I'm using a library with an include structure where the .h files are all in a single directory. These .h files contains a single line, a #include directive which points to the 'real' header file in specific source folder locations. The #include path in these files is relative.
So, here's an example. The directory structure is:
/project
/sources
<my .cpp files>
<my .cpp files>
...
/include
/component
foo1.h
foo2.h
/platformA/something/foo1.h
/platformB/somethingelse/foo2.h
/include/component/foo1.h contains a single line of code:
#include "../platformA/something/foo1.h"
/include/component/foo2.h contains the single line of code #include "../platformB/somethingelse/foo2.h"
In my sources, I simply have:
#include "component/foo1.h"
The header search path for my project points to /include
Now, Xcode 4 is able to find component/foo1.h in /include, but it's unable to follow the relative include path within those headers and find the 'real' foo1.h in the `/platformA/something' directory, and so on.
I suspect it's because the include paths in the top-level foo1.h file is relative to its location, but Xcode might be treating it as relative to some other location (project root or something)? FWIW, Visual Studio has no problems with an identical configuration.
What can I do to remedy this?
From your directory structure it seems that the directories platformA and platformB are placed outside the include folder. There are two possible solutions to this:
Solution A
Move these
to include folder.
Solution B
Add project/platformA and
project/platformB to the
directories where include files
should be looked for in project
settings.
Don't use relative paths. Seriously, it's implementation-defined behavior how they work, so different compilers/environments/platforms will behave differently, and in your case, Xcode is almost certainly invoking GCC or clang in some sort of "build" directory, which may or may not be a sibling to your sources directory.
It's not worth the headache.
Put platformA and platformB in include, or add another directory (say, platform-include) put them in there, and add that directory to your include path.
Related
Sorry if my phrasing of the question is a bit confusing:
How do I set includes to be relative to the relativity of the source file from the root path?
I am trying to compile a C++ project (not my own), and there are two folders: src and include.
The .cpp source files are located in src and the header files are located in include.
I would like to compile all the source files.
However, the #includes in the source files are relative, as if the include folder tree and the src folder tree were merged.
For example src/foo/bar/baz.cpp might have #include "baz.h". In this scenario, the header file is supposed to be searched for in include/foo/bar/baz.h rather than include/baz.h.
How do I achieve this with GCC? I'm sure a similar question exists on the internet already, I just can't figure out how to phrase my question well.
Here is what I've tried so far which is incorrect:
gcc src/**/*.cpp -I include
Note: I still need to be able to append additional -I <folder> at the end of the command for including files the normal way.
There is no magic compiler option to do what you want.
Solution 1: Change the #include directives to be relative to the include directory.
Solution 2: Don't use separate directories and move the headers into src directory.
I started coding in C++ few days ago. I am using windows as my OS for writing code. I have been keeping all of my "well-written" codes in a single location. Now, I am working on a project that requires the use of those codes. So, I planned to include those files that I require as header files in my project. However, to make my project "self-contained", I created shortcuts of those folders that I require and kept them in the source folder of my new project and decided to use relative paths to the shortcuts in the "include" statements in my project.
However, I am getting an error. Is there any way to use relative (or, in general, absolute) paths to shortcuts in the include statements of C++ in windows?
Thanks.
It really depends on how you include the header files.
If you include with double-quotes, like e.g.
#include "some_header_file.h"
Then the relative path is from the current files location.
If you include using angle-brackets, like e.g.
#include <some_header_file.h>
Then the relative path is based on the system include paths.
You can always add a path to the system include path. How to do it depend on your environment and compiler. If you're using Visual Studio you go into the project properties dialog, and in the "C/C++" / "General" tab there is a field called "Additional Include Directories" where you can add directories. (This is for VS 2015, might be a little different on other versions.)
Regarding double quotes inclusion. Lets say your project hierarchy looks like this (on disk!):
Project
|-- Include
|-- Source
| `-- MoreSource
`-- Other
In Project/Source you have your source files, and if one of them want to include a header file from Project/Include, then it will look something like
#include "../Include/header.h"
Now if you have a source file in Project/Source/MoreSource that want to include the same header file it will be
#include "../../Include/header.h"
It could be useful to add the Project/Include directory to the system header search path. You can still use double-quotes to include the files, since if they are not found then the preprocessor will search the system paths as well, but you don't need the "full" relative path. If you add Project/Include to the system header path, you could write just
#include "header.h"
Or
#include <header.h>
Be careful though, if you have a header file with the same name as an actual system header file you might have some trouble.
From https://superuser.com/questions/253935/what-is-the-difference-between-symbolic-link-and-shortcut
You can't include folder shortcut since it's a file, not a folder.
You can read the guide to create symbolic link on windows.
Eigen is located in the file
C:\Users\jherb_000\Downloads\eigen-eigen-07105f7124f9
I thought to include eigen you just use
`#include "C:\Users\jherb_000\Downloads\eigen-eigen-07105f7124f9\Eigen/Dense" `
But it is not compiling. I know it can work because I have done it before, and the eigen website does not explain how to do this unless you are using specific programs like g++.
Since you imply via the tags that you're using qt-creator, your problem boils down to "How do I add an include directory in qt-creator?" There are answers for that here, here and others. One thing to note is that the path you should add is C:\Users\jherb_000\Downloads\eigen-eigen-07105f7124f9.
What happens is when you include a specific file in a specific directory, if that file doesn't #include any other files (ok, other files that aren't in the include paths) all works well. But if it does, (and Eigen files include other file in the Eigen project) then the compiler does not know where to search for them. That's why you have to explicitly tell the compiler which directories to look for files that are included.
Very easy. Let's say you have a dependencies directory, and inside you have the eigen directory. In your .pro file, you could add your dependencies path to your INCLUDEPATH:
INCLUDEPATH += ../dependencies/ # or wherever that path is (relative to your .pro file)
Then, to include the Dense module, you do:
#include <eigen/Dense>
where eigen refers to your folder eigen in your dependencies folder. Many variations possible in function of your setup, but you got the idea.
Ok then what you need to do is:
Copy the C:\Users\jherb_000\Downloads\eigen-eigen-07105f7124f9\Eigen directory and all it's contents to wherever you're keeping all your third-party library files on your machine. (You probably wouldn't want to keep these files in your Downloads folder). For example let's say this directory is copied to C:\jacks_code\Eigen. Then,
Add this new directory to Qt-creator's list of directories to search (see Aki's answer for links):
In each of your source files, to include the Eigen templates, use the preprocessor directive:
#include <Dense>
The compiler will use the directories you told it, to dereference the file to C:\jacks_code\Eigen\Dense (the complete filename). It's a bit confusing here because the files in the root Eigen folder don't have .h or .c or .cpp or .hpp extensions.
Hope that helps. You can also read the INSTALL file in the base of the unzipped package.
In netbeans I am creating a new folder and adding header files to it.
Now when I include the header file within the newly created folder to another file by using:
#include "folder1/myheaderFile.h"
The compiler complains that it is unable to find the header file.
The error is:
main.cpp:31:39: fatal error: folder1/myheaderFile.h: No such file or directory
Is there some way out as I want to include the header files within a folder in my #include?
EDIT: Do i need to make a makefile for every folder?
Another EDIT:
When I right clicked on the error its showing
unresolved directive
#include
Analyzed system include paths:
/usr/include/C++/4.6
/usr/include/C++/4.6/x84_64_linux_gnu
/usr/include/C++/4.6/backward
/usr/lib/gnu/x86_64-linux-gnu/4.6/include
/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu
/usr/include
Here's for your convenience:
The include file paths you have specified are for system-wide headers. Is the header you are including yours or downloaded/installed system-wide? Do you see the path of the header in the output?
If you are including the header which is in a folder, from another folder, then you need to traverse back, i.e: #include "../folder/header.h"
If this is a system folder, such as the ones residing in /usr/local/include in my system, all you have to do is
#include <header.h>
or if it resides in a sub-folder (quite often),
#include <Libname/header.h>
As long as you have set the include paths pointing at it, it should work.
To setup the include paths and directories, see example: http://zetcode.com/articles/netbeanscdevelopment/ near the end of the page.
Remember that when you hardcode paths, you need to take into consideration the current path of the file which is including the header.
Alternatively, you can use cmake & make (don't know what Netbeans uses), where you define everything your self.
You can test with full path, i.e:
#include "/home/user/project/folder/header.h
or you can test from command line and set the include path.
Hope it helps :)
I am working on a project and I keep getting stumped on how I am supposed to import files from a different directory. Here is how some of my files are organized:
-stdafx.h
-core/
-->renderer.cpp
-shapes/
-->sphere.h
-->sphere.cpp
how can i access the stdafx.h and shapes/sphere.h from the core/renderer.cpp?
There are many ways. You can #include "../stdafx.h", for instance. More common is to add the root of your project to the include path and use #include "shapes/sphere.h". Or have a separate directory with headers in include path.
One (bad) way to do this is to include a relative path to the header file you want to include as part of the #include line. For example:
#include "headers/myHeader.h"
#include "../moreHeaders/myOtherHeader.h"
The downside of this approach is that it requires you to reflect your directory structure in your code. If you ever update your directory structure, your code won’t work any more.
A better method is to tell your compiler or IDE that you have a bunch of header files in some other location, so that it will look there when it can’t find them in the current directory. This can generally be done by setting an “include path” or “search directory” in your IDE project settings.
For Visual Studio, you can right click on your project in the Solution Explorer, and choose “Properties”, then the “VC++ Directories” tab. From here, you will see a line called “Include Directories”. Add your include directories there.
For Code::Blocks, go to the Project menu and select “Build Options”, then the “Search directories” tab. Add your include directories there.
For g++, you can use the -I option to specify an alternate include directory.
g++ -o main -I /source/includes main.cpp
The nice thing about this approach is that if you ever change your directory structure, you only have to change a single compiler or IDE setting instead of every code file.
You can either use relative paths:
#include "../stdafx.h"
#include "../shapes/sphere.h"
or add your project directory to your compiler include path and reference them like normal:
#include "stdafx.h"
#include "shapes/sphere.h"
You can use the /I command line option to add the path or set the path in your project settings.
You can use g++ -I /source_path /path_of_cpp to compile. /source_path is the path of the header file. Additionally, you can include the directory in which the header file is located in CPATH.
You can locate the header file by entering the following in the terminal locate header.h. The folder thus obtained can be extorted to CPATH using export CPATH = /source_directory. Replace /source_directory with the path of the directory obtained from locate header.h