Error can not open source file "..." - c++

I'm using VS2010 (downloaded via dreamspark) and although I can open the #include file by right clicking on it and pressing on Open Document, it complains "Error can not open source file "..."" which seems rather absurd. I'm using Qwt with Qt this time around and I'm specifically having the problem for:
#include <qwt_counter.h>
#include <qwt_plot.h>
(And I am using the "<>"); not sure how to make those appear properly in the code above.
Thanks in advance.

As Neil indicated, try using quotes instead of the <> characters around the filename. When using the quotes, MSVC will look in the same directory as the file the #include is in for the specified file, then if it's not found there will look in the directories specified by the include path. When the filename is surrounded by <> characters, the current file's directory isn't looked at - the compiler goes right to the include path.
See http://msdn.microsoft.com/en-us/library/36k2cdd4.aspx for details.
Note that this is an implementation dependent behavior - it might not apply to other compilers.
If that doesn't help, make sure that your include path contains the directory that the file is located in by setting the "Include Directories" property appropriately:
http://msdn.microsoft.com/en-us/library/t9az1d21.aspx
Finally, you might be using a makefile project (I'm not sure how common it is for Qt projects to continue to use qmake when built from VS) , in which case you'll need to perform whatever configuration is necessary in the make file(s) or parameters passed on the command line that invokes the makefiles.

Is the path where these files are located either the same as that of this source file, or included in the "additional include directories" in your project settings?
Project -> properties -> c/c++ section -> additional include directories.
If they are located in a subdirectory of the source file you're editing or of one of the additional include directories (I think) you can also include them with:
#include <path_to_file_1/qwt_counter.h>
#include <path_to_file_2/qwt_plot.h>
[edit]
or of course what neil says
[/edit]

It turned out there was a circular linking happening and I had all my code in a .h file. I split it up and added the corresponding .cpp file, now everything works fine.

Related

Moved files in project and now I can't find namespaces

I previously had all of my source files in the same folder just scattered about, but I was getting tired of the disorder, so I created a folder hierarchy and organized my headers and .cpp files in those folders, and changed the ClInclude tags in the projects .vcxproj file accordingly. I then changed all the #include rows in the source headers to match the new location of the headers.
Now when I compile I get a heap of errors saying that the namespace "math" can't be found. The namespace could be found before the file organizing, so the problem should be something with that, but that #includes works fine.
If I write
using namespace
the autocomplete finds the namespace just fine, and no red wiggly lines show up in the text interface.
I'm using VS17 Community.
There are actually two ways to resolve your issue. You've already noted the first, that you can always use relative paths (relative to the source file).
#include "..\Math\math.h"
This will work just fine. You can also modify your C++ Project Properties to add a list of include directories. This will be very useful for you when you begin working on projects that use a lot of libraries To add include directories you need to:
right-click on your project in the solution explorer and select Properties.
In the left pane, click on the C/C++ > General tab.
On the property that says Additional Include Directories, click the drop down arrow (you may need to click inside the text first) and select Edit...
From here, you can add a list of include directories that you will be using with your project. You can use:
Absolute Paths
C:\Path\to\Math
Relative Paths (relative to your .vcxproj file)
..\..\relative\path\to\Math
Macros (Visual Studio will list your available macros)
($SolutionDir)..\path\to\Math
You'll see the use of the macros a lot when it comes to C++ and other Visual Studio projects not just for include directories, but for build events as well.
Once you've added a list of include directories, you can go back to including your headers in the source code as normal:
#include "math.h"
In the event you need to use a relative path from one of your included folders, you can do that as well.
// some directory inside of Math
#include "MoreMath\moremath.h"
// some directory above Math
#include "..\AboveMath\abovemath.h"
Hope this helps!
I solved it...
Remove this question if necessary. The problem was that I didn't backtrack the filepath in my #include "math.h". They should instead have said #include "..\Math\math.h".

Additional include directory in Visual studio 2015 doesn't work

I was trying to re-use an available source code for my own project, it can be found here:
https://github.com/TadasBaltrusaitis/OpenFace
I tried compiling project FeatureExtraction of the original code, everything was fine. Then I created a new empty project and added the following #include:
#include "LandmarkCoreIncludes.h"
#include <Face_utils.h>
#include <FaceAnalyser.h>
#include <GazeEstimation.h>
These are exactly the same as in project FeatureExtraction in the provided source code. I've already changed the additional include directories in C/C++ general tab into:
$(SolutionDir)\lib\local\FaceAnalyser\include
$(SolutionDir)\lib\local\LandmarkDetector\include
However, it still gave me "cannot open source file error".
Update: If I put the absolute path of the header file directly to the code it is OK, however if I put the absolute path to the Additional Include Directories, the error remained.
Use #include "header.h" instead of the one with diamonds (< and >) which looks in another directory.
After that, check if the header files really are in these directories. If they are, you should check the $(SolutionDir) ( I don't use a '\' after the $(SolutionDir) but it may work out as well).
Try to locate and delete the .suo file and restart VS
Looks like I had same "bug" as mentioned in this post here:
Visual Studio does not honor include directories
After having changed the Additional Include Directories for all platforms instead, the code was compiled without any errors.

How do I include a header file located in a specific folder? (C++)

I want to include a specific header file (MyHeader.h) in a C++ project. The solution for my project is located in the folder:
C:\\Projects\\MyProgram
The header file is located in the folder:
C:\\Projects\\MyProgram\\Files
I tried the following line of code, but it doesn't work.
#include <Files\MyHeader.h>
Is there an easy way to include the header file without adding the full path to "Include directories" in the configuration properties?
Thanks in advance for any help. :)
Try this
#include "files/myheader.h"
It will work if the header is in a files folder in the same directory as the current source.
If you're trying to include a 3rd party library and not your own header, I'd suggest you to save the library headers in a particular path (say C:\Library\headers). (If there are static libraries put them in some other path like C:\Library\lib).
In your Visual Studio C++ Project, go to View > Other Windows > Property Manager.
Double Click on the Project Name. You will see a dialog box like this:
Make sure All Configurations is chosen in the dropdown, if you want the change to be applied to both the Debug and the Release Configurations. Else just choose the Configuration you want the properties to be applied to.
Go to VC++ Directories on the left and choose Include Directories in the right, and enter the path(s) in the textbox separated by a ;.
You can also use the drop down and use the Dialog box to add the paths if you'd prefer to browse to each path separately
Add the library path the same way to Library Directories
Save the changes using the Save button on the Property Manager Pane's toolbox.
You will then be able to access the header file contained in the directory you added by something like:
#include <myheader.h>
This approach will help, because it won't matter where the headers saved. The header path is not hard-coded.
The current directory of the source file is always searched, although if you use angled brackets it is searched after your include path, whilst if you use quotes it will be the first directory searched.
The directory of your solution or makefile/project file is irrelevant, the local path is relative to the compilation unit, i.e. the cpp file.
If that cpp file includes a header, that headers own includes are relative to itself, not the cpp file that included it. (It would be hell to manage if it were not).
Ideally you should use forward slashes in paths too.
Your actual correct setup here is to include the solution directory in your search path. If it is Visual Studio you can use a macro for this, $(SolutionDir) I think.
That means that if anyone else is going to build your solution, they can put it in a directory they choose and as long as the structure underneath is the same, it will still work.
To use a relative path in your cpp file without any include directory settings, you might need something like:
#include "../Files/MyHeader.h"
You just need to replace your brackets <> with double quotes "" like this:
#include "Files\MyHeader.h"
Brackets is used when you want Visual Studio to find the path from your project settings and double quotes when you want to access the header from a specific path or relative to your project.

Xcode cannot find #Include<> header

I'm trying to get Xcode to import the header file for Irrlicht.
#include <irrlicht.h>
It says "Irrlicht.h. No such file or directory". Yes Irrlicht.h with a capital I, even though the #include is lowercase.
Anyway I added "/lib/irrlicht-1.6/include" in the header search paths for the Xcode project, yet it still doesn't find it.
The only thing I've tried that does work is:
#include "/lib/irrlicht-1.6/include/irrlicht.h"
This is a bit ridiculous though, #include should work, I don't understand why it isn't working.
Update (here are more details on the error):
/lib/PAL/pal_benchmark/palBenchmark/main.h:31:0
/lib/PAL/pal_benchmark/palBenchmark/main.h:31:22: error: irrlicht.h: No such file or directory
I figured this out. Perhaps someone can comment as to why this is the case.
The Header was located in this directory:
/lib/irrlicht-1.6/include/
If I added that path to: "Header Search Paths" Xcode still wouldn't find the path when I built the project.
Solution: Add the header path to: "User Header Search Paths" instead.
It boggles me why I had to do this, as I frequently add my header paths to "Header Search Paths" and then #includes just work. Hopefully this can help someone else who gets this same issue.
Both
#include <irrlicht.h>
#include "irrlicht.h"
should work as long as the "-I" argument to gcc includes the path of the directory enclosing the header file. If irrlicht.h is part of /usr/include the "-I" option is no longer required.
Rather than explicitly adding include paths to your project settings, an easier and more convenient solution for this kind of situation is to just drag the directory containing your .h files (/lib/irrlicht-1.6/include in this case) into the project files pane. This adds the headers to your project of course, and makes it easy to browse them and search for symbols, etc, and it also adds the directory path to gcc compiles, so that you don't have to manage include paths explicitly.
and furthermore, a flat file hierarchy isn't what you want. Dragging files into Xcode flattens your hierarchy. What about for example when you want to have multiple Targets, with a "TargetName/settings.h" file for that target. you'll have many settings.h files that you need to keep unique via its folder name.
I understand that this is an old post, but it does rank quite high on Google, so I thought I would add some information
Under XCode 3.2.6, I had an issue where XCode could not find a header file. It turns out that one of the filepaths included a space in it, and XCode interpreted it improperly.
For example: With a path like "Users/Username/Desktop/Project/Some Headers"
Here was the excerpt from the GCC Commandline: "-I/Users/Username/Desktop/Project/Some" "-I/Headers"
To see your build log provided by XCode, there is a good tutorial here: How do you show Xcode's build log? (Trying to verify if iPhone distribution build zip was created correctly.)

using header files from another project (directory)

I am using Visual Studio 2008, and I need to use certain header files from another project. I have tried to add the path in "Additional Include Directories" in C/C++ General properties pane, but my project still puts out the same errors
(fatal error C1083: Cannot open include file: 'tools/rcobject.h'.
All the other cpp and header files I am using I added as existing files from another directory, and for some headers it puts out an error and for others it doesn't. There was no change in errors after adding additional include directories.
Can someone help me, I am stuck as I need to Debug...
In the "Additional Include "Directories", did you put the path to the "tools" directory, or the path to the directory that includes the "tools" directory? It needs to be the latter.
How the preprocessor works to resolve #include directives, is to take the path specified in the #include and then append it to each of the paths specified in the "Additional Include Directories" (and some other places specific for the project). So, you need to make sure that the path specified in the "Additional Include Directories" plus the path you gave to the #include exactly matches the path to the file you are trying to include.
For example, suppose you have the following file you want to include:
c:\blah\bletch\foo\bar.txt
Then you did this:
#include "bar.txt"
Then you would need to make sure that "c:\blah\bletch\foo" was in the "Additional Include Directories".
Or if you had done this:
#include "foo\bar.txt"
Then you would need to make sure that "c:\blah\bletch" was in the "Additional Include Directories".
Enable the build log (I don't know from the top of my head where it is, shouldn't be too hard to find) and see if the paths you specify appear in the compiler command line. If not you're probably doing something wrong. Using additional include directories should just work. Just make sure you're using the right directory separator and you fill them in under the correct configuration (Release/Debug).
Regards,
Sebastiaan