This fixes a subtle bug in GenericGraph. Basically, if the label of an
Edge was the Empty data structure, whose `operator==` always returns
`true`, the comparison between edges was broken.
Before this commit, it could happen that some duplicated dummy node
(used to mark backedges) could be left lingering in wrong regions when
collapsing a regions, if they were first iteration outlined.
This commit fixes the problem, by collecting them and letting
`updateNodes` take care of them, removing them from the containing
region and all its parents.
Over time, these tags have shifted to basically coincide with the Copy
and Assign tags. There's no need for them anymore they just make the
code more verbose and less straightforward.
Before this commit the `hasSideEffects` helper function was only a stub,
that was never updated to be aware of recent FunctionTags representing
custom opcodes without side-effects.
This commit updates it, so that now it is less aggressive in marking
harmless stuff as side-effectful.
Various parts of revng replace `llvm::GlobalVariable`s representing CSVs
with Allocal/Load/Store. In particular, these are PromoteCSV,
RootAnalyzer and PromoteGlobalToLocalVars.
Before this commit, those places were sloppy when replacing CSVs with
Alloca/Load/Store, and did that iterating on a container sorted by
pointers. This caused Alloca/Load/Store to be emitted in different order
accross runs, which in turn caused more non-determinism down the
pipeline.
This commit fixes the non-deterministic behavior, sorting CSVs based on
their names, which should always be present and deterministic.
This commit moves stuff around to enforce complete information being
present by the time the "Internal" assembly output is ready.
Because of that, the "Internal" format needed to change, now it uses
tag representation close to PTML as opposed to the one close to LLVM's
used before now.
Various improvements to the debug graphs for `restructure-cfg` and
`beautify`:
- Normalize casing and syntax of debug graphs.
- Improve the graph folders name and layout.
- Implement `CFGDumper` and `ASTDumper` for when we need a serialization
with incremental indexes.
- Remove old and stale graph serializations.
Do not re-enqueue conditional nodes a for combing, when duplicating a
conditional.
This can be done in such way, thanks to the property that we process
conditional nodes in postorder. Therefore, if conditional node A causes
the duplication of, say, node B, we have the guarantee that such node B
has already been processed by the combing. Therefore, the clone of node
B, say node B', should not be reprocessed for combing.
Alessandro Di Federico