Merge pull request #60604 from jckarter/silbuilder-dont-delete-operands-in-peepholes

SIL: Don't eagerly erase instructions in builder peepholes.

Author: jckarter

lib/SIL/IR/SILBuilder.cpp

@@ -480,16 +480,12 @@ SILBuilder::emitDestroyValue(SILLocation Loc, SILValue Operand) {
 
 SILValue SILBuilder::emitThickToObjCMetatype(SILLocation Loc, SILValue Op,
                                              SILType Ty) {
-  // If the operand is an otherwise-unused 'metatype' instruction in the
-  // same basic block, zap it and create a 'metatype' instruction that
-  // directly produces an Objective-C metatype.
+  // If the operand is a 'metatype' instruction accessing a known static type's
+  // metadata, create a 'metatype' instruction that
+  // directly produces the Objective-C class object representation instead.
   if (auto metatypeInst = dyn_cast<MetatypeInst>(Op)) {
-    if (metatypeInst->use_empty() &&
-        metatypeInst->getParent() == getInsertionBB()) {
-      auto origLoc = metatypeInst->getLoc();
-      metatypeInst->eraseFromParent();
-      return createMetatype(origLoc, Ty);
-    }
+    auto origLoc = metatypeInst->getLoc();
+    return createMetatype(origLoc, Ty);
   }
 
   // Just create the thick_to_objc_metatype instruction.
@@ -498,16 +494,12 @@ SILValue SILBuilder::emitThickToObjCMetatype(SILLocation Loc, SILValue Op,
 
 SILValue SILBuilder::emitObjCToThickMetatype(SILLocation Loc, SILValue Op,
                                              SILType Ty) {
-  // If the operand is an otherwise-unused 'metatype' instruction in the
-  // same basic block, zap it and create a 'metatype' instruction that
-  // directly produces a thick metatype.
+  // If the operand is a 'metatype' instruction accessing a known static type's
+  // metadata, create a 'metatype' instruction that directly produces the
+  // Swift metatype representation instead.
   if (auto metatypeInst = dyn_cast<MetatypeInst>(Op)) {
-    if (metatypeInst->use_empty() &&
-        metatypeInst->getParent() == getInsertionBB()) {
-      auto origLoc = metatypeInst->getLoc();
-      metatypeInst->eraseFromParent();
-      return createMetatype(origLoc, Ty);
-    }
+    auto origLoc = metatypeInst->getLoc();
+    return createMetatype(origLoc, Ty);
   }
 
   // Just create the objc_to_thick_metatype instruction.

test/SILGen/use_thick_metatype_after_objc.swift

@@ -0,0 +1,23 @@
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-silgen -enable-implicit-dynamic -verify %s
+// rdar://98418860
+
+// REQUIRES: objc_interop
+
+import Foundation
+
+@propertyWrapper
+struct ExamplePropertyWrapper {
+    var wrappedValue: Bool = false
+}
+
+@objcMembers
+class ExampleClass {
+    @ExamplePropertyWrapper
+    static var exampleProperty: Bool
+}
+
+class ExampleCallingClass {
+    func exampleSegfaultingCall() {
+        ExampleClass.exampleProperty.toggle()
+    }
+}