70 Commits

Author SHA1 Message Date
Eli Friedman
34866c7719 Change the representation of builtin functions in the AST
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call.  Fixes PR13195.

llvm-svn: 162962
2012-08-31 00:14:07 +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
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
Ted Kremenek
d94854a42e Rename 'currentX' to 'currX' throughout analyzer and libAnalysis.
Also rename 'getCurrentBlockCounter()' to 'blockCount()'.

This ripples a bunch of code simplifications; mostly aesthetic,
but makes the code a bit tighter.

llvm-svn: 162349
2012-08-22 06:26:15 +00:00
Ted Kremenek
d227833cba Rename 'getConjuredSymbol*' to 'conjureSymbol*'.
No need to have the "get", the word "conjure" is a verb too!
Getting a conjured symbol is the same as conjuring one up.

This shortening is largely cosmetic, but just this simple changed
cleaned up a handful of lines, making them less verbose.

llvm-svn: 162348
2012-08-22 06:26:06 +00:00
Ted Kremenek
1afcb7442f Remove Store::bindDecl() and Store::bindDeclWithNoInit(), and
all forwarding methods.

This functionality is already covered by bindLoc().

llvm-svn: 162346
2012-08-22 06:00:18 +00:00
Jordan Rose
4b4613cbec [analyzer] Replace boolean IsSink parameters with 'generateSink' methods.
Generating a sink is significantly different behavior from generating a
normal node, and a simple boolean parameter can be rather opaque. Per
offline discussion with Anna, adding new generation methods is the
clearest way to communicate intent.

No functionality change.

llvm-svn: 162215
2012-08-20 18:43:42 +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
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
Anna Zaks
472dbcf156 [analyzer] Add a checker to manage dynamic type propagation.
Instead of sprinkling dynamic type info propagation throughout
ExprEngine, the added checker would add the more precise type
information on known APIs (Ex: ObjC alloc, new) and propagate
the type info in other cases (ex: ObjC init method, casts (the second is
not implemented yet)).

Add handling of ObjC alloc, new and init to the checker.

llvm-svn: 161357
2012-08-06 23:25:39 +00:00
Anna Zaks
150843b87e [analyzer] ObjC Inlining: Start tracking dynamic type info in the GDM
In the following code, find the type of the symbolic receiver by
following it and updating the dynamic type info in the state when we
cast the symbol from id to MyClass *.

  MyClass *a = [[self alloc] init];
  return 5/[a testSelf];

llvm-svn: 161264
2012-08-03 21:43:37 +00:00
Ted Kremenek
313c2ff375 Look at the preceding CFGBlock for the expression to load from in ExprEngine::VisitGuardedExpr
instead of walking to the preceding PostStmt node.  There are cases where the last evaluated
expression does not appear in the ExplodedGraph.

Fixes PR 13466.

llvm-svn: 160819
2012-07-26 22:23:41 +00:00
Jordan Rose
20edae8749 [analyzer] Don't crash on array constructors and destructors.
This workaround is fairly lame: we simulate the first element's constructor
and destructor and rely on the region invalidation to "initialize" the rest
of the elements.

llvm-svn: 160809
2012-07-26 20:04:25 +00:00
Ted Kremenek
bb81ffb342 Update ExprEngine's handling of ternary operators to find the ternary expression
value by scanning the path, rather than assuming we have visited the '?:' operator
as a terminator (which sets a value indicating which expression to grab the
final ternary expression value from).

llvm-svn: 160760
2012-07-25 21:58:25 +00:00
Jordan Rose
5089f3b398 [analyzer] Handle new-expressions with initializers for scalars.
<rdar://problem/11818967>

llvm-svn: 160328
2012-07-16 23:38:09 +00:00
Daniel Jasper
6b5a4fcc07 Prevent unused-variable warning in optimized builds.
llvm-svn: 160257
2012-07-16 10:25:15 +00:00
Ted Kremenek
b50e716bac Refine CFG so that '&&' and '||' don't lead to extra confluence points when used in a branch, but
instead push the terminator for the branch down into the basic blocks of the subexpressions of '&&' and '||'
respectively.  This eliminates some artifical control-flow from the CFG and results in a more
compact CFG.

Note that this patch only alters the branches 'while', 'if' and 'for'.  This was complex enough for
one patch.  The remaining branches (e.g., do...while) can be handled in a separate patch, but they
weren't immediately tackled because they were less important.

It is possible that this patch introduces some subtle bugs, particularly w.r.t. to destructor placement.
I've tried to audit these changes, but it is also known that the destructor logic needs some refinement
in the area of '||' and '&&' regardless (i.e., their are known bugs).

llvm-svn: 160218
2012-07-14 05:04:10 +00:00
Jordan Rose
eab627b951 [analyzer] Construct stack variables directly in their VarDecl.
Also contains a number of tweaks to inlining that are necessary
for constructors and destructors. (I have this enabled on a private
branch, but it is very much unstable.)

llvm-svn: 160023
2012-07-10 22:08:01 +00:00
Jordan Rose
832c2134a9 [analyzer] Add a comment: why we treat array compound literals as lvalues.
llvm-svn: 158681
2012-06-18 21:31:27 +00:00
Jordan Rose
b4712d142a [analyzer] Array CompoundLiteralExprs need to be treated like lvalues.
llvm-svn: 158588
2012-06-16 01:28:03 +00:00
Jordan Rose
2fdc07ee89 Revert "[analyzer] Treat LValueBitCasts like regular pointer bit casts."
This does not actually give us the right behavior for reinterpret_cast
of references. Reverting so I can think about it some more.

This reverts commit 50a75a6e26a49011150067adac556ef978639fe6.

llvm-svn: 158341
2012-06-12 00:20:22 +00:00
Jordan Rose
ca00b28a47 [analyzer] Treat LValueBitCasts like regular pointer bit casts.
These casts only appear in very well-defined circumstances, in which the
target of a reinterpret_cast or a function formal parameter is an lvalue
reference. According to the C++ standard, the following are equivalent:

 reinterpret_cast<T&>( x)
*reinterpret_cast<T*>(&x)

[expr.reinterpret.cast]p11

llvm-svn: 158338
2012-06-11 23:20:52 +00:00
Anna Zaks
6a65819ba3 [analyzer] Don't crash on LValBitCast
llvm-svn: 157478
2012-05-25 16:02:16 +00:00
Anna Zaks
fc1d4bdc4f [analyzer] Bind UnknownVal to InitListExpr for unsupported types
(ex: float).

llvm-svn: 157211
2012-05-21 22:07:00 +00:00
Anna Zaks
94a7b849a2 [analyzer] For locations, use isGLValue() instead of isLValue().
llvm-svn: 157088
2012-05-19 00:22:07 +00:00
Ted Kremenek
fd727748bd Explicitly model capturing variables for blocks in the static analyzer. Fixes <rdar://problem/11125868>.
llvm-svn: 156211
2012-05-04 21:48:42 +00:00
Anna Zaks
1655aee1e3 [analyzer] Conjure a symbol to ensure we can identify pointer arithmetic
We need to identify the value of ptr as
ElementRegion (result of pointer arithmetic) in the following code.
However, before this commit '(2-x)' evaluated to Unknown value, and as
the result, 'p + (2-x)' evaluated to Unknown value as well.

int *p = malloc(sizeof(int));
ptr = p + (2-x);

llvm-svn: 156052
2012-05-03 02:13:56 +00:00
Anna Zaks
f36a6f54ae [analyzer] dynamic_cast Simplify null value generation.
As per Jordy's review. Creating a symbol here is more flexible; however
I could not come up with an example where it was needed. (What
constrains can be added on of the symbol constrained to 0?)

llvm-svn: 154542
2012-04-11 22:20:07 +00:00
Anna Zaks
02ecae9282 [analyzer] dynamic_cast: Better model cast from a reference.
Generate a sink when the dynamic_cast from a reference fails to
represent a thrown exception.

llvm-svn: 154438
2012-04-10 21:29:03 +00:00
Anna Zaks
3bc6809ecb [analyzer] Add support for C++ dynamic_cast.
Simulate the C++ dynamic_cast in the analyzer.

llvm-svn: 154434
2012-04-10 20:59:00 +00:00
Ted Kremenek
a85f38ba3a Rework ExprEngine::evalLoad and clients (e.g. VisitBinaryOperator) so that when we generate a new ExplodedNode
we use the same Expr* as the one being currently visited.  This is preparation for transitioning to having
ProgramPoints refer to CFGStmts.

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

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

llvm-svn: 154214
2012-04-06 22:10:18 +00:00
Ted Kremenek
34ac1cf3cd Handle symbolicating a reference in an initializer expression that we don't understand.
llvm-svn: 154084
2012-04-05 05:56:31 +00:00
David Blaikie
bbafb8a745 Unify naming of LangOptions variable/get function across the Clang stack (Lex to AST).
The member variable is always "LangOpts" and the member function is always "getLangOpts".

Reviewed by Chris Lattner

llvm-svn: 152536
2012-03-11 07:00:24 +00:00
Douglas Gregor
ed90df3800 Generate an AST for the conversion from a lambda closure type to a
block pointer that returns a block literal which captures (by copy)
the lambda closure itself. Some aspects of the block literal are left
unspecified, namely the capture variable (which doesn't actually
exist) and the body (which will be filled in by IRgen because it can't
be written as an AST).

Because we're switching to this model, this patch also eliminates
tracking the copy-initialization expression for the block capture of
the conversion function, since that information is now embedded in the
synthesized block literal. -1 side tables FTW.

llvm-svn: 151131
2012-02-22 05:02:47 +00:00
Ted Kremenek
d519cae8aa Have conjured symbols depend on LocationContext, to add context sensitivity for functions called more than once.
llvm-svn: 150849
2012-02-17 23:13:45 +00:00
John McCall
c62bb39142 Split reinterpret_casts of member pointers out from CK_BitCast; this
is general goodness because representations of member pointers are
not always equivalent across member pointer types on all ABIs
(even though this isn't really standard-endorsed).

Take advantage of the new information to teach IR-generation how
to do these reinterprets in constant initializers.  Make sure this
works when intermingled with hierarchy conversions (although
this is not part of our motivating use case).  Doing this in the
constant-evaluator would probably have been better, but that would
require a *lot* of extra structure in the representation of
constant member pointers:  you'd really have to track an arbitrary
chain of hierarchy conversions and reinterpretations in order to
get this right.  Ultimately, this seems less complex.  I also
wasn't quite sure how to extend the constant evaluator to handle
foldings that we don't actually want to treat as extended
constant expressions.

llvm-svn: 150551
2012-02-15 01:22:51 +00:00
Ted Kremenek
76978f9d6c Remove recusive expression visitation in ExprEngine::VisitIncrementDecrementOperator().
llvm-svn: 150511
2012-02-14 21:38:30 +00:00
Ted Kremenek
89dbd3ba40 Remove recursive visitation in ExprEngine for UO_Not, UO_Minus, UO_LNot.
llvm-svn: 150509
2012-02-14 21:31:00 +00:00
Ted Kremenek
8c8578c0b8 Remove recursive visitation in ExprEngine for UO_Deref, UO_AddrOf, and UO_Extension.
llvm-svn: 150506
2012-02-14 21:27:05 +00:00
Ted Kremenek
c14557fb6a Remove ExprEngine recursive visitation of unary UO_Imag operation.
llvm-svn: 150505
2012-02-14 21:27:02 +00:00
Ted Kremenek
b5d87d8843 Further remove some recursive visitiation in ExprEngine that is no longer needed because the CFG is fully linearized.
llvm-svn: 150504
2012-02-14 21:26:59 +00:00
Ted Kremenek
49b1e38e4b Change references to 'const ProgramState *' to typedef 'ProgramStateRef'.
At this point this is largely cosmetic, but it opens the door to replace
ProgramStateRef with a smart pointer that more eagerly acts in the role
of reclaiming unused ProgramState objects.

llvm-svn: 149081
2012-01-26 21:29:00 +00:00
David Chisnall
fa35df628a Some improvements to the handling of C11 atomic types:
- Add atomic-to/from-nonatomic cast types
- Emit atomic operations for arithmetic on atomic types
- Emit non-atomic stores for initialisation of atomic types, but atomic stores and loads for every other store / load
- Add a __atomic_init() intrinsic which does a non-atomic store to an _Atomic() type.  This is needed for the corresponding C11 stdatomic.h function.
- Enables the relevant __has_feature() checks.  The feature isn't 100% complete yet, but it's done enough that we want people testing it.

Still to do:

- Make the arithmetic operations on atomic types (e.g. Atomic(int) foo = 1; foo++;) use the correct LLVM intrinsic if one exists, not a loop with a cmpxchg.
- Add a signal fence builtin
- Properly set the fenv state in atomic operations on floating point values
- Correctly handle things like _Atomic(_Complex double) which are too large for an atomic cmpxchg on some platforms (this requires working out what 'correctly' means in this context)
- Fix the many remaining corner cases

llvm-svn: 148242
2012-01-16 17:27:18 +00:00
Ted Kremenek
632e3b7ee2 [analyzer] Make the entries in 'Environment' context-sensitive by making entries map from
(Stmt*,LocationContext*) pairs to SVals instead of Stmt* to SVals.

This is needed to support basic IPA via inlining.  Without this, we cannot tell
if a Stmt* binding is part of the current analysis scope (StackFrameContext) or
part of a parent context.

This change introduces an uglification of the use of getSVal(), and thus takes
two steps forward and one step back.  There are also potential performance implications
of enlarging the Environment.  Both can be addressed going forward by refactoring the
APIs and optimizing the internal representation of Environment.  This patch
mainly introduces the functionality upon when we want to build upon (and clean up).

llvm-svn: 147688
2012-01-06 22:09:28 +00:00
Richard Smith
5fab0c9e1a Small refactoring and simplification of constant evaluation and some of its
clients. No functionality change.

llvm-svn: 147318
2011-12-28 19:48:30 +00:00
Anna Zaks
2d2999821b [analyzer] Simplify the condition.
This is a fixup for r145832.

The extra clauses do not matter after we remove the dependency on canReasonAbout(InitVal) in r145832.

llvm-svn: 145856
2011-12-05 21:33:01 +00:00
Anna Zaks
a636fbe73f [analyzer] Remove all uses of ConstraintManager::canResonAbout() from
ExprEngine.

Teach SimpleConstraintManager::assumeSymRel() to propagate constraints
to symbolic expressions.

+ One extra warning (real bug) is now generated due to enhanced
assumeSymRel().

llvm-svn: 145832
2011-12-05 18:58:25 +00:00
Anna Zaks
51090d5f7f [analyzer] First step toward removing
ConstraintManager::canReasonAbout() from the ExprEngine.

ExprEngine should not care if the constraint solver can reason about
something or not. The solver should be able to handle all the SymExprs.

To do this, the solver should be able to keep track of not only the
SymbolData but of all SymExprs. This is why we change SymbolRef to be an
alias of SymExpr*. When encountering an expression it cannot simplify,
the solver should just add the constraints to it.

llvm-svn: 145831
2011-12-05 18:58:19 +00:00
Anna Zaks
040ddfedc0 [analyzer] Do not conjure a symbol when we need to propagate taint.
When the solver and SValBuilder cannot reason about symbolic expressions (ex: (x+1)*y ), the analyzer conjures a new symbol with no ties to the past. This helps it to recover some path-sensitivity. However, this breaks the taint propagation.

With this commit, we are going to construct the expression even if we cannot reason about it later on if an operand is tainted.

Also added some comments and asserts.

llvm-svn: 144932
2011-11-17 23:07:28 +00:00