I have an iOS project which has a static library and in the library there is a encrypt method and in the method it refers a lot of system encrypt method about AES encryption. When I build the static library with release,it returned the correct data.But when I build with debug mode,it returns nil.
What's the differences between the two modes？
The same source code can build out different binary files that works differently?
Help me,thanks beforehand. This is where I choose the two modes.
The main difference is the level of compiler optimization. Select the project target and look at the Build Settings and compare Debug to Release.
One potential reason for the crash is that the code has some memory usage errors that by coincidence do not cause a crash with code optimization but do with no optimization. Or there are some other configuration difference. See the comment by #iDev.
A starting point is to fix all warnings, both compiler and Analyzer. The examine the crash log to understand the crash. If you need help with that add a crash report to your question.
Related
Is there any way to completely remove logs from a final release build of an application written in Swift? By completely I mean that if I open the compiled binary file in a text/hex editor there should be no logged strings in it and if someone disassembles the binary file also he should not see any logged strings in a disassembler.
I know that I can disable writing the logs to the console in release build with #if DEBUG for example with something like this:
func log(_ message: String) {
#if DEBUG
print(message)
#endif
}
But when using this approach logged strings are still visible in compiled binary (and could for example help someone in analysing disassembled code of the application). They are just not printed on the console and that is not acceptable for me. I want to remove them completely from compiled binary. In Objective-C we could use preprocesor macros to achieve that but they are not available in Swift. I could put #if DEBUG before each occurrence of log/print function in the code and that would work but obviously this is not a great solution as it would require to add this #if DEBUG in hundreds of places. Alternatively I could just do find and replace to comment all print/log calls before building a release build but this is also not a great solution as I would need to comment and uncomment those logs each time I build the release version. Is there any better way to achieve that?
You could try using the the Logger framework provided by Apple
It is more performant that print statements, and you have more control over what is logged - for developing and debugging you can use the debug log level. There are other logging levels that generate messages during run time with privacy options.
There is a WWDC Video which you may find useful to introduce you to this.
I am trying to integrate unity to iOS application. I have followed this tutorial http://www.agnosticdev.com/blog-entry/swift/integrating-unity-and-vuforia-ios-swift-project
Now after integrating when i start my app it crashes and show this error on console : was compiled with optimization - stepping may behave oddly; variables may not be available.
Crash :
I have tried googling this and found these links :
APPNAME was compiled with optimization - stepping may behave oddly; variables may not be available
'Project Name' was compiled with optimization - stepping may behave oddly; variables may not be available
Xcode target compiled with optimization
Xcode: Cannot set optimization level for debug
and nothing changed.
I have changed optimization level of both project and pod.
I have also added this line to pod file : project 'MyProject', 'Debug - local'=>:debug, 'Debug - staging'=>:debug, 'Debug - PRODUCTION'=>:debug ( before target 'projectname' do)
Also I have unchecked Strip Engine Code in unity.
What can i do to overcome this error ?
Any help would be appreciated, thanks.
The code you're debugging is IL2CPP code, which is likely in a library prebuilt with optimizations (probably in libiPhone-lib.a). Your build settings only effect the code being compiled now in your xcode project, so they wouldn't effect a prebuilt lib. To get rid of the warning, you will need to rebuild that library, and you will need Unity source code to do that.
More importantly, it's not the cause of the crash. It's just telling you that it's going to be harder to find the source of the crash.
It looks like it's calling a function called LoadMetadataFile and crashing when accessing the return. You can probably set a breakpoint on that function call and see what's going in and out of it to find the next debugging step (the bl instructions 5 lines above the highlighted crashing line).
Here are some documents that might help you:
Apples calling convention docs:
https://developer.apple.com/library/content/documentation/Xcode/Conceptual/iPhoneOSABIReference/Articles/ARM64FunctionCallingConventions.html
Arm instruction reference (opened to the crashing instruction): http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0802a/LDRSW_imm.html
I had the same issue and I solve it adding to Apple LLVM - Custom Compiler FLags:
Other C Flags: -DRUNTIME_IL2CPP=1
I have several assert(condition, "message") statements in my project.
They are used to check invariant conditions during development. I thought they would be ignored in production/release build (as stated in this answer). They are not. Instead they cause crashes during TestFlight testing. When I comment asserts the app does not crash. Something usually gets wrong a bit but it does not crash.
Can it be something with my build settings?
All my archive schemes use release configuration:
The asserts are in Cocoa Touch Framework project, that is used from custom keyboard extension.
All the targets in all projects (Cocoa Touch Framework, and the main project with keyboard extension target) have these Build Settings:
Enable Foundation Assertions
Debug YES
Release NO
Disable Safety Checks NO
What's wrong?
EDIT:
Sulthan's answer shows how to disable asserts globally for both debug and relase builds. That is not what I need. I want it to work as expected - asserts should be enabled in debug but disabled in release builds.
By default it works that way - and it also works that way in my main project. But it does not work for asserts located in Framework project that is linked from that main project (details in this question). Why? How to fix it?
The options you have tried:
Enable Foundation Assertions is in the preprocessing section (Macros). Swift is not preprocessed and does not use macros. This option disables NSAssert, NSParameterAssert and similar macros commonly used in Objective-C.
Disable Safety Checks is a performance option:
By default, the standard library guarantees memory safety. Many functions and methods document the requirements that must be satisfied by the caller, such as an array index being valid; memory safety is guaranteed even if a requirement is violated. However, violating a requirement can trigger a runtime error. APIs that include the word “unsafe” in their name let you explicitly disable safety checks in places where you need the additional performance. It’s your responsibility to verify the memory safety of code that uses unsafe APIs. Memory safety is also not guaranteed if there is a race condition in multithreaded code.
(Swift Library Reference)
You should probably try my answer here
(use -assert-config Release in Other Swift Flags).
Or just keep the asserts in production builds. Every failing assert is a bug and in general it's better to know about a bug as soon as possible.
I'm having a problem with breakpoints in the source code of a specific library / framework (new to Xcode - i'm not sure what the correct term is) in a fairly large iOS project. I have all the code for this library. Breakpoints are working fine everywhere else, but in this one specific library, all breakpoints are ignored.
I can put a breakpoint in a function called from within one of those source files, and it will trigger, but then the callstack shows "__lldb_unnamed_function" for the location in the file i'm interested in, as if the symbols have been stripped.
I have the following settings for the library in question
Generate Debug Symbols = YES
Strip Debug Symbols During Copy = NO
Strip Linked Product = NO
Dead Code Stripping = NO
I have been using a lot of #ifdefs to test alternate implementations of a few functions so i thought some stuff might be getting marked as dead code by accident (hence that last setting). I already tried clean/rebuild. I tried completely removing the app from the target iPhone. I tried deleting intermediate file folder under
/Library/Developer/Xcode/DerivedData
The code is definitely executing because all my NSLog calls show up properly.
I don't have much experience with Xcode so i'm hoping i'm just missing something simple
Thanks
Some part of your build process must be stripping this binary. If you were generating an unstripped binary with no debug information, then you would see full symbol names in backtraces and the like, you just wouldn't have debug information for them.
The only good way to figure out who is doing this is to look at the full build log in Xcode, and expand each of the stages and grub through all the build stages to figure out who is doing this. You expand the stages by hovering over each build line on the RHS and you'll get a disclosure dingus that looks like a bunch of lines on a page; click that to see the real commands.
Another way to finesse this may be to build the dSYM for this framework (by setting the Debug Format to "DWARF + dSYM".) That should get made before anything gets stripped, so unless whoever is stripping this is being awfully clever this should preserve the debug information.
I'm trying to use the OpenGL ES Analyzer for my iPad application and I can't get it to show me any symbols from my code in the extended detail pane's stack trace. I see the names of UIKit and UIApplication and other Apple supplied frameworks in the stack trace, but the portion of the stack trace that represents calls into my code just shows up as instruction pointer values, and there are no symbols whatever.
When I run the same app in Xcode 4 I can debug into my code without problem, all symbols are there, etc. So I believe the application is compiled correctly in this regard.
Do others out there have this problem? The information this analyzer is collecting would be extremely useful if I could see where it my code these calls are being made...
Any pointers / workaround very much appreciated.
-Eric
Well, figured this out myself eventually, so just for completeness and for anyone else who runs into this:
It is necessary to have dSYM debugger output, i.e. "DWARD with dSYM file" in the "Debug Information Format" setting in the project.
I had changed this to be just DWARF as creating the dSYM was taking a long time each build cycle.