This change adds an optional argument to `genArchVals` that allows client code to override the backend translation behavior of `MacawArchStmtExtension`s on a statement-by-statement basis. The new argument has type `Maybe (MacawArchStmtExtensionOverride arch)`, where `MacawArchStmtExtensionOverride` is a function that takes a statement and a crucible state, and returns an optional tuple containing the value produced by the statement, as well as an updated state. Returning 'Nothing' indicates that the backend should use its default handler for the statement.
Client code that wishes to maintain the existing default behavior in all cases can simply pass `Nothing` for the new argument to `genArchVals`.
This cleanup consolidates the interface to macaw symbolic into two (and a half)
modules:
- Data.Macaw.Symbolic for clients who just need to symbolically simulate
machine code
- Data.Macaw.Symbolic.Backend for clients that need to implement new
architectures
- Data.Macaw.Symbolic.Memory provides a reusable example implementation of
machine pointer to LLVM memory model pointer mapping
Most functions are now documented and are grouped by use case. There are two
worked (compiling) examples in the haddocks that show how to translate Macaw
into Crucible and then symbolically simulate the results (including setting up
all aspects of Crucible). The examples are included in the symbolic/examples
directory and can be loaded with GHCi to type check them.
The Data.Macaw.Symbolic.Memory module still needs a worked example.
There were very few changes to actual code as part of this overhaul, but there
are a few places where complicated functions were hidden behind newtypes, as
users never need to construct the values themselves (e.g., MacawArchEvalFn and
MacawSymbolicArchFunctions). There was also a slight consolidation of
constraint synonyms to reduce duplication. All callers will have to be updated.
There is also now a README for macaw-symbolic that explains its purpose and
includes pointers to the new haddocks.
This commit also fixes up the (minor) breakage in the macaw-x86-symbolic
implementation from the API changes.
