Add a defensive check against an invalid destructor in the CFG.
Unions with fields with destructors have their own destructor implicitly
deleted. Due to a bug in the CFG we're still trying to evaluate them
at the end of the object's lifetime and crash because we are unable
to find the destructor's declaration.
rdar://problem/47362608
Differential Revision: https://reviews.llvm.org/D56899
llvm-svn: 351610
It's an old bug that consists in stale references to symbols remaining in the
GDM if they disappear from other program state sections as a result of any
operation that isn't the actual dead symbol collection. The most common example
here is:
FILE *fp = fopen("myfile.txt", "w");
fp = 0; // leak of file descriptor
In this example the leak were not detected previously because the symbol
disappears from the public part of the program state due to evaluating
the assignment. For that reason the checker never receives a notification
that the symbol is dead, and never reports a leak.
This patch not only causes leak false negatives, but also a number of other
problems, including false positives on some checkers.
What's worse, even though the program state contains a finite number of symbols,
the set of symbols that dies is potentially infinite. This means that is
impossible to compute the set of all dead symbols to pass off to the checkers
for cleaning up their part of the GDM.
No longer compute the dead set at all. Disallow iterating over dead symbols.
Disallow querying if any symbols are dead. Remove the API for marking symbols
as dead, as it is no longer necessary. Update checkers accordingly.
Differential Revision: https://reviews.llvm.org/D18860
llvm-svn: 347953
We weren't invalidating our unions correctly. The previous behavior in
invalidateRegionsWorker::VisitCluster() was to direct-bind an UnknownVal
to the union (at offset 0).
For that reason we were never actually loading default bindings from our unions,
because there never was any default binding to load, and the value
that is presumed when there's no default binding to load
is usually completely incorrect (eg. UndefinedVal for stack unions).
The new behavior is to default-bind a conjured symbol (of irrelevant type)
to the union that's being invalidated, similarly to what we do for structures
and classes. Then it becomes safe to load the value properly.
Differential Revision: https://reviews.llvm.org/D45241
llvm-svn: 331563
This ensures that variables accessible through a union are invalidated when
the union value is passed to a function. We still don't fully handle union
values, but this should at least quiet some false positives.
PR16596
llvm-svn: 193265
This time, actually uncomment the code that's supposed to fix the problem.
This reverts r165671 / 8ceb837585ed973dc36fba8dfc57ef60fc8f2735.
llvm-svn: 165676
Author: Jordan Rose <jordan_rose@apple.com>
Date: Wed Oct 10 21:31:21 2012 +0000
[analyzer] Treat fields of unions as having symbolic offsets.
This allows only one field to be active at a time in RegionStore.
This isn't quite the correct behavior for unions, but it at least
would handle the case of "value goes in, value comes out" from the
same field.
RegionStore currently has a number of places where any access to a union
results in UnknownVal being returned. However, it is clearly missing
some cases, or the original issue wouldn't have occurred. It is probably
now safe to remove those changes, but that's a potentially destabilizing
change that should wait for more thorough testing.
Fixes PR14054.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165660 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit cf9030e480f77ab349672f00ad302e216c26c92c.
llvm-svn: 165671
This allows only one field to be active at a time in RegionStore.
This isn't quite the correct behavior for unions, but it at least
would handle the case of "value goes in, value comes out" from the
same field.
RegionStore currently has a number of places where any access to a union
results in UnknownVal being returned. However, it is clearly missing
some cases, or the original issue wouldn't have occurred. It is probably
now safe to remove those changes, but that's a potentially destabilizing
change that should wait for more thorough testing.
Fixes PR14054.
llvm-svn: 165660
Artem Dergachev