I'm working in an embedded system (RTXC) where I need to disable the debugger functionality which is enabled through a #define command. However, when I change the #define to undefine, compilation goes off fine, but when the linker runs, it encounters an error about a symbol not existing that belongs to the debug code (which should have been taken care of by the debugger variable not being defined). Is there any way for Make to ensure that a preprocessor variable does not get defined or stays undefined ?
The answer to your question is no, Make can't absolutely prevent a variable from being defined by, say, a #define expression in the code.
You seem to have an elusive problem. It could be a bug in your Makefiles, a misspelled directive, a bad macro (if you'll pardon the tautology) or something trivial. I'd suggest burning the forest: cut out everything until the problem stops, then see where it was hiding. If you get down to HelloWorld and the problem persists, let us know.
No. You will need to fix the bug in your code.
More specifically, there is something that is referencing the debug side of things outside of an #ifdef. Make won't be able to help you there.
Another possibility is that you have a .o or something left over from a previous build; you might want to try cleaning the build tree.
Related
I honestly can't even find anything like this anywhere on the internet, seems kind of like an obvious feature that is missing.
Basically, I'd like the compiler to check the names of every local variable and cause a build to fail if certain variable names are used. Just as an example, I'd like the build to fail if someone tries to use "x" as a variable for anything.
I get that determined folks would find a ways around it, but I'd like to see if it could be done.
I'm interested more in hearing if this can be done in Visual Studio since that's just what I use the most, but I'd be interesting in hearing about any kind of feature like this for any language / compiler if you know of one.
I'm completely stumped. I've been debugging for over a year and have only had this problem when the Build Configuration was set to Release. I have the Build Configuration set to Debug and I have checked to be sure I am attaching to the correct process and yet I still cannot see the values while stepping through the code. Has anybody else ran into this issue?
Here is a screen shot:
The value is returning, but I am unable to see the values of ANYTHING in this method or any of the other methods and I cannot figure out why.
Thank you for any hints you can give me.
============================== UPDATE ==================================
I've tried to print out the valued and this is the output I receive:
Notice though, that the value in the Variables view is correct for the result, even though I can't print it out. But the other values, like filePath should not be nil.
This is so weird.
============================== UPDATE ==================================
I put the breakpoint on the return statement and still no luck:
This time I see no value for result:
I was facing the same issue, On mouse hover and watch section for every variable it was showing nil value but while NSLog for those variables it was printing correct value.
now it's fixed. Try this
Go to Product menu > Scheme > Edit scheme or ⌘+<
In Run go to Info tab, change the build configuration to "debug".
Hope it will work.
#Lucy, ideally you shouldn't have to run in Release profile when debugging, Release is meant as an App Distribution profile with a small package size and little / no debug symbols.
But if you must debug on Release (e.g. due to Environment, data reasons), make sure you have the Optimization Level set to 'None' for Release.
You can reach the config above through:
1) Project wide settings - affects all Targets
2) Target specific setting - affects a single Target only
Don't forget to switch this back before App Store distribution. Lower Optimization will generate a larger ipk increasing your users' download time - also the potential dSYM generated.
Background
For context, Debug, Adhoc or Release profiles are purely to id different build configurations that XCode ships with. XCode starts projects with a Debug profile with no Optimization (and various other predefined config related to development & debugging), so symbol loading by the interpreter is possible - you're free to tweak this however you wish.
Theoretically able to establish a Release build profile that's identical to Debug.
I do see part of your problem. notice how self is nil?
That means you are in a method call for a de-allocated object. Turn on NSZombies to debug.
see this SO answer for how to enable NSZombie
Given that it is legal to send messages to nil in objective-C, I would suspect that the object is being deallocated as a side effect of calling doesLicenseFileExist, or by another thread.
You may find it helpful to put a breakpoint in IDLicenseCommands -dealloc method.
I had this problem, and turned "Link-Time Optimization" from "Incremental" to "No" and it resolved the debugging issue.
Is there a lint for Elixir (like for Javascript) which checks that every function has a type specification?
There is an Erlang compiler switch, +warn_missing_spec, which does this, but I'm having trouble getting it to work with Elixir at the moment, I think there is a bug with it's parsing of the ELIXIR_ERL_OPTS environment variable which is converting +warn_missing_spec into -warn_missing_spec which isn't a valid compiler option. I'm going to open an issue on the tracker, but thought you might like to know that this does indeed exist.
EDIT: As José mentioned below, the correct flag is ERL_COMPILER_OPTIONS. You can enable the missing spec warning during compilation by doing the following:
ERL_COMPILER_OPTIONS="warn_missing_spec" mix compile
Keep in mind you may get superfluous warnings from Elixir itself, for functions like __MODULE__. It should still be useful though. One last thing to note, I discovered this morning that there is a problem using this flag with mix compile, and that it's currently only warning about mix.exs. This is being fixed, and may even be fixed by the time you see this, but it's something to be aware of.
Here are my two lines of code:
NSString *frontFilePath = [[NSBundle mainBundle] pathForResource:[self.bookendFileNames objectAtIndex:self.randomIndex] ofType:#"caf"];
NSLog(#"frontFilePath = %#", frontFilePath );
I put a break point on the second line and when there, I try to print it:
(lldb) po frontFilePath
But I get the following error:
error: variable not available
I'm confused because if I step over the NSLog statement, the variable does indeed print to the console.
For what it's worth, I'm trying to debug the first line since sometimes it returns NULL, tho I can't, as of now, figure out why.
This is an artifact of debugging optimized code. When the compiler's optimization is enabled in your build settings, it moves variables between memory and registers as it decides is best. At the point where you're examining the variable in lldb, it may not exist in registers or memory at all -- even though it looks like it should still be available for display.
It's possible it is a shortcoming of the debug information output by the compiler. Sometimes the compiler will copy a variable into a register for its use and only list that register location in the debug information. Later the register is repurposed for other uses; value is still present on the stack but the compiler hasn't told the debugger that the value can be found there.
The only way to really tell whether it's insufficient debug info or if the value genuinely doesn't exist at that particular instruction is to examine the assembly code by hand. As soon as you turn on optimization with the compiler, the source code becomes a weak view into what's actually being executed in any particular order.
Instead of wandering too far into the wacky world of optimized code debugging, I strongly recommend turning off optimization (Optimization Level in your Build Settings) for your build and debugging it that way, if at all possible. If you do need to debug your app with optimization, make sure you're building with the latest Apple LLVM compiler supported by your Xcode -- there is always work being done to improve optimized code debugging and you want to avail yourself of the most up to date tools you can.
The "Address Sanitizer" in the diagnostics seems to make the values of variables unavailable, too.
Schemes > Run > Diagnostics > Address Sanitizer
In Swift, possibly starting with Xcode 9 and still an issue in Xcode 10, this could even come up when code optimization is turned off in the build settings. As #carlos_ms has pointed out here, a temporary solution is to define the variable as mutable, i.e.
Turn
let foo = Bar().string
into
var foo = Bar().string
in order to cause optimization to skip on this variable. Note that this might not work in all instances.
In this case, a good ol' debugPrint() might help you out.
I know that I can ignore compiler warnings with -w on a given file in Xcode.
I would like to similarly ignore analyze warnings on a given file (JSONKit.m in this case, which has two potential leaks). I trust that the developer of that library knows what they're doing, and I don't want to maintain a fork of it. Not to mention that I have no clue what's going on in there anyway.
Any ideas?
Don't trust the developer. Figure out why the potential leaks exist and fix them (ideally, sending a patch back to the developer).
If you want to take the lazy way out (j/k ;), you can add code to fix the problem under the analyzer only using:
#ifdef __clang_analyzer__
... release the offending variable here ...
#endif
I prefer this solution to whole-file-disabling because it both exactly identifies the problem area with an easily searchable identifier and it allows the rest of the file to be vetted by the constantly improving analyzer.