[ClosureSpecializer] use shared linkage for new functions.

This avoids unresolved-symbol errors in case the original function has external linkage.

Author: eeckstein

lib/SILOptimizer/IPO/ClosureSpecializer.cpp

@@ -547,7 +547,12 @@ ClosureSpecCloner::initCloned(const CallSiteDescriptor &CallSiteDesc,
   // We make this function bare so we don't have to worry about decls in the
   // SILArgument.
   auto *Fn = M.getOrCreateFunction(
-      ClosureUser->getLinkage(), ClonedName, ClonedTy,
+      // It's important to use a shared linkage for the specialized function
+      // and not the original linkage.
+      // Otherwise the new function could have an external linkage (in case the
+      // original function was de-serialized) and would not be code-gen'd.
+      getSpecializedLinkage(ClosureUser, ClosureUser->getLinkage()),
+      ClonedName, ClonedTy,
       ClosureUser->getContextGenericParams(), ClosureUser->getLocation(),
       IsBare, ClosureUser->isTransparent(), ClosureUser->isFragile(),
       ClosureUser->isThunk(), ClosureUser->getClassVisibility(),

test/SILOptimizer/closure_specialize.sil

@@ -3,12 +3,12 @@
 import Builtin
 import Swift
 
-// CHECK-LABEL: sil [noinline] @_TTSf1cl35_TFF7specgen6callerFSiT_U_FTSiSi_T_Si___TF7specgen12take_closureFFTSiSi_T_T_ : $@convention(thin) (Int) -> () {
+// CHECK-LABEL: sil shared [noinline] @_TTSf1cl35_TFF7specgen6callerFSiT_U_FTSiSi_T_Si___TF7specgen12take_closureFFTSiSi_T_T_ : $@convention(thin) (Int) -> () {
 // CHECK: bb0(%0 : $Int)
 // CHECK: function_ref @_TFF7specgen6callerFSiT_U_FTSiSi_T_
 // CHECK: partial_apply
 
-// CHECK-LABEL: sil [noinline] @_TTSf1cl27_TF7specgen6calleeFTSiSi_T____TF7specgen12take_closureFFTSiSi_T_T_ : $@convention(thin) () -> () {
+// CHECK-LABEL: sil shared [noinline] @_TTSf1cl27_TF7specgen6calleeFTSiSi_T____TF7specgen12take_closureFFTSiSi_T_T_ : $@convention(thin) () -> () {
 // CHECK-NEXT: bb0:
 // CHECK: [[FUN:%.*]] = function_ref @_TF7specgen6calleeFTSiSi_T_ : $@convention(thin) (Int, Int) -> ()
 // CHECK: thin_to_thick_function [[FUN]] : $@convention(thin) (Int, Int) -> () to $@callee_owned (Int, Int) -> ()
@@ -24,12 +24,12 @@ bb0(%0 : $@callee_owned (Int, Int) -> ()):
   return %9999 : $()
 }
 
-// CHECK-LABEL: sil [noinline] @_TTSf1cl35_TFF7specgen6callerFSiT_U_FTSiSi_T_Si___TF7specgen13take_closure2FFTSiSi_T_T_ : $@convention(thin) (Int) -> () {
+// CHECK-LABEL: sil shared [noinline] @_TTSf1cl35_TFF7specgen6callerFSiT_U_FTSiSi_T_Si___TF7specgen13take_closure2FFTSiSi_T_T_ : $@convention(thin) (Int) -> () {
 // CHECK: bb0(%0 : $Int)
 // CHECK: [[FUN:%.*]] = function_ref @_TFF7specgen6callerFSiT_U_FTSiSi_T_
 // CHECK: partial_apply [[FUN]](
 
-// CHECK-LABEL: sil [noinline] @_TTSf1cl27_TF7specgen6calleeFTSiSi_T____TF7specgen13take_closure2FFTSiSi_T_T_ : $@convention(thin) () -> () {
+// CHECK-LABEL: sil shared [noinline] @_TTSf1cl27_TF7specgen6calleeFTSiSi_T____TF7specgen13take_closure2FFTSiSi_T_T_ : $@convention(thin) () -> () {
 // CHECK-NEXT: bb0:
 // CHECK: [[FUN:%.*]] = function_ref @_TF7specgen6calleeFTSiSi_T_ : $@convention(thin) (Int, Int) -> ()
 // CHECK: thin_to_thick_function [[FUN]] : $@convention(thin) (Int, Int) -> () to $@callee_owned (Int, Int) -> ()
@@ -163,6 +163,7 @@ bb0(%0 : $A, %1 : $A):
   return %4 : $()
 }
 
+// CHECK-LABEL: sil shared {{.*}} @_TTS{{.*}}use_closure : $@convention(thin) (@owned A) -> () {
 sil hidden [noinline] @use_closure : $@convention(thin) (@owned @callee_owned (@owned A) -> ()) -> () {
 bb0(%0 : $@callee_owned (@owned A) -> ()):
   %1 = alloc_ref $A

test/SILOptimizer/closure_specialize_consolidated.sil

@@ -87,14 +87,14 @@ bb0(%0 : $Builtin.NativeObject, %1 : $Builtin.Int32, %2 : $Builtin.NativeObject,
   return %9999 : $()
 }
 
-// CHECK-LABEL: sil @_TTSf1cl20large_closure_calleeBoBi32_BoBo_n_n_n_n__owned_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject, @owned Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @owned Builtin.NativeObject) -> () {
+// CHECK-LABEL: sil shared @_TTSf1cl20large_closure_calleeBoBi32_BoBo_n_n_n_n__owned_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject, @owned Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @owned Builtin.NativeObject) -> () {
 // CHECK: bb0
 // CHECK: [[FUN:%.*]] = function_ref @large_closure_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject, Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> ()
 // CHECK: [[CLOSURE:%.*]] = partial_apply [[FUN]](
 // CHECK: apply [[CLOSURE]](
 // CHECK: release_value [[CLOSURE]]
 
-// CHECK-LABEL: sil @_TTSf1cl20small_closure_callee_n_n_n_n__owned_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> () {
+// CHECK-LABEL: sil shared @_TTSf1cl20small_closure_callee_n_n_n_n__owned_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> () {
 // CHECK: bb0
 // CHECK: [[FUN:%.*]] = function_ref @small_closure_callee
 // CHECK: [[CLOSURE:%.*]] = thin_to_thick_function [[FUN]] : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> () to $@callee_owned (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> ()
@@ -112,14 +112,14 @@ bb0(%0 : $@callee_owned (Builtin.NativeObject, Builtin.Int32, @owned Builtin.Nat
   return %9999 : $()
 }
 
-// CHECK-LABEL: sil @_TTSf1cl20large_closure_calleeBoBi32_BoBo_n_n_n_n__guaranteed_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject, @owned Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @owned Builtin.NativeObject) -> () {
+// CHECK-LABEL: sil shared @_TTSf1cl20large_closure_calleeBoBi32_BoBo_n_n_n_n__guaranteed_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject, @owned Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @owned Builtin.NativeObject) -> () {
 // CHECK: bb0(%0 : $Builtin.NativeObject, %1 : $Builtin.Int32, %2 : $Builtin.NativeObject, %3 : $Builtin.NativeObject, %4 : $Builtin.NativeObject, %5 : $Builtin.Int32, %6 : $Builtin.NativeObject, %7 : $Builtin.NativeObject):
 // CHECK: [[FUN:%.*]] = function_ref @large_closure_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject, Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> ()
 // CHECK: [[CLOSURE:%.*]] = partial_apply [[FUN]](
 // CHECK: apply [[CLOSURE]](
 // CHECK: release_value [[CLOSURE]]
 
-// CHECK-LABEL: sil @_TTSf1cl20small_closure_callee_n_n_n_n__guaranteed_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> () {
+// CHECK-LABEL: sil shared @_TTSf1cl20small_closure_callee_n_n_n_n__guaranteed_apply_callee : $@convention(thin) (Builtin.NativeObject, Builtin.Int32, @owned Builtin.NativeObject, @guaranteed Builtin.NativeObject) -> () {
 // CHECK: bb0(%0 : $Builtin.NativeObject, %1 : $Builtin.Int32, %2 : $Builtin.NativeObject, %3 : $Builtin.NativeObject):
 // CHECK: [[FUN:%.*]] = function_ref @small_closure_callee
 // CHECK: [[CLOSURE:%.*]] = thin_to_thick_function [[FUN]] :

test/SILOptimizer/closure_specialize_simple.sil

@@ -5,7 +5,7 @@ import Swift
 
 sil @simple_partial_apply_fun : $@convention(thin) (Builtin.Int1, Builtin.Int1) -> Builtin.Int1
 
-// CHECK-LABEL: sil @_TTSf1cl24simple_partial_apply_funBi1___simple_partial_apply_caller : $@convention(thin) (Builtin.Int1) -> Builtin.Int1 {
+// CHECK-LABEL: sil shared @_TTSf1cl24simple_partial_apply_funBi1___simple_partial_apply_caller : $@convention(thin) (Builtin.Int1) -> Builtin.Int1 {
 // CHECK: bb0([[CAPTURED_ARG:%.*]] : $Builtin.Int1):
 // CHECK: [[CLOSED_OVER_FUN:%.*]] = function_ref @simple_partial_apply_fun :
 // CHECK: [[NEW_PAI:%.*]] = partial_apply [[CLOSED_OVER_FUN]]