This was only used by OSAtomicChecker and makes it more
difficult to update values for expressions that the environment
may look through instead (it's not the same as IgnoreParens).
With this gone, we can have bindExpr bind to the inner
expression that getSVal will find.
Groundwork for <rdar://problem/12137950>
llvm-svn: 165866
I believe the removed assert in CheckerManager says it best:
InlineCall is a special hacky callback to allow intrusive
evaluation of the call (which simulates inlining). It is
currently only used by OSAtomicChecker and should go away
at some point.
OSAtomicChecker has gone away; inlineCall can now go away as well!
llvm-svn: 165865
This time, actually uncomment the code that's supposed to fix the problem.
This reverts r165671 / 8ceb837585ed973dc36fba8dfc57ef60fc8f2735.
llvm-svn: 165676
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
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
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
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
These functions are store-agnostic, and would benefit from information in
DynamicTypeInfo but gain nothing from the store type.
No intended functionality change.
llvm-svn: 165078
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
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
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
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
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
It is possible and valid to have a state manager and associated objects
without having a SubEngine or checkers.
Patch by Olaf Krzikalla!
llvm-svn: 164947
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
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
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
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
No tests, but this allows the optimization of removing dead constraints.
We can then add tests that we don't do this prematurely.
<rdar://problem/12333297>
Note: the added FIXME to investigate SymbolRegionValue liveness is
tracked by <rdar://problem/12368183>. This patch does not change the
existing behavior.
llvm-svn: 164621
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
Before, PathDiagnosticConsumers that did not support actual path output
would (sensibly) cause the generation of the full path to be skipped.
However, BugReporterVisitors may want to see the path in order to mark a
BugReport as invalid.
Now, even for a path generation scheme of 'None' we will still create a
trimmed graph and walk backwards through the bug path, doing no work other
than passing the nodes to the BugReporterVisitors. This isn't cheap, but
it's necessary to properly do suppression when the first path consumer does
not support path notes.
In the future, we should try only generating the path and visitor-provided
path notes once, or at least only creating the trimmed graph once.
llvm-svn: 164447
This is intended to allow visitors to make decisions about whether a
BugReport is likely a false positive. Currently there are no visitors
making use of this feature, so there are no tests.
When a BugReport is marked invalid, the invalidator must provide a key
that identifies the invaliation (intended to be the visitor type and a
context pointer of some kind). This allows us to reverse the decision
later on. Being able to reverse a decision about invalidation gives us more
flexibility, and allows us to formulate conditions like "this report is
invalid UNLESS the original argument is 'foo'". We can use this to
fine-tune our false-positive suppression (coming soon).
llvm-svn: 164446
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
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
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
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
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
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
in NSException to a helper object in libAnalysis that can also
be used by Sema. Not sure if the predicate name 'isImplicitNoReturn'
is the best one, but we can massage that later.
No functionality change.
llvm-svn: 163759
Jordan Rose