Commit Graph

2035 Commits

Author SHA1 Message Date
Jordan Rose cb6a721920 [analyzer] -drain is not an alias for -release.
This was previously added to support -[NSAutoreleasePool drain], which
behaves like -release under non-GC and "please collect" under GC. We're
not currently modeling the autorelease pool stack, though, so we can
just take this out entirely.

Fixes PR14927.

llvm-svn: 172444
2013-01-14 18:58:33 +00:00
Ted Kremenek 4e9a2dbde5 Refine analyzer's handling of unary '!' and floating types to not assert.
Fixes PR 14634 and <rdar://problem/12903080>.

llvm-svn: 172274
2013-01-11 23:36:25 +00:00
Ted Kremenek 039fac0347 Correctly propagate uninitialized values within logical expressions.
Fixes assertion failure reported in PR 14635 and
<rdar://problem/12902945> respectively.

llvm-svn: 172263
2013-01-11 22:35:39 +00:00
Anna Zaks 39a7692091 [analyzer] Rename the warning: state the issue before the hint of how it
can be fixed

llvm-svn: 172170
2013-01-11 03:52:44 +00:00
Anna Zaks ca49e535ae [analyzer]Recognize ivar invalidation protocol even if it was redeclared
This will get rid of some false positives as well as false negatives.

llvm-svn: 172169
2013-01-11 03:52:40 +00:00
Anna Zaks 2975cf27e4 [analyzer] Ivar invalidation: track ivars declared in categories.
llvm-svn: 172168
2013-01-11 03:52:37 +00:00
Anna Zaks a96a9ef716 [analyzer] Allow IvarInvalidation checker to suppress warnings via
assertions.

To ensure that custom assertions/conditional would also be supported,
just check if the ivar that needs to be invalidated or set to nil is
compared against 0.

Unfortunately, this will not work for code containing 'assert(IvarName)'

llvm-svn: 172147
2013-01-10 23:34:16 +00:00
Anna Zaks 640123de5e [analyzer] Fix non-determinizm introduced in r172104.
In some cases, we just pick any ivar that needs invalidation and attach
the warning to it. Picking the first from DenseMap of pointer keys was
triggering non-deterministic output.

llvm-svn: 172134
2013-01-10 22:44:16 +00:00
Anna Zaks 0aeb60d79d [analyzer] Add more checks to the ObjC Ivar Invalidation checker.
Restructured the checker so that it could easily find two new classes of
issues:
 - when a class contains an invalidatable ivar, but no declaration of an
invalidation method
 - when a class contains an invalidatable ivar, but no definition of an
invalidation method in the @implementation.

The second case might trigger some false positives, for example, when
the method is defined in a category.

llvm-svn: 172104
2013-01-10 20:59:51 +00:00
Ted Kremenek 2f2edd3fb1 Do not model loads from complex types, since we don't accurately model the imaginary and real parts yet.
Fixes false positive reported in <rdar://problem/12964481>.

llvm-svn: 171987
2013-01-09 18:46:17 +00:00
Anna Zaks 454a384e59 [analyzer] Only include uniqueling location as issue_hash when available
This makes us more optimistic when matching reports in a changing code
base. Addresses Jordan's feedback for r171825.

llvm-svn: 171884
2013-01-08 19:19:46 +00:00
Anna Zaks a043d0cef2 [analyzer] Include the bug uniqueing location in the issue_hash.
The issue here is that if we have 2 leaks reported at the same line for
which we cannot print the corresponding region info, they will get
treated as the same by issue_hash+description. We need to AUGMENT the
issue_hash with the allocation info to differentiate the two issues.

Add the "hash" (offset from the beginning of a function) representing
allocation site to solve the issue.

We might want to generalize solution in the future when we decide to
track more than just the 2 locations from the diagnostics.

llvm-svn: 171825
2013-01-08 00:25:29 +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
Anna Zaks 030e65d1b2 [analyzer] Fix a false positive in Secure Keychain API checker.
Better handle the blacklisting of known bad deallocators when symbol
escapes through a call to CFStringCreateWithBytesNoCopy.

Addresses radar://12702952.

llvm-svn: 171770
2013-01-07 19:13:00 +00:00
Anna Zaks 5f37643de1 [analyzer] Fix a false positive in the ivar invalidation checker.
When a property is "inherited" through both a parent class and directly
through a protocol, we should not require the child to invalidate it
since the backing ivar belongs to the parent class.
(Fixes radar://12913734)

llvm-svn: 171769
2013-01-07 19:12:56 +00:00
Will Dietz df9a2bbcb1 CFG.cpp: Fix wrapping logic when printing block preds/succs.
First check only wrapped with i==8, second wrapped at i==2,8,18,28,...
This fix restores the intended behavior: i==8,18,28,...

Found with -fsanitize=integer.

llvm-svn: 171718
2013-01-07 09:51:17 +00:00
Ted Kremenek 1d6aac5b6a Fix capitalization of Objective-C in diagnostic.
llvm-svn: 171440
2013-01-03 01:30:20 +00:00
Anna Zaks 3fdcc0bda3 [analyzer] Rename callback EndPath -> EndFunction
This better reflects when callback is called and what the checkers
are relying on. (Both names meant the same pre-IPA.)

llvm-svn: 171432
2013-01-03 00:25:29 +00:00
Ted Kremenek c632467e2b Fix typo: objc_no_direct_instance_variable_assignmemt => objc_no_direct_instance_variable_assignment.
Fixes <rdar://problem/12927551>.

llvm-svn: 170971
2012-12-22 00:34:48 +00:00
Anna Zaks 1ee76c1bae [analyzer] Re-apply r170826 and make the dumping of the GallGraph
deterministic.

Commit message for r170826:

[analyzer] Traverse the Call Graph in topological order.

Modify the call graph by removing the parentless nodes. Instead all
nodes are children of root to ensure they are all reachable. Remove the
tracking of nodes that are "top level" or global. This information is
not used and can be obtained from the Decls stored inside
CallGraphNodes.

Instead of existing ordering hacks, analyze the functions in topological
order over the Call Graph.

Together with the addition of devirtualizable ObjC message sends and
blocks to the call graph, this gives around 6% performance improvement
on several large ObjC benchmarks.

llvm-svn: 170906
2012-12-21 17:27:01 +00:00
Rafael Espindola e7ec558f25 Revert r170826. The output of
./bin/clang -cc1 -internal-isystem /home/espindola/llvm/build/lib/clang/3.3/include/ -analyze -analyzer-checker=debug.DumpCallGraph /home/espindola/llvm/clang/test/Analysis/debug-CallGraph.c -fblocks

changes in each run.

llvm-svn: 170829
2012-12-21 01:30:23 +00:00
Anna Zaks 77ca7f1bbe [analyzer] Traverse the Call Graph in topological order.
Modify the call graph by removing the parentless nodes. Instead all
nodes are children of root to ensure they are all reachable. Remove the
tracking of nodes that are "top level" or global. This information is
not used and can be obtained from the Decls stored inside
CallGraphNodes.

Instead of existing ordering hacks, analyze the functions in topological
order over the Call Graph.

Together with the addition of devirtualizable ObjC message sends and
blocks to the call graph, this gives around 6% performance improvement
on several large ObjC benchmarks.

llvm-svn: 170826
2012-12-21 01:19:22 +00:00
Argyrios Kyrtzidis cbfd4d2483 Use some heuristics so that when a fixit removes a source range, we try
to also remove a trailing space if possible.

For example, removing '__bridge' from:

i = (__bridge I*)p;

should result in:

i = (I*)p;

not:

i = ( I*)p;

rdar://11314821

llvm-svn: 170764
2012-12-20 21:05:53 +00:00
Ted Kremenek 89abaa3517 Update RetainCountChecker to understand attribute ns_returns_autoreleased.
Fixes <rdar://problem/12887356>.

llvm-svn: 170724
2012-12-20 19:36:22 +00:00
Anna Zaks ad3704c96a [analyzer] Tweak the NumFunctionsAnalyzed stat so that it's more useful.
llvm-svn: 170362
2012-12-17 20:08:54 +00:00
Anna Zaks d53182b0df [analyzer] Implement "do not inline large functions many times"
performance heuristic

After inlining a function with more than 13 basic blocks 32 times, we
are not going to inline it anymore. The idea is that inlining large
functions leads to drastic performance implications. Since the function
has already been inlined, we know that we've analyzed it in many
contexts. 

The following metrics are used:
 - Large function is a function with more than 13 basic blocks (we
should switch to another metric, like cyclomatic complexity)
 - We consider that we've inlined a function many times if it's been
inlined 32 times. This number is configurable with -analyzer-config
max-times-inline-large=xx

This heuristic addresses a performance regression introduced with
inlining on one benchmark. The analyzer on this benchmark became 60
times slower with inlining turned on. The heuristic allows us to analyze
it in 24% of the time. The performance improvements on the other
benchmarks I've tested with are much lower - under 10%, which is
expected.

llvm-svn: 170361
2012-12-17 20:08:51 +00:00
Jordan Rose b0fe7fdb57 [analyzer] Generalize ObjCMissingSuperCallChecker.
We now check a few methods for UIResponder, NSResponder, and NSDocument.

Patch by Julian Mayer!

llvm-svn: 170089
2012-12-13 03:06:45 +00:00
Anna Zaks 3f12949b25 [analyzer] Fix a self-init checker false positive.
This is a Band-Aid fix to a false positive, where we complain about not
initializing self to [super init], where self is not coming from the
init method, but is coming from the caller to init.

The proper solution would be to associate the self and it's state with
the enclosing init.

llvm-svn: 170059
2012-12-13 00:42:19 +00:00
Jordan Rose 4cfdbff3c7 [analyzer] Don't crash running destructors for multidimensional arrays.
We don't handle array destructors correctly yet, but we now apply the same
hack (explicitly destroy the first element, implicitly invalidate the rest)
for multidimensional arrays that we already use for linear arrays.

<rdar://problem/12858542>

llvm-svn: 170000
2012-12-12 19:13:44 +00:00
Anna Zaks a7b1c47c1a [analyzer] Don't generate a summary for "freeWhenDone" if method is
inlined.

Fixes a false positive that occurs if a user writes their own
initWithBytesNoCopy:freeWhenDone wrapper.

llvm-svn: 169795
2012-12-11 00:17:53 +00:00
Anna Zaks 5d484780fb [analyzer] Optimization heuristic: do not reanalyze every ObjC method as
top level.

This heuristic is already turned on for non-ObjC methods
(inlining-mode=noredundancy). If a method has been previously analyzed,
while being inlined inside of another method, do not reanalyze it as top
level.

This commit applies it to ObjCMethods as well. The main caveat here is
that to catch the retain release errors, we are still going to reanalyze
all the ObjC methods but without inlining turned on.

Gives 21% performance increase on one heavy ObjC benchmark, which
suffered large performance regressions due to ObjC inlining.

llvm-svn: 169639
2012-12-07 21:51:47 +00:00
Jordan Rose 9a33913645 [analyzer] Fix r168019 to work with unpruned paths as well.
This is the case where the analyzer tries to print out source locations
for code within a synthesized function body, which of course does not have
a valid source location. The previous fix attempted to do this during
diagnostic path pruning, but some diagnostics have pruning disabled, and
so any diagnostic with a path that goes through a synthesized body will
either hit an assertion or emit invalid output.

<rdar://problem/12657843> (again)

llvm-svn: 169631
2012-12-07 19:56:29 +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 3e871d8cf6 Use the BlockDecl captures list to infer the direct captures for a BlockDataRegion. Fixes <rdar://problem/12415065>.
We still need to do a recursive walk to determine all static/global variables
referenced by a block, which is needed for region invalidation.

llvm-svn: 169481
2012-12-06 07:17:26 +00:00
Richard Smith afa874d4c0 This test used to fail forever if it failed once, because it does not clean up after itself if it failed.
llvm-svn: 169356
2012-12-05 06:16:54 +00:00
Anna Zaks 25dd07c112 [analyzer] Implement an opt-in variant of direct ivar assignment.
This will only check the direct ivar assignments in the annotated
methods.

llvm-svn: 169349
2012-12-05 01:14:37 +00:00
Ted Kremenek 2317f30f4d Correctly handle IntegralToBool casts in C++ in the static analyzer. Fixes <rdar://problem/12759044>.
llvm-svn: 168843
2012-11-29 00:50:20 +00:00
Ted Kremenek 18035d7125 Fix another false positive due to a CXX temporary object appearing in a C initializer.
The stop-gap here is to just drop such objects when processing the InitListExpr.
We still need a better solution.

Fixes <rdar://problem/12755044>.

llvm-svn: 168757
2012-11-28 01:49:01 +00:00
Ted Kremenek 5092c73187 Provide stop-gap solution to crash reported in PR 14436.
This was also covered by <rdar://problem/12753384>.  The static analyzer
evaluates a CXXConstructExpr within an initializer expression and
RegionStore doesn't know how to handle the resulting CXXTempObjectRegion
that gets created.  We need a better solution than just dropping the
value, but we need to better understand how to implement the right
semantics here.

Thanks to Jordan for his help diagnosing the behavior here.

llvm-svn: 168741
2012-11-27 23:05:37 +00:00
Jordan Rose 3ba8c792e5 [analyzer] Fix test to work on non-LP64 systems.
Thanks for the original catch in r168303, Takumi.

llvm-svn: 168671
2012-11-27 02:37:49 +00:00
Anna Zaks e3beeaa5e7 [analyzer] Fix a crash reported in PR 14400.
The AllocaRegion did not have the superRegion (based on LocationContext)
as part of it's hash. As a consequence, the AllocaRegions from
different frames were uniqued to be the same region.

llvm-svn: 168599
2012-11-26 19:11:46 +00:00
NAKAMURA Takumi d05b01a8df clang/test: Suppress two tests on LLP64 target, Windows x64.
llvm-svn: 168303
2012-11-19 10:00:59 +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
Jordan Rose 90ba0218e2 [analyzer] Fix test case broken by previous commit.
llvm-svn: 168020
2012-11-15 02:17:09 +00:00
Jordan Rose 2d98b97e10 [analyzer] Make sure calls in synthesized functions have valid path locations.
We do this by using the "most recent" good location: if a synthesized
function 'A' calls another function 'B', the path notes for the call to 'B'
will be placed at the same location as the path note for calling 'A'.

Similarly, the call to 'A' will have a note saying "Entered call from...",
and now we just don't emit that (since the user doesn't have a body to look
at anyway).

Previously, we were doing this for the "Calling..." notes, but not for the
"Entered call from..." or "Returning to caller". This caused a crash when
the path entered and then exiting a call within a synthesized body.

<rdar://problem/12657843>

llvm-svn: 168019
2012-11-15 02:07:23 +00:00
Jordan Rose 27d126f97b [analyzer] Fix test in previous commit.
llvm-svn: 167995
2012-11-14 23:09:52 +00:00
Jordan Rose 5a29f3c05e [analyzer] Add a test case for printing a path note at a PreStmt point.
This is also a false-positive test case for <rdar://problem/12415065>.

<rdar://problem/12687586>

llvm-svn: 167994
2012-11-14 23:03:55 +00:00
Richard Trieu 560910c9b8 Improve -Wtautological-constant-out-of-range-compare by taking into account
type conversion between integers.  This allows the warning to be more accurate.

Also, turned the warning off in an analyzer test.  The relavent test cases
are covered by the tests in Sema.

llvm-svn: 167992
2012-11-14 22:50:24 +00:00
Anna Zaks a14c1d09f6 [analyzer] Address Jordan's code review for r167813.
This simplifies logic, fixes a bug, and adds a test case.
Thanks Jordan!

llvm-svn: 167868
2012-11-13 19:47:40 +00:00
Anna Zaks de13814a37 Add a test that shows that reporting a leak after failure to free is
tricky.

llvm-svn: 167814
2012-11-13 03:34:49 +00:00
Anna Zaks 67291b90f9 Fix a Malloc Checker FP by tracking return values from initWithCharacter
and other functions.

When these functions return null, the pointer is not freed by
them/ownership is not transfered. So we should allow the user to free
the pointer by calling another function when the return value is NULL.

llvm-svn: 167813
2012-11-13 03:18:01 +00:00
Ted Kremenek e6ee671e16 Fix bad CFG construction bug when handling C++ 'try' statements.
This code assigned the last created CFGBlock* to the variable 'Block',
which is a scratch variable which is null'ed out after a block is
completed.  By assigning the last created block to 'Block', we start
editing a completed block, inserting CFGStmts that should be in
another block.  This was the case with 'try'.  The test case that
showed this had a while loop inside a 'try', and the logic before
the while loop was being included as part of the "condition block"
for the loop.  This showed up as a bogus dead store, but could
have lots of implications.

Turns out this bug was replicated a few times within CFG.cpp, so
I went and fixed up those as well.

llvm-svn: 167788
2012-11-13 00:12:13 +00:00
Anna Zaks 6ec9c3cbc1 [analyzer] Follow up to r167762 - precisely determine the adjustment
conditions.

The adjustment is needed only in case of dynamic dispatch performed by
the analyzer - when the runtime declaration is different from the static
one.

Document this explicitly in the code (by adding a helper). Also, use
canonical Decls to avoid matching against the case where the definition
is different from found declaration.

This fix suppresses the testcase I added in r167762, so add another
testcase to make sure we do test commit r167762.

llvm-svn: 167780
2012-11-12 23:40:29 +00:00
Anna Zaks 4e255b62f1 [analyzer] Fix a regression (from r 165079): compare canonical types.
Suppresses a leak false positive (radar://12663777).

In addition, we'll need to rewrite the adjustReturnValue() method not to
return UnknownVal by default, but rather assert in cases we cannot
handle. To make it possible, we need to correctly handle some of the
edge cases we already know about.

llvm-svn: 167762
2012-11-12 22:06:24 +00:00
Jordan Rose 9eb409ace9 [analyzer] When invalidating symbolic offset regions, take fields into account.
Previously, RegionStore was being VERY conservative in saying that because
p[i].x and p[i].y have a concrete base region of 'p', they might overlap.
Now, we check the chain of fields back up to the base object and check if
they match.

This only kicks in when dealing with symbolic offset regions because
RegionStore's "base+offset" representation of concrete offset regions loses
all information about fields. In cases where all offsets are concrete
(s.x and s.y), RegionStore will already do the right thing, but mixing
concrete and symbolic offsets can cause bindings to be invalidated that
are known to not overlap (e.g. p[0].x and p[i].y).
This additional refinement is tracked by <rdar://problem/12676180>.

<rdar://problem/12530149>

llvm-svn: 167654
2012-11-10 01:40:08 +00:00
Jordan Rose 721567af3e [analyzer] Check that the argument to CFMakeCollectable is non-NULL.
Patch by Sean McBride!

llvm-svn: 167537
2012-11-07 17:12:37 +00:00
Anna Zaks 2ed5125502 [analyzer] Add symbol escapes logic to the SimpleStreamChecker.
llvm-svn: 167439
2012-11-06 04:20:57 +00:00
Anna Zaks 8d1f6ed9a8 [analyzer] Run remove dead on end of path.
This will simplify checkers that need to register for leaks. Currently,
they have to register for both: check dead and check end of path.

I've modified the SymbolReaper to consider everything on the stack dead
if the input StackLocationContext is 0.

(This is a bit disruptive, so I'd like to flash out all the issues
asap.)

llvm-svn: 167352
2012-11-03 02:54:20 +00:00
Anna Zaks 1e80d8b49c [analyzer] SimpleStreamChecker - remove evalAssume and other refinements
llvm-svn: 167099
2012-10-31 02:32:41 +00:00
Anna Zaks 7bd0674dea [analyzer]Don't invalidate const arguments when there is no
IdentifierInfo.

Ee: C++ copy constructors.
llvm-svn: 167092
2012-10-31 01:18:26 +00:00
Jordan Rose 9e068aaa6f [analyzer] Warn about reallocf with an allocation size of 0, like realloc.
Patch by Sean McBride!

llvm-svn: 166995
2012-10-30 01:37:16 +00:00
Jordan Rose 3c2f65a73d [analyzer] New checker for missing super calls in UIViewController subclasses.
This is a syntactic checker aimed at helping iOS programmers correctly
subclass and override the methods of UIViewController. While this should
eventually be covered by the 'objc_requires_super' attribute, this
checker can be used with the existing iOS SDKs without any header changes.

This new checker is currently named 'alpha.osx.cocoa.MissingSuperCall'.
Patch by Julian Mayer!

llvm-svn: 166993
2012-10-30 01:21:35 +00:00
Anna Zaks be70d4d0b4 [analyzer] Add SimpleStreamChecker.
This is an example checker for catching fopen fclose API misuses.

llvm-svn: 166976
2012-10-29 22:51:50 +00:00
Jordan Rose ec44ac6a59 [analyzer] New option to not suppress null return paths if an argument is null.
Our one basic suppression heuristic is to assume that functions do not
usually return NULL. However, when one of the arguments is NULL it is
suddenly much more likely that NULL is a valid return value. In this case,
we don't suppress the report here, but we do attach /another/ visitor to
go find out if this NULL argument also comes from an inlined function's
error path.

This new behavior, controlled by the 'avoid-suppressing-null-argument-paths'
analyzer-config option, is turned off by default. Turning it on produced
two false positives and no new true positives when running over LLVM/Clang.

This is one of the possible refinements to our suppression heuristics.
<rdar://problem/12350829>

llvm-svn: 166941
2012-10-29 17:31:59 +00:00
Jordan Rose 199fdd825f [analyzer] Use the CallEnter node to get a value for tracked null arguments.
Additionally, don't collect PostStore nodes -- they are often used in
path diagnostics.

Previously, we tried to track null arguments in the same way as any other
null values, but in many cases the necessary nodes had already been
collected (a memory optimization in ExplodedGraph). Now, we fall back to
using the value of the argument at the time of the call, which may not
always match the actual contents of the region, but often will.

This is a precursor to improving our suppression heuristic.
<rdar://problem/12350829>

llvm-svn: 166940
2012-10-29 17:31:53 +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
David Tweed d8bb236e18 Correct test inovocations to use %clang_cc1 rather than direct invocation (so that it can have additional options set when trying to debug issues causing regressions).
llvm-svn: 166681
2012-10-25 13:56:30 +00:00
Jordan Rose 1bbd143945 [analyzer] Handle 'SomeVar.SomeEnumConstant', which is legal in C++.
This caused assertion failures analyzing LLVM.

<rdar://problem/12560282>

llvm-svn: 166529
2012-10-23 23:59:08 +00:00
Jordan Rose 746c06d0bc [analyzer] Replace -analyzer-no-eagerly-trim-egraph with graph-trim-interval.
After every 1000 CFGElements processed, the ExplodedGraph trims out nodes
that satisfy a number of criteria for being "boring" (single predecessor,
single successor, and more). Rather than controlling this with a cc1 option,
which can only disable this behavior, we now have an analyzer-config option,
'graph-trim-interval', which can change this interval from 1000 to something
else. Setting the value to 0 disables reclamation.

The next commit relies on this behavior to actually test anything.

llvm-svn: 166528
2012-10-23 23:59:05 +00:00
Jordan Rose 3957fd5858 [analyzer] Assume 'new' never returns NULL if it could throw an exception.
This is actually required by the C++ standard in
[basic.stc.dynamic.allocation]p3:

  If an allocation function declared with a non-throwing
  exception-specification fails to allocate storage, it shall return a
  null pointer. Any other allocation function that fails to allocate
  storage shall indicate failure only by throwing an exception of a type
  that would match a handler of type std::bad_alloc.

We don't bother checking for the specific exception type, but just go off
the operator new prototype. This should help with a certain class of lazy
initalization false positives.

<rdar://problem/12115221>

llvm-svn: 166363
2012-10-20 02:32:51 +00:00
Andy Gibbs c6e68daac0 Prior to adding the new "expected-no-diagnostics" directive to VerifyDiagnosticConsumer, make the necessary adjustment to 580 test-cases which will henceforth require this new directive.
llvm-svn: 166280
2012-10-19 12:44:48 +00:00
Anna Zaks 92898a79eb [analyzer] Ivar invalidation: identify properties declared in protocols.
llvm-svn: 166211
2012-10-18 19:17:57 +00:00
Jordan Rose 8e785e214b [analyzer] When binding to a ParenExpr, bind to its inner expression instead.
This actually looks through several kinds of expression, such as
OpaqueValueExpr and ExprWithCleanups. The idea is that binding and lookup
should be consistent, and so if the environment needs to be modified later,
the code doing the modification will not have to manually look through these
"transparent" expressions to find the real binding to change.

This is necessary for proper updating of struct rvalues as described in
the previous commit.

llvm-svn: 166121
2012-10-17 19:35:44 +00:00
Jordan Rose 29fc261cd7 [analyzer] Create a temporary region when accessing a struct rvalue.
In C++, rvalues that need to have their address taken (for example, to be
passed to a function by const reference) will be wrapped in a
MaterializeTemporaryExpr, which lets CodeGen know to create a temporary
region to store this value. However, MaterializeTemporaryExprs are /not/
created when a method is called on an rvalue struct, even though the 'this'
pointer needs a valid value. CodeGen works around this by creating a
temporary region anyway; now, so does the analyzer.

The analyzer also does this when accessing a field of a struct rvalue.
This is a little unfortunate, since the rest of the struct will soon be
thrown away, but it does make things consistent with the rest of the
analyzer.

This allows us to bring back the assumption that all known 'this' values
are Locs. This is a revised version of r164828-9, reverted in r164876-7.

<rdar://problem/12137950>

llvm-svn: 166120
2012-10-17 19:35:37 +00:00
Anna Zaks b642fc5db4 [analyzer] Ivar Invalidation: track ivars in continuations and
@implementation.

llvm-svn: 166047
2012-10-16 19:36:37 +00:00
David Blaikie 282ad876bd Implement GCC's -Wint-to-pointer-cast.
This implementation doesn't warn on anything that GCC doesn't warn on with the
exception of templates specializations (GCC doesn't warn, Clang does). The
specific skipped cases (boolean, constant expressions, enums) are open for
debate/adjustment if anyone wants to demonstrate that GCC is being overly
conservative here. The only really obvious false positive I found was in the
Clang regression suite's MPI test - apparently MPI uses specific flag values in
pointer constants. (eg: #define FOO (void*)~0)

llvm-svn: 166039
2012-10-16 18:53:14 +00:00
Jordan Rose 968a1b58fa [analyzer] ObjCContainersASTChecker: minor cleanup and an extra test case.
Follow-up to r165838, which fixed a potential crash.

llvm-svn: 166002
2012-10-16 00:47:25 +00:00
Anna Zaks f4fd1455e0 [analyzer] Do not warn on direct ivar assignments within copy methods.
llvm-svn: 165992
2012-10-15 22:48:14 +00:00
Ted Kremenek c9822ebc97 Remove OSAtomicChecker.
llvm-svn: 165744
2012-10-11 20:58:21 +00:00
Jordan Rose e15fb77df8 Reapply "[analyzer] Treat fields of unions as having symbolic offsets."
This time, actually uncomment the code that's supposed to fix the problem.

This reverts r165671 / 8ceb837585ed973dc36fba8dfc57ef60fc8f2735.

llvm-svn: 165676
2012-10-10 23:23:21 +00:00
Eric Christopher a529f8c9c2 Temporarily Revert "[analyzer] Treat fields of unions as having symbolic offsets."
Author: Jordan Rose <jordan_rose@apple.com>
Date:   Wed Oct 10 21:31:21 2012 +0000

    [analyzer] Treat fields of unions as having symbolic offsets.

    This allows only one field to be active at a time in RegionStore.
    This isn't quite the correct behavior for unions, but it at least
    would handle the case of "value goes in, value comes out" from the
    same field.

    RegionStore currently has a number of places where any access to a union
    results in UnknownVal being returned. However, it is clearly missing
    some cases, or the original issue wouldn't have occurred. It is probably
    now safe to remove those changes, but that's a potentially destabilizing
    change that should wait for more thorough testing.

    Fixes PR14054.

    git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165660 91177308-0d34-0410-b5e6-96231b3b80d8

This reverts commit cf9030e480f77ab349672f00ad302e216c26c92c.

llvm-svn: 165671
2012-10-10 22:49:05 +00:00
Jordan Rose fb29410c85 [analyzer] Treat fields of unions as having symbolic offsets.
This allows only one field to be active at a time in RegionStore.
This isn't quite the correct behavior for unions, but it at least
would handle the case of "value goes in, value comes out" from the
same field.

RegionStore currently has a number of places where any access to a union
results in UnknownVal being returned. However, it is clearly missing
some cases, or the original issue wouldn't have occurred. It is probably
now safe to remove those changes, but that's a potentially destabilizing
change that should wait for more thorough testing.

Fixes PR14054.

llvm-svn: 165660
2012-10-10 21:31:21 +00:00
Jordan Rose d8665b3d1a [analyzer] Don't run non-path-sensitive checks on system headers...
...but do run them on user headers.

Previously, we were inconsistent here: non-path-sensitive checks on code
/bodies/ were only run in the main source file, but checks on
/declarations/ were run in /all/ headers. Neither of those is the
behavior we want.

Thanks to Sujit for pointing this out!

<rdar://problem/12454226>

llvm-svn: 165635
2012-10-10 17:55:40 +00:00
Jordan Rose 69583bfefd [analyzer] Tweak test to run the retain-count checker even on non-Darwin.
This should fix the bots.

llvm-svn: 165358
2012-10-06 02:06:17 +00:00
Jordan Rose adb5354c2c ParentMap: Restore the ability to update an existing map.
The Clang ASTs are a DAG, not a pure tree. However, ParentMap has to
choose a single parent for each object. In the main (only?) cases in
which the AST forms a DAG, it protects from multiple traversal by using
OpaqueValueExprs. Previously, ParentMap would just unconditionally look
through all OpaqueValueExprs when building its map.

In order to make this behavior better for the analyzer's diagnostics,
ParentMap was changed to not set a statement's parent if there already
was one in the map. However, ParentMap is supposed to allow updating
existing mappings by calling addStmt once again. This change makes the
"transparency" of OpaqueValueExprs explicit, and disables it when it
is not desired, rather than checking the current contents of the map.

This new code seems like a big change, but it should actually have
essentially the same performance as before. Only OpaqueValueExprs and
their users (PseudoObjectExpr and BinaryConditionalOperator) will
have any different behavior.

There should be no user-visible functionality change, though a test
has been added for the current behavior of BinaryConditionalOperator
source locations and accompanying Xcode arrows (which are not so great...).

llvm-svn: 165355
2012-10-06 01:19:36 +00:00
Jordan Rose c8a78a37bb [analyzer] Handle implicit statements used for end-of-path nodes' source locs.
Some implicit statements, such as the implicit 'self' inserted for "free"
Objective-C ivar access, have invalid source locations. If one of these
statements is the location where an issue is reported, we'll now look at
the enclosing statements for a valid source location.

<rdar://problem/12446776>

llvm-svn: 165354
2012-10-06 01:19:30 +00:00
Jordan Rose ef77a87a9e Revert "InlineObjCInstanceMethod.m: Remove lines introduced in r165079."
...and fix the run line so that the expected warnings are the same on
all platforms.

This reverts r165088 / d09074f0ca06626914108f1c0d4e70adeb851e01.

llvm-svn: 165124
2012-10-03 16:00:32 +00:00
NAKAMURA Takumi d10e270ae6 InlineObjCInstanceMethod.m: Remove lines introduced in r165079. It broke some builds, on FreeBSD, Linux and Windows.
error: 'warning' diagnostics expected but not seen:
  Line 94: types are incompatible
1 error generated.

llvm-svn: 165088
2012-10-03 02:35:19 +00:00
Jordan Rose 1dd2afd876 [analyzer] Adjust the return type of an inlined devirtualized method call.
In C++, overriding virtual methods are allowed to specify a covariant
return type -- that is, if the return type of the base method is an
object pointer type (or reference type), the overriding method's return
type can be a pointer to a subclass of the original type. The analyzer
was failing to take this into account when devirtualizing a method call,
and anything that relied on the return value having the proper type later
would crash.

In Objective-C, overriding methods are allowed to specify ANY return type,
meaning we can NEVER be sure that devirtualizing will give us a "safe"
return value. Of course, a program that does this will most likely crash
at runtime, but the analyzer at least shouldn't crash.

The solution is to check and see if the function/method being inlined is
the function that static binding would have picked. If not, check that
the return value has the same type. If the types don't match, see if we
can fix it with a derived-to-base cast (the C++ case). If we can't,
return UnknownVal to avoid crashing later.

<rdar://problem/12409977>

llvm-svn: 165079
2012-10-03 01:08:35 +00:00
Ted Kremenek 3c6932922e Tweak AnalyzerOptions::getOptionAsInteger() to populate the string
table, making it printable with the ConfigDump checker.  Along the
way, fix a really serious bug where the value was getting parsed
from the string in code that was in an assert() call.  This means
in a Release-Asserts build this code wouldn't work as expected.

llvm-svn: 165041
2012-10-02 20:31:56 +00:00
Ted Kremenek 5faa5e04a3 Change AnalyzerOptions::mayInlineCXXMemberFunction to default populate
the config string table.  Also setup a test for dumping the analyzer
configuration for C++.

llvm-svn: 165040
2012-10-02 20:31:52 +00:00
Jordan Rose 92375adafb [analyzer] Allow ObjC ivar lvalues where the base is nil.
By analogy with C structs, this seems to be legal, if probably discouraged.
It's only if the ivar is read from or written to that there's a problem.
Running a program that gets the "address" of an instance variable does in
fact return the offset when the base "object" is nil.

This isn't a full revert because r164442 includes some diagnostic tweaks
as well; those have been kept.

This partially reverts r164442 / 08965091770c9b276c238bac2f716eaa4da2dca4.

llvm-svn: 164960
2012-10-01 19:07:22 +00:00
Jordan Rose 28c06b268e [analyzer] Add a test for PR13927 "offsetof replacement flagged as null deref"
This seems to be legal according to C11 6.5.3.2.

No functionality change.

llvm-svn: 164959
2012-10-01 19:07:19 +00:00
Jordan Rose 12024f8776 Revert "[analyzer] Check that a member expr is valid even when the result is an lvalue."
The original intent of this commit was to catch potential null dereferences
early, but it breaks the common "home-grown offsetof" idiom (PR13927):

 (((struct Foo *)0)->member - ((struct foo *)0))

As it turns out, this appears to be legal in C, per a footnote in
C11 6.5.3.2: "Thus, &*E is equivalent to E (even if E is a null pointer)".
In C++ this issue is still open:
  http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#232

We'll just have to make sure we have good path notes in the future.

This reverts r164441 / 9be016dcd1ca3986873a7b66bd4bc027309ceb59.

llvm-svn: 164958
2012-10-01 19:07:15 +00:00
Ted Kremenek 4a5b35eeec Have AnalyzerOptions::getBooleanOption() stick the matching config
string in the config table so that it can be dumped as part of the 
config dumper.  Add a test to show that these options are sticking
and can be cross-checked using FileCheck.

llvm-svn: 164954
2012-10-01 18:28:19 +00:00
Jordan Rose 88dd13fdca Reapply "[analyzer] Handle inlined constructors for rvalue temporaries correctly."
This is related to but not blocked by <rdar://problem/12137950>
("Return-by-value structs do not have associated regions")

This reverts r164875 / 3278d41e17749dbedb204a81ef373499f10251d7.

llvm-svn: 164952
2012-10-01 17:51:35 +00:00
Jordan Rose d60b9168fa Revert "[analyzer] Create a temporary region for rvalue structs when accessing fields"
This reverts commit 6f61df3e7256413dcb99afb9673f4206e3c4992c.

llvm-svn: 164877
2012-09-29 01:36:51 +00:00
Jordan Rose d9b0268401 Revert "[analyzer] Create a temp region when a method is called on a struct rvalue."
This reverts commit 0006ba445962621ed82ec84400a6b978205a3fbc.

llvm-svn: 164876
2012-09-29 01:36:47 +00:00
Jordan Rose cd9000e840 Revert "[analyzer] Handle inlined constructors for rvalue temporaries correctly."
This reverts commit 580cd17f256259f39a382e967173f34d68e73859.

llvm-svn: 164875
2012-09-29 01:36:42 +00:00
Anna Zaks 0353aad5a9 [analyzer] Re-implement IvarInvalidationChecker so that it verifies that
the validation occurred.

The original implementation was pessimistic - we assumed that ivars
which escape are invalidated. This version is optimistic, it assumes
that the ivars will always be explicitly invalidated: either set to nil
or sent an invalidation message.

llvm-svn: 164868
2012-09-29 00:20:38 +00:00
Jordan Rose 19ed6748ea [analyzer] Handle inlined constructors for rvalue temporaries correctly.
Previously the analyzer treated all inlined constructors like lvalues,
setting the value of the CXXConstructExpr to the newly-constructed
region. However, some CXXConstructExprs behave like rvalues -- in
particular, the implicit copy constructor into a pass-by-value argument.
In this case, we want only the /contents/ of a temporary object to be
passed, so that we can use the same "copy each argument into the
parameter region" algorithm that we use for scalar arguments.

This may change when we start modeling destructors of temporaries,
but for now this is the last part of <rdar://problem/12137950>.

llvm-svn: 164830
2012-09-28 17:15:25 +00:00
Jordan Rose b559f18584 [analyzer] Create a temp region when a method is called on a struct rvalue.
An rvalue has no address, but calling a C++ member function requires a
'this' pointer. This commit makes the analyzer create a temporary region
in which to store the struct rvalue and use as a 'this' pointer whenever
a member function is called on an rvalue, which is essentially what
CodeGen does.

More of <rdar://problem/12137950>. The last part is tracking down the
C++ FIXME in array-struct-region.cpp.

llvm-svn: 164829
2012-09-28 17:15:21 +00:00
Jordan Rose e7126582a4 [analyzer] Create a temporary region for rvalue structs when accessing fields
Struct rvalues are represented in the analyzer by CompoundVals,
LazyCompoundVals, or plain ConjuredSymbols -- none of which have associated
regions. If the entire structure is going to persist, this is not a
problem -- either the rvalue will be assigned to an existing region, or
a MaterializeTemporaryExpr will be present to create a temporary region.
However, if we just need a field from the struct, we need to create the
temporary region ourselves.

This is inspired by the way CodeGen handles calls to temporaries;
support for that in the analyzer is coming next.

Part of <rdar://problem/12137950>

llvm-svn: 164828
2012-09-28 17:15:12 +00:00
Anna Zaks 6aef455573 [analyzer] Address Jordan's code review for r164790.
llvm-svn: 164803
2012-09-27 21:57:17 +00:00
Anna Zaks a0c8331663 [analyzer] IvarInvalidation: track synthesized ivars and allow escape
through property getters.

llvm-svn: 164802
2012-09-27 21:57:14 +00:00
Anna Zaks 461f239331 [analyzer] Add an experimental ObjC direct ivar assignment checker.
llvm-svn: 164790
2012-09-27 19:45:15 +00:00
Anna Zaks 8c0dd36ede [analyzer] Address Jordan's code review comments for r164716.
llvm-svn: 164788
2012-09-27 19:45:08 +00:00
Anna Zaks 9802f9fb2a [analyzer] Add experimental ObjC invalidation method checker.
This checker is annotation driven. It checks that the annotated
invalidation method accesses all ivars of the enclosing objects that are
objects of type, which in turn contains an invalidation method.

This is driven by
__attribute((annotation("objc_instance_variable_invalidator")).

llvm-svn: 164716
2012-09-26 18:55:16 +00:00
Anna Zaks a3683dd69e [analyzer] Commit a test case for r164579.
llvm-svn: 164715
2012-09-26 18:55:09 +00:00
Nico Weber c05ecd5b17 Fix two more tests that didn't do anything.
Found with
  find test -type f | xargs grep RUN: | grep '%clang' | grep -iv '%s' | grep -v '%t' | grep -v '\\$'

llvm-svn: 164678
2012-09-26 09:09:17 +00:00
Jordan Rose 902f02db72 [analyzer] Add tests for symbolic expression liveness.
There are very few tests here because SValBuilder is fairly aggressive
about not building SymExprs that we can't evaluate, which saves memory
and CPU but also makes it very much tied to the current constraint
manager. We should probably scale back here and let things decay to
UnknownVal later on.

bitwise-ops.c tests that for the SymExprs we do create, we persist our
assumptions about them. traversal-path-unification.c tests that we do
clean out constraints on arbitrary SymExprs once they have actually died.

llvm-svn: 164623
2012-09-25 19:03:09 +00:00
Jordan Rose db72e2fc37 Reapply "[analyzer] Remove constraints on dead symbols as part of removeDeadBindings."
Previously, we'd just keep constraints around forever, which means we'd
never be able to merge paths that differed only in constraints on dead
symbols.

Because we now allow constraints on symbolic expressions, not just single
symbols, this requires changing SymExpr::symbol_iterator to include
intermediate symbol nodes in its traversal, not just the SymbolData leaf
nodes.

This depends on the previous commit to be correct. Originally applied in
r163444, reverted in r164275, now being re-applied.

llvm-svn: 164622
2012-09-25 19:03:06 +00:00
Anna Zaks b9828203df [analyzer] Really turn on dynamic-bifurcation on by default.
Thanks to Byoungyoung for realizing taht we are not passing the default
option correctly.

llvm-svn: 164543
2012-09-24 17:43:47 +00:00
Jordan Rose 52de8eec01 [analyzer] Suppress bugs whose paths go through the return of a null pointer.
This is a heuristic intended to greatly reduce the number of false
positives resulting from inlining, particularly inlining of generic,
defensive C++ methods that live in header files. The suppression is
triggered in the cases where we ask to track where a null pointer came
from, and it turns out that the source of the null pointer was an inlined
function call.

This change brings the number of bug reports in LLVM from ~1500 down to
around ~300, a much more manageable number. Yes, some true positives may
be hidden as well, but from what I looked at the vast majority of silenced
reports are false positives, and many of the true issues found by the
analyzer are still reported.

I'm hoping to improve this heuristic further by adding some exceptions
next week (cases in which a bug should still be reported).

llvm-svn: 164449
2012-09-22 01:25:06 +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
Jordan Rose 6f3d2f0acd [analyzer] Look through OpaqueValueExprs when tracking a nil value.
This allows us to show /why/ a particular object is nil, even when it is
wrapped in an OpaqueValueExpr.

llvm-svn: 164445
2012-09-22 01:24:49 +00:00
Jordan Rose 106b037a85 [analyzer] Better path notes for null pointers passed as arguments.
Rather than saying "Null pointer value stored to 'foo'", we now say
"Passing null pointer value via Nth parameter 'foo'", which is much better.
The note is also now on the argument expression as well, rather than the
entire call.

This paves the way for continuing to track arguments back to their sources.

<rdar://problem/12211490>

llvm-svn: 164444
2012-09-22 01:24:46 +00:00
Jordan Rose 1d64a49855 [analyzer] Check that an ObjCIvarRefExpr's base is non-null even as an lvalue.
Like with struct fields, we want to catch cases like this early,
so that we can produce better diagnostics and path notes:

  PointObj *p = nil;
  int *px = &p->_x; // should warn here
  *px = 1;

llvm-svn: 164442
2012-09-22 01:24:38 +00:00
Jordan Rose 04dcb7235f [analyzer] Check that a member expr is valid even when the result is an lvalue.
We want to catch cases like this early, so that we can produce better
diagnostics and path notes:

  Point *p = 0;
  int *px = &p->x; // should warn here
  *px = 1;

llvm-svn: 164441
2012-09-22 01:24:33 +00:00
Ted Kremenek d81a4a18b4 Add faux-body support for dispatch_once().
llvm-svn: 164348
2012-09-21 00:52:24 +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
Fariborz Jahanian 2f4e33aba2 Improvements to my patch in r164143 per
Richard's comments. // rdar://12202422

llvm-svn: 164316
2012-09-20 19:36:41 +00:00
NAKAMURA Takumi 77369457e0 clang/test/Analysis: Fix the declaration of strlen() for 32 bit targets.
- Inputs/system-header-simulator.h: Declare strlen() with size_t.

  - malloc-interprocedural.c: Move the definition of size_t into the header above.

Then XFAIL can be pruned.

llvm-svn: 164300
2012-09-20 11:03:56 +00:00
NAKAMURA Takumi 4aa6a010d2 test/Analysis/malloc-interprocedural.c: Mark it as XFAIL: cygwin,mingw,msvc for now. Investigating.
llvm-svn: 164295
2012-09-20 08:44:12 +00:00
Jordan Rose d6e5fd52f0 [analyzer] MallocChecker should not do post-call checks on inlined functions.
If someone provides their own function called 'strdup', or 'reallocf', or
even 'malloc', and we inlined it, the inlining should have given us all the
malloc-related information we need. If we then try to attach new information
to the return value, we could end up with spurious warnings.

<rdar://problem/12317671>

llvm-svn: 164276
2012-09-20 01:55:32 +00:00
Jordan Rose ae134c6449 Revert "[analyzer] Remove constraints on dead symbols as part of removeDeadBindings."
While we definitely want this optimization in the future, we're not
currently handling constraints on symbolic /expressions/ correctly.
These should stay live even if the SymExpr itself is no longer referenced
because could recreate an identical SymExpr later. Only once the SymExpr
can no longer be recreated -- i.e. a component symbol is dead -- can we
safely remove the constraints on it.

This liveness issue is tracked by <rdar://problem/12333297>.

This reverts r163444 / 24c7f98828e039005cff3bd847e7ab404a6a09f8.

llvm-svn: 164275
2012-09-20 01:54:56 +00:00
Fariborz Jahanian b1885425c4 c: warn when an integer value comparison with an
integral expression have the obvious result.
Patch reviewed by John McCall off line.
// rdar://12202422

llvm-svn: 164143
2012-09-18 17:37:21 +00:00
Anna Zaks 4278234360 [analyzer] Teach the analyzer about implicit initialization of statics
in ObjCMethods.

Extend FunctionTextRegion to represent ObjC methods as well as
functions. Note, it is not clear what type ObjCMethod region should
return. Since the type of the FunctionText region is not currently used,
defer solving this issue.

llvm-svn: 164046
2012-09-17 19:13:56 +00:00
Ted Kremenek e5c0a9bad4 When warning about unsafe uses of dispatch_once, specially handle the
crazy case where dispatch_once gets redefined as a macro that calls
_dispatch_once (which calls the real dispatch_once).  Users want to
see the warning in their own code.

Fixes <rdar://problem/11617767>

llvm-svn: 163816
2012-09-13 18:18:37 +00:00
Anna Zaks 5d2964e770 [analyzer] Do not report use of undef on "return foo();" when the return type is void.
Fixes a false positive found by analyzing LLVM code base.

llvm-svn: 163750
2012-09-12 22:57:40 +00:00
Anna Zaks 75cfbb60a8 [analyzer] Fix another false positive in malloc realloc logic.
llvm-svn: 163749
2012-09-12 22:57:34 +00:00
Anna Zaks e663b80975 [analyzer] Teach UndefOrNullArgVisitor to track parent regions.
llvm-svn: 163748
2012-09-12 22:57:30 +00:00
Jordan Rose 2010d437f9 [analyzer] Re-add reinterpret_cast virtual call test case from r163644.
We mostly just don't want to crash analyzing this test case; it's likely
the code found here will actually crash if compiled and run.

llvm-svn: 163746
2012-09-12 21:50:56 +00:00
Jordan Rose 99c6c2b4e2 Revert "[analyzer] Use the static type for a virtual call if the dynamic type is worse."
Using the static type may be inconsistent with later calls. We should just
report that there is no inlining definition available if the static type is
better than the dynamic type. See next commit.

This reverts r163644 / 19d5886d1704e24282c86217b09d5c6d35ba604d.

llvm-svn: 163744
2012-09-12 21:48:13 +00:00
NAKAMURA Takumi fcd16e36c8 clang/test: [PR8833] Introduce the feature "LP64" to suppress LLP64-incompatible tests.
I think some of them could be rewritten to fit also LLP64.

llvm-svn: 163699
2012-09-12 10:45:40 +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
Chandler Carruth 66a34a6a45 Adjust some analyzer tests to place widely shared inputs inside of an
'Inputs' subdirectory.

The general desire has been to have essentially all of the non-test
input files live in such directories, with some exceptions for obvious
and common patterns like 'foo.c' using 'foo.h'.

This came up because our distributed test runner couldn't find some of
the headers, for example with stl.cpp.

No functionality changed, just shuffling around here.

llvm-svn: 163674
2012-09-12 01:11:10 +00:00
Chandler Carruth 575037f0de Fix up more "$t"s in this test that should be "%t"s.
llvm-svn: 163673
2012-09-12 01:11:05 +00:00
Jordan Rose e35fdeb330 [analyzer] Use the static type for a virtual call if the dynamic type is worse.
reinterpret_cast does not provide any of the usual type information that
static_cast or dynamic_cast provide -- only the new type. This can get us
in a situation where the dynamic type info for an object is actually a
superclass of the static type, which does not match what CodeGen does at all.
In these cases, just fall back to the static type as the best possible type
for devirtualization.

Should fix the crashes on our internal buildbot.

llvm-svn: 163644
2012-09-11 18:47:13 +00:00
Jordan Rose 12f669e3cd [analyzer] Member function calls that use qualified names are non-virtual.
C++11 [expr.call]p1: ...If the selected function is non-virtual, or if the
  id-expression in the class member access expression is a qualified-id,
  that function is called. Otherwise, its final overrider in the dynamic type
  of the object expression is called.

<rdar://problem/12255556>

llvm-svn: 163577
2012-09-11 00:31:02 +00:00
Anna Zaks 1ded453e36 [analyzer] Turn stl inlining back on.
The one reported bug, which was exposed by stl inlining, is addressed in
r163558.

llvm-svn: 163574
2012-09-10 23:59:02 +00:00
Anna Zaks 4f9c460874 [analyzer] Do not count calls to small functions when computing stack
depth.

We only want to count how many substantial functions we inlined. This
is an improvement to r163558.

llvm-svn: 163571
2012-09-10 23:35:11 +00:00
Anna Zaks 5446f4dfb1 [analyzer] Add an option to enable/disable objc inlining.
llvm-svn: 163562
2012-09-10 22:56:41 +00:00
Anna Zaks 14ce52492f [analyzer] Add ipa-always-inline-size option (with 3 as the default).
The option allows to always inline very small functions, whose size (in
number of basic blocks) is set using -analyzer-config
ipa-always-inline-size option.

llvm-svn: 163558
2012-09-10 22:37:19 +00:00
Jordan Rose 1e0e4001c8 [analyzer] For now, don't inline C++ standard library functions.
This is a (heavy-handed) solution to PR13724 -- until we know we can do
a good job inlining the STL, it's best to be consistent and not generate
more false positives than we did before. We can selectively whitelist
certain parts of the 'std' namespace that are known to be safe.

This is controlled by analyzer config option 'c++-stdlib-inlining', which
can be set to "true" or "false".

This commit also adds control for whether or not to inline any templated
functions (member or non-member), under the config option
'c++-template-inlining'. This option is currently on by default.

llvm-svn: 163548
2012-09-10 21:27:35 +00:00
Ted Kremenek 83e480f50f Now that I have a test file to work with, disable the Filecheck part of this test.
llvm-svn: 163536
2012-09-10 19:50:17 +00:00
Ted Kremenek a8755da8b3 Correctly 'cat' out test files.
llvm-svn: 163534
2012-09-10 19:13:08 +00:00
Ted Kremenek fc57cdf5b8 As a debugging aid to unbreak the buildbots, cat the plist files so I can view them on different builders.
llvm-svn: 163529
2012-09-10 18:38:43 +00:00
Ted Kremenek e46c74f3ec Re-enable FileCheck testing of retain-release.m test, and force
a C++ dialect.  Let's see if this is the portability issue with this test.

llvm-svn: 163524
2012-09-10 17:35:24 +00:00
Ted Kremenek 1f9e7f4f91 Temporarily disable FileCheck part of this test.
llvm-svn: 163515
2012-09-10 15:16:32 +00:00
Ted Kremenek 6c7a5eae6d Revert "Revert Ted's r163489 and r163490, due to breakage."
I need to see how this breaks on other platforms when I fix the issue
that Benjamin Kramer pointed out.

This includes r163489 and r163490, plus a two line change.

llvm-svn: 163512
2012-09-10 14:50:55 +00:00
NAKAMURA Takumi 6eb1399088 Revert Ted's r163489 and r163490, due to breakage.
r163489, "Take another crack at stabilizing the emission order of analyzer"
r163490, "Use isBeforeInTranslationUnitThan() instead of operator<."

llvm-svn: 163497
2012-09-10 09:17:27 +00:00
Ted Kremenek 3d92699d3c Take another crack at stabilizing the emission order of analyzer
diagnostics without using FoldingSetNodeIDs.  This is done
by doing a complete recursive comparison of the PathDiagnostics.

Note that the previous method of comparing FoldingSetNodeIDs did
not end up relying on unstable things such as pointer addresses, so
I suspect this may still have some issues on various buildbots because
I'm not sure if the true source of non-determinism has been eliminated.
The tests pass for me, so the only way to know is to commit this change
and see what happens.

llvm-svn: 163489
2012-09-10 06:20:06 +00:00
Ted Kremenek 6ed296661a Try disabling the FileCheck part of the retain-release.m test to see if it fixes the buildbots.
llvm-svn: 163462
2012-09-08 07:40:15 +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 b724ea5c2e This test does not require --exact-match from FileCheck.
llvm-svn: 163456
2012-09-08 04:29:08 +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
Jordan Rose 5481cfefa6 [analyzer] ObjCSelfInitChecker should always clean up in postCall checks.
ObjCSelfInitChecker stashes information in the GDM to persist it across
function calls; it is stored in pre-call checks and retrieved post-call.
The post-call check is supposed to clear out the stored state, but was
failing to do so in cases where the call did not have a symbolic return
value.

This was actually causing the inappropriate cache-out from r163361.
Per discussion with Anna, we should never actually cache out when
assuming the receiver of an Objective-C message is non-nil, because
we guarded that node generation by checking that the state has changed.
Therefore, the only states that could reach this exact ExplodedNode are
ones that should have merged /before/ making this assumption.

r163361 has been reverted and the test case removed, since it won't
actually test anything interesting now.

llvm-svn: 163449
2012-09-08 01:47:28 +00:00
Ted Kremenek a9f89b1c31 Revert "Add plist output for retain-release.m in addition to -verify checking."
llvm-svn: 163447
2012-09-08 01:25:02 +00:00
Ted Kremenek 1fdcfcdf13 Revert "Attempt to make the PathDiagnostic emission order more deterministic by"
llvm-svn: 163446
2012-09-08 01:25:00 +00:00
Jordan Rose 5860e329a4 [analyzer] Remove constraints on dead symbols as part of removeDeadBindings.
Previously, we'd just keep constraints around forever, which means we'd
never be able to merge paths that differed only in constraints on dead
symbols.

Because we now allow constraints on symbolic expressions, not just single
symbols, this requires changing SymExpr::symbol_iterator to include
intermediate symbol nodes in its traversal, not just the SymbolData leaf
nodes.

llvm-svn: 163444
2012-09-08 01:24:53 +00:00
Jordan Rose aaf8318480 [analyzer] Cast the result of a placement new-expression to the correct type.
This is necessary because further analysis will assume that the SVal's
type matches the AST type. This caused a crash when trying to perform
a derived-to-base cast on a C++ object that had been new'd to be another
object type.

Yet another crash in PR13763.

llvm-svn: 163442
2012-09-08 01:24:38 +00:00
Anna Zaks 044f3e2694 [analyzer] Address John's code review for r163407.
Teach malloc sizeof checker to find type inconsistencies in multi-
dimensional arrays.

llvm-svn: 163438
2012-09-08 00:09:02 +00:00
Ted Kremenek 334ad6ac13 Attempt to make the PathDiagnostic emission order more deterministic by
looking at PathPieces.

llvm-svn: 163427
2012-09-07 22:24:24 +00:00
Ted Kremenek 9df430c46d Add plist output for retain-release.m in addition to -verify checking.
llvm-svn: 163418
2012-09-07 20:31:32 +00:00
Anna Zaks 694be01519 [analyzer] Fix a false positive in sizeof malloc checker.
Don't warn when the sizeof argument is an array with the same element
type as the pointee of the return type.

llvm-svn: 163407
2012-09-07 19:20:13 +00:00
Ted Kremenek a8d0ca070f Add test case for <rdar://problem/12075238>, which recently got fixed by changes to RegionStore.
llvm-svn: 163406
2012-09-07 19:09:51 +00:00
Ted Kremenek b2f6e69af9 Revert "Rework the retain-release.m test to use FileCheck and the "text" output"
Apparently the output of this test is not deterministic.  Needs investigation.

llvm-svn: 163377
2012-09-07 07:40:40 +00:00
Ted Kremenek 3f58774c8d Fix off-by-one bug in diagnostic prose of ObjCContainersASTChecker.
While the check itself should count 0-based for the parameter index,
the diagnostic should be 1-based (first, second, third, not start at 0).

Fixes <rdar://problem/12249569>.

llvm-svn: 163375
2012-09-07 07:13:08 +00:00
Ted Kremenek 74eb55a23d Rework the retain-release.m test to use FileCheck and the "text" output
of the analyzer, as the RetainReleaseChecker has many fine-grain
path diagnostic events that were not being checked.  This uncovered
an inconsistency between the path diagnostics between Objective-C
and Objective-C++ code in ConditionBRVisitor that was fixed in a recent
patch.

llvm-svn: 163373
2012-09-07 06:51:47 +00:00
Ted Kremenek 7c15040e98 Fix bug in ConditionBRVisitor where for C++ (and not C) we were not ignoring
implicit pointer-to-boolean conversions in condition expressions.  This would
result in inconsistent diagnostic emission between C and C++.

A consequence of this is now ConditionBRVisitor and TrackConstraintBRVisitor may
emit redundant diagnostics, for example:

  "Assuming pointer value is null" (TrackConstraintBRVisitor)
  "Assuming 'p' is null" (ConditionBRVisitor)

We need to reconcile the two, and perhaps prefer one over the other in some
cases.

llvm-svn: 163372
2012-09-07 06:51:37 +00:00
Jordan Rose 81456d9f6d [analyzer] Fail gracefully when the dynamic type is outside the hierarchy.
With some particularly evil casts, we can get an object whose dynamic type
is not actually a subclass of its static type. In this case, we won't even
find the statically-resolved method as a devirtualization candidate.

Rather than assert that this situation cannot occur, we now simply check
that the dynamic type is not an ancestor or descendent of the static type,
and leave it at that.

This error actually occurred analyzing LLVM: CallEventManager uses a
BumpPtrAllocator to allocate a concrete subclass of CallEvent
(FunctionCall), but then casts it to the actual subclass requested
(such as ObjCMethodCall) to perform the constructor.

Yet another crash in PR13763.

llvm-svn: 163367
2012-09-07 01:19:42 +00:00
Ted Kremenek c008db99d7 Teach RetainCountChecker that CFPlugInInstanceCreate does not
return a CF object at all.

Fixes <rdar://problem/9566345>

llvm-svn: 163362
2012-09-06 23:47:02 +00:00
Jordan Rose 7e97996f4e [analyzer] Don't crash if we cache out while evaluating an ObjC message.
A bizarre series of coincidences led us to generate a previously-seen
node in the middle of processing an Objective-C message, where we assume
the receiver is non-nil. We were assuming that such an assumption would
never "cache out" like this, and blithely went on using a null ExplodedNode
as the predecessor for the next step in evaluation.

Although the test case committed here is complicated, this could in theory
happen in other ways as well, so the correct fix is just to test if the
non-nil assumption results in an ExplodedNode we've seen before.

<rdar://problem/12243648>

llvm-svn: 163361
2012-09-06 23:44:36 +00:00
Ted Kremenek 2a786959b1 Refine diagnostics for leaks reported when returning an object
via function/method with [CF,NS]_RETURNS_NOT_RETAINED.

Fixes <rdar://problem/11379000>.

llvm-svn: 163355
2012-09-06 23:03:07 +00:00
Ted Kremenek cadd9f186a Tweak DeadStoresChecker to not warn about dead stores to variables that
are used in EH code.  Right now the CFG doesn't support exceptions well,
so we need this hack to avoid bogus dead store warnings.

Fixes <rdar://problem/12147586>

llvm-svn: 163353
2012-09-06 22:32:48 +00:00
Jordan Rose 2bc9674b0a [analyzer] Don't attempt to devirtualize calls to base class destructors.
CXXDestructorCall now has a flag for when it is a base destructor call.
Other kinds of destructor calls (locals, fields, temporaries, and 'delete')
all behave as "whole-object" destructors and do not behave differently
from one another (specifically, in these cases we /should/ try to
devirtualize a call to a virtual destructor).

This was causing crashes in both our internal buildbot, the crash still
being tracked in PR13765, and some of the crashes being tracked in PR13763,
due to a assertion failure. (The behavior under -Asserts happened to be
correct anyway.)

Adding this knowledge also allows our DynamicTypePropagation checker to do
a bit less work; the special rules about virtual method calls during a
destructor only require extra handling during base destructors.

llvm-svn: 163348
2012-09-06 20:37:08 +00:00
Anna Zaks 3245e584db [analyzer] Enhance the member expr tracking to account for references.
As per Jordan's suggestion. (Came out of code review for r163261.)

llvm-svn: 163269
2012-09-05 23:41:54 +00:00
Jordan Rose 6d671cc34a [analyzer] Always include destructors in the analysis CFG.
While destructors will continue to not be inlined (unless the analyzer
config option 'c++-inlining' is set to 'destructors'), leaving them out
of the CFG is an incomplete model of the behavior of an object, and
can cause false positive warnings (like PR13751, now working).

Destructors for temporaries are still not on by default, since
(a) we haven't actually checked this code to be sure it's fully correct
    (in particular, we probably need to be very careful with regard to
    lifetime-extension when a temporary is bound to a reference,
    C++11 [class.temporary]p5), and
(b) ExprEngine doesn't actually do anything when it sees a temporary
    destructor in the CFG -- not even invalidate the object region.

To enable temporary destructors, set the 'cfg-temporary-dtors' analyzer
config option to '1'. The old -cfg-add-implicit-dtors cc1 option, which
controlled all implicit destructors, has been removed.

llvm-svn: 163264
2012-09-05 22:55:23 +00:00
Anna Zaks e5cb4981d0 [analyzer] Fix a crash PR13762.
llvm-svn: 163262
2012-09-05 22:31:58 +00:00
Anna Zaks b4b2b57ee0 [analyzer] NullOrUndef diagnostics: track symbols binded to regions.
If a region is binded to a symbolic value, we should track the symbol.

(The code I changed was not previously exercised by the regression
tests.)

llvm-svn: 163261
2012-09-05 22:31:55 +00:00
Jordan Rose 6d92188ff7 [analyzer] Fix bad test from r163220.
Add a FIXME to the test while I track down the real problem.

llvm-svn: 163222
2012-09-05 17:34:50 +00:00
Jordan Rose fcdda36149 [analyzer] Be more forgiving about calling methods on struct rvalues.
The problem is that the value of 'this' in a C++ member function call
should always be a region (or NULL). However, if the object is an rvalue,
it has no associated region (only a conjured symbol or LazyCompoundVal).
For now, we handle this in two ways:

1) Actually respect MaterializeTemporaryExpr. Before, it was relying on
   CXXConstructExpr to create temporary regions for all struct values.
   Now it just does the right thing: if the value is not in a temporary
   region, create one.

2) Have CallEvent recognize the case where its 'this' pointer is a
   non-region, and just return UnknownVal to keep from confusing clients.

The long-term problem is being tracked internally in <rdar://problem/12137950>,
but this makes many test cases pass.

llvm-svn: 163220
2012-09-05 17:11:26 +00:00
Jordan Rose bc009d4493 Revert "[analyzer] Treat all struct values as regions (even rvalues)."
This turned out to have many implications, but what eventually seemed to
make it unworkable was the fact that we can get struct values (as
LazyCompoundVals) from other places besides return-by-value function calls;
that is, we weren't actually able to "treat all struct values as regions"
consistently across the entire analyzer core.

Hopefully we'll be able to come up with an alternate solution soon.

This reverts r163066 / 02df4f0aef142f00d4637cd851e54da2a123ca8e.

llvm-svn: 163218
2012-09-05 17:11:15 +00:00
Jordan Rose 7523d1a847 [analyzer] Don't use makeIntVal to create a floating-point value.
SimpleSValBuilder processes a couple trivial identities, including 'x - x'
and 'x ^ x' (both 0). However, the former could appear with arguments of
floating-point type, and we weren't checking for that. This started
triggering an assert with r163069, which checks that a constant value is
actually going to be used as an integer or pointer.

llvm-svn: 163159
2012-09-04 19:34:58 +00:00
Jordan Rose 82ae9898ef [analyzer] Treat all struct values as regions (even rvalues).
This allows us to correctly symbolicate the fields of structs returned by
value, as well as get the proper 'this' value for when methods are called
on structs returned by value.

This does require a moderately ugly hack in the StoreManager: if we assign
a "struct value" to a struct region, that now appears as a Loc value being
bound to a region of struct type. We handle this by simply "dereferencing"
the struct value region, which should create a LazyCompoundVal.

This should fix recent crashes analyzing LLVM and on our internal buildbot.

<rdar://problem/12137950>

llvm-svn: 163066
2012-09-01 17:39:09 +00:00
Jordan Rose 2da564380a [analyzer] Always derive a CallEvent's return type from its origin expr.
Previously, we preferred to get a result type by looking at the callee's
declared result type. This allowed us to handlereferences, which are
represented in the AST as lvalues of their pointee type. (That is, a call
to a function returning 'int &' has type 'int' and value kind 'lvalue'.)

However, this results in us preferring the original type of a function
over a casted type. This is a problem when a function  pointer is casted
to another type, because the conjured result value will have the wrong
type. AdjustedReturnValueChecker is supposed to handle this, but still
doesn't handle the case where there is no "original function" at all,
i.e. where the callee is unknown.

Now, we instead look at the call expression's value kind (lvalue, xvalue,
or prvalue), and adjust the expr's type accordingly. This will have no
effect when the function is inlined, and will conjure the value that will
actually be used when it is not.

This makes AdjustedReturnValueChecker /nearly/ unnecessary; unfortunately,
the cases where it would still be useful are where we need to cast the
result of an inlined function or a checker-evaluated function, and in these
cases we don't know what we're casting /from/ by the time we can do post-
call checks. In light of that, remove AdjustedReturnValueChecker, which
was already not checking quite a few calls.

llvm-svn: 163065
2012-09-01 17:39:00 +00:00
Jordan Rose d65f1c8d6e [analyzer] RetainCountChecker: don't assume all functions have names.
Fixes a hard-to-reach crash when calling a non-member overloaded operator
with arguments that may be callbacks.

Future-proofing: don't make the same assumption in MallocSizeofChecker.
Aside from possibly respecting attributes in the future, it might be
possible to call 'malloc' through a function pointer.

I audited all other uses of FunctionDecl::getIdentifier() in the analyzer;
they all now correctly test to see if the identifier is present before
using it.

llvm-svn: 163012
2012-08-31 18:19:18 +00:00
Jordan Rose 219c9d0dd3 [analyzer] Though C++ inlining is enabled, don't inline ctors and dtors.
More generally, this adds a new configuration option 'c++-inlining', which
controls which C++ member functions can be considered for inlining. This
uses the new -analyzer-config table, so the cc1 arguments will look like this:

... -analyzer-config c++-inlining=[none|methods|constructors|destructors]

Note that each mode implies that all the previous member function kinds
will be inlined as well; it doesn't make sense to inline destructors
without inlining constructors, for example.

The default mode is 'methods'.

llvm-svn: 163004
2012-08-31 17:06:49 +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 e9b0231152 [analyzer] Make analyzer-ipa=dynamic-bifurcate the default.
There are two tests regressions that come from the fact that the Retain
Count checker does not cancel out inlining of ObjC methods.

llvm-svn: 162950
2012-08-30 22:42:59 +00:00
Anna Zaks b504f44d60 [analyzer] Fixup for r162935 as per Jordan's review.
Thanks for catching this!

llvm-svn: 162949
2012-08-30 22:42:41 +00:00
Anna Zaks 4818bbe348 [analyzer] Do not propagate the [super init] could be nil assumption
from callee to caller.

radar://12109638

llvm-svn: 162935
2012-08-30 19:40:52 +00:00
Ted Kremenek 401ce8edba Teach RetainCountChecker about 'pragma clang arc_cf_code_audited'.
llvm-svn: 162934
2012-08-30 19:27:02 +00:00
Anna Zaks 256127388a [analyzer] Stop tracking symbols based on a retain count summary of
inlined function.

This resolves retain count checker false positives that are caused by
inlining ObjC and other methods. Essentially, if we are passing an
object to a method with "delegate" in the selector or a function pointer
as another argument, we should stop tracking the other parameters/return
value as far as the retain count checker is concerned.

llvm-svn: 162876
2012-08-29 23:23:43 +00:00
Anna Zaks 07a821fb17 [analyzer] Fixup 162863.
Thanks Jordan.

llvm-svn: 162875
2012-08-29 23:23:39 +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
Jordan Rose 2c625dd6f9 [analyzer] C++ objects returned on the stack may be wrapped in ExprWithCleanups.
In C++, objects being returned on the stack are actually copy-constructed into
the return value. That means that when a temporary is returned, it still has
to be destroyed, i.e. the returned expression will be wrapped in an
ExprWithCleanups node. Our "returning stack memory" checker needs to look
through this node to see if we really are returning an object by value.

PR13722

llvm-svn: 162817
2012-08-29 01:11:59 +00:00
Jordan Rose 8d48938bf3 [analyzer] Teach CallEventManager that CXXTemporaryObjectExpr is also a ctor.
Specifically, CallEventManager::getCaller was looking at the call site for
an inlined call and trying to see what kind of call it was, but it only
checked for CXXConstructExprClass. (It's not using an isa<> here to avoid
doing three more checks on the the statement class.)

This caused an unreachable when we actually did inline the constructor of a
temporary object.

PR13717

llvm-svn: 162792
2012-08-28 20:52:21 +00:00
Jordan Rose 2be6e30d96 [analyzer] When we look for the last stmt in a function, skip implicit dtors.
When exiting a function, the analyzer looks for the last statement in the
function to see if it's a return statement (and thus bind the return value).
However, the search for "the last statement" was accepting statements that
were in implicitly-generated inlined functions (i.e. destructors). So we'd
go and get the statement from the destructor, and then say "oh look, this
function had no explicit return...guess there's no return value". And /that/
led to the value being returned being declared dead, and all our leak
checkers complaining.

llvm-svn: 162791
2012-08-28 20:52:13 +00:00
Jordan Rose 5090904d6c [analyzer] If the last store into a region came from a function, step into it.
Previously, if we were tracking stores to a variable 'x', and came across this:

x = foo();

...we would simply emit a note here and stop. Now, we'll step into 'foo' and
continue tracking the returned value from there.

<rdar://problem/12114689>

llvm-svn: 162718
2012-08-28 00:50:42 +00:00
Jordan Rose 1a61674f5a [analyzer] Look through casts when trying to track a null pointer dereference.
Also, add comments to addTrackNullOrUndefValueVisitor.

Thanks for the review, Anna!

llvm-svn: 162695
2012-08-27 20:18:30 +00:00
Jordan Rose 561919e5bd [analyzer] Don't inline constructors for objects allocated with operator new.
Because the CXXNewExpr appears after the CXXConstructExpr in the CFG, we don't
actually have the correct region to construct into at the time we decide
whether or not to inline. The long-term fix (discussed in PR12014) might be to
introduce a new CFG node (CFGAllocator) that appears before the constructor.

Tracking the short-term fix in <rdar://problem/12180598>.

llvm-svn: 162689
2012-08-27 18:39:22 +00:00
Jordan Rose c93183042f [analyzer] Inline constructors for any object with a trivial destructor.
This allows us to better reason about status objects, like Clang's own
llvm::Optional (when its contents are trivially destructible), which are
often intended to be passed around by value.

We still don't inline constructors for temporaries in the general case.

<rdar://problem/11986434>

llvm-svn: 162681
2012-08-27 17:50:07 +00:00
Jordan Rose 0a0aa84da3 [analyzer] Use the common evalBind infrastructure for initializers.
This allows checkers (like the MallocChecker) to process the effects of the
bind. Previously, using a memory-allocating function (like strdup()) in an
initializer would result in a leak warning.

This does bend the expectations of checkBind a bit; since there is no
assignment expression, the statement being used is the initializer value.
In most cases this shouldn't matter because we'll use a PostInitializer
program point (rather than PostStmt) for any checker-generated nodes, though
we /will/ generate a PostStore node referencing the internal statement.
(In theory this could have funny effects if someone actually does an
assignment within an initializer; in practice, that seems like it would be
very rare.)

<rdar://problem/12171711>

llvm-svn: 162637
2012-08-25 01:06:23 +00:00
Ted Kremenek 722398f1d4 Fix analyzer tests.
llvm-svn: 162588
2012-08-24 20:39:55 +00:00
Jordan Rose 51c27163c0 [analyzer] If we dereference a NULL that came from a function, show the return.
More generally, any time we try to track where a null value came from, we
should show if it came from a function. This usually isn't necessary if
the value is symbolic, but if the value is just a constant we previously
just ignored its origin entirely. Now, we'll step into the function and
recursively add a visitor to the returned expression.

<rdar://problem/12114609>

llvm-svn: 162563
2012-08-24 16:34:31 +00:00
Anna Zaks fe6eb67b12 [analyzer] Fix realloc related bug in the malloc checker.
When reallocation of a non-allocated (not owned) symbol fails do not
expect it to be freed.

llvm-svn: 162533
2012-08-24 02:28:20 +00:00
Anna Zaks 3d5d3d3e2c [analyzer] Make analyzer less aggressive when dealing with [self init].
With inlining, retain count checker starts tracking 'self' through the
init methods. The analyser results were too noisy if the developer
did not follow 'self = [super init]' pattern (which is common
especially in older code bases) - we reported self init anti-pattern AND
possible use-after-free. This patch teaches the retain count
checker to assume that [super init] does not fail when it's not consumed
by another expression. This silences the retain count warning that warns
about possibility of use-after-free when init fails, while preserving
all the other checking on 'self'.

llvm-svn: 162508
2012-08-24 00:06:12 +00:00
Jordan Rose 434f132060 [analyzer] For now, treat pointers-to-members as non-null void * symbols.
Until we have full support for pointers-to-members, we can at least
approximate some of their use by tracking null and non-null values.
We thus treat &A::m_ptr as a non-null void * symbol, and MemberPointer(0)
as a pointer-sized null constant.

This enables support for what is sometimes called the "safe bool" idiom,
demonstrated in the test case.

llvm-svn: 162495
2012-08-23 23:01:43 +00:00
Jordan Rose 081af085eb [analyzer] Handle UserDefinedConversion casts in C++.
This is trivial; the UserDefinedConversion always wraps a CXXMemberCallExpr
for the appropriate conversion function, so it's just a matter of
propagating that value to the CastExpr itself.

llvm-svn: 162494
2012-08-23 23:01:39 +00:00
Jordan Rose e5d5393efc [analyzer] Support C++ default arguments if they are literal values.
A CXXDefaultArgExpr wraps an Expr owned by a ParmVarDecl belonging to the
called function. In general, ExprEngine and Environment ought to treat this
like a ParenExpr or other transparent wrapper expression, with the inside
expression evaluated first.

However, if we call the same function twice, we'd produce a CFG that contains
the same wrapped expression twice, and we're not set up to handle that. I've
added a FIXME to the CFG builder to come back to that, but meanwhile we can
at least handle expressions that don't need to be explicitly evaluated:
literals. This probably handles many common uses of default parameters:
true/false, null, etc.

Part of PR13385 / <rdar://problem/12156507>

llvm-svn: 162453
2012-08-23 18:10:53 +00:00
Anna Zaks 5a5a1755f2 [analyzer] Add osx.cocoa.NonNilReturnValue checker.
The checker adds assumptions that the return values from the known APIs
are non-nil. Teach the checker about NSArray/NSMutableArray/NSOrderedSet
objectAtIndex, objectAtIndexedSubscript.

llvm-svn: 162398
2012-08-22 21:19:56 +00:00
Ted Kremenek 326702f1a1 Despite me asking Jordan to do r162313, revert it. We can provide
another way to whitelist these special cases.  This is an intermediate patch.

llvm-svn: 162386
2012-08-22 19:58:20 +00:00
Ted Kremenek a056d62961 Remove BasicConstraintManager. It hasn't been in active service for a while.
As part of this change, I discovered that a few of our tests were not testing
the RangeConstraintManager.  Luckily all of those passed when I moved them
over to use that constraint manager.

llvm-svn: 162384
2012-08-22 19:47:13 +00:00
Jordan Rose 4d9fbd7ec4 [analyzer] -analyzer-ipa=inlining is now the default. Remove it from tests.
The actual change here is a little more complicated than the summary above.
What we want to do is have our generic inlining tests run under whatever
mode is the default. However, there are some tests that depend on the
presence of C++ inlining, which still has some rough edges. These tests have
been explicitly marked as -analyzer-ipa=inlining in preparation for a new
mode that limits inlining to C functions and blocks. This will be the
default until the false positives for C++ have been brought down to
manageable levels.

llvm-svn: 162317
2012-08-21 21:44:07 +00:00
Jordan Rose 81125c4497 [analyzer] Push "references are non-null" knowledge up to the common parent.
This reduces duplication across the Basic and Range constraint managers, and
keeps their internals free of dealing with the semantics of C++. It's still
a little unfortunate that the constraint manager is dealing with this at all,
but this is pretty much the only place to put it so that it will apply to all
symbolic values, even when embedded in larger expressions.

llvm-svn: 162313
2012-08-21 20:52:19 +00:00
Jordan Rose 075d5d2e99 [analyzer] Assume that reference symbols are non-null.
By doing this in the constraint managers, we can ensure that ANY reference
whose value we don't know gets the effect, even if it's not a top-level
parameter.

llvm-svn: 162246
2012-08-21 00:27:33 +00:00
Jordan Rose eaacff4826 [analyzer] More tests for "release and stop tracking".
Under GC, a release message is ignored, so "release and stop tracking" just
becomes "stop tracking". But CFRelease is still honored. This is the main
difference between ns_consumed and cf_consumed.

llvm-svn: 162234
2012-08-20 22:15:44 +00:00
Jordan Rose bda04301d4 [analyzer] Add a test for "release and stop tracking" behavior.
This is used to handle functions and methods that consume an argument
(annotated with the ns_consumed or cf_consumed attribute), but then the
argument's retain count may be further modified in a callback. We want
to warn about over-releasing, but we can't really track the object afterwards.

llvm-svn: 162221
2012-08-20 20:01:15 +00:00
Jordan Rose 0a9ea7c70d [analyzer] The result of && or || is always a 1 or 0.
Forgetting to at least cast the result was giving us Loc/NonLoc problems
in SValBuilder (hitting an assertion). But the standard (both C and C++)
does actually guarantee that && and || will result in the actual values
1 and 0, typed as 'int' in C and 'bool' in C++, and we can easily model that.

PR13461

llvm-svn: 162209
2012-08-20 17:04:45 +00:00
Hans Wennborg d799a2b3b9 Better wording for reference self-initialization warning.
llvm-svn: 162198
2012-08-20 08:52:22 +00:00
Jordan Rose a4309c941c [analyzer] Treat C++ 'throw' as a sink.
Our current handling of 'throw' is all CFG-based: it jumps to a 'catch' block
if there is one and the function exit block if not. But this doesn't really
get the right behavior when a function is inlined: execution will continue on
the caller's side, which is always the wrong thing to do.

Even within a single function, 'throw' completely skips any destructors that
are to be run. This is essentially the same problem as @finally -- a CFGBlock
that can have multiple entry points, whose exit points depend on whether it
was entered normally or exceptionally.

Representing 'throw' as a sink matches our current (non-)handling of @throw.
It's not a perfect solution, but it's better than continuing analysis in an
inconsistent or even impossible state.

<rdar://problem/12113713>

llvm-svn: 162157
2012-08-18 00:30:23 +00:00
Jordan Rose a97a99736e [analyzer] Treat @throw as a sink (stop processing).
The CFG approximates @throw as a return statement, but that's not good
enough in inlined functions. Moreover, since Objective-C exceptions are
usually considered fatal, we should be suppressing leak warnings like we
do for calls to noreturn functions (like abort()).

The comments indicate that we were probably intending to do this all along;
it may have been inadvertantly changed during a refactor at one point.

llvm-svn: 162156
2012-08-18 00:30:20 +00:00
Jordan Rose 9844ab8992 [analyzer] Make BlockDataRegions typed, so that they have DynamicTypeInfo.
Fixes <rdar://problem/12119814>

llvm-svn: 162123
2012-08-17 20:16:34 +00:00
Hans Wennborg e1fdb059c6 Warn about self-initialization of references.
Initializing a reference with itself, e.g. "int &a = a;" seems like a
very bad idea.

llvm-svn: 162093
2012-08-17 10:12:33 +00:00
Richard Smith 43b550f7fe Fix test so that it doesn't keep failing forever when it's failed once.
llvm-svn: 162077
2012-08-17 04:05:25 +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
Jordan Rose 6ee44e1f03 [analyzer] Look through all casts when trying to track constraints.
Previously, we were losing path notes (in both text and plist form)
because the interesting DeclRefExpr was buried in a cast.

llvm-svn: 161999
2012-08-16 00:03:33 +00:00
Jordan Rose 83e4049d39 [analyzer] If we call a C++ method on an object, assume it's non-null.
This is analogous to our handling of pointer dereferences: if we
dereference a pointer that may or may not be null, we assume it's non-null
from then on.

While some implementations of C++ (including ours) allow you to call a
non-virtual method through a null pointer of object type, it is technically
disallowed by the C++ standard, and should not prune out any real paths in
practice.

  [class.mfct.non-static]p1: A non-static member function may be called
    for an object of its class type, or for an object of a class derived
    from its class type...
  (a null pointer value does not refer to an object)

We can also make the same assumption about function pointers.

llvm-svn: 161992
2012-08-15 21:56:23 +00:00
Jordan Rose e9753b0640 [analyzer] Even if we are not inlining a virtual call, still invalidate!
Fixes a mistake introduced in r161916.

llvm-svn: 161987
2012-08-15 21:05:15 +00:00
Jordan Rose 5fc5da0578 [analyzer] Correctly devirtualize virtual method calls in constructors.
This is the other half of C++11 [class.cdtor]p4 (the destructor side
was added in r161915). This also fixes an issue with post-call checks
where the 'this' value was already being cleaned out of the state, thus
being omitted from a reconstructed CXXConstructorCall.

llvm-svn: 161981
2012-08-15 20:07:17 +00:00
Jordan Rose 31c3fa9c24 [analyzer] Only adjust the type of 'this' when we devirtualize a method call.
With reinterpret_cast, we can get completely unrelated types in a region
hierarchy together; this was resulting in CXXBaseObjectRegions being layered
directly on an (untyped) SymbolicRegion, whose symbol was from a completely
different type hierarchy. This was what was causing the internal buildbot to
fail.

Reverts r161911, which merely masked the problem.

llvm-svn: 161960
2012-08-15 17:33:34 +00:00
Jordan Rose 5132aaeb04 [analyzer] Don't inline dynamic-dispatch methods unless -analyzer-ipa=dynamic.
Previously we were checking -analyzer-ipa=dynamic-bifurcate only, and
unconditionally inlining everything else that had an available definition,
even under -analyzer-ipa=inlining (but not under -analyzer-ipa=none).

llvm-svn: 161916
2012-08-15 00:52:00 +00:00
Jordan Rose 0f6d63be06 [analyzer] Correctly devirtualize virtual method calls in destructors.
C++11 [class.cdtor]p4: When a virtual function is called directly or
  indirectly from a constructor or from a destructor, including during
  the construction or destruction of the class’s non-static data members,
  and the object to which the call applies is the object under
  construction or destruction, the function called is the final overrider
  in the constructor's or destructor's class and not one overriding it in
  a more-derived class.

llvm-svn: 161915
2012-08-15 00:51:56 +00:00
Anna Zaks 6ddb6b1a9a [analyzer]Assume that the properties cannot be overridden when dot
syntax is used.

llvm-svn: 161889
2012-08-14 19:19:18 +00:00
Anna Zaks 799ad50ffb [analyzer] Address Jordan's comments for r161822, r161683.
Add a TODO test case for r161822 - calling self from a class method.

Remove a TODO comment for r161683 - value2 is not a property - we just
have method names that look like they are getters/setters for a
property.

llvm-svn: 161884
2012-08-14 18:35:06 +00:00
Anna Zaks 23665a1bcf [analyzer] Teach live variable analyzes that super uses self pointer.
llvm-svn: 161822
2012-08-14 00:36:20 +00:00
Jordan Rose 710f6b1259 [analyzer] Be more careful when downcasting for devirtualization.
Virtual base regions are never layered, so simply stripping them off won't
necessarily get you to the correct casted class. Instead, what we want is
the same logic for evaluating dynamic_cast: strip off base regions if possible,
but add new base regions if necessary.

llvm-svn: 161808
2012-08-13 23:46:01 +00:00
Jordan Rose 574ef152fc [analyzer] Handle dynamic_casts that turn out to be upcasts.
This can occur with multiple inheritance, which jumps from one parent to
the other, and with virtual inheritance, since virtual base regions always
wrap the actual object and can't be nested within other base regions.

This also exposed some incorrect logic for multiple inheritance: even if B
is known not to derive from C, D might still derive from both of them.

llvm-svn: 161798
2012-08-13 22:11:42 +00:00
Jordan Rose 07a7ed80cb [analyzer] Don't strip CXXBaseObjectRegions when checking dynamic_casts.
...and /do/ strip CXXBaseObjectRegions when casting to a virtual base class.

This allows us to enforce the invariant that a CXXBaseObjectRegion can always
provide an offset for its base region if its base region has a known class
type, by only allowing virtual bases and direct non-virtual bases to form
CXXBaseObjectRegions.

This does mean some slight problems for our modeling of dynamic_cast, which
needs to be resolved by finding a path from the current region to the class
we're trying to cast to.

llvm-svn: 161797
2012-08-13 22:11:34 +00:00
Jordan Rose 02e5309b35 [analyzer] Strip CXXBaseObjectRegions when devirtualizing method calls.
This was causing a crash when we tried to re-apply a base object region to
itself. It probably also caused incorrect offset calculations in RegionStore.

PR13569 / <rdar://problem/12076683>

llvm-svn: 161710
2012-08-10 22:26:46 +00:00
Jordan Rose 51bcb226a2 [analyzer] Try to devirtualize even if the static callee has no definition.
This mostly affects pure virtual methods, but would also affect parent
methods defined inline in the header when analyzing the child's source file.

llvm-svn: 161709
2012-08-10 22:26:43 +00:00
Jordan Rose 13937b1d7a [analyzer] Add clang_analyzer_checkInlined for debugging purposes.
This check is also accessible through the debug.ExprInspection checker.
Like clang_analyzer_eval, you can use it to test the analyzer engine's
current state; the argument should be true or false to indicate whether or
not you expect the function to be inlined.

When used in the positive case (clang_analyzer_checkInlined(true)), the
analyzer prints the message "TRUE" if the function is ever inlined. However,
clang_analyzer_checkInlined(false) should never print a message; this asserts
that there should be no paths on which the current function is inlined, but
then there are no paths on which to print a message! (If the assertion is
violated, the message "FALSE" will be printed.)

This asymmetry comes from the fact that the only other chance to print a
message is when the function is analyzed as a top-level function. However,
when we do that, we can't be sure it isn't also inlined elsewhere (such as
in a recursive function, or if we want to analyze in both general or
specialized cases). Rather than have all checkInlined calls have an appended,
meaningless "FALSE" or "TOP-LEVEL" case, there is just no message printed.

void clang_analyzer_checkInlined(int);

For debugging purposes only!

llvm-svn: 161708
2012-08-10 22:26:29 +00:00
Anna Zaks d4e65373f3 [analyzer] ObjC Inlining: add tests for ivars and properties.
TODO:
 - Handle @syncronized properties.
 - Always inline properties declared publicly (do not split the path).
This is tricky since there is no mapping from a Decl to the property in
the AST as far as I can tell.

llvm-svn: 161683
2012-08-10 18:56:01 +00:00
Anna Zaks 75f49a9c07 [analyzer] Track if a region can be a subclass in the dynamic type info.
When object is allocated with alloc or init, we assume it cannot be a
subclass (currently used only for bifurcation purposes).

llvm-svn: 161682
2012-08-10 18:55:58 +00:00
Anna Zaks 920af014c1 [analyzer] Optimize dynamic dispatch bifurcation by detecting the cases
when we don't need to split.

In some cases we know that a method cannot have a different
implementation in a subclass:
 - the class is declared in the main file (private)
 - all the method declarations (including the ones coming from super
classes) are in the main file.

This can be improved further, but might be enough for the heuristic.
(When we are too aggressive splitting the state, efficiency suffers.
When we fail to split the state coverage might suffer.)

llvm-svn: 161681
2012-08-10 18:55:53 +00:00
Jordan Rose a44a55a8f2 [analyzer] Cluster bindings in RegionStore by base region.
This should speed up activities that need to access bindings by cluster,
such as invalidation and dead-bindings cleaning. In some cases all we save
is the cost of building the region cluster map, but other times we can
actually avoid traversing the rest of the store.

In casual testing, this produced a speedup of nearly 10% analyzing SQLite,
with /less/ memory used.

llvm-svn: 161636
2012-08-09 22:55:51 +00:00
Jordan Rose 996d309fb7 [analyzer] A CXXBaseObjectRegion should correspond to a DIRECT base.
An ASTContext's RecordLayoutInfo can only be used to look up offsets of
direct base classes, and we need the offset to make non-symbolic bindings
in RegionStore. This change makes sure that we have one layer of
CXXBaseObjectRegion for each base we are casting through.

This was causing crashes on an internal buildbot.

llvm-svn: 161621
2012-08-09 21:24:02 +00:00