minimize changes to node_api.h

Author: vmoroz

src/node_api.h

@@ -31,7 +31,6 @@ struct uv_loop_s;  // Forward declaration.
 typedef napi_value(NAPI_CDECL* napi_addon_register_func)(napi_env env,
                                                          napi_value exports);
 
-// Used by deprecated registration method napi_module_register.
 typedef struct napi_module {
   int nm_version;
   unsigned int nm_flags;
@@ -44,16 +43,68 @@ typedef struct napi_module {
 
 #define NAPI_MODULE_VERSION 1
 
+#if defined(_MSC_VER)
+#if defined(__cplusplus)
+#define NAPI_C_CTOR(fn)                                                        \
+  static void NAPI_CDECL fn(void);                                             \
+  namespace {                                                                  \
+  struct fn##_ {                                                               \
+    fn##_() { fn(); }                                                          \
+  } fn##_v_;                                                                   \
+  }                                                                            \
+  static void NAPI_CDECL fn(void)
+#else  // !defined(__cplusplus)
+#pragma section(".CRT$XCU", read)
+// The NAPI_C_CTOR macro defines a function fn that is called during CRT
+// initialization.
+// C does not support dynamic initialization of static variables and this code
+// simulates C++ behavior. Exporting the function pointer prevents it from being
+// optimized. See for details:
+// https://docs.microsoft.com/en-us/cpp/c-runtime-library/crt-initialization?view=msvc-170
+#define NAPI_C_CTOR(fn)                                                        \
+  static void NAPI_CDECL fn(void);                                             \
+  __declspec(dllexport, allocate(".CRT$XCU")) void(NAPI_CDECL * fn##_)(void) = \
+      fn;                                                                      \
+  static void NAPI_CDECL fn(void)
+#endif  // defined(__cplusplus)
+#else
+#define NAPI_C_CTOR(fn)                                                        \
+  static void fn(void) __attribute__((constructor));                           \
+  static void fn(void)
+#endif
+
+#define NAPI_MODULE_X(modname, regfunc, priv, flags)                           \
+  EXTERN_C_START                                                               \
+  static napi_module _module = {                                               \
+      NAPI_MODULE_VERSION,                                                     \
+      flags,                                                                   \
+      __FILE__,                                                                \
+      regfunc,                                                                 \
+      #modname,                                                                \
+      priv,                                                                    \
+      {0},                                                                     \
+  };                                                                           \
+  NAPI_C_CTOR(_register_##modname) { napi_module_register(&_module); }         \
+  EXTERN_C_END
+
 #define NAPI_MODULE_INITIALIZER_X(base, version)                               \
   NAPI_MODULE_INITIALIZER_X_HELPER(base, version)
 #define NAPI_MODULE_INITIALIZER_X_HELPER(base, version) base##version
 
 #ifdef __wasm32__
-#define NAPI_MODULE_INITIALIZER_BASE napi_register_wasm_v
-#else
-#define NAPI_MODULE_INITIALIZER_BASE napi_register_module_v
+#define NAPI_WASM_INITIALIZER                                                  \
+  NAPI_MODULE_INITIALIZER_X(napi_register_wasm_v, NAPI_MODULE_VERSION)
+#define NAPI_MODULE(modname, regfunc)                                          \
+  EXTERN_C_START                                                               \
+  NAPI_MODULE_EXPORT napi_value NAPI_WASM_INITIALIZER(napi_env env,            \
+                                                      napi_value exports) {    \
+    return regfunc(env, exports);                                              \
+  }                                                                            \
+  EXTERN_C_END
 #endif
 
+#define NAPI_MODULE_INITIALIZER_BASE napi_register_module_v
+
 #define NAPI_MODULE_INITIALIZER                                                \
   NAPI_MODULE_INITIALIZER_X(NAPI_MODULE_INITIALIZER_BASE, NAPI_MODULE_VERSION)
 
@@ -64,13 +115,13 @@ typedef struct napi_module {
   EXTERN_C_END                                                                 \
   napi_value NAPI_MODULE_INITIALIZER(napi_env env, napi_value exports)
 
+#ifndef __wasm32__
 #define NAPI_MODULE(modname, regfunc)                                          \
   NAPI_MODULE_INIT() { return regfunc(env, exports); }
+#endif
 
 EXTERN_C_START
 
-// Deprecated. Replaced by symbol-based registration defined by NAPI_MODULE
-// and NAPI_MODULE_INIT macros.
 NAPI_EXTERN void NAPI_CDECL napi_module_register(napi_module* mod);
 
 NAPI_EXTERN NAPI_NO_RETURN void NAPI_CDECL