@@ -259,7 +259,7 @@ jobs:

       strategy:

         fail-fast: false

         matrix:

-          arch: [amd64, x86, arm64]

+          arch: [amd64, x86, arm64, amd64-clang, x86-clang]

       name: "msbuild - ${{ matrix.arch }} - openssl"

       env:

@@ -627,7 +627,8 @@ if (BUILD_TESTING)

         check_linker_flag(C -Wl,--wrap=parse_line LD_SUPPORTS_WRAP)

     endif()

-    if (${LD_SUPPORTS_WRAP})

+    # Clang-cl (which is also MSVC) is wrongly detected to support wrap

+    if (NOT MSVC AND "${LD_SUPPORTS_WRAP}")

         list(APPEND unit_tests

             "test_argv"

             "test_tls_crypt"

@@ -122,6 +122,10 @@

             }

         },

         {

+            "name": "clangtoolset",

+            "toolset": "ClangCL"

+        },

+        {

             "name": "mingw-x64",

             "inherits": [ "base", "base-mingw", "x64-mingw" ]

         },

@@ -134,6 +138,10 @@

             "inherits": [ "base", "base-windows", "x64", "release" ]

         },

         {

+            "name": "win-amd64-clang-release",

+            "inherits": [ "base", "base-windows", "clangtoolset", "x64", "release" ]

+        },

+        {

             "name": "win-arm64-release",

             "inherits": [ "base", "base-windows", "arm64", "release" ]

         },

@@ -142,10 +150,18 @@

             "inherits": [ "base", "base-windows", "x86", "release" ]

         },

         {

+            "name": "win-x86-clang-release",

+            "inherits": [ "base", "base-windows", "clangtoolset", "x86", "release" ]

+        },

+        {

             "name": "win-amd64-debug",

             "inherits": [ "base", "base-windows", "x64", "debug" ]

         },

         {

+            "name": "win-amd64-clang-debug",

+            "inherits": [ "base", "base-windows", "clangtoolset", "x64", "debug" ]

+        },

+        {

             "name": "win-arm64-debug",

             "inherits": [ "base", "base-windows", "arm64", "debug" ]

         },

@@ -154,6 +170,10 @@

             "inherits": [ "base", "base-windows", "x86", "debug" ]

         },

         {

+            "name": "win-x86-clang-debug",

+            "inherits": [ "base", "base-windows", "clangtoolset", "x86", "debug" ]

+        },

+        {

             "name": "unix-native",

             "generator": "Ninja Multi-Config",

             "binaryDir": "out/build/unix"

@@ -174,6 +194,11 @@

             "configuration": "Release"

         },

         {

+            "name": "win-amd64-clang-release",

+            "configurePreset": "win-amd64-clang-release",

+            "configuration": "Release"

+        },

+        {

             "name": "win-arm64-release",

             "configurePreset": "win-arm64-release",

             "configuration": "Release"

@@ -184,11 +209,21 @@

             "configuration": "Release"

         },

         {

+            "name": "win-x86-clang-release",

+            "configurePreset": "win-x86-clang-release",

+            "configuration": "Release"

+        },

+        {

             "name": "win-amd64-debug",

             "configurePreset": "win-amd64-debug",

             "configuration": "Debug"

         },

         {

+            "name": "win-amd64-clang-debug",

+            "configurePreset": "win-amd64-clang-debug",

+            "configuration": "Debug"

+        },

+        {

             "name": "win-arm64-debug",

             "configurePreset": "win-arm64-debug",

             "configuration": "Debug"

@@ -199,6 +234,11 @@

             "configuration": "Debug"

         },

         {

+            "name": "win-x86-clang-debug",

+            "configurePreset": "win-x86-clang-debug",

+            "configuration": "Debug"

+        },

+        {

             "name": "unix-native",

             "configurePreset": "unix-native"

         }

@@ -209,18 +249,34 @@

             "configurePreset": "win-amd64-release"

         },

         {

+            "name": "win-amd64-clang-release",

+            "configurePreset": "win-amd64-clang-release"

+        },

+        {

             "name": "win-x86-release",

             "configurePreset": "win-x86-release"

         },

         {

+            "name": "win-x86-clang-release",

+            "configurePreset": "win-x86-clang-release"

+        },

+        {

             "name": "win-amd64-debug",

             "configurePreset": "win-amd64-debug"

         },

         {

+            "name": "win-amd64-clang-debug",

+            "configurePreset": "win-amd64-clang-debug"

+        },

+        {

             "name": "win-x86-debug",

             "configurePreset": "win-x86-debug"

         },

         {

+            "name": "win-x86-clang-debug",

+            "configurePreset": "win-x86-clang-debug"

+        },

+        {

             "name": "unix-native",

             "configurePreset": "unix-native"

         }

@@ -439,8 +439,10 @@ don't. */

 # define _GNU_SOURCE 1

 #endif

-

-#if defined(_WIN32)

+/* if inttypes.h is included this breaks rc.exe when using the ClangCL

+ * Toolchain as it pulls in a inttypes.h variant for clang that rc.exe does

+ * not understand (#include_next preprocessor directive) */

+#if defined(_WIN32) && !defined(RC_INVOKED)

 #include <inttypes.h>

 typedef uint32_t in_addr_t;

 typedef uint16_t in_port_t;

@@ -452,7 +454,7 @@ typedef uint16_t in_port_t;

 #define SIGTERM   15

 #endif

-#if defined(_MSC_VER)

+#if defined(_MSC_VER) && !defined(RC_INVOKED)

 #include <BaseTsd.h>

 typedef SSIZE_T ssize_t;

 #define strncasecmp strnicmp

@@ -303,7 +303,7 @@ cleanup_pAdapterList:

 UINT __stdcall

 FindSystemInfo(_In_ MSIHANDLE hInstall)

 {

-#ifdef _MSC_VER

+#ifdef DLLEXP_EXPORT

 #pragma comment(linker, DLLEXP_EXPORT)

 #endif

@@ -340,7 +340,7 @@ FindSystemInfo(_In_ MSIHANDLE hInstall)

 UINT __stdcall

 CloseOpenVPNGUI(_In_ MSIHANDLE hInstall)

 {

-#ifdef _MSC_VER

+#ifdef DLLEXP_EXPORT

 #pragma comment(linker, DLLEXP_EXPORT)

 #endif

     UNREFERENCED_PARAMETER(hInstall); /* This CA is does not interact with MSI session (report errors, access properties, tables, etc.). */

@@ -363,7 +363,7 @@ CloseOpenVPNGUI(_In_ MSIHANDLE hInstall)

 UINT __stdcall

 StartOpenVPNGUI(_In_ MSIHANDLE hInstall)

 {

-#ifdef _MSC_VER

+#ifdef DLLEXP_EXPORT

 #pragma comment(linker, DLLEXP_EXPORT)

 #endif

@@ -636,7 +636,7 @@ schedule_adapter_delete(

 UINT __stdcall

 EvaluateTUNTAPAdapters(_In_ MSIHANDLE hInstall)

 {

-#ifdef _MSC_VER

+#ifdef DLLEXP_EXPORT

 #pragma comment(linker, DLLEXP_EXPORT)

 #endif

@@ -789,7 +789,7 @@ EvaluateTUNTAPAdapters(_In_ MSIHANDLE hInstall)

                 {

                     goto cleanup_szDisplayName;

                 }

-#ifdef __GNUC__

+#if defined(__GNUC__) || defined(__clang__)

 /*

  * warning: enumeration value ‘MSICONDITION_TRUE’ not handled in switch

  * warning: enumeration value ‘MSICONDITION_NONE’ not handled in switch

@@ -809,7 +809,7 @@ EvaluateTUNTAPAdapters(_In_ MSIHANDLE hInstall)

                         free(szValue);

                         goto cleanup_szDisplayName;

                 }

-#ifdef __GNUC__

+#if defined(__GNUC__) || defined(__clang__)

 #pragma GCC diagnostic pop

 #endif

                 free(szValue);

@@ -965,7 +965,7 @@ CreateRebootFile(_In_z_ LPCWSTR szTmpDir)

 UINT __stdcall

 ProcessDeferredAction(_In_ MSIHANDLE hInstall)

 {

-#ifdef _MSC_VER

+#ifdef DLLEXP_EXPORT

 #pragma comment(linker, DLLEXP_EXPORT)

 #endif

@@ -1165,7 +1165,7 @@ cleanup_CoInitialize:

 UINT __stdcall

 CheckAndScheduleReboot(_In_ MSIHANDLE hInstall)

 {

-#ifdef _MSC_VER

+#ifdef DLLEXP_EXPORT

 #pragma comment(linker, DLLEXP_EXPORT)

 #endif

@@ -66,7 +66,11 @@ extern DWORD openvpnmsica_thread_data_idx;

 extern "C" {

 #endif

-#ifdef __GNUC__

+/* Ensure that clang-cl, which does not understand the cl specific

+ * preprocessor defines like #pragma comment(linker, DLLEXP_EXPORT)

+ * is handled the same way as mingw and uses the alternative instead

+ * and does not define DLLEXP_EXPORT */

+#if defined(__GNUC__) || defined(__clang__)

 #define DLLEXP_DECL __declspec(dllexport)

 #else

 #define DLLEXP_DECL

@@ -389,8 +389,9 @@ test_snprintf(void **state)

     /* Instead of trying to trick the compiler here, disable the warnings

      * for this unit test. We know that the results will be truncated

-     * and we want to test that */

-#if defined(__GNUC__)

+     * and we want to test that. Not we need the clang as clang-cl (msvc) does

+     * not define __GNUC__ like it does under UNIX(-like) platforms */

+#if defined(__GNUC__) || defined(__clang__)

 /* some clang version do not understand -Wformat-truncation, so ignore the

  * warning to avoid warnings/errors (-Werror) about unknown pragma/option */

 #if defined(__clang__)

@@ -418,7 +419,7 @@ test_snprintf(void **state)

     assert_int_equal(ret, 10);

     assert_int_equal(buf[9], '\0');

-#if defined(__GNUC__)

+#if defined(__GNUC__) || defined(__clang__)

 #pragma GCC diagnostic pop

 #if defined(__clang__)

 #pragma clang diagnostic pop