Utilities.m

//
//  Utilities.m
//  RubyNative
//
//  Created by John Holdsworth on 26/09/2015.
//  Copyright © 2015 John Holdsworth. All rights reserved.
//
//  $Id: //depot/SwiftRuby/Utilities.m#21 $
//
//  Repo: https://github.com/RubyNative/SwiftRuby
//

#import "Utilities.h"

#import <objc/runtime.h>
#import <dlfcn.h>
#import <spawn.h>

// Thanks to Jay Freeman's https://www.youtube.com/watch?v=Ii-02vhsdVk

struct _in_objc_class {

    Class meta, supr;
    void *cache, *vtable;
    struct _in_objc_ronly *internal;

    // data new to swift
    int f1, f2; // added for 1.0 Beta5
    int size, tos, mdsize, eight;

    struct _swift_data3 {
//        unsigned long flags;
//        const char *className;
        int className;
        int fieldcount, flags2;
        int ivarNames;
        int get_field_data;
//        const char *ivarNames;
//        struct _swift_field **(*get_field_data)();
    } *swiftData;

    IMP dispatch[1];
};

// Swift3 pointers to some metadata are relative
static const char *swift3Relative(void *ptrPtr) {
    intptr_t offset = *(int *)ptrPtr;
    return offset < 0 ? (const char *)((intptr_t)ptrPtr + offset) : (const char *)offset;
}

NSArray<NSString *> *instanceVariablesForClass(Class cls, NSMutableArray<NSString *> *ivarNames) {
    assert(0 && "This code is obsolete");
    Class superCls = class_getSuperclass(cls);
    if (superCls)
        instanceVariablesForClass(superCls, ivarNames);

    struct _in_objc_class *swiftClass = (__bridge struct _in_objc_class *)cls;

    if ((uintptr_t)swiftClass->internal & 0x1) {
        struct _swift_data3 *swiftData = (struct _swift_data3 *)swift3Relative(&swiftClass->swiftData);
        const char *nameptr = swift3Relative(&swiftData->ivarNames);

        for (int f = 0 ; f < swiftData->fieldcount ; f++) {
            [ivarNames addObject:[NSString stringWithFormat:@"%@.%@", NSStringFromClass(cls),
                                  [NSString stringWithUTF8String:nameptr]]];
            nameptr += strlen(nameptr) + 1;
        }
    }
    else {
        unsigned ic;
        Ivar *ivars = class_copyIvarList(cls, &ic);
        for (unsigned i=0 ; i<ic ; i++)
            [ivarNames addObject:[NSString stringWithFormat:@"%@.%@", NSStringFromClass(cls),
                                  [NSString stringWithUTF8String:ivar_getName(ivars[i])]]];
    }

    return ivarNames;
}

NSArray<NSString *> *methodSymbolsForClass(Class cls, NSMutableArray<NSString *> *syms) {
    assert(0 && "This code is obsolete");

    struct _in_objc_class *swiftClass = (__bridge struct _in_objc_class *)cls;

    IMP *sym_start = swiftClass->dispatch,
        *sym_end = (IMP *)((char *)swiftClass + swiftClass->mdsize - 2*sizeof(IMP));

    Dl_info info;
    for (IMP *sym_ptr = sym_start ; sym_ptr < sym_end ; sym_ptr++)
        if (dladdr(*sym_ptr, &info) && info.dli_sname)
            [syms addObject:[NSString stringWithUTF8String:info.dli_sname]];

    return syms;
}

static NSString *kLastExceptionKey = @"SwiftRubyException";
NSString *kCatchLevels = @"SwiftRubyCatchLevels";

void _try(void (^tryBlock)(void)) {
    NSMutableDictionary *threadDictionary = [NSThread currentThread].threadDictionary;
    int catchLevels = [threadDictionary[kCatchLevels] intValue];
    threadDictionary[kCatchLevels] = @(catchLevels+1);
    threadDictionary[kLastExceptionKey]  = nil;
    @try {
        tryBlock();
    }
    @catch (NSException *e) {
        threadDictionary[kLastExceptionKey] = e;
    }
    threadDictionary[kCatchLevels] = @(catchLevels);
}

void _catch(void (^catchBlock)(NSException *e )) {
    NSMutableDictionary *threadDictionary = [NSThread currentThread].threadDictionary;
    NSException *e = threadDictionary[kLastExceptionKey];
    if (e) {
        threadDictionary[kLastExceptionKey]  = nil;
        catchBlock(e);
    }
}

void _throw(NSException *e) {
    if ([[NSThread currentThread].threadDictionary[kCatchLevels] intValue] > 0)
        @throw e;
    else {
        fputs([[NSString stringWithFormat:@"SwiftRuby: Uncaught Exception: name: %@, reason: %@, userInfo: %@\n",
                e.name, e.reason, e.userInfo] UTF8String], stderr);
        abort();
    }
}

void execArgv(NSString *executable, NSArray<NSString *> *arguments) {
    const char **argv = calloc(arguments.count+1, sizeof *argv);
    for (NSUInteger i=0 ; i<arguments.count ; i++)
        argv[i] = [arguments[i] UTF8String];
    execv([executable UTF8String], (char * const *)argv);
    NSLog(@"execArgv: execv(%@, ...) failed: %s", executable, strerror(errno));
}

pid_t spawnArgv(NSString *executable, NSArray<NSString *> *arguments) {
    const char **argv = calloc(arguments.count+1, sizeof *argv);
    for (NSUInteger i=0 ; i<arguments.count ; i++)
        argv[i] = [arguments[i] UTF8String];
    pid_t pid = 0;
    if (posix_spawnp(&pid, [executable UTF8String], NULL, NULL, (char * const *)argv, NULL) != 0)
        NSLog(@"spawnArgv: posix_spawnp(%@, ...) failed: %s", executable, strerror(errno));
    free(argv);
    return pid;
}

int fcntl3(int fildes, int cmd, int flags) {
    return fcntl(fildes, cmd, flags);
}

int _system(const char *command) {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
    return system(command);
#pragma clang diagnostic pop
}

FILE *_popen(const char *command, const char *perm) {
    return popen(command, perm);
}

int _pclose(FILE *fp) {
    return pclose(fp);
}