We now emit `RegularSwitch` node type creating the vector containing the
case values by inspecting the actual values of the `ConstantInt` in the
IR.
Due to the introduction of weaving, we can have a cascade of switches,
and in this case the top switch should bring to a certain weaving switch
for multiple values of the case label.
For this reason, switch case are now represented by sets, which are
usually populated by a single value, but in presence of a weaving
switches they can represent the fact that for each value contained in
the set we must take a certain case label.
The backend of the decompiler has been updated to reflect this change,
in order to emit all the values for a certain `CaseSet` in `or` if the
size of the seat is greater than 1.
Replicate the changes made by this commit
f2a0df309f78e1b5d7c5f81ada5110523644559e perfomed by Pietro on the
branch containing the development fixes for `revng-c`.
Added a new attribute for the `ContinueNode`, which tells if a
`ContinueNode` should be considered implicit. An implicit continue node
means that it can be dropped without it altering the semantics of the
code (e.g., when the `continue` is the last statement inside the body of
a cycle).
This attribute enables us to avoid directly dropping the continue node,
which would also cause the computation attached to this node to be
dropped, also in the output of the decompiler pass.
We now check if the ASTNode of the `else` branch for which we try to
obtain a compound statement is non existing (`nullptr`), and in such
case we emit an ad-hoc if statement which does not have the else part.
Handle the emission of variadic functions (such as the
`indirect_handler` helper function) both in regards if declaration and
definition.
Handle also `undef` values in calls to the `indirect_handler` function.
`BasicBlockNode` and `RegionCFG` classes are now template classes. This
means that the `BasicBlockNode` class can be used as a generic wrapper
for any type of object in the original graph (it is usually used to wrap
a `llvm::BasicBlock *` for decompilation purposes, but in tests it can
be used to wrap a `DotNode` object) that implementes `GraphTraits`.
Removed the computation of the information contained in the
`NDuplicates` prevously done in the `MarkForSerialization` pass, since
the information is now precomputed in the `RestructureCFG` pass and
exposed with a dedicated method.
Moved a lot of passes that apply optimizations on the AST in the
decompilation pass.
All the optimization functions are now in a dedicated file
(`CDecompilerBeautify.cpp`) and the only function used as interface with
the `CDecompilerAction` pass is the `beautifyAST` function.
This means that now the simplifications will be applied on the already
flattened AST.
Some basic transformations have been left in the `RestructureCFG` pass,
to avoid having an AST of poor quality as output of the pass.
Pietro Fezzardi