So I've been working on a relatively large project by myself, and I've come to realise that some of the variable names earlier on were.. less than ideal.
But how does one change variable names in a project easily? Is there such a tool that can go through a project directory, parse all the files, and then replace the variable names to the desired one? It has to be smart enough to understand the language I imagine.
I was thinking of using regexp (sed/awk on linux?) tools to just replace the variable name, but there were many times where my particular variable is also included as a part of strings.
There's also the issue about changing stuff on a c++ namespace, because there is actually two classes in my project that share the same name, but are in different namespaces.
I remember visual studio being able to do this, but what's the safest and most elegant way to do this on linux?
It's called refactoring, but I don't remember if there's a great way to do it in C++ -- I think maybe Eclipse C++ had it; might be worth taking a look.
Safest (non automated way) way:
Make sure all your unit tests work.
Save everything into source control.
Globally replace var with XXXvarXXX (seriously)
a. Or maybe just the files you think need editing.
Try and compile. Everything that does not compile is easy to undo just remove the XXX.
When it compiles run the unit tests.
When the unit tests work. Do a global replace of XXXvarXXX to the new name.
Make sure the unit tests still work
Save everything in source control.
Tongue only half in cheek. :-)
I remember visual stuio being able to do this, but what's the safest and most elegant way to do this on linux?
You can do pretty much what you used to do in visual studio in Eclipse using the re-factoring tools, which is available for Linux.
$400 a f'n copy, but here you go: http://www.xref.sk/xrefactory/download.html
I've of course never used it.
I know C# and visual studio has a great variable changer, but does it work through all the documents im not sure. I know when you change a variable in C# it pops up in the beside the Variable text. Change All
However you may be stuck with the only option. Change variables and see where the compiler goes wrong. However its not ideal, but may be your only choice
use private variables, rename the variable and the obvious uses, correct the compiler errors.
Related
I am using Emacs + Tuareg mode to do my OCaml project.
It is working fine and I get used to it.
However, along with my project source base getting bigger and bigger, I find managing the project is getting harder and harder.
Especially for refactoring. If I change a module name or function name, I have to search everywhere for the part that need to changed accordingly or I just constantly compile again and again to let compiler tell me where I should go.
It is not convenient.
Anyone can suggest a good way for source base management?
thanks
A good option is TypeRex. This is an alternative Emacs mode created by OCamlPro that has a bunch of OCaml-aware features including proper support for refactoring (like renaming identifiers).
It also has a bunch of other nice features like good auto-complete, semantic grep and so on.
Unfortunately, this involves changing your build process to use some wrapper programs. These generate the additional information the mode needs to function. However, once you get the build set up, it's a really awesome editing environment.
In C++ I can achieve the same results by using a shell script where I write all the compilation instructions. So my question is:
Are there any good reasons in using a makefile?
Do you have any examples to demonstrate this?
One of the main reasons to use a makefile is that it will recompile only the source files which have changed since the last time you built your project. Writing a shell script to do this will take much more work than writing the makefile.
Wear and tear on the keyboard.
Preventing it taking ages to compile everything
Easier to change between compiling for debugging and production
As to examples - See most GNU projects wrote in C/C++
You might want to take a look on autotools. The will make a Makefile for you while they can help with code portebility as well. However, you have to make some relatively simple template files that the auto tools will use to construct configure file and a end user can run ./configure [options]; make. They provide many features to your makefile that a end user might expect. For a good introduction see : http://www.freesoftwaremagazine.com/articles/brief_introduction_to_gnu_autotools
Let's say you do write a shell script. It will work and you will be happy. You will keep using it every chance you get. You will add parameters to it to allow you to specify options. You will also notice that it re-compiles everything, all the time. So you will then try and make it smarter so it only re-compiles the files that have changed. What you will be doing, in effect, is writing your own make system.
That's fine as long as you had a good reason to do it. For example: Existing make solutions don't do X well, so you wrote one to solve that problem.
You, however, don't have a problem that cannot be solved by an existing make system (or at least, it sounds like you don't :) ). The problem you're trying to solve has already been solved. Just read up and use the solution - a make file :)
So, to answer your question, yes, there are a lot - most of which you won't be aware of until you need the functionality. When you do, you will be grateful it already does what you want.
It's the same logic you apply to using libraries in code.
I build my C++ code base with MSVC++ 2008 and 2010. Is it even possible to get translation unit, analyze it, insert some code if necessary and then pass on to the compilation process? Original source code should not be affected.
Sure, it should be transparent for a developer who builds a project. Finally, it will only affect object files. Visual studio is very powerful. I guess, there should be some kind of plugin API or hooks to do that. Please, give me a hint.
I don't believe this is possible as you describe it, though I don't know for sure. It would certainly be non-trivial. The only similar project that springs to mind is OpenMP, but I got the impression that Microsoft was the one who implemented their version of it.
I could see a template engine such as Cheetah sufficing though. You would likely give up your bells and whistles like code completion and intellisense though.
Basically, you would set up the files to use a custom compiler to generate the new code in another file. The C++ compiler would then compile the generated files. I don't think it would be elegant or pleasant to use, to be frank.
I've used CMake to do similar things, though I did not target it as a general tool. I wrote a one off for some content generation.
Maybe if you actually describe some of the specifics of what you want to do we can offer a better solution.
After frequently coming across recommendation not to use leading and double underscores in C/C++ identifiers I decided to fix all our sources once and for all. What I need to do now is convert _Identifier to Identifier_.
Should I use a specialized tool for this task of regular expressions will do for this job? In latter case what is the pattern to match C/C++ identifier?
Although I am one of those that frequently points out that names with leading underscores may be reserved, I strongly recommend you don't do this unless you are experiencing problems caused by the names. Making this global change will make your version control system less useful than it might otherwise be by causing all sorts of spurious diffs. Also, there is a chance of creating duplicate names.
Also, there are many underscore prefixed names that re perfectly valid. One thinks immediately of __LINE__ and __FILE__ etc, and of all the names of non-standard functions that may be provided by
your specific implementation. Filtering out those names will be far from trivial (I would say next to impossible), certainly a simple Perl or sed script will not be enough.
So instead, I would encourage you to change the names on a file by file basis as you make other changes to the code. Change your programming standards to avoid the leading underscore names and write new code in accordance with the standards.
If you use Visual Studio, there are refactoring plugins such as Visual Assist X to help you with this.
Perl should do the job, but there's Coccinelle for when it gets tricky.
Netbeans can do this for the whole project, using the Refactor->Rename menu command. But it only works for a single identifier a time, so you'll need to reiterate for every identifier you need to change.
If your regression tests are solid, then you should have no problems if you just write a quick perl script to replace everything and run the test suite. If you don't have solid regression tests...well, then you can do the perl script replacement and just rebuild the code. If the compilation works, then chances are pretty good that everything is fine. In other words, try the quick solution, and only use a specialized tool if that doesn't work.
Many times when I am watching others code I just want to find where and how a variable is defined. Normally what I do now is look for the type of the variable until I find the definition, that is very time consuming. And I guess that there are some tools that can help me in this rutinary situation. Any suggestion in some tools or commands to help me in this task?.
I know that using a GUI and creating a project this is done automatically I am talking of a way to do this without a GUI. I am working with only text mode. I am running under Linux and I am using C/C++, but suggestions for other languages are welcome.
Thanks a lot.
A possible solution
Michel in one of his comments propose a simple an effective solution define again the variable, in that case in compilation time, the compiler will inform where is the previous definiton. Of course to apply this solution we need to think previously in the locality of the variable.
You've already given the most appropriate tool: an IDE. This is exactly the kind of thing which an IDE excels at. Why would you not want to use an IDE if you're finding development painful without one?
Note that Emacs, Vim etc can work as IDEs - I'm not talking about forcing you the world of GUIs if you want to stay in a text-only situation, e.g. because you're SSHing in.
(I'm really not trying to be rude here. I just think you've discounted the obvious solution without explaining why.)
Edit: OK, you say you're using C++. I'm editing my response. I would use the C preprocessor and then grep for the variable. It will appear in the first place.
cpp -I...(preprocessor options here) file.cpp | grep variable
The C preprocessor will join all the includes that the program uses, and the definition has to be before any usage of that variable in the file. Not a perfect thing, but without an IDE or a complete language description/managing tool, you only have the text.
Another option would be using ctags. It understands the C and C++ syntaxes (among others), and can be searched for variables and functions using command line tools, emacs and vi, among others.
I use cscope and ctags-exuberant religiously. Run it once on my code base and then in Vim, I can use various commands like ^] or [D or [I or similar to find any definitions or declarations for a given word.
This is similar to facilities provided by mega-IDEs like Visual Studio and Eclipse.
Cscope also functions as a stand-alone tool that performs these searches.
I use one of three methods:
I will use CTags to process my source tree (nightly) and then can easily use commands in Vim (or other editors) to jump right to the definition.
I will just use grep (linux) or findstr (windows) to look for all occurrences of the variable name or type. The definition is usually quite obvious.
In Vim, you can just search backward in the scope and often find what you are looking for.
Grep for common patterns for variable declarations. Example: *, &, > or an alphanumeric followed by one or more whitespace characters then the name of the variable. Or variable name followed by zero or more whitespace characters, then a left parenthesis or a semicolon. Unless it was defined under really weird circumstances (like with some kind of macro), it works every time.
In VIM you can use gd to see local variable declarations or gD to see global variable declarations, if they're defined in the current file. Reference Go_to_definition_using_g
You can also use [i to see the definition without jumping to it, or [I to see all occurrences of the variable in all the included files as well, which will naturally show the definition as well.
If you work in Microsoft Visual Studio (which I think you could use for C++ as well, but would require working on a Windows workstation) there's an easily accessible right-click menu option for "Go to Definition...", which will take you to the definition of any currently marked variable, type or method.
if you insist on staying text mode, you can do this with either emacs or vi with the appropriate plug-ins.
But really, move into the 21st century.
EDIT: You commented that you are doing this over SSH because you need the build speed of the remote server cluster.
In that case, mount the drive on your local machine and use an IDE, and just SSH in to kick off a build.