[embedded] Deserialize and import global variables in embedded Swift mode

Author: kubamracek

lib/SIL/IR/Linker.cpp

@@ -418,6 +418,15 @@ void SILLinkerVisitor::visitMetatypeInst(MetatypeInst *MI) {
   linkInVTable(C);
 }
 
+void SILLinkerVisitor::visitGlobalAddrInst(GlobalAddrInst *GAI) {
+  if (!Mod.getASTContext().LangOpts.hasFeature(Feature::Embedded))
+    return;
+
+  SILGlobalVariable *G = GAI->getReferencedGlobal();
+  G->setDeclaration(false);
+  G->setLinkage(stripExternalFromLinkage(G->getLinkage()));
+}
+
 //===----------------------------------------------------------------------===//
 //                             Top Level Routine
 //===----------------------------------------------------------------------===//

lib/SIL/IR/Linker.h

@@ -127,6 +127,7 @@ class SILLinkerVisitor : public SILInstructionVisitor<SILLinkerVisitor, void> {
   void visitAllocRefInst(AllocRefInst *ARI);
   void visitAllocRefDynamicInst(AllocRefDynamicInst *ARI);
   void visitMetatypeInst(MetatypeInst *MI);
+  void visitGlobalAddrInst(GlobalAddrInst *i);
 
 private:
   /// Cause a function to be deserialized, and visit all other functions

test/embedded/modules-globals-exec.swift

@@ -0,0 +1,61 @@
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+// RUN: %target-swift-frontend -emit-module -o %t/MyModule.swiftmodule %t/MyModule.swift -enable-experimental-feature Embedded -parse-as-library
+// RUN: %target-swift-frontend -c -I %t %t/Main.swift -enable-experimental-feature Embedded -o %t/a.o
+// RUN: %target-clang -x c -c %S/Inputs/tiny-runtime-dummy-refcounting.c -o %t/runtime.o
+// RUN: %target-clang -x c -c %S/Inputs/print.c -o %t/print.o
+// RUN: %target-clang %t/a.o %t/print.o %t/runtime.o -o %t/a.out
+// RUN: %target-run %t/a.out | %FileCheck %s
+
+// REQUIRES: executable_test
+// REQUIRES: VENDOR=apple
+// REQUIRES: OS=macosx
+
+// BEGIN MyModule.swift
+
+public var global_in_module_used_in_module = 0
+public var global_in_module_unused_in_module = 0
+
+public func foo() {
+  global_in_module_used_in_module += 1
+}
+
+// BEGIN Main.swift
+
+import MyModule
+
+@_silgen_name("putchar")
+func putchar(_: UInt8)
+
+public func print(_ s: StaticString, terminator: StaticString = "\n") {
+  var p = s.utf8Start
+  while p.pointee != 0 {
+    putchar(p.pointee)
+    p += 1
+  }
+  p = terminator.utf8Start
+  while p.pointee != 0 {
+    putchar(p.pointee)
+    p += 1
+  }
+}
+
+@_silgen_name("print_long")
+func print_long(_: Int)
+
+public func print(_ n: Int, terminator: StaticString = "\n") {
+    print_long(n)
+    print("", terminator: terminator)
+}
+
+func test() {
+  print("Testing globals...") // CHECK: Testing globals...
+  print(global_in_module_used_in_module) // CHECK-NEXT: 0
+  print(global_in_module_unused_in_module) // CHECK-NEXT: 0
+  foo()
+  print(global_in_module_used_in_module) // CHECK-NEXT: 1
+  print(global_in_module_unused_in_module) // CHECK-NEXT: 0
+}
+
+test()

test/embedded/modules-globals-many.swift

@@ -0,0 +1,45 @@
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+// RUN: %target-swift-frontend -emit-module -I %t -o %t/MyModuleA.swiftmodule %t/MyModuleA.swift -enable-experimental-feature Embedded -parse-as-library
+// RUN: %target-swift-frontend -emit-module -I %t -o %t/MyModuleB.swiftmodule %t/MyModuleB.swift -enable-experimental-feature Embedded -parse-as-library
+// RUN: %target-swift-frontend -emit-module -I %t -o %t/MyModuleC.swiftmodule %t/MyModuleC.swift -enable-experimental-feature Embedded -parse-as-library
+// RUN: %target-swift-frontend -emit-ir -I %t %t/Main.swift -enable-experimental-feature Embedded -parse-as-library | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+
+// Dependencies look like this:
+//
+//              ┌───  ModuleB  ◀─┐
+//  ModuleA  ◀──┤                ├───   Main
+//              └───  ModuleC  ◀─┘
+
+// BEGIN MyModuleA.swift
+
+public var global = 0
+
+public func foo() { global += 1 }
+
+// BEGIN MyModuleB.swift
+
+import MyModuleA
+
+public func foo() { global += 1 }
+
+// BEGIN MyModuleC.swift
+
+import MyModuleA
+
+public func foo() { global += 1 }
+
+// BEGIN Main.swift
+
+import MyModuleB
+import MyModuleC
+
+public func main() {
+  MyModuleB.foo()
+  MyModuleC.foo()
+}
+
+// CHECK: @"$s9MyModuleA6globalSivp" = global %TSi zeroinitializer

test/embedded/modules-globals.swift

@@ -0,0 +1,35 @@
+// RUN: %empty-directory(%t)
+// RUN: %{python} %utils/split_file.py -o %t %s
+
+// RUN: %target-swift-frontend -emit-module -o %t/MyModule.swiftmodule %t/MyModule.swift -enable-experimental-feature Embedded -parse-as-library
+// RUN: %target-swift-frontend -emit-ir -I %t %t/Main.swift -enable-experimental-feature Embedded -parse-as-library | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+
+// BEGIN MyModule.swift
+
+public var global_in_module_used_in_module = 0
+public var global_in_module_unused_in_module = 0
+
+public func foo() {
+  global_in_module_used_in_module += 1
+}
+
+// BEGIN Main.swift
+
+import MyModule
+
+public var global_in_client_used_in_client = 0
+public var global_in_client_unused_in_client = 0
+
+public func main() {
+  global_in_module_used_in_module = 42
+  global_in_module_unused_in_module = 42
+  global_in_client_used_in_client = 42
+  foo()
+}
+
+// CHECK: @"$s4Main022global_in_client_used_c1_D0Sivp" = global %TSi zeroinitializer
+// CHECK: @"$s4Main024global_in_client_unused_c1_D0Sivp" = global %TSi zeroinitializer
+// CHECK: @"$s8MyModule022global_in_module_used_d1_E0Sivp" = global %TSi zeroinitializer
+// CHECK: @"$s8MyModule024global_in_module_unused_d1_E0Sivp" = global %TSi zeroinitializer