In a clang plugin, how do you see whether there was an error compiling the translation unit?

Question

I want my clang plugin to not actually do anything if there was an error compiling the code for the AST my plugin is going to run on.

However, I can't figure out what object contains the list of errors generated during compilation.

Is there either a boolean query for whether there was an error or a list API for getting all the errors (or all diagnostics) generated during the TU compilation?

Thank you.

Answer 1

I eventually figured out a way to get the error count from a CompilerInstance object:

auto & ast_context = compiler_instance.getASTContext();
auto & diagnostics_engine = ast_context.getDiagnostics();
auto diagnostic_consumer = diagnostics_engine.getClient();
auto error_count = diagnostic_consumer->getNumErrors();
if (error_count > 0) {
    llvm::report_fatal_error("Errors during compilation, plugin aborting");
}

I don't know if this is the best way, but it is working for me when I put the above code in the onStartOfTranslationUnit of my class I derive from ast_matchers::MatchFinder::MatchCallback.