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
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
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 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
a comma separated collection of key:value pairs (which are strings). This
allows a general way to provide analyzer configuration data from the command line.
No clients yet.
llvm-svn: 162827
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
The analyzer gives up path exploration under certain conditions. For
example, when the same basic block has been visited more than 4 times.
With inlining turned on, this could lead to decrease in code coverage.
Specifically, if we give up inside the inlined function, the rest of
parent's basic blocks will not get analyzed.
This commit introduces an option to enable re-run along the failed path,
in which we do not inline the last inlined call site. This is done by
enqueueing the node before the processing of the inlined call site
with a special policy encoded in the state. The policy tells us not to
inline the call site along the path.
This lead to ~10% increase in the number of paths analyzed. Even though
we expected a much greater coverage improvement.
The option is turned off by default for now.
llvm-svn: 153534
command line options for inlining tuning.
This adds the option for stack depth bound as well as function size
bound.
+ minor doxygenification
llvm-svn: 151930
This seems to negatively affect compile time onsome ObjC tests
(which use a lot of partial diagnostics I assume). I have to come
up with a way to keep them inline without including Diagnostic.h
everywhere. Now adding a new diagnostic requires a full rebuild
of e.g. the static analyzer which doesn't even use those diagnostics.
This reverts commit 6496bd10dc3a6d5e3266348f08b6e35f8184bc99.
This reverts commit 7af19b817ba964ac560b50c1ed6183235f699789.
This reverts commit fdd15602a42bbe26185978ef1e17019f6d969aa7.
This reverts commit 00bd44d5677783527d7517c1ffe45e4d75a0f56f.
This reverts commit ef9b60ffed980864a8db26ad30344be429e58ff5.
llvm-svn: 150006
Fix all the files that depended on transitive includes of Diagnostic.h.
With this patch in place changing a diagnostic no longer requires a full rebuild of the StaticAnalyzer.
llvm-svn: 149781
The motivation of this large change is to drastically simplify the logic in ExprEngine going forward.
Some fallout is that the output of some BugReporterVisitors is not as accurate as before; those will
need to be fixed over time. There is also some possible performance regression as RemoveDeadBindings
will be called frequently; this can also be improved over time.
llvm-svn: 136419
Eventually there will also be a lib/StaticAnalyzer/Frontend that will handle initialization and checker registration.
Yet another library to avoid cyclic dependencies between Core and Checkers.
llvm-svn: 125124
Ted Kremenek