Add check for libatomic requirement to Python build system

scripts/mk_util.py

@@ -314,6 +314,23 @@ def test_fpmath(cc):
         FPMATH_FLAGS=""
         return "UNKNOWN"
 
+def test_atomic_required(cc):
+    t = TempFile('tstatomic.cpp')
+    t.add("""
+    #include <atomic>
+    std::atomic<int> x;
+    std::atomic<short> y;
+    std::atomic<char> z;
+    std::atomic<long long> w;
+    int main() {
+        ++z;
+        ++y;
+        ++w;
+        return ++x;
+    }")
+    """)
+    t.commit()
+    return exec_compiler_cmd([cc, CPPFLAGS, '', 'tstatomic.cpp', LDFLAGS, '']) != 0
 
 def find_jni_h(path):
     for root, dirs, files in os.walk(path):
@@ -2600,6 +2617,9 @@ def mk_config():
         CXXFLAGS = '%s -fvisibility=hidden -fvisibility-inlines-hidden -c' % CXXFLAGS
         FPMATH = test_fpmath(CXX)
         CXXFLAGS = '%s %s' % (CXXFLAGS, FPMATH_FLAGS)
+        atomic_required = test_atomic_required(CXX)
+        if atomic_required:
+            LDFLAGS  = '%s -latomic' % LDFLAGS
         if LOG_SYNC:
             CXXFLAGS = '%s -DZ3_LOG_SYNC' % CXXFLAGS
         if SINGLE_THREADED:
@@ -2710,6 +2730,7 @@ def mk_config():
             print('Prefix:         %s' % PREFIX)
             print('64-bit:         %s' % is64())
             print('FP math:        %s' % FPMATH)
+            print('libatomic:      %s' % ('required' if atomic_required else 'not required'))
             print("Python pkg dir: %s" % PYTHON_PACKAGE_DIR)
             if GPROF:
                 print('gprof:          enabled')