->getStructOrBoundGenericStruct())
-      return;
-
-    auto *AI = dyn_cast<llvm::AllocaInst>(addr.getAddress().getAddress());
-    if (!AI)
-      return;
-
-    auto &DL = IGM.DataLayout;
-    if (DL.getTypeSizeInBits(AI->getAllocatedType()) < DL.getPointerSizeInBits())
-      return;
-
-    auto *BC = Builder.CreateBitCast(AI, IGM.OpaquePtrTy->getPointerTo());
-    Builder.CreateStore(llvm::ConstantPointerNull::get(IGM.OpaquePtrTy), BC,
-                        IGM.getPointerAlignment());
-  };
-  zeroInit();
+  Type Desugared = Decl->getType()->getDesugaredType();
+  if (Desugared->getClassOrBoundGenericClass() ||
+      Desugared->getStructOrBoundGenericStruct())
+    zeroInit(dyn_cast<llvm::AllocaInst>(addr.getAddress().getAddress()));
   emitDebugInfoForAllocStack(i, type, addr.getAddress().getAddress());
 }
 

test/DebugInfo/returnlocation.swift

@@ -12,8 +12,7 @@ import Foundation
 // CHECK_NONE: define{{( protected)?}} {{.*}}void {{.*}}none
 public func none(_ a: inout Int64) {
   // CHECK_NONE: call void @llvm.dbg{{.*}}, !dbg
-  // CHECK_NONE: store{{.*}}, !dbg
-  // CHECK_NONE: !dbg ![[NONE_INIT:.*]]
+  // CHECK_NONE: store i64{{.*}}, !dbg ![[NONE_INIT:.*]]
   a -= 2
   // CHECK_NONE: ret {{.*}}, !dbg ![[NONE_RET:.*]]
   // CHECK_NONE: ![[NONE_INIT]] = !DILocation(line: [[@LINE-2]], column:

test/DebugInfo/shadowcopy-linetable.swift

@@ -8,6 +8,8 @@ func foo(_ x: inout Int64) {
   // not.
   // CHECK: %[[X:.*]] = alloca %Ts5Int64V*, align {{(4|8)}}
   // CHECK-NEXT: call void @llvm.dbg.declare
+  // CHECK-NEXT: [[ZEROED:%[0-9]+]] = bitcast %Ts5Int64V** %[[X]] to %swift.opaque**
+  // CHECK-NEXT: store %swift.opaque* null, %swift.opaque** [[ZEROED]], align {{(4|8)}}
   // CHECK: store %Ts5Int64V* %0, %Ts5Int64V** %[[X]], align {{(4|8)}}
   // CHECK-SAME: !dbg ![[LOC0:.*]]
   // CHECK-NEXT: getelementptr inbounds %Ts5Int64V, %Ts5Int64V* %0, i32 0, i32 0,

test/DebugInfo/uninitialized.swift

@@ -8,8 +8,8 @@ public func f() {
   var object: MyClass
   // CHECK: %[[OBJ:.*]] = alloca %[[T1:.*]]*, align
   // CHECK: call void @llvm.dbg.declare(metadata %[[T1]]** %[[OBJ]],
-  // CHECK: %[[BC1:.*]] = bitcast %[[T1]]** %[[OBJ]] to %swift.opaque**, !dbg
-  // CHECK: store %swift.opaque* null, %swift.opaque** %[[BC1]], align {{.*}}, !dbg
+  // CHECK: %[[BC1:.*]] = bitcast %[[T1]]** %[[OBJ]] to %swift.opaque**
+  // CHECK: store %swift.opaque* null, %swift.opaque** %[[BC1]], align {{.*}}
   // OPT-NOT: store
   // OPT: ret
 }
@@ -20,8 +20,8 @@ public func g() {
   var dict: Dictionary<Int64, Int64>
   // CHECK: %[[DICT:.*]] = alloca %[[T2:.*]], align
   // CHECK: call void @llvm.dbg.declare(metadata %[[T2]]* %[[DICT]],
-  // CHECK: %[[BC2:.*]] = bitcast %[[T2]]* %[[DICT]] to %swift.opaque**, !dbg
-  // CHECK: store %swift.opaque* null, %swift.opaque** %[[BC2]], align {{.*}}, !dbg
+  // CHECK: %[[BC2:.*]] = bitcast %[[T2]]* %[[DICT]] to %swift.opaque**
+  // CHECK: store %swift.opaque* null, %swift.opaque** %[[BC2]], align {{.*}}
   // OPT-NOT: store
   // OPT: ret
 }