Commit Graph

3116 Commits

Author SHA1 Message Date
Artem Dergachev a3b22da4e0 [CFG] Fix a flaky crash in CFGBlock::getLastCondition().
Using an end iterator of an empty CFG block was causing
a garbage pointer dereference.

Differential Revision: https://reviews.llvm.org/D69962
2019-11-21 21:55:58 -08:00
Artem Dergachev 0b58b80edb [analyzer] Fix Objective-C accessor body farms after 2073dd2d.
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
2019-11-21 18:59:46 -08:00
Tyker b0561b3346 [NFC] Refactor representation of materialized temporaries
Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63640#inline-612718

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: thakis, sammccall, ilya-biryukov, rnkovacs, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69360
2019-11-19 18:20:45 +01:00
Nico Weber c9276fbfdf Revert "[NFC] Refactor representation of materialized temporaries"
This reverts commit 08ea1ee2db.
It broke ./ClangdTests/FindExplicitReferencesTest.All
on the bots, see comments on https://reviews.llvm.org/D69360
2019-11-17 02:09:25 -05:00
Tyker 08ea1ee2db [NFC] Refactor representation of materialized temporaries
Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63640#inline-612718

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: rnkovacs, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69360
2019-11-16 17:56:09 +01:00
Reid Kleckner 979da9a4c3 Avoid including Builtins.h in Preprocessor.h
Builtins are rarely if ever accessed via the Preprocessor. They are
typically found on the ASTContext, so there should be no performance
penalty to using a pointer indirection to store the builtin context.
2019-11-15 16:45:16 -08:00
Adrian Prantl 2073dd2da7 Redeclare Objective-C property accessors inside the ObjCImplDecl in which they are synthesized.
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
2019-11-08 08:23:22 -08:00
Aaron Puchert ae3159e497 Thread safety analysis: Peel away NoOp implicit casts in initializers
Summary:
This happens when someone initializes a variable with guaranteed copy
elision and an added const qualifier. Fixes PR43826.

Reviewers: aaron.ballman, rsmith

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D69533
2019-10-30 00:37:32 +01:00
Richard Trieu 8b0d14a8f0 New tautological warning for bitwise-or with non-zero constant always true.
Taking a value and the bitwise-or it with a non-zero constant will always
result in a non-zero value. In a boolean context, this is always true.

if (x | 0x4) {}  // always true, intended '&'

This patch creates a new warning group -Wtautological-bitwise-compare for this
warning. It also moves in the existing tautological bitwise comparisons into
this group. A few other changes were needed to the CFGBuilder so that all bool
contexts would be checked. The warnings in -Wtautological-bitwise-compare will
be off by default due to using the CFG.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=42666
Differential Revision: https://reviews.llvm.org/D66046

llvm-svn: 375318
2019-10-19 00:57:23 +00:00
Artem Dergachev d325196f19 [analyzer] Display cast kinds in program point dumps.
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
2019-10-17 23:10:05 +00:00
Alexey Bataev 9c5d76ff4d [OPENMP]Dow not emit warnings for uninitialized loop counters.
In OpenMP constructs all counters are initialized and we should not emit
warnings about uninitialized privatized loop control variables.

llvm-svn: 375167
2019-10-17 20:35:08 +00:00
Erich Keane 5c2c60d2fc Teach CallGraph to look into Generic Lambdas.
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
2019-09-30 19:12:29 +00:00
Aaron Puchert 243058fff1 Don't install example analyzer plugins
Summary: Fixes PR43430.

Reviewers: hintonda, NoQ, Szelethus, lebedev.ri

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D68172

llvm-svn: 373148
2019-09-28 13:28:50 +00:00
Nicholas Allegra 695a8bd6a0 Revert r373034
It breaks the build on MSVC.

llvm-svn: 373039
2019-09-27 01:58:31 +00:00
Nicholas Allegra d5d62a99a9 [Consumed][NFC] Refactor handleCall to take function argument list.
Differential Revision: https://reviews.llvm.org/D67569

llvm-svn: 373034
2019-09-26 23:47:18 +00:00
Richard Trieu 4c05de8c1d Merge and improve code that detects same value in comparisons.
-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
2019-09-21 03:02:26 +00:00
Richard Trieu 6541c7988b Improve -Wtautological-overlap-compare
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
2019-09-21 02:37:10 +00:00
Nicholas Allegra 9dd57df26a [Consumed] Treat by-value class arguments as consuming by default, like rvalue refs.
Differential Revision: https://reviews.llvm.org/D67743

llvm-svn: 372361
2019-09-19 23:00:31 +00:00
Kristof Umann b8ac93c73b [analyzer] PR43102: Fix an assertion and an out-of-bounds error for diagnostic location construction
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
2019-09-18 22:24:26 +00:00
Kristof Umann f174670efa [CFG] Add dumps for CFGElement and CFGElementRef
Seems like we never had these, so here we go! I also did some refactoring as I
was chasing a bug unrelated to this revision.

Differential Revision: https://reviews.llvm.org/D66715

llvm-svn: 371765
2019-09-12 19:52:34 +00:00
Kristof Umann 72649423c0 [analyzer][NFC] Fix inconsistent references to checkers as "checks"
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
2019-09-12 19:09:24 +00:00
Artem Dergachev f0bb45fac3 [analyzer] NFC: Move PathDiagnostic classes to libAnalysis.
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
2019-09-11 20:54:27 +00:00
Artem Dergachev 2f169e7cdd [analyzer] NFC: Introduce sub-classes for path-sensitive and basic reports.
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
2019-09-09 20:34:40 +00:00
Artem Dergachev e5c0994ddf [CFG] Fix CFG for statement-expressions in return values.
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
2019-08-29 20:37:28 +00:00
Artem Dergachev 3517d10575 [analyzer] Fix more analyzer warnings on analyzer and libAnalysis.
llvm-svn: 370263
2019-08-28 21:19:58 +00:00
Artem Dergachev ead98ea3eb [CFG] Make representation of destructor calls more accurate.
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
2019-08-28 18:44:42 +00:00
Jan Kratochvil 95b5f42de8 [clang] Use the new Regex::isValid() with no parameter
Differential Revision: https://reviews.llvm.org/D66463

llvm-svn: 369397
2019-08-20 16:07:31 +00:00
Artem Dergachev 8cf3dfea54 [CallGraph] Take into accound calls that aren't within any function bodies.
This patch improves Clang call graph analysis by adding in expressions
that are not found in regular function bodies, such as default arguments
or member initializers.

Patch by Joshua Cranmer!

Differential Revision: https://reviews.llvm.org/D65453

llvm-svn: 369321
2019-08-20 02:22:37 +00:00
Jonas Devlieghere 2b3d49b610 [Clang] Migrate llvm::make_unique to std::make_unique
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
2019-08-14 23:04:18 +00:00
Kristof Umann 92541e359e [CFG] Introduce CFGElementRef, a wrapper that knows it's position in a CFGBlock
Previously, collecting CFGElements in a set was practially impossible, because
both CFGBlock::operator[] and both the iterators returned it by value. One
workaround would be to collect the iterators instead, but they don't really
capture the concept of an element, and elements from different iterator types are incomparable.

This patch introduces CFGElementRef, a wrapper around a (CFGBlock, Index) pair,
and a variety of new iterators and iterator ranges to solve this problem.

I guess you could say that this patch took a couple iterations to get right :^)

Differential Revision: https://reviews.llvm.org/D65196

llvm-svn: 368883
2019-08-14 17:05:55 +00:00
Kristof Umann dd53bdbfde [analyzer][CFG] Don't track the condition of asserts
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
2019-08-14 12:20:08 +00:00
Rui Ueyama 4d41c332ef Revert r367649: Improve raw_ostream so that you can "write" colors using operator<<
This reverts commit r367649 in an attempt to unbreak Windows bots.

llvm-svn: 367658
2019-08-02 07:22:34 +00:00
Rui Ueyama a52f982f1c Improve raw_ostream so that you can "write" colors using operator<<
1. raw_ostream supports ANSI colors so that you can write messages to
the termina with colors. Previously, in order to change and reset
color, you had to call `changeColor` and `resetColor` functions,
respectively.

So, if you print out "error: " in red, for example, you had to do
something like this:

  OS.changeColor(raw_ostream::RED);
  OS << "error: ";
  OS.resetColor();

With this patch, you can write the same code as follows:

  OS << raw_ostream::RED << "error: " << raw_ostream::RESET;

2. Add a boolean flag to raw_ostream so that you can disable colored
output. If you disable colors, changeColor, operator<<(Color),
resetColor and other color-related functions have no effect.

Most LLVM tools automatically prints out messages using colors, and
you can disable it by passing a flag such as `--disable-colors`.
This new flag makes it easy to write code that works that way.

Differential Revision: https://reviews.llvm.org/D65564

llvm-svn: 367649
2019-08-02 04:48:30 +00:00
Csaba Dabis 7740c6d643 [analyzer] StackFrameContext: Add NodeBuilderContext::blockCount() to its profile
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
2019-08-01 20:41:13 +00:00
Alexey Bataev 655cb4a2d7 [OPENMP]Add support for analysis of if clauses.
Summary:
Added support for analysis of if clauses in the OpenMP directives to be
able to check for the use of uninitialized variables.

Reviewers: NoQ

Subscribers: guansong, jfb, jdoerfert, caomhin, kkwli0, cfe-commits

Tags: clang

Differential Revision: https://reviews.llvm.org/D64646

llvm-svn: 366211
2019-07-16 14:51:46 +00:00
Rui Ueyama 49a3ad21d6 Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Artem Dergachev ed035ff826 [analyzer] exploded-graph-rewriter: Improve source location dumps.
- Correctly display macro expansion and spelling locations.
- Use the same procedure to display location context call site locations.
- Display statement IDs for program points.

llvm-svn: 365861
2019-07-12 02:10:33 +00:00
Alexey Bataev c2c21ef9d2 [OPENMP]Initial fix PR42392: Improve -Wuninitialized warnings for OpenMP programs.
Summary:
Some OpenMP clauses rely on the values of the variables. If the variable
is not initialized and used in OpenMP clauses that depend on the
variables values, it should be reported that the uninitialized variable
is used in the OpenMP clause expression.
This patch adds initial processing for uninitialized variables in OpenMP
constructs. Currently, it checks for use of the uninitialized variables
in the structured blocks.

Reviewers: NoQ, Szelethus, dcoughlin, xazax.hun, a.sidorin, george.karpenkov, szepet

Subscribers: rnkovacs, guansong, jfb, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64356

llvm-svn: 365786
2019-07-11 14:54:17 +00:00
Kristof Umann d5c9d9b682 [CFG] Add a new function to get the proper condition of a CFGBlock
getTerminatorCondition() returned a condition that may be outside of the
block, while the new function returns the proper one:

if (A && B && C) {}

Return C instead of A && B && C.

Differential Revision: https://reviews.llvm.org/D63538

llvm-svn: 365177
2019-07-05 09:52:00 +00:00
Tom Stellard 2e97d2aa1b cmake: Add CLANG_LINK_CLANG_DYLIB option
Summary:
Setting CLANG_LINK_CLANG_DYLIB=ON causes clang tools to link against
libclang_shared.so instead of the individual component libraries.

Reviewers: mgorny, beanz, smeenai, phosek, sylvestre.ledru

Subscribers: arphaman, cfe-commits, llvm-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63503

llvm-svn: 365092
2019-07-03 22:45:55 +00:00
Kristof Umann 9854d771bd Revert "[analyzer][CFG] Return the correct terminator condition"
This reverts commit 7a57118a6fcfa3770f984453543bbdfd0b233e84.

Causes a bunch of crashes, I need to time to evaluate this.

llvm-svn: 365037
2019-07-03 13:03:33 +00:00
Kristof Umann 00aab1d45e [analyzer][CFG] Return the correct terminator condition
For the following terminator statement:

if (A && B && C && D)
The built CFG is the following:

[B5 (ENTRY)]
  Succs (1): B4

[B1]
  1: 10
  2: j
  3: [B1.2] (ImplicitCastExpr, LValueToRValue, int)
  4: [B1.1] / [B1.3]
  5: int x = 10 / j;
  Preds (1): B2
  Succs (1): B0

[B2]
  1: C
  2: [B2.1] (ImplicitCastExpr, LValueToRValue, _Bool)
  T: if [B4.4] && [B3.2] && [B2.2]
  Preds (1): B3
  Succs (2): B1 B0

[B3]
  1: B
  2: [B3.1] (ImplicitCastExpr, LValueToRValue, _Bool)
  T: [B4.4] && [B3.2] && ...
  Preds (1): B4
  Succs (2): B2 B0

[B4]
  1: 0
  2: int j = 0;
  3: A
  4: [B4.3] (ImplicitCastExpr, LValueToRValue, _Bool)
  T: [B4.4] && ...
  Preds (1): B5
  Succs (2): B3 B0

[B0 (EXIT)]
  Preds (4): B1 B2 B3 B4

However, even though the path of execution in B2 only depends on C's value,
CFGBlock::getCondition() would return the entire condition (A && B && C). For
B3, it would return A && B. I changed this the actual condition.

Differential Revision: https://reviews.llvm.org/D63538

llvm-svn: 365036
2019-07-03 12:53:19 +00:00
Kristof Umann b069bbf510 Make a buildbot using a buggy gcc happy
When specializing a template in a namespace, it has to be in a namespace
block, else gcc will get confused. Hopefully this fixes the issue.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480

llvm-svn: 365030
2019-07-03 12:06:10 +00:00
Kristof Umann c4b89fec5f Specialize an anchor() function in the correct namespace
llvm-svn: 365029
2019-07-03 11:54:47 +00:00
Kristof Umann 71a9dc39e4 [analyzer][Dominator] Add post dominators to CFG + a new debug checker
Transform clang::DominatorTree to be able to also calculate post dominators.

* Tidy up the documentation
* Make it clang::DominatorTree template class (similarly to how
  llvm::DominatorTreeBase works), rename it to clang::CFGDominatorTreeImpl
* Clang's dominator tree is now called clang::CFGDomTree
* Clang's brand new post dominator tree is called clang::CFGPostDomTree
* Add a lot of asserts to the dump() function
* Create a new checker to test the functionality

Differential Revision: https://reviews.llvm.org/D62551

llvm-svn: 365028
2019-07-03 11:39:12 +00:00
Csaba Dabis 3a4a60eb6a [analyzer] print() JSONify: ProgramPoint revision
Summary: Now we also print out the filename with its path.

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/D63438

llvm-svn: 364197
2019-06-24 16:19:39 +00:00
Artem Dergachev f9f6cdb1a8 [analyzer] Fix JSON dumps for location contexts.
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
2019-06-19 23:33:48 +00:00
Artem Dergachev b03854f8e8 [analyzer] RetainCount: Add support for OSRequiredCast().
It's a new API for custom RTTI in Apple IOKit/DriverKit framework that is
similar to OSDynamicCast() that's already supported, but crashes instead of
returning null (and therefore causing UB when the cast fails unexpectedly).
Kind of like cast_or_null<> as opposed to dyn_cast_or_null<> in LLVM's RTTI.

Historically, RetainCountChecker was responsible for modeling OSDynamicCast.
This is simply an extension of the same functionality.

Differential Revision: https://reviews.llvm.org/D63117

llvm-svn: 363891
2019-06-19 23:33:34 +00:00
Csaba Dabis fa880e6114 [analyzer] ProgramPoint: more explicit printJson()
Summary: Now we print out every possible kinds of ProgramPoints.

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/D62946

llvm-svn: 363187
2019-06-12 18:24:02 +00:00
Richard Smith 1bbad59379 For DR712: store on a MemberExpr whether it constitutes an odr-use.
llvm-svn: 363087
2019-06-11 17:50:36 +00:00