As a native english speaker, it's hard for me to judge how much of an impediment not being able to work in ones native language is. I guess it must be some, but it's not like English == C++, and sometimes the English names for programming constructs are actually misleading (e.g. "Cookie").
The effect is not noticeable at first. After years of programming, at least for me, it was bugging me increasingly. Even though I am quite fluent in the English language, that still bugged the crap out of me. Maybe I am sensitive. But there are more than just the comfort in it. If you think about how many times you use each syntactic term in C++ when programming. Maybe you print in the term "if" thousands of times each project. The effect adds up. Even so if I would be using my native language, the equivalent "om" in Swedish, that would eventually bug the crap out of me as well. But with a translator, I can switch between two or more variants of that. Now, the most important thing is of course to have the first term in the native language. I also notice that when I use "if", I would prefer writing the comments in English. When I switch to "om", my mind prefer writing the comment in Swedish (my native language). This is because the lowest level of terms, such as "if" would be hard coded in my mind after years of use, and that switches over my mind to its respective language. Each switch to another language takes an additional toll on the mind. (Not huge, but enough to make the mind outside of the comfort zone). So, this is not just an idea. My whole mind actually crave to be able to write in my native language, such as coding. I could get by continue to use the "normal" English terms. But I would be disappointed and less vital in my work.
It's not clear that modifying the IDE itself is the best way to achieve what you want. If I am reading correctly, I think what you have in mind is sort of a pre-processor that converts the users native language source to language that the compiler understands ("program langauge") using a dictionary that maps native "words" to their compile-able equivalent. You also need to be able to convert the compiler messages back to their native language equivalents. At least from the compiler perspective, the best way to do this might be a command line tool that wraps around the GCC toolchain that handles the necessary conversions. You could then add support for this in Code::Blocks (or any other IDE that has flexible build system) by calling your commandline tool instead of the regular GCC toolchain.
A such wrapper may indeed be the best way to do it. If it is decided that such is the way to go, then I will do it. The problem may be that I need to write one such tool wrapper for each compiler. That can get nasty considering how variants of MinGW, MinGW64, and now TDM keeps emerging.
On the other hand, allowing the user to use their native language for code completion (and other things like class and project wizards) would require very significant changes to the IDE. The CC parser would need to convert the native language to program language when parsing, and tokens would need to be converted from program language to native language for display in the UI.
I was kind of hoping that there would be a solution that would not require huge changes to the IDE. Actually, I am already running a command line tool for all my programming tasks that already translates the code. And this works. Also it works for debugging.
The reason that I still am bugging you over this are first, I like to make this available to everyone as an option in the world of programming. Also, an additional bonus would be if the code completion would work with this, but for me personally, that is not necessary. I get by without the full code completion.
At least, I do not want to place any burden on you folks, so I hope a simple solution is possible without too much effort. That is why this needs to be discussed, so we can figure out if there is a solution that simple enough to implement in CodeBlocks. I think it could be a good reputation for CodeBlocks if it could brag about this feature. I am not sure, just intuitively I think it would be a winning concept.