This API is used by checkers (and other entities) in order to track where does
a value originate from, by jumping from an expression value of which is equal
to that value to the expression from which this value has "appeared". For
example, it may be an lvalue from which the rvalue was loaded, or a function
call from which the dereferenced pointer was returned.
The function now avoids incorrectly unwrapping implicit lvalue-to-rvalue casts,
which caused crashes and incorrect intermediate diagnostic pieces. It also no
longer relies on how the expression is written when guessing what it means.
Fixes pr34373 and pr34731.
rdar://problem/33594502
Differential Revision: https://reviews.llvm.org/D37023
llvm-svn: 314287
This patch adds hashes to the plist and html output to be able to identfy bugs
for suppressing false positives or diff results against a baseline. This hash
aims to be resilient for code evolution and is usable to identify bugs in two
different snapshots of the same software. One missing piece however is a
permanent unique identifier of the checker that produces the warning. Once that
issue is resolved, the hashes generated are going to change. Until that point
this feature is marked experimental, but it is suitable for early adoption.
Differential Revision: http://reviews.llvm.org/D10305
Original patch by: Bence Babati!
llvm-svn: 251011
to the plist output. This check_name field does not guaranteed to be the
same as the name of the checker in the future.
Reviewer: Anna Zaks
Differential Revision: http://reviews.llvm.org/D6841
llvm-svn: 228624
...but don't yet migrate over the existing plist tests. Some of these
would be trivial to migrate; others could use a bit of inspection first.
In any case, though, the new edge algorithm seems to have proven itself,
and we'd like more coverage (and more usage) of it going forwards.
llvm-svn: 183165
The 2 functions were computing the same location using different logic (each one had edge case bugs that the other
one did not). Refactor them to rely on the same logic.
The location of the warning reported in text/command line output format will now match that of the plist file.
There is one change in the plist output as well. When reporting an error on a BinaryOperator, we use the location of the
operator instead of the beginning of the BinaryOperator expression. This matches our output on command line and
looks better in most cases.
llvm-svn: 180165
Consider this case:
int *p = 0;
p = getPointerThatMayBeNull();
*p = 1;
If we inline 'getPointerThatMayBeNull', we might know that the value of 'p'
is NULL, and thus emit a null pointer dereference report. However, we
usually want to suppress such warnings as error paths, and we do so by using
FindLastStoreBRVisitor to see where the NULL came from. In this case, though,
because 'p' was NULL both before and after the assignment, the visitor
would decide that the "last store" was the initialization, not the
re-assignment.
This commit changes FindLastStoreBRVisitor to consider all PostStore nodes
that assign to this region. This still won't catches changes made directly
by checkers if they re-assign the same value, but it does handle the common
case in user-written code and will trigger ReturnVisitor's suppression
machinery as expected.
<rdar://problem/13299738>
llvm-svn: 176201
Fixes PR15358 and <rdar://problem/13295437>.
Along the way, shorten path diagnostics that say "Variable 'x'" to just
be "'x'". By the context, it is obvious that we have a variable,
and so this just consumes text space.
llvm-svn: 176115
path notes for cases where a value may be assumed to be null, etc.
Instead of having redundant diagnostics, do a pass over the generated
PathDiagnostic pieces and remove notes from TrackConstraintBRVisitor
that are already covered by ConditionBRVisitor, whose notes tend
to be better.
Fixes <rdar://problem/12252783>
llvm-svn: 166728
By analogy with C structs, this seems to be legal, if probably discouraged.
It's only if the ivar is read from or written to that there's a problem.
Running a program that gets the "address" of an instance variable does in
fact return the offset when the base "object" is nil.
This isn't a full revert because r164442 includes some diagnostic tweaks
as well; those have been kept.
This partially reverts r164442 / 08965091770c9b276c238bac2f716eaa4da2dca4.
llvm-svn: 164960
Like with struct fields, we want to catch cases like this early,
so that we can produce better diagnostics and path notes:
PointObj *p = nil;
int *px = &p->_x; // should warn here
*px = 1;
llvm-svn: 164442
Artem Dergachev