`OS << ND->getDeclName();` is equivalent to `OS << ND->getNameAsString();`
without the extra temporary string.
This is not quite a NFC since two uses of `getNameAsString` in a
diagnostic are replaced, which results in the named entity being
quoted with additional "'"s (ie: 'var' instead of var).
https://bugs.llvm.org/show_bug.cgi?id=46253
This is an obvious hack because realloc isn't any more affected than other
functions modeled by MallocChecker (or any user of CallDescription really),
but the nice solution will take some time to implement.
Differential Revision: https://reviews.llvm.org/D81745
In the added testfile, the from argument was recognized as
&Element{SymRegion{reg_$0<long * global_a>},-1 S64b,long}
instead of
reg_$0<long * global_a>.
If you remember the mail [1] I sent out about how I envision the future of the
already existing checkers to look dependencywise, one my main points was that no
checker that emits diagnostics should be a dependency. This is more problematic
for some checkers (ahem, RetainCount [2]) more than for others, like this one.
The MallocChecker family is a mostly big monolithic modeling class some small
reporting checkers that only come to action when we are constructing a warning
message, after the actual bug was detected. The implication of this is that
NewDeleteChecker doesn't really do anything to depend on, so this change was
relatively simple.
The only thing that complicates this change is that FreeMemAux (MallocCheckers
method that models general memory deallocation) returns after calling a bug
reporting method, regardless whether the report was ever emitted (which may not
always happen, for instance, if the checker responsible for the report isn't
enabled). This return unfortunately happens before cleaning up the maps in the
GDM keeping track of the state of symbols (whether they are released, whether
that release was successful, etc). What this means is that upon disabling some
checkers, we would never clean up the map and that could've lead to false
positives, e.g.:
error: 'warning' diagnostics seen but not expected:
File clang/test/Analysis/NewDelete-intersections.mm Line 66: Potential leak of memory pointed to by 'p'
File clang/test/Analysis/NewDelete-intersections.mm Line 73: Potential leak of memory pointed to by 'p'
File clang/test/Analysis/NewDelete-intersections.mm Line 77: Potential leak of memory pointed to by 'p'
error: 'warning' diagnostics seen but not expected:
File clang/test/Analysis/NewDelete-checker-test.cpp Line 111: Undefined or garbage value returned to caller
File clang/test/Analysis/NewDelete-checker-test.cpp Line 200: Potential leak of memory pointed to by 'p'
error: 'warning' diagnostics seen but not expected:
File clang/test/Analysis/new.cpp Line 137: Potential leak of memory pointed to by 'x'
There two possible approaches I had in mind:
Make bug reporting methods of MallocChecker returns whether they succeeded, and
proceed with the rest of FreeMemAux if not,
Halt execution with a sink node upon failure. I decided to go with this, as
described in the code.
As you can see from the removed/changed test files, before the big checker
dependency effort landed, there were tests to check for all the weird
configurations of enabled/disabled checkers and their messy interactions, I
largely repurposed these.
[1] http://lists.llvm.org/pipermail/cfe-dev/2019-August/063070.html
[2] http://lists.llvm.org/pipermail/cfe-dev/2019-August/063205.html
Differential Revision: https://reviews.llvm.org/D77474
Exactly what it says on the tin! This is clearly not the end of the road in this
direction, the parameters could be merged far more with the use of CallEvent or
a better value type in the CallDescriptionMap, but this was shockingly difficult
enough on its own. I expect that simplifying the file further will be far easier
moving forward.
The end goal is to research how we could create a more mature checker
interaction infrastructure for more complicated C++ modeling, and I'm pretty
sure that being able successfully split up our giants is the first step in this
direction.
Differential Revision: https://reviews.llvm.org/D75432
Party based on this thread:
http://lists.llvm.org/pipermail/cfe-dev/2020-February/064754.html.
This patch merges two of CXXAllocatorCall's parameters, so that we are able to
supply a CallEvent object to check::NewAllocatorCall (see the description of
D75430 to see why this would be great).
One of the things mentioned by @NoQ was the following:
I think at this point we might actually do a good job sorting out this
check::NewAllocator issue because we have a "separate" "Environment" to hold
the other SVal, which is "objects under construction"! - so we should probably
simply teach CXXAllocatorCall to extract the value from the
objects-under-construction trait of the program state and we're good.
I had MallocChecker in my crosshair for now, so I admittedly threw together
something as a proof of concept. Now that I know that this effort is worth
pursuing though, I'll happily look for a solution better then demonstrated in
this patch.
Differential Revision: https://reviews.llvm.org/D75431
The very essence of MallocChecker lies in 2 overload sets: the FreeMemAux
functions and the MallocMemAux functions. The former houses most of the error
checking as well (aside from leaks), such as incorrect deallocation. There, we
check whether the argument's MemSpaceRegion is the heap or unknown, and if it
isn't, we know we encountered a bug (aside from a corner case patched by
@balazske in D76830), as specified by MEM34-C.
In ReallocMemAux, which really is the combination of FreeMemAux and
MallocMemAux, we incorrectly early returned if the memory argument of realloc is
non-symbolic. The problem is, one of the cases where this happens when we know
precisely what the region is, like an array, as demonstrated in the test file.
So, lets get rid of this false negative :^)
Side note, I dislike the warning message and the associated checker name, but
I'll address it in a later patch.
Differential Revision: https://reviews.llvm.org/D79415
One of the pain points in simplifying MallocCheckers interface by gradually
changing to CallEvent is that a variety of C++ allocation and deallocation
functionalities are modeled through preStmt<...> where CallEvent is unavailable,
and a single one of these callbacks can prevent a mass parameter change.
This patch introduces a new CallEvent, CXXDeallocatorCall, which happens after
preStmt<CXXDeleteExpr>, and can completely replace that callback as
demonstrated.
Differential Revision: https://reviews.llvm.org/D75430
Since its important to know whether a function frees memory (even if its a
reallocating function!), I used two CallDescriptionMaps to merge all
CallDescriptions into it. MemFunctionInfoTy no longer makes sense, it may never
have, but for now, it would be more of a distraction then anything else.
Differential Revision: https://reviews.llvm.org/D68165
Summary:
The kernel kmalloc function may return a constant value ZERO_SIZE_PTR
if a zero-sized block is allocated. This special value is allowed to
be passed to kfree and should produce no warning.
This is a simple version but should be no problem. The macro is always
detected independent of if this is a kernel source code or any other
code.
Reviewers: Szelethus, martong
Reviewed By: Szelethus, martong
Subscribers: rnkovacs, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, gamesh411, Charusso, martong, ASDenysPetrov, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76830
Some checkers may not only depend on language options but also analyzer options.
To make this possible this patch changes the parameter of the shouldRegister*
function to CheckerManager to be able to query the analyzer options when
deciding whether the checker should be registered.
Differential Revision: https://reviews.llvm.org/D75271
Exactly what it says on the tin! I decided not to merge this with the patch that
changes all these to a CallDescriptionMap object, so the patch is that much more
trivial.
Differential Revision: https://reviews.llvm.org/D68163
The following series of refactoring patches aim to fix the horrible mess that MallocChecker.cpp is.
I genuinely hate this file. It goes completely against how most of the checkers
are implemented, its by far the biggest headache regarding checker dependencies,
checker options, or anything you can imagine. On top of all that, its just bad
code. Its seriously everything that you shouldn't do in C++, or any other
language really. Bad variable/class names, in/out parameters... Apologies, rant
over.
So: there are a variety of memory manipulating function this checker models. One
aspect of these functions is their AllocationFamily, which we use to distinguish
between allocation kinds, like using free() on an object allocated by operator
new. However, since we always know which function we're actually modeling, in
fact we know it compile time, there is no need to use tricks to retrieve this
information out of thin air n+1 function calls down the line. This patch changes
many methods of MallocChecker to take a non-optional AllocationFamily template
parameter (which also makes stack dumps a bit nicer!), and removes some no
longer needed auxiliary functions.
Differential Revision: https://reviews.llvm.org/D68162
Summary:
This patch introduces a placeholder for representing the dynamic size of
regions. It also moves the `getExtent()` method of `SubRegions` to the
`MemRegionManager` as `getStaticSize()`.
Reviewed By: NoQ
Differential Revision: https://reviews.llvm.org/D69540
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
MallocChecker warns when memory is passed into -[NSData initWithBytesNoCopy]
but isn't allocated by malloc(), because it will be deallocated by free().
However, initWithBytesNoCopy has an overload that takes an arbitrary block
for deallocating the object. If such overload is used, it is no longer
necessary to make sure that the memory is allocated by malloc().
Traditionally, clang-tidy uses the term check, and the analyzer uses checker,
but in the very early years, this wasn't the case, and code originating from the
early 2010's still incorrectly refer to checkers as checks.
This patch attempts to hunt down most of these, aiming to refer to checkers as
checkers, but preserve references to callback functions (like checkPreCall) as
checks.
Differential Revision: https://reviews.llvm.org/D67140
llvm-svn: 371760
These static functions deal with ExplodedNodes which is something we don't want
the PathDiagnostic interface to know anything about, as it's planned to be
moved out of libStaticAnalyzerCore.
Differential Revision: https://reviews.llvm.org/D67382
llvm-svn: 371659
That's one of the few random entities in the PathDiagnostic interface that
are specific to the Static Analyzer. By moving them out we could let
everybody use path diagnostics without linking against Static Analyzer.
Differential Revision: https://reviews.llvm.org/D67381
llvm-svn: 371658
Checkers are now required to specify whether they're creating a
path-sensitive report or a path-insensitive report by constructing an
object of the respective type.
This makes BugReporter more independent from the rest of the Static Analyzer
because all Analyzer-specific code is now in sub-classes.
Differential Revision: https://reviews.llvm.org/D66572
llvm-svn: 371450
Write tests for the actual crash that was found. Write comments and refactor
code around 17 style bugs and suppress 3 false positives.
Differential Revision: https://reviews.llvm.org/D66847
llvm-svn: 370246
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368942
When I'm new to a file/codebase, I personally find C++'s strong static type
system to be a great aid. BugReporter.cpp is still painful to read however:
function calls are made with mile long parameter lists, seemingly all of them
taken with a non-const reference/pointer. This patch fixes nothing but this:
make a few things const, and hammer it until it compiles.
Differential Revision: https://reviews.llvm.org/D65382
llvm-svn: 368735
find clang/ -type f -exec sed -i 's/std::shared_ptr<PathDiagnosticPiece>/PathDiagnosticPieceRef/g' {} \;
git diff -U3 --no-color HEAD^ | clang-format-diff-6.0 -p1 -i
Just as C++ is meant to be refactored, right?
Differential Revision: https://reviews.llvm.org/D65381
llvm-svn: 368717
Summary:
Integer Set Library using retain-count based allocation which is not
modeled in MallocChecker.
Reviewed By: NoQ
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64680
llvm-svn: 366391
Since D57922, the config table contains every checker option, and it's default
value, so having it as an argument for getChecker*Option is redundant.
By the time any of the getChecker*Option function is called, we verified the
value in CheckerRegistry (after D57860), so we can confidently assert here, as
any irregularities detected at this point must be a programmer error. However,
in compatibility mode, verification won't happen, so the default value must be
restored.
This implies something else, other than adding removing one more potential point
of failure -- debug.ConfigDumper will always contain valid values for
checker/package options!
Differential Revision: https://reviews.llvm.org/D59195
llvm-svn: 361042
new expression.
This was voted into C++20 as a defect report resolution, so we
retroactively apply it to all prior language modes (though it can never
actually be used before C++11 mode).
llvm-svn: 360006
Under the term "subchecker", I mean checkers that do not have a checker class on
their own, like unix.MallocChecker to unix.DynamicMemoryModeling.
Since a checker object was required in order to retrieve checker options,
subcheckers couldn't possess options on their own.
This patch is also an excuse to change the argument order of getChecker*Option,
it always bothered me, now it resembles the actual command line argument
(checkername:option=value).
Differential Revision: https://reviews.llvm.org/D57579
llvm-svn: 355297
This patch effectively fixes the almost decade old checker naming issue.
The solution is to assert when CheckerManager::getChecker is called on an
unregistered checker, and assert when CheckerManager::registerChecker is called
on a checker that is already registered.
Differential Revision: https://reviews.llvm.org/D55429
llvm-svn: 352292
Unfortunately, up until now, the fact that certain checkers depended on one
another was known, but how these actually unfolded was hidden deep within the
implementation. For example, many checkers (like RetainCount, Malloc or CString)
modelled a certain functionality, and exposed certain reportable bug types to
the user. For example, while MallocChecker models many many different types of
memory handling, the actual "unix.MallocChecker" checker the user was exposed to
was merely and option to this modeling part.
Other than this being an ugly mess, this issue made resolving the checker naming
issue almost impossible. (The checker naming issue being that if a checker
registered more than one checker within its registry function, both checker
object recieved the same name) Also, if the user explicitly disabled a checker
that was a dependency of another that _was_ explicitly enabled, it implicitly,
without "telling" the user, reenabled it.
Clearly, changing this to a well structured, declarative form, where the
handling of dependencies are done on a higher level is very much preferred.
This patch, among the detailed things later, makes checkers declare their
dependencies within the TableGen file Checkers.td, and exposes the same
functionality to plugins and statically linked non-generated checkers through
CheckerRegistry::addDependency. CheckerRegistry now resolves these dependencies,
makes sure that checkers are added to CheckerManager in the correct order,
and makes sure that if a dependency is disabled, so will be every checker that
depends on it.
In detail:
* Add a new field to the Checker class in CheckerBase.td called Dependencies,
which is a list of Checkers.
* Move unix checkers before cplusplus, as there is no forward declaration in
tblgen :/
* Add the following new checkers:
- StackAddrEscapeBase
- StackAddrEscapeBase
- CStringModeling
- DynamicMemoryModeling (base of the MallocChecker family)
- IteratorModeling (base of the IteratorChecker family)
- ValistBase
- SecuritySyntaxChecker (base of bcmp, bcopy, etc...)
- NSOrCFErrorDerefChecker (base of NSErrorChecker and CFErrorChecker)
- IvarInvalidationModeling (base of IvarInvalidation checker family)
- RetainCountBase (base of RetainCount and OSObjectRetainCount)
* Clear up and registry functions in MallocChecker, happily remove old FIXMEs.
* Add a new addDependency function to CheckerRegistry.
* Neatly format RUN lines in files I looked at while debugging.
Big thanks to Artem Degrachev for all the guidance through this project!
Differential Revision: https://reviews.llvm.org/D54438
llvm-svn: 352287
Introduce the boolean ento::shouldRegister##CHECKERNAME(const LangOptions &LO)
function very similarly to ento::register##CHECKERNAME. This will force every
checker to implement this function, but maybe it isn't that bad: I saw a lot of
ObjC or C++ specific checkers that should probably not register themselves based
on some LangOptions (mine too), but they do anyways.
A big benefit of this is that all registry functions now register their checker,
once it is called, registration is guaranteed.
This patch is a part of a greater effort to reinvent checker registration, more
info here: D54438#1315953
Differential Revision: https://reviews.llvm.org/D55424
llvm-svn: 352277
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
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
Simon Pilgrim