I'm trying to compile 3 cpp files, for only one of them, the g++ compiler on linux is reading spaces between every character on the making it impossible to compile. I get hundreds, if not thousands, of x.cpp:n:n: warning: null character(s) ignored (where x is a name and n is a number). I wrote the program in Visual studio and I copied them to linux. The other 2 files compile fine, I've done this for dozens of projects. How does this happen?
I managed to fix this issue by creating a new file and copying the text from the original cpp instead of copying the file.
Now I get an error from the terminal saying Permission Denied when I try launch the .o file
Your compiler problem is nothing to do with linebreaks.
You're trying to compile a file saved as UTF-16 (Unicode). Visual Studio will do this behind your back if the file contains any non-ASCII characters.
Solution 1 (recommended): stick to ASCII. Then the problem simply won't arise in the first place.
Solution 2: save the file in Visual Studio as UTF-8, as described here. You might need to save the file without a BOM (byte-order mark) as described here.
WRT your other problem, look for a file called a.out (yes, really) and try running that. And don't specify -c on the g++ command line.
There is no text but encoded text.
Dogmatic corollaries:
Authors choose a character encoding for a text file.
Readers must know what it is.
Any kind of shared understanding will do: specification, convention, internal tagging, metadata upon transfer, …. (Even last century's way of converting upon transfer would do in some cases.)
It seems you 1) didn't know what you chose. 2) didn't bring that knowledge with you when you copied the file between systems, and 3) didn't tell GCC.
Unfortunately, there has been a culture of hiding these basic communication needs, instead of doing it mindfully; so, your experience too much too common.
To tell GCC,
g++ -finput-charset=utf-16
Obviously, if you are using some sort of project system that supports keeping track of the required metadata of the relevant text files and passing it tools, that would be preferred.
You could try adopting UTF-8 Everywhere. That won't eliminate the need for communication (until maybe the middle of this century) but it could make it more agreeable.
A piece of source code which was not written by me, my aim is to find a problem with this source code. I've narrowed it down to 20 lines of codes.
In those 20 lines of codes a number of variables and functions are used.
There are upwards of 20 header files and similar .c files that are used to compile this code. I don't want to manually search through all these files.
Is there a way I can find where the function or variable is created and track it from there?
P.S. I'm using notepad++
To build this program I would need my board which I don't have access to, currently (Clarification on the build: I need the board containing the intel-microprocessor to compile and test the code)
You might try running ctags across the files and looking through the human readable cross-reference file to find where various variables and functions are defined.
Notepad++ v6.9.2 has a "Find in Files ..." (Ctrl + Shift + F) function.
Try that.
I'm doing some programming problems from the previous year competition and in the problem text there is only one case, which is simple so I can just rewrite it when testing.
Now, I also have a folder with a bunch of .in and .out files, in format '01.in, 01.out, 02.in, 02.out, etc'.
Is there a way to somehow take one of those .in files and automatically use all the lines of it as input without making changes inside my program but rather doing it directly from the command line?
Thanks
Assuming linux:
cat *.in | yourprogram
On Windows you'd use type instead of cat.
I assume your program takes in and processes the agruments (argv[]) passed to it already. If this is the case, one way could be to write a simple wrapper program (in Python for example) which opens the required .in files, reads the lines in it and invokes your C++ program by passing the required lines as input to them.
Then you can execute this python program or make changes to it as required.
This might be difficult to answer. I am trying to understand some codebase and in one of the project folders named FOO there is a main.cpp file plus other .hpp and .cpp files. These filenames are made descriptive using underscores such as Hi_there_file.cpp etc.
There are two files Foo.tab.hpp and Foo.tab.cpp
Is *.tab.cpp an indication of something or just a poor try at making the file name descriptive?
Turns out, that file is generated by a perl script so they put a tab.cpp at the end. maybe even delete this question. Very very specific to what i'm working with
I'm working on a static library project for a c++ course I'm taking. The teacher insists that we define only one function per source file, grouping files/functions belonging to the same class in subdirectories for each class. This results in a structure like:
MyClass
\MyClass.cc (constructor)
\functionForMyClass.cc
\anotherFunctionForMyClass.cc
OtherClass
\OtherClass.cc (constructor)
Whether this is good practice or not is something I'd not like to discuss, since I'm simply obliged to organize my project in this manner.
I'm working in visual studio 2008, and somehow got strange link errors when using an identically named function (and thus filename) in two classes. This appears to be caused by the fact that visual studio puts all .obj files (one for each source file) in one intermediate directory, overwriting earlier generated object files when compiling identically named source files.
This could be solved by putting the object files in subdirectories based on the relative path of the input file. Visual studio allows one to configure the names of object files it generates and has macros to use in there, but there appears to be no macro for 'relative path of input file'.
So, is there some way to get this to work? If not, is using one project for each class the best work-around?
You are right, by default all object files are put into the same directory and their filenames are based on the source file name. The only solution I can think of is to change conflicting file's output file path in here:
Project Properties-C/C++-Output Files-Object File Name http://img37.imageshack.us/img37/3695/outputfile.png
PS. It sounds like the lecturer has a crappy (probably written by the lecturer himself) automatic code verifier that imposes this restriction. To get extra marks, offer to rewrite the parser so it works with normal/sane/non-weird projet layout.
Real answer:
Change
C/C++ => Output Files => Output File Name
to
$(IntDir)/%(RelativeDir)/
Every .obj file is going to be created in a sub folder so its not going to overwrite the previous on linking.
I can't think of any way to fudge the project settings to get VStudio to automatically split out the intermediate files into separate folders.
You have a few chances -
Build the class name into each file name. Most IDE's display just the file name in the tab view so if you do have several methods in different classes with the same name, its going to be difficult to tell them apart if the file name does not include the class name along with the method name. Which is really why I think your teachers advice is madness. I have not seen any programming style guide advocating that approach. Additionally it goes directly against the way various tools work - if you use Visual Studio to create a class, it creates one cpp file and one header, and automatically appends each new function to the single cpp file.
You could create a static library per class. When linking in static libs the obj files are all packaged up inside the .lib so conflicts are no longer a problem.
Switch comp-sci courses to one thats not being taught by a nut job. Seriously, this guy is completely out of touch with industry best practices and is trying to impose their own weird ideas on their students: Ideas that are going to have to be unlearnt the moment they leave the teaching environment.
You can also change output file name per file in its properties. Just make sure you use different names.
Can you use the class name in the filename to disambiguate? I'm thinking that you might have
MyClass
\MyClass.cc (constructor)
\function1_MyClass.cc
\function2_MyClass.cc
That would mean that every file would have a unique-enough name to defeat the problem. Is that an acceptable strategy?
You could probably arrange the properties of the project to put the object files into a folder which is below the folder of each source file. Once the project has this property, then every source file should inherit this property. (But if you've done experiments like Igor has suggested, then you may need to go through the properties as reset them back to the parent).
Having looked at the help files, I think you should go to project properties/C C++/Outpuf Files/Object File Name: and enter $(InputDir) (no trailing backslash). Every source file should then inherit this property and your .obj files should be separated.
You may need to do a Clean Solution before you make any changes.
Renaming the object files will work, but it's going to be a pain, and it will slow your compile/link cycle down. I've never figured out why, but it seems to confuse Visual Studio if the object files don't have the default names.
You could prefix the funciton name with the class name; e.g. myclass-ctor.cc, myclass-function1.cc etc.
You could have one .cc file per class which #includes the individual function files. In this case you'll need to prevent the #included files from being compiled seperately (either rename their extension or set Properties->Exclude From Build to 'Yes').
Out of curiosity, where does your teacher want you to put free functions e.g. local helper functions that might normally belong in an anonymous namespace?
If not, is using one project for each class the best work-around?
Not a good idea - apart from the fact that you won't end up with a single static library (without even more jiggery pokery), your link times are likely to increase and it will hide a
lot of pertinent info from the optimizer.
On another note; If the course is actually about C++ not OO programming, do what you need to pass but take your teacher's advice with a pinch of salt.
You don't have to put them in different translation units... why not put each function in a .h and include them all in one .cc per class? That will very likely give better output from the compiler.
I'd be asking why the teacher is insisting on this odd structure, too, the reasoning behind it should be explained. I know you didn't ask that of us, so that's all I'll say.
In Visual Studio 2010, I set
Properties -> C/C++ -> Output Files -> Output File Name
to
V:\%(Directory)$(PlatformName)_$(ConfigurationName)_%(Filename).obj
for OBJ files to end up next to the sources assuming the project lies on drive V (no idea whether there is a macro for it, yet).
By the way: $(InputDir) refers to the solution/project directory and will cause the same problem in another directory.