Commit Graph

27 Commits

Author SHA1 Message Date
Gabor Horvath efec16307c [analyzer] Bug identification
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
2015-10-22 11:53:04 +00:00
Jordan Rose 3da3f8e045 [analyzer] Disable all retain count diagnostics on values that come from ivars.
This is imitating a pre-r228174 state where ivars are not considered tracked by
default, but with the addition that even ivars /with/ retain count information
(e.g. "[_ivar retain]; [ivar _release];") are not being tracked as well. This is
to ensure that we don't regress on values accessed through both properties and
ivars, which is what r228174 was trying to fix.

The issue occurs in code like this:

  [_contentView retain];
  [_contentView removeFromSuperview];
  [self addSubview:_contentView]; // invalidates 'self'
  [_contentView release];

In this case, the call to -addSubview: may change the value of self->_contentView,
and so the analyzer can't be sure that we didn't leak the original _contentView.
This is a correct conservative view of the world, but not a useful one. Until we
have a heuristic that allows us to not consider this a leak, not emitting a
diagnostic is our best bet.

This commit disables all of the ivar-related retain count tests, but does not
remove them to ensure that we don't crash trying to evaluate either valid or
erroneous code. The next commit will add a new test for the example above so
that this commit (and the previous one) can be reverted wholesale when a better
solution is implemented.

Rest of rdar://problem/20335433

llvm-svn: 233592
2015-03-30 20:18:00 +00:00
Jordan Rose 218772f87e [analyzer] Don't special-case ivars backing +0 properties.
Give up this checking in order to continue tracking that these values came from
direct ivar access, which will be important in the next commit.

Part of rdar://problem/20335433

llvm-svn: 233591
2015-03-30 20:17:47 +00:00
Gabor Horvath c18a11397c [Static Analyzer] The name of the checker that reports a bug is added
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
2015-02-09 22:52:26 +00:00
Jordan Rose cb5386cbfc [analyzer] RetainCountChecker: be forgiving when ivars are accessed directly.
A refinement of r204730, itself a refinement of r198953, to better handle
cases where an object is accessed both through a property getter and
through direct ivar access. An object accessed through a property should
always be treated as +0, i.e. not owned by the caller. However, an object
accessed through an ivar may be at +0 or at +1, depending on whether the
ivar is a strong reference. Outside of ARC, we don't always have that
information.

The previous attempt would clear out the +0 provided by a getter, but only
if that +0 hadn't already participated in other retain counting operations.
(That is, "self.foo" is okay, but "[[self.foo retain] autorelease]" is
problematic.) This turned out to not be good enough when our synthesized
getters get involved.

This commit drops the notion of "overridable" reference counting and instead
just tracks whether a value ever came from a (strong) ivar. If it has, we
allow one more release than we otherwise would. This has the added benefit
of being able to catch /some/ overreleases of instance variables, though
it's not likely to come up in practice.

We do still get some false negatives because we currently throw away
refcount state upon assigning a value into an ivar. We should probably
improve on that in the future, especially once we synthesize setters as
well as getters.

rdar://problem/18075108

llvm-svn: 228174
2015-02-04 19:24:52 +00:00
Jordan Rose 7741132f47 [analyzer] RetainCountChecker: add support for CFAutorelease.
<rdar://problems/13710586&13710643>

llvm-svn: 192113
2013-10-07 17:16:52 +00:00
Jordan Rose 367843a04c [analyzer] Merge TextPathDiagnostics and ClangDiagPathDiagConsumer.
This once again restores notes to following their associated warnings
in -analyzer-output=text mode. (This is still only intended for use as a
debugging aid.)

One twist is that the warning locations in "regular" analysis output modes
(plist, multi-file-plist, html, and plist-html) are reported at a different
location on the command line than in the output file, since the command
line has no path context. This commit makes -analyzer-output=text behave
like a normal output format, which means that the *command line output
will be different* in -analyzer-text mode. Again, since -analyzer-text is
a debugging aid and lo-fi stand-in for a regular output mode, this change
makes sense.

Along the way, remove a few pieces of stale code related to the path
diagnostic consumers.

llvm-svn: 188514
2013-08-16 01:06:30 +00:00
Jordan Rose 5e2b3a30a0 [analyzer] Enable the new edge algorithm by default.
...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
2013-06-03 23:00:19 +00:00
Anna Zaks 404028798f [analyzer] Set the allocation site to be the uniqueing location for retain count checker leaks.
The uniqueing location is the location which is part of the hash used to determine if two reports are
the same. This is used by the CmpRuns.py script to compare two analyzer runs and determine which
warnings are new.

llvm-svn: 180166
2013-04-23 23:57:50 +00:00
Jordan Rose 7467f06533 [analyzer] RetainCountChecker: Clean up path notes for autorelease.
No functionality change.

<rdar://problem/13710586>

llvm-svn: 180075
2013-04-23 01:42:25 +00:00
Jordan Rose 526d93c55d [analyzer] Show "Returning from ..." note at caller's depth, not callee's.
Before:
  1. Calling 'foo'
    2. Doing something interesting
    3. Returning from 'foo'
  4. Some kind of error here

After:
  1. Calling 'foo'
    2. Doing something interesting
  3. Returning from 'foo'
  4. Some kind of error here

The location of the note is already in the caller, not the callee, so this
just brings the "depth" attribute in line with that.

This only affects plist diagnostic consumers (i.e. Xcode). It's necessary
for Xcode to associate the control flow arrows with the right stack frame.

<rdar://problem/13634363>

llvm-svn: 179351
2013-04-12 00:44:17 +00:00
Jordan Rose ce781ae6ae [analyzer] Don't emit extra context arrow after returning from an inlined call.
In this code

  int getZero() {
    return 0;
  }

  void test() {
    int problem = 1 / getZero(); // expected-warning {{Division by zero}}
  }

we generate these arrows:

    +-----------------+
    |                 v
    int problem = 1 / getZero();
                  ^   |
                  +---+

where the top one represents the control flow up to the first call, and the
bottom one represents the flow to the division.* It turns out, however, that
we were generating the top arrow twice, as if attempting to "set up context"
after we had already returned from the call. This resulted in poor
highlighting in Xcode.

* Arguably the best location for the division is the '/', but that's a
  different problem.

<rdar://problem/13326040>

llvm-svn: 179350
2013-04-12 00:44:01 +00:00
Anna Zaks e51362e7f7 [analyzer] When reporting a leak in RetainCount checker due to an early exit from init, step into init.
The heuristic here (proposed by Jordan) is that, usually, if a leak is due to an early exit from init, the allocation site will be
a call to alloc. Note that in other cases init resets self to [super init], which becomes the allocation site of the object.

llvm-svn: 179221
2013-04-10 21:42:06 +00:00
Anna Zaks 58b961d176 [analyzer] Plist: change the type of issue_hash from int to string.
This gives more flexibility to what could be stored as issue_hash.

llvm-svn: 171824
2013-01-08 00:25:22 +00:00
Jordan Rose ff03c1d26d [analyzer] Simplify RetainCountChecker's handling of dead symbols.
Previously we made three passes over the set of dead symbols, and removed
them from the state /twice/. Now we combine the autorelease pass and the
symbol death pass, and only have to remove the bindings for the symbols
that leaked.

llvm-svn: 169527
2012-12-06 18:58:18 +00:00
Ted Kremenek a5958869f6 TrackConstraintBRVisitor and ConditionBRVisitor can emit similar
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
2012-10-25 22:07:10 +00:00
Jordan Rose a3e3343e51 [analyzer] Add plist output checks for all four "path notes" tests.
No functionality change, but from now on, any new path notes should be
tested both with plain-text output (for ease of human auditing) and with
plist output (to ensure control flow and events are being correctly
represented in Xcode).

llvm-svn: 161351
2012-08-06 21:28:14 +00:00
Jordan Rose 627b046c88 [analyzer] Combine all ObjC message CallEvents into ObjCMethodCall.
As pointed out by Anna, we only differentiate between explicit message sends

This also adds support for ObjCSubscriptExprs, which are basically the same
as properties in many ways. We were already checking these, but not emitting
nice messages for them.

This depends on the llvm::PointerIntPair change in r160456.

llvm-svn: 160461
2012-07-18 21:59:51 +00:00
Jordy Rose 6393f82b5b [analyzer] RetainCountChecker: track ObjC boxed expression objects.
llvm-svn: 156699
2012-05-12 05:10:43 +00:00
Jordy Rose 78373e505d [analyzer] Don't claim an object was returned with +1 retain count before counting autoreleases. Fixes PR10376.
(Also, 80-column violations.)

llvm-svn: 152976
2012-03-17 05:49:15 +00:00
Ted Kremenek 5586354d7d Fix typos in analyzer diagnostics pointed out by Matt Beaumont-Gay and Robert Purves.
llvm-svn: 147139
2011-12-22 06:35:52 +00:00
Richard Trieu 553b2b2e5d Modify how the -verify flag works. Currently, the verification string and
diagnostic message are compared.  If either is a substring of the other, then
no error is given.  This gives rise to an unexpected case:

  // expect-error{{candidate function has different number of parameters}}

will match the following error messages from Clang:

  candidate function has different number of parameters (expected 1 but has 2)
  candidate function has different number of parameters

It will also match these other error messages:

  candidate function
  function has different number of parameters
  number of parameters

This patch will change so that the verification string must be a substring of
the diagnostic message before accepting.  Also, all the failing tests from this
change have been corrected.  Some stats from this cleanup:

87 - removed extra spaces around verification strings
70 - wording updates to diagnostics
40 - extra leading or trailing characters (typos, unmatched parens or quotes)
35 - diagnostic level was included (error:, warning:, or note:)
18 - flag name put in the warning (-Wprotocol)

llvm-svn: 146619
2011-12-15 00:38:15 +00:00
Ted Kremenek 8e7fbcc3e4 [static analyzer] Tweak RetainCountChecker's diagnostics to correctly indicate if a message was due to a property access. This can
potentially be refactored for other clients, and this is a regression from the refactoring of property acceses.

llvm-svn: 144571
2011-11-14 21:59:21 +00:00
John McCall fe96e0b6be Change the AST representation of operations on Objective-C
property references to use a new PseudoObjectExpr
expression which pairs a syntactic form of the expression
with a set of semantic expressions implementing it.
This should significantly reduce the complexity required
elsewhere in the compiler to deal with these kinds of
expressions (e.g. IR generation's special l-value kind,
the static analyzer's Message abstraction), at the lower
cost of specifically dealing with the odd AST structure
of these expressions.  It should also greatly simplify
efforts to implement similar language features in the
future, most notably Managed C++'s properties and indexed
properties.

Most of the effort here is in dealing with the various
clients of the AST.  I've gone ahead and simplified the
ObjC rewriter's use of properties;  other clients, like
IR-gen and the static analyzer, have all the old
complexity *and* all the new complexity, at least
temporarily.  Many thanks to Ted for writing and advising
on the necessary changes to the static analyzer.

I've xfailed a small diagnostics regression in the static
analyzer at Ted's request.

llvm-svn: 143867
2011-11-06 09:01:30 +00:00
Jordy Rose c49ec53e29 [analyzer] Move the knowledge of whether or not GC is enabled for the current analysis from CFRefCount to ExprEngine.
Remove TransferFuncs from ExprEngine and AnalysisConsumer.

Demote RetainReleaseChecker to a regular checker, and give it the name osx.cocoa.RetainCount (class name change coming shortly). Update tests accordingly.

llvm-svn: 138998
2011-09-02 05:55:19 +00:00
Ted Kremenek 73665188fc Really remove FlatStoreManager and BasicStoreManager, this time from the driver. Also remove associated tests. Sorry for the messy commits; this is the result of a botched Git merge.
llvm-svn: 136422
2011-07-28 23:08:16 +00:00
Jordy Rose 43426f8fcb Add tests for CFRefReport's path notes, and fix a few typos and non-standard terminology ('+0 retain counts') caught by the tests.
llvm-svn: 135310
2011-07-15 22:17:54 +00:00