By this change the `exploded-graph-rewriter` will display the class kind
of the expression of the environment entry. It makes easier to decide if
the given entry corresponds to the lvalue or to the rvalue of some
expression.
It turns out the rewriter already had support for visualizing it, but
probably was never actually used?
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D132109
It turns out that in certain cases `SymbolRegions` are wrapped by
`ElementRegions`; in others, it's not. This discrepancy can cause the
analyzer not to recognize if the two regions are actually referring to
the same entity, which then can lead to unreachable paths discovered.
Consider this example:
```lang=C++
struct Node { int* ptr; };
void with_structs(Node* n1) {
Node c = *n1; // copy
Node* n2 = &c;
clang_analyzer_dump(*n1); // lazy...
clang_analyzer_dump(*n2); // lazy...
clang_analyzer_dump(n1->ptr); // rval(n1->ptr): reg_$2<int * SymRegion{reg_$0<struct Node * n1>}.ptr>
clang_analyzer_dump(n2->ptr); // rval(n2->ptr): reg_$1<int * Element{SymRegion{reg_$0<struct Node * n1>},0 S64b,struct Node}.ptr>
clang_analyzer_eval(n1->ptr != n2->ptr); // UNKNOWN, bad!
(void)(*n1);
(void)(*n2);
}
```
The copy of `n1` will insert a new binding to the store; but for doing
that it actually must create a `TypedValueRegion` which it could pass to
the `LazyCompoundVal`. Since the memregion in question is a
`SymbolicRegion` - which is untyped, it needs to first wrap it into an
`ElementRegion` basically implementing this untyped -> typed conversion
for the sake of passing it to the `LazyCompoundVal`.
So, this is why we have `Element{SymRegion{.}, 0,struct Node}` for `n1`.
The problem appears if the analyzer evaluates a read from the expression
`n1->ptr`. The same logic won't apply for `SymbolRegionValues`, since
they accept raw `SubRegions`, hence the `SymbolicRegion` won't be
wrapped into an `ElementRegion` in that case.
Later when we arrive at the equality comparison, we cannot prove that
they are equal.
For more details check the corresponding thread on discourse:
https://discourse.llvm.org/t/are-symbolicregions-really-untyped/64406
---
In this patch, I'm eagerly wrapping each `SymbolicRegion` by an
`ElementRegion`; basically canonicalizing to this form.
It seems reasonable to do so since any object can be thought of as a single
array of that object; so this should not make much of a difference.
The tests also underpin this assumption, as only a few were broken by
this change; and actually fixed a FIXME along the way.
About the second example, which does the same copy operation - but on
the heap - it will be fixed by the next patch.
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D132142
This patch dumps every state trait in the egraph. Also
the empty state traits are no longer dumped, instead
they are treated as null by the egraph rewriter script,
which solves reverse compatibility issues.
Differential Revision: https://reviews.llvm.org/D131187
Introducing the support for evaluating the constructor
of every element in an array. The idea is to record the
index of the current array member being constructed and
create a loop during the analysis. We looping over the
same CXXConstructExpr as many times as many elements
the array has.
Differential Revision: https://reviews.llvm.org/D127973
In some rare cases the type of an SVal might be interesting.
This introspection function exposes this information in tests.
Reviewed By: martong
Differential Revision: https://reviews.llvm.org/D125532
This PR changes the `SymIntExpr` so the expression that uses a
negative value as `RHS`, for example: `x +/- (-N)`, is modeled as
`x -/+ N` instead.
This avoids producing a very large `RHS` when the symbol is cased to
an unsigned number, and as consequence makes the value more robust in
presence of casts.
Note that this change is not applied if `N` is the lowest negative
value for which negation would not be representable.
Reviewed By: steakhal
Patch By: tomasz-kaminski-sonarsource!
Differential Revision: https://reviews.llvm.org/D124658
It seems like multiple users are affected by a crash introduced by this
commit, thus I'm reverting it for the time being.
Read more about the found reproducers at Phabricator.
Differential Revision: https://reviews.llvm.org/D124658
This reverts commit f0d6cb4a5c.
This PR changes the `SymIntExpr` so the expression that uses a
negative value as `RHS`, for example: `x +/- (-N)`, is modeled as
`x -/+ N` instead.
This avoids producing a very large `RHS` when the symbol is cased to
an unsigned number, and as consequence makes the value more robust in
presence of casts.
Note that this change is not applied if `N` is the lowest negative
value for which negation would not be representable.
Reviewed By: steakhal
Patch By: tomasz-kaminski-sonarsource!
Differential Revision: https://reviews.llvm.org/D124658
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the ninth batch of tests being updated (there are a
significant number of other tests left to be updated).
None of these tests are really intended to test the file offset as much
as to test the structure. Making the regex allows this test to work
even if the file is checked out with CRLF line endings.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D119362
This reverts commit 6f3b775c3e.
Test fails flakily, see comments on https://reviews.llvm.org/D103967
Also revert follow-up "[Analyzer] Attempt to fix windows bots test
failure b/c of new-line"
This reverts commit fe0e861a4d.
This patch introduced additional PointerEscape callbacks after conservative
calls for output parameters. This should not really affect the current
checkers but the upcoming FuchsiaHandleChecker relies on this heavily.
Differential Revision: https://reviews.llvm.org/D71224
The '->' thing has always been confusing; the actual operation '->'
translates to a pointer dereference together with adding a FieldRegion,
but FieldRegion on its own doesn't imply an additional pointer
dereference.
llvm-svn: 375281
Summary:
This patch introduces `DynamicCastInfo` similar to `DynamicTypeInfo` which
is stored in `CastSets` which are storing the dynamic cast informations of
objects based on memory regions. It could be used to store and check the
casts and prevent infeasible paths.
Reviewed By: NoQ
Differential Revision: https://reviews.llvm.org/D66325
llvm-svn: 369605
- Correctly display macro expansion and spelling locations.
- Use the same procedure to display location context call site locations.
- Display statement IDs for program points.
llvm-svn: 365861
Include a unique pointer so that it was possible to figure out if it's
the same cluster in different program states. This allows comparing
dumps of different states against each other.
Differential Revision: https://reviews.llvm.org/D63362
llvm-svn: 363896
Location context ID is a property of the location context, not of an item
within it. It's useful to know the id even when there are no items
in the context, eg. for the purposes of figuring out how did contents
of the Environment for the same location context changed across states.
Differential Revision: https://reviews.llvm.org/D62754
llvm-svn: 363895
It makes it easier to discriminate between values of similar expressions
in different stack frames.
It also makes the separate backtrace section in ExplodedGraph dumps redundant.
Differential Revision: https://reviews.llvm.org/D42552
llvm-svn: 324660
- Fix the bug with transition handling in ExprInspectionChecker's
checkDeadSymbols implementation.
- Test this bug by adding a new function clang_analyzer_numTimesReached() to
catch number of passes through the code, which should be handy for testing
against unintended state splits.
- Add two more functions should help debugging issues quickly without running
the debugger or dumping exploded graphs - clang_analyzer_dump() which dump()s
an SVal argument to a warning message, and clang_analyzer_printState(), which
dump()s the current program state to stderr.
Differential Revision: https://reviews.llvm.org/D26835
llvm-svn: 288257
Balazs Benics