Commit Graph

5 Commits

Author SHA1 Message Date
Jordan Rose 9519ff59ec [analyzer] Handle zeroing constructors for fields of structs with empty bases.
RegionStore tries to protect against accidentally initializing the same
region twice, but it doesn't take subregions into account very well. If
the outer region being initialized is a struct with an empty base class,
the offset of the first field in the struct will be 0. When we initialize
the base class, we may invalidate the contents of the struct by providing
a default value of Unknown (or some new symbol). We then go to initialize
the member with a zeroing constructor, only to find that the region at
that offset in the struct already has a value. The best we can do here is
to invalidate that value and continue; neither the old default value nor
the new 0 is correct for the entire struct after the member constructor call.

The correct solution for this is to track region extents in the store.

<rdar://problem/14914316>

llvm-svn: 190530
2013-09-11 16:46:50 +00:00
Jordan Rose 05b2f98d89 [analyzer] Treat std::initializer_list as opaque rather than aborting.
Previously, the use of a std::initializer_list (actually, a
CXXStdInitializerListExpr) would cause the analyzer to give up on the rest
of the path. Now, it just uses an opaque symbolic value for the
initializer_list and continues on.

At some point in the future we can add proper support for initializer_list,
with access to the elements in the InitListExpr.

<rdar://problem/14340207>

llvm-svn: 186519
2013-07-17 17:16:33 +00:00
Jordan Rose b8e286548c [analyzer] Handle zeroing CXXConstructExprs.
Re-apply r184511, reverted in r184561, with the trivial default constructor
fast path removed -- it turned out not to be necessary here.

Certain expressions can cause a constructor invocation to zero-initialize
its object even if the constructor itself does no initialization. The
analyzer now handles that before evaluating the call to the constructor,
using the same "default binding" mechanism that calloc() uses, rather
than simply ignoring the zero-initialization flag.

<rdar://problem/14212563>

llvm-svn: 184815
2013-06-25 01:56:08 +00:00
Jordan Rose e83cb0922b Revert "[analyzer] Handle zeroing CXXConstructExprs."
Per review from Anna, this really should have been two commits, and besides
it's causing problems on our internal buildbot. Reverting until these have
been worked out.

This reverts r184511 / 98123284826bb4ce422775563ff1a01580ec5766.

llvm-svn: 184561
2013-06-21 16:30:32 +00:00
Jordan Rose 4ace1a74c0 [analyzer] Handle zeroing CXXConstructExprs.
Certain expressions can cause a constructor invocation to zero-initialize
its object even if the constructor itself does no initialization. The
analyzer now handles that before evaluating the call to the constructor,
using the same "default binding" mechanism that calloc() uses, rather
than simply ignoring the zero-initialization flag.

As a bonus, trivial default constructors are now no longer inlined; they
are instead processed explicitly by ExprEngine. This has a (positive)
effect on the generated path edges: they no longer stop at a default
constructor call unless there's a user-provided implementation.

<rdar://problem/14212563>

llvm-svn: 184511
2013-06-21 00:59:00 +00:00