keep C++ code out of C files and vice-versa by splitting module preamble...

keep C++ code out of C files and vice-versa by splitting module preamble (original patch by Lars Mans)

Cython/Compiler/ModuleNode.py

@@ -562,6 +562,9 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
             self.generate_cvariable_declarations(module, modulecode, defined_here)
             self.generate_cfunction_declarations(module, modulecode, defined_here)
 
+    def _put_setup_code(self, code, name):
+        code.put(UtilityCode.load_as_string(name, "ModuleSetupCode.c")[1])
+
     def generate_module_preamble(self, env, cimported_modules, metadata, code):
         code.put_generated_by()
         if metadata:
@@ -583,7 +586,12 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         from .. import __version__
         code.putln('#define CYTHON_ABI "%s"' % __version__.replace('.', '_'))
 
-        code.put(UtilityCode.load_as_string("CModulePreamble", "ModuleSetupCode.c")[1])
+        self._put_setup_code(code, "CModulePreamble")
+        if env.context.options.cplus:
+            self._put_setup_code(code, "CppInitCode")
+        else:
+            self._put_setup_code(code, "CInitCode")
+        self._put_setup_code(code, "MathInitCode")
 
         code.put("""
 #if PY_MAJOR_VERSION >= 3
@@ -603,11 +611,6 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
         self.generate_extern_c_macro_definition(code)
         code.putln("")
 
-        code.putln("#if defined(WIN32) || defined(MS_WINDOWS)")
-        code.putln("#define _USE_MATH_DEFINES")
-        code.putln("#endif")
-        code.putln("#include <math.h>")
-
         code.putln("#define %s" % Naming.h_guard_prefix + self.api_name(env))
         code.putln("#define %s" % Naming.api_guard_prefix + self.api_name(env))
         self.generate_includes(env, cimported_modules, code)

Cython/Utility/ModuleSetupCode.c

@@ -200,20 +200,7 @@ typedef struct {
 #define __Pyx_PyType_AsAsync(obj) NULL
 #endif
 
-/* inline attribute */
-#ifndef CYTHON_INLINE
-  #if defined(__GNUC__)
-    #define CYTHON_INLINE __inline__
-  #elif defined(_MSC_VER)
-    #define CYTHON_INLINE __inline
-  #elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
-    #define CYTHON_INLINE inline
-  #else
-    #define CYTHON_INLINE
-  #endif
-#endif
-
-/* restrict */
+// restrict
 #ifndef CYTHON_RESTRICT
   #if defined(__GNUC__)
     #define CYTHON_RESTRICT __restrict__
@@ -226,22 +213,32 @@ typedef struct {
   #endif
 #endif
 
-#ifdef NAN
-#define __PYX_NAN() ((float) NAN)
-#else
-static CYTHON_INLINE float __PYX_NAN() {
-  /* Initialize NaN. The sign is irrelevant, an exponent with all bits 1 and
-   a nonzero mantissa means NaN. If the first bit in the mantissa is 1, it is
-   a quiet NaN. */
-  float value;
-  memset(&value, 0xFF, sizeof(value));
-  return value;
-}
+#define __Pyx_void_to_None(void_result) (void_result, Py_INCREF(Py_None), Py_None)
+
+
+/////////////// CInitCode ///////////////
+
+// inline attribute
+#ifndef CYTHON_INLINE
+  #if defined(__GNUC__)
+    #define CYTHON_INLINE __inline__
+  #elif defined(_MSC_VER)
+    #define CYTHON_INLINE __inline
+  #elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
+    #define CYTHON_INLINE inline
+  #else
+    #define CYTHON_INLINE
+  #endif
 #endif
 
-#define __Pyx_void_to_None(void_result) (void_result, Py_INCREF(Py_None), Py_None)
 
-#ifdef __cplusplus
+/////////////// CppInitCode ///////////////
+
+// inline attribute
+#ifndef CYTHON_INLINE
+  #define CYTHON_INLINE inline
+#endif
+
 // Work around clang bug http://stackoverflow.com/questions/21847816/c-invoke-nested-template-class-destructor
 template<typename T>
 void __Pyx_call_destructor(T* x) {
@@ -259,7 +256,28 @@ class __Pyx_FakeReference {
   private:
     T *ptr;
 };
+
+
+/////////////// MathInitCode ///////////////
+
+#if defined(WIN32) || defined(MS_WINDOWS)
+  #define _USE_MATH_DEFINES
 #endif
+#include <math.h>
+
+#ifdef NAN
+#define __PYX_NAN() ((float) NAN)
+#else
+static CYTHON_INLINE float __PYX_NAN() {
+  // Initialize NaN.  The sign is irrelevant, an exponent with all bits 1 and
+  // a nonzero mantissa means NaN.  If the first bit in the mantissa is 1, it is
+  // a quiet NaN.
+  float value;
+  memset(&value, 0xFF, sizeof(value));
+  return value;
+}
+#endif
+
 
 /////////////// UtilityFunctionPredeclarations.proto ///////////////