LLVM Error: 'Unknown target triple' – TargetInfo component

Goal: Configure meaningful diagnostics

We want to keep only critical errors while suppressing routine warnings, using LLVM’s DiagnosticHandler API.

Constraints: The handler must not swallow fatal errors such as the documented “LLVM Error: 'Unknown target triple'” emitted by TargetInfo when an invalid triple is passed to TargetMachine::createTargetMachine.

Unresolved behavior: When PassManagerBase::run encounters a fatal error during a pass, the public documentation does not specify whether the entire pipeline should abort or continue with a partial result for all pass manager variants.

1. Is there a documented policy that dictates whether PassManagerBase aborts the pipeline or continues after a fatal error?
2. How can a custom DiagnosticHandler be configured to guarantee that such fatal errors are always reported, even when other diagnostics are suppressed?
3. Are there any TargetOptions or PassManager settings that influence this abort/continue decision?