Android – how to list GNU C in preferences

I have a mixed Java / C project. I want to develop it on the new PC. It uses opencv graphics library. Everything is normal on the original PC, but when I copy the project to the new PC, I get an error, indicating that eclipse does not know whether my compiler exists. For example, next to the line using namespace STD; It says the symbolic Standard cannot be solved

Then I loaded a sample project from the opencv library, including Java and C elements. It compiled and ran perfectly. Then I looked at the properties of the sample project and noticed that "GNU C" and "GNU C" are listed as languages in the "includes" tab (see the figure below). In the corresponding parts of the preferences of possible non compiled projects, it only represents "C, CPP" . the tag set is also different. I suspect this is a clue to error, but I don't know what determines the language list or displayed tags in this box. Do you have any ideas?

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resolvent:

This is because the wrong project type and tool chain were selected when creating / importing the project. I don't know how to get the "other tool chains" option in the tool chain editor

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Follow these steps:

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Then verify that GNU C and GNU C options are listed in the path and symbol