People have been incorrectly using "-analyzer-disable-checker" to
silence analyzer warnings on a file, when analyzing a project. Add
the "-analyzer-disable-all-checks" option, which would allow the
suppression and suggest it as part of the error message for
"-analyzer-disable-checker". The idea here is to compose this with
"--analyze" so that users can selectively opt out specific files from
static analysis.
llvm-svn: 216763
I suspect llvm::ilist should take elements by unique_ptr, since it does
take ownership of the element (by stitching it into the linked list) -
one day.
llvm-svn: 216761
Again, if shared ownership is the right model here (I assume it is,
given graph algorithms & such) this could be tidied up (the 'release'
call removed in favor of something safer) by having
IntrunsiveRefCntPointer constructible from a unique_ptr.
(& honestly I'd probably favor taking a page out of shared_ptr's book,
allowing implicit construction from a unique_ptr rvalue, and only allow
explicit from a raw pointer - currently IntrusiveRefCntPointer can
implicitly own from a raw pointer, which seems unsafe)
llvm-svn: 216752
Currently the analyzer lazily models some functions using 'BodyFarm',
which constructs a fake function implementation that the analyzer
can simulate that approximates the semantics of the function when
it is called. BodyFarm does this by constructing the AST for
such definitions on-the-fly. One strength of BodyFarm
is that all symbols and types referenced by synthesized function
bodies are contextual adapted to the containing translation unit.
The downside is that these ASTs are hardcoded in Clang's own
source code.
A more scalable model is to allow these models to be defined as source
code in separate "model" files and have the analyzer use those
definitions lazily when a function body is needed. Among other things,
it will allow more customization of the analyzer for specific APIs
and platforms.
This patch provides the initial infrastructure for this feature.
It extends BodyFarm to use an abstract API 'CodeInjector' that can be
used to synthesize function bodies. That 'CodeInjector' is
implemented using a new 'ModelInjector' in libFrontend, which lazily
parses a model file and injects the ASTs into the current translation
unit.
Models are currently found by specifying a 'model-path' as an
analyzer option; if no path is specified the CodeInjector is not
used, thus defaulting to the current behavior in the analyzer.
Models currently contain a single function definition, and can
be found by finding the file <function name>.model. This is an
initial starting point for something more rich, but it bootstraps
this feature for future evolution.
This patch was contributed by Gábor Horváth as part of his
Google Summer of Code project.
Some notes:
- This introduces the notion of a "model file" into
FrontendAction and the Preprocessor. This nomenclature
is specific to the static analyzer, but possibly could be
generalized. Essentially these are sources pulled in
exogenously from the principal translation.
Preprocessor gets a 'InitializeForModelFile' and
'FinalizeForModelFile' which could possibly be hoisted out
of Preprocessor if Preprocessor exposed a new API to
change the PragmaHandlers and some other internal pieces. This
can be revisited.
FrontendAction gets a 'isModelParsingAction()' predicate function
used to allow a new FrontendAction to recycle the Preprocessor
and ASTContext. This name could probably be made something
more general (i.e., not tied to 'model files') at the expense
of losing the intent of why it exists. This can be revisited.
- This is a moderate sized patch; it has gone through some amount of
offline code review. Most of the changes to the non-analyzer
parts are fairly small, and would make little sense without
the analyzer changes.
- Most of the analyzer changes are plumbing, with the interesting
behavior being introduced by ModelInjector.cpp and
ModelConsumer.cpp.
- The new functionality introduced by this change is off-by-default.
It requires an analyzer config option to enable.
llvm-svn: 216550
the no-arguments case. Don't expand this to an __attribute__((nonnull(A, B,
C))) attribute, since that does the wrong thing for function templates and
varargs functions.
In passing, fix a grammar error in the diagnostic, a crash if
__attribute__((nonnull(N))) is applied to a varargs function,
a bug where the same null argument could be diagnosed multiple
times if there were multiple nonnull attributes referring to it,
and a bug where nonnull attributes would not be accumulated correctly
across redeclarations.
llvm-svn: 216520
The ObjCDealloc checker is currently disabled because it was too aggressive, but this
is a good first step in getting it back to a useful state.
Patch by David Kilzer!
llvm-svn: 216272
Yet more problems due to the missing CXXBindTemporaryExpr in the CFG for
default arguments.
Unfortunately we cannot just switch off inserting temporaries for the
corresponding default arguments, as that breaks existing tests
(test/SemaCXX/return-noreturn.cpp:245).
llvm-svn: 215554
In cases like:
struct C { ~C(); }
void f(C c = C());
void t() {
f();
}
We currently do not add the CXXBindTemporaryExpr for the temporary (the
code mentions that as the default parameter expressions are owned by
the declaration, we'd otherwise add the same expression multiple times),
but we add the temporary destructor pointing to the CXXBindTemporaryExpr.
We need to fix that before we can re-enable the assertion.
llvm-svn: 215357
After post-commit review and community discussion, this seems like a
reasonable direction to continue, making ownership semantics explicit in
the source using the type system.
llvm-svn: 215323
Summary: I was going to fix the use of raw pointer ownership in "takeGraph" when I realized that function was unused and the whole ExplodedGraph could just be owned by value without the std::unique_ptr indirection at all.
Reviewers: jordan_rose
Differential Revision: http://reviews.llvm.org/D4833
llvm-svn: 215257
Changes to the original patch:
- model the CFG for temporary destructors in conditional operators so that
the destructors of the true and false branch are always exclusive. This
is necessary because we must not have impossible paths for the path
based analysis to work.
- add multiple regression tests with ternary operators
Original description:
Fix modelling of non-lifetime-extended temporary destructors in the
analyzer.
Changes to the CFG:
When creating the CFG for temporary destructors, we create a structure
that mirrors the branch structure of the conditionally executed
temporary constructors in a full expression.
The branches we create use a CXXBindTemporaryExpr as terminator which
corresponds to the temporary constructor which must have been executed
to enter the destruction branch.
2. Changes to the Analyzer:
When we visit a CXXBindTemporaryExpr we mark the CXXBindTemporaryExpr as
executed in the state; when we reach a branch that contains the
corresponding CXXBindTemporaryExpr as terminator, we branch out
depending on whether the corresponding CXXBindTemporaryExpr was marked
as executed.
llvm-svn: 215096
This reverts commit r214962 because after the change the
following code doesn't compile with -Wreturn-type -Werror.
#include <cstdlib>
class NoReturn {
public:
~NoReturn() __attribute__((noreturn)) { exit(1); }
};
int check() {
true ? NoReturn() : NoReturn();
}
llvm-svn: 214998
1. Changes to the CFG:
When creating the CFG for temporary destructors, we create a structure
that mirrors the branch structure of the conditionally executed
temporary constructors in a full expression.
The branches we create use a CXXBindTemporaryExpr as terminator which
corresponds to the temporary constructor which must have been executed
to enter the destruction branch.
2. Changes to the Analyzer:
When we visit a CXXBindTemporaryExpr we mark the CXXBindTemporaryExpr as
executed in the state; when we reach a branch that contains the
corresponding CXXBindTemporaryExpr as terminator, we branch out
depending on whether the corresponding CXXBindTemporaryExpr was marked
as executed.
llvm-svn: 214962
It's also possible to just write "= nullptr", but there's some question
of whether that's as readable, so I leave it up to authors to pick which
they prefer for now. If we want to discuss standardizing on one or the
other, we can do that at some point in the future.
llvm-svn: 213439
This reverts commit r213307.
Reverting to have some on-list discussion/confirmation about the ongoing
direction of smart pointer usage in the LLVM project.
llvm-svn: 213325
(after fixing a bug in MultiplexConsumer I noticed the ownership of the
nested consumers was implemented with raw pointers - so this fixes
that... and follows the source back to its origin pushing unique_ptr
ownership up through there too)
llvm-svn: 213307
The rewrite facility's footprint is small so it's not worth going to these
lengths to support disabling at configure time, particularly since key compiler
features now depend on it.
Meanwhile the Objective-C rewriters have been moved under the
ENABLE_CLANG_ARCMT umbrella for now as they're comparatively heavy and still
potentially worth excluding from lightweight builds.
Tests are now passing with any combination of feature flags. The flags
historically haven't been tested by LLVM's build servers so caveat emptor.
llvm-svn: 213171
This new checker, alpha.core.TestAfterDivZero, catches issues like this:
int sum = ...
int avg = sum / count; // potential division by zero...
if (count == 0) { ... } // ...caught here
Because the analyzer does not necessarily explore /all/ paths through a program,
this check is restricted to only work on zero checks that immediately follow a
division operation (/ % /= %=). This could later be expanded to handle checks
dominated by a division operation but not necessarily in the same CFG block.
Patch by Anders Rönnholm! (with very minor modifications by me)
llvm-svn: 212731
This silences false positives (leaks, use of uninitialized value) in simple
code that uses containers such as std::vector and std::list. The analyzer
cannot reason about the internal invariances of those data structures which
leads to false positives. Until we come up with a better solution to that
problem, let's just not inline the methods of the containers and allow objects
to escape whenever such methods are called.
This just extends an already existing flag "c++-container-inlining" and applies
the heuristic not only to constructors and destructors of the containers, but
to all of their methods.
We have a bunch of distinct user reports all related to this issue
(radar://16058651, radar://16580751, radar://16384286, radar://16795491
[PR19637]).
llvm-svn: 211832
Doing this caused us to mistakenly think we'd seen a particular state before
when we actually hadn't, which resulted in false negatives. Credit to
Rafael Auler for discovering this issue!
llvm-svn: 211209
This reverts commit r211096. Looks like it broke the msvc build:
SemaOpenMP.cpp(140) : error C4519: default template arguments are only allowed on a class template
llvm-svn: 211113
instead of report-XXXXXX.html, scan-build/clang analyzer generate
report-<filename>-<function, method name>-<function position>-<id>.html.
(id = i++ for several issues found in the same function/method)
llvm-svn: 210970
Fixes a crash in Retain Count checker error reporting logic by handing
the allocation statement retrieval from a BlockEdge program point.
Also added a simple CFG dump routine for debugging.
llvm-svn: 210960
will never be true in a well-defined context. The checking for null pointers
has been moved into the caller logic so it does not rely on undefined behavior.
llvm-svn: 210498
This applies to __attribute__((pure)) as well, but 'const' is more interesting
because many of our builtins are marked 'const'.
PR19661
llvm-svn: 208154
BugReport doesn't take ownership of the bug type, so let the checker own the
the bug type. (Requires making the bug type mutable, which is icky, but which
is also what other checkers do.)
llvm-svn: 208110
Document and simplify ResolveCondition.
1. Introduce a temporary special case for temporary desctructors when resolving
the branch condition - in an upcoming patch, alexmc will change temporary
destructor conditions to not run through this logic, in which case we can remove
this (marked as FIXME); this currently fixes a crash.
2. Simplify ResolveCondition; while documenting the function, I noticed that it
always returns the last statement - either that statement is the condition
itself (in which case the condition was returned anyway), or the rightmost
leaf is returned; for correctness, the rightmost leaf must be evaluated anyway
(which the CFG does in the last statement), thus we can just return the last
statement in that case, too. Added an assert to verify the invariant.
llvm-svn: 207957
a std::vector that allocates on the heap. As a consequence, we have to
run all of their destructors when tearing down the set, not just
deallocate the memory blobs.
llvm-svn: 207902
While we don't model pointer-to-member operators yet (neither .* nor ->*),
CallAndMessageChecker still checks to make sure the 'this' object is not
null or undefined first. However, it also expects that the object should
always have a valid MemRegion, something that's generally important elsewhere
in the analyzer as well. Ensure this is true ahead of time, just like we do
for member access.
PR19531
llvm-svn: 207561
definition below all of the header #include lines, clang edition.
If you want more details about this, you can see some of the commits to
Debug.h in LLVM recently. This is just the clang section of a cleanup
I've done for all uses of DEBUG_TYPE in LLVM.
llvm-svn: 206849
This also includes some infrastructure to make it easier to build multi-argument
selectors, rather than trying to use string matching on each piece. There's a bit
more setup code, but less cost at runtime.
PR18908
llvm-svn: 205827
Fixes a false positive when temporary destructors are enabled where a temporary
is destroyed after a variable is constructed but before the VarDecl itself is
processed, which occurs when the variable is in the condition of an if or while.
Patch by Alex McCarthy, with an extra test from me.
llvm-svn: 205661
If we're trying to get the zero element region of something that's not a region,
we should be returning UnknownVal, which is what ProgramState::getLValue will
do for us.
Patch by Alex McCarthy!
llvm-svn: 205327
Add M_ZERO awareness to malloc() static analysis in Clang for FreeBSD,
NetBSD, and OpenBSD in a similar fashion to O_CREAT for open(2).
These systems have a three-argument malloc() in the kernel where the
third argument contains flags; the M_ZERO flag will zero-initialize the
allocated buffer.
This should reduce the number of false positives when running static
analysis on BSD kernels.
Additionally, add kmalloc() (Linux kernel malloc()) and treat __GFP_ZERO
like M_ZERO on Linux.
Future work involves a better method of checking for named flags without
hardcoding values.
Patch by Conrad Meyer, with minor modifications by me.
llvm-svn: 204832
A refinement of r198953 to handle cases where an object is accessed both through
a property getter and through direct ivar access. An object accessed through a
property should always be treated as +0, i.e. not owned by the caller. However,
an object accessed through an ivar may be at +0 or at +1, depending on whether
the ivar is a strong reference. Outside of ARC, we don't have that information,
so we just don't track objects accessed through ivars.
With this change, accessing an ivar directly will deliberately override the +0
provided by a getter, but only if the +0 hasn't participated in other retain
counting yet. That isn't perfect, but it's already unusual for people to be
mixing property access with direct ivar access. (The primary use case for this
is in setters, init methods, and -dealloc.)
Thanks to Ted for spotting a few mistakes in private review.
<rdar://problem/16333368>
llvm-svn: 204730
David Blaikie