Swift: preserve `-static` for static library swiftmodules

The `-static` is important for the emission of the module as it is
serialized into the swiftmodule which then is used by the Swift frontend
to decide how to link to the symbol (via the GOT or not, or the IAT on
Windows). This repairs building static libraries with Swift on Windows.

Source/cmNinjaTargetGenerator.cxx

@@ -1987,6 +1987,18 @@ void cmNinjaTargetGenerator::WriteSwiftObjectBuildStatement(
     return !isMultiThread && compileMode == cmSwiftCompileMode::Wholemodule;
   }();
 
+  // Without `-emit-library` or `-emit-executable`, targets with a single
+  // source file parse as a Swift script instead of like normal source. For
+  // non-executable targets, append this to ensure that they are parsed like a
+  // normal source.
+  if (target.GetType() != cmStateEnums::EXECUTABLE) {
+    this->LocalGenerator->AppendFlags(vars["FLAGS"], "-parse-as-library");
+  }
+
+  if (target.GetType() == cmStateEnums::STATIC_LIBRARY) {
+    this->LocalGenerator->AppendFlags(vars["FLAGS"], "-static");
+  }
+
   // Swift modules only make sense to emit from things that can be imported.
   // Executables that don't export symbols can't be imported, so don't try to
   // emit a swiftmodule for them. It will break.
@@ -2011,14 +2023,6 @@ void cmNinjaTargetGenerator::WriteSwiftObjectBuildStatement(
       vars["FLAGS"], cmStrCat(libraryLinkNameFlag, ' ', libraryLinkName));
   }
 
-  // Without `-emit-library` or `-emit-executable`, targets with a single
-  // source file parse as a Swift script instead of like normal source. For
-  // non-executable targets, append this to ensure that they are parsed like a
-  // normal source.
-  if (target.GetType() != cmStateEnums::EXECUTABLE) {
-    this->LocalGenerator->AppendFlags(vars["FLAGS"], "-parse-as-library");
-  }
-
   this->LocalGenerator->AppendFlags(vars["FLAGS"],
                                     this->GetFlags(language, config));
   vars["DEFINES"] = this->GetDefines(language, config);

Tests/RunCMake/Swift/RunCMakeTest.cmake

@@ -76,6 +76,12 @@ elseif(RunCMake_GENERATOR STREQUAL Ninja)
       # -v: verbose to capture executed commands -n: dry-run to avoid actually compiling
       run_cmake_command(ForceResponseFile-check ${CMAKE_COMMAND} --build ${ForceResponseFile_TEST_BINARY_DIR} -- -vn)
     endblock()
+
+    block()
+      set(SwiftLibraryModuleCommand_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/SwiftLibraryModuleCommand-build)
+      run_cmake(SwiftLibraryModuleCommand)
+      run_cmake_command(SwiftLibraryModuleCommand-check ${CMAKE_COMMAND} --build ${SwiftLibraryModuleCommand_TEST_BINARY_DIR} -- -n -v)
+    endblock()
   endif()
 elseif(RunCMake_GENERATOR STREQUAL "Ninja Multi-Config")
   if(CMake_TEST_Swift)

Tests/RunCMake/Swift/SwiftLibraryModuleCommand-check-stdout.txt

@@ -0,0 +1,3 @@
+.*swiftc(.exe)? .* -parse-as-library -static -emit-module .* -module-name StaticLibrary [^
+]*
+.*swiftc(.exe)? .* -parse-as-library -emit-module .* -module-name DynamicLibrary

Tests/RunCMake/Swift/SwiftLibraryModuleCommand.cmake

@@ -0,0 +1,8 @@
+if(POLICY CMP0157)
+  cmake_policy(SET CMP0157 NEW)
+endif()
+
+enable_language(Swift)
+
+add_library(StaticLibrary STATIC L.swift)
+add_library(DynamicLibrary SHARED L.swift)