This is another PR towards the goal of getting Z3 to compile cleanly
when included via FetchContents into clang-tidy, which uses a pretty
strict set of warnings.
This is a second version of https://github.com/Z3Prover/z3/pull/9957. I
address @NikolajBjorner 's comments about not changing the semicolons
after macro invocations, because some editors work better with them
present. It now, to the best of my ability, only deletes semis:
* after the closing brace of namespace decl.
* after the closing brace of an extern "C" decl.
* after a function definition.
This PR is very large, but it consists entirely of deletions of
semicolons in these situations.
(If there was a way to update the previous PR, which had been closed,
and that is preferable, please let me know. I couldn't figure it out.)
It is not unlike other fuzz bugs: it exercises some behavior that applications are unlikely to expose. In this case, a rule body expanded into a conjunction with more than 1M formulas (with a lot of repetition). The original rule representation assumed silently that the number of constraints in a body would fit within 20 bits, but reality allowed bodies with as many as 2^{32} - 1 constraints.
So "minimizing" the bug as @agurfinkel asks for seems not to make too much sense.
Just running the samples in debug mode points to the root cause.
Since fuzz bugs are not from applications and fuzz tools have the potential for creating a large number of issues, I find it reasonable to push some basic pro-active asks on filers:
- reproduce bug in debug builds to assess whether a debug assert triggers.
- minimize or keep it simpler when possible (in this case it does not apply)
- perform basic diagnostics/triage. I am basically asking to push this part of the work on to the fuzzer. Otherwise, addressing random bugs doesn't scale. Triaging should have pointed to the root cause.
Now, there tends to be something to learn from bugs. In this case, the question was: "can we avoid constraints with duplications"? In particular, it points to a basic inefficiency of extracting conjunctions (and disjunctions). The function didn't deduplicate. So I added deduplication into this function. It is used throughout z3 code base so could expose latent issues. We will see.
This patch adds an instruction to the datalog interpreter and
constructs a new AST node for min aggregation functions.
The compiler is currently still work in progress and depends on
changes made to the handling of simple joins and the preprocessor.
Signed-off-by: Alex Horn <t-alexh@microsoft.com>
