Commit Graph

92 Commits

Author SHA1 Message Date
Jordan Rose fa92f0f298 [analyzer] Always allow BugReporterVisitors to see the bug path.
Before, PathDiagnosticConsumers that did not support actual path output
would (sensibly) cause the generation of the full path to be skipped.
However, BugReporterVisitors may want to see the path in order to mark a
BugReport as invalid.

Now, even for a path generation scheme of 'None' we will still create a
trimmed graph and walk backwards through the bug path, doing no work other
than passing the nodes to the BugReporterVisitors. This isn't cheap, but
it's necessary to properly do suppression when the first path consumer does
not support path notes.

In the future, we should try only generating the path and visitor-provided
path notes once, or at least only creating the trimmed graph once.

llvm-svn: 164447
2012-09-22 01:24:56 +00:00
Jordan Rose 5a751b993f [analyzer] Allow a BugReport to be marked "invalid" during path generation.
This is intended to allow visitors to make decisions about whether a
BugReport is likely a false positive. Currently there are no visitors
making use of this feature, so there are no tests.

When a BugReport is marked invalid, the invalidator must provide a key
that identifies the invaliation (intended to be the visitor type and a
context pointer of some kind). This allows us to reverse the decision
later on. Being able to reverse a decision about invalidation gives us more
flexibility, and allows us to formulate conditions like "this report is
invalid UNLESS the original argument is 'foo'". We can use this to
fine-tune our false-positive suppression (coming soon).

llvm-svn: 164446
2012-09-22 01:24:53 +00:00
Ted Kremenek 14f779c4d6 Implement faux-body-synthesis of well-known functions in the static analyzer when
their implementations are unavailable.  Start by simulating dispatch_sync().

This change is largely a bunch of plumbing around something very simple.  We
use AnalysisDeclContext to conjure up a fake function body (using the
current ASTContext) when one does not exist.  This is controlled
under the analyzer-config option "faux-bodies", which is off by default.

The plumbing in this patch is largely to pass the necessary machinery
around.  CallEvent needs the AnalysisDeclContextManager to get
the function definition, as one may get conjured up lazily.

BugReporter and PathDiagnosticLocation needed to be relaxed to handle
invalid locations, as the conjured body has no real source locations.
We do some primitive recovery in diagnostic generation to generate
some reasonable locations (for arrows and events), but it can be
improved.

llvm-svn: 164339
2012-09-21 00:09:11 +00:00
Jordan Rose 5297748e3f [analyzer] Fix another use of the address of a temporary, like r163402.
Again, GCC is more aggressive about reusing temporary space than we are,
leading to Release build crashes for this undefined behavior.

PR13710 (though it may not be the only problem there)

llvm-svn: 163747
2012-09-12 22:48:08 +00:00
Ted Kremenek ba22a035ad Fix regression where "looping back to the head of" PathDiagnosticEvents
were not emitted.

Fixes <rdar://problem/12280665>.

llvm-svn: 163683
2012-09-12 06:22:18 +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
Jordan Rose cc0b1bfa56 [analyzer] Ensure that PathDiagnostics profile the same regardless of path.
PathDiagnostics are actually profiled and uniqued independently of the
path on which the bug occurred. This is used to merge diagnostics that
refer to the same issue along different paths, as well as by the plist
diagnostics to reference files created by the HTML diagnostics.

However, there are two problems with the current implementation:

1) The bug description is included in the profile, but some
   PathDiagnosticConsumers prefer abbreviated descriptions and some
   prefer verbose descriptions. Fixed by including both descriptions in
   the PathDiagnostic objects and always using the verbose one in the profile.

2) The "minimal" path generation scheme provides extra information about
   which events came from macros that the "extensive" scheme does not.
   This resulted not only in different locations for the plist and HTML
   diagnostics, but also in diagnostics being uniqued in the plist output
   but not in the HTML output. Fixed by storing the "end path" location
   explicitly in the PathDiagnostic object, rather than trying to find the
   last piece of the path when the diagnostic is requested.

This should hopefully finish unsticking our internal buildbot.

llvm-svn: 162965
2012-08-31 00:36:26 +00:00
Anna Zaks 5d4ec36323 [analyzer] Improved diagnostic pruning for calls initializing values.
This heuristic addresses the case when a pointer (or ref) is passed
to a function, which initializes the variable (or sets it to something
other than '0'). On the branch where the inlined function does not
set the value, we report use of undefined value (or NULL pointer
dereference). The access happens in the caller and the path
through the callee would get pruned away with regular path pruning. To
solve this issue, we previously disabled diagnostic pruning completely
on undefined and null pointer dereference checks, which entailed very
verbose diagnostics in most cases. Furthermore, not all of the
undef value checks had the diagnostic pruning disabled.

This patch implements the following heuristic: if we pass a pointer (or
ref) to the region (on which the error is reported) into a function and
it's value is either undef or 'NULL' (and is a pointer), do not prune
the function.

llvm-svn: 162863
2012-08-29 21:22:37 +00:00
Ted Kremenek 9bf9af92a4 Allow multiple PathDiagnosticConsumers to be used with a BugReporter at the same time.
This fixes several issues:

- removes egregious hack where PlistDiagnosticConsumer would forward to HTMLDiagnosticConsumer,
but diagnostics wouldn't be generated consistently in the same way if PlistDiagnosticConsumer
was used by itself.

- emitting diagnostics to the terminal (using clang's diagnostic machinery) is no longer a special
case, just another PathDiagnosticConsumer.  This also magically resolved some duplicate warnings,
as we now use PathDiagnosticConsumer's diagnostic pruning, which has scope for the entire translation
unit, not just the scope of a BugReporter (which is limited to a particular ExprEngine).

As an interesting side-effect, diagnostics emitted to the terminal also have their trailing "." stripped,
just like with diagnostics emitted to plists and HTML.  This required some tests to be updated, but now
the tests have higher fidelity with what users will see.

There are some inefficiencies in this patch.  We currently generate the report graph (from the ExplodedGraph)
once per PathDiagnosticConsumer, which is a bit wasteful, but that could be pulled up higher in the
logic stack.  There is some intended duplication, however, as we now generate different PathDiagnostics (for the same issue)
for different PathDiagnosticConsumers.  This is necessary to produce the diagnostics that a particular
consumer expects.

llvm-svn: 162028
2012-08-16 17:45:23 +00:00
Anna Zaks 4c03dfd4b1 [analyzer] Solve another source of non-determinism in the diagnostic
engine.

The code that was supposed to split the tie in a deterministic way is
not deterministic. Most likely one of the profile methods uses a
pointer. After this change we do finally get the consistent diagnostic
output. Testing this requires running the analyzer on large code bases
and diffing the results.

llvm-svn: 161224
2012-08-02 23:41:05 +00:00
Anna Zaks 4c4fe84b25 [analyzer] Flush bug reports in deterministic order.
This makes the diagnostic output order deterministic. 
1) This makes order of text diagnostics consistent from run to run.

2) Also resulted in different bugs being reported (from one run to
another) with plist-html output.

llvm-svn: 161151
2012-08-02 00:41:43 +00:00
Jordan Rose a4c0d21f42 [analyzer] Show paths for destructor calls.
This modifies BugReporter and friends to handle CallEnter and CallExitEnd
program points that came from implicit call CFG nodes (read: destructors).

This required some extra handling for nested implicit calls. For example,
the added multiple-inheritance test case has a call graph that looks like this:

testMultipleInheritance3
  ~MultipleInheritance
    ~SmartPointer
    ~Subclass
      ~SmartPointer
        ***bug here***

In this case we correctly notice that we started in an inlined function
when we reach the CallEnter program point for the second ~SmartPointer.
However, when we reach the next CallEnter (for ~Subclass), we were
accidentally re-using the inner ~SmartPointer call in the diagnostics.

Rather than guess if we saw the corresponding CallExitEnd based on the
contents of the active path, we now just ask the PathDiagnostic if there's
any known stack before popping off the top path.

(A similar issue could have occured without multiple inheritance, but there
wasn't a test case for it.)

llvm-svn: 160804
2012-07-26 20:04:05 +00:00
Jordan Rose fbe6dba15a [analyzer] Make CallEnter, CallExitBegin, and CallExitEnd not be StmtPoints
These ProgramPoints are used in inlining calls,
and not all calls have associated statements anymore.

llvm-svn: 160021
2012-07-10 22:07:52 +00:00
Ted Kremenek 16704bb15b Allow some BugReports to opt-out of PathDiagnostic callstack pruning until we have significantly
improved the pruning heuristics.  The current heuristics are pretty good, but they make diagnostics
for uninitialized variables warnings particularly useless in some cases.

llvm-svn: 157734
2012-05-31 06:03:17 +00:00
Ted Kremenek 170641b0e0 Refine analyzer diagnostics by adding an expression "cone-of-influence" to reverse track interesting
values through interesting expressions.  This allows us to map from interesting values in a caller
to interesting values in a caller, thus recovering some precision in diagnostics lost from IPA.

Fixes <rdar://problem/11327497>

llvm-svn: 155971
2012-05-02 00:31:29 +00:00
Anna Zaks 7e53bd6fb0 [analyzer] Run remove dead bindings right before leaving a function.
This is needed to ensure that we always report issues in the correct
function. For example, leaks are identified when we call remove dead
bindings. In order to make sure we report a callee's leak in the callee,
we have to run the operation in the callee's context.

This change required quite a bit of infrastructure work since:
 - We used to only run remove dead bindings before a given statement;
here we need to run it after the last statement in the function. For
this, we added additional Program Point and special mode in the
SymbolReaper to remove all symbols in context lower than the current
one.
 - The call exit operation turned into a sequence of nodes, which are
now guarded by CallExitBegin and CallExitEnd nodes for clarity and
convenience.

(Sorry for the long diff.)

llvm-svn: 155244
2012-04-20 21:59:08 +00:00
Ted Kremenek b45d198b6f Require that all static analyzer issues have a category. As part of this change,
consolidate some commonly used category strings into global references (more of this can be done, I just did a few).

Fixes <rdar://problem/11191537>.

llvm-svn: 154121
2012-04-05 20:43:28 +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 56458cab04 Change BugReporter's usage of IsCachedDiagnostic to only impact pruning diagnostics emitted to the
console, and leave it up to PathDiagnosticConsumer to unique reports with the shortest path.

llvm-svn: 153987
2012-04-04 00:55:29 +00:00
Benjamin Kramer ac19edd2b0 Analyzer: Store BugReports directly in a ilist instead of adding another layer of inderection with std::list
llvm-svn: 153847
2012-04-01 19:30:51 +00:00
Ted Kremenek 41daf12e2c Fix suspicious comparison reported by PVS-Studio!
llvm-svn: 153568
2012-03-28 05:24:50 +00:00
Jordy Rose 43a9af7352 [analyzer] Restart path diagnostic generation if any of the visitors change the report configuration while walking the path.
This required adding a change count token to BugReport, but also allowed us to ditch ImmutableList as the BugReporterVisitor data type.

Also, remove the hack from MallocChecker, now that visitors appear in the opposite order. This is not exactly a fix, but the common case -- custom diagnostics after generic ones -- is now the default behavior.

llvm-svn: 153369
2012-03-24 03:03:29 +00:00
NAKAMURA Takumi 3ec7c4574f StaticAnalyzer: Fix abuse of StringRef in r152962.
llvm-svn: 152982
2012-03-17 13:06:05 +00:00
Anna Zaks cba4f298c6 [analyzer] Create symbol-aware stack hints (building upon r152837).
The symbol-aware stack hint combines the checker-provided message
with the information about how the symbol was passed to the callee: as
a parameter or a return value.

For malloc, the generated messages look like this :
"Returning from 'foo'; released memory via 1st parameter"
"Returning from 'foo'; allocated memory via 1st parameter"
"Returning from 'foo'; allocated memory returned"
"Returning from 'foo'; reallocation of 1st parameter failed"


(We are yet to handle cases when the symbol is a field in a struct or
an array element.)

llvm-svn: 152962
2012-03-16 23:24:20 +00:00
Jordy Rose 735724fb1e [analyzer] If a metadata symbol is interesting, its region is interesting as well.
llvm-svn: 152868
2012-03-15 22:45:29 +00:00
Anna Zaks 1ff57d57e8 [analyzer] Allow checkers to supply call stack diagnostic hints for the
BugVisitor DiagnosticPieces.

When checkers create a DiagnosticPieceEvent, they can supply an extra
string, which will be concatenated with the call exit message for every
call on the stack between the diagnostic event and the final bug report.
(This is a simple version, which could be/will be further enhanced.)

For example, this is used in Malloc checker to produce the ",
which allocated memory" in the following example:

static char *malloc_wrapper() { // 2. Entered call from 'use'
    return malloc(12);    // 3. Memory is allocated
}

void use() {
    char *v;
    v = malloc_wrapper(); // 1. Calling 'malloc_wrappers'
        // 4. Returning from 'malloc_wrapper', which allocated memory
}                         // 5. Memory is never released; potential
memory leak

llvm-svn: 152837
2012-03-15 21:13:02 +00:00
Anna Zaks d4e9059fe0 [analyzer] Diagnostics: Supply Caller information even if the bug occurs
in the callee.

llvm-svn: 152734
2012-03-14 18:58:28 +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
Ted Kremenek 04e860df2c [analyzer] add a diagnostic event when entering a call via inlining, within the callee, and add an edge.
llvm-svn: 152086
2012-03-06 01:25:01 +00:00
Ted Kremenek 024ba20bef [analyzer] 'Looping back to the head of the loop' diagnostics are prunable.
llvm-svn: 152083
2012-03-06 01:00:36 +00:00
Ted Kremenek aa1f96add5 [analyzer diagnostics] flush locations *before* popping the current path when visiting a CallEnter.
Fixes <rdar://problem/10967815>

llvm-svn: 151938
2012-03-02 21:16:22 +00:00
Ted Kremenek f9e9d33019 [analyzer diagnostics] Change CompactPathDiagnostic to recursively compact diagnostics in calls into macro pieces.
Also fix handling of macros within calls in the HTMLDiagnostics.

This also adds a test case for r151774.

llvm-svn: 151872
2012-03-02 01:27:31 +00:00
Anna Zaks ec9c4e487c [analyzer] Diagnostics - do not try to cleanup the path with macros, it
will be done by the general cleanup later on.
A Patch by Ted.

llvm-svn: 151784
2012-03-01 01:30:58 +00:00
Ted Kremenek 0a8e00d493 Change if...else if...else if... to a switch.
llvm-svn: 151775
2012-03-01 00:05:06 +00:00
Ted Kremenek 2429c6ffe7 [analyzer diagnostics] start prototyping stripping PathDiagnostics of unnecessary cruft caused by path inlining.
This introduces a concept of a "prunable" PathDiagnosticEvent.  Currently this is a flag, but
we may evolve the concept to make this more dynamically inferred.

llvm-svn: 151663
2012-02-28 23:06:21 +00:00
Ted Kremenek 1bf3b04726 Make PathDiagnosticBuilder sensitive to varying LocationContexts, thus fixing a bug in the inlining diagnostics where the wrong location could be used.
llvm-svn: 151349
2012-02-24 07:12:52 +00:00
Ted Kremenek 60a7820ffe Reapply r151317, but when computing the PathDiagnostic profile and size keep into account the nested structure. Also fix a problem with how
inlining impacted Plist diagnostics, and adjust some ranges in the Plist output due to richer information.

llvm-svn: 151346
2012-02-24 06:00:00 +00:00
Chad Rosier c0ea158a2b Revert r151317 - Rework PathDiagnostics creation.. - to appease buildbots.
llvm-svn: 151338
2012-02-24 02:06:33 +00:00
Ted Kremenek f2131e7d95 Rework PathDiagnostic creation so that call stacks are captured by a nested PathDiagnosticCallPiece.
llvm-svn: 151317
2012-02-24 00:38:56 +00:00
Anna Zaks df901a4419 [analyzer] Malloc: unique leak reports by allocation site.
When we find two leak reports with the same allocation site, report only
one of them.

Provide a helper method to BugReporter to facilitate this.

llvm-svn: 151287
2012-02-23 21:38:21 +00:00
Dylan Noblesmith c95d81924d Basic: import IntrusiveRefCntPtr<> into clang namespace
The class name is long enough without the llvm:: added.
Also bring in RefCountedBase and RefCountedBaseVPTR.

llvm-svn: 150958
2012-02-20 14:00:23 +00:00
Ted Kremenek 7df15cd21f Remove explicit delete of PathDiagnosticMacroPiece, as it is now reference counted.
llvm-svn: 150110
2012-02-08 22:48:17 +00:00
Ted Kremenek afa6e249cb Change PathDiagnosticPieces to be reference counted (simplifying their management), and introduce 'PathPieces' as a common container for PathDiagnosticPieces.
llvm-svn: 150054
2012-02-08 04:32:34 +00:00
Benjamin Kramer 7ec12c928a Revert my patches which removed Diagnostic.h includes by moving some operator overloads out of line.
This seems to negatively affect compile time onsome ObjC tests
(which use a lot of partial diagnostics I assume). I have to come
up with a way to keep them inline without including Diagnostic.h
everywhere. Now adding a new diagnostic requires a full rebuild
of e.g. the static analyzer which doesn't even use those diagnostics.

This reverts commit 6496bd10dc3a6d5e3266348f08b6e35f8184bc99.
This reverts commit 7af19b817ba964ac560b50c1ed6183235f699789.
This reverts commit fdd15602a42bbe26185978ef1e17019f6d969aa7.
This reverts commit 00bd44d5677783527d7517c1ffe45e4d75a0f56f.
This reverts commit ef9b60ffed980864a8db26ad30344be429e58ff5.

llvm-svn: 150006
2012-02-07 22:29:24 +00:00
Ted Kremenek 7d88ff436b Tweak BugReporter extensive diagnostics to not add edges between function calls.
llvm-svn: 149959
2012-02-07 02:26:17 +00:00
Ted Kremenek a2bbac3ffc Add basic BugReporter support for CallEnter/CallExit. WIP.
llvm-svn: 149939
2012-02-07 00:24:33 +00:00
Dylan Noblesmith 2c1dd2716a Basic: import SmallString<> into clang namespace
(I was going to fix the TODO about DenseMap too, but
that would break self-host right now. See PR11922.)

llvm-svn: 149799
2012-02-05 02:13:05 +00:00
Dylan Noblesmith e27789991d Basic: import OwningPtr<> into clang namespace
llvm-svn: 149798
2012-02-05 02:12:40 +00:00
Benjamin Kramer 4903802fbf Move a method from IdentifierTable.h out of line and remove the SmallString include.
Fix all the transitive include users.

llvm-svn: 149783
2012-02-04 13:45:25 +00:00
Benjamin Kramer 3307c508c9 Move various diagnostic operator<< overloads out of line and remove includes of Diagnostic.h.
Fix all the files that depended on transitive includes of Diagnostic.h.
With this patch in place changing a diagnostic no longer requires a full rebuild of the StaticAnalyzer.

llvm-svn: 149781
2012-02-04 12:31:12 +00:00