Commit Graph

38 Commits

Author SHA1 Message Date
Craig Topper 0dbb783c7b [C++11] Use 'nullptr'. StaticAnalyzer edition.
llvm-svn: 209642
2014-05-27 02:45:47 +00:00
Reid Kleckner 588c937228 Use llvm::DeleteContainerSeconds when possible
llvm-svn: 201739
2014-02-19 23:44:52 +00:00
Jordan Rose acd080b956 [analyzer] Add support for testing the presence of weak functions.
When casting the address of a FunctionTextRegion to bool, or when adding
constraints to such an address, use a stand-in symbol to represent the
presence or absence of the function if the function is weakly linked.
This is groundwork for possible simple availability testing checks, and
can already catch mistakes involving inverted null checks for
weakly-linked functions.

Currently, the implementation reuses the "extent" symbols, originally created
for tracking the size of a malloc region. Since FunctionTextRegions cannot
be dereferenced, the extent symbol will never be used for anything else.
Still, this probably deserves a refactoring in the future.

This patch does not attempt to support testing the presence of weak
/variables/ (global variables), which would likely require much more of
a change and a generalization of "region structure metadata", like the
current "extents", vs. "region contents metadata", like CStringChecker's
"string length".

Patch by Richard <tarka.t.otter@googlemail.com>!

llvm-svn: 189492
2013-08-28 17:07:04 +00:00
Robert Wilhelm 25284cc95b Use pop_back_val() instead of both back() and pop_back().
No functionality change intended.

llvm-svn: 189112
2013-08-23 16:11:15 +00:00
Jordan Rose 61e221f68d [analyzer] Replace isIntegerType() with isIntegerOrEnumerationType().
Previously, the analyzer used isIntegerType() everywhere, which uses the C
definition of "integer". The C++ predicate with the same behavior is
isIntegerOrUnscopedEnumerationType().

However, the analyzer is /really/ using this to ask if it's some sort of
"integrally representable" type, i.e. it should include C++11 scoped
enumerations as well. hasIntegerRepresentation() sounds like the right
predicate, but that includes vectors, which the analyzer represents by its
elements.

This commit audits all uses of isIntegerType() and replaces them with the
general isIntegerOrEnumerationType(), except in some specific cases where
it makes sense to exclude scoped enumerations, or any enumerations. These
cases now use isIntegerOrUnscopedEnumerationType() and getAs<BuiltinType>()
plus BuiltinType::isInteger().

isIntegerType() is hereby banned in the analyzer - lib/StaticAnalysis and
include/clang/StaticAnalysis. :-)

Fixes real assertion failures. PR15703 / <rdar://problem/12350701>

llvm-svn: 179081
2013-04-09 02:30:33 +00:00
Anna Zaks bda130f02a [analyzer] Use isLiveRegion to determine when SymbolRegionValue is dead.
Fixes a FIXME, improves dead symbol collection, suppresses a false positive,
which resulted from reusing the same symbol twice for simulation of 2 calls to the same function.

Fixing this lead to 2 possible false negatives in CString checker. Since the checker is still alpha and
the solution will not require revert of this commit, move the tests to a FIXME section.

llvm-svn: 177206
2013-03-15 23:34:29 +00:00
Jordan Rose 06f68eda4d [analyzer] Include opcode in dumping a SymSymExpr.
For debugging use only; no functionality change.

llvm-svn: 177187
2013-03-15 21:41:50 +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
Ted Kremenek a808e165b2 Remove unnecessary ASTContext& parameter from SymExpr::getType().
llvm-svn: 164661
2012-09-26 06:00:14 +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
Jordan Rose 60d704ab4a [analyzer] Calculate liveness for symbolic exprs as well as atomic symbols.
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
2012-09-25 19:03:01 +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
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 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 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
Richard Smith 802c4b7015 Fix undefined behavior: member function calls where 'this' is a null pointer.
llvm-svn: 162430
2012-08-23 06:16:52 +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
Anna Zaks 1d3d51a6e6 [analyzer] Add a complexity bound on history tracking.
(Currently, this is only relevant for tainted data.)

llvm-svn: 156050
2012-05-03 02:13:50 +00:00
Anna Zaks 7e53bd6fb0 [analyzer] Run remove dead bindings right before leaving a function.
This is needed to ensure that we always report issues in the correct
function. For example, leaks are identified when we call remove dead
bindings. In order to make sure we report a callee's leak in the callee,
we have to run the operation in the callee's context.

This change required quite a bit of infrastructure work since:
 - We used to only run remove dead bindings before a given statement;
here we need to run it after the last statement in the function. For
this, we added additional Program Point and special mode in the
SymbolReaper to remove all symbols in context lower than the current
one.
 - The call exit operation turned into a sequence of nodes, which are
now guarded by CallExitBegin and CallExitEnd nodes for clarity and
convenience.

(Sorry for the long diff.)

llvm-svn: 155244
2012-04-20 21:59:08 +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
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
David Blaikie 68e081d606 Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch
llvm-svn: 146959
2011-12-20 02:48:34 +00:00
Anna Zaks ecd730085d [analyzer] Introduce IntSymExpr, where the integer is on the lhs.
Fix a bug in SimpleSValBuilder, where we should swap lhs and rhs when calling generateUnknownVal(), - the function which creates symbolic expressions when data is tainted. The issue is not visible when we only create the expressions for taint since all expressions are commutative from taint perspective.

Refactor SymExpr::symbol_iterator::expand() to use a switch instead of a chain of ifs.

llvm-svn: 146336
2011-12-10 23:36:51 +00:00
Anna Zaks ee1a43533b [analyzer] Refactor: Move symbol_iterator from SVal to SymExpr, use it
for finding dependent symbols for taint.

llvm-svn: 145986
2011-12-06 23:12:33 +00:00
Anna Zaks c25efccc8b [analyzer] Propagate taint through NonLoc to NonLoc casts.
- Created a new SymExpr type - SymbolCast.
 - SymbolCast is created when we don't know how to simplify a NonLoc to
NonLoc casts.
 - A bit of code refactoring: introduced dispatchCast to have better
code reuse, remove a goto.
 - Updated the test case to showcase the new taint flow.

llvm-svn: 145985
2011-12-06 23:12:27 +00:00
Ted Kremenek dccc2b2277 Remove AnalysisContext::getLiveVariables(), and introduce a templatized mechanism to lazily create analyses that are attached to AnalysisContext objects.
llvm-svn: 141425
2011-10-07 22:21:02 +00:00
David Blaikie aa347f9392 Removing a bunch of dead returns/breaks after llvm_unreachables.
llvm-svn: 140407
2011-09-23 20:26:49 +00:00
David Blaikie 83d382b1ca Switch assert(0/false) llvm_unreachable.
llvm-svn: 140367
2011-09-23 05:06:16 +00:00
Ted Kremenek 5ef32dbf2a Cleanup various declarations of 'Stmt*' to be 'Stmt *', etc. in libAnalyzer and libStaticAnalyzer[*]. It was highly inconsistent, and very ugly to look at.
llvm-svn: 137537
2011-08-12 23:37:29 +00:00
Ted Kremenek 8df44b2632 [analyzer] Introduce new MemRegion, "TypedValueRegion", so that we can separate TypedRegions that implement getValueType() from those that don't.
Patch by Olaf Krzikalla!

llvm-svn: 137498
2011-08-12 20:02:48 +00:00
Anna Zaks 9b25cee36f Optimizations for Dependent Symbol tracking (as per Ted's code review for r137309):
1) Change SymbolDependTy map to keep pointers as data. And other small tweaks like making the DenseMap smaller 64->16 elements; remove removeSymbolDependencies() as it will probably not be used.

2) Do not mark dependents live more then once.

llvm-svn: 137401
2011-08-12 00:34:56 +00:00
Anna Zaks 22a9d0f316 Analyzer Core: Adding support for user-defined symbol dependencies. (For example, the allocated resource symbol only needs to be freed if no error has been returned by the allocator, so a checker might want to make the lifespan of the error code symbol depend on the allocated resource symbol.) Note, by default, the map that holds the dependencies will get destroyed along with the SymbolManager at the end of function exploration.
llvm-svn: 137309
2011-08-11 16:43:28 +00:00
Ted Kremenek c91ca30b4c [analyzer] Change SymbolReaper to store region roots implied by the Environment, allowing it be queried when
determining if symbols derived from regions are still live.

llvm-svn: 137005
2011-08-06 00:29:57 +00:00
Ted Kremenek e9fda1e48a [analyzer] Overhaul how the static analyzer expects CFGs by forcing CFGs to be linearized only when used by the static analyzer. This required a rewrite of LiveVariables, and exposed a ton of subtle bugs.
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
2011-07-28 23:07:59 +00:00
Chris Lattner 0e62c1cc0b remove unneeded llvm:: namespace qualifiers on some core types now that LLVM.h imports
them into the clang namespace.

llvm-svn: 135852
2011-07-23 10:55:15 +00:00
Zhanyong Wan 85a203ebdd Makes most methods in SVals.h conform to the naming guide. Reviewed
by kremenek.

llvm-svn: 125687
2011-02-16 21:13:32 +00:00
Ted Kremenek f8cbac4b91 Split 'include/clang/StaticAnalyzer' into 'include/clang/StaticAnalyzer/Core' and 'include/clang/StaticAnalyzer/Checkers'.
This layout matches lib/StaticAnalyzer, which corresponds to two StaticAnalyzer libraries.

llvm-svn: 125251
2011-02-10 01:03:03 +00:00
Argyrios Kyrtzidis fa0734ec4f [analyzer] Move the files in lib/StaticAnalyzer to lib/StaticAnalyzer/Core.
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
2011-02-08 22:30:36 +00:00