Container operations such as `push_back()`, `pop_front()`
etc. increment and decrement the abstract begin and end
symbols of containers. This patch introduces note tags
to `ContainerModeling` to track these changes. This helps
the user to better identify the source of errors related
to containers and iterators.
Differential Revision: https://reviews.llvm.org/D73720
Upon calling one of the functions `std::advance()`, `std::prev()` and
`std::next()` iterators could get out of their valid range which leads
to undefined behavior. If all these funcions are inlined together with
the functions they call internally (e.g. `__advance()` called by
`std::advance()` in some implementations) the error is detected by
`IteratorRangeChecker` but the bug location is inside the STL
implementation. Even worse, if the budget runs out and one of the calls
is not inlined the bug remains undetected. This patch fixes this
behavior: all the bugs are detected at the point of the STL function
invocation.
Differential Revision: https://reviews.llvm.org/D76379
Whenever the analyzer budget runs out just at the point where
`std::advance()`, `std::prev()` or `std::next()` is invoked the function
are not inlined. This results in strange behavior such as
`std::prev(v.end())` equals `v.end()`. To prevent this model these
functions if they were not inlined. It may also happend that although
`std::advance()` is inlined but a function it calls inside (e.g.
`__advance()` in some implementations) is not. This case is also handled
in this patch.
Differential Revision: https://reviews.llvm.org/D76361
Discovered by a downstream user, we found that the CallGraph ignores
callees unless they are defined. This seems foolish, and prevents
combining the report with other reports to create unified reports.
Additionally, declarations contain information that is likely useful to
consumers of the CallGraph.
This patch implements this by splitting the includeInGraph function into
two versions, the current one plus one that is for callees only. The
only difference currently is that includeInGraph checks for a body, then
calls includeCalleeInGraph.
Differential Revision: https://reviews.llvm.org/D76435
Summary:
Outputs from an asm goto block cannot be used on the indirect branch.
It's not supported and may result in invalid code generation.
Reviewers: jyknight, nickdesaulniers, hfinkel
Reviewed By: nickdesaulniers
Subscribers: martong, cfe-commits, rnk, craig.topper, hiraditya, rsmith
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71314
Summary:
According to documentations, after an `fclose` call any other stream
operations cause undefined behaviour, regardless if the close failed
or not.
This change adds the check for the opened state before all other
(applicable) operations.
Reviewers: Szelethus
Reviewed By: Szelethus
Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, gamesh411, Charusso, martong, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75614
The output of subprocess.check_output is decode()'d through the rest of
this python program, but one appears to have been missed for the output
of the call to "clang -print-file-name=include".
On Windows, with Python 3.6, this leads to the 'args' array being a mix of
bytes and strings, which causes exceptions later down the line.
I can't easily test with python2 on Windows, but python2 on Ubuntu 18.04
was happy with this change.
Summary: The new way of checking fix-its is `%check_analyzer_fixit`.
Reviewed By: NoQ, Szelethus, xazax.hun
Differential Revision: https://reviews.llvm.org/D73729
Summary:
This patch introduces a way to apply the fix-its by the Analyzer:
`-analyzer-config apply-fixits=true`.
The fix-its should be testable, therefore I have copied the well-tested
`check_clang_tidy.py` script. The idea is that the Analyzer's workflow
is different so it would be very difficult to use only one script for
both Tidy and the Analyzer, the script would diverge a lot.
Example test: `// RUN: %check-analyzer-fixit %s %t -analyzer-checker=core`
When the copy-paste happened the original authors were:
@alexfh, @zinovy.nis, @JonasToth, @hokein, @gribozavr, @lebedev.ri
Reviewed By: NoQ, alexfh, zinovy.nis
Differential Revision: https://reviews.llvm.org/D69746
Summary:
This patch introduces the `clang_analyzer_isTainted` expression inspection
check for checking taint.
Using this we could query the analyzer whether the expression used as the
argument is tainted or not. This would be useful in tests, where we don't want
to issue warning for all tainted expressions in a given file
(like the `debug.TaintTest` would do) but only for certain expressions.
Example usage:
```lang=c++
int read_integer() {
int n;
clang_analyzer_isTainted(n); // expected-warning{{NO}}
scanf("%d", &n);
clang_analyzer_isTainted(n); // expected-warning{{YES}}
clang_analyzer_isTainted(n + 2); // expected-warning{{YES}}
clang_analyzer_isTainted(n > 0); // expected-warning{{YES}}
int next_tainted_value = n; // no-warning
return n;
}
```
Reviewers: NoQ, Szelethus, baloghadamsoftware, xazax.hun, boga95
Reviewed By: Szelethus
Subscribers: martong, rnkovacs, whisperity, xazax.hun,
baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, donat.nagy,
Charusso, cfe-commits, boga95, dkrupp, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74131
Summary:
Right now we annotate C++'s `operator new` with `noalias` attribute,
which very much is healthy for optimizations.
However as per [[ http://eel.is/c++draft/basic.stc.dynamic.allocation | `[basic.stc.dynamic.allocation]` ]],
there are more promises on global `operator new`, namely:
* non-`std::nothrow_t` `operator new` *never* returns `nullptr`
* If `std::align_val_t align` parameter is taken, the pointer will also be `align`-aligned
* ~~global `operator new`-returned pointer is `__STDCPP_DEFAULT_NEW_ALIGNMENT__`-aligned ~~ It's more caveated than that.
Supplying this information may not cause immediate landslide effects
on any specific benchmarks, but it for sure will be healthy for optimizer
in the sense that the IR will better reflect the guarantees provided in the source code.
The caveat is `-fno-assume-sane-operator-new`, which currently prevents emitting `noalias`
attribute, and is automatically passed by Sanitizers ([[ https://bugs.llvm.org/show_bug.cgi?id=16386 | PR16386 ]]) - should it also cover these attributes?
The problem is that the flag is back-end-specific, as seen in `test/Modules/explicit-build-flags.cpp`.
But while it is okay to add `noalias` metadata in backend, we really should be adding at least
the alignment metadata to the AST, since that allows us to perform sema checks on it.
Reviewers: erichkeane, rjmccall, jdoerfert, eugenis, rsmith
Reviewed By: rsmith
Subscribers: xbolva00, jrtc27, atanasyan, nlopes, cfe-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D73380
So far we've been dropping coverage every time we've encountered
a CXXInheritedCtorInitExpr. This patch attempts to add some
initial support for it.
Constructors for arguments of a CXXInheritedCtorInitExpr are still
not fully supported.
Differential Revision: https://reviews.llvm.org/D74735
Exactly what it says on the tin! I decided not to merge this with the patch that
changes all these to a CallDescriptionMap object, so the patch is that much more
trivial.
Differential Revision: https://reviews.llvm.org/D68163
Currently, using negative numbers in iterator operations (additions and
subractions) results in advancements with huge positive numbers due to
an error. This patch fixes it.
Differential Revision: https://reviews.llvm.org/D74760
Summary:
Clang's "asm goto" feature didn't initially support outputs constraints. That
was the same behavior as gcc's implementation. The decision by gcc not to
support outputs was based on a restriction in their IR regarding terminators.
LLVM doesn't restrict terminators from returning values (e.g. 'invoke'), so
it made sense to support this feature.
Output values are valid only on the 'fallthrough' path. If an output value's used
on an indirect branch, then it's 'poisoned'.
In theory, outputs *could* be valid on the 'indirect' paths, but it's very
difficult to guarantee that the original semantics would be retained. E.g.
because indirect labels could be used as data, we wouldn't be able to split
critical edges in situations where two 'callbr' instructions have the same
indirect label, because the indirect branch's destination would no longer be
the same.
Reviewers: jyknight, nickdesaulniers, hfinkel
Reviewed By: jyknight, nickdesaulniers
Subscribers: MaskRay, rsmith, hiraditya, llvm-commits, cfe-commits, craig.topper, rnk
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D69876
Summary:
This patch introduces a new checker:
`alpha.security.cert.pos.34c`
This checker is implemented based on the following rule:
https://wiki.sei.cmu.edu/confluence/x/6NYxBQ
The check warns if `putenv` function is
called with automatic storage variable as an argument.
Differential Revision: https://reviews.llvm.org/D71433
This is useful for performing custom build system integration that works by appending '--analyze --analyzer-output html' to all clang build commands.
For such users there is now still a way to have the fancy index.html file
in the output.
Differential Revision: https://reviews.llvm.org/D74467
In the path-sensitive vfork() checker that keeps a list of operations
allowed after a successful vfork(), unforget to include execve() in the list.
Patch by Jan Včelák!
Differential Revision: https://reviews.llvm.org/D73629
Converting a pointer to an integer whose result cannot represented in the
integer type is undefined behavior is C and prohibited in C++. C++ already
has a diagnostic when casting. This adds a diagnostic for C.
Since this diagnostic uses the range of the conversion it also modifies
int-to-pointer-cast diagnostic to use a range.
Fixes PR8718: No warning on casting between pointer and non-pointer-sized int
Differential Revision: https://reviews.llvm.org/D72231
Summary:
Both EOF and the max value of unsigned char is platform dependent. In this
patch we try our best to deduce the value of EOF from the Preprocessor,
if we can't we fall back to -1.
Reviewers: Szelethus, NoQ
Subscribers: whisperity, xazax.hun, kristof.beyls, baloghadamsoftware, szepet, rnkovacs, a.sidorin, mikhail.ramalh
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74473
Summary:
Due to a recent (but retroactive) C++ rule change, only sufficiently
C-compatible classes are permitted to be given a typedef name for
linkage purposes. Add an enabled-by-default warning for these cases, and
rephrase our existing error for the case where we encounter the typedef
name for linkage after we've already computed and used a wrong linkage
in terms of the new rule.
Reviewers: rjmccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74103
STL Algorithms are usually implemented in a tricky for performance
reasons which is too complicated for the analyzer. Furthermore inlining
them is costly. Instead of inlining we should model their behavior
according to the specifications.
This patch is the first step towards STL Algorithm modeling. It models
all the `find()`-like functions in a simple way: the result is either
found or not. In the future it can be extended to only return success if
container modeling is also extended in a way the it keeps track of
trivial insertions and deletions.
Differential Revision: https://reviews.llvm.org/D70818
The tool is now looked for in the source directory rather than in the
install directory, which should exclude the problems with not being able
to find it.
The tests still aren't being run on Windows, but they hopefully will run
on other platforms that have shell, which hopefully also means Perl.
Differential Revision: https://reviews.llvm.org/D69781
Iterator modeling depends on container modeling,
but not vice versa. This enables the possibility
to arrange these two modeling checkers into
separate layers.
There are several advantages for doing this: the
first one is that this way we can keep the
respective modeling checkers moderately simple
and small. Furthermore, this enables creation of
checkers on container operations which only
depend on the container modeling. Thus iterator
modeling can be disabled together with the
iterator checkers if they are not needed.
Since many container operations also affect
iterators, container modeling also uses the
iterator library: it creates iterator positions
upon calling the `begin()` or `end()` method of
a containter (but propagation of the abstract
position is left to the iterator modeling),
shifts or invalidates iterators according to the
rules upon calling a container modifier and
rebinds the iterator to a new container upon
`std::move()`.
Iterator modeling propagates the abstract
iterator position, handles the relations between
iterator positions and models iterator
operations such as increments and decrements.
Differential Revision: https://reviews.llvm.org/D73547
These are mostly trivial additions as both of them are reusing existing
PThreadLockChecker logic. I only needed to add the list of functions to
check and do some plumbing to make sure that we display the right
checker name in the diagnostic.
Differential Revision: https://reviews.llvm.org/D73376
Summary:
This checker verifies if default placement new is provided with pointers
to sufficient storage capacity.
Noncompliant Code Example:
#include <new>
void f() {
short s;
long *lp = ::new (&s) long;
}
Based on SEI CERT rule MEM54-CPP
https://wiki.sei.cmu.edu/confluence/display/cplusplus/MEM54-CPP.+Provide+placement+new+with+properly+aligned+pointe
This patch does not implement checking of the alignment.
Reviewers: NoQ, xazax.hun
Subscribers: mgorny, whisperity, xazax.hun, baloghadamsoftware, szepet,
rnkovacs, a.sidorin, mikhail.ramalho, donat
Tags: #clang
Differential Revision: https://reviews.llvm.org/D71612
Method '-[NSCoder decodeValueOfObjCType:at:]' is not only deprecated
but also a security hazard, hence a loud check.
Differential Revision: https://reviews.llvm.org/D71728
MallocChecker warns when memory is passed into -[NSData initWithBytesNoCopy]
but isn't allocated by malloc(), because it will be deallocated by free().
However, initWithBytesNoCopy has an overload that takes an arbitrary block
for deallocating the object. If such overload is used, it is no longer
necessary to make sure that the memory is allocated by malloc().
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
This patch introduces the namespaces for the configured functions and
also enables the use of the member functions.
I added an optional Scope field for every configured function. Functions
without Scope match for every function regardless of the namespace.
Functions with Scope will match if the full name of the function starts
with the Scope.
Multiple functions can exist with the same name.
Differential Revision: https://reviews.llvm.org/D70878
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
The checker was trying to analyze the body of every method in Objective-C
@implementation clause but the sythesized accessor stubs that were introduced
into it by 2073dd2d have no bodies.
While analyzing code `memcmp(a, NULL, n);', where `a' has an unconstrained
symbolic value, the analyzer was emitting a warning about the *first* argument
being a null pointer, even though we'd rather have it warn about the *second*
argument.
This happens because CStringChecker first checks whether the two argument
buffers are in fact the same buffer, in order to take the fast path.
This boils down to assuming `a == NULL' to true. Then the subsequent check
for null pointer argument "discovers" that `a' is null.
Don't take the fast path unless we are *sure* that the buffers are the same.
Otherwise proceed as normal.
Differential Revision: https://reviews.llvm.org/D71322
Sometimes the return value of a comparison operator call is
`UnkownVal`. Since no assumptions can be made on `UnknownVal`,
this leeds to keeping impossible execution paths in the
exploded graph resulting in poor performance and false
positives. To overcome this we replace unknown results of
iterator comparisons by conjured symbols.
Differential Revision: https://reviews.llvm.org/D70244
Debugging the Iterator Modeling checker or any of the iterator checkers
is difficult without being able to see the relations between the
iterator variables and their abstract positions, as well as the abstract
symbols denoting the begin and the end of the container.
This patch adds the checker-specific part of the Program State printing
to the Iterator Modeling checker.
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 crash when constructing a body farm for accessors of a property
that is declared and @synthesize'd in different (but related) interfaces
with the explicit ivar syntax.
This is a follow-up for 0b58b80e.
This patch is the last of the series of patches which allow the user to
annotate their functions with taint propagation rules.
I implemented the use of the configured filtering functions. These
functions can remove taintedness from the symbols which are passed at
the specified arguments to the filters.
Differential Revision: https://reviews.llvm.org/D59516
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
Push the test separately ahead of time in order to find out whether
our Memory Sanitizer bots will be able to find the problem.
If not, I'll add a much more expensive test that repeats the current
test multiple times in order to show up on normal buildbots.
I really apologize for the potential temporary inconvenience!
I'll commit the fix as soon as I get the signal.
Differential Revision: https://reviews.llvm.org/D69962
The recently committed debug.IteratorDebugging checker enables
standalone white-box testing of the modelling of containers and
iterators. For the three checkers based on iterator modelling only
simple tests are needed.
Differential Revision: https://reviews.llvm.org/D70123
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
For white-box testing correct container and iterator modelling it is essential
to access the internal data structures stored for container and iterators. This
patch introduces a simple debug checkers called debug.IteratorDebugging to
achieve this.
Differential Revision: https://reviews.llvm.org/D67156
Namely, for the following items:
- Handle constructors within new[];
- Handle constructors for default arguments.
Update the open projects page with a link to the newly added tests
and more hints for potential contributors.
Patch by Daniel Krupp!
Differential Revision: https://reviews.llvm.org/D69308
- Fix false positive reports of strlcat.
- The return value of strlcat and strlcpy is now correctly calculated.
- The resulting string length of strlcat and strlcpy is now correctly
calculated.
Patch by Daniel Krupp!
Differential Revision: https://reviews.llvm.org/D66049
The static analyzer's scan-build script is critical infrastructure but
is not well tested. To start to address this, add a new test directory under
tests/Analysis for scan-build lit tests and seed it with several tests. The
goal is that future scan-build changes will be accompanied by corresponding
tests.
Differential Revision: https://reviews.llvm.org/D69781
Summary:
Recognization of function names is done now with the CallDescription
class instead of using IdentifierInfo. This means function name and
argument count is compared too.
A new check for filtering not global-C-functions was added.
Test was updated.
Reviewers: Szelethus, NoQ, baloghadamsoftware, Charusso
Reviewed By: Szelethus, NoQ, Charusso
Subscribers: rnkovacs, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, donat.nagy, Charusso, dkrupp, Szelethus, gamesh411, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67706
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
Because cast expressions have their own hierarchy, it's extremely useful
to have some information about what kind of casts are we dealing with.
llvm-svn: 375185
In OpenMP constructs all counters are initialized and we should not emit
warnings about uninitialized privatized loop control variables.
llvm-svn: 375167
The goal is to have 100% fidelity in clang-scan-deps behavior when
--analyze is present in compilation command.
At the same time I don't want to break clang-tidy which expects
__static_analyzer__ macro defined as built-in.
I introduce new cc1 options (-setup-static-analyzer) that controls
the macro definition and is conditionally set in driver.
Differential Revision: https://reviews.llvm.org/D68093
llvm-svn: 374815
CallGraph visited LambdaExpr by getting the Call Operator from
CXXRecordDecl (LambdaExpr::getCallOperator calls
CXXRecordDecl::getLambdaCallOperator), which replaced generic lambda
call operators with the non-instantiated FunctionDecl. The result was
that the CallGraph would only pick up non-dependent calls.
This patch does a few things:
1- Extend CXXRecordDecl to have a getDependentLambdaCallOperator, which
will get the FunctionTemplateDecl, rather than immediately getting the
TemplateDecl.
2- Define getLambdaCallOperator and getDependentLambdaCallOperator in
terms of a common function.
3- Extend LambdaExpr with a getDependentCallOperator, which just calls
the above function.
4- Changes CallGraph to handle Generic LambdaExprs.
llvm-svn: 373247
-Wtautological-overlap-compare and self-comparison from -Wtautological-compare
relay on detecting the same operand in different locations. Previously, each
warning had it's own operand checker. Now, both are merged together into
one function that each can call. The function also now looks through member
access and array accesses.
Differential Revision: https://reviews.llvm.org/D66045
llvm-svn: 372453
Allow this warning to detect a larger number of constant values, including
negative numbers, and handle non-int types better.
Differential Revision: https://reviews.llvm.org/D66044
llvm-svn: 372448
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
'-Xclang -triple' doesn't seem to override the default target triple
as reliably as '--target'. This leads to test failing due to
platform-specific checks getting unexpectedly enabled.
llvm-svn: 371781
Short and sweet. Whenever I use -analyzer-list-enabled-checkers, I'm only
interested about the configuration, not about the analysis.
Differential Revision: https://reviews.llvm.org/D66714
llvm-svn: 371756
This reverts r371497 (git commit 3d7e9ab7b9)
Reorder `not` with `env` in these two tests so they pass:
Driver/rewrite-map-in-diagnostics.c
Index/crash-recovery-modules.m.
This will not be necessary after D66531 lands.
llvm-svn: 371552
I see in the history for some of these tests REQUIRES:shell was used as
a way to disable tests on Windows because they are flaky there. I tried
not to re-enable such tests, but it's possible that I missed some and
this will re-enable flaky tests on Windows. If so, we should disable
them with UNSUPPORTED:system-windows and add a comment that they are
flaky there. So far as I can tell, the lit internal shell is capable of
running all of these tests, and we shouldn't use REQUIRES:shell as a
proxy for Windows.
llvm-svn: 371478
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
There are some functions which can't be given a null pointer as parameter either
because it has a nonnull attribute or it is declared to have undefined behavior
(e.g. strcmp()). Sometimes it is hard to determine from the checker message
which parameter is null at the invocation, so now this information is included
in the message.
This commit fixes https://bugs.llvm.org/show_bug.cgi?id=39358
Reviewed By: NoQ, Szelethus, whisperity
Patch by Tibor Brunner!
Differential Revision: https://reviews.llvm.org/D66333
llvm-svn: 370798
Enables the users to specify an optional flag which would warn for more dead
stores.
Previously it ignored if the dead store happened e.g. in an if condition.
if ((X = generate())) { // dead store to X
}
This patch introduces the `WarnForDeadNestedAssignments` option to the checker,
which is `false` by default - so this change would not affect any previous
users.
I have updated the code, tests and the docs as well. If I missed something, tell
me.
I also ran the analysis on Clang which generated 14 more reports compared to the
unmodified version. All of them seemed reasonable for me.
Related previous patches:
rGf224820b45c6847b91071da8d7ade59f373b96f3
Reviewers: NoQ, krememek, Szelethus, baloghadamsoftware
Reviewed By: Szelethus
Patch by Balázs Benics!
Differential Revision: https://reviews.llvm.org/D66733
llvm-svn: 370767
initializers.
This has some interesting interactions with our existing extensions to
support C99 designated initializers as an extension in C++. Those are
resolved as follows:
* We continue to permit the full breadth of C99 designated initializers
in C++, with the exception that we disallow a partial overwrite of an
initializer with a non-trivially-destructible type. (Full overwrite
is OK, because we won't run the first initializer at all.)
* The C99 extensions are disallowed in SFINAE contexts and during
overload resolution, where they could change the meaning of valid
programs.
* C++20 disallows reordering of initializers. We only check for that for
the simple cases that the C++20 rules permit (designators of the form
'.field_name =' and continue to allow reordering in other cases).
It would be nice to improve this behavior in future.
* All C99 designated initializer extensions produce a warning by
default in C++20 mode. People are going to learn the C++ rules based
on what Clang diagnoses, so it's important we diagnose these properly
by default.
* In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and
so still diagnose C99 extensions as described above. We continue to
accept designated C++20-compatible initializers in C++ <= 17 silently
by default (but naturally still reject under -pedantic-errors).
This is not a complete implementation of P0329R4. In particular, that
paper introduces new non-C99-compatible syntax { .field { init } }, and
we do not support that yet.
This is based on a previous patch by Don Hinton, though I've made
substantial changes when addressing the above interactions.
Differential Revision: https://reviews.llvm.org/D59754
llvm-svn: 370544
We're building the CFG from bottom to top, so when the return-value expression
has a non-trivial CFG on its own, we need to continue building from the entry
to the return-value expression CFG rather than from the block to which
we've just appended the return statement.
Fixes a false positive warning "control may reach end of non-void function".
llvm-svn: 370406
Range errors (dereferencing or incrementing the past-the-end iterator or
decrementing the iterator of the first element of the range) and access of
invalidated iterators lead to undefined behavior. There is no point to
continue the analysis after such an error on the same execution path, but
terminate it by a sink node (fatal error). This also improves the
performance and helps avoiding double reports (e.g. in case of nested
iterators).
Differential Revision: https://reviews.llvm.org/D62893
llvm-svn: 370314
Respect C++17 copy elision; previously it would generate destructor calls
for elided temporaries, including in initialization and return statements.
Don't generate duplicate destructor calls for statement expressions.
Fix destructors in initialization lists and comma operators.
Improve printing of implicit destructors.
Patch by Nicholas Allegra!
Differential Revision: https://reviews.llvm.org/D66404
llvm-svn: 370247
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
Summary:
Added basic analysis of map clauses. Only map clauses with to and tofrom
map type must be analyzed since all other map types (alloc, delete, etc.) do not require to use the value of the initial variable, instead they create the new copy of the variable.
Reviewers: NoQ
Subscribers: guansong, cfe-commits, kkwli0, caomhin
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66668
llvm-svn: 370214
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
There are numorous flaws about the name conflict handling, this patch
attempts fixes them. Changes in details:
* HandleNameConflict return with a false DeclarationName
Hitherto we effectively never returned with a NameConflict error, even
if the preceding StructuralMatch indicated a conflict.
Because we just simply returned with the parameter `Name` in
HandleNameConflict and that name is almost always `true` when converted to
`bool`.
* Add tests which indicate wrong NameConflict handling
* Add to ConflictingDecls only if decl kind is different
Note, we might not indicate an ODR error when there is an existing record decl
and a enum is imported with same name. But there are other cases. E.g. think
about the case when we import a FunctionTemplateDecl with name f and we found a
simple FunctionDecl with name f. They overload. Or in case of a
ClassTemplateDecl and CXXRecordDecl, the CXXRecordDecl could be the 'templated'
class, so it would be false to report error. So I think we should report a
name conflict error only when we are 100% sure of that. That is why I think it
should be a general pattern to report the error only if the kind is the same.
* Fix failing ctu test with EnumConstandDecl
In ctu-main.c we have the enum class 'A' which brings in the enum
constant 'x' with value 0 into the global namespace.
In ctu-other.c we had the enum class 'B' which brought in the same name
('x') as an enum constant but with a different enum value (42). This is clearly
an ODR violation in the global namespace. The solution was to rename the
second enum constant.
* Introduce ODR handling strategies
Reviewers: a_sidorin, shafik
Differential Revision: https://reviews.llvm.org/D59692
llvm-svn: 370045
Summary: EnumCastOutOfRangeChecker should not perform enum range checks on LValueToRValue casts, since this type of cast does not actually change the underlying type. Performing the unnecessary check actually triggered an assertion failure deeper in EnumCastOutOfRange for certain input (which is captured in the accompanying test code).
Reviewers: #clang, Szelethus, gamesh411, NoQ
Reviewed By: Szelethus, gamesh411, NoQ
Subscribers: NoQ, gamesh411, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, donat.nagy, dkrupp, Charusso, bjope, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66014
llvm-svn: 369760
Our SVal hierarchy doesn't allow modeling pointer casts as no-op. The
pointer type is instead encoded into the pointer object. Defer to our
usual pointer casting facility, SValBuilder::evalBinOp().
Fixes a crash.
llvm-svn: 369729
This patch concludes my GSoC'19 project by enabling track-conditions by default.
Differential Revision: https://reviews.llvm.org/D66381
llvm-svn: 369616
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
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
Adam Balogh