Accidentally commited earlier with the same commit title, but really it
should've been
"Revert rC349283 '[analyzer][MallocChecker] Improve warning messages on double-delete errors'"
llvm-svn: 349344
Re-using a moved-from local variable is most likely a bug because there's
rarely a good motivation for not introducing a separate variable instead.
We plan to keep emitting such warnings by default.
Introduce a flag that allows disabling warnings on local variables that are
not of a known move-unsafe type. If it doesn't work out as we expected,
we'll just flip the flag.
We still warn on move-unsafe objects and unsafe operations on known move-safe
objects.
Differential Revision: https://reviews.llvm.org/D55730
llvm-svn: 349327
This re-applies commit r349226 that was reverted in r349233 due to failures
on clang-x64-windows-msvc.
Specify enum type as unsigned for use in bit field. Otherwise overflows
may cause UB.
Differential Revision: https://reviews.llvm.org/D55388
llvm-svn: 349326
StaticAnalyzer uses the CFG-based RelaxedLiveVariables analysis in order to,
in particular, figure out values of which expressions are still needed.
When the expression becomes "dead", it is garbage-collected during
the dead binding scan.
Expressions that constitute branches/bodies of control flow statements,
eg. `E1' in `if (C1) E1;' but not `E2' in `if (C2) { E2; }', were kept alive
for too long. This caused false positives in MoveChecker because it relies
on cleaning up loop-local variables when they go out of scope, but some of those
live-for-too-long expressions were keeping a reference to those variables.
Fix liveness analysis to correctly mark these expressions as dead.
Add a debug checker, debug.DumpLiveStmts, in order to test expressions liveness.
Differential Revision: https://reviews.llvm.org/D55566
llvm-svn: 349320
This patch merely reorganizes some things, and features no functional change.
In detail:
* Provided documentation, or moved existing documentation in more obvious
places.
* Added dividers. (the //===----------===// thing).
* Moved getAllocationFamily, printAllocDeallocName, printExpectedAllocName and
printExpectedDeallocName in the global namespace on top of the file where
AllocationFamily is declared, as they are very strongly related.
* Moved isReleased and MallocUpdateRefState near RefState's definition for the
same reason.
* Realloc modeling was very poor in terms of variable and structure naming, as
well as documentation, so I renamed some of them and added much needed docs.
* Moved function IdentifierInfos to a separate struct, and moved isMemFunction,
isCMemFunction adn isStandardNewDelete inside it. This makes the patch affect
quite a lot of lines, should I extract it to a separate one?
* Moved MallocBugVisitor out of MallocChecker.
* Preferred switches to long else-if branches in some places.
* Neatly organized some RUN: lines.
Differential Revision: https://reviews.llvm.org/D54823
llvm-svn: 349281
Now that CheckerRegistry lies in Frontend, we can finally eliminate
ClangCheckerRegistry. Fortunately, this also provides us with a
DiagnosticsEngine, so I went ahead and removed some parameters from it's
methods.
Differential Revision: https://reviews.llvm.org/D54437
llvm-svn: 349280
ClangCheckerRegistry is a very non-obvious, poorly documented, weird concept.
It derives from CheckerRegistry, and is placed in lib/StaticAnalyzer/Frontend,
whereas it's base is located in lib/StaticAnalyzer/Core. It was, from what I can
imagine, used to circumvent the problem that the registry functions of the
checkers are located in the clangStaticAnalyzerCheckers library, but that
library depends on clangStaticAnalyzerCore. However, clangStaticAnalyzerFrontend
depends on both of those libraries.
One can make the observation however, that CheckerRegistry has no place in Core,
it isn't used there at all! The only place where it is used is Frontend, which
is where it ultimately belongs.
This move implies that since
include/clang/StaticAnalyzer/Checkers/ClangCheckers.h only contained a single function:
class CheckerRegistry;
void registerBuiltinCheckers(CheckerRegistry ®istry);
it had to re purposed, as CheckerRegistry is no longer available to
clangStaticAnalyzerCheckers. It was renamed to BuiltinCheckerRegistration.h,
which actually describes it a lot better -- it does not contain the registration
functions for checkers, but only those generated by the tblgen files.
Differential Revision: https://reviews.llvm.org/D54436
llvm-svn: 349275
Renaming collectCheckers to getEnabledCheckers
Changing the functionality to acquire all enabled checkers, rather then collect
checkers for a specific CheckerOptInfo (for example, collecting all checkers for
{ "core", true }, which meant enabling all checkers from the core package, which
was an unnecessary complication).
Removing CheckerOptInfo, instead of storing whether the option was claimed via a
field, we handle errors immediately, as getEnabledCheckers can now access a
DiagnosticsEngine. Realize that the remaining information it stored is directly
accessible through AnalyzerOptions.CheckerControlList.
Fix a test with -analyzer-disable-checker -verify accidentally left in.
llvm-svn: 349274
Right now they report to have one parameter with null decl,
because initializing an ArrayRef of pointers with a nullptr
yields an ArrayRef to an array of one null pointer.
Fixes a crash in the OSObject section of RetainCountChecker.
Differential Revision: https://reviews.llvm.org/D55671
llvm-svn: 349229
The checker wasn't prepared to see the dealloc message sent to the class itself
rather than to an instance, as if it was +dealloc.
Additionally, it wasn't prepared for pure-unknown or undefined self values.
The new guard covers that as well, but it is annoying to test because
both kinds of values shouldn't really appear and we generally want to
get rid of all of them (by modeling unknown values with symbols and
by warning on use of undefined values before they are used).
The CHECK: directive for FileCheck at the end of the test looks useless,
so i removed it.
Differential Revision: https://reviews.llvm.org/D55680
llvm-svn: 349228
Use trackExpressionValue() (previously known as trackNullOrUndefValue())
to track index value in the report, so that the user knew
what Static Analyzer thinks the index is.
Additionally, implement printState() to help debugging the checker later.
Differential Revision: https://reviews.llvm.org/D55458
llvm-svn: 349227
Calling operator*() or operator->() on a null STL smart pointer is
undefined behavior.
Smart pointers are specified to become null after being moved from.
So we can't warn on arbitrary method calls, but these two operators
definitely make no sense.
The new bug is fatal because it's an immediate UB,
unlike other use-after-move bugs.
The work on a more generic null smart pointer dereference checker
is still pending.
Differential Revision: https://reviews.llvm.org/D55388
llvm-svn: 349226
Some C++ standard library classes provide additional guarantees about their
state after move. Suppress warnings on such classes until a more precise
behavior is implemented. Warnings for locals are not suppressed anyway
because it's still most likely a bug.
Differential Revision: https://reviews.llvm.org/D55307
llvm-svn: 349191
If a moved-from object is passed into a conservatively evaluated function
by pointer or by reference, we assume that the function may reset its state.
Make sure it doesn't apply to const pointers and const references. Add a test
that demonstrates that it does apply to rvalue references.
Additionally, make sure that the object is invalidated when its contents change
for reasons other than invalidation caused by evaluating a call conservatively.
In particular, when the object's fields are manipulated directly, we should
assume that some sort of reset may be happening.
Differential Revision: https://reviews.llvm.org/D55289
llvm-svn: 349190
Functional changes include:
* The run.files property is now an array instead of a mapping.
* fileLocation objects now have a fileIndex property specifying the array index into run.files.
* The resource.rules property is now an array instead of a mapping.
* The result object was given a ruleIndex property that is an index into the resource.rules array.
* rule objects now have their "id" field filled out in addition to the name field.
* Updated the schema and spec version numbers to 11-28.
llvm-svn: 349188
- explicit_bzero has limited scope/usage only for security/crypto purposes but is non-optimisable version of memset/0 and bzero.
- explicit_memset has similar signature and semantics as memset but is also a non-optimisable version.
Reviewers: NoQ
Reviewed By: NoQ
Differential Revision: https://reviews.llvm.org/D54592
llvm-svn: 348884
Memoization dose not seem to be necessary, as other statement visitors
run just fine without it,
and in fact seems to be causing memory corruptions.
Just removing it instead of investigating the root cause.
rdar://45945002
Differential Revision: https://reviews.llvm.org/D54921
llvm-svn: 348822
This is currently a diagnostics, but might be upgraded to an error in the future,
especially if we introduce os_return_on_success attributes.
rdar://46359592
Differential Revision: https://reviews.llvm.org/D55530
llvm-svn: 348820
Escaping to void * / uint64_t / others non-OSObject * should stop tracking,
as such functions can have heterogeneous semantics depending on context,
and can not always be annotated.
rdar://46439133
Differential Revision: https://reviews.llvm.org/D55465
llvm-svn: 348675
Allow enabling and disabling tracking of ObjC/CF objects
separately from tracking of OS objects.
Differential Revision: https://reviews.llvm.org/D55400
llvm-svn: 348638
The option has no tests, is not used anywhere, and is actually
incorrect: it prints the line number without the reference to a file,
which can be outright incorrect.
Differential Revision: https://reviews.llvm.org/D55385
llvm-svn: 348637
Summary:
With a new switch we may be able to print to stderr if a new TU is being loaded
during CTU. This is very important for higher level scripts (like CodeChecker)
to be able to parse this output so they can create e.g. a zip file in case of
a Clang crash which contains all the related TU files.
Reviewers: xazax.hun, Szelethus, a_sidorin, george.karpenkov
Subscribers: whisperity, baloghadamsoftware, szepet, rnkovacs, a.sidorin, mikhail.ramalho, donat.nagy, dkrupp,
Differential Revision: https://reviews.llvm.org/D55135
llvm-svn: 348594
Previously, the iterator range checker only warned upon dereferencing of
iterators outside their valid range as well as increments and decrements of
out-of-range iterators where the result remains out-of-range. However, the C++
standard is more strict than this: decrementing begin() or incrementing end()
results in undefined behaviour even if the iterator is not dereferenced
afterwards. Coming back to the range once out-of-range is also undefined.
This patch corrects the behaviour of the iterator range checker: warnings are
given for any operation whose result is ahead of begin() or past the end()
(which is the past-end iterator itself, thus now we are speaking of past
past-the-end).
Differential Revision: https://reviews.llvm.org/D53812
llvm-svn: 348245
If an iterator is represented by a derived C++ class but its comparison operator
is for its base the iterator checkers cannot recognize the iterators compared.
This results in false positives in very straightforward cases (range error when
dereferencing an iterator after disclosing that it is equal to the past-the-end
iterator).
To overcome this problem we always use the region of the topmost base class for
iterators stored in a region. A new method called getMostDerivedObjectRegion()
was added to the MemRegion class to get this region.
Differential Revision: https://reviews.llvm.org/D54466
llvm-svn: 348244
Includes "resize" and "shrink" because they can reset the object to a known
state in certain circumstances.
Differential Revision: https://reviews.llvm.org/D54563
llvm-svn: 348235
The warning piece traditionally describes the bug itself, i.e.
"The bug is a _____", eg. "Attempt to delete released memory",
"Resource leak", "Method call on a moved-from object".
Event pieces produced by the visitor are usually in a present tense, i.e.
"At this moment _____": "Memory is released", "File is closed",
"Object is moved".
Additionally, type information is added into the event pieces for STL objects
(in order to highlight that it is in fact an STL object), and the respective
event piece now mentions that the object is left in an unspecified state
after it was moved, which is a vital piece of information to understand the bug.
Differential Revision: https://reviews.llvm.org/D54560
llvm-svn: 348229
In general case there use-after-move is not a bug. It depends on how the
move-constructor or move-assignment is implemented.
In STL, the convention that applies to most classes is that the move-constructor
(-assignment) leaves an object in a "valid but unspecified" state. Using such
object without resetting it to a known state first is likely a bug. Objects
Local value-type variables are special because due to their automatic lifetime
there is no intention to reuse space. If you want a fresh object, you might
as well make a new variable, no need to move from a variable and than re-use it.
Therefore, it is not always a bug, but it is obviously easy to suppress when it
isn't, and in most cases it indeed is - as there's no valid intention behind
the intentional use of a local after move.
This applies not only to local variables but also to parameter variables,
not only of value type but also of rvalue reference type (but not to lvalue
references).
Differential Revision: https://reviews.llvm.org/D54557
llvm-svn: 348210
The checker had extra code to clean up memory regions that were sticking around
in the checker without ever being cleaned up due to the bug that was fixed in
r347953. Because of that, if a region was moved from, then became dead,
and then reincarnated, there were false positives.
Why regions are even allowed to reincarnate is a separate story. Luckily, this
only happens for local regions that don't produce symbols when loaded from.
No functional change intended. The newly added test demonstrates that even
though no cleanup is necessary upon destructor calls, the early return
cannot be removed. It was not failing before the patch.
Differential Revision: https://reviews.llvm.org/D54372
llvm-svn: 348208
This follows the Static Analyzer's tradition to name checkers after
things in which they find bugs, not after bugs they find.
Differential Revision: https://reviews.llvm.org/D54556
llvm-svn: 348201
This continues the work that was started in r342313, which now gets applied to
object-under-construction tracking in C++. Makes it possible to debug
temporaries by dumping exploded graphs again.
Differential Revision: https://reviews.llvm.org/D54459
llvm-svn: 348200
Buildbot failures were caused by an unrelated UB that was introduced in r347943
and fixed in r347970.
Also the revision was incorrectly specified as r344580 during revert.
Differential Revision: https://reviews.llvm.org/D54017
llvm-svn: 348188
It seems the two failing tests can be simply fixed after r348037
Fix 3 cases in Analysis/builtin-functions.cpp
Delete the bad CodeGen/builtin-constant-p.c for now
llvm-svn: 348053
Kept the "indirect_builtin_constant_p" test case in test/SemaCXX/constant-expression-cxx1y.cpp
while we are investigating why the following snippet fails:
extern char extern_var;
struct { int a; } a = {__builtin_constant_p(extern_var)};
llvm-svn: 348039
In earlier patches regarding AnalyzerOptions, a lot of effort went into
gathering all config options, and changing the interface so that potential
misuse can be eliminited.
Up until this point, AnalyzerOptions only evaluated an option when it was
querried. For example, if we had a "-no-false-positives" flag, AnalyzerOptions
would store an Optional field for it that would be None up until somewhere in
the code until the flag's getter function is called.
However, now that we're confident that we've gathered all configs, we can
evaluate off of them before analysis, so we can emit a error on invalid input
even if that prticular flag will not matter in that particular run of the
analyzer. Another very big benefit of this is that debug.ConfigDumper will now
show the value of all configs every single time.
Also, almost all options related class have a similar interface, so uniformity
is also a benefit.
The implementation for errors on invalid input will be commited shorty.
Differential Revision: https://reviews.llvm.org/D53692
llvm-svn: 348031
Artem Dergachev