From d16a213c1d52370845337e5c62eb6e60dd709b77 Mon Sep 17 00:00:00 2001
From: Erik Eckstein <eeckstein@apple.com>
Date: Thu, 5 Dec 2024 07:20:46 +0100
Subject: [PATCH] SILVerifier: fix a wrong check for witness_method
 instructions

Consider that the lookup-type can be an opaque return type.

Also fixing the SILPrinter.

Fixes a verifier crash
https://github.com/swiftlang/swift/issues/77955
140939536
---
 lib/SIL/IR/SILPrinter.cpp                     |  5 +--
 lib/SIL/Verifier/SILVerifier.cpp              |  2 +-
 .../propagate_opaque_return_type.swift        | 33 +++++++++++++++++++
 3 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 test/SILOptimizer/propagate_opaque_return_type.swift

diff --git a/lib/SIL/IR/SILPrinter.cpp b/lib/SIL/IR/SILPrinter.cpp
index 7112ac3fd3a16..5d7b5b8924d01 100644
--- a/lib/SIL/IR/SILPrinter.cpp
+++ b/lib/SIL/IR/SILPrinter.cpp
@@ -2520,10 +2520,11 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
     PrintOptions QualifiedSILTypeOptions =
         PrintOptions::printQualifiedSILType();
     QualifiedSILTypeOptions.CurrentModule = WMI->getModule().getSwiftModule();
-    *this << "$" << WMI->getLookupType() << ", " << WMI->getMember() << " : ";
+    auto lookupType = WMI->getLookupType();
+    *this << "$" << lookupType << ", " << WMI->getMember() << " : ";
     WMI->getMember().getDecl()->getInterfaceType().print(
         PrintState.OS, QualifiedSILTypeOptions);
-    if (!WMI->getTypeDependentOperands().empty()) {
+    if ((getLocalArchetypeOf(lookupType) || lookupType->hasDynamicSelfType()) && !WMI->getTypeDependentOperands().empty()) {
       *this << ", ";
       *this << getIDAndForcedPrintedType(WMI->getTypeDependentOperands()[0].get());
     }
diff --git a/lib/SIL/Verifier/SILVerifier.cpp b/lib/SIL/Verifier/SILVerifier.cpp
index ed59536c73137..eba86e73bd6d2 100644
--- a/lib/SIL/Verifier/SILVerifier.cpp
+++ b/lib/SIL/Verifier/SILVerifier.cpp
@@ -4177,7 +4177,7 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
               "Must have a type dependent operand for the opened archetype");
       verifyLocalArchetype(AMI, lookupType);
     } else {
-      require(AMI->getTypeDependentOperands().empty(),
+      require(AMI->getTypeDependentOperands().empty() || lookupType->hasLocalArchetype(),
               "Should not have an operand for the opened existential");
     }
     if (!isa<ArchetypeType>(lookupType) && !isa<DynamicSelfType>(lookupType)) {
diff --git a/test/SILOptimizer/propagate_opaque_return_type.swift b/test/SILOptimizer/propagate_opaque_return_type.swift
new file mode 100644
index 0000000000000..75ba610f8f228
--- /dev/null
+++ b/test/SILOptimizer/propagate_opaque_return_type.swift
@@ -0,0 +1,33 @@
+// RUN: %target-run-simple-swift(-O -Xfrontend -sil-verify-all) | %FileCheck %s
+
+protocol P {}
+extension P {
+  func foo() -> some Sequence<Int> {
+    [1, 2, 3]
+  }
+}
+
+struct B {
+  let p: P
+
+  @inline(never)
+  func bar() {
+    for x in p.foo() {
+      print(x)
+    }
+  }
+}
+
+
+struct S : P {
+  var x = 0
+}
+
+
+let b = B(p: S())
+
+// CHECK:      1
+// CHECK-NEXT: 2
+// CHECK-NEXT: 3
+b.bar()
+