Related
The error is as above. I have what should be all the necessary files include in the eclipse project:
/usr/include/c++/4.6
/usr/include
/usr/include/linux
/usr/local/include
etc.
I tried std::cout and using namespace std; cout but it still says unresolved.
I have imported iostream and cstdlib.
Also, I'm on Ubuntu 12.04 with eclipse 3.7.2.
Code snippet:
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include "XPLMDisplay.h"
#include "XPLMGraphics.h"
int XPluginStart(char * outName, char * outSig, char * outDesc) {
/* ... */
std::cout << "test" << std::endl;
/* ... */
}
using namespace std;
UPDATE: I had created the eclipse project from existing code. Creating a new c++ project fixes it. I'll accept an answer that explains what setting in the existing project could cause this (so I don't have to cut & paste all my projects).
Most likely you have some system-specific include directories missing in your settings which makes it impossible for indexer to correctly parse iostream, thus the errors. Selecting Index -> Search For Unresolved Includes in the context menu of the project will give you the list of unresolved includes which you can search in /usr/include and add containing directories to C++ Include Paths and Symbols in Project Properties.
On my system I had to add /usr/include/c++/4.6/x86_64-linux-gnu for bits/c++config.h to be resolved and a few more directories.
Don't forget to rebuild the index (Index -> Rebuild) after adding include directories.
To get rid of symbol warnings you don't want, first you should understand how Eclipse CDT normally comes up with unknown symbol warnings in the first place. This is its process, more or less:
Eclipse detects the GCC toolchains available on the system
Your Eclipse project is configured to use a particular toolchain
Eclipse does discovery on the toolchain to find its include paths and built-in defines, i.e. by running it with relevant options and reading the output
Eclipse reads the header files from the include paths
Eclipse indexes the source code in your project
Eclipse shows warnings about unresolved symbols in the editor
It might be better in the long run to fix problems with the earlier steps rather than to override their results by manually adding include directories, symbols, etc.
Toolchains
If you have GCC installed, and Eclipse has detected it, it should list that GCC as a toolchain choice that a new C++ project could use, which will also show up in Window -> Preferences -> C/C++ -> New CDT Project Wizard on the Preferred Toolchains tab's Toolchains box on the right side. If it's not showing up, see the CDT FAQ's answer about compilers that need special environments (as well as MinGW and Cygwin answers for the Windows folk.)
If you have an existing Eclipse C++ project, you can change the associated toolchain by opening the project properties, and going to C/C++ Build -> Tool Chain Editor and choosing the toolchain you want from the Current toolchain: pulldown. (You'll have to uncheck the Display compatible toolchains only box first if the toolchain you want is different enough from the one that was previously set in the project.)
If you added a toolchain to the system after launching Eclipse, you will need to restart it for it to detect the toolchain.
Discovery
Then, if the project's C/C++ Build -> Discovery Options -> Discovery profiles scope is set to Per Language, during the next build the new toolchain associated with the project will be used for auto-discovery of include paths and symbols, and will be used to update the "built-in" paths and symbols that show up in the project's C/C++ General -> Paths and Symbols in the Includes and Symbols tabs.
Indexing
Sometimes you need to re-index again after setting the toolchain and doing a build to get the old symbol warnings to go away; right-click on the project folder and go to Index -> Rebuild to do it.
(tested with Eclipse 3.7.2 / CDT 8)
Thanks loads for the answers above. I'm adding an answer for a specific use-case...
On a project with two target architectures each with its own build configuration (the main target is an embedded AVR platform; the second target is my local Linux PC for running unit tests) I found it necessary to set Preferences -> C/C++ -> Indexer -> Use active build configuration as well as to add /usr/include/c++/4.7, /usr/include and /usr/include/c++/4.7/x86_64-linux-gnu to Project Properties -> C/C++ General -> Paths and Symbols and then to rebuild the index.
I tried the marked solution here first. It worked but it is kind hacky, and you need to redo it every time you update the gcc. I finally find a better solution by doing the followings:
Project -> Properties -> C/C++ General -> Preprocessor Include Paths, Macros, etc.
Providers -> CDT GCC built-in compiler settings
Uncheck Use global provider shared between projects (you can also modify the global provider if it fits your need)
In Command to get compiler specs, add -std=c++11 at the end
Index->Rebuild
Voila, easy and simple. Hopefully this helps.
Note: I am on Kepler. I am not sure if this works on earlier Eclipse.
I am using Ubuntu 12.04 / Eclipse 4.2.1 / CDT 8.1.1 and I used to have the same problem for quite some time: importing a C++ project from SVN would cause these annoying "Unresolved inclusion" errors and I would instead have to create a new project and copy the files in there as a work-around (still partial, since SVN functionality would not be there!).
At last, I have just found a simple, satisfactory solution:
Go to Project -> Properties -> C/C++ General -> Preprocessor Include Paths, Macros etc. -> Providers and check Enable language settings providers for this project.
Restart Eclipse.
Hopefully that already does the trick.
I had a similar problem with *std::shared_ptr* with Eclipse using MinGW and gcc 4.8.1. No matter what, Eclipse would not resolve *shared_ptr*. To fix this, I manually added the __cplusplus macro to the C++ symbols and - viola! - Eclipse can find it. Since I specified -std=c++11 as a compile option, I (ahem) assumed that the Eclipse code analyzer would use that option as well. So, to fix this:
Project Context -> C/C++ General -> Paths and Symbols -> Symbols Tab
Select C++ in the Languages panel.
Add symbol __cplusplus with a value of 201103.
The only problem with this is that gcc will complain that the symbol is already defined(!) but the compile will complete as before.
For me it helped to enable the automated discovery in Properties -> C/C++-Build -> Discovery Options to resolve this problem.
I simply delete all error in the buttom: problem list.
then close project
and reopen project
clean project
build all
run
then those stupids errors go.
If all else fails, like it did in my case, then just disable annotations. I started a c++11 project with own makefile but couldn't fix all the problems. Even if you disable annotations, eclipse will still be able to help you do some autocompletion. Most importantly, the debugger still works!
I had the same issue using Eclipse CDT (Kepler) on Windows with Cygwin installed. After pointing the project properties at every Cygwin include I could think of, it still couldn't find cout.
The final missing piece turned out to be C:cygwin64\lib\gcc\x86_64-pc-cygwin\4.8.2\install-tool\include.
To sum up:
Right click on the project
Choose Properties
Navigate to C/C++ General > Paths and Symbols > Includes tab
Click Add...
Click File system...
Browse to the location of your Cygwin lib\gcc\x86_64-pc-cygwin\4.8.2\install-tool\include
Click OK
Here is what my project includes ended up looking like when it was all said and done:
You guys are looking under the wrong section.
I realized the difference when I installed in Linux after recently getting frustrated with Windows and the difference was immediately apparent.
In the new setup I have an includes folder in a projected that I created out of existing source. I can expand this and see a ton of includes; however, I cannot add to them.
This lead me to a hunt for where these files were being listed.
They're listed under the Project Properties > C/C++ General > Preprocessor Includes > GNU C++
CDT GCC Built-in Compiler Settings [Shared]
Under that is a ton of includes.
These settings are set by the toolchain you've selected.
I have created the Makefile project using cmake on Ubuntu 16.04.
When created the eclipse project for the Makefiles which cmake generated I created the new project like so:
File --> new --> Makefile project with existing code.
Only after couple of times doing that I have noticed that the default setting for the "Toolchain for indexer settings" is none.
In my case I have changed it to Linux GCC and all the errors disappeared.
Hope it helps and let me know if it is not a legit solution.
Cheers,
Guy.
I had this happen after updating gcc and eclipse on ArchLinux. What solved it for me was Project -> C/C++ Index -> Rebuild.
Just adding yet another bit of advice after trying a bunch of stuff myself and it not working....
I had GCC installed and the path to the includes set correctly. Had the std error as well, and couldn't get anything working for cout (and I suspect anything in the SL...)
Took me awhile to realize that g++ wasn't installed - gcc was but not g++. So just do:
sudo apt-get install g++
Restart eclipse. Assuming above mentioned details about gcc & paths to includes are fine, you should be okay now...
mine was bit easy to fig out right click >run as>run configration
check boxes include system lib,inherited mains
I have a Windows8 machine with mingw installed in c:\mingw
Eclipse does successfully compile programs, but it considers lines to contain errors that are fine when compiled. Eclipse is not finding the libraries itself.
When I first build a project in eclipse with the CDT components install, it shows errors on every #include and every line using an object.
Example:
#include <iostream>
using namespace std;
int main() {
cout << "hello\n";
}
The above code shows errors on the include, the using and the cout << line.
I can get rid of the errors by clicking:
project->properties C++/General Preprocessor Include
Then on the providers tab, I can check off "CDT Build output parser" and fix the mistakes as described by the first answer below, which I am upchecking. But this only works for the project. I have to do this every time. How can I get eclipse to simply accept standard C++ EVERY TIME I build a new project without reconfiguring each project?
I have been able to stop errors on the includes by going into project settings and adding the directories:
c:/bin/mingw/lib/gcc/include
...
That leaves the errors on lines using the objects.
#include <iostream>
#include <string>
#include <regex>
using namespace std;
int main() {
string s = "this is a test.";
regex e("est");
smatch m;
The line with regex still shows an error: "type regex could not be resolved"
even though the code compiles and the regex include is recognized.
Additionally, on a different machine running windows 8.1 with Mingw installed, eclipse will not debug. Is there some document on how to connect Eclipse CDT to the library?
While you obviously successfully compile the code with gcc from within Eclipse, Eclipse has its own built-in C++ parser and you need to separately let it know that you are using C++11.
Add the -std=c++11 option to the CDT GCC Builtin Compiler Settings under Project propierties -> C/C++ General -> Preprocessor Include Paths, the compiler specs should look similar to this:
${COMMAND} -E -P -v -dD ${INPUTS} -std=c++11
UPDATE. Please read Setting Up Include Paths and Macros for C/C++ Indexer to understand how CDT automatic discovery of include paths and preprocessor symbols (aka Scanner Discovery) for supported tool chains is applicable to you.
The gist is that the CDT uses the Language Settings Providers to find include paths and preprocessor symbols. And Language Settings Providers can be configured on project properties page "Preprocessor Include Paths, Macros, etc."
Once you have proper settings you can make them a template workspace and just copy the template workspace over for your new projects, or alternatively have a script that will set up just the relevant settings. Also see: Setting preferences for all Eclipse workspaces.
I have had the same problem. Eclipse underlined like an error a regex keyword, but project was built without errors. I chose a Language Dialect as "ISO C++1y (-std=c++1y)" in Properties->C/C++ Build->GCC C++ Compiler->Dialect Language Standart
Been a while, but adding in case someone else finds this answer as I did.
I had what appeared to be this issue but it turned out that while I had installed MinGW, eclipse still expected me to have installed cygwin. Go to project properties > C/C++ Build > Tool Chain Editor > Current Toolchain and select the appropriate option.
Not sure why it defaults the setting to a toolchain it can't find.
Since I upgraded from Eclipse Indigo to Juno (on Ubuntu 12.04), I've been having the problem where it shows "unresolved inclusion" errors for standard libraries (e.g. next to #include <iostream> and #include <vector>, etc.), although the program builds and runs fine (using g++). This only occurs in new projects created with Juno, not old ones from Indigo in my workspace.
Thanks to several other SO questions (see below*), I was able to trace the source of the problem to the absence of the "built-in values" in a project's Properties > C/C++ General > Paths and Symbols > Includes tab:
/usr/include/c++/4.6
/usr/include/c++/4.6/x86_64-linux-gnu
/usr/include/c++/4.6/backward
/usr/lib/gcc/x86_64-linux-gnu/4.6/include
/usr/lib/gcc/x86_64-linux-gnu/4.6/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
are present when the "Show built-in values" checkbox is ticked in my old Indigo projects that didn't have this problem, but are absent in my new projects created with Juno. Sure enough, if I add these seven directories manually to the Includes tab in a project's settings, the problem disappears. But I don't want to have to do this manually for every new project I create. Is there a reason this is no longer the default in Juno, and is there a way to restore it?
*Other SO questions with similar issues I have consulted but did not solve my problem:
Eclipse 3.7.0 Indigo with CDT shows many false compilation errors: I thought Erzsébet Geréb's answer would be my solution -- in Juno, if I create a new C++ project with "Project type" as one of the categories under "GNU Autotools" instead of "Executable," the built-in directories are there. (In Indigo, there's no GNU Autotools category. If I created it in Indigo as an empty or Hello World project under "Executable," those directories are there, but they're not if I do it that way in Juno -- I have to pick an option under "GNU Autotools.") But then, with a "GNU Autotools" project, when I go to the project's Properties > C/C++ Build > Settings, the "Tool Settings" tab is no longer present and I am unable to add include paths for the GCC C++ Compiler and libraries for the GCC C++ Linker, which I need to do because many of my C++ projects use OpenCV libraries.
"Unresolved inclusion" error with Eclipse CDT for C standard library headers: Told me how to add the include paths manually, but not how to have the built-in ones added by default
error , Symbol 'vector' could not be resolved: Cleaning ~/.eclipse/ and rebuilding index didn't help.
Eclipse CDT Builtin Include Directories: Discovery Options are set the same as my projects that do work properly.
eclipse CDT 8.01 - default paths (libstdc,libstdc++) totally disappeared in 'includes' directory
Eclipse CDT indexer lost after system update: Doesn't solve the problem for all new projects.
Please
Open the Eclipse Preferences dialog (Windows | Preferences).
Open C++ | Build | Settings.
Open the Discovery tab.
Select the built-in compiler settings entry.
Press the Clear Entries button.
Afterwards eclipse should request the defaults again from the compiler.
On Arch Linux I had to do this after each GCC version change, because in that case the locations for the defaults changed as the version is encoded in the folder name, and eclipse does not notice this.
FWIW:
I found that after importing a project from another computer, I was not getting any thing showing up under the "Includes" section of my project in the Project Explorer. To fix this, I needed to delete the folder /workspace/project/.settings/. For me it only had one file (language.settings.xml).
Then everything was back to normal.
The error is as above. I have what should be all the necessary files include in the eclipse project:
/usr/include/c++/4.6
/usr/include
/usr/include/linux
/usr/local/include
etc.
I tried std::cout and using namespace std; cout but it still says unresolved.
I have imported iostream and cstdlib.
Also, I'm on Ubuntu 12.04 with eclipse 3.7.2.
Code snippet:
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include "XPLMDisplay.h"
#include "XPLMGraphics.h"
int XPluginStart(char * outName, char * outSig, char * outDesc) {
/* ... */
std::cout << "test" << std::endl;
/* ... */
}
using namespace std;
UPDATE: I had created the eclipse project from existing code. Creating a new c++ project fixes it. I'll accept an answer that explains what setting in the existing project could cause this (so I don't have to cut & paste all my projects).
Most likely you have some system-specific include directories missing in your settings which makes it impossible for indexer to correctly parse iostream, thus the errors. Selecting Index -> Search For Unresolved Includes in the context menu of the project will give you the list of unresolved includes which you can search in /usr/include and add containing directories to C++ Include Paths and Symbols in Project Properties.
On my system I had to add /usr/include/c++/4.6/x86_64-linux-gnu for bits/c++config.h to be resolved and a few more directories.
Don't forget to rebuild the index (Index -> Rebuild) after adding include directories.
To get rid of symbol warnings you don't want, first you should understand how Eclipse CDT normally comes up with unknown symbol warnings in the first place. This is its process, more or less:
Eclipse detects the GCC toolchains available on the system
Your Eclipse project is configured to use a particular toolchain
Eclipse does discovery on the toolchain to find its include paths and built-in defines, i.e. by running it with relevant options and reading the output
Eclipse reads the header files from the include paths
Eclipse indexes the source code in your project
Eclipse shows warnings about unresolved symbols in the editor
It might be better in the long run to fix problems with the earlier steps rather than to override their results by manually adding include directories, symbols, etc.
Toolchains
If you have GCC installed, and Eclipse has detected it, it should list that GCC as a toolchain choice that a new C++ project could use, which will also show up in Window -> Preferences -> C/C++ -> New CDT Project Wizard on the Preferred Toolchains tab's Toolchains box on the right side. If it's not showing up, see the CDT FAQ's answer about compilers that need special environments (as well as MinGW and Cygwin answers for the Windows folk.)
If you have an existing Eclipse C++ project, you can change the associated toolchain by opening the project properties, and going to C/C++ Build -> Tool Chain Editor and choosing the toolchain you want from the Current toolchain: pulldown. (You'll have to uncheck the Display compatible toolchains only box first if the toolchain you want is different enough from the one that was previously set in the project.)
If you added a toolchain to the system after launching Eclipse, you will need to restart it for it to detect the toolchain.
Discovery
Then, if the project's C/C++ Build -> Discovery Options -> Discovery profiles scope is set to Per Language, during the next build the new toolchain associated with the project will be used for auto-discovery of include paths and symbols, and will be used to update the "built-in" paths and symbols that show up in the project's C/C++ General -> Paths and Symbols in the Includes and Symbols tabs.
Indexing
Sometimes you need to re-index again after setting the toolchain and doing a build to get the old symbol warnings to go away; right-click on the project folder and go to Index -> Rebuild to do it.
(tested with Eclipse 3.7.2 / CDT 8)
Thanks loads for the answers above. I'm adding an answer for a specific use-case...
On a project with two target architectures each with its own build configuration (the main target is an embedded AVR platform; the second target is my local Linux PC for running unit tests) I found it necessary to set Preferences -> C/C++ -> Indexer -> Use active build configuration as well as to add /usr/include/c++/4.7, /usr/include and /usr/include/c++/4.7/x86_64-linux-gnu to Project Properties -> C/C++ General -> Paths and Symbols and then to rebuild the index.
I tried the marked solution here first. It worked but it is kind hacky, and you need to redo it every time you update the gcc. I finally find a better solution by doing the followings:
Project -> Properties -> C/C++ General -> Preprocessor Include Paths, Macros, etc.
Providers -> CDT GCC built-in compiler settings
Uncheck Use global provider shared between projects (you can also modify the global provider if it fits your need)
In Command to get compiler specs, add -std=c++11 at the end
Index->Rebuild
Voila, easy and simple. Hopefully this helps.
Note: I am on Kepler. I am not sure if this works on earlier Eclipse.
I am using Ubuntu 12.04 / Eclipse 4.2.1 / CDT 8.1.1 and I used to have the same problem for quite some time: importing a C++ project from SVN would cause these annoying "Unresolved inclusion" errors and I would instead have to create a new project and copy the files in there as a work-around (still partial, since SVN functionality would not be there!).
At last, I have just found a simple, satisfactory solution:
Go to Project -> Properties -> C/C++ General -> Preprocessor Include Paths, Macros etc. -> Providers and check Enable language settings providers for this project.
Restart Eclipse.
Hopefully that already does the trick.
I had a similar problem with *std::shared_ptr* with Eclipse using MinGW and gcc 4.8.1. No matter what, Eclipse would not resolve *shared_ptr*. To fix this, I manually added the __cplusplus macro to the C++ symbols and - viola! - Eclipse can find it. Since I specified -std=c++11 as a compile option, I (ahem) assumed that the Eclipse code analyzer would use that option as well. So, to fix this:
Project Context -> C/C++ General -> Paths and Symbols -> Symbols Tab
Select C++ in the Languages panel.
Add symbol __cplusplus with a value of 201103.
The only problem with this is that gcc will complain that the symbol is already defined(!) but the compile will complete as before.
For me it helped to enable the automated discovery in Properties -> C/C++-Build -> Discovery Options to resolve this problem.
I simply delete all error in the buttom: problem list.
then close project
and reopen project
clean project
build all
run
then those stupids errors go.
If all else fails, like it did in my case, then just disable annotations. I started a c++11 project with own makefile but couldn't fix all the problems. Even if you disable annotations, eclipse will still be able to help you do some autocompletion. Most importantly, the debugger still works!
I had the same issue using Eclipse CDT (Kepler) on Windows with Cygwin installed. After pointing the project properties at every Cygwin include I could think of, it still couldn't find cout.
The final missing piece turned out to be C:cygwin64\lib\gcc\x86_64-pc-cygwin\4.8.2\install-tool\include.
To sum up:
Right click on the project
Choose Properties
Navigate to C/C++ General > Paths and Symbols > Includes tab
Click Add...
Click File system...
Browse to the location of your Cygwin lib\gcc\x86_64-pc-cygwin\4.8.2\install-tool\include
Click OK
Here is what my project includes ended up looking like when it was all said and done:
You guys are looking under the wrong section.
I realized the difference when I installed in Linux after recently getting frustrated with Windows and the difference was immediately apparent.
In the new setup I have an includes folder in a projected that I created out of existing source. I can expand this and see a ton of includes; however, I cannot add to them.
This lead me to a hunt for where these files were being listed.
They're listed under the Project Properties > C/C++ General > Preprocessor Includes > GNU C++
CDT GCC Built-in Compiler Settings [Shared]
Under that is a ton of includes.
These settings are set by the toolchain you've selected.
I have created the Makefile project using cmake on Ubuntu 16.04.
When created the eclipse project for the Makefiles which cmake generated I created the new project like so:
File --> new --> Makefile project with existing code.
Only after couple of times doing that I have noticed that the default setting for the "Toolchain for indexer settings" is none.
In my case I have changed it to Linux GCC and all the errors disappeared.
Hope it helps and let me know if it is not a legit solution.
Cheers,
Guy.
I had this happen after updating gcc and eclipse on ArchLinux. What solved it for me was Project -> C/C++ Index -> Rebuild.
Just adding yet another bit of advice after trying a bunch of stuff myself and it not working....
I had GCC installed and the path to the includes set correctly. Had the std error as well, and couldn't get anything working for cout (and I suspect anything in the SL...)
Took me awhile to realize that g++ wasn't installed - gcc was but not g++. So just do:
sudo apt-get install g++
Restart eclipse. Assuming above mentioned details about gcc & paths to includes are fine, you should be okay now...
mine was bit easy to fig out right click >run as>run configration
check boxes include system lib,inherited mains
I have locally forked (via hg clone) a C/C++ (Eclipse CDT) project and imported it into my Eclipse workspace. My editor window for the forked project now looks like this:
Clearly, these are not real errors, since the code builds correctly. Also, these errors are not marked in the original project from which this one was forked.
Why does Eclipse think there are errors in this source?
EDIT: Eclipse error messages when hovering over the "bugs" are, e.g., Type int64_t could not be resolved and symbol 'cout' could not be resolved.
EDIT: I've noticed that Eclipse usually shows a "folder" named includes in the project. It is missing for this project. How can I get it back?
Eclipse has to know the paths where to find the include files. This may be set using general eclipse settings or project by project.
For some reason it seems like the default paths are not set for your current project.
What you can do:
Open the project settings and go to C/C++ General -> Paths and Symbols (at least that is how it is called in my eclipse version) and fix the include directories.
Maybe it is enough to load the default configuration for that specific project. Maybe you have to set up your include pathes by yourself. On Unix / OS X this should usually be usr/include. On Windows I have no idea, but that should be easy to find out.
Afterwards it may be necessary that your rebuild your eclipse index (right click on your project, then index -> rebuild).
If that does not help please share a screenshot of the Paths and Symbols dialog of your project.
Also see the eclipse documentation on this topic.
I had to include
CDT Cross GCC Built-in Compiler Settings
CDT GCC Built in Compiler Settings [ Shared ]
in Properties for the project -> C/C++ General -> Preprocessor Include Paths, Macros etc. -> Providers
add this define in Eclipse to Project Properties->C/C++ General->Paths and Symbols
__STDC_FORMAT_MACROS
Rebuild your eclipse index. It will work.
This worked on Mac OS X Yosemite 10.10.5, Eclipse version Mars.1 Release (4.5.1):
Since the includes are usually discovered by Eclipse through the toolchain, check that you have an actual toolchain set (when I ran into this problem after importing a project, the toolchain was set to "No toolchain."):
Project -> Properties -> C/C++ Build -> Tool Chain Editor -> Current toolchain
If no toolchains appear in the dropdown, try unchecking "Display compatible toolchains only" and choosing a toolchain (I chose Cross GCC). When I saved the changes and re-opened the project properties to look at this field again, "Display compatible toolchains only" was automatically re-checked.
Then re-index the project:
Project -> C/C++ Index -> Rebuild
This solved the problem for me (the "pseudo-errors" disappeared, and the includes "folder" appeared under my project in the file system view).
Have you #included the correct files in your code? For std::cout it would be:
#include <iostream>
and for int64_t:
#include stdint.h