Aligned with the measures we had in D124674, this condition seems to be
unlikely.
Nevertheless, I've made some new measurments with stats just for this,
and data confirms this is indeed unlikely.
Differential Revision: https://reviews.llvm.org/D127190
Assume functions might recurse (see `reAssume` or `tryRearrange`).
During the recursion, the State might not change anymore, that means we
reached a fixpoint. In this patch, we avoid infinite recursion of assume
calls by checking already visited States on the stack of assume function
calls. This patch renders the previous "workaround" solution (D47155)
unnecessary. Note that this is not an NFC patch. If we were to limit the
maximum stack depth of the assume calls to 1 then would it be equivalent
with the previous solution in D47155.
Additionally, in D113753, we simplify the symbols right at the beginning
of evalBinOpNN. So, a call to `simplifySVal` in `getKnownValue` (added
in D51252) is no longer needed.
Fixes https://github.com/llvm/llvm-project/issues/55851
Differential Revision: https://reviews.llvm.org/D126560
Depends on D125892. There might be efficiency and performance
implications by using a lambda. Thus, I am going to conduct measurements
to see if there is any noticeable impact.
I've been thinking about two more alternatives:
1) Make `assumeDualImpl` a variadic template and (perfect) forward the
arguments for the used `assume` function.
2) Use a macros.
I have concerns though, whether these alternatives would deteriorate the
readability of the code.
Differential Revision: https://reviews.llvm.org/D125954
Depends on D124758. This is the very same thing we have done for
assumeDual, but this time we do it for assumeInclusiveRange. This patch
is basically a no-brainer copy of that previous patch.
Differential Revision:
https://reviews.llvm.org/D125892
Summary:
By evaluating both children states, now we are capable of discovering
infeasible parent states. In this patch, `assume` is implemented in the terms
of `assumeDuali`. This might be suboptimal (e.g. where there are adjacent
assume(true) and assume(false) calls, next patches addresses that). This patch
fixes a real CRASH.
Fixes https://github.com/llvm/llvm-project/issues/54272
Differential Revision:
https://reviews.llvm.org/D124758
In some cases a parent State is already infeasible, but we recognize
this only if an additonal constraint is added. This patch is the first
of a series to address this issue. In this patch `assumeDual` is changed
to clone the parent State but with an `Infeasible` flag set, and this
infeasible-parent is returned both for the true and false case. Then
when we add a new transition in the exploded graph and the destination
is marked as infeasible, the node will be a sink node.
Related bug:
https://github.com/llvm/llvm-project/issues/50883
Actually, this patch does not solve that bug in the solver, rather with
this patch we can handle the general parent-infeasible cases.
Next step would be to change the State API and require all checkers to
use the `assume*Dual` API and deprecate the simple `assume` calls.
Hopefully, the next patch will introduce `assumeInBoundDual` and will
solve the CRASH we have here:
https://github.com/llvm/llvm-project/issues/54272
Differential Revision: https://reviews.llvm.org/D124674
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Summary: SimpleConstraintManager is difficult to use, and makes assumptions about capabilities of the constraint manager. This patch refactors out those portions into a new RangedConstraintManager, and also fixes some issues with camel case, formatting, and confusing naming.
Reviewers: zaks.anna, dcoughlin
Subscribers: mgorny, xazax.hun, NoQ, rgov, cfe-commits
Differential Revision: https://reviews.llvm.org/D26061
llvm-svn: 296242
Summary: It breaks the build for the ASTMatchers
Subscribers: klimek, cfe-commits
Differential Revision: http://reviews.llvm.org/D13893
llvm-svn: 250827
Previously, every call to a ConstraintManager's isNull would do a full
assumeDual to test feasibility. Now, ConstraintManagers can override
checkNull if they have a cheaper way to do the same thing.
RangeConstraintManager can do this in less than half the work.
<rdar://problem/12608209>
llvm-svn: 167138
with at least one subtle bug in MacOSXKeyChainAPIChecker where the
calling the method was a substitute for assuming a symbolic value
was null (which is not the case).
We still keep ConstraintManager::getSymVal(), but we use that as
an optimization in SValBuilder and ProgramState::getSVal() to
constant-fold SVals. This is only if the ConstraintManager can
provide us with that information, which is no longer a requirement.
As part of this, introduce a default implementation of
ConstraintManager::getSymVal() which returns null.
For Checkers, introduce ConstraintManager::isNull(), which queries
the state to see if the symbolic value is constrained to be a null
value. It does this without assuming it has been implicitly constant
folded.
llvm-svn: 163428
Gabor Marton