Eager specializer: Fix pre-specialization of imported code

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -943,6 +943,11 @@ SILPassPipelinePlan::getOnonePassPipeline(const SILOptions &Options) {
   // be no need to run another analysis of copies at -Onone.
   P.addMandatoryARCOpts();
 
+  // Create pre-specializations.
+  // This needs to run pre-serialization because it needs to identify native
+  // inlinable functions from imported ones.
+  P.addOnonePrespecializations();
+
   // First serialize the SIL if we are asked to.
   P.startPipeline("Serialization");
   P.addSerializeSILPass();
@@ -962,9 +967,6 @@ SILPassPipelinePlan::getOnonePassPipeline(const SILOptions &Options) {
     P.addAssumeSingleThreaded();
   }
 
-  // Create pre-specializations.
-  P.addOnonePrespecializations();
-
   // Has only an effect if the -sil-based-debuginfo option is specified.
   P.addSILDebugInfoGenerator();
 

lib/SILOptimizer/Transforms/EagerSpecializer.cpp

@@ -853,6 +853,14 @@ void EagerSpecializerTransform::run() {
         assert(success);
       }
       onlyCreatePrespecializations = true;
+    } else if (targetFunc->getLinkage() == SILLinkage::Shared) {
+      // We have `shared` linkage if we deserialize a public serialized
+      // function.
+      // That means we are loading it from another module. In this case, we
+      // don't want to create a pre-specialization.
+      SpecializedFuncs.push_back(nullptr);
+      ReInfoVec.emplace_back(ReabstractionInfo());
+      continue;
     }
     ReInfoVec.emplace_back(FuncBuilder.getModule().getSwiftModule(),
                            FuncBuilder.getModule().isWholeModule(), targetFunc,

test/SILOptimizer/eager_specialize.sil

@@ -848,6 +848,24 @@ bb0(%0 : $*T):
   return %8 : $Builtin.Int64
 }
 
+// Don't specialize `shared` definitions they are imported from another module.
+// CHECK-NOT: sil @$s24testDontSpecializeSharedSi_Ts5
+sil shared [_specialize exported: true, kind: full, where T == Int] @testDontSpecializeShared : $@convention(thin) <T>(@in T) -> () {
+bb(%0: $*T):
+ destroy_addr %0 : $*T
+ %t = tuple()
+ return %t : $()
+}
+
+// But do specialize `shared` definitions when they are target from another // function.
+// CHECK: sil @$s24testDontSpecializeSharedSd_Ts5
+sil shared [_specialize exported: true, kind: full, target: "testDontSpecializeShared" ,where T == Double] @butSpecializeWhenTargetIsPresent : $@convention(thin) <T>(@in T) -> () {
+bb(%0: $*T):
+ destroy_addr %0 : $*T
+ %t = tuple()
+ return %t : $()
+}
+
 sil_vtable ClassUsingThrowingP {
   #ClassUsingThrowingP.init!allocator: (ClassUsingThrowingP.Type) -> () -> ClassUsingThrowingP : @$s34eager_specialize_throwing_function19ClassUsingThrowingPCACycfC	// ClassUsingThrowingP.__allocating_init()
   #ClassUsingThrowingP.init!initializer: (ClassUsingThrowingP.Type) -> () -> ClassUsingThrowingP : @$s34eager_specialize_throwing_function19ClassUsingThrowingPCACycfc	// ClassUsingThrowingP.init()

test/Serialization/serialize_attr.swift

@@ -79,6 +79,6 @@ public class CC<T : PP> {
   }
 }
 
-// CHECK-DAG: sil [serialized] [_specialize exported: false, kind: full, where T == Int, U == Float] [canonical] [ossa] @$s14serialize_attr14specializeThis_1uyx_q_tr0_lF : $@convention(thin) <T, U> (@in_guaranteed T, @in_guaranteed U) -> () {
+// CHECK-DAG: sil [serialized] [canonical] [ossa] @$s14serialize_attr14specializeThis_1uyx_q_tr0_lF : $@convention(thin) <T, U> (@in_guaranteed T, @in_guaranteed U) -> () {
 
-// CHECK-DAG: sil [serialized] [noinline] [_specialize exported: false, kind: full, where T == RR, U == SS] [canonical] [ossa] @$s14serialize_attr2CCC3foo_1gqd___AA2GGVyxGtqd___AHtAA2QQRd__lF : $@convention(method) <T where T : PP><U where U : QQ> (@in_guaranteed U, GG<T>, @guaranteed CC<T>) -> (@out U, GG<T>) {
+// CHECK-DAG: sil [serialized] [noinline] [canonical] [ossa] @$s14serialize_attr2CCC3foo_1gqd___AA2GGVyxGtqd___AHtAA2QQRd__lF : $@convention(method) <T where T : PP><U where U : QQ> (@in_guaranteed U, GG<T>, @guaranteed CC<T>) -> (@out U, GG<T>) {

test/sil-passpipeline-dump/basic.test-sh

@@ -2,13 +2,13 @@
 
 // CHECK: ---
 // CHECK: name:            Non-Diagnostic Mandatory Optimizations
-// CHECK: passes:          [ "for-each-loop-unroll", "mandatory-combine",
-// CHECK: "mandatory-arc-opts" ]
+// CHECK: passes:          [ "for-each-loop-unroll", "mandatory-combine", "mandatory-arc-opts",
+// CHECK: "onone-prespecializer" ]
 // CHECK: ---
 // CHECK: name:            Serialization
 // CHECK: passes:          [ "serialize-sil", "sil-onone-debuginfo-canonicalizer",
 // CHECK-NEXT:               "ownership-model-eliminator" ]
 // CHECK: ---
 // CHECK: name:            Rest of Onone
-// CHECK: passes:          [ "use-prespecialized", "onone-prespecializer", "sil-debuginfo-gen" ]
+// CHECK: passes:          [ "use-prespecialized", "sil-debuginfo-gen" ]
 // CHECK: ...