Commit Graph

35 Commits

Author SHA1 Message Date
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
Jordan Rose 5250b873bb CFG: In a DeclStmt, skip anything that's not a VarDecl.
Neither the compiler nor the analyzer are doing anything with non-VarDecl
decls in the CFG, and having them there creates extra nodes in the
analyzer's path diagnostics. Simplify the CFG (and the path edges) by
simply leaving them out. We can always add interesting decls back in when
they become relevant.

Note that this only affects decls declared in a DeclStmt, and then only
those that appear within a function body.

llvm-svn: 183157
2013-06-03 22:59:41 +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
Anna Zaks 4e16b29c13 [analyzer] Refactor BugReport::getLocation and PathDiagnosticLocation::createEndOfPath for greater code reuse
The 2 functions were computing the same location using different logic (each one had edge case bugs that the other
one did not). Refactor them to rely on the same logic.

The location of the warning reported in text/command line output format will now match that of the plist file.

There is one change in the plist output as well. When reporting an error on a BinaryOperator, we use the location of the
operator instead of the beginning of the BinaryOperator expression. This matches our output on command line and
looks better in most cases.

llvm-svn: 180165
2013-04-23 23:57:43 +00:00
Ted Kremenek 37c777ecc0 [analyzer] Use 'MemRegion::printPretty()' instead of assuming the region is a VarRegion.
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
2013-02-26 19:44:38 +00:00
Ted Kremenek 9625048278 [analyzer] tracking stores/constraints now works for ObjC ivars or struct fields.
This required more changes than I originally expected:

- ObjCIvarRegion implements "canPrintPretty" et al
- DereferenceChecker indicates the null pointer source is an ivar
- bugreporter::trackNullOrUndefValue() uses an alternate algorithm
  to compute the location region to track by scouring the ExplodedGraph.
  This allows us to get the actual MemRegion for variables, ivars,
  fields, etc.  We only hand construct a VarRegion for C++ references.
- ExplodedGraph no longer drops nodes for expressions that are marked
  'lvalue'.  This is to facilitate the logic in the previous bullet.
  This may lead to a slight increase in size in the ExplodedGraph,
  which I have not measured, but it is likely not to be a big deal.

I have validated each of the changed plist output.

Fixes <rdar://problem/12114812>

llvm-svn: 175988
2013-02-24 07:21:01 +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 e37ab50a6e [analyzer] Report leaks at the closing brace of a function body.
This fixes a few cases where we'd emit path notes like this:

  +---+
 1|   v
  p = malloc(len);
  ^   |2
  +---+

In general this should make path notes more consistent and more correct,
especially in cases where the leak happens on the false branch of an if
that jumps directly to the end of the function. There are a couple places
where the leak is reported farther away from the cause; these are usually
cases where there are several levels of nested braces before the end of
the function. This still matches our current behavior for when there /is/
a statement after all the braces, though.

llvm-svn: 168070
2012-11-15 19:11:43 +00:00
Jordan Rose b5b0fc196e [analyzer] Mark symbol values as dead in the environment.
This allows us to properly remove dead bindings at the end of the top-level
stack frame, using the ReturnStmt, if there is one, to keep the return value
live. This in turn removes the need for a check::EndPath callback in leak
checkers.

This does cause some changes in the path notes for leak checkers. Previously,
a leak would be reported at the location of the closing brace in a function.
Now, it gets reported at the last statement. This matches the way leaks are
currently reported for inlined functions, but is less than ideal for both.

llvm-svn: 168066
2012-11-15 19:11:27 +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 4ac7cba404 [analyzer] Track a null value back through FindLastStoreBRVisitor.
Also, tidy up the other tracking visitors so that they mark the right
things as interesting and don't do extra work.

llvm-svn: 164448
2012-09-22 01:25:00 +00:00
Ted Kremenek e7ec4ef48d Fix bug in BugReporter::RemoveUneededCalls() where "prunable"
PathDiagnosticEventPieces were *always* pruned.  Instead, they
are suppose to only be pruned if the entire call gets pruned.

llvm-svn: 163460
2012-09-08 07:18:18 +00:00
Ted Kremenek b0d1c70258 Attempt (again) to stabilize the order of the emission of diagnostics
of the analyzer by using the FullProfile() of a PathDiagnostic
for ordering them.

llvm-svn: 163455
2012-09-08 04:26:37 +00:00
Ted Kremenek 722398f1d4 Fix analyzer tests.
llvm-svn: 162588
2012-08-24 20:39:55 +00:00
Anna Zaks b60908db3a [analyzer] Add experimental "issue hash" to the plist diagnostic.
CmpRuns.py can be used to compare issues from different analyzer runs.
Since it uses the issue line number to unique 2 issues, adding a new
line to the beginning of a file makes all issues in the file reported as
new. 

The hash will be an opaque value which could be used (along with the
function name) by CmpRuns to identify the same issues. This way, we only
fail to identify the same issue from two runs if the function it appears
in changes (not perfect, but much better than nothing).

llvm-svn: 158180
2012-06-08 00:04:43 +00:00
Ted Kremenek 54baf2e57d PlistDiagnostics: force the ranges for control-flow edges to be single locations, forcing
adjacent edges to have compatible ranges.  This simplifies the layout logic for some clients.

llvm-svn: 158028
2012-06-05 22:00:52 +00:00
Ted Kremenek a85f38ba3a Rework ExprEngine::evalLoad and clients (e.g. VisitBinaryOperator) so that when we generate a new ExplodedNode
we use the same Expr* as the one being currently visited.  This is preparation for transitioning to having
ProgramPoints refer to CFGStmts.

This required a bit of trickery.  We wish to keep the old Expr* bindings in the Environment intact,
as plenty of logic relies on it and there is no reason to change it, but we sometimes want the Stmt* for
the ProgramPoint to be different than the Expr* being used for bindings.  This requires adding an extra
argument for some functions (e.g., evalLocation).  This looks a bit strange for some clients, but
it will look a lot cleaner when were start using CFGStmt* in the appropriate places.

As some fallout, the diagnostics arrows are a bit difference, since some of the node locations have changed.
I have audited these, and they look reasonable.

llvm-svn: 154214
2012-04-06 22:10:18 +00:00
Ted Kremenek 5a10f08b52 Include the "issue context" (e.g. function or method) where a static analyzer issue occurred in the plist output.
Fixes <rdar://problem/11004527>

llvm-svn: 154030
2012-04-04 18:11:35 +00:00
Ted Kremenek 1e809b4c4c [analyzer] Implement basic path diagnostic pruning based on "interesting" symbols and regions.
Essentially, a bug centers around a story for various symbols and regions.  We should only include
the path diagnostic events that relate to those symbols and regions.

The pruning is done by associating a set of interesting symbols and regions with a BugReporter, which
can be modified at BugReport creation or by BugReporterVisitors.

This patch reduces the diagnostics emitted in several of our test cases.  I've vetted these as
having desired behavior.  The only regression is a missing null check diagnostic for the return
value of realloc() in test/Analysis/malloc-plist.c.  This will require some investigation to fix,
and I have added a FIXME to the test case.

llvm-svn: 152361
2012-03-09 01:13:14 +00:00
Anna Zaks 16f3831064 [analyzer] Retain release: drop the line number info from the leak
message.

llvm-svn: 151657
2012-02-28 21:49:08 +00:00
Anna Zaks 819b0d8619 [analyzer] Fix a bug in RetainReleaseChecker diagnostics. It gives more precise error message on the modified test case (and prevents duplicate diagnostics when we purge at block granularity).
llvm-svn: 140840
2011-09-30 02:19:19 +00:00
Anna Zaks efd182d992 [analyzer] Refactor: make PathDiagnosticLocation responsible for validation of SourceLocations (commit 5 of ?):
- Get rid of PathDiagnosticLocation(SourceRange r,..) constructor by providing a bunch of create methods.
 - The PathDiagnosticLocation(SourceLocation L,..), which is used by crate methods, will eventually become private.
 - Test difference is in the case when the report starts at the beginning of the function. We used to represent that point as a range of the very first token in the first statement. Now, it's just a single location representing the first character of the first statement.

llvm-svn: 139932
2011-09-16 19:18:30 +00:00
Anna Zaks 207c68012a [analyzer] Refactor: make PathDiagnosticLocation responsible for validation of SourceLocations (commit 4 of ?):
- The closing brace is always a single location, not a range.
 - The test case previously had a location key 57:1 followed by a range [57:1 - 57:1]. 

llvm-svn: 139832
2011-09-15 20:06:34 +00:00
Anna Zaks 615e3a69c3 [analyzer] After CFG has been linearized, we can have a situation where an ExpoledNode has an invalid SourceLocation (which has no correspondence in the source code). This commit is the first step to solve this problem.
- It adds LocationContext to the PathDiagnosticLocation object and uses it to lookup the enclosing statement with a valid location.
 - So far, the LocationContext is only available when the object is constructed from the ExplodedNode.
 - Already found some subtle bugs(in plist-output-alternate.m) where the intermediate diagnostic steps were not previously shown. 

llvm-svn: 139703
2011-09-14 17:48:01 +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 3f955e6d89 [analyzer] rename all experimental checker packages to have 'experimental' be the common root package.
llvm-svn: 136835
2011-08-03 23:14:55 +00:00
Ted Kremenek e9fda1e48a [analyzer] Overhaul how the static analyzer expects CFGs by forcing CFGs to be linearized only when used by the static analyzer. This required a rewrite of LiveVariables, and exposed a ton of subtle bugs.
The motivation of this large change is to drastically simplify the logic in ExprEngine going forward.

Some fallout is that the output of some BugReporterVisitors is not as accurate as before; those will
need to be fixed over time.  There is also some possible performance regression as RemoveDeadBindings
will be called frequently; this can also be improved over time.

llvm-svn: 136419
2011-07-28 23:07:59 +00:00
Ted Kremenek f230198f15 Tighen analyzer diagnostics w.r.t ObjC/CF leaks.
llvm-svn: 132130
2011-05-26 18:45:44 +00:00
Argyrios Kyrtzidis 9eb02dfa89 [analyzer] Remove '-analyzer-check-objc-mem' flag, the nominee for best misnomer award.
llvm-svn: 126676
2011-02-28 19:49:42 +00:00
Argyrios Kyrtzidis 2c49ec7f1d [analyzer] Migrate NSErrorChecker and DereferenceChecker to CheckerV2.
They cooperate in that NSErrorChecker listens for ImplicitNullDerefEvent events that
DereferenceChecker can dispatch.
ImplicitNullDerefEvent is when we dereferenced a location that may be null.

llvm-svn: 126659
2011-02-28 17:36:18 +00:00
Argyrios Kyrtzidis b388f77ad9 [analyzer] Remove '-analyzer-experimental-internal-checks' flag, it doesn't have any checkers associated with it anymore.
llvm-svn: 126440
2011-02-24 21:43:08 +00:00
Ted Kremenek 731310e13e Tweak null dereference checker to give better diagnostics for null dereferences resulting from array accesses.
llvm-svn: 117334
2010-10-26 00:06:13 +00:00
Ted Kremenek 4f63ac7057 Tweak retain/release checker diagnostics to specify a leak occurs because an object is not referenced later in the path,
not that it isn't referenced later in the code.  Fixes <rdar://problem/8527839>.

llvm-svn: 116636
2010-10-15 22:50:23 +00:00
Ted Kremenek ff3a4ff6e9 Use FindReportInEquivalenceClass to identify all the nodes used for the trimmed graph (in BugReporter). This fixes a problem where a leak that happened to occur on both an exit() path and a non-exit() path was getting reported with the exit() path (which users don't care about).
This fixes:

<rdar://problem/8331641> leak reports should not show paths that end with exit() (but ones that don't end with exit())

llvm-svn: 113524
2010-09-09 19:05:34 +00:00
Ted Kremenek 5f256da834 Rename GRState::getSVal() -> getRawSVal() and getSimplifiedSVal() -> getSVal().
The end result is now we eagarly constant-fold symbols in the analyzer that are perfectly constrained
to be a constant value.  This allows us to recover some path-sensitivity in some cases by lowering
the required level of reasoning power needed to evaluate some expressions.

The net win from this change is that the false positive in PR 8015 is fixed, and we also
find more idempotent operations bugs.

We do, however, regress with the BugReporterVisitors, which need to be modified to understand
this constant folding (and look past it).  This causes some diagnostic regressions in plist-output.m
which will get addressed in a future patch.  plist-output.m is now marked XFAIL, while
plist-output-alternate.m now tests that the plist output is working, but with the suboptimal
diagnostics.  This second test file will eventually be removed.

llvm-svn: 113477
2010-09-09 07:13:00 +00:00