IRGen: Fix keypath pattern emission regression in multi-threaded mode

We were emitting relative references to entities that might be in
another translation unit. Use a GOT entry or thunk where appropriate.

Fixes <rdar://problem/45901706>.

Author: slavapestov

lib/IRGen/GenDecl.cpp

@@ -2428,9 +2428,11 @@ IRGenModule::getAddrOfLLVMVariableOrGOTEquivalent(LinkEntity entity,
   // Handle SILFunctions specially, because unlike other entities they aren't
   // variables and aren't kept in the GlobalVars table.
   if (entity.isSILFunction()) {
-    auto fn = getAddrOfSILFunction(entity.getSILFunction(), NotForDefinition);
-    if (entity.getSILFunction()->isDefinition()
-        && !isAvailableExternally(entity.getSILFunction()->getLinkage())) {
+    auto *silFn = entity.getSILFunction();
+    auto fn = getAddrOfSILFunction(silFn, NotForDefinition);
+    if (silFn->isDefinition() &&
+        !isAvailableExternally(silFn->getLinkage()) &&
+        this == IRGen.getGenModule(silFn)) {
       return {fn, ConstantReference::Direct};
     }
 

lib/IRGen/GenKeyPath.cpp

@@ -120,8 +120,8 @@ getAccessorForComputedComponent(IRGenModule &IGM,
   // If it's only externally available, we need a local thunk to relative-
   // reference.
   if (requirements.empty() &&
-      !LinkEntity::forSILFunction(accessor, false).isAvailableExternally(IGM)) {
-
+      !isAvailableExternally(accessor->getLinkage()) &&
+      &IGM == IGM.IRGen.getGenModule(accessor)) {
     return IGM.getAddrOfSILFunction(accessor, NotForDefinition);
   }
   auto accessorFn = IGM.getAddrOfSILFunction(accessor, NotForDefinition);
@@ -1030,33 +1030,23 @@ emitKeyPathComponent(IRGenModule &IGM,
       fields.add(llvm::ConstantExpr::getTruncOrBitCast(idValue, IGM.Int32Ty));
       break;
     }
-    
-    if (isInstantiableOnce) {
-      // No generic arguments or indexes, so we can invoke the
-      // getter/setter as is.
+
+    // Push the accessors, possibly thunked to marshal generic environment.
+    fields.addRelativeAddress(
+      getAccessorForComputedComponent(IGM, component, Getter,
+                                      genericEnv, requirements,
+                                      hasSubscriptIndices));
+    if (settable)
       fields.addRelativeAddress(
-        IGM.getAddrOfSILFunction(component.getComputedPropertyGetter(),
-                                 NotForDefinition));
-      if (settable)
-        fields.addRelativeAddress(
-          IGM.getAddrOfSILFunction(component.getComputedPropertySetter(),
-                                   NotForDefinition));
-    } else {
+        getAccessorForComputedComponent(IGM, component, Setter,
+                                        genericEnv, requirements,
+                                        hasSubscriptIndices));
+
+    if (!isInstantiableOnce) {
       // If there's generic context or subscript indexes, embed as
       // arguments in the component. Thunk the SIL-level accessors to give the
       // runtime implementation a polymorphically-callable interface.
-      
-      // Push the accessors, possibly thunked to marshal generic environment.
-      fields.addRelativeAddress(
-        getAccessorForComputedComponent(IGM, component, Getter,
-                                        genericEnv, requirements,
-                                        hasSubscriptIndices));
-      if (settable)
-        fields.addRelativeAddress(
-          getAccessorForComputedComponent(IGM, component, Setter,
-                                          genericEnv, requirements,
-                                          hasSubscriptIndices));
-      
+
       fields.addRelativeAddress(
         getLayoutFunctionForComputedComponent(IGM, component,
                                               genericEnv, requirements));

test/IRGen/Inputs/multithread_keypaths_other.swift

@@ -0,0 +1,4 @@
+public struct A {
+  // note: not public
+  var foo: Int { get { return 0 } set { } }
+}

test/IRGen/keypaths.sil

@@ -249,13 +249,30 @@ entry:
 }
 
 sil @k_id : $@convention(thin) () -> ()
-sil @k_get : $@convention(thin) (@in_guaranteed S) -> @out Int
+sil @k_get : $@convention(thin) (@in_guaranteed S) -> @out Int {
+bb0(%0 : @trivial $*Int, %1 : @trivial $*S):
+  unreachable
+}
+
+sil @l_get : $@convention(thin) (@in_guaranteed C) -> @out Int {
+bb0(%0 : @trivial $*Int, %1 : @trivial $*C):
+  unreachable
+}
 
-sil @l_get : $@convention(thin) (@in_guaranteed C) -> @out Int
-sil @l_set : $@convention(thin) (@in_guaranteed Int, @in_guaranteed C) -> ()
+sil @l_set : $@convention(thin) (@in_guaranteed Int, @in_guaranteed C) -> () {
+bb0(%0 : @trivial $*Int, %1 : @trivial $*C):
+  unreachable
+}
 
-sil @m_get : $@convention(thin) (@in_guaranteed S) -> @out @callee_guaranteed () -> @out ()
-sil @m_set : $@convention(thin) (@in_guaranteed @callee_guaranteed () -> @out (), @inout S) -> ()
+sil @m_get : $@convention(thin) (@in_guaranteed S) -> @out @callee_guaranteed () -> @out () {
+bb0(%0 : @trivial $*@callee_guaranteed () -> @out (), %1 : @trivial $*S):
+  unreachable
+}
+
+sil @m_set : $@convention(thin) (@in_guaranteed @callee_guaranteed () -> @out (), @inout S) -> () {
+bb0(%0 : @trivial $*@callee_guaranteed () -> @out (), %1 : @trivial $*S):
+  unreachable
+}
 
 sil @m2_get : $@convention(thin) (@in_guaranteed C2) -> @out @callee_guaranteed () -> @out ()
 sil @m2_set : $@convention(thin) (@in_guaranteed @callee_guaranteed () -> @out (), @inout C2) -> ()

test/IRGen/multithread_keypaths.swift

@@ -0,0 +1,11 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -c %S/Inputs/multithread_keypaths_other.swift %s -num-threads 2 -o %t/1.o -o %t/2.o -module-name multithread_keypaths
+// RUN: %target-swift-frontend -c %S/Inputs/multithread_keypaths_other.swift %s -num-threads 2 -o %t/1.o -o %t/2.o -module-name multithread_keypaths -enable-testing
+// RUN: %target-swift-frontend -c %S/Inputs/multithread_keypaths_other.swift %s -num-threads 2 -o %t/1.o -o %t/2.o -module-name multithread_keypaths -enable-resilience
+// RUN: %target-swift-frontend -c %S/Inputs/multithread_keypaths_other.swift %s -num-threads 2 -o %t/1.o -o %t/2.o -module-name multithread_keypaths -enable-testing -enable-resilience
+
+func f(_ k: WritableKeyPath<A, Int>) {}
+
+func g() {
+  f(\A.foo)
+}