Null dereferences are suppressed if the lvalue was constrained to 0 for the
first time inside a sub-function that was inlined during analysis, because
such constraint is a valid defensive check that does not, by itself,
indicate that null pointer case is anyhow special for the caller.
If further operations on the lvalue are performed, the symbolic lvalue is
collapsed to concrete null pointer, and we need to track where does the null
pointer come from.
Improve such tracking for lvalue operations involving operator &.
rdar://problem/27876009
Differential Revision: https://reviews.llvm.org/D31982
llvm-svn: 301224
The more detailed diagnostic will make identifying which object the
diagnostics refer to easier.
Differential Revision: https://reviews.llvm.org/D27740
llvm-svn: 289883
Returns when calling an inline function should not be merged in the ExplodedGraph unless they are same.
Differential Revision: https://reviews.llvm.org/D25326
llvm-svn: 283554
In the analyzer's path-sensitive reports, when a report goes through a branch
and the branch condition cannot be decided to be definitely true or false
(based on the previous execution path), an event piece is added that tells the
user that a new assumption is added upon the symbolic value of the branch
condition. For example, "Assuming 'a' is equal to 3".
The text of the assumption is hand-crafted in various manners depending on
the AST expression. If the AST expression is too complex and the text of
the assumption fails to be constructed, the event piece is omitted.
This causes loss of information and misunderstanding of the report.
Do not omit the event piece even if the expression is too complex;
add a piece with a generic text instead.
Differential Revision: https://reviews.llvm.org/D23300
llvm-svn: 283301
We should ignore paren casts when making sure that the semantic expression
in a PseudoObjectExpr for an ObjC getter is a message send.
This has no other intended functionality change.
Adding a test for this exposed an interesting issue in another test case
that only manifests under ARC. trackNullOrUndefValue() is not properly
suppressing for nil values that are the result of nil propagation from a nil
receiver when the nil is returned from a function. I've added a FIXME for that
missing suppression.
rdar://problem/27290568
llvm-svn: 279181
The analyzer does not model C++ temporary destructors completely and so
reports false alarms about leaks of memory allocated by the internals of
shared_ptr:
std::shared_ptr<int> p(new int(1));
p = nullptr; // 'Potential leak of memory pointed to by field __cntrl_'
This patch suppresses all diagnostics where the end of the path is inside
a method in std::shared_ptr.
It also reorganizes the tests for suppressions in the C++ standard library
to use a separate simulated header for library functions with bugs
that were deliberately inserted to test suppression. This will prevent
other tests from using these as models.
rdar://problem/23652766
llvm-svn: 274691
Teach trackNullOrUndefValue() how to properly look through PseudoObjectExprs
to find the underlying semantic method call for property getters. This fixes a
crash when looking through class property getters that I introduced in r265839.
rdar://problem/26796666
llvm-svn: 273340
Don't emit a path note marking the return site if the return statement does not
have a valid location. This fixes an assertion failure I introduced in r265839.
llvm-svn: 266031
Teach trackNullOrUndefValue() how to look through PseudoObjectExprs to find
the underlying method call for property getters. This makes over-suppression
of 'return nil' in getters consistent with the similar over-suppression for
method and function calls.
rdar://problem/24437252
llvm-svn: 265839
We already do this for case splits introduced as a result of defensive null
checks in functions and methods, so do the same for function-like macros.
rdar://problem/19640441
llvm-svn: 259222
visited decls.
Due to redeclarations, the function may have different declarations used
in CallExpr and in the definition. However, we need to use a unique
declaration for both store and lookup in VisitedCallees. This patch
fixes issues with analysis in topological order. A simple test is
included.
Patch by Alex Sidorin!
Differential Revision: http://reviews.llvm.org/D15410
llvm-svn: 257318
The analyzer reports a shift by a negative value in the constructor. The bug can
be easily triggered by calling std::random_shuffle on a vector
(<rdar://problem/19658126>).
(The shift by a negative value is reported because __w0_ gets constrained to
63 by the conditions along the path:__w0_ < _WDt && __w0_ >= _WDt-1,
where _WDt is 64. In normal execution, __w0_ is not 63, it is 1 and there is
no overflow. The path is infeasible, but the analyzer does not know about that.)
llvm-svn: 256886
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
Fixes https://llvm.org/bugs/show_bug.cgi?id=20744
struct A {
A() = default;
};
Previously the source range of the declaration of A ended at the ')'. It should
include the '= default' part as well. The same for '= delete'.
Note: this will break one of the clang-tidy fixers, which is going to be
addessed in a follow-up patch.
Differential Revision: http://reviews.llvm.org/D8465
llvm-svn: 233028
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
This silences false positives (leaks, use of uninitialized value) in simple
code that uses containers such as std::vector and std::list. The analyzer
cannot reason about the internal invariances of those data structures which
leads to false positives. Until we come up with a better solution to that
problem, let's just not inline the methods of the containers and allow objects
to escape whenever such methods are called.
This just extends an already existing flag "c++-container-inlining" and applies
the heuristic not only to constructors and destructors of the containers, but
to all of their methods.
We have a bunch of distinct user reports all related to this issue
(radar://16058651, radar://16580751, radar://16384286, radar://16795491
[PR19637]).
llvm-svn: 211832
When adding the implicit compound statement (required for Codegen?), the
end location was previously overridden by the start location, probably
based on the assumptions:
* The location of the compound statement should be the member's location
* The compound statement if present is the last element of a FunctionDecl
This patch changes the location of the compound statement to the
member's end location.
Code review: http://reviews.llvm.org/D4175
llvm-svn: 211344
This means always walking the whole call stack for the end path node, but
we'll assume that's always fairly tractable.
<rdar://problem/15952973>
llvm-svn: 200980
In preparation for making the Win32 triple imply MS ABI mode,
make all tests pass in this mode, or make them use the Itanium
mode explicitly.
Differential Revision: http://llvm-reviews.chandlerc.com/D2401
llvm-svn: 199130
This is similar to r194004: because we can't reason about the data structure
invariants of std::basic_string, the analyzer decides it's possible for an
allocator to be used to deallocate the string's inline storage. Just ignore
this by walking up the stack, skipping past methods in classes with
"allocator" in the name, and seeing if we reach std::basic_string that way.
PR17866
llvm-svn: 194764
...rather than trying to figure it out from the call site, and having
people complain that we guessed wrong and that a prototype-less call is
the same as a variadic call on their system. More importantly, fix a
crash when there's no decl at the call site (though we could have just
returned a default value).
<rdar://problem/15037033>
llvm-svn: 191599
We process autorelease counts when we exit functions, but if there's an
issue in a synthesized body the report will get dropped. Just skip the
processing for now and let it get handled when the caller gets around to
processing autoreleases.
(This is still suboptimal: objects autoreleased in the caller context
should never be warned about when exiting a callee context, synthesized
or not.)
Second half of <rdar://problem/14611722>
llvm-svn: 187625
Much of our diagnostic machinery is set up to assume that the report
end path location is valid. Moreover, the user may be quite confused
when something goes wrong in our BodyFarm-synthesized function bodies,
which may be simplified or modified from the real implementations.
Rather than try to make this all work somehow, just drop the report so
that we don't try to go on with an invalid source location.
Note that we still handle reports whose /paths/ go through invalid
locations, just not those that are reported in one.
We do have to be careful not to lose warnings because of this.
The impetus for this change was an autorelease being processed within
the synthesized body, and there may be other possible issues that are
worth reporting in some way. We'll take these as they come, however.
<rdar://problem/14611722>
llvm-svn: 187624
The motivation is to suppresses false use-after-free reports that occur when calling
std::list::pop_front() or std::list::pop_back() twice. The analyzer does not
reason about the internal invariants of the list implementation, so just do not report
any of warnings in std::list.
Fixes radar://14317928.
llvm-svn: 185609
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
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
...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
When generating path notes, implicit function bodies are shown at the call
site, so that, say, copying a POD type in C++ doesn't jump you to a header
file. This is especially important when the synthesized function itself
calls another function (or block), in which case we should try to jump the
user around as little as possible.
By checking whether a called function has a body in the AST, we can tell
if the analyzer synthesized the body, and if we should therefore collapse
the call down to the call site like a true implicitly-defined function.
<rdar://problem/13978414>
llvm-svn: 182677
found for a receiver, note where receiver class
is declaraed (this is most common when receiver is a forward
class). // rdar://3258331
llvm-svn: 181847
Artem Dergachev