ACID: A Debugger Built from a Language

ACID is an unusual source-level symbolic debugger for Plan 9. It is implemented as a language interpreter with specialized primitives that provide debugger support. Programs written in the language manipulate one or more target processes; variables in the language represent the symbols, state, and resources of those processes. This structure allows complex interaction between the debugger and the target program and provides a convenient method of parameterizing differences between machine architectures. Although some effort is required to learn the debugging language, the richness and flexibility of the debugging environment encourages new ways of reasoning about the way programs run and the conditions under which they fail.