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@mayoff
mayoff / !README.md
Last active August 14, 2023 15:09
Debugging Objective-C blocks in lldb

The attached lldb command pblock command lets you peek inside an Objective-C block. It tries to tell you where to find the source code for the block, and the values captured by the block when it was created.

Consider this example program:

#import <Foundation/Foundation.h>

@interface Foo: NSObject
@end

@implementation Foo

@iandees
iandees / dlib_plus_osm.md
Last active May 30, 2018 19:07
Detecting Road Signs in Mapillary Images with dlib C++

image

I've been interested in computer vision for a long time, but I haven't had any free time to make any progress until this holiday season. Over Christmas and the New Years I experimented with various methodologies in OpenCV to detect road signs and other objects of interest to OpenStreetMap. After some failed experiments with thresholding and feature detection, the excellent /r/computervision suggested using the dlib C++ module because it has more consistently-good documentation and the pre-built tools are faster.

After a day or two figuring out how to compile the examples, I finally made some progress:

Compiling dlib C++ on a Mac with Homebrew

  1. Clone dlib from Github to your local machine:
BOOL PSPDFSystemFunctionOverriddenInCategory(Class theClass, SEL selector, NSString *__autoreleasing* categoryName) {
NSCParameterAssert(theClass);
NSCParameterAssert(selector);
Dl_info info;
if (dladdr(class_getMethodImplementation(theClass, selector), &info)) {
// /System/Library/Frameworks is a common denominator, some methods are in /usr/lib/libobjc.A.dylib
// Custom app is in /private/var/mobile/Containers/Bundle/Application/<UID>/PSPDFCatalog.app/PSPDFCatalog
if (!strstr(info.dli_fname, "/System/Library") && !strstr(info.dli_fname, "/usr/lib")) {
if (categoryName) *categoryName = @(info.dli_sname);