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.
Implement support for C++2a requires-expressions.
Re-commit after compilation failure on some platforms due to alignment issues with PointerIntPair.
Differential Revision: https://reviews.llvm.org/D50360
This avoids unneeded copies when using a range-based for loops.
This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall.
Differential Revision: https://reviews.llvm.org/D70869
This is useful for clients that are relying on linearized CFGs for evaluating
subexpressions and want the default initializer to be evaluated properly.
The upcoming lifetime analysis is using this but it might also be useful
for the static analyzer at some point.
Differential Revision: https://reviews.llvm.org/D71642
This canonicalizes the representation of unknown pointer symbols,
which reduces the overall confusion in pointer cast representation.
Patch by Vince Bridgers!
Differential Revision: https://reviews.llvm.org/D70836
Some AST nodes which stands for implicit initialization is shared. The analyzer
will do the same evaluation on the same nodes resulting in the same state. The
analyzer will "cache out", i.e. it thinks that it visited an already existing
node in the exploded graph. This is not true in this case and we lose coverage.
Since these nodes do not really require any processing from the analyzer
we just omit them from the CFG.
Differential Revision: https://reviews.llvm.org/D71371
This patch introduced additional PointerEscape callbacks after conservative
calls for output parameters. This should not really affect the current
checkers but the upcoming FuchsiaHandleChecker relies on this heavily.
Differential Revision: https://reviews.llvm.org/D71224
It was a step in the right direction but it is not clear how can this
fit into the checker API at this point. The pre-escape happens in the
analyzer core and the checker has no control over it. If the checker
is not interestd in a pre-escape it would need to do additional work
on each escape to check if the escaped symbol is originated from an
"uninteresting" pre-escaped memory region. In order to keep the
checker API simple we abandoned this solution for now.
We will reland this once we have a better answer for what to do on the
checker side.
This reverts commit f3a28202ef.
We want to escape all symbols that are stored into escaped regions.
The problem is, we did not know which local regions were escaped. Until now.
This should fix some false positives like the one in the tests.
Differential Revision: https://reviews.llvm.org/D71152
When implementation of the block runtime is available, we should not
warn that block layout fields are uninitialized simply because they're
on the stack.
Fix a canonicalization problem for the newly added property accessor stubs that
was causing a wrong decl to be used for 'self' in the accessor's body farm.
Fix a crash when constructing a body farm for accessors of a property
that is declared and @synthesize'd in different (but related) interfaces.
Differential Revision: https://reviews.llvm.org/D70158
Let the checkers use a reference instead of a copy in a range-based
for loop.
This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall.
Differential Revision: https://reviews.llvm.org/D70047
When bugreporter::trackExpressionValue() is invoked on a DeclRefExpr,
it tries to do most of its computations over the node in which
this DeclRefExpr is computed, rather than on the error node (or whatever node
is stuffed into it). One reason why we can't simply use the error node is
that the binding to that variable might have already disappeared from the state
by the time the bug is found.
In case of the inlined defensive checks visitor, the DeclRefExpr node
is in fact sometimes too *early*: the call in which the inlined defensive check
has happened might have not been entered yet.
Change the visitor to be fine with tracking dead symbols (which it is totally
capable of - the collapse point for the symbol is still well-defined), and fire
it up directly on the error node. Keep using "LVState" to find out which value
should we be tracking, so that there weren't any problems with accidentally
loading an ill-formed value from a dead variable.
Differential Revision: https://reviews.llvm.org/D67932
This patch is motivated by (and factored out from)
https://reviews.llvm.org/D66121 which is a debug info bugfix. Starting
with DWARF 5 all Objective-C methods are nested inside their
containing type, and that patch implements this for synthesized
Objective-C properties.
1. SemaObjCProperty populates a list of synthesized accessors that may
need to inserted into an ObjCImplDecl.
2. SemaDeclObjC::ActOnEnd inserts forward-declarations for all
accessors for which no override was provided into their
ObjCImplDecl. This patch does *not* synthesize AST function
*bodies*. Moving that code from the static analyzer into Sema may
be a good idea though.
3. Places that expect all methods to have bodies have been updated.
I did not update the static analyzer's inliner for synthesized
properties to point back to the property declaration (see
test/Analysis/Inputs/expected-plists/nullability-notes.m.plist), which
I believed to be more bug than a feature.
Differential Revision: https://reviews.llvm.org/D68108
rdar://problem/53782400
Member operator declarations and member operator expressions
have different numbering of parameters and arguments respectively:
one of them includes "this", the other does not.
Account for this inconsistency when figuring out whether
the parameter needs to be manually rebound from the Environment
to the Store when entering a stack frame of an operator call,
as opposed to being constructed with a constructor and as such
already having the necessary Store bindings.
Differential Revision: https://reviews.llvm.org/D69155
The '->' thing has always been confusing; the actual operation '->'
translates to a pointer dereference together with adding a FieldRegion,
but FieldRegion on its own doesn't imply an additional pointer
dereference.
llvm-svn: 375281
One of the first attempts to reduce the size of the exploded graph dumps
was to skip the state dump as long as the state is the same as in all of
the predecessor nodes. With all the new facilities in place (node joining,
diff dumps), this feature doesn't do much, and when it does,
it's more harmful than useful. Let's remove it.
llvm-svn: 375280
The joined nodes now actually have the same state. That was intended
from the start but the original implementation turned out to be buggy.
Differential Revision: https://reviews.llvm.org/D69150
llvm-svn: 375278
ExplodedGraph nodes will now have a numeric identifier stored in them
which will keep track of the order in which the nodes were created
and it will be fully deterministic both accross runs and across machines.
This is extremely useful for debugging as it allows reliably setting
conditional breakpoints by node IDs.
llvm-svn: 375186
Part of C++20 Concepts implementation effort. Added Concept Specialization Expressions that are created when a concept is refe$
D41217 on Phabricator.
(recommit after fixing failing Parser test on windows)
llvm-svn: 374903
Part of C++20 Concepts implementation effort. Added Concept Specialization Expressions that are created when a concept is referenced with arguments, and tests thereof.
llvm-svn: 374882
Added parsing/sema/codegen support for 'parallel master taskloop'
constructs. Some of the clauses, like 'grainsize', 'num_tasks', 'final'
and 'priority' are not supported in full, only constant expressions can
be used currently in these clauses.
llvm-svn: 374791
Summary:
https://bugs.llvm.org/show_bug.cgi?id=43102
In today's edition of "Is this any better now that it isn't crashing?", I'd like to show you a very interesting test case with loop widening.
Looking at the included test case, it's immediately obvious that this is not only a false positive, but also a very bad bug report in general. We can see how the analyzer mistakenly invalidated `b`, instead of its pointee, resulting in it reporting a null pointer dereference error. Not only that, the point at which this change of value is noted at is at the loop, rather then at the method call.
It turns out that `FindLastStoreVisitor` works correctly, rather the supplied explodedgraph is faulty, because `BlockEdge` really is the `ProgramPoint` where this happens.
{F9855739}
So it's fair to say that this needs improving on multiple fronts. In any case, at least the crash is gone.
Full ExplodedGraph: {F9855743}
Reviewers: NoQ, xazax.hun, baloghadamsoftware, Charusso, dcoughlin, rnkovacs, TWeaver
Subscribers: JesperAntonsson, uabelho, Ka-Ka, bjope, whisperity, szepet, a.sidorin, mikhail.ramalho, donat.nagy, dkrupp, gamesh411, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66716
llvm-svn: 372269
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
At this point the PathDiagnostic, PathDiagnosticLocation, PathDiagnosticPiece
structures no longer rely on anything specific to Static Analyzer, so we can
move them out of it for everybody to use.
PathDiagnosticConsumers are still to be handed off.
Differential Revision: https://reviews.llvm.org/D67419
llvm-svn: 371661
This method of PathDiagnostic is a part of Static Analyzer's particular
path diagnostic construction scheme. As such, it doesn't belong to
the PathDiagnostic class, but to the Analyzer.
Differential Revision: https://reviews.llvm.org/D67418
llvm-svn: 371660
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
Allow attaching fixit hints to Static Analyzer BugReports.
Fixits are attached either to the bug report itself or to its notes
(path-sensitive event notes or path-insensitive extra notes).
Add support for fixits in text output (including the default text output that
goes without notes, as long as the fixit "belongs" to the warning).
Add support for fixits in the plist output mode.
Implement a fixit for the path-insensitive DeadStores checker. Only dead
initialization warning is currently covered.
Implement a fixit for the path-sensitive VirtualCall checker when the virtual
method is not pure virtual (in this case the "fix" is to suppress the warning
by qualifying the call).
Both fixits are under an off-by-default flag for now, because they
require more careful testing.
Differential Revision: https://reviews.llvm.org/D65182
llvm-svn: 371257
Most functions that our checkers react upon are not C-style variadic functions,
and therefore they have as many actual arguments as they have formal parameters.
However, it's not impossible to define a variadic function with the same name.
This will crash any checker that relies on CallDescription to check the number
of arguments but silently assumes that the number of parameters is the same.
Change CallDescription to check both the number of arguments and the number of
parameters by default.
If we're intentionally trying to match variadic functions, allow specifying
arguments and parameters separately (possibly omitting any of them).
For now we only have one CallDescription which would make use of those,
namely __builtin_va_start itself.
Differential Revision: https://reviews.llvm.org/D67019
llvm-svn: 371256
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
It was known to be a compile-time constant so it wasn't evaluated during
symbolic execution, but it wasn't evaluated as a compile-time constant either.
Differential Revision: https://reviews.llvm.org/D66565
llvm-svn: 370245
If the global variable has an initializer, we'll ignore it because we're usually
not analyzing the program from the beginning, which means that the global
variable may have changed before we start our analysis.
However when we're analyzing main() as the top-level function, we can rely
on global initializers to still be valid. At least in C; in C++ we have global
constructors that can still break this logic.
This patch allows the Static Analyzer to load constant initializers from
global variables if the top-level function of the current analysis is main().
Differential Revision: https://reviews.llvm.org/D65361
llvm-svn: 370244
According to the SARIF specification, "a text region does not include the character specified by endColumn".
Differential Revision: https://reviews.llvm.org/D65206
llvm-svn: 370060
As discussed on the mailing list, notes originating from the tracking of foreach
loop conditions are always meaningless.
Differential Revision: https://reviews.llvm.org/D66131
llvm-svn: 369613
Summary:
This patch introduces `DynamicCastInfo` similar to `DynamicTypeInfo` which
is stored in `CastSets` which are storing the dynamic cast informations of
objects based on memory regions. It could be used to store and check the
casts and prevent infeasible paths.
Reviewed By: NoQ
Differential Revision: https://reviews.llvm.org/D66325
llvm-svn: 369605
In D65724, I do a pretty thorough explanation about how I'm solving this
problem, I think that summary nails whats happening here ;)
Differential Revision: https://reviews.llvm.org/D65725
llvm-svn: 369596
Exactly what it says on the tin! Note that we're talking about interestingness
in general, hence this isn't a control-dependency-tracking specific patch.
Differential Revision: https://reviews.llvm.org/D65724
llvm-svn: 369589
We defined (on the mailing list and here on phabricator) 2 different cases where
retrieving information about a control dependency condition is very important:
* When the condition's last write happened in a different stack frame
* When the collapse point of the condition (when we can constrain it to be
true/false) didn't happen in the actual condition.
It seems like we solved this problem with the help of expression value tracking,
and have started working on better diagnostics notes about this process.
Expression value tracking is nothing more than registering a variety of visitors
to construct reports about it. Each of the registered visitors (ReturnVisitor,
FindLastStoreVisitor, NoStoreFuncVisitor, etc) have something to go by: a
MemRegion, an SVal, an ExplodedNode, etc. For this reason, better explaining a
last write is super simple, we can always just pass on some more information to
the visitor in question (as seen in D65575).
ConditionBRVisitor is a different beast, as it was built for a different
purpose. It is responsible for constructing events at, well, conditions, and is
registered only once, and isn't a part of the "expression value tracking
family". Unfortunately, it is also the visitor to tinker with for constructing
better diagnostics about the collapse point problem.
This creates a need for alternative way to communicate with ConditionBRVisitor
that a specific condition is being tracked for for the reason of being a control
dependency. Since at almost all PathDiagnosticEventPiece construction the
visitor checks interestingness, it makes sense to pair interestingness with a
reason as to why we marked an entity as such.
Differential Revision: https://reviews.llvm.org/D65723
llvm-svn: 369583
Can't add much more to the title! This is part 1, the case where the collapse
point isn't in the condition point is the responsibility of ConditionBRVisitor,
which I'm addressing in part 2.
Differential Revision: https://reviews.llvm.org/D65575
llvm-svn: 369574
Add defensive check that prevents a crash when we try to evaluate a destructor
whose this-value is a concrete integer that isn't a null.
Differential Revision: https://reviews.llvm.org/D65349
llvm-svn: 369450
Calling a pure virtual method during construction or destruction
is undefined behavior. It's worth it to warn about it by default.
That part is now known as the cplusplus.PureVirtualCall checker.
Calling a normal virtual method during construction or destruction
may be fine, but does behave unexpectedly, as it skips virtual dispatch.
Do not warn about this by default, but let projects opt in into it
by enabling the optin.cplusplus.VirtualCall checker manually.
Give the two parts differentiated warning text:
Before:
Call to virtual function during construction or destruction:
Call to pure virtual function during construction
Call to virtual function during construction or destruction:
Call to virtual function during destruction
After:
Pure virtual method call:
Call to pure virtual method 'X::foo' during construction
has undefined behavior
Unexpected loss of virtual dispatch:
Call to virtual method 'Y::bar' during construction
bypasses virtual dispatch
Also fix checker names in consumers that support them (eg., clang-tidy)
because we now have different checker names for pure virtual calls and
regular virtual calls.
Also fix capitalization in the bug category.
Differential Revision: https://reviews.llvm.org/D64274
llvm-svn: 369449
Summary:
This patch introduces a new `analyzer-config` configuration:
`-analyzer-config silence-checkers`
which could be used to silence the given checkers.
It accepts a semicolon separated list, packed into quotation marks, e.g:
`-analyzer-config silence-checkers="core.DivideZero;core.NullDereference"`
It could be used to "disable" core checkers, so they model the analysis as
before, just if some of them are too noisy it prevents to emit reports.
This patch also adds support for that new option to the scan-build.
Passing the option `-disable-checker core.DivideZero` to the scan-build
will be transferred to `-analyzer-config silence-checkers=core.DivideZero`.
Reviewed By: NoQ, Szelethus
Differential Revision: https://reviews.llvm.org/D66042
llvm-svn: 369078
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
Well, what is says on the tin I guess!
Some more changes:
* Move isInevitablySinking() from BugReporter.cpp to CFGBlock's interface
* Rename and move findBlockForNode() from BugReporter.cpp to
ExplodedNode::getCFGBlock()
Differential Revision: https://reviews.llvm.org/D65287
llvm-svn: 368836
Exactly what it says on the tin! The comments in the code detail this a
little more too.
Differential Revision: https://reviews.llvm.org/D64272
llvm-svn: 368817
When we're tracking a variable that is responsible for a null pointer
dereference or some other sinister programming error, we of course would like to
gather as much information why we think that the variable has that specific
value as possible. However, the newly introduced condition tracking shows that
tracking all values this thoroughly could easily cause an intolerable growth in
the bug report's length.
There are a variety of heuristics we discussed on the mailing list[1] to combat
this, all of them requiring to differentiate in between tracking a "regular
value" and a "condition".
This patch introduces the new `bugreporter::TrackingKind` enum, adds it to
several visitors as a non-optional argument, and moves some functions around to
make the code a little more coherent.
[1] http://lists.llvm.org/pipermail/cfe-dev/2019-June/062613.html
Differential Revision: https://reviews.llvm.org/D64270
llvm-svn: 368777
Summary:
The following code snippet taken from D64271#1572188 has an issue: namely,
because `flag`'s value isn't undef or a concrete int, it isn't being tracked.
int flag;
bool coin();
void foo() {
flag = coin();
}
void test() {
int *x = 0;
int local_flag;
flag = 1;
foo();
local_flag = flag;
if (local_flag)
x = new int;
foo();
local_flag = flag;
if (local_flag)
*x = 5;
}
This, in my opinion, makes no sense, other values may be interesting too.
Originally added by rC185608.
Differential Revision: https://reviews.llvm.org/D64287
llvm-svn: 368773
During the evaluation of D62883, I noticed a bunch of totally
meaningless notes with the pattern of "Calling 'A'" -> "Returning value"
-> "Returning from 'A'", which added no value to the report at all.
This patch (not only affecting tracked conditions mind you) prunes
diagnostic messages to functions that return a value not constrained to
be 0, and are also linear.
Differential Revision: https://reviews.llvm.org/D64232
llvm-svn: 368771
I feel this is kinda important, because in a followup patch I'm adding different
kinds of interestingness, and propagating the correct kind in BugReporter.cpp is
just one less thing to worry about.
Differential Revision: https://reviews.llvm.org/D65578
llvm-svn: 368755
Apparently this does literally nothing.
When you think about this, it makes sense. If something is really important,
we're tracking it anyways, and that system is sophisticated enough to mark
actually interesting statements as such. I wouldn't say that it's even likely
that subexpressions are also interesting (array[10 - x + x]), so I guess even
if this produced any effects, its probably undesirable.
Differential Revision: https://reviews.llvm.org/D65487
llvm-svn: 368752
In D65379, I briefly described the construction of bug paths from an
ExplodedGraph. This patch is about refactoring the code processing the bug path
into a bug report.
A part of finding a valid bug report was running all visitors on the bug path,
so we already have a (possibly empty) set of diagnostics for each ExplodedNode
in it.
Then, for each diagnostic consumer, we construct non-visitor diagnostic pieces.
* We first construct the final diagnostic piece (the warning), then
* We start ascending the bug path from the error node's predecessor (since the
error node itself was used to construct the warning event). For each node
* We check the location (whether its a CallEnter, CallExit) etc. We simultaneously
keep track of where we are with the execution by pushing CallStack when we see a
CallExit (keep in mind that everything is happening in reverse!), popping it
when we find a CallEnter, compacting them into a single PathDiagnosticCallEvent.
void f() {
bar();
}
void g() {
f();
error(); // warning
}
=== The bug path ===
(root) -> f's CallEnter -> bar() -> f's CallExit -> (error node)
=== Constructed report ===
f's CallEnter -> bar() -> f's CallExit
^ /
\ V
(root) ---> f's CallEvent --> (error node)
* We also keep track of different PathPieces different location contexts
* (CallEvent::path in the above example has f's LocationContext, while the
CallEvent itself is in g's context) in a LocationContextMap object. Construct
whatever piece, if any, is needed for the note.
* If we need to generate edges (or arrows) do so. Make sure to also connect
these pieces with the ones that visitors emitted.
* Clean up the constructed PathDiagnostic by making arrows nicer, pruning
function calls, etc.
So I complained about mile long function invocations with seemingly the same
parameters being passed around. This problem, as I see it, a natural candidate
for creating classes and tying them all together.
I tried very hard to make the implementation feel natural, like, rolling off the
tongue. I introduced 2 new classes: PathDiagnosticBuilder (I mean, I kept the
name but changed almost everything in it) contains every contextual information
(owns the bug path, the diagnostics constructed but the visitors, the BugReport
itself, etc) needed for constructing a PathDiagnostic object, and is pretty much
completely immutable. BugReportContruct is the object containing every
non-contextual information (the PathDiagnostic object we're constructing, the
current location in the bug path, the location context map and the call stack I
meantioned earlier), and is passed around all over the place as a single entity
instead of who knows how many parameters.
I tried to used constness, asserts, limiting visibility of fields to my
advantage to clean up the code big time and dramatically improve safety. Also,
whenever I found the code difficult to understand, I added comments and/or
examples.
Here's a complete list of changes and my design philosophy behind it:
* Instead of construcing a ReportInfo object (added by D65379) after finding a
valid bug report, simply return an optional PathDiagnosticBuilder object straight
away. Move findValidReport into the class as a static method. I find
GRBugReporter::generatePathDiagnostics a joy to look at now.
* Rename generatePathDiagnosticForConsumer to generate (maybe not needed, but
felt that way in the moment) and moved it to PathDiagnosticBuilder. If we don't
need to generate diagnostics, bail out straight away, like we always should have.
After that, construct a BugReportConstruct object, leaving the rest of the logic
untouched.
* Move all static methods that would use contextual information into
PathDiagnosticBuilder, reduce their parameter count drastically by simply
passing around a BugReportConstruct object.
* Glance at the code I removed: Could you tell what the original
PathDiagnosticBuilder::LC object was for? It took a gooood long while for me to
realize that nothing really. It is always equal with the LocationContext
associated with our current position in the bug path. Remove it completely.
* The original code contains the following expression quite a bit:
LCM[&PD.getActivePath()], so what does it mean? I said that we collect the
contexts associated with different PathPieces, but why would we ever modify that,
shouldn't it be set? Well, theoretically yes, but in the implementation, the
address of PathDiagnostic::getActivePath doesn't change if we move to an outer,
previously unexplored function. Add both descriptive method names and
explanations to BugReportConstruct to help on this.
* Add plenty of asserts, both for safety and as a poor man's documentation.
Differential Revision: https://reviews.llvm.org/D65484
llvm-svn: 368737
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
This patch refactors the utility functions and classes around the construction
of a bug path.
At a very high level, this consists of 3 steps:
* For all BugReports in the same BugReportEquivClass, collect all their error
nodes in a set. With that set, create a new, trimmed ExplodedGraph whose leafs
are all error nodes.
* Until a valid report is found, construct a bug path, which is yet another
ExplodedGraph, that is linear from a given error node to the root of the graph.
* Run all visitors on the constructed bug path. If in this process the report
got invalidated, start over from step 2.
Now, to the changes within this patch:
* Do not allow the invalidation of BugReports up to the point where the trimmed
graph is constructed. Checkers shouldn't add bug reports that are known to be
invalid, and should use visitors and argue about the entirety of the bug path if
needed.
* Do not calculate indices. I may be biased, but I personally find code like
this horrible. I'd like to point you to one of the comments in the original code:
SmallVector<const ExplodedNode *, 32> errorNodes;
for (const auto I : bugReports) {
if (I->isValid()) {
HasValid = true;
errorNodes.push_back(I->getErrorNode());
} else {
// Keep the errorNodes list in sync with the bugReports list.
errorNodes.push_back(nullptr);
}
}
Not on my watch. Instead, use a far easier to follow trick: store a pointer to
the BugReport in question, not an index to it.
* Add range iterators to ExplodedGraph's successors and predecessors, and a
visitor range to BugReporter.
* Rename TrimmedGraph to BugPathGetter. Because that is what it has always been:
no sane graph type should store an iterator-like state, or have an interface not
exposing a single graph-like functionalities.
* Rename ReportGraph to BugPathInfo, because it is only a linear path with some
other context.
* Instead of having both and out and in parameter (which I think isn't ever
excusable unless we use the out-param for caching), return a record object with
descriptive getter methods.
* Where descriptive names weren't sufficient, compliment the code with comments.
Differential Revision: https://reviews.llvm.org/D65379
llvm-svn: 368694
The goal of this refactoring effort was to better understand how interestingness
was propagated in BugReporter.cpp, which eventually turned out to be a dead end,
but with such a twist, I wouldn't even want to spoil it ahead of time. However,
I did get to learn a lot about how things are working in there.
In these series of patches, as well as cleaning up the code big time, I invite
you to study how BugReporter.cpp operates, and discuss how we could design this
file to reduce the horrible mess that it is.
This patch reverts a great part of rC162028, which holds the title "Allow
multiple PathDiagnosticConsumers to be used with a BugReporter at the same
time.". This, however doesn't imply that there's any need for multiple "layers"
or stacks of interesting symbols and regions, quite the contrary, I would argue
that we would like to generate the same amount of information for all output
types, and only process them differently.
Differential Revision: https://reviews.llvm.org/D65378
llvm-svn: 368689
Summary:
A condition could be a multi-line expression where we create the highlight
in separated chunks. PathDiagnosticPopUpPiece is not made for that purpose,
it cannot be added to multiple lines because we have only one ending part
which contains all the notes. So that it cannot have multiple endings and
therefore this patch narrows down the ranges of the highlight to the given
interesting variable of the condition. It prevents HTML-breaking injections.
Reviewed By: NoQ
Differential Revision: https://reviews.llvm.org/D65663
llvm-svn: 368382
Summary:
It allows discriminating between stack frames of the same call that is
called multiple times in a loop.
Thanks to Artem Dergachev for the great idea!
Reviewed By: NoQ
Tags: #clang
Differential Revision: https://reviews.llvm.org/D65587
llvm-svn: 367608
Summary:
When cross TU analysis is used it is possible that a macro expansion
is generated for a macro that is defined (and used) in other than
the main translation unit. To get the expansion for it the source
location in the original source file and original preprocessor
is needed.
Reviewers: martong, xazax.hun, Szelethus, ilya-biryukov
Reviewed By: Szelethus
Subscribers: mgorny, NoQ, ilya-biryukov, rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64638
llvm-svn: 367006
This patch is a major part of my GSoC project, aimed to improve the bug
reports of the analyzer.
TL;DR: Help the analyzer understand that some conditions are important,
and should be explained better. If an CFGBlock is a control dependency
of a block where an expression value is tracked, explain the condition
expression better by tracking it.
if (A) // let's explain why we believe A to be true
10 / x; // division by zero
This is an experimental feature, and can be enabled by the
off-by-default analyzer configuration "track-conditions".
In detail:
This idea was inspired by the program slicing algorithm. Essentially,
two things are used to produce a program slice (a subset of the program
relevant to a (statement, variable) pair): data and control
dependencies. The bug path (the linear path in the ExplodedGraph that leads
from the beginning of the analysis to the error node) enables to
analyzer to argue about data dependencies with relative ease.
Control dependencies are a different slice of the cake entirely.
Just because we reached a branch during symbolic execution, it
doesn't mean that that particular branch has any effect on whether the
bug would've occured. This means that we can't simply rely on the bug
path to gather control dependencies.
In previous patches, LLVM's IDFCalculator, which works on a control flow
graph rather than the ExplodedGraph was generalized to solve this issue.
We use this information to heuristically guess that the value of a tracked
expression depends greatly on it's control dependencies, and start
tracking them as well.
After plenty of evaluations this was seen as great idea, but still
lacking refinements (we should have different descriptions about a
conditions value), hence it's off-by-default.
Differential Revision: https://reviews.llvm.org/D62883
llvm-svn: 365207
Add a label to nodes that have a bug report attached or on which
the analysis was generally interrupted.
Fix printing has_report and implement printing is_sink in the graph dumper.
Differential Revision: https://reviews.llvm.org/D64110
llvm-svn: 364992
This commit adds a new builtin, __builtin_bit_cast(T, v), which performs a
bit_cast from a value v to a type T. This expression can be evaluated at
compile time under specific circumstances.
The compile time evaluation currently doesn't support bit-fields, but I'm
planning on fixing this in a follow up (some of the logic for figuring this out
is in CodeGen). I'm also planning follow-ups for supporting some more esoteric
types that the constexpr evaluator supports, as well as extending
__builtin_memcpy constexpr evaluation to use the same infrastructure.
rdar://44987528
Differential revision: https://reviews.llvm.org/D62825
llvm-svn: 364954
Due to RVO the target region of a function that returns an object by
value isn't necessarily a temporary object region; it may be an
arbitrary memory region. In particular, it may be a field of a bigger
object.
Make sure we don't invalidate the bigger object when said function is
evaluated conservatively.
Differential Revision: https://reviews.llvm.org/D63968
llvm-svn: 364870
When matching C standard library functions in the checker, it's easy to forget
that they are often implemented as macros that are expanded to builtins.
Such builtins would have a different name, so matching the callee identifier
would fail, or may sometimes have more arguments than expected, so matching
the exact number of arguments would fail, but this is fine as long as we have
all the arguments that we need in their respective places.
This patch adds a set of flags to the CallDescription class so that to handle
various special matching rules, and adds the first flag into this set,
which enables a more fuzzy matching for functions that
may be implemented as compiler builtins.
Differential Revision: https://reviews.llvm.org/D62556
llvm-svn: 364867
It encapsulates the procedure of figuring out whether a call event
corresponds to a function that's modeled by a checker.
Checker developers no longer need to worry about performance of
lookups into their own custom maps.
Add unittests - which finally test CallDescription itself as well.
Differential Revision: https://reviews.llvm.org/D62441
llvm-svn: 364866
The -analyzer-stats flag now allows you to find out how much time was spent
on AST-based analysis and on path-sensitive analysis and, separately,
on bug visitors, as they're occasionally a performance problem on their own.
The total timer wasn't useful because there's anyway a total time printed out.
Remove it.
Differential Revision: https://reviews.llvm.org/D63227
llvm-svn: 364266
Summary:
After evaluation it would be an Unknown value and tracking would be lost.
Reviewers: NoQ, xazax.hun, ravikandhadai, baloghadamsoftware, Szelethus
Reviewed By: NoQ
Subscribers: szepet, rnkovacs, a.sidorin, mikhail.ramalho, donat.nagy,
dkrupp, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63720
llvm-svn: 364259
Summary:
- Now we could see the `has_report` property in `trim-egraph` mode.
- This patch also removes the trailing comma after each node.
Reviewers: NoQ
Reviewed By: NoQ
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin,
mikhail.ramalho, Szelethus, donat.nagy, dkrupp, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63436
llvm-svn: 364193
Quotes around StringRegions are now escaped and unescaped correctly,
producing valid JSON.
Additionally, add a forgotten escape for Store values.
Differential Revision: https://reviews.llvm.org/D63519
llvm-svn: 363897
Include a unique pointer so that it was possible to figure out if it's
the same cluster in different program states. This allows comparing
dumps of different states against each other.
Differential Revision: https://reviews.llvm.org/D63362
llvm-svn: 363896
Location context ID is a property of the location context, not of an item
within it. It's useful to know the id even when there are no items
in the context, eg. for the purposes of figuring out how did contents
of the Environment for the same location context changed across states.
Differential Revision: https://reviews.llvm.org/D62754
llvm-svn: 363895
This changes the checker callback signature to use the modern, easy to
use interface. Additionally, this unblocks future work on allowing
checkers to implement evalCall() for calls that don't correspond to any
call-expression or require additional information that's only available
as part of the CallEvent, such as C++ constructors and destructors.
Differential Revision: https://reviews.llvm.org/D62440
llvm-svn: 363893
Summary:
This patch applies a change similar to rC363069, but for SARIF files.
The `%diff_sarif` lit substitution invokes `diff` with a non-portable
`-I` option. The intended effect can be achieved by normalizing the
inputs to `diff` beforehand. Such normalization can be done with
`grep -Ev`, which is also used by other tests.
Additionally, this patch updates the SARIF output to have a newline at
the end of the file. This makes it so that the SARIF file qualifies as a
POSIX text file, which increases the consumability of the generated file
in relation to various tools.
Reviewers: NoQ, sfertile, xingxue, jasonliu, daltenty, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, Charusso, jsji, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62952
llvm-svn: 363822
Often times, when an ArraySubscriptExpr was reported as null or
undefined, the bug report was difficult to understand, because the
analyzer explained why arr[i] has that value, but didn't realize that in
fact i's value is very important as well. This patch fixes this by
tracking the indices of arrays.
Differential Revision: https://reviews.llvm.org/D63080
llvm-svn: 363510
Summary:
When we traversed backwards on ExplodedNodes to see where processed the
given statement we `break` too early. With the current approach we do not
miss the CallExitEnd ProgramPoint which stands for an inlined call.
Reviewers: NoQ, xazax.hun, ravikandhadai, baloghadamsoftware, Szelethus
Reviewed By: NoQ
Subscribers: szepet, rnkovacs, a.sidorin, mikhail.ramalho, donat.nagy,
dkrupp, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62926
llvm-svn: 363491
nullptr_t does not access memory.
We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.
This reinstates r363337, reverted in r363352.
llvm-svn: 363429
Revert 363340 "Remove unused SK_LValueToRValue initialization step."
Revert 363337 "PR23833, DR2140: an lvalue-to-rvalue conversion on a glvalue of type"
Revert 363295 "C++ DR712 and others: handle non-odr-use resulting from an lvalue-to-rvalue conversion applied to a member access or similar not-quite-trivial lvalue expression."
llvm-svn: 363352
nullptr_t does not access memory.
We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.
This reinstates r345562, reverted in r346065, now that CodeGen's
handling of non-odr-used variables has been fixed.
llvm-svn: 363337
Summary:
As suggested in the review of D62949, this patch updates the plist
output to have a newline at the end of the file. This makes it so that
the plist output file qualifies as a POSIX text file, which increases
the consumability of the generated plist file in relation to various
tools.
Reviewers: NoQ, sfertile, xingxue, jasonliu, daltenty
Reviewed By: NoQ, xingxue
Subscribers: jsji, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63041
llvm-svn: 362992
Summary:
This new piece is similar to our macro expansion printing in HTML reports:
On mouse-hover event it pops up on variables. Similar to note pieces it
supports `plist` diagnostics as well.
It is optional, on by default: `add-pop-up-notes=true`.
Extra: In HTML reports `background-color: LemonChiffon` was too light,
changed to `PaleGoldenRod`.
Reviewers: NoQ, alexfh
Reviewed By: NoQ
Subscribers: cfe-commits, gerazo, gsd, george.karpenkov, alexfh, xazax.hun,
baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho,
Szelethus, donat.nagy, dkrupp
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60670
llvm-svn: 362014
The `cplusplus.SelfAssignment` checker has a visitor that is added
to every `BugReport` to mark the to branch of the self assignment
operator with e.g. `rhs == *this` and `rhs != *this`. With the new
`NoteTag` feature this visitor is not needed anymore. Instead the
checker itself marks the two branches using the `NoteTag`s.
Differential Revision: https://reviews.llvm.org/D62479
llvm-svn: 361818
When initialization of virtual base classes is skipped, we now tell the user
about it, because this aspect of C++ isn't very well-known.
The implementation is based on the new "note tags" feature (r358781).
In order to make use of it, allow note tags to produce prunable notes,
and move the note tag factory to CoreEngine.
Differential Revision: https://reviews.llvm.org/D61817
llvm-svn: 361682
This patch adds the run-time CFG branch that would skip initialization of
virtual base classes depending on whether the constructor is called from a
superclass constructor or not. Previously the Static Analyzer was already
skipping virtual base-class initializers in such constructors, but it wasn't
skipping their arguments and their potential side effects, which was causing
pr41300 (and was generally incorrect). The previous skipping behavior is
now replaced with a hard assertion that we're not even getting there due
to how our CFG works.
The new CFG element is under a CFG build option so that not to break other
consumers of the CFG by this change. Static Analyzer support for this change
is implemented.
Differential Revision: https://reviews.llvm.org/D61816
llvm-svn: 361681
Turn it into a variant class instead. This conversion does indeed save some code
but there's a plan to add support for more kinds of terminators that aren't
necessarily based on statements, and with those in mind it becomes more and more
confusing to have CFGTerminators implicitly convertible to a Stmt *.
Differential Revision: https://reviews.llvm.org/D61814
llvm-svn: 361586
Add the new frontend flag -analyzer-checker-option-help to display all
checker/package options.
Differential Revision: https://reviews.llvm.org/D57858
llvm-svn: 361552
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
The more entries we have in AnalyzerOptions::ConfigTable, the more helpful
debug.ConfigDumper is. With this patch, I'm pretty confident that it'll now emit
the entire state of the analyzer, minus the frontend flags.
It would be nice to reserve the config table specifically to checker options
only, as storing the regular analyzer configs is kinda redundant.
Differential Revision: https://reviews.llvm.org/D57922
llvm-svn: 361006
Summary:
This patch implements the source location builtins `__builtin_LINE(), `__builtin_FUNCTION()`, `__builtin_FILE()` and `__builtin_COLUMN()`. These builtins are needed to implement [`std::experimental::source_location`](https://rawgit.com/cplusplus/fundamentals-ts/v2/main.html#reflection.src_loc.creation).
With the exception of `__builtin_COLUMN`, GCC also implements these builtins, and Clangs behavior is intended to match as closely as possible.
Reviewers: rsmith, joerg, aaron.ballman, bogner, majnemer, shafik, martong
Reviewed By: rsmith
Subscribers: rnkovacs, loskutov, riccibruno, mgorny, kunitoki, alexr, majnemer, hfinkel, cfe-commits
Differential Revision: https://reviews.llvm.org/D37035
llvm-svn: 360937
When looking for the location context of the call site, unwrap block invocation
contexts because they are attached to the current AnalysisDeclContext
while what we need is the previous AnalysisDeclContext.
Differential Revision: https://reviews.llvm.org/D61545
llvm-svn: 360202
During my work on analyzer dependencies, I created a great amount of new
checkers that emitted no diagnostics at all, and were purely modeling some
function or another.
However, the user shouldn't really disable/enable these by hand, hence this
patch, which hides these by default. I intentionally chose not to hide alpha
checkers, because they have a scary enough name, in my opinion, to cause no
surprise when they emit false positives or cause crashes.
The patch introduces the Hidden bit into the TableGen files (you may remember
it before I removed it in D53995), and checkers that are either marked as
hidden, or are in a package that is marked hidden won't be displayed under
-analyzer-checker-help. -analyzer-checker-help-hidden, a new flag meant for
developers only, displays the full list.
Differential Revision: https://reviews.llvm.org/D60925
llvm-svn: 359720
Currently we always inline functions that have no branches, i.e. have exactly
three CFG blocks: ENTRY, some code, EXIT. This makes sense because when there
are no branches, it means that there's no exponential complexity introduced
by inlining such function. Such functions also don't trigger various fundamental
problems with our inlining mechanism, such as the problem of inlined
defensive checks.
Sometimes the CFG may contain more blocks, but in practice it still has
linear structure because all directions (except, at most, one) of all branches
turned out to be unreachable. When this happens, still treat the function
as "small". This is useful, in particular, for dealing with C++17 if constexpr.
Differential Revision: https://reviews.llvm.org/D61051
llvm-svn: 359531
the assertion is in fact incorrect: there is a cornercase in Objective-C++
in which a C++ object is not constructed with a constructor, but merely
zero-initialized. Namely, this happens when an Objective-C message is sent
to a nil and it is supposed to return a C++ object.
Differential Revision: https://reviews.llvm.org/D60988
llvm-svn: 359262
If macro "CHECK_X(x)" expands to something like "if (x != NULL) ...",
the "Assuming..." note no longer says "Assuming 'x' is equal to CHECK_X".
Differential Revision: https://reviews.llvm.org/D59121
llvm-svn: 359037
Summary:
The existing CTU mechanism imports `FunctionDecl`s where the definition is available in another TU. This patch extends that to VarDecls, to bind more constants.
- Add VarDecl importing functionality to CrossTranslationUnitContext
- Import Decls while traversing them in AnalysisConsumer
- Add VarDecls to CTU external mappings generator
- Name changes from "external function map" to "external definition map"
Reviewers: NoQ, dcoughlin, xazax.hun, george.karpenkov, martong
Reviewed By: xazax.hun
Subscribers: Charusso, baloghadamsoftware, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, george.karpenkov, mgorny, whisperity, szepet, rnkovacs, a.sidorin, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D46421
llvm-svn: 358968
When growing a body on a body farm, it's essential to use the same redeclaration
of the function that's going to be used during analysis. Otherwise our
ParmVarDecls won't match the ones that are used to identify argument regions.
This boils down to trusting the reasoning in AnalysisDeclContext. We shouldn't
canonicalize the declaration before farming the body because it makes us not
obey the sophisticated decision-making process of AnalysisDeclContext.
Differential Revision: https://reviews.llvm.org/D60899
llvm-svn: 358946
Stuffing invalid source locations (such as those in functions produced by
body farms) into path diagnostics causes crashes.
Fix a typo in a nearby function name.
Differential Revision: https://reviews.llvm.org/D60808
llvm-svn: 358945
Default RegionStore bindings represent values that can be obtained by loading
from anywhere within the region, not just the specific offset within the region
that they are said to be bound to. For example, default-binding a character \0
to an int (eg., via memset()) means that the whole int is 0, not just
that its lower byte is 0.
Even though memset and bzero were modeled this way, it didn't work correctly
when applied to simple variables. Eg., in
int x;
memset(x, 0, sizeof(x));
we did produce a default binding, but were unable to read it later, and 'x'
was perceived as an uninitialized variable even after memset.
At the same time, if we replace 'x' with a variable of a structure or array
type, accessing fields or elements of such variable was working correctly,
which was enough for most cases. So this was only a problem for variables of
simple integer/enumeration/floating-point/pointer types.
Fix loading default bindings from RegionStore for regions of simple variables.
Add a unit test to document the API contract as well.
Differential Revision: https://reviews.llvm.org/D60742
llvm-svn: 358722
Writing stuff into an argument variable is usually equivalent to writing stuff
to a local variable: it will have no effect outside of the function.
There's an important exception from this rule: if the argument variable has
a non-trivial destructor, the destructor would be invoked on
the parent stack frame, exposing contents of the otherwise dead
argument variable to the caller.
If such argument is the last place where a pointer is stored before the function
exits and the function is the one we've started our analysis from (i.e., we have
no caller context for it), we currently diagnose a leak. This is incorrect
because the destructor of the argument still has access to the pointer.
The destructor may deallocate the pointer or even pass it further.
Treat writes into such argument regions as "escapes" instead, suppressing
spurious memory leak reports but not messing with dead symbol removal.
Differential Revision: https://reviews.llvm.org/D60112
llvm-svn: 358321
The idea behind this heuristic is that normally the visitor is there to
inform the user that a certain function may fail to initialize a certain
out-parameter. For system header functions this is usually dictated by the
contract, and it's unlikely that the header function has accidentally
forgot to put the value into the out-parameter; it's more likely
that the user has intentionally skipped the error check.
Warnings on skipped error checks are more like security warnings;
they aren't necessarily useful for all users, and they should instead
be introduced on a per-API basis.
Differential Revision: https://reviews.llvm.org/D60107
llvm-svn: 357810
Requires making the llvm::MemoryBuffer* stored by SourceManager const,
which in turn requires making the accessors for that return const
llvm::MemoryBuffer*s and updating all call sites.
The original motivation for this was to use it and fix the TODO in
CodeGenAction.cpp's ConvertBackendLocation() by using the UnownedTag
version of createFileID, and since llvm::SourceMgr* hands out a const
llvm::MemoryBuffer* this is required. I'm not sure if fixing the TODO
this way actually works, but this seems like a good change on its own
anyways.
No intended behavior change.
Differential Revision: https://reviews.llvm.org/D60247
llvm-svn: 357724
It turns out that SourceManager::isInSystemHeader() crashes when an invalid
source location is passed into it. Invalid source locations are relatively
common: not only they come from body farms, but also, say, any function in C
that didn't come with a forward declaration would have an implicit
forward declaration with invalid source locations.
There's a more comfy API for us to use in the Static Analyzer:
CallEvent::isInSystemHeader(), so just use that.
Differential Revision: https://reviews.llvm.org/D59901
llvm-svn: 357329
It is now an inter-checker communication API, similar to the one that
connects MallocChecker/CStringChecker/InnerPointerChecker: simply a set of
setters and getters for a state trait.
Differential Revision: https://reviews.llvm.org/D59861
llvm-svn: 357326
The transfer function for the CFG element that represents a logical operation
computes the value of the operation and does nothing else. The element
appears after all the short circuit decisions were made, so they don't need
to be made again at this point.
Because our expression evaluation is imprecise, it is often hard to
discriminate between:
(1) we don't know the value of the RHS because we failed to evaluate it
and
(2) we don't know the value of the RHS because it didn't need to be evaluated.
This is hard because it depends on our knowledge about the value of the LHS
(eg., if LHS is true, then RHS in (LHS || RHS) doesn't need to be computed)
but LHS itself may have been evaluated imprecisely and we don't know whether
it is true or not. Additionally, the Analyzer wouldn't necessarily even remember
what the value of the LHS was because theoretically it's not really necessary
to know it for any future evaluations.
In order to work around these issues, the transfer function for logical
operations consists in looking at the ExplodedGraph we've constructed so far
in order to figure out from which CFG direction did we arrive here.
Such post-factum backtracking that doesn't involve looking up LHS and RHS values
is usually possible. However sometimes it fails because when we deduplicate
exploded nodes with the same program point and the same program state we may end
up in a situation when we reached the same program point from two or more
different directions.
By removing the assertion, we admit that the procedure indeed sometimes fails to
work. When it fails, we also admit that we don't know the value of the logical
operator.
Differential Revision: https://reviews.llvm.org/D59857
llvm-svn: 357325
Almost all path-sensitive checkers need to tell the user when something specific
to that checker happens along the execution path but does not constitute a bug
on its own. For instance, a call to operator delete in C++ has consequences
that are specific to a use-after-free bug. Deleting an object is not a bug
on its own, but when the Analyzer finds an execution path on which a deleted
object is used, it'll have to explain to the user when exactly during that path
did the deallocation take place.
Historically such custom notes were added by implementing "bug report visitors".
These visitors were post-processing bug reports by visiting every ExplodedNode
along the path and emitting path notes whenever they noticed that a change that
is relevant to a bug report occurs within the program state. For example,
it emits a "memory is deallocated" note when it notices that a pointer changes
its state from "allocated" to "deleted".
The "visitor" approach is powerful and efficient but hard to use because
such preprocessing implies that the developer first models the effects
of the event (say, changes the pointer's state from "allocated" to "deleted"
as part of operator delete()'s transfer function) and then forgets what happened
and later tries to reverse-engineer itself and figure out what did it do
by looking at the report.
The proposed approach tries to avoid discarding the information that was
available when the transfer function was evaluated. Instead, it allows the
developer to capture all the necessary information into a closure that
will be automatically invoked later in order to produce the actual note.
This should reduce boilerplate and avoid very painful logic duplication.
On the technical side, the closure is a lambda that's put into a special kind of
a program point tag, and a special bug report visitor visits all nodes in the
report and invokes all note-producing closures it finds along the path.
For now it is up to the lambda to make sure that the note is actually relevant
to the report. For instance, a memory deallocation note would be irrelevant when
we're reporting a division by zero bug or if we're reporting a use-after-free
of a different, unrelated chunk of memory. The lambda can figure these thing out
by looking at the bug report object that's passed into it.
A single checker is refactored to make use of the new functionality: MIGChecker.
Its program state is trivial, making it an easy testing ground for the first
version of the API.
Differential Revision: https://reviews.llvm.org/D58367
llvm-svn: 357323
Since rL335814, if the constraint manager cannot find a range set for `A - B`
(where `A` and `B` are symbols) it looks for a range for `B - A` and returns
it negated if it exists. However, if a range set for both `A - B` and `B - A`
is stored then it only returns the first one. If we both use `A - B` and
`B - A`, these expressions behave as two totally unrelated symbols. This way
we miss some useful deductions which may lead to false negatives or false
positives.
This tiny patch changes this behavior: if the symbolic expression the
constraint manager is looking for is a difference `A - B`, it tries to
retrieve the range for both `A - B` and `B - A` and if both exists it returns
the intersection of range `A - B` and the negated range of `B - A`. This way
every time a checker applies new constraints to the symbolic difference or to
its negated it always affects both the original difference and its negated.
Differential Revision: https://reviews.llvm.org/D55007
llvm-svn: 357167
r356634 didn't fix all the problems caused by r356222 - even though simple
constructors involving transparent init-list expressions are now evaluated
precisely, many more complicated constructors aren't, for other reasons.
The attached test case is an example of a constructor that will never be
evaluated precisely - simply because there isn't a constructor there (instead,
the program invokes run-time undefined behavior by returning without a return
statement that should have constructed the return value).
Fix another part of the problem for such situations: evaluate transparent
init-list expressions transparently, so that to avoid creating ill-formed
"transparent" nonloc::CompoundVals.
Differential Revision: https://reviews.llvm.org/D59622
llvm-svn: 356969
Summary:
If the constraint information is not changed between two program states the
analyzer has not learnt new information and made no report. But it is
possible to happen because we have no information at all. The new approach
evaluates the condition to determine if that is the case and let the user
know we just `Assuming...` some value.
Reviewers: NoQ, george.karpenkov
Reviewed By: NoQ
Subscribers: llvm-commits, xazax.hun, baloghadamsoftware, szepet, a.sidorin,
mikhail.ramalho, Szelethus, donat.nagy, dkrupp, gsd, gerazo
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D57410
llvm-svn: 356323
Summary:
Removed the `GDM` checking what could prevent reports made by this visitor.
Now we rely on constraint changes instead.
(It reapplies 356318 with a feature from 356319 because build-bot failure.)
Reviewers: NoQ, george.karpenkov
Reviewed By: NoQ
Subscribers: cfe-commits, jdoerfert, gerazo, xazax.hun, baloghadamsoftware,
szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp
Tags: #clang
Differential Revision: https://reviews.llvm.org/D54811
llvm-svn: 356322
Summary: If the constraint information is not changed between two program states the analyzer has not learnt new information and made no report. But it is possible to happen because we have no information at all. The new approach evaluates the condition to determine if that is the case and let the user know we just 'Assuming...' some value.
Reviewers: NoQ, george.karpenkov
Reviewed By: NoQ
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, gsd, gerazo
Tags: #clang
Differential Revision: https://reviews.llvm.org/D57410
llvm-svn: 356319
Summary: Removed the `GDM` checking what could prevent reports made by this visitor. Now we rely on constraint changes instead.
Reviewers: NoQ, george.karpenkov
Reviewed By: NoQ
Subscribers: jdoerfert, gerazo, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp
Tags: #clang
Differential Revision: https://reviews.llvm.org/D54811
llvm-svn: 356318
RegionStore now knows how to bind a nonloc::CompoundVal that represents the
value of an aggregate initializer when it has its initial segment of sub-values
correspond to base classes.
Additionally, fixes the crash from pr40022.
Differential Revision: https://reviews.llvm.org/D59054
llvm-svn: 356222
For a rather short code snippet, if debug.ReportStmts (added in this patch) was
enabled, a bug reporter visitor crashed:
struct h {
operator int();
};
int k() {
return h();
}
Ultimately, this originated from PathDiagnosticLocation::createMemberLoc, as it
didn't handle the case where it's MemberExpr typed parameter returned and
invalid SourceLocation for MemberExpr::getMemberLoc. The solution was to find
any related valid SourceLocaion, and Stmt::getBeginLoc happens to be just that.
Differential Revision: https://reviews.llvm.org/D58777
llvm-svn: 356161
Buildbot breaks when LLVm is compiled with memory sanitizer.
WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0xa3d16d8 in getMacroNameAndPrintExpansion(blahblah)
lib/StaticAnalyzer/Core/PlistDiagnostics.cpp:903:11
llvm-svn: 355911
When there is a functor-like macro which is passed as parameter to another
"function" macro then its parameters are not listed at the place of expansion:
#define foo(x) int bar() { return x; }
#define hello(fvar) fvar(0)
hello(foo)
int main() { 1 / bar(); }
Expansion of hello(foo) asserted Clang, because it expected an l_paren token in
the 3rd line after "foo", since it is a function-like token.
Patch by Tibor Brunner!
Differential Revision: https://reviews.llvm.org/D57893
llvm-svn: 355903
In the commited testfile, macro expansion (the one implemented for the plist
output) runs into an infinite recursion. The issue originates from the algorithm
being faulty, as in
#define value REC_MACRO_FUNC(value)
the "value" is being (or at least attempted) expanded from the same macro.
The solved this issue by gathering already visited macros in a set, which does
resolve the crash, but will result in an incorrect macro expansion, that would
preferably be fixed down the line.
Patch by Tibor Brunner!
Differential Revision: https://reviews.llvm.org/D57891
llvm-svn: 355705
Asserting on invalid input isn't very nice, hence the patch to emit an error
instead.
This is the first of many patches to overhaul the way we handle checker options.
Differential Revision: https://reviews.llvm.org/D57850
llvm-svn: 355704
Summary:
When comparing a symbolic region and a constant, the constant would be
widened or truncated to the width of a void pointer, meaning that the
constant could be incorrectly truncated when handling symbols for
non-default address spaces. In the attached test case this resulted in a
false positive since the constant was truncated to zero. To fix this,
widen/truncate the constant to the width of the symbol expression's
type.
This commit does not consider non-symbolic regions as I'm not sure how
to generalize getting the type there.
This fixes PR40814.
Reviewers: NoQ, zaks.anna, george.karpenkov
Reviewed By: NoQ
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, jdoerfert, Charusso, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D58665
llvm-svn: 355592
This patch includes the necessary code for converting between a fixed point type and integer.
This also includes constant expression evaluation for conversions with these types.
Differential Revision: https://reviews.llvm.org/D56900
llvm-svn: 355462
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
#define f(y) x
#define x f(x)
int main() { x; }
This example results a compilation error since "x" in the first line was not
defined earlier. However, the macro expression printer goes to an infinite
recursion on this example.
Patch by Tibor Brunner!
Differential Revision: https://reviews.llvm.org/D57892
llvm-svn: 354806
FindLastStoreBRVisitor tries to find the first node in the exploded graph where
the current value was assigned to a region. This node is called the "store
site". It is identified by a pair of Pred and Succ nodes where Succ already has
the binding for the value while Pred does not have it. However the visitor
mistakenly identifies a node pair as the store site where the value is a
`LazyCompoundVal` and `Pred` does not have a store yet but `Succ` has it. In
this case the `LazyCompoundVal` is different in the `Pred` node because it also
contains the store which is different in the two nodes. This error may lead to
crashes (a declaration is cast to a parameter declaration without check) or
misleading bug path notes.
In this patch we fix this problem by checking for unequal `LazyCompoundVals`: if
their region is equal, and their store is the same as the store of their nodes
we consider them as equal when looking for the "store site". This is an
approximation because we do not check for differences of the subvalues
(structure members or array elements) in the stores.
Differential Revision: https://reviews.llvm.org/D58067
llvm-svn: 353943
Now, instead of passing the reference to a shared_ptr, we pass the shared_ptr instead.
I've also removed the check if Z3 is present in CreateZ3ConstraintManager as this function already calls CreateZ3Solver that performs the exactly same check.
Differential Revision: https://reviews.llvm.org/D54976
llvm-svn: 353371
This patch moves the ConstraintSMT definition to the SMTConstraintManager header to make it easier to move the Z3 backend around.
We achieve this by not using shared_ptr anymore, as llvm::ImmutableSet doesn't seem to like it.
The solver specific exprs and sorts are cached in the Z3Solver object now and we move pointers to those objects around.
As a nice side-effect, SMTConstraintManager doesn't have to be a template anymore. Yay!
Differential Revision: https://reviews.llvm.org/D54975
llvm-svn: 353370
Memory region that correspond to a variable is identified by the variable's
declaration and, in case of local variables, the stack frame it belongs to.
The declaration needs to be canonical, otherwise we'd have two different
memory regions that correspond to the same variable.
Fix such bug for global variables with forward declarations and assert
that no other problems of this kind happen.
Differential Revision: https://reviews.llvm.org/D57619
llvm-svn: 353353
This reverts commit r341722.
The "postponed" mechanism turns out to be necessary in order to handle
situations when a symbolic region is only kept alive by implicit bindings
in the Store. Otherwise the region is never scanned by the Store's worklist
and the binding gets dropped despite being live, as demonstrated
by the newly added tests.
Differential Revision: https://reviews.llvm.org/D57554
llvm-svn: 353350
When a function takes the address of a field the analyzer will no longer
assume that the function will change other fields of the enclosing structs.
Differential Revision: https://reviews.llvm.org/D57230
llvm-svn: 352473
As noted in https://bugs.llvm.org/show_bug.cgi?id=36651, the specialization for
isPodLike<std::pair<...>> did not match the expectation of
std::is_trivially_copyable which makes the memcpy optimization invalid.
This patch renames the llvm::isPodLike trait into llvm::is_trivially_copyable.
Unfortunately std::is_trivially_copyable is not portable across compiler / STL
versions. So a portable version is provided too.
Note that the following specialization were invalid:
std::pair<T0, T1>
llvm::Optional<T>
Tests have been added to assert that former specialization are respected by the
standard usage of llvm::is_trivially_copyable, and that when a decent version
of std::is_trivially_copyable is available, llvm::is_trivially_copyable is
compared to std::is_trivially_copyable.
As of this patch, llvm::Optional is no longer considered trivially copyable,
even if T is. This is to be fixed in a later patch, as it has impact on a
long-running bug (see r347004)
Note that GCC warns about this UB, but this got silented by https://reviews.llvm.org/D50296.
Differential Revision: https://reviews.llvm.org/D54472
llvm-svn: 351701
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
Add a defensive check against an invalid destructor in the CFG.
Unions with fields with destructors have their own destructor implicitly
deleted. Due to a bug in the CFG we're still trying to evaluate them
at the end of the object's lifetime and crash because we are unable
to find the destructor's declaration.
rdar://problem/47362608
Differential Revision: https://reviews.llvm.org/D56899
llvm-svn: 351610
SymbolReaper now realizes that our liveness analysis isn't sharp enough
to discriminate between liveness of, say, variables and their fields.
Surprisingly, this didn't quite work before: having a variable live only
through Environment (eg., calling a C++ method on a local variable
as the last action ever performed on that variable) would not keep the
region value symbol of a field of that variable alive.
It would have been broken in the opposite direction as well, but both
Environment and RegionStore use the scanReachableSymbols mechanism for finding
live symbols regions within their values, and due to that they accidentally
end up marking the whole chain of super-regions as live when at least one
sub-region is known to be live.
It is now a direct responsibility of SymbolReaper to maintain this invariant,
and a unit test was added in order to make sure it stays that way.
Differential Revision: https://reviews.llvm.org/D56632
rdar://problem/46914108
llvm-svn: 351499
Summary:
https://reviews.llvm.org/D54862 removed the usages of `ASTContext&` from
within the `CXXMethodDecl::getThisType` method. Remove the parameter
altogether, as well as all usages of it. This does not result in any
functional change because the parameter was unused since
https://reviews.llvm.org/D54862.
Test Plan: check-clang
Reviewers: akyrtzi, mikael
Reviewed By: mikael
Subscribers: mehdi_amini, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D56509
llvm-svn: 350914
Several headers would fail to compile if other headers were not previously
included. The usual issue is that a class is forward declared, but the
full definition is needed. The requirement for the definition is use of
isa/dyn_cast or calling functions of pointer-packed data types such as
DenseMap or PointerIntPair. Add missing includes to these headers.
SVals.h required an out-of-line method definition in the .cpp file to avoid
circular inclusion of headers with BasicValueFactory.h
llvm-svn: 350913
We need to be able to emit the diagnostic at PreImplicitCall,
and the patch implements this functionality.
However, for now the need for emitting such diagnostics is not all that great:
it is only necessary to not crash when emitting a false positive due to an
unrelated issue of having dead symbol collection not working properly.
Coming up with a non-false-positive test seems impossible with the current
set of checkers, though it is likely to be needed for good things as well
in the future.
Differential Revision: https://reviews.llvm.org/D56042
rdar://problem/46911462
llvm-svn: 350907
Make sure all checks for attributes go through a centralized function,
which checks whether attribute handling is enabled, and performs
validation. The type of the attribute is returned.
Sadly, metaprogramming is required as attributes have no sensible static
getters.
Differential Revision: https://reviews.llvm.org/D56222
llvm-svn: 350862
Summary: The LocationE parameter of evalStore is documented as "The location expression that is stored to". When storing from an increment / decrement operator this was not satisfied. In user code this causes an inconsistency between the SVal and Stmt parameters of checkLocation.
Reviewers: NoQ, dcoughlin, george.karpenkov
Reviewed By: NoQ
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, cfe-commits
Differential Revision: https://reviews.llvm.org/D55701
llvm-svn: 350528
Previously, argument effects were stored in a method variable, which was
effectively global.
The global state was reset at each (hopefully) entrance point to the
summary construction,
and every function could modify it.
Differential Revision: https://reviews.llvm.org/D56036
llvm-svn: 350057
This patch is a different approach to landing the reverted r349701.
It is expected to have the same object (memory region) treated as if it has
different types in different program points. The correct behavior for
RegionStore when an object is stored as an object of type T1 but loaded as
an object of type T2 is to store the object as if it has type T1 but cast it
to T2 during load.
Note that the cast here is some sort of a "reinterpret_cast" (even in C). For
instance, if you store an integer and load a float, you won't get your integer
represented as a float; instead, you will get garbage.
Admit that we cannot perform the cast and return an unknown value.
Differential Revision: https://reviews.llvm.org/D55875
rdar://problem/45062567
llvm-svn: 349984
If it ends with "Retain" like CFRetain and returns a CFTypeRef like CFRetain,
then it is not necessarily a CFRetain. But it is indeed true that these two
return something retained.
Differential Revision: https://reviews.llvm.org/D55907
rdar://problem/39390714
llvm-svn: 349862
This adds anchors to all of the documented checks so that you can directly link to a check by a stable name. This is useful because the SARIF file format has a field for specifying a URI to documentation for a rule and some viewers, like CodeSonar, make use of this information. These links are then exposed through the SARIF exporter.
llvm-svn: 349812
This reverts commit r349701.
The patch was incorrect. The whole point of CastRetrievedVal()
is to handle the case in which the type from which the cast is made
(i.e., the "type" of value `V`) has nothing to do with the type of
the region it was loaded from (i.e., `R->getValueType()`).
Differential Revision: https://reviews.llvm.org/D55875
rdar://problem/45062567
llvm-svn: 349798
It is expected to have the same object (memory region) treated as if it has
different types in different program points. The correct behavior for
RegionStore when an object is stored as an object of type T1 but loaded as
an object of type T2 is to store the object as if it has type T1 but cast it
to T2 during load.
Note that the cast here is some sort of a "reinterpret_cast" (even in C). For
instance, if you store a float and load an integer, you won't have your float
rounded to an integer; instead, you will have garbage.
Admit that we cannot perform the cast as long as types we're dealing with are
non-trivial (neither integers, nor pointers).
Of course, if the cast is not necessary (eg, T1 == T2), we can still load the
value just fine.
Differential Revision: https://reviews.llvm.org/D55875
rdar://problem/45062567
llvm-svn: 349701
Static Analyzer processes the program function-by-function, sometimes diving
into other functions ("inlining" them). When an object is returned from an
inlined function, Return Value Optimization is modeled, and the returned object
is constructed at its return location directly.
When an object is returned from the function from which the analysis has started
(the top stack frame of the analysis), the return location is unknown. Model it
with a SymbolicRegion based on a conjured symbol that is specifically tagged for
that purpose, because this is generally the correct way to symbolicate
unknown locations in Static Analyzer.
Fixes leak false positives when an object is returned from top frame in C++17:
objects that are put into a SymbolicRegion-based memory region automatically
"escape" and no longer get reported as leaks. This only applies to C++17 return
values with destructors, because it produces a redundant CXXBindTemporaryExpr
in the call site, which confuses our liveness analysis. The actual fix
for liveness analysis is still pending, but it is no longer causing problems.
Additionally, re-enable temporary destructor tests in C++17.
Differential Revision: https://reviews.llvm.org/D55804
rdar://problem/46217550
llvm-svn: 349696
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
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
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
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
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
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
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
From what I can see, this should be the last patch needed to replicate macro
argument expansions.
Differential Revision: https://reviews.llvm.org/D52988
llvm-svn: 348025
During the review of D41938 a condition check with an early exit accidentally
slipped into a branch, leaving the other branch unprotected. This may result in
an assertion later on. This hotfix moves this contition check outside of the
branch.
Differential Revision: https://reviews.llvm.org/D55051
llvm-svn: 347981
It's an old bug that consists in stale references to symbols remaining in the
GDM if they disappear from other program state sections as a result of any
operation that isn't the actual dead symbol collection. The most common example
here is:
FILE *fp = fopen("myfile.txt", "w");
fp = 0; // leak of file descriptor
In this example the leak were not detected previously because the symbol
disappears from the public part of the program state due to evaluating
the assignment. For that reason the checker never receives a notification
that the symbol is dead, and never reports a leak.
This patch not only causes leak false negatives, but also a number of other
problems, including false positives on some checkers.
What's worse, even though the program state contains a finite number of symbols,
the set of symbols that dies is potentially infinite. This means that is
impossible to compute the set of all dead symbols to pass off to the checkers
for cleaning up their part of the GDM.
No longer compute the dead set at all. Disallow iterating over dead symbols.
Disallow querying if any symbols are dead. Remove the API for marking symbols
as dead, as it is no longer necessary. Update checkers accordingly.
Differential Revision: https://reviews.llvm.org/D18860
llvm-svn: 347953
The "free" call frees the object immediately, ignoring the reference count.
Sadly, it is actually used in a few places, so we need to model it.
Differential Revision: https://reviews.llvm.org/D55092
llvm-svn: 347950
Summary: Left only the constructors that are actually required, and marked the move constructors as deleted. They are not used anymore and we were never sure they've actually worked correctly.
Reviewers: george.karpenkov, NoQ
Reviewed By: george.karpenkov
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, Szelethus, donat.nagy, dkrupp
Differential Revision: https://reviews.llvm.org/D54974
llvm-svn: 347777
This was reverted in r347656 due to me thinking it caused a miscompile of
Chromium. Turns out it was the Chromium code that was broken.
llvm-svn: 347756
This caused a miscompile in Chrome (see crbug.com/908372) that's
illustrated by this small reduction:
static bool f(int *a, int *b) {
return !__builtin_constant_p(b - a) || (!(b - a));
}
int arr[] = {1,2,3};
bool g() {
return f(arr, arr + 3);
}
$ clang -O2 -S -emit-llvm a.cc -o -
g() should return true, but after r347417 it became false for some reason.
This also reverts the follow-up commits.
r347417:
> Re-Reinstate 347294 with a fix for the failures.
>
> Don't try to emit a scalar expression for a non-scalar argument to
> __builtin_constant_p().
>
> Third time's a charm!
r347446:
> The result of is.constant() is unsigned.
r347480:
> A __builtin_constant_p() returns 0 with a function type.
r347512:
> isEvaluatable() implies a constant context.
>
> Assume that we're in a constant context if we're asking if the expression can
> be compiled into a constant initializer. This fixes the issue where a
> __builtin_constant_p() in a compound literal was diagnosed as not being
> constant, even though it's always possible to convert the builtin into a
> constant.
r347531:
> A "constexpr" is evaluated in a constant context. Make sure this is reflected
> if a __builtin_constant_p() is a part of a constexpr.
llvm-svn: 347656
Summary:
A __builtin_constant_p may end up with a constant after inlining. Use
the is.constant intrinsic if it's a variable that's in a context where
it may resolve to a constant, e.g., an argument to a function after
inlining.
Reviewers: rsmith, shafik
Subscribers: jfb, kristina, cfe-commits, nickdesaulniers, jyknight
Differential Revision: https://reviews.llvm.org/D54355
llvm-svn: 347294
CheckerOptInfo feels very much out of place in CheckerRegistration.cpp, so I
moved it to CheckerRegistry.h.
Differential Revision: https://reviews.llvm.org/D54397
llvm-svn: 347157
With z3-4.8.1:
../tools/clang/lib/StaticAnalyzer/Core/Z3ConstraintManager.cpp:49:40: error:
'Z3_get_error_msg_ex' was not declared in this scope
../tools/clang/lib/StaticAnalyzer/Core/Z3ConstraintManager.cpp:49:40: note:
suggested alternative: 'Z3_get_error_msg'
Formerly used Z3_get_error_msg_ex() as one could find in z3-4.7.1 states:
"Retained function name for backwards compatibility within v4.1"
And it is implemented only as a forwarding call:
return Z3_get_error_msg(c, err);
Differential Revision: https://reviews.llvm.org/D54391
llvm-svn: 346635
Summary:
Compound literals, enums, file-scoped arrays, etc. require their
initializers and size specifiers to be constant. Wrap the initializer
expressions in a ConstantExpr so that we can easily check for this later
on.
Reviewers: rsmith, shafik
Reviewed By: rsmith
Subscribers: cfe-commits, jyknight, nickdesaulniers
Differential Revision: https://reviews.llvm.org/D53921
llvm-svn: 346455
One of the reasons why AnalyzerOptions is so chaotic is that options can be
retrieved from the command line whenever and wherever. This allowed for some
options to be forgotten for a looooooong time. Have you ever heard of
"region-store-small-struct-limit"? In order to prevent this in the future, I'm
proposing to restrict AnalyzerOptions' interface so that only checker options
can be retrieved without special getters. I would like to make every option be
accessible only through a getter, but checkers from plugins are a thing, so I'll
have to figure something out for that.
This also forces developers who'd like to add a new option to register it
properly in the .def file.
This is done by
* making the third checker pointer parameter non-optional, and checked by an
assert to be non-null.
* I added new, but private non-checkers option initializers, meant only for
internal use,
* Renamed these methods accordingly (mind the consistent name for once with
getBooleanOption!):
- getOptionAsString -> getCheckerStringOption,
- getOptionAsInteger -> getCheckerIntegerOption
* The 3 functions meant for initializing data members (with the not very
descriptive getBooleanOption, getOptionAsString and getOptionAsUInt names)
were renamed to be overloads of the getAndInitOption function name.
* All options were in some way retrieved via getCheckerOption. I removed it, and
moved the logic to getStringOption and getCheckerStringOption. This did cause
some code duplication, but that's the only way I could do it, now that checker
and non-checker options are separated. Note that the non-checker version
inserts the new option to the ConfigTable with the default value, but the
checker version only attempts to find already existing entries. This is how
it always worked, but this is clunky and I might end reworking that too, so we
can eventually get a ConfigTable that contains the entire configuration of the
analyzer.
Differential Revision: https://reviews.llvm.org/D53483
llvm-svn: 346113
Windows buildbots break with the previous commit '[analyzer][PlistMacroExpansion]
Part 2.: Retrieving the macro name and primitive expansion'. This patch attempts
to solve this issue.
llvm-svn: 346112
This patch adds a couple new functions to acquire the macro's name, and also
expands it, although it doesn't expand the arguments, as seen from the test files
Differential Revision: https://reviews.llvm.org/D52794
llvm-svn: 346095
This exposes a (known) CodeGen bug: it can't cope with emitting lvalue
expressions that denote non-odr-used but usable-in-constant-expression
variables. See PR39528 for a testcase.
Reverted for now until that issue can be fixed.
llvm-svn: 346065
I'm in the process of refactoring AnalyzerOptions. The main motivation behind
here is to emit warnings if an invalid -analyzer-config option is given from the
command line, and be able to list them all.
In this patch, I'm moving all analyzer options to a def file, and move 2 enums
to global namespace.
Differential Revision: https://reviews.llvm.org/D53277
llvm-svn: 345986
I'm in the process of refactoring AnalyzerOptions. The main motivation behind
here is to emit warnings if an invalid -analyzer-config option is given from
the command line, and be able to list them all.
In this patch, I found some flags that should've been used as checker options,
or have absolutely no mention of in AnalyzerOptions, or are nonexistent.
- NonLocalizedStringChecker now uses its "AggressiveReport" flag as a checker
option
- lib/StaticAnalyzer/Frontend/ModelInjector.cpp now accesses the "model-path"
option through a getter in AnalyzerOptions
- -analyzer-config path-diagnostics-alternate=false is not a thing, I removed it,
- lib/StaticAnalyzer/Checkers/AllocationDiagnostics.cpp and
lib/StaticAnalyzer/Checkers/AllocationDiagnostics.h are weird, they actually
only contain an option getter. I deleted them, and fixed RetainCountChecker
to get it's "leak-diagnostics-reference-allocation" option as a checker option,
- "region-store-small-struct-limit" has a proper getter now.
Differential Revision: https://reviews.llvm.org/D53276
llvm-svn: 345985
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
SARIF allows you to export descriptions about rules that are present in the SARIF log. Expose the help text table generated into Checkers.inc as the rule's "full description" and export all of the rules present in the analysis output. This information is useful for analysis result viewers like CodeSonar.
llvm-svn: 345874
This removes the Step property (which can be calculated by consumers trivially), and updates the schema and version numbers accordingly.
llvm-svn: 345823
Trusting summaries of inlined code would require a more thorough work,
as the current approach was causing too many false positives, as the new
example in test. The culprit lies in the fact that we currently escape
all variables written into a field (but not passed off to unknown
functions!), which can result in inconsistent behavior.
rdar://45655344
Differential Revision: https://reviews.llvm.org/D53902
llvm-svn: 345746
This is the first part of the implementation of the inclusion of macro
expansions into the plist output. It adds a new flag that adds a new
"macro_expansions" entry to each report that has PathDiagnosticPieces that were
expanded from a macro. While there's an entry for each macro expansion, both
the name of the macro and what it expands to is missing, and will be implemented
in followup patches.
Differential Revision: https://reviews.llvm.org/D52742
llvm-svn: 345724
A ConstantExpr class represents a full expression that's in a context where a
constant expression is required. This class reflects the path the evaluator
took to reach the expression rather than the syntactic context in which the
expression occurs.
In the future, the class will be expanded to cache the result of the evaluated
expression so that it's not needlessly re-evaluated
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D53475
llvm-svn: 345692
This allows users to specify SARIF (https://github.com/oasis-tcs/sarif-spec) as the output from the clang static analyzer so that the results can be read in by other tools, such as extensions to Visual Studio and VSCode, as well as static analyzers like CodeSonar.
llvm-svn: 345628
nullptr_t does not access memory.
We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.
llvm-svn: 345562
This has been a long time coming. Note the usage of AnalyzerOptions: I'll need
it for D52742, and added it in rC343620. The main motivation for this was that
I'll need to add yet another parameter to every single function, and some
functions would reach their 10th parameter with that change.
llvm-svn: 345531
Nodes which have only one predecessor and only one successor can not
always be hidden, even if all states are the same.
An additional condition is needed: the predecessor may have only one successor.
This can be seen on this example:
```
A
/ \
B C
\ /
D
```
Nodes B and C can not be hidden even if all nodes in the graph have the
same state.
Differential Revision: https://reviews.llvm.org/D53735
llvm-svn: 345341
Previously, OSDynamicCast was modeled as an identity.
This is not correct: the output of OSDynamicCast may be zero even if the
input was not zero (if the class is not of desired type), and thus the
modeling led to false positives.
Instead, we are doing eager state split:
in one branch, the returned value is identical to the input parameter,
and in the other branch, the returned value is zero.
This patch required a substantial refactoring of canEval infrastructure,
as now it can return different function summaries, and not just true/false.
rdar://45497400
Differential Revision: https://reviews.llvm.org/D53624
llvm-svn: 345338
Summary:
This patch moves the last method in `Z3ConstraintManager` to `SMTConstraintManager`: `canReasonAbout()`.
The `canReasonAbout()` method checks if a given `SVal` can be encoded in SMT. I've added a new method to the SMT API to return true if a solver can encode floating-point arithmetics and it was enough to make `canReasonAbout()` solver independent.
As an annoying side-effect, `Z3ConstraintManager` is pretty empty now and only (1) creates the Z3 solver object by calling `CreateZ3Solver()` and (2) instantiates `SMTConstraintManager`. Maybe we can get rid of this class altogether in the future: a `CreateSMTConstraintManager()` method that does (1) and (2) and returns the constraint manager object?
Reviewers: george.karpenkov, NoQ
Reviewed By: george.karpenkov
Subscribers: mehdi_amini, xazax.hun, szepet, a.sidorin, dexonsmith, Szelethus, donat.nagy, dkrupp
Differential Revision: https://reviews.llvm.org/D53694
llvm-svn: 345284
Summary:
Getting an `APSInt` from the model always returned an unsigned integer because of the unused parameter.
This was not breaking any test case because no code relies on the actual value of the integer returned here, but rather it is only used to check if a symbol has more than one solution in `getSymVal`.
Reviewers: NoQ, george.karpenkov
Reviewed By: george.karpenkov
Subscribers: xazax.hun, szepet, a.sidorin, Szelethus, donat.nagy, dkrupp
Differential Revision: https://reviews.llvm.org/D53637
llvm-svn: 345283
trackNullOrUndefValue is a long and confusing name,
and it does not actually reflect what the function is doing.
Give a function a new name, with a relatively clear semantics.
Also remove some dead code.
Differential Revision: https://reviews.llvm.org/D52758
llvm-svn: 345064
This patch is a part of https://reviews.llvm.org/D48456 in an attempt to split
the casting logic up into smaller patches. This contains the code for casting
from fixed point types to boolean types.
Differential Revision: https://reviews.llvm.org/D53308
llvm-svn: 345063
I'm in the process of refactoring AnalyzerOptions. The main motivation behind
here is to emit warnings if an invalid -analyzer-config option is given from the
command line, and be able to list them all.
This first NFC patch contains small modifications to make AnalyzerOptions.cpp a
little more consistent.
Differential Revision: https://reviews.llvm.org/D53274
llvm-svn: 344870
The GDMIndex functions return a pointer that's used as a key for looking up
data, but addresses of local statics defined in header files aren't the same
across shared library boundaries and the result is that analyzer plugins
can't access this data.
Event types are uniqued by using the addresses of a local static defined
in a header files, but it isn't the same across shared library boundaries
and plugins can't currently handle ImplicitNullDerefEvents.
Patches by Joe Ranieri!
Differential Revision: https://reviews.llvm.org/D52905
Differential Revision: https://reviews.llvm.org/D52906
llvm-svn: 344823
In C++17, when class C has large alignment value, a special case of
overload resolution rule kicks in for expression new C that causes the aligned
version of operator new() to be called. The aligned new has two arguments:
size and alignment. However, the new-expression has only one "argument":
the construct-expression for C(). This causes a false positive in
core.CallAndMessage's check for matching number of arguments and number
of parameters.
Update CXXAllocatorCall, which is a CallEvent sub-class for operator new calls
within new-expressions, so that the number of arguments always matched
the number of parameters.
rdar://problem/44738501
Differential Revision: https://reviews.llvm.org/D52957
llvm-svn: 344539
This patch is a part of https://reviews.llvm.org/D48456 in an attempt to
split them up. This contains the code for casting between fixed point types
and other fixed point types.
The method for converting between fixed point types is based off the convert()
method in APFixedPoint.
Differential Revision: https://reviews.llvm.org/D50616
llvm-svn: 344530
Summary:
Enhanced support for Z3 in the cmake configuration of clang; now it is possible to specify any arbitrary Z3 install prefix (CLANG_ANALYZER_Z3_PREFIX) to cmake with lib (or bin) and include folders. Before the patch only in cmake default locations
were searched (https://cmake.org/cmake/help/v3.4/command/find_path.html).
Specifying any CLANG_ANALYZER_Z3_PREFIX will force also CLANG_ANALYZER_BUILD_Z3 to ON.
Removed also Z3 4.5 version requirement since it was not checked, and now Clang works with Z3 4.7
Reviewers: NoQ, george.karpenkov, mikhail.ramalho
Reviewed By: george.karpenkov
Subscribers: rnkovacs, NoQ, esteffin, george.karpenkov, delcypher, ddcc, mgorny, xazax.hun, szepet, a.sidorin, Szelethus
Tags: #clang
Differential Revision: https://reviews.llvm.org/D50818
llvm-svn: 344464
Doesn't do much despite sounding quite bad, but fixes an exotic test case where
liveness of a nonloc::LocAsInteger array index is now evaluated correctly.
Differential Revision: https://reviews.llvm.org/D52667
llvm-svn: 343631
I intend to add a new flag macro-expnasions-as-events, and unfortunately
I'll only be able to convert the macro piece into an event one once I'm
about to emit it, due to the lack of an avaible Preprocessor object in
the BugReporter.
Differential Revision: https://reviews.llvm.org/D52787
llvm-svn: 343620
Summary:
Several improvements in preparation for the new backends.
Refactoring:
- Removed duplicated methods `fromBoolean`, `fromAPSInt`, `fromInt` and `fromAPFloat`. The methods `mkBoolean`, `mkBitvector` and `mkFloat` are now used instead.
- The names of the functions that convert BVs to FPs were swapped (`mkSBVtoFP`, `mkUBVtoFP`, `mkFPtoSBV`, `mkFPtoUBV`).
- Added a couple of comments in function calls.
Crosscheck encoding:
- Changed how constraints are encoded in the refutation manager so it doesn't start with (false OR ...). This change introduces one duplicated line (see file `BugReporterVisitors.cpp`, the `SMTConv::getRangeExpr is called twice, so I can remove this change if the duplication is a problem.
Reviewers: george.karpenkov, NoQ
Reviewed By: george.karpenkov
Subscribers: xazax.hun, szepet, a.sidorin, Szelethus
Differential Revision: https://reviews.llvm.org/D52365
llvm-svn: 343581
This is patch is a preparation for the proposed inclusion of macro expansions in the plist output.
Differential Revision: https://reviews.llvm.org/D52735
llvm-svn: 343511
Dumping graphs instead of opening them is often very useful,
e.g. for transfer or converting to SVG.
Basic sanity check for generated exploded graphs.
Differential Revision: https://reviews.llvm.org/D52637
llvm-svn: 343352
Commit r340984 causes a crash when a pointer to a completely unrelated type
UnrelatedT (eg., opaque struct pattern) is being casted from base class BaseT to
derived class DerivedT, which results in an ill-formed region
Derived{SymRegion{$<UnrelatedT x>}, DerivedT}.
Differential Revision: https://reviews.llvm.org/D52189
llvm-svn: 343051
Combine the two constructor overrides into a single ArrayRef constructor
to allow easier brace initializations and simplify how the respective field
is used internally.
Differential Revision: https://reviews.llvm.org/D51390
llvm-svn: 343037
Benjamin Kramer