Find Unused Headers

main.m

//
//  main.m
//  Unsused Import Finder
//
//  Created by Mojtaba Cazi on 6/27/17.
//  Copyright © 2017 CaziSoft, LLC. All rights reserved.
//

#import <Foundation/Foundation.h>

NSString * fileNameFromImport(NSString *line) {
    if (![line hasPrefix:@"#import"]) {
        return nil;
    }
    NSString *header = [[line componentsSeparatedByString:@"/"] lastObject];
    header = [[header componentsSeparatedByString:@"."] firstObject];
    header = [[header componentsSeparatedByString:@"+"] firstObject];
    header = [[header componentsSeparatedByString:@"\""] lastObject];
    header = [[header componentsSeparatedByString:@"<"] lastObject];
    return header;
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSDate *start = [NSDate date];
        
        __strong NSArray **prints = (__strong NSArray **)calloc(argc, sizeof(NSArray *));
        
        dispatch_apply(argc - 1, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^(size_t i) {
            NSString *path = [NSString stringWithUTF8String:argv[i + 1]];
            NSData *fileData = [[NSData alloc] initWithContentsOfFile:path];
            NSString *fileContents = [[NSString alloc] initWithData:fileData encoding:NSUTF8StringEncoding];
            
            __block NSUInteger charCount = 0;
            [fileContents enumerateLinesUsingBlock:^(NSString * _Nonnull line, BOOL * _Nonnull stop) {
                if (!line.length) {
                    return;
                }
                unichar firstChar = [line characterAtIndex:0];
                if (firstChar != '#' && firstChar != '/') {
                    *stop = YES;
                } else {
                    charCount += line.length + 1; // +1 \n
                }
            }];
            
            NSString *importLines = [fileContents substringWithRange:(NSRange){0, charCount}];
            const char *nonImportCString = [fileContents substringWithRange:(NSRange){charCount, fileContents.length - charCount}].UTF8String;
            
            NSMutableArray *importNames = [NSMutableArray arrayWithCapacity:100];
            [importLines enumerateLinesUsingBlock:^(NSString * _Nonnull line, BOOL * _Nonnull stop) {
                NSString *importName = fileNameFromImport(line);
                if (importName.length && strstr(nonImportCString, importName.UTF8String) == NULL) {
                    [importNames addObject:importName];
                }
            }];
            
            if (importNames.count) {
                NSMutableArray *internalArray = [NSMutableArray arrayWithArray:importNames];
                [internalArray insertObject:[@"Potential unused import found in: " stringByAppendingString:path] atIndex:0];
                prints[i] = internalArray;
            }
        }); // dispatch_apply
        
        NSDate *end = [NSDate date];
        
        for (int i = 0; i < argc; i++) {
            NSArray *lines = prints[i];
            for (NSString *string in lines) {
                printf("%s\n", string.UTF8String);
            }
            if (lines.count) {
                printf("\n");
            }
        }
        
        printf("Elapsed Time: %.2fms\nProcessed %d files\n", [end timeIntervalSinceDate:start] * 1000, argc);
    }
    return 0;
}

// find .  -name "*.m" | xargs ./uif