[PackageCMO] Global var and accessor linkage should be kept private/hidden in SILGen.

This PR contains changes that ensure the following:
* Global accessor linkage is kept hidden if its decl is resilient.
  - LinkageLimit::Never is returned for Global Accessor if its decl is resilient.
  - Since it's kept hidden, the use site should not expect a call to a global accessor
    if the static var decl being accessed is resilient. The bypassing resilience logic
    in AbstractStorageDecl::isResilient(accessingModule, decl) has been removed; to be
    addressed in Package CMO optimization pass.
* sil_global linkage is kept private if its decl is resilient.

Resolves rdar://129829925

Author: elsh

lib/AST/Decl.cpp

@@ -3060,9 +3060,6 @@ bool AbstractStorageDecl::isResilient(ModuleDecl *M,
   case ResilienceExpansion::Maximal:
     if (M == getModuleContext())
       return false;
-    // Access non-resiliently if package optimization is enabled
-    if (bypassResilienceInPackage(M))
-      return false;
     return isResilient();
   }
   llvm_unreachable("bad resilience expansion");

lib/SIL/IR/SILDeclRef.cpp

@@ -464,7 +464,9 @@ static LinkageLimit getLinkageLimit(SILDeclRef constant) {
     return Limit::OnDemand;
 
   case Kind::GlobalAccessor:
-    return cast<VarDecl>(d)->isStrictlyResilient() ? Limit::NeverPublic : Limit::None;
+    // global unsafeMutableAddressor should be kept hidden if its decl
+    // is resilient.
+    return cast<VarDecl>(d)->isResilient() ? Limit::NeverPublic : Limit::None;
 
   case Kind::DefaultArgGenerator:
     // If the default argument is to be serialized, only use non-ABI public

lib/SILGen/SILGenGlobalVariable.cpp

@@ -42,8 +42,8 @@ SILGlobalVariable *SILGenModule::getSILGlobalVariable(VarDecl *gDecl,
 
   // Get the linkage for SILGlobalVariable.
   FormalLinkage formalLinkage;
-  if (gDecl->isResilient() &&
-      !gDecl->getModuleContext()->serializePackageEnabled())
+  // sil_global linkage should be kept private if its decl is resilient.
+  if (gDecl->isResilient())
     formalLinkage = FormalLinkage::Private;
   else
     formalLinkage = getDeclLinkage(gDecl);

test/IRGen/package_bypass_resilience_global_accessor.swift

@@ -0,0 +1,13 @@
+ // RUN: %empty-directory(%t)
+
+// RUN: %target-build-swift -module-name=File -package-name Pkg -I%t -emit-ir %s | %FileCheck %s --check-prefix=CHECK-IR-NONRES
+// RUN: %target-build-swift -module-name=File -package-name Pkg -I%t -emit-ir %s -enable-library-evolution | %FileCheck %s --check-prefix=CHECK-IR-RES
+// RUN: %target-build-swift -module-name=File -package-name Pkg -I%t -emit-ir %s -enable-library-evolution -Xfrontend -experimental-allow-non-resilient-access -Xfrontend -experimental-package-cmo | %FileCheck %s --check-prefix=CHECK-IR-RES
+
+public struct S {
+  public static var x = "hello world"
+}
+
+// CHECK-IR-NONRES: define{{( dllexport)?}}{{( protected)?}} swiftcc ptr @"$s4File1SV1xSSvau"()
+// CHECK-IR-RES: define hidden swiftcc ptr @"$s4File1SV1xSSvau"()
+

test/IRGen/package_global_accessor.swift

@@ -17,8 +17,8 @@
 
 /// To bypass resilience at use site, Client needs to be in the same package as its
 /// loaded module and also opt in with -experimental-package-bypass-resilience.
-// RUN: %target-swift-frontend -emit-silgen %t/Client.swift -I %t -module-name Client -package-name mypkg -experimental-package-bypass-resilience | %FileCheck %s --check-prefixes=CHECK,CHECK-BYPASS
-// RUN: %target-swift-frontend -emit-silgen %t/Client.swift -I %t -module-name Client -package-name mypkg -experimental-package-bypass-resilience -enable-library-evolution | %FileCheck %s --check-prefixes=CHECK,CHECK-BYPASS
+// RUN: %target-swift-frontend -emit-silgen %t/Client.swift -I %t -module-name Client -package-name mypkg -experimental-package-bypass-resilience | %FileCheck %s --check-prefixes=CHECK,CHECK-ACCESS
+// RUN: %target-swift-frontend -emit-silgen %t/Client.swift -I %t -module-name Client -package-name mypkg -experimental-package-bypass-resilience -enable-library-evolution | %FileCheck %s --check-prefixes=CHECK,CHECK-ACCESS
 
 /// Utils can be built with both -enable-testing and -experimental-allow-non-resilient-access.
 // RUN: rm -rf %t/Utils.swiftmodule
@@ -158,7 +158,7 @@ func foo() {
 // CHECK: sil hidden [ossa] @$s6Client3fooyyF : $@convention(thin) () -> () {
 // CHECK-DEFAULT: function_ref @$s5Utils9PkgStructV6pkgVarSivg : $@convention(method) (@in_guaranteed PkgStruct) -> Int
 // CHECK-DEFAULT: sil package_external @$s5Utils9PkgStructV6pkgVarSivg : $@convention(method) (@in_guaranteed PkgStruct) -> Int
-// CHECK-BYPASS:  struct_element_addr {{.*}} : $*PkgStruct, #PkgStruct.pkgVar
+// CHECK-ACCESS:  function_ref @$s5Utils9PkgStructV6pkgVarSivg
 // CHECK-NONRES: struct_extract {{.*}} : $PkgStruct, #PkgStruct.pkgVar
 
 func bar() {
@@ -168,5 +168,5 @@ func bar() {
 // CHECK: sil hidden [ossa] @$s6Client3baryyF : $@convention(thin) () -> () {
 // CHECK-DEFAULT: function_ref @$s5Utils9PubStructV6pubVarSivg : $@convention(method) (@in_guaranteed PubStruct) -> Int
 // CHECK-DEFAULT: sil @$s5Utils9PubStructV6pubVarSivg : $@convention(method) (@in_guaranteed PubStruct) -> Int
-// CHECK-BYPASS:  struct_element_addr {{.*}} : $*PubStruct, #PubStruct.pubVar
+// CHECK-ACCESS: function_ref @$s5Utils9PubStructV6pubVarSivg
 // CHECK-NONRES: struct_extract {{.*}} : $PubStruct, #PubStruct.pubVar

test/SILGen/package_bypass_resilience.swift renamed to test/SILGen/package_allow_non_resilient_access.swift

@@ -0,0 +1,54 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+
+// RUN: %target-build-swift -module-name=Lib -package-name Pkg -I%t -emit-silgen %t/Lib.swift -o %t/Lib-nonres.sil
+// RUN: %FileCheck %s --check-prefix=CHECK-NONRES < %t/Lib-nonres.sil
+// RUN: %target-build-swift -module-name=Lib -package-name Pkg -I%t -emit-silgen -O -wmo %t/Lib.swift | %FileCheck %s --check-prefix=CHECK-NONRES
+// RUN: %target-build-swift -module-name=Lib -package-name Pkg -I%t -emit-silgen %t/Lib.swift -enable-library-evolution -o %t/Lib-res.sil
+// RUN: %FileCheck %s < %t/Lib-res.sil
+// RUN: %target-build-swift -module-name=Lib -package-name Pkg -I%t -emit-silgen %t/Lib.swift -enable-library-evolution -O -wmo | %FileCheck %s
+// RUN: %target-build-swift -module-name=Lib -package-name Pkg -I%t -emit-silgen %t/Lib.swift -enable-library-evolution -Xfrontend -experimental-allow-non-resilient-access -Xfrontend -experimental-package-cmo -O -wmo | %FileCheck %s
+
+// RUN: %target-build-swift -module-name=Lib -package-name Pkg -I%t -emit-module %t/Lib.swift -enable-library-evolution -Xfrontend -experimental-allow-non-resilient-access -Xfrontend -experimental-package-cmo -O -wmo -o %t/Lib.swiftmodule
+// RUN: %target-build-swift -module-name=Client -package-name Pkg -I%t -emit-silgen %t/Client.swift -I %t | %FileCheck %s --check-prefix=CHECK-CLIENT
+
+//--- Client.swift
+import Lib
+public func client() {
+  /// Should not be calling S.x.unsafeMutableAddressor when accessing resilient global var;
+  /// instead, should be calling the opaque getter.
+  // CHECK-CLIENT-NOT: s3Lib1SV1xSSvau
+  // CHECK-CLIENT: function_ref @$s3Lib1SV1xSSvgZ
+  print(S.x)
+}
+
+//--- Lib.swift
+public struct S {
+  public static var x = "hello world"
+}
+
+// one-time initialization token for x
+// CHECK-NONRES: sil_global private @$s3Lib1SV1x_Wz : $Builtin.Word
+// CHECK: sil_global private @$s3Lib1SV1x_Wz : $Builtin.Word
+
+// static S.x
+// CHECK-NONRES: sil_global @$s3Lib1SV1xSSvpZ : $String
+// CHECK: sil_global private @$s3Lib1SV1xSSvpZ : $String
+
+// one-time initialization function for x
+// CHECK-NONRES: sil private [global_init_once_fn] [ossa] @$s3Lib1SV1x_WZ : $@convention(c) (Builtin.RawPointer) -> () {
+// CHECK: sil private [global_init_once_fn] [ossa] @$s3Lib1SV1x_WZ : $@convention(c) (Builtin.RawPointer) -> () {
+
+// S.x.unsafeMutableAddressor
+// CHECK-NONRES: sil [global_init] [ossa] @$s3Lib1SV1xSSvau : $@convention(thin) () -> Builtin.RawPointer {
+// CHECK: sil hidden [global_init] [ossa] @$s3Lib1SV1xSSvau : $@convention(thin) () -> Builtin.RawPointer {
+// CHECK: global_addr @$s3Lib1SV1x_Wz
+// CHECK: address_to_pointer
+// function_ref one-time initialization function for x
+// CHECK: function_ref @$s3Lib1SV1x_WZ
+// CHECK: global_addr @$s3Lib1SV1xSSvpZ
+// CHECK: address_to_pointer
+
+// static S.x.getter
+// CHECK-NONRES: sil [transparent] [serialized] [ossa] @$s3Lib1SV1xSSvgZ : $@convention(method) (@thin S.Type) -> @owned String {
+// CHECK: sil [ossa] @$s3Lib1SV1xSSvgZ : $@convention(method) (@thin S.Type) -> @owned String {

test/SILGen/package_global_accessor.swift

@@ -41,7 +41,8 @@ public func inUsePubStruct(_ arg: Int) -> PubStruct {
 // CHECK-MAIN: sil [ossa] @$s4Main12usePubStructy3Lib0cD0VSiF : $@convention(thin) (Int) -> @out PubStruct {
 public func usePubStruct(_ arg: Int) -> PubStruct {
   var p = PubStruct(1)
-  // CHECK-MAIN: struct_element_addr {{.*}} : $*PubStruct, #PubStruct.pub
+  // CHECK-MAIN: function_ref @$s3Lib9PubStructVyACSicfC
+  // CHECK-MAIN: function_ref @$s3Lib9PubStructV3pubSivM
   p.pub += arg
   return p
 }
@@ -58,15 +59,17 @@ package func inUseUfiPkgStruct(_ arg: Int) -> UfiPkgStruct {
 // CHECK-MAIN: sil package [ossa] @$s4Main15useUfiPkgStructy3Lib0cdE0VSiF : $@convention(thin) (Int) -> @out UfiPkgStruct {
 package func useUfiPkgStruct(_ arg: Int) -> UfiPkgStruct {
   var p = UfiPkgStruct(1)
-  // CHECK-MAIN: struct_element_addr {{.*}} : $*UfiPkgStruct, #UfiPkgStruct.ufiPkg
+  // CHECK-MAIN: function_ref @$s3Lib12UfiPkgStructVyACSicfC
+  // CHECK-MAIN: function_ref @$s3Lib12UfiPkgStructV03ufiC0SivM
   p.ufiPkg += arg
   return p
 }
 
 // CHECK-MAIN: sil package [ossa] @$s4Main12usePkgStructy3Lib0cD0VSiF : $@convention(thin) (Int) -> @out PkgStruct {
 package func usePkgStruct(_ arg: Int) -> PkgStruct {
   var p = PkgStruct(1)
-  // CHECK-MAIN: struct_element_addr {{.*}} : $*PkgStruct, #PkgStruct.pkg
+  // CHECK-MAIN: function_ref @$s3Lib9PkgStructVyACSicfC
+  // CHECK-MAIN: function_ref @$s3Lib9PkgStructV3pkgSivM
   p.pkg += arg
   return p
 }