Patches the solver to assume that bitwise OR of an unsigned value with a
constant always produces a value larger-or-equal than the constant, and
bitwise AND with a constant always produces a value less-or-equal than
the constant.
This patch is especially useful in the context of using bitwise
arithmetic for error code encoding: the analyzer would be able to state
that the error code produced using a bitwise OR is non-zero.
Differential Revision: https://reviews.llvm.org/D39707
llvm-svn: 317820
The logical change is that the integers in SymIntExprs may not have the same type as the symbols they are paired with. This was already the case with taint-propagation expressions created by SValBuilder::makeSymExprValNN, but I think those integers may never have been used. SimpleSValBuilder should be able to handle mixed-integer-type SymIntExprs fine now, though, and the constraint managers were already being defensive (though not entirely correct). All existing tests pass.
The logic in evalBinOpNN has been simplified so that conversion is done as late as possible. As a result, most of the switch cases have been reduced to do the minimal amount of work, delegating to another case when they can by substituting ConcreteInts and (as before) reversing the left and right arguments when useful.
Comparisons require special handling in two places (building SymIntExprs and evaluating constant-constant operations) because we don't /know/ the best type for comparing the two values. I've approximated the rules in Sema [C99 6.3.1.8] but it'd be nice to refactor Sema's actual algorithm into ASTContext.
This is also groundwork for handling mixed-type constraints better than we do now.
llvm-svn: 156270
They cooperate in that NSErrorChecker listens for ImplicitNullDerefEvent events that
DereferenceChecker can dispatch.
ImplicitNullDerefEvent is when we dereferenced a location that may be null.
llvm-svn: 126659
CStringChecker
ChrootChecker
MallocChecker
PthreadLockChecker
StreamChecker
UnreachableCodeChecker
MallocChecker creates implicit dependencies between checkers and needs to be handled differently.
llvm-svn: 125598
implicit lvalue-to-rvalue casts that John McCall
recently introduced. This causes a whole bunch
of logic in the analyzer for handling lvalues
to vanish. It does, however, raise a few issues
in the analyzer w.r.t to modeling various constructs
(e.g., field accesses to compound literals).
The .c/.m analysis test cases that fail are
due to a missing lvalue-to-rvalue cast that
will get introduced into the AST. The .cpp
failures were more than I could investigate in
one go, and the patch was already getting huge.
I have XFAILED some of these tests, and they
should obviously be further investigated.
Some highlights of this patch include:
- CFG no longer requires an lvalue bit for
CFGElements
- StackFrameContext doesn't need an 'asLValue'
flag
- The "VisitLValue" path from GRExprEngine has
been eliminated.
Besides the test case failures (XFAILed), there
are surely other bugs that are fallout from
this change.
llvm-svn: 121960
- Renamed IdempotentOperationChecker::isConstant to isConstantOrPseudoConstant to better reflect the function
- Changed IdempotentOperationChecker::PreVisitBinaryOperator to only run 'CanVary' once on undefined assumptions
- Created new PsuedoConstantAnalysis class and added it to AnalysisContext
- Changed IdempotentOperationChecker to exploit the new analysis
- Updated tests with psuedo-constants
- Added check to IdempotentOperationChecker to see if a Decl is const qualified
llvm-svn: 111426
- Allowed reporting of dead macros
- Added path walking function to search for false positives in conditional statements
- Updated some affected tests
- Added some false positive test cases
llvm-svn: 109561
- Added checks for static local variables, self assigned parameters, and truncating/extending self assignments
- Removed command line option (now default with --analyze)
- Updated test cases to pass with idempotent operation warnings
llvm-svn: 108550
George Karpenkov