I got an error like below when building the application. However, I don't know the actual size as it doesn't occur with some code optimization settings.
ld: b(l) ARM64 branch out of range (153544076 max is +/-128MB): from +[UnityURLRequest storeRequest:taskID:] (0x00004670) to __Unwind_Resume#0x00000000 (0x09272CCC) in '+[UnityURLRequest storeRequest:taskID:]' from /Users/username/Library/Developer/Xcode/DerivedData/app-ddznnkuubjszymahzwwsyvhwlyin/Build/Intermediates.noindex/Unity-iPhone.build/Debug-iphoneos/UnityFramework.build/Objects-normal/arm64/UnityWebRequest.o
Also, this module is generated by Unity and is uncontrollable.
We can cut our module and avoid the error, but I would like to know how much to cut and how much more room is left for future development.
I tried a normal build and expected the build to succeed without any errors.
Related
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I am pretty sure a set of sequential commands with same input cant
change it's output every time you run it
It might sound stupid . For example while installing an application or bulding using Cmake , atleast for me , i would encounter different bugs each time i run the installer using the same system.
I guess i might have changed the cmake setting or the system settings but it feels so strange and i am totally paranoid about it.
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you never initialize arr but you use it to do M=M-arr[i]; the behavior is undefined
out of that to use an array with a dynamic size is not recommended (ISO C++ forbids variable length array), allocate it in the heap
I've generated an gfortran executable I call mtc08.exe that exhibits the following behavior:
1) If I run it in gdb it runs successfully to the end
2) If I run it normally, re routing the output with the windows command
mtc08.exe >out
It gives me "floating point exception - erroneous arithmetic operation" but does not say where that occurs. (The "backtrace" information is incomprehensible to me, and it seems it cannot contain much information because all is the letter "f".)
Then I'm trying to localize the problem by seeing where the program stops writing results, but having difficulties there also, because I get the impression the program may be multi tasking and proceeding with "future" arithmetic operations before completing output operations that in any case do not interfere.
Does such multi tasking occur? If so, can I turn it off with a compiler switch, so I'm really sure it is doing all operations sequentially?
The currently used compilation command in windows is:
rem debug compilation:
gfortran -static -fdefault-real-8 -fdefault-integer-8 -g -ffpe-trap=invalid,zero,overflow,underflow,denormal -Wall -fcheck=all #mtc08.fls -o mtc08.exe
where mtc08.fls is a file containing the names of all source files.
It may be that by removing some of the "-ffpe-trap" options it would run, but this rattles my confidence, and I'd like to get to the bottom of it, rather than just find a way around.
I can of course give more information, but seeing the error is not localized, that is not so practical.
I still don't know how to get better diagnostics, but still managed to find the cause of the problem by trial and error, which came from an uninitialized variable.
The problem appears to arise because gdb used zero for uninitialized variables, which should have been their values anyhow, and running the same executable without gdb did use values that lead to "floating point exception".
One way to get better diagnostics in gdb is to use -finit-real-nan in the compilation so that uninitialized variables will get more attention from the debugger.
Perhaps with better coding practice, such as intent declarations for all arguments, the debugger would also be better in picking up uninitialized variables without having to initialize them to nan.
I am trying to learn fortran. I wanted to replicate a certain step in a paper but I ran into trouble.
I compiled the file AERsimulation.f95 (I turned on all debugging functions in gfortran I am aware of) I could generate an .out file without any errors (a lot of warnings, however...)
When I tried to run the .out file I got the error message
Fortran runtime error: Index '0' of dimension 1 of array 'k' below lower bound of 1
Now, it is quite difficult for me to understand why exactly this happens. I guess, my question is, whether there is a better way of debugging, so that I can see and click through the code 'live' and see why the error occurs. (I am thinking of the matlab-debugger for instance...)
Any suggestion/hint is very welcome
The files I use are
AERsimulation.f95
AERDATANB.TXT
Thank you very much
Best
Derrick
The meaning of your error message is that you try to access an array element at the position 0 of the array. Arrays in Fortran start at 1 by default.
If you are looking for a better way to debug, try gdb (command line) or if you prefer a graphical interface you can try the Netbeans IDE. It has (limited) support for Fortran an a debugging mode where you can click line by line through the code and see the values of all variables and so on.
On command line try:
gdb name_of_executable
run
the debugger will stop at the line which causes the error.
What are the ".map" files generated by gcc/g++ linker option "-Map" used for ?
And how to read them ?
I recommend generating a map file and keeping a copy for any software you put into production.
It can be useful for deciphering crash reports. Depending on the system, you likely can get a stack dump from the crash. The stack dump will include memory addresses and one of the registers will include the Instruction Pointer. That tells you the memory address code was executing at. On some systems, code addresses can be moved around (when loading dynamic libraries, hence, dynamic), but the lower order bytes should remain the same.
The map file is a MAP from memory location -> code location. It gives you the name of the function at a given memory address. Due to optimizations, it may not be extremely accurate, but it gives you a place to start in terms of looking for bugs that cause the crash.
Now, in 30 years of writing commercial software, this is the only thing I've used the map files for. Twice successfully.
What are the ".map" files generated by gcc/g++ linker option "-Map" used for?
There is no such thing as 'gcc linker' -- GCC and linker are independent and separate projects.
Usually the map is used for understanding decisions that ld made while linking the binary. From man ld:
-M
--print-map
Print a link map to the standard output.
A link map provides information about the link, including the following:
· Where object files are mapped into memory.
· How common symbols are allocated.
· All archive members included in the link, with a mention of the symbol which caused the archive member to be brought in.
· The values assigned to symbols.
...
If you don't understand what that means, you likely don't (yet) have the questions that this output answers, and hence have no need to read it.
The compiler gcc is one program that generates object code files, the linker ld is a second program to combine the object code files into an executable. The two can be combined into a single command line.
If you are generating a program to run on an ARM processor you need to use arm-none-eabi-gcc and arm-none-eabi-ld so that the code will be correct for the ARM architecture. Gcc and ld will generate code for your host computer.
Every once and a while, make errors out with
/usr/lib/../lib64/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status
But there IS A MAIN. This happens on programs that are on build version 50+, and have had a main for months or years.
Best part is if I run make again, doing absolutely NOTHING inbetween, it compiles just fine.
It's a complex build, order of magnitude 50,000 lines of code, cannot realistically reduce to a simple test case. Not worth spending time trying to diagnose, since just re-running make gets past it. But, hoping someone else has encountered this random frustration before.
Perhaps I've made an error somewhere in my CMakeLists.txt files, which allow this to happen periodically but then go away for about 20 more builds. Perhaps there's a rare bug in CMake version 2.6-patch 4, gcc 4.7.0, or ld 2.17.50.0.6-20.el5_8.3, but I'm not finding any other mention of this among the haystack of programmers who actually left out main. At some point I'll be updating cmake and gcc...