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
Jordan Rose