This was an issue we've been dealing with for a while now - we're building a C++ project using the Cygwin toolchain, and no matter what we add in the C++ compiler include paths under project settings, Eclipse can't seem to find the necessary header files.
We have done everything the Stackoverflow community has suggested so far;
Made sure include paths were workspace-relative
Tried backslashes and forward slashes
Tried using Cygwin-specific paths (/cygdrive/c instead of C:/)
Checked the compiler output to verify include paths are there
Checked the generated makefiles to make sure they're correct
Rebuilt the index
Deleted the debug folder entirely
restarted Eclipse
Basically nothing short of changing the #include <...> code itself to use a full path (C:/.../file.h) worked. This doesn't work for our needs as we need multiple developers to be able to work on this project, and the files themselves are generated dynamically as a result of some of our build procedures.
So here's a fun little detail about Eclipse we didn't know - specific source files themselves can have their own settings.
If you look at your source files and see the following wrench icon, this means that file has some settings which may be contrary to your project-specific settings.
As a result, our source-specific settings were overriding the include paths, so for those files, none of the headers could be found. The best part is that Eclipse doesn't tell you in any way more explicit than this - the wrench icon does not offer a tool-tip to explain what's going on.
Simply right click on the file > go to Resource Configurations > Reset to Default...
Your header files will be found now, provided that you've written the correct include paths in your project settings.
For reference, we're using Eclipse Kepler - I'm not sure if they fixed this and added more info for users in newer versions.
I created a project by opening an already existing folder. There are some include files I need to add, otherwise Eclipse won't find references. If I right-click on the folder, I don't see the usual option I would see with a regular project. Is there a way to tell Eclipse where to look for w.r.t. include files?
What do you see then if you do not see the usual option? There is also a way to set paths in eclipse preferences, not just the project preferences. Did you try it?
i want to edit cpp files in Eclipse but can't open the folder that contains the cpp files.
The folder symbol is a folder with an exclamation mark at the bottom right. I tried to look up the meaning of the symbol in the eclipse docs but didnt find something. Maybe a bit more background: the cpp files belong to a cocos2d-x application, eclipse cdt is installed. The files are normally accessible with notepad++ or any other texteditor but eclipse just doesn't list them. Refresh, clean or restart didnt help either. Maybe you guys can help me out.
The esclamation Mark deals with build path problem. This problem are usually related with eclipse metadata, probably rebuilding the Index Will fix it, but the easiest thing is delete the project (without deleting from disk) and import the project using import existing project into workspace. Male a backup before any operation.
Found the problem, a little fault in the path, edited the folder properties now everything works!
I am using CDT in Eclipse 3.5.2 Galileo in Ubuntu.
My eclipse's indexer doesn't work at times. By that I mean when I ctrl click a function it says Could not find symbol in index. Also, F3 button click results in the same error message. Actually most of the places it is not working and works in very few places.
I have seen some other versions of Eclipse where under File menu a menu item listed for Indexing. Like File->Indexer->Rebuild.... But in my File menu there is no such menu item for the Indexer.
Will the only way be to use some other release of Eclipse or am missing something? Any pointers regarding this would be helpful.
In my case nothing has worked and at last I did the following:
1) Close the project
2) Delete the project(do not check from disk option)
3) create new project with existing code(use the deleted project path)
4) Successfully indexed my c++ code
To add paths containing code to parse, follow these steps :
1. Right click on the project
2. Select Properties
3. Go to C/C++ General
4. Go to Path and Symbols
5. If the paths are missing, add paths.
To re-parse the code follow these steps :
1. Right click on the project
2. Select Index
3. Rebuild
If this doesn't work, then you are out of luck. c++ is very difficult language to parse.
If your indexer is stuck and it hangs for infinite time, you can delete the indexer related files of your project from .metadata. Make sure eclipse is not running in the meanwhile.
The .metadata directory is located as a hidden folder in the path of your workspace.
There you can navigate to:
<workspace_path>/.metadata/.plugins/org.eclipse.core.runtime/.settings/
Inside the .settings/ directory there are .prefs files which store the preferences of each project individually.
For example: org.eclipse.cdt.core.prj-test-project.prefs stores the preferences of the project test-project
Open this file with the text editor and remove all the lines starting with indexer. This will reset the indexer settings for this specific project to the default.
Alternatively, you can remove all the lines starting with indexer from org.eclipse.cdt.core.prefs; doing this will reset the indexer settings for the whole workspace.
I believe you can clear the index by running:
rm .metadata/.plugins/org.eclipse.jdt.core/*.index
And then restarting Eclipse. It will then rebuild its index.
This worked for me in a Java project, but I imagine its the same index for all (most?) project types.
Right click on the project.
Select New->Convert to a C++ Project.
Select your configuration. And then Next
Indexer will start indexing all the files.
For me this worked:
Right click and close the project
Open the project again
Right click and select Index->Rebuild
I hope it helps anybody.
You can try rebuilding the index.
Right-click on the project in Project View. Then Index -> Rebuild.
Here is the solution I used after Project->C++ Index->Rebuild failed. This trick avoid deleting your current project :
1) Copy the current project (Right click->Copy from Project Explorer)
2) Paste it (Right click->Paste from Project Explorer) and give the copy another name
3) The indexer should now start and index both projects
4) When indexation is complete, you can delete the copy
PS: Make sure your original project is an actual C++ Project or this will obviously not work.
Convert a project to C or C++ nature:
Right click on project: New > Convert to C/C++ Project
In "Convert to C or C++": Choose C/C++ Project
In "Project options": Check "Specify Project Type"
...Project Type: Choose "Makefile project"
...Toolchains: Gross GCC
I was having the same problem and it turns out that the index folder was owned by root (I must have run Eclipse as a root once for some reason) I reclaimed the project folder using sudo chown -R username projectfolderpath and problem solved.
Execute eclipse.exe -clean -refresh where the eclipse is installed.
Create a new C/C++ Project in Eclipse with Given Source code folder path. (Not with New Project based on existing workspace)
Above steps worked for me.
For me it was issue that when creating a project indexer was chosen as none. Deleted the project and while creating the project again I chose the indexer options as per my need "LINUX_GCC", then it worked for me
Just came across the same problem in my C++ ARM Cross GCC project. I'm developing on Windows, using Makefile and an Ubuntu Docker image with GNU ARM Embedded Toolchain to build the project.
The solution to get rid of the unresolved symbols, in my case, could be divided into two parts:
The CDT Arm Cross GCC Built-in Compiler Settings didn't have the path to the compiler.
In the Project Properties -> C/C++ General -> Preprocessor Include Paths -> Providers(tab) the path to the compiler must be provided.
Using the GNU ARM Embedded Toolchain, the entry for the Command to get compiler specs: I currently use is:
C:\GNU_Arm_Embedded_Toolchain\9-2020-q2-update\bin\arm-none-eabi-g++.exe ${FLAGS} ${cross_toolchain_flags} -E -P -v -dD "${INPUTS}"
Note: Yes, I am having installed the same toolchain on my Windows machine as I'm using in the Docker image.
To verify, that the call is correct, you can tick the Allocate console in the Console View, which will provide hlepful output to the Console. Also, in the Entries tab, when you unroll the CDT Arm Cross GCC Built-in Compiler Settings you should see the includes and symbols included.
Missing symbol in the Project Properties -> C/C++ General -> Paths and Symbols menu.
As I have my defines in the Makefile, I forgot to add the define of my MCU also here.
Hope this helps to someone! :)
For the most part, the other answers tackle the situation wherein one "had" a working index earlier and things have gone astray for some reason.
On the other hand, I faced a problem wherein I needed to install everything from scratch (eclipse, workspace, c++ project etc.) and the indexing just wouldn't work. I finally found the solution here: https://www.eclipse.org/forums/index.php/t/1109004/
The key inputs from the above page are:
You need to setup include paths for the Indexer just as you would need
to for the compiler. The Indexer and compiler are completely independent.
The Indexer include paths are set by
Project -->Properties --> C/C++ General --> Preprocessor Include Paths, Macros etc. --> Entries tab --> CDT UserSettings Entries ...
and
You could try using
Project --> Properties --> C/C++ General --> Paths and Symbols
That's supposed to merge telling the compiler and Indexer
in one place.
However, this latter part of the suggestion did not work for me.
for example I need to include a header
#include <OpenGL/glext.h>
while it is actually a header file glext.h under OpenGL.framework/Headers/.
Therefore it is no way to give eclipse a physical path about "OpenGL/glext.h", and I always get unresolved inclusion warning.
I can still build and run them (with managed makefile project) but it is impossible to browse the functions or definitions from those "resolved" header files.
is there any solution?
While not ideal, my solution to this has been to create a folder "/Developer/Framework Headers" (though the name isn't important), and link from e.g. "/System/Library/Frameworks/Foo.framework/Headers" to "Foo" under said folder. Then in Eclipse I add "/Developer/Framework Headers" to a project's includes.
I say not ideal because apart from having to create links for the frameworks you need and add an include to each project, Eclipse seems to have trouble in certain cases such as nested frameworks (e.g. CoreGraphics beneath ApplicationServices), but YMMV.
Yes there is one. Right click on the project in "Project Explore" window and click on the "property". In there Open "C/C++ General" column and choose "Path and symbols". Now you see all of the include library path for this project. If your using C then add the OpenGL library into GNU C, or if you use C++ then add it into GNU C++. Unfortunately you have to do this for every new project. I have been searching for a while how to do this by default but nothing really useful. Hope this help you get rid of those annoying yellow wave lines.
Since current Eclipse CDT releases don't perform sub-framework header inclusion correctly, you can avoid sub-framework problems (like those generated by the CoreServices header files) by creating symbolic links to the include directories of each sub-framework. I elaborated on this subject, which stems from danhan answer on this question, in this blog post.
In order to automate this process, I've created a Z shell script which automates this process and creates the symlink to the specified frameworks' header directory, together with the links to the include directory of each one of their sub-frameworks. The script can be found in this GitHub repository.
Hope this helps.