Fix building with Windows SDK and Clang-CL (#7337)

* Fix building with Windows SDK and Clang-CL

* Attempt to add Clang-CL to CI build configurations

* Fix typo

* Enable EHsc explicitly when using ClangCL due to it being default turned-off

* Override CMAKE_<LANG>_FLAGS instead due to Z3 resets the _INIT variants

.github/workflows/msvc-static-build-clang-cl.yml

@@ -0,0 +1,23 @@
+name: MSVC Clang-CL Static Build
+
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read # to fetch code (actions/checkout)
+
+jobs:
+  build:
+    runs-on: windows-2019
+    env:
+      BUILD_TYPE: Release
+    steps:
+    - name: Checkout Repo
+      uses: actions/checkout@v4
+
+    - name: Build
+      run: |
+        cmake -B build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DZ3_BUILD_LIBZ3_SHARED=OFF -DZ3_BUILD_LIBZ3_MSVC_STATIC=ON -T ClangCL -DCMAKE_C_FLAGS="/EHsc" -DCMAKE_CXX_FLAGS="/EHsc"
+        cmake --build build --config ${{ env.BUILD_TYPE }} --parallel
+        

src/util/mpz.cpp

@@ -46,10 +46,14 @@ Revision History:
 #define LEHMER_GCD
 #endif
 
-
-#if defined(__GNUC__)
+#ifdef __has_builtin
+    #define HAS_BUILTIN(X) __has_builtin(X)
+#else
+    #define HAS_BUILTIN(X) 0
+#endif
+#if HAS_BUILTIN(__builtin_ctz)
 #define _trailing_zeros32(X) __builtin_ctz(X)
-#elif defined(_WINDOWS) && (defined(_M_X86) || (defined(_M_X64) && !defined(_M_ARM64EC)))
+#elif defined(_WINDOWS) && (defined(_M_X86) || (defined(_M_X64) && !defined(_M_ARM64EC))) && !defined(__clang__)
 // This is needed for _tzcnt_u32 and friends.
 #include <immintrin.h>
 #define _trailing_zeros32(X) _tzcnt_u32(X)
@@ -62,11 +66,11 @@ static uint32_t _trailing_zeros32(uint32_t x) {
 #endif
 
 #if (defined(__LP64__) || defined(_WIN64)) && defined(_M_X64) && !defined(_M_ARM64EC)
- #if defined(__GNUC__)
- #define _trailing_zeros64(X) __builtin_ctzll(X)
- #else
- #define _trailing_zeros64(X) _tzcnt_u64(X)
- #endif
+#if HAS_BUILTIN(__builtin_ctzll)
+#define _trailing_zeros64(X) __builtin_ctzll(X)
+#elif !defined(__clang__)
+#define _trailing_zeros64(X) _tzcnt_u64(X)
+#endif
 #else
 static uint64_t _trailing_zeros64(uint64_t x) {
     uint64_t r = 0;
@@ -75,6 +79,8 @@ static uint64_t _trailing_zeros64(uint64_t x) {
 }
 #endif
 
+#undef HAS_BUILTIN
+
 unsigned trailing_zeros(uint32_t x) {
     return static_cast<unsigned>(_trailing_zeros32(x));
 }