Commit Graph

12 Commits

Author SHA1 Message Date
Vince Bridgers 9ef7ac51af [analyzer] Fix crash in RangedConstraintManager.cpp
This change fixes a crash in RangedConstraintManager.cpp:assumeSym due to an
unhandled BO_Div case.

clang: <root>clang/lib/StaticAnalyzer/Core/RangedConstraintManager.cpp:51:
  virtual clang::ento::ProgramStateRef
  clang::ento::RangedConstraintManager::assumeSym(clang::ento::ProgramStateRef,
    clang::ento::SymbolRef, bool):
  Assertion `BinaryOperator::isComparisonOp(Op)' failed.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D122277
2022-03-23 08:26:40 -05:00
Gabor Marton a8297ed994 [Analyzer][solver] Handle adjustments in constraint assignor remainder
We can reuse the "adjustment" handling logic in the higher level
of the solver by calling `State->assume`.

Differential Revision: https://reviews.llvm.org/D112296
2021-10-27 17:14:34 +02:00
Gabor Marton ac3edc5af0 [analyzer][solver] Handle simplification to ConcreteInt
The solver's symbol simplification mechanism was not able to handle cases
when a symbol is simplified to a concrete integer. This patch adds the
capability.

E.g., in the attached lit test case, the original symbol is `c + 1` and
it has a `[0, 0]` range associated with it. Then, a new condition `c == 0`
is assumed, so a new range constraint `[0, 0]` comes in for `c` and
simplification kicks in. `c + 1` becomes `0 + 1`, but the associated
range is `[0, 0]`, so now we are able to realize the contradiction.

Differential Revision: https://reviews.llvm.org/D110913
2021-10-14 17:53:29 +02:00
Gabor Marton 0646e36254 [Analyzer][solver] Fix crashes during symbol simplification
Consider the code
```
  void f(int a0, int b0, int c)
  {
      int a1 = a0 - b0;
      int b1 = (unsigned)a1 + c;
      if (c == 0) {
          int d = 7L / b1;
      }
  }
```
At the point of divisiion by `b1` that is considered to be non-zero,
which results in a new constraint for `$a0 - $b0 + $c`. The type
of this sym is unsigned, however, the simplified sym is `$a0 -
$b0` and its type is signed. This is probably the result of the
inherent improper handling of casts. Anyway, Range assignment
for constraints use this type information. Therefore, we must
make sure that first we simplify the symbol and only then we
assign the range.

Differential Revision: https://reviews.llvm.org/D104844
2021-06-25 11:49:26 +02:00
Valeriy Savchenko 02b51e5316 [analyzer][solver] Redesign constraint ranges data structure
ImmutableSet doesn't seem like the perfect fit for the RangeSet
data structure.  It is good for saving memory in a persistent
setting, but not for the case when the population of the container
is tiny.  This commit replaces RangeSet implementation and
redesigns the most common operations to be more efficient.

Differential Revision: https://reviews.llvm.org/D86465
2021-03-22 13:52:35 +03:00
Valeriy Savchenko b13d9878b8 [analyzer][solver] Track symbol equivalence
Summary:
For the most cases, we try to reason about symbol either based on the
information we know about that symbol in particular or about its
composite parts.  This is faster and eliminates costly brute force
searches through existing constraints.

However, we do want to support some cases that are widespread enough
and involve reasoning about different existing constraints at once.
These include:
  * resoning about 'a - b' based on what we know about 'b - a'
  * reasoning about 'a <= b' based on what we know about 'a > b' or 'a < b'

This commit expands on that part by tracking symbols known to be equal
while still avoiding brute force searches.  It changes the way we track
constraints for individual symbols.  If we know for a fact that 'a == b'
then there is no need in tracking constraints for both 'a' and 'b' especially
if these constraints are different.  This additional relationship makes
dead/live logic for constraints harder as we want to maintain as much
information on the equivalence class as possible, but we still won't
carry the information that we don't need anymore.

Differential Revision: https://reviews.llvm.org/D82445
2020-07-22 13:02:39 +03:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Artem Dergachev 25dac79edf [analyzer] Be more plugin-friendly by moving static locals into .cpp files.
The GDMIndex functions return a pointer that's used as a key for looking up
data, but addresses of local statics defined in header files aren't the same
across shared library boundaries and the result is that analyzer plugins
can't access this data.

Event types are uniqued by using the addresses of a local static defined
in a header files, but it isn't the same across shared library boundaries
and plugins can't currently handle ImplicitNullDerefEvents.

Patches by Joe Ranieri!

Differential Revision: https://reviews.llvm.org/D52905
Differential Revision: https://reviews.llvm.org/D52906

llvm-svn: 344823
2018-10-20 00:29:24 +00:00
Mikhail R. Gadelha e254b0f8c7 [analyzer] Fix constraint being dropped when analyzing a program without taint tracking enabled
Summary:
This patch removes the constraint dropping when taint tracking is disabled.

It also voids the crash reported in D28953 by treating a SymSymExpr with non pointer symbols as an opaque expression.

Updated the regressions and verifying the big projects now; I'll update here when they're done.

Based on the discussion on the mailing list and the patches by @ddcc.

Reviewers: george.karpenkov, NoQ, ddcc, baloghadamsoftware

Reviewed By: george.karpenkov

Subscribers: delcypher, llvm-commits, rnkovacs, xazax.hun, szepet, a.sidorin, ddcc

Differential Revision: https://reviews.llvm.org/D48650

llvm-svn: 337167
2018-07-16 13:14:46 +00:00
Mikhail R. Gadelha c10f611522 Moved RangedConstraintManager header to the StaticAnalyser include dir
Summary:
Moved `RangedConstraintManager` header from  `lib/StaticAnalyzer/Core/` to `clang/StaticAnalyzer/Core/PathSensitive/`. No changes to the code.

Reviewers: NoQ, george.karpenkov, dcoughlin

Reviewed By: george.karpenkov

Subscribers: NoQ, george.karpenkov, dcoughlin, ddcc

Differential Revision: https://reviews.llvm.org/D47640

llvm-svn: 333862
2018-06-04 00:23:01 +00:00
Richard Smith c70f1d63f8 [c++20] P0515R3: Parsing support and basic AST construction for operator <=>.
Adding the new enumerator forced a bunch more changes into this patch than I
would have liked. The -Wtautological-compare warning was extended to properly
check the new comparison operator, clang-format needed updating because it uses
precedence levels as weights for determining where to break lines (and several
operators increased their precedence levels with this change), thread-safety
analysis needed changes to build its own IL properly for the new operator.

All "real" semantic checking for this operator has been deferred to a future
patch. For now, we use the relational comparison rules and arbitrarily give
the builtin form of the operator a return type of 'void'.

llvm-svn: 320707
2017-12-14 15:16:18 +00:00
Dominic Chen 9bc02cee8d [analyzer] Refactor and simplify SimpleConstraintManager
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
2017-02-25 04:51:31 +00:00