Removing Logs when releasing iOS app

Question

Currently I am building two apps for my project one in release & another in debug (the only thing that changes are provisioning profiles used to sign and the endpoints) . Because of some policies, I shouldn't be creating ipa files locally. So I use maven to build these two versions (release & debug), based on a script. Because of the same policies, output should be complete removed from the application (NSLog, printf...). I am aware of the preprocessor macros, but I don't want to rely on them, since someone (without knowing) might change them and jeopardise what I want to achieve. So what I want is:

1. Be able to logout anything I want when I am using my simulator or when I run directly on a real device
2. When I use maven to build my applications, it will make sure the NSLogs are stripped or disabled.

Maven relies on what's in a remote repository to actually make the build, so if there is a way of disabling this logs during the remote repo commit, it's a solution as well..

Answer 1

It's an interesting request, but feasible if you're willing to accept a bit of function-call overhead for each log that gets skipped. There is a nice feature inside of the EtPanKit framework that checks if the files that are trying to call the log function match an array of pre-defined classes in your Info.plist file. In addition to being a great debug filter, all you'd have to do at Release time is remove all the keys from the plist or specify a different one in your Release build with no values associated with the LEPLogEnabledFilenames key.

In the interest of preventing link-rot, here's the function itself and the associated macros that make it a bit prettier to call:

#define LEPLogStack(...) LEPLogInternal(__FILE__, __LINE__, 1, __VA_ARGS__)
#define LEPLog(...) LEPLogInternal(__FILE__, __LINE__, 0, __VA_ARGS__)

#import <Foundation/Foundation.h>
#import <libgen.h>
#import <time.h>
#import <sys/time.h>
#include <execinfo.h>
#include <pthread.h>

static NSSet * enabledFilesSet = nil;
static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;

void LEPLogInternal(const char * filename, unsigned int line, int dumpStack, NSString * format, ...)
{
    va_list argp;
    NSString * str;
    NSAutoreleasePool * pool;
    char * filenameCopy;
    char * lastPathComponent;
    struct timeval tv;
    struct tm tm_value;
    //NSDictionary * enabledFilenames;

    pool = [[NSAutoreleasePool alloc] init];

    pthread_mutex_lock(&lock);
    if (enabledFilesSet == nil) {
        enabledFilesSet = [[NSSet alloc] initWithArray:[[NSUserDefaults standardUserDefaults] arrayForKey:LEPLogEnabledFilenames]];
    }
    pthread_mutex_unlock(&lock);

    NSString * fn;
    fn = [[NSFileManager defaultManager] stringWithFileSystemRepresentation:filename length:strlen(filename)];
    fn = [fn lastPathComponent];
    if (![enabledFilesSet containsObject:fn]) {
        [pool release];
        return;
    }

    va_start(argp, format);
    str = [[NSString alloc] initWithFormat:format arguments:argp];
    va_end(argp);

    NSString * outputFileName = [[NSUserDefaults standardUserDefaults] stringForKey:LEPLogOutputFilename];
    static FILE * outputfileStream = NULL;
    if ( ( NULL == outputfileStream ) && outputFileName )
    {
        outputfileStream = fopen( [outputFileName UTF8String], "w+" );
    }

    if ( NULL == outputfileStream )
        outputfileStream = stderr;

    gettimeofday(&tv, NULL);
    localtime_r(&tv.tv_sec, &tm_value);
    fprintf(outputfileStream, "%04u-%02u-%02u %02u:%02u:%02u.%03u ", tm_value.tm_year + 1900, tm_value.tm_mon + 1, tm_value.tm_mday, tm_value.tm_hour, tm_value.tm_min, tm_value.tm_sec, tv.tv_usec / 1000);
    //fprintf(stderr, "%10s ", [[[NSDate date] description] UTF8String]);
    fprintf(outputfileStream, "[%s:%u] ", [[[NSProcessInfo processInfo] processName] UTF8String], [[NSProcessInfo processInfo] processIdentifier]);
    filenameCopy = strdup(filename);
    lastPathComponent = basename(filenameCopy);
    fprintf(outputfileStream, "(%s:%u) ", lastPathComponent, line);
    free(filenameCopy);
    fprintf(outputfileStream, "%s\n", [str UTF8String]);
    [str release];

    if (dumpStack) {
        void * frame[128];
        int frameCount;
        int i;

        frameCount = backtrace(frame, 128);
        for(i = 0 ; i < frameCount ; i ++) {
            fprintf(outputfileStream, "  %p\n", frame[i]);
        }
    }

    if ( outputFileName )
    {
        fflush(outputfileStream);
    }

    [pool release];
}