C++ support; test_cext and test_cppext

Author: vstinner

Include/pymacro.h

@@ -48,7 +48,7 @@
 
 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
 #  define Py_BUILD_ASSERT_EXPR(cond) \
-    (sizeof(struct { _Static_assert(cond, #cond); int dummy; }), \
+    ((void)sizeof(struct { int dummy; _Static_assert(cond, #cond); }), \
      0)
 #else
    /* Assert a build-time dependency, as an expression.
@@ -68,9 +68,13 @@
     (sizeof(char [1 - 2*!(cond)]) - 1)
 #endif
 
-#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+#if ((defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) \
+     || (defined(__cplusplus) && __cplusplus >= 201103L))
    // Use static_assert() on C11 and newer
-#  define Py_BUILD_ASSERT(cond) static_assert((cond), #cond)
+#  define Py_BUILD_ASSERT(cond) \
+        do { \
+            static_assert((cond), #cond); \
+        } while (0)
 #else
 #  define Py_BUILD_ASSERT(cond)  \
         do { \

Lib/test/test_cext/extension.c

@@ -44,6 +44,11 @@ _testcext_exec(PyObject *module)
         return -1;
     }
 #endif
+
+    // test Py_BUILD_ASSERT() and Py_BUILD_ASSERT_EXPR()
+    Py_BUILD_ASSERT(sizeof(int) == sizeof(unsigned int));
+    assert(Py_BUILD_ASSERT_EXPR(sizeof(int) == sizeof(unsigned int)) == 0);
+
     return 0;
 }
 

Lib/test/test_cppext/extension.cpp

@@ -225,6 +225,10 @@ _testcppext_exec(PyObject *module)
     if (!result) return -1;
     Py_DECREF(result);
 
+    // test Py_BUILD_ASSERT() and Py_BUILD_ASSERT_EXPR()
+    Py_BUILD_ASSERT(sizeof(int) == sizeof(unsigned int));
+    assert(Py_BUILD_ASSERT_EXPR(sizeof(int) == sizeof(unsigned int)) == 0);
+
     return 0;
 }