AFLGo Link-Time Instrumentation

include/Fuzzing/AFLGoLinker/ and lib/Fuzzing/AFLGoLinker/ implement the link-time instrumentation passes for AFLGo-style directed fuzzing.

Location: include/Fuzzing/AFLGoLinker/, lib/Fuzzing/AFLGoLinker/

Main passes:

• AFLGoDistanceInstrumentationPass instruments distance feedback.

• FunctionDistancePass injects function-level distance data.

• DAFLInstrumentationPass adds DAFL-specific instrumentation.

• DuplicateTargetRemovalPass and AFLGoTargetInjectionFixupPass clean up target metadata before final code generation.

Role in the pipeline:

• consume the analyses from Directed Fuzzing Analyses

• insert profile-guiding feedback at LTO time

• finalize target handling for directed greybox fuzzers

Operational notes

Use the linker passes with the distance and target facts generated for the same program revision. The cleanup passes run before final code generation so instrumentation observes a consistent set of target annotations. Validate the resulting bitcode or executable with a small corpus before interpreting distance feedback as a fuzzing-quality signal.

See also Fuzzing Support.