I need the code I am writing for a project to match some style guidelines. However the standard templates included with CDT don't match this style. Especially the layout of the header guards is not the way it should be. I had a look at the template and for my Eclipse it looks like this:
${filecomment}
#ifndef ${include_guard_symbol}
#define ${include_guard_symbol}
${typecomment}
${declarations}
#endif /* ${include_guard_symbol} */
So I am guessing the variable ${include_guard_symbol} is set somewhere in the CDT, but is it possible to change this setting without needing to modify the CDT itself?
On a slightly different, but related note:
Is it possible to add your own templates, so you just could add new files of other types (test-cases, specialized classes etc) using the normal new dialog for the project?
We've had a similar struggle on our project. One solution is to throw out ${include_guard_symbol} in the template all together, and define it yourself, possibly using some of the other predefined variables. Something like this:
${filecomment}
#ifndef MyProject_${file_base}_h
#define MyProject_${file_base}_h
${typecomment}
${declarations}
#endif /* MyProject_${file_base}_h */
So for a header file named inc/Foo.h, the include guard would be inserted like this:
#ifndef MyProject_Foo_h
#define MyProject_Foo_h
Unfortunately, there doesn't seem to be a way to customize much beyond that. For example, if I defined a class nested in a namespace, I might want to put the namespace as part of the include guard. I can't find a way to do that in eclipse, currently.
So in the Preferences dialog under C/C++ -> Code Style -> Code Templates you can modify the template to be closer to what you need, for example if you need the namespace in the guard, you can do something like.
${filecomment}
#ifndef ${namespace_name}_${include_guard_symbol}
#define ${namespace_name}_${include_guard_symbol}
${includes}
${namespace_begin}
${declarations}
${namespace_end}
#endif /* ${namespace_name}_${include_guard_symbol} */
Related
Imagine you don't want to enable GCC_TREAT_WARNINGS_AS_ERRORS. Because you are working on an epic legacy code and you don't want to make all 999+ warnings to be errors! But we want it for some cases:
#if DEBUG
#warning("Change this on production")
#else
#error("Change this on production")
#endif
Is there a way to create a custom one? For example something like:
#criticalWarning("Show correct message for errors")
I have added some debugging code to my app which I want to call only when needed. I remember there is some kind of IFDEF that can be used to conditionally include code into a source file.
For example I might have something like this:
IFDEF kDebugEnabled == YES {
// some debugging code here
}
And then this piece of code is only compiled into the binary if that kDebugEnabled is YES.
How can I do something like this?
Please note: I don't want to use the project compiler flag settings. I just want to define a BOOL (or something that serves the purpose just as well) which is true or false and then just easily set it in my App Delegate for example. I find it hard to navigate to the project compiler settings, searching for a flag and then setting it. I know there is a Debug flag which might be of use.
What you are looking for is:
#ifdef __YOURSYMBOL__
<conditional code>
#endif
You can programmatically define __YOURSYMBOL__ like this:
#define __YOURSYMBOL__
__YOURSYMBOL__ can be any string that makes sense to you to remember why you are including/excluding that code snippet.
The DEBUG constant is a special preprocessor constant that the compiler defines specifically for you when the code is built for debugging, so you can simply use it:
#ifdef DEBUG
<conditional code>
#endif
Take into account that this is the C-preprocessor, not C, nor Objective-C that you are using, so a test like kDebugEnabled == YES (where kDebugEnabled is an Objective-C variable) is simply not possible. You can define integer values for your constants, like this:
#define __LOG_LEVEL__ 3
and then test for it:
#if __LOG_LEVEL__ == 3
...
Endif
As far as I know, you can't have code in your classes that is not compiled into the final product without using compiler flags. However, using the DEBUG flag is a lot easier than you think. If you are using Xcode 4, it's set up for you by default.
#ifdef DEBUG
// Your debug-only code goes here
#endif // DEBUG
Xcode has, by default, two configurations, Debug and Release. When you use the debug build configuration, among other things, it sets the DEBUG compiler flag, which you can then use to conditionally compile code. No need to mess with compilation settings at all.
Is it possible to tell Doxygen to expand macros but ignore other preprocessor directives?
Take the following into account:
#if defined(linux)
#define OS_LINUX
int function() { /* ... */ }
// Other functions defined for Linux
#elif defined(__WIN32__)
#define OS_WINDOWS
int function() { /* ... */ }
// Other functions defined for Windows
#else
#error "OS unsupported."
#endif
In this case, I want the functions for both Windows and Linux to show up, but I also want the macros OS_LINUX and OS_WINDOWS to show up in the documentation as well. Is there a way to document both macros while ignoring the #ifs?
No, you cannot do that you will have to build the documentation for each configuration separately. However if both Windows and Linux have the same interfaces defined, the documentation will surely be the same for both functions in any case?
By default if Doxygen finds documentation for a declaration in a header and documentation for corresponding definitions in source-files, the documentation in the header will be used. In this case you can use this to your advantage by only placing Doxygen mark-up in the header files. Normally the interfaces will be identical cross-platform and you will have a single header, but multiple implementations for each platform, either in separate sources or using conditional compilation.
I have an XCode project with 2 targets (both are iPhone apps sharing 95% of the same code).
However, one module isn't "shareable"; the implementations are too different.
My solution (that is not working) was to add 2 subdirectories to my Classes/ folder in my project directory - one for each target. In each directory, I've placed a view controller class, called ExampleSentencesViewController. Of course, each file is compiled as part of only one of the targets - I'm looking for an "automatic switching" of which implementation to use based on the target.
Inside each target's settings, I added each directory to the "Header Search Paths" setting (each path for each target).
Oddly, it only compiles for the original target. The target I added later won't compile, claiming that I've included the same header twice (there ARE two files, to be fair). How do I get XCode to forget about the original header??
I've tried deleting the .h files out of my project, but that does not seem to help.
Any help is appreciated.
fully qualify the header paths in the separate implementation files, based on one of your defined search directories:
#include <MONProject/Source/ExampleSentencesViewController.h>
vs
#include <MONSecondProject/Source/ExampleSentencesViewController.h>
update based on clarification:
ideally, you'd create a static library for the shared code.
for a simple case... you could take the direct approach by populating a header in your project's root, named ExampleSentencesViewController.h, and populating it like so:
/* you must define either MON_BUILD_MON_FIRST_PROJECT or MON_BUILD_MON_SECOND_PROJECT at the target level */
#if (defined(MON_BUILD_MON_FIRST_PROJECT) && defined(MON_BUILD_MON_SECOND_PROJECT))
#error invalid configuration: you cannot specify both projects to be compiled
#elif defined(MON_BUILD_MON_FIRST_PROJECT)
/* some fully qualified path: */
#include <MONFirstProject/ExampleSentencesViewController.h>
#elif defined(MON_BUILD_MON_SECOND_PROJECT)
/* some other fully qualified path: */
#include <MONSecondProject/ExampleSentencesViewController.h>
#else
#error uh... which project are you trying to build?
#endif
or you could just use these defines to conditionally enable/disable the interface and implementation of the classes with duplicate names (and then just include them both in the project's declaration of:
/* MONFirstProject/ExampleSentencesViewController.h> */
#if defined(MON_BUILD_MON_FIRST_PROJECT)
#interface ExampleSentencesViewController : NSViewController
/* ... */
#end
#endif
…but this will require to include both headers in your distribution (if applicable).
some of the finer details of inclusion can vary based on how you've declared your search paths (e.g., are they recursive or not?) and whether you use copy headers build phases in your xcodeproj. maintaining both projects which share code can become messy if you've been too relaxed in your include directives, discovery options, preprocessor declarations (conditional compilation/visibility) and/or build configurations so... that's why i recommend a library for the shared bits. this conditional stuff (in the two previous examples) is error prone and doesn't evolve or scale well. doing this is also a good way to confuse other tools in the development toolkit.
in fact, i prefer this over the preprocessor (assuming you're able to distribute both classes):
- (UIViewController *)newViewControllerForMyAwesomeView {
if (IsAppMONFirstProject) {
return [[MONFirstProjectViewController alloc] init...];
}
else if (IsAppMONSecondProject) {
return [[MONSecondProjectViewController alloc] init...];
}
else {
assert(0 && "definitely break up your code, now that it is referenced by 3 or more projects");
return 0;
}
}
if you're merely maintaining two versions of the same title, then practices will be much different.
anyways... this should be enough ideas to solve your problem - you just have to determine the lesser evil.
Is it possible (and how) to add the namespace in the name of the automatic generated include guards in Eclipse CDT, when creating a new class using the .hpp/.cpp templates?
For me Eclipse generates a new class with a namespace nicely, but the include guards do not contain the namespace, so if the same header file exists twice in two different directories, only one can be included.
In my case the name of the namespace, the Eclipse project name and the name of the source directory are all the same, so these could be alternatives as prefix for the include guard.
So in the Preferences dialog under C/C++ -> Code Style -> Code Templates you can modify the template to be closer to what you need, for example if you need the namespace in the guard, you can do something like.
${filecomment}
#ifndef ${namespace_name}_${include_guard_symbol}
#define ${namespace_name}_${include_guard_symbol}
${includes}
${namespace_begin}
${declarations}
${namespace_end}
#endif /* ${namespace_name}_${include_guard_symbol} */`
There's a hidden preference you can set to get at least the file's path or a uuid in there instead of just CLASSNAME_H_. See my full answer here.