need help to find a way to replace c macro

[ryuukk_]

Try this great tool by denis korpel 
https://dkorpel.github.io/ctod/

I've been using it every so often to port C stuff, it's been very 
helpful

```D
@nogc nothrow:
extern(C): __gshared:
union JSCFunctionType {
     JSCFunction* generic;
     JSValue function(JSContext* ctx, JSValueConst this_val, int 
argc, JSValueConst* argv, int magic) generic_magic;
     JSCFunction* constructor;
     JSValue function(JSContext* ctx, JSValueConst new_target, int 
argc, JSValueConst* argv, int magic) constructor_magic;
     JSCFunction* constructor_or_func;
     double function(double) f_f;
     double function(double, double) f_f_f;
     JSValue function(JSContext* ctx, JSValueConst this_val) 
getter;
     JSValue function(JSContext* ctx, JSValueConst this_val, 
JSValueConst val) setter;
     JSValue function(JSContext* ctx, JSValueConst this_val, int 
magic) getter_magic;
     JSValue function(JSContext* ctx, JSValueConst this_val, 
JSValueConst val, int magic) setter_magic;
     JSValue function(JSContext* ctx, JSValueConst this_val, int 
argc, JSValueConst* argv, int* pdone, int magic) iterator_next;
}

struct JSCFunctionListEntry {
     const(char)* name;
     ubyte prop_flags;
     ubyte def_type;
     short magic;
     union _U {
         struct _Func {
             ubyte length; /* XXX: should move outside union */
             ubyte cproto; /* XXX: should move outside union */
             JSCFunctionType cfunc;
         }_Func func;
         struct _Getset {
             JSCFunctionType get;
             JSCFunctionType set;
         }_Getset getset;
         struct _Alias_ {
             const(char)* name;
             int base;
         }_Alias_ alias_;
         struct _Prop_list {
             const(JSCFunctionListEntry)* tab;
             int len;
         }_Prop_list prop_list;
         const(char)* str;
         int i32;
         long i64;
         double f64;
     }_U u;
}

enum string JS_CFUNC_DEF(string name, string length, string 
func1) = `{ ` ~ name ~ `, JS_PROP_WRITABLE | 
JS_PROP_CONFIGURABLE, JS_DEF_CFUNC, 0, .u = { .func = { ` ~ 
length ~ `, JS_CFUNC_generic, { .generic = ` ~ func1 ~ ` } `;
enum string JS_CFUNC_MAGIC_DEF(string name, string length, string 
func1, string magic) = `{ ` ~ name ~ `, JS_PROP_WRITABLE | 
JS_PROP_CONFIGURABLE, JS_DEF_CFUNC, ` ~ magic ~ `, .u = { .func = 
{ ` ~ length ~ `, JS_CFUNC_generic_magic, { .generic_magic = ` ~ 
func1 ~ ` } `;
enum string JS_CFUNC_SPECIAL_DEF(string name, string length, 
string cproto, string func1) = `{ name, JS_PROP_WRITABLE | 
JS_PROP_CONFIGURABLE, JS_DEF_CFUNC, 0, .u = { .func = { length, 
JS_CFUNC_ ## cproto, { .cproto = func1 } } } }`;
enum string JS_ITERATOR_NEXT_DEF(string name, string length, 
string func1, string magic) = `{ ` ~ name ~ `, JS_PROP_WRITABLE | 
JS_PROP_CONFIGURABLE, JS_DEF_CFUNC, ` ~ magic ~ `, .u = { .func = 
{ ` ~ length ~ `, JS_CFUNC_iterator_next, { .iterator_next = ` ~ 
func1 ~ ` } `;
enum string JS_CGETSET_DEF(string name, string fgetter, string 
fsetter) = `{ ` ~ name ~ `, JS_PROP_CONFIGURABLE, JS_DEF_CGETSET, 
0, .u = { .getset = { .get = { .getter = ` ~ fgetter ~ ` }, .set 
= { .setter = ` ~ fsetter ~ ` } `;
enum string JS_CGETSET_MAGIC_DEF(string name, string fgetter, 
string fsetter, string magic) = `{ ` ~ name ~ `, 
JS_PROP_CONFIGURABLE, JS_DEF_CGETSET_MAGIC, ` ~ magic ~ `, .u = { 
.getset = { .get = { .getter_magic = ` ~ fgetter ~ ` }, .set = { 
.setter_magic = ` ~ fsetter ~ ` } `;



private const(JSCFunctionListEntry)[20] js_std_funcs = [
     mixin(JS_CFUNC_DEF!(`"exit"`, `1`, `js_std_exit` )),
     mixin(JS_CFUNC_DEF!(`"gc"`, `0`, `js_std_gc` )),
     mixin(JS_CFUNC_DEF!(`"evalScript"`, `1`, `js_evalScript` )),
     mixin(JS_CFUNC_DEF!(`"loadScript"`, `1`, `js_loadScript` )),
     mixin(JS_CFUNC_DEF!(`"getenv"`, `1`, `js_std_getenv` )),
     mixin(JS_CFUNC_DEF!(`"setenv"`, `1`, `js_std_setenv` )),
     mixin(JS_CFUNC_DEF!(`"unsetenv"`, `1`, `js_std_unsetenv` )),
     mixin(JS_CFUNC_DEF!(`"getenviron"`, `1`, `js_std_getenviron` 
)),
     mixin(JS_CFUNC_DEF!(`"urlGet"`, `1`, `js_std_urlGet` )),
     mixin(JS_CFUNC_DEF!(`"loadFile"`, `1`, `js_std_loadFile` )),
     mixin(JS_CFUNC_DEF!(`"strerror"`, `1`, `js_std_strerror` )),
     mixin(JS_CFUNC_DEF!(`"parseExtJSON"`, `1`, 
`js_std_parseExtJSON` )),

     /* FILE I/O */
     mixin(JS_CFUNC_DEF!(`"open"`, `2`, `js_std_open` )),
     mixin(JS_CFUNC_DEF!(`"popen"`, `2`, `js_std_popen` )),
     mixin(JS_CFUNC_DEF!(`"fdopen"`, `2`, `js_std_fdopen` )),
     mixin(JS_CFUNC_DEF!(`"tmpfile"`, `0`, `js_std_tmpfile` )),
     mixin(JS_CFUNC_MAGIC_DEF!(`"puts"`, `1`, `js_std_file_puts`, 
`0` )),
     mixin(JS_CFUNC_DEF!(`"printf"`, `1`, `js_std_printf` )),
     mixin(JS_CFUNC_DEF!(`"sprintf"`, `1`, `js_std_sprintf` )),
];
```