Extension cpp lsp

[Aldenysq]

No description provided.

[petervdonovan]

Maven Tycho is not happy:

Error:  Failed to execute goal org.eclipse.tycho:tycho-compiler-plugin:2.6.0:compile (default-compile) on project org.lflang.diagram: Compilation failure: Compilation failure: 
Error:  /home/runner/work/lingua-franca/lingua-franca/org.lflang.diagram/src/org/lflang/diagram/lsp/CppLanguageServer.java:[14] 
Error:  	import com.fasterxml.jackson.databind.ObjectMapper;
Error:  	       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error:  Access restriction: The type 'ObjectMapper' is not API (restriction on classpath entry '/home/runner/.m2/repository/p2/osgi/bundle/com.fasterxml.jackson.core.jackson-databind/2.13.2.v20220426-1653/com.fasterxml.jackson.core.jackson-databind-2.13.2.v20220426-1653.jar')

I think this makes no sense. I'm pretty sure ObjectMapper is API.

Is there a way we can exclude this code from the Tycho build? Maybe in the same way as the way we exclude Kotlin? Epoch does not use this code.

[petervdonovan]

    try {
        if (!initialized) {
            CppLanguageServer.init();
            initialized = true;
        }
        return CppLanguageServer.hoverRequest(params);
    } catch (IndexOutOfBoundsException e) {
        return IHoverService.EMPTY_HOVER;  // Fail silently
    }

The old code which got deleted in this PR does "Fail silently," as it says, which is of course very bad. However, I want to keep it around (temporarily, until we move away from Xtext). See lf-lang/vscode-lingua-franca#63 (and the comment about the "hacky little patch") for background

[petervdonovan]

Oh, wait, never mind. If we don't use the default hover method, we don't have the IndexOutOfBoundsException from the framework, so that comment was not exactly right. But we do use the default hover method if we are not hovering over C++ code. So actually, the right thing to do is to use the old hacky thing only if we are not hovering over C++.

Edit: Actually, I should just stop talking and clarify what I mean when I have my wits about me and have read all the other code. You can disregard what I wrote.

[Aldenysq]

Commit mostly works except it highly depends on a user using "lf build" all the time, but not pressing Command+S which saves a file. If a user presses Command+S, the current file that a user is working on does not produce any output anymore (I assume the issue is somewhere where the file is closed and reopened).
Also, if some src-gen directory is deleted, feature stops working.
Steps to reproduce:

• need to install clang
• compile the project
• Open .lf file, it should start building once the file is open
• Then the feature should work,
• 1. try deleting src-gen files and rebuilding again
• 2. try pressing command+s, in both cases it stops working.
     There is also a bug that if a user has backslash in their code, the output is not consistent, but it is due to not proper serialization when sending json request and will be fixed soon. I should also think about other special characters that might appear in code that would not properly interact with json request.