Merge pull request #83825 from egorzhdan/egorzhdan/constexpr-in-namespace

[cxx-interop] Import constexpr globals in a namespace

Author: egorzhdan

lib/ClangImporter/ImportDecl.cpp

@@ -4599,7 +4599,7 @@ namespace {
         isStatic = true;
 
       // For now we don't import static constexpr. TODO: Lift this restriction.
-      if (isStatic && decl->isConstexpr())
+      if (isStatic && !isClangNamespace(dc) && decl->isConstexpr())
         return nullptr;
 
       auto introducer = Impl.shouldImportGlobalAsLet(decl->getType())

test/Interop/Cxx/namespace/Inputs/constexpr-in-namespace.h

@@ -0,0 +1,4 @@
+namespace NS1 {
+constexpr int myConstexprInt = 123;
+static constexpr int myStaticConstexprInt = 456;
+} // namespace NS1

test/Interop/Cxx/namespace/Inputs/module.modulemap

@@ -12,6 +12,11 @@ module ClassesSecondHeader {
   requires cplusplus
 }
 
+module ConstexprInNamespace {
+  header "constexpr-in-namespace.h"
+  requires cplusplus
+}
+
 module ExternWithinNamespace {
   header "extern-within-namespace.h"
   export *

test/Interop/Cxx/namespace/constexpr-in-namespace-module-interface.swift

@@ -0,0 +1,6 @@
+// RUN: %target-swift-ide-test -print-module -module-to-print=ConstexprInNamespace -I %S/Inputs -source-filename=x -cxx-interoperability-mode=upcoming-swift | %FileCheck %s
+
+// CHECK: enum NS1 {
+// CHECK:   static var myConstexprInt: Int32
+// CHECK:   static var myStaticConstexprInt: Int32
+// CHECK: }

test/Interop/Cxx/namespace/constexpr-in-namespace.swift

@@ -0,0 +1,17 @@
+// RUN: %target-run-simple-swift(-I %S/Inputs -cxx-interoperability-mode=upcoming-swift)
+// REQUIRES: executable_test
+
+import StdlibUnittest
+import ConstexprInNamespace
+
+var NamespacesTestSuite = TestSuite("Constexpr in namespace")
+
+NamespacesTestSuite.test("constexpr int") {
+  expectEqual(NS1.myConstexprInt, 123)
+}
+
+NamespacesTestSuite.test("static constexpr int") {
+  expectEqual(NS1.myStaticConstexprInt, 456)
+}
+
+runAllTests()