(Stmt*,LocationContext*) pairs to SVals instead of Stmt* to SVals.

This is needed to support basic IPA via inlining.  Without this, we cannot tell
if a Stmt* binding is part of the current analysis scope (StackFrameContext) or
part of a parent context.

This change introduces an uglification of the use of getSVal(), and thus takes
two steps forward and one step back.  There are also potential performance implications
of enlarging the Environment.  Both can be addressed going forward by refactoring the
APIs and optimizing the internal representation of Environment.  This patch
mainly introduces the functionality upon when we want to build upon (and clean up).

llvm-svn: 147688

as a result of a call.

Problem:
Global variables, which come in from system libraries should not be
invalidated by all calls. Also, non-system globals should not be
invalidated by system calls.

Solution:
The following solution to invalidation of globals seems flexible enough
for taint (does not invalidate stdin) and should not lead to too
many false positives. We split globals into 3 classes:

* immutable - values are preserved by calls (unless the specific
global is passed in as a parameter):
     A :  Most system globals and const scalars

* invalidated by functions defined in system headers:
     B: errno

* invalidated by all other functions (note, these functions may in
turn contain system calls):
     B: errno
     C: all other globals (which are not in A nor B)

llvm-svn: 147569

llvm-svn: 147566

llvm-svn: 147526

llvm-svn: 147505

Enhance UnixAPIChecker to also warn about zero-sized allocations to calloc() and realloc().  Patch by Cyril Roelandt!

llvm-svn: 147500

from C++ constructors or destructors.  Checker by Lei Zhang with a few tweaks by Ted Kremenek.

llvm-svn: 147494

llvm-svn: 147338

clients. No functionality change.

llvm-svn: 147318

llvm-svn: 147203

llvm-svn: 147139

type is a pointer to const. (radar://10595327)

The regions corresponding to the pointer and reference arguments to
a function get invalidated by the calls since a function call can
possibly modify the pointed to data. With this change, we are not going
to invalidate the data if the argument is a pointer to const. This
change makes the analyzer more optimistic in reporting errors.
(Support for C, C++ and Obj C)

llvm-svn: 147002

llvm-svn: 146993

llvm-svn: 146967

llvm-svn: 146959

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

llvm-svn: 146792

llvm-svn: 146748

llvm-svn: 146683

is deterministic.

Non-determinism was the reason for the test which caused the earlier
buildbot failures, so re-enable the test.

llvm-svn: 146628

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

llvm-svn: 146535

llvm-svn: 146533

Also, allow adding taint to a region (not only a symbolic value).

llvm-svn: 146532

[analyzer] CStringChecker should not rely on the analyzer generating UndefOrUnknown value when it cannot reason about the expression.

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

Forgot to commit the Header files. 
Rename generateUnknownVal -> makeGenericVal.

llvm-svn: 146337

Fix a bug in SimpleSValBuilder, where we should swap lhs and rhs when calling generateUnknownVal(), - the function which creates symbolic expressions when data is tainted. The issue is not visible when we only create the expressions for taint since all expressions are commutative from taint perspective.

Refactor SymExpr::symbol_iterator::expand() to use a switch instead of a chain of ifs.

llvm-svn: 146336

types are equivalent.

+ A taint test which tests bitwise operations and which was
triggering an assertion due to presence of the integer to integer cast.

llvm-svn: 146240

+ random comments

llvm-svn: 146199

llvm-svn: 146146

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

llvm-svn: 146056

SVal can be not only a symbol, but a MemRegion. Add support for such
cases.

llvm-svn: 146006

for a foldable constant rather than an IR-level constant. This is still far too
liberal, but is a step in the right direction.

llvm-svn: 145990

llvm-svn: 145987

for finding dependent symbols for taint.

llvm-svn: 145986

 - Created a new SymExpr type - SymbolCast.
 - SymbolCast is created when we don't know how to simplify a NonLoc to
NonLoc casts.
 - A bit of code refactoring: introduced dispatchCast to have better
code reuse, remove a goto.
 - Updated the test case to showcase the new taint flow.

llvm-svn: 145985

llvm-svn: 145984

(Previously, Clang used it's implementation of dominators.)

The patch is contributed by Guoping Long!

llvm-svn: 145858

llvm-svn: 145857