Check if the input parameters are tainted (or point to tainted data) on
a checkPreStmt<CallExpr>. If the output should be tainted, record it in
the state. On post visit (checkPostStmt<CallExpr>), use the state to
make decisions (in addition to the existing logic). Use this logic for
atoi and fscanf.
llvm-svn: 146793
Some of the test cases do not currently work because the analyzer core
does not seem to call checkers for pre/post DeclRefExpr visits.
(Opened radar://10573500. To be fixed later on.)
llvm-svn: 146536
We are now often generating expressions even if the solver is not known to be able to simplify it. This is another cleanup of the existing code, where the rest of the analyzer and checkers should not base their logic on knowing ahead of the time what the solver can reason about.
In this case, CStringChecker is performing a check for overflow of 'left+right' operation. The overflow can be checked with either 'maxVal-left' or 'maxVal-right'. Previously, the decision was based on whether the expresion evaluated to undef or not. With this patch, we check if one of the arguments is a constant, in which case we know that 'maxVal-const' is easily simplified. (Another option is to use canReasonAbout() method of the solver here, however, it's currently is protected.)
This patch also contains 2 small bug fixes:
- swap the order of operators inside SValBuilder::makeGenericVal.
- handle a case when AddeVal is unknown in GenericTaintChecker::getPointedToSymbol.
llvm-svn: 146343
between the casted type of the return value of a malloc/calloc/realloc
call and the operand of any sizeof expressions contained within
its argument(s).
llvm-svn: 146144
We trigger an error if free is called after a possibly failed allocation. Do not trigger the error if we know that the buffer is not null.
llvm-svn: 145584
We are getting name of the called function or it's declaration in a few checkers. Refactor them to use the helper function in the CheckerContext.
llvm-svn: 145576
explicit template specializations (which represent actual functions somebody wrote).
Along the way, refactor some other code which similarly cares about whether or
not they are looking at a template instantiation.
llvm-svn: 145547
Change the ArrayBoundCheckerV2 to be more aggressive in reporting buffer overflows
when the offset is tainted. Previously, we did not report bugs when the state was
underconstrained (not enough information about the bound to determine if there is
an overflow) to avoid false positives. However, if we know that the buffer
offset is tainted - comes in from the user space and can be anything, we should
report it as a bug.
+ The very first example of us catching a taint related bug.
This is the only example we can currently handle. More to come...
llvm-svn: 144826
Analysis by Ted:
"
if (stateZero && !stateNotZero) {
is checking to see if:
(A) "it is possible for the value to be zero" (stateZero)
AND
(B) "it is not possible for the value to be non-zero" (!stateNotZero)
That said, the only way for both B to be true AND A to be false is if the path is completely infeasible by the time we reach the divide-by-zero check. For the most part (all cases?), such cases should automatically get pruned out at branches (i.e., an infeasible path gets dropped), which is the case in our tests. So the question is whether or not such an infeasible path might not get dropped earlier? I can't envision any right now.
Indeed, the rest of the checker assumes that if the bug condition didn't fire then 'stateNotZero' is non-NULL:
C.addTransition(stateNotZero);
"
llvm-svn: 144114
A step toward making sure that diagnostics report should only
be generated though the CheckerContext and not though BugReporter
or ExprEngine directly.
llvm-svn: 142947
Remove dead members/parameters: ProgramState, respondsToCallback, autoTransition.
Remove addTransition method since it's the same as generateNode. Maybe we should
rename generateNode to genTransition (since a transition is always automatically
generated)?
llvm-svn: 142946
Get rid of the EndOfPathBuilder completely.
Use the generic NodeBuilder to generate nodes.
Enqueue the end of path frontier explicitly.
llvm-svn: 142943
NodeBuilder should not assume it's dealing with a single predecessor. Remove predecessor getters. Modify the BranchNodeBuilder to not be responsible for doing auto-transitions (which depend on a predecessor).
llvm-svn: 142453
Take advantage of the new builders for branch processing. As part of this change pass generic NodeBuilder (instead of BranchNodeBuilder) to the BranchCondition callback and remove the unused methods form BranchBuilder.
llvm-svn: 142448
Currently we have a bunch of different node builders which provide some common
functionality but are difficult to refactor. Each builder generates nodes of
different kinds and calculates the frontier nodes, which should be propagated
to the next step (after the builder dies).
Introduce a new NodeBuilder which provides very basic node generation facilities
but takes care of the second problem. The idea is that all the other builders
will eventually use it. Use this builder in CheckerContext instead of
StmtNodeBuilder (the way the frontier is propagated to the StmtBuilder
is a hack and will be removed later on).
llvm-svn: 142443
- Remodel Expr::EvaluateAsInt to behave like the other EvaluateAs* functions,
and add Expr::EvaluateKnownConstInt to capture the current fold-or-assert
behaviour.
- Factor out evaluation of bitfield bit widths.
- Fix a few places which would evaluate an expression twice: once to determine
whether it is a constant expression, then again to get the value.
llvm-svn: 141561
- Remove unused FindUndefExpr::ProgramStateManager.
- The Condition parameter of the callback is the terminator of the block, no need to retrieve it again.
llvm-svn: 141027
Instead of always storing all source locations for the selector identifiers
we check whether all the identifiers are in a "standard" position; "standard" position is
-Immediately before the arguments: -(id)first:(int)x second:(int)y;
-With a space between the arguments: -(id)first: (int)x second: (int)y;
-For nullary selectors, immediately before ';': -(void)release;
In such cases we infer the locations instead of storing them.
llvm-svn: 140989
to take a FunctionDecl* instead of an llvm::StringRef. Eventually
we might push more logic in there, like using slightly different
conventions for C++ methods.
Also, fix a bug where 'copy' and 'create' were being caught in
non-camel-cased strings. We want copyFoo and CopyFoo and XCopy
but not Xcopy or xcopy.
llvm-svn: 140911
- Fix a fixme and move the logic of creating a PathDiagnosticLocation corresponding to a ProgramPoint into a PathDiagnosticLocation constructor.
- Rename PathDiagnosticLocation::create to differentiate from the added constructor.
llvm-svn: 139825
- Modify all PathDiagnosticLocation constructors that take Stmt to also requre LocationContext.
- Add a constructor which should be used in case there is no valid statement/location (it will grab the location of the enclosing function).
llvm-svn: 139763
language options. Use that .def file to declare the LangOptions class
and initialize all of its members, eliminating a source of annoying
initialization bugs.
AST serialization changes are next up.
llvm-svn: 139605
Remove TransferFuncs from ExprEngine and AnalysisConsumer.
Demote RetainReleaseChecker to a regular checker, and give it the name osx.cocoa.RetainCount (class name change coming shortly). Update tests accordingly.
llvm-svn: 138998
builtin types (When requested). This is another step toward making
ASTUnit build the ASTContext as needed when loading an AST file,
rather than doing so after the fact. No actual functionality change (yet).
llvm-svn: 138985
Also, allow CallOrObjCMessage to wrap a CXXConstructExpr as well.
Finally, this allows us to remove the clunky whitelisting system from CFRefCount/RetainReleaseChecker. Slight regression due to CXXNewExprs not yet being handled in post-statement callbacks (PR forthcoming).
llvm-svn: 138716
Also convert stack-addr-ps.cpp to use the analyzer instead of just Sema, now
that it doesn't crash, and extract the stack-block test into another file since
it errors, and that prevents the analyzer from running.
llvm-svn: 138613
1) Create a header file to expose the predefined visitors. And move the parent(BugReporterVisitor) there as well.
2) Remove the registerXXXVisitor functions - the Visitor constructors/getters can be used now to create the object. One exception is registerVarDeclsLastStore(), which registers more then one visitor, so make it static member of FindLastStoreBRVisitor.
3) Modify all the checkers to use the new API.
llvm-svn: 138126
Having a notion of an actual ProgramPointTag will aid in introspection of the analyzer's behavior.
For example, the GraphViz output of the analyzer will pretty-print the tags in a useful manner.
llvm-svn: 137529
Report errors earlier: on checkDeadSymbols() and clear the state after the symbol we are tracking goes out of scope.
Also, perform lazy error checking. Instead of forcing the paths to be split depending one the return value of the allocator, make the return symbol depend on the allocated data symbol, which prolongs its life span to the time when the allocated data symbol becomes dead.
llvm-svn: 137523
The motivation of this large change is to drastically simplify the logic in ExprEngine going forward.
Some fallout is that the output of some BugReporterVisitors is not as accurate as before; those will
need to be fixed over time. There is also some possible performance regression as RemoveDeadBindings
will be called frequently; this can also be improved over time.
llvm-svn: 136419
MaterializeTemporaryExpr captures a reference binding to a temporary
value, making explicit that the temporary value (a prvalue) needs to
be materialized into memory so that its address can be used. The
intended AST invariant here is that a reference will always bind to a
glvalue, and MaterializeTemporaryExpr will be used to convert prvalues
into glvalues for that binding to happen. For example, given
const int& r = 1.0;
The initializer of "r" will be a MaterializeTemporaryExpr whose
subexpression is an implicit conversion from the double literal "1.0"
to an integer value.
IR generation benefits most from this new node, since it was
previously guessing (badly) when to materialize temporaries for the
purposes of reference binding. There are likely more refactoring and
cleanups we could perform there, but the introduction of
MaterializeTemporaryExpr fixes PR9565, a case where IR generation
would effectively bind a const reference directly to a bitfield in a
struct. Addresses <rdar://problem/9552231>.
llvm-svn: 133521
Language-design credit goes to a lot of people, but I particularly want
to single out Blaine Garst and Patrick Beard for their contributions.
Compiler implementation credit goes to Argyrios, Doug, Fariborz, and myself,
in no particular order.
llvm-svn: 133103
Ted Kremenek