#include内部函数体不起作用（CDT / Eclipse C ++）

Question

This question concerns a C++ project managed with CDT 8.1.2 inside Eclipse 4.2.2 (Juno). The following code snippet will compile but it will be displayed as having errors inside Eclipse.

I have a file named foo.h which reads:

int a = 42;

This file is included in another file foo.cpp:

#include <cstdio>

int main() {
    #include "foo.h"
    printf("%d", a);
    return 0;
}

In my understanding, the #include statement inside the main() function is supposed to trigger a mere copy-paste action in the preprocessor. CDT seems to have indexed the file correctly because I can CTRL-Click on the filename "foo.h" which then opens the file in the IDE. Interestingly, if I move the #include "foo.h" statement just below the #include <cstdio> statement, it works as expected. Is there any option inside CDT to perform preprocessing before resolving symbols?
Side note: I know that this code design is frowned upon, however I need to import code written by somebody else and require content assist set up properly in order to be productive.

Answer 1

Looks like there are many known issues with the code analyser in Eclipse. See for example this question Turn off eclipse errors (that arent really errors) on how to disable some or all of the error messages. Not sure if that "solution" will be good enough for you but from what I understand it should not impact other aspects of the code indexer.

Answer 2

Since any include should just turn out to be some "plain copy&paste" this may well be a bug in Eclipse/CDT.

If you use KDE you may try KDevelop .

I don't know whether there is everything around what you need but I just checked and there is at least no confusion about your minimal example above. (Code highlightning and assist is working as far as I can tell.)

Another quite popular IDE for Linux is Netbeans . I can't give you any information on whether it will support that sort of "inline including" but both of them are popular and worth a try.

^{Perhaps this error is a "hint" for you to refrain from doing what your intention was. I don't know whoever would write code into a header that is mean to be included inline but instead of putting effort in a change of your IDE / search for a new one, you should probably refactor the code, There would be a greater benefit I think.}

Answer 3

Generally, C++ include files (.h, or header files) should be included at the head of the module, not intermingled with the module's code.

It seems you have encountered an error with your development environment that in that it cannot properly handle a header file included in the middle of a function.

Move your #include "foo.h" statment above your void main()... statement and try again.

Answer 4

Your latest update implies that you can use other IDEs. Do they have to support GCC or are you limited to running on Linux or are you simply using CDT to provide call graphing and so on?

Can you use something like Visual Studio express to get the project compiling and use the tools available there to gain an understanding of how the code is structured?

It's unclear if you can actually use another IDE just to understand the code or if you need to be able to deliver it using the alternate IDE.

VS express 2012 works just fine with this style.

Answer 5

Some of my colleagues use Source Insight (commercial, but fair price) and are pretty convinced about it. But unfortunately this is only available for Windows, it seems.

Besides Code Blocks (as others already mentioned) you might try the CodeLite IDE , can't tell anything about their quality compared to Eclipse CDT.

Answer 6

Type extern int a; ...............

Answer 7

How about forward-declaring int a; ?