Commit Graph

3017 Commits

Author SHA1 Message Date
Kristof Umann a3f7b58742 [analyzer][UninitializedObjectChecker] New flag to turn off dereferencing
Even for a checker being in alpha, some reports about pointees held so little
value to the user that it's safer to disable pointer/reference chasing for now.
It can be enabled with a new flag, in which case checker should function as it
has always been. This can be set with `CheckPointeeInitialization`.

Differential Revision: https://reviews.llvm.org/D49438

llvm-svn: 339135
2018-08-07 12:55:26 +00:00
Artem Dergachev afdce6684e [analyzer] pr37204: Take signedness into account in getTruthValue().
It now actually produces a signed APSInt when the QualType passed into it is
signed, which is what any caller would expect.

Fixes a couple of crashes.

Differential Revision: https://reviews.llvm.org/D50363

llvm-svn: 339088
2018-08-07 02:27:38 +00:00
Artem Dergachev 5a5b867422 [analyzer] NFC: Document that we support implicit argument constructors.
The change in the AST in r338135 caused us to accidentally support
inlining constructors of operator implicit arguments. Previously they were
hard to support because they were treated as arguments in expressions
but not in declarations, but now they can be transparently treated as
simple temporaries.

Add tests and comments to explain how it now works.

Differential Revision: https://reviews.llvm.org/D49627

llvm-svn: 339087
2018-08-07 02:22:59 +00:00
George Karpenkov 09c31b1c99 [analyzer] Do not crash in NoStoreFuncVisitor notes if an unexpected region is found.
Just do not generate the note at all in that case.

llvm-svn: 338935
2018-08-03 23:19:07 +00:00
Reka Kovacs bfd9cfdeeb [analyzer] Add test for a crash fixed in r338775.
Do not crash if a CXXRecordDecl cannot be obtained for an object.

Special thanks for the reproduction to Alexander Kornienko.

llvm-svn: 338918
2018-08-03 20:42:02 +00:00
Reka Kovacs 122171e235 [analyzer] Detect pointers escaped after ReturnStmt execution in MallocChecker.
Objects local to a function are destroyed right after the statement returning
(part of) them is executed in the analyzer. This patch enables MallocChecker to
warn in these cases.

Differential Revision: https://reviews.llvm.org/D49361

llvm-svn: 338780
2018-08-02 23:02:08 +00:00
Reka Kovacs 38679fd630 [analyzer] Obtain a ReturnStmt from a CFGAutomaticObjDtor.
The CoreEngine only gives us a ReturnStmt if the last element in the
CFGBlock is a CFGStmt, otherwise the ReturnStmt is nullptr.
This patch adds support for the case when the last element is a
CFGAutomaticObjDtor, by returning its TriggerStmt as a ReturnStmt.

Differential Revision: https://reviews.llvm.org/D49811

llvm-svn: 338777
2018-08-02 22:31:03 +00:00
George Karpenkov 61ac05c57e [analyzer] Fix tests.
llvm-svn: 338756
2018-08-02 18:41:25 +00:00
George Karpenkov 1d08c51ee5 [analyzer] Extend NoStoreFuncVisitor to follow fields.
rdar://39701823

Differential Revision: https://reviews.llvm.org/D49901

llvm-svn: 338667
2018-08-02 02:02:40 +00:00
Artem Dergachev 67d393f3d1 [analyzer] Fix eliding the same destructor twice due to buggy default arguments.
Because of incomplete support for CXXDefaultArgExpr, we cannot yet commit to
asserting that the same destructor won't be elided twice.

Suppress the assertion failure for now. Proper support is still an open problem.

Differential Revision: https://reviews.llvm.org/D49213

llvm-svn: 338441
2018-07-31 21:17:40 +00:00
Artem Dergachev a657a32cc8 [CFG] [analyzer] Implement function argument construction contexts.
In r330377 and r338425 we have already identified what constitutes function
argument constructors and added stubs in order to prevent confusing them
with other temporary object constructors.

Now we implement a ConstructionContext sub-class to carry all the necessary
information about the construction site, namely call expression and argument
index.

On the analyzer side, the patch interacts with the recently implemented
pre-C++17 copy elision support in an interesting manner. If on the CFG side we
didn't find a construction context for the elidable constructor, we build
the CFG as if the elidable constructor is not elided, and the non-elided
constructor within it is a simple temporary. But the same problem may occur
in the analyzer: if the elidable constructor has a construction context but
the analyzer doesn't implement such context yet, the analyzer should also
try to skip copy elision and still inline the non-elided temporary constructor.
This was implemented by adding a "roll back" mechanism: when elision fails,
roll back the changes and proceed as if it's a simple temporary. The approach
is wonky, but i'm fine with that as long as it's merely a defensive mechanism
that should eventually go away once all construction contexts become supported.

Differential Revision: https://reviews.llvm.org/D48681.

llvm-svn: 338436
2018-07-31 20:45:53 +00:00
Reka Kovacs bb1078ad85 [analyzer] Move InnerPointerChecker out of alpha.
Differential Revision: https://reviews.llvm.org/D49058

llvm-svn: 338433
2018-07-31 20:27:11 +00:00
Artem Dergachev e1f3062100 [CFG] [analyzer] Add construction contexts for returning C++ objects in ObjC++.
Like any normal funciton, Objective-C message can return a C++ object
in Objective-C++. Such object would require a construction context.

This patch, therefore, is an extension of r327343 onto Objective-C++.

Differential Revision: https://reviews.llvm.org/D48608

llvm-svn: 338426
2018-07-31 19:46:14 +00:00
Artem Dergachev bd880fe1c1 [CFG] [analyzer] Add stubs for constructor and message argument constructors.
CFG now correctly identifies construction context for temporaries constructed
for the purpose of passing into a function as an argument.

Such context is still not fully implemented because the information it provides
is not rich enough: it doens't contain information about argument index.
It will be addresssed later.

This patch is an extension of r330377 to C++ construct-expressions and
Objective-C message expressions which aren't call-expressions but require
similar handling. C++ new-expressions with placement arguments still remain to
be handled.

Differential Revision: https://reviews.llvm.org/D49826

llvm-svn: 338425
2018-07-31 19:39:37 +00:00
Artem Dergachev 05220a900c [analyzer] Don't try to simplify mixed Loc/NonLoc expressions.
This fix is similar to r337769 and addresses a regression caused by r337167.

When an operation between a nonloc::LocAsInteger and a non-pointer symbol
is performed, the LocAsInteger-specific part of information is lost.
When the non-pointer symbol is collapsing into a constant, we cannot easily
re-evaluate the result, because we need to recover the missing
LocAsInteger-specific information (eg., integer type, or the very fact that
this pointer was at some point converted to an integer).

Add one more defensive check to prevent crashes on trying to simplify a
SymSymExpr with different Loc-ness of operands.

Differential Revision: 

llvm-svn: 338420
2018-07-31 19:26:34 +00:00
Artem Dergachev cdd783713d [analyzer] Rename test: cxx17-mandatory-elision.cpp -> copy-elision.cpp
It reflects its contents more accurately. No functional change intended.

llvm-svn: 338339
2018-07-31 00:18:35 +00:00
Artem Dergachev 67fdf81f0c [analyzer] CStringChecker: Remember to highlight the argument expression range.
When emitting a bug report, it is important to highlight which argument of the
call-expression is causing the problem.

Before:
warning: Null pointer argument in call to string comparison function
  strcmp(a, b);
  ^~~~~~~~~~~~

After:
warning: Null pointer argument in call to string comparison function
  strcmp(a, b);
  ^      ~

Affects other output modes as well, not just text.

Differential Revision: https://reviews.llvm.org/D50028

llvm-svn: 338333
2018-07-30 23:44:37 +00:00
George Karpenkov 81c84a9755 [analyzer] Bugfix for autorelease + main run loop leak checker
Do not warn when the other message-send-expression is correctly wrapped
in a different autorelease pool.

Differential Revision: https://reviews.llvm.org/D49921

llvm-svn: 338314
2018-07-30 22:18:21 +00:00
George Karpenkov f44b9070b9 [analyzer] Fix crash in RunLoopAutoreleaseChecker on empty children
Differential Revision: https://reviews.llvm.org/D50012

llvm-svn: 338312
2018-07-30 21:44:15 +00:00
Reka Kovacs c74cfc4215 [analyzer] Add support for more invalidating functions in InnerPointerChecker.
According to the standard, pointers referring to the elements of a
`basic_string` may be invalidated if they are used as an argument to
any standard library function taking a reference to non-const
`basic_string` as an argument. This patch makes InnerPointerChecker warn
for these cases.

Differential Revision: https://reviews.llvm.org/D49656

llvm-svn: 338259
2018-07-30 15:43:45 +00:00
George Karpenkov b293c6bb54 [analyzer] Extend NoStoreFuncVisitor to insert a note on IVars
The note is added in the following situation:

 - We are throwing a nullability-related warning on an IVar
 - The path goes through a method which *could have* (syntactically
   determined) written into that IVar, but did not

rdar://42444460

Differential Revision: https://reviews.llvm.org/D49689

llvm-svn: 338149
2018-07-27 18:26:40 +00:00
Richard Smith 7ed5fb2d22 Add missing temporary materialization conversion on left-hand side of .
in some member function calls.

Specifically, when calling a conversion function, we would fail to
create the AST node representing materialization of the class object.

llvm-svn: 338135
2018-07-27 17:13:18 +00:00
George Karpenkov 7112483272 [analyzer] Syntactic matcher for leaks associated with run loop and autoreleasepool
A checker for detecting leaks resulting from allocating temporary
autoreleasing objects before starting the main run loop.

Checks for two antipatterns:

1. ObjCMessageExpr followed by [[NARunLoop mainRunLoop] run] in the same
autorelease pool.

2. ObjCMessageExpr followed by [[NARunLoop mainRunLoop] run] in no
autorelease pool.

Happens-before relationship is modeled purely syntactically.

rdar://39299145

Differential Revision: https://reviews.llvm.org/D49528

llvm-svn: 337876
2018-07-25 01:27:15 +00:00
George Karpenkov 5c0a822177 Revert "[analyzer] Extend NoStoreFuncVisitor to insert a note on IVars"
This reverts commit a9e21bd727112cd69eabc1af648c5da6b773d06e.
Reverted because the dependency has not landed yet.

llvm-svn: 337866
2018-07-24 23:23:33 +00:00
George Karpenkov 71692e7f00 [analyzer] Extend NoStoreFuncVisitor to insert a note on IVars
The note is added in the following situation:

 - We are throwing a nullability-related warning on an IVar
 - The path goes through a method which *could have* (syntactically
 determined) written into that IVar, but did not

rdar://42444460

Differential Revision: https://reviews.llvm.org/D49689

llvm-svn: 337864
2018-07-24 23:14:29 +00:00
Artem Dergachev 4369add18d [analyzer] Add a no-crash to a recently added test.
No functional change intended.

llvm-svn: 337776
2018-07-23 23:48:13 +00:00
Artem Dergachev 917111f91e [analyzer] pr38273: Legalize Loc<>NonLoc comparison symbols.
Remove an assertion in RangeConstraintManager that expects such symbols to never
appear, while admitting that the constraint manager doesn't yet handle them.

Differential Revision: https://reviews.llvm.org/D49703

llvm-svn: 337769
2018-07-23 23:09:44 +00:00
Richard Smith afe48f9d68 Fold -Wreturn-stack-address into general initialization lifetime
checking.

llvm-svn: 337743
2018-07-23 21:21:22 +00:00
Richard Smith ca975b2f58 Fold dangling-field warning into general initialization lifetime checks.
This reinstates r337627, reverted in r337671, with a fix to correctly
handle the lvalueness of array subscript expressions on pointers.

llvm-svn: 337726
2018-07-23 18:50:26 +00:00
David Carlier 2ea81639bd [CStringSyntaxChecker] Improvements of strlcpy check
Adding an additional check whenwe offset fro the buffer base address.

Reviewers: george.karpenkov,NoQ

Reviewed By: george.karpenkov

Differential Revision: https://reviews.llvm.org/D49633

llvm-svn: 337721
2018-07-23 18:26:38 +00:00
Adam Balogh c02139eb21 Fix for last commit: adding new test file forgotten.
llvm-svn: 337679
2018-07-23 10:53:02 +00:00
Adam Balogh dcde8acc32 [Analyzer] Quick Fix for exponential execution time when simpilifying complex additive expressions
Patch https://reviews.llvm.org/rC329780 not only rearranges comparisons but
also binary expressions. This latter behavior is not protected by the analyzer
option. Hower, since no complexity threshold is enforced to the symbols this
may result in exponential execution time if the expressions are too complex:
https://bugs.llvm.org/show_bug.cgi?id=38208. For a quick fix we extended the
analyzer option to also cover the additive cases.

This is only a temporary fix, the final solution should be enforcing the
complexity threshold to the symbols.

Differential Revision: https://reviews.llvm.org/D49536

llvm-svn: 337678
2018-07-23 10:50:20 +00:00
Ilya Biryukov e7cd2c38e8 Revert "Fold dangling-field warning into general initialization lifetime checks."
This reverts commit r337627.
After the change, clang started producing invalid warning on the following code:
    struct foo {
      foo(char *x) : x_(&x[10]) {}
    private:
      char *x_;
    };

1.cpp:2:21: warning: initializing pointer member 'x_' with the stack address of parameter 'x' [-Wdangling-field]

llvm-svn: 337671
2018-07-23 06:32:36 +00:00
Richard Smith 8aacc2cce6 Fold dangling-field warning into general initialization lifetime checks.
llvm-svn: 337627
2018-07-20 22:25:55 +00:00
David Carlier c30cedfcc0 [CStringSyntaxChecker] Fix build bot builds != x86 archs
Reviewers: NoQ,george.karpenkov

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D49588

llvm-svn: 337611
2018-07-20 20:39:49 +00:00
Reka Kovacs 88ad704b5b [analyzer] Rename DanglingInternalBufferChecker to InnerPointerChecker.
Differential Revision: https://reviews.llvm.org/D49553

llvm-svn: 337559
2018-07-20 15:14:49 +00:00
David Carlier 8e75de2100 [CStringSyntaxChecker] Check strlcpy sizeof syntax
The last argument is expected to be the destination buffer size (or less).

    Detects if it points to destination buffer size directly or via a variable.
    Detects if it is an integral, try to detect if the destination buffer can receive the source length.

Updating bsd-string.c unit tests as it make it fails now.

Reviewers: george.karpenpov, NoQ

Reviewed By: george.karpenkov

Differential Revision: https://reviews.llvm.org/D48884

llvm-svn: 337499
2018-07-19 21:50:03 +00:00
Reka Kovacs c18ecc8489 [analyzer] Add support for more basic_string API in
DanglingInternalBufferChecker.

A pointer referring to the elements of a basic_string may be invalidated
by calling a non-const member function, except operator[], at, front,
back, begin, rbegin, end, and rend. The checker now warns if the pointer
is used after such operations.

Differential Revision: https://reviews.llvm.org/D49360

llvm-svn: 337463
2018-07-19 15:10:06 +00:00
Richard Smith d87aab939a Restructure checking for, and warning on, lifetime extension.
This change implements C++ DR1696, which makes initialization of a
reference member of a class from a temporary object ill-formed. The
standard wording here is imprecise, but we interpret it as meaning that
any time a mem-initializer would result in lifetime extension, the
program is ill-formed.

This reinstates r337226, reverted in r337255, with a fix for the
InitializedEntity alignment problem that was breaking ARM buildbots.

llvm-svn: 337329
2018-07-17 22:24:09 +00:00
Florian Hahn 0aa117dd2c Temporarily revert r337226 "Restructure checking for, and warning on, lifetime extension."
This change breaks on ARM because pointers to clang::InitializedEntity are only
4 byte aligned and do not have 3 bits to store values. A possible solution
would be to change the fields in clang::InitializedEntity to enforce a bigger
alignment requirement.

The error message is

llvm/include/llvm/ADT/PointerIntPair.h:132:3: error: static_assert failed "PointerIntPair with integer size too large for pointer"
  static_assert(IntBits <= PtrTraits::NumLowBitsAvailable,
include/llvm/ADT/PointerIntPair.h:73:13: note: in instantiation of template class 'llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> >' requested here
    Value = Info::updateInt(Info::updatePointer(0, PtrVal),
llvm/include/llvm/ADT/PointerIntPair.h:51:5: note: in instantiation of member function 'llvm::PointerIntPair<const clang::InitializedEntity *, 3, (anonymous namespace)::LifetimeKind, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *>, llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> > >::setPointerAndInt' requested here
    setPointerAndInt(PtrVal, IntVal);
    ^
llvm/tools/clang/lib/Sema/SemaInit.cpp:6237:12: note: in instantiation of member function 'llvm::PointerIntPair<const clang::InitializedEntity *, 3, (anonymous namespace)::LifetimeKind, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *>, llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> > >::PointerIntPair' requested here
    return {Entity, LK_Extended};

Full log here:
http://lab.llvm.org:8011/builders/clang-cmake-armv7-global-isel/builds/1330
http://lab.llvm.org:8011/builders/clang-cmake-armv7-full/builds/1394

llvm-svn: 337255
2018-07-17 09:23:31 +00:00
Artem Dergachev fec4c1a101 [analyzer] Fix size_t in tests.
Should fix a buildbot. No functional change intended.

llvm-svn: 337231
2018-07-17 01:39:25 +00:00
Artem Dergachev 8ac6c9dd67 [CFG] [analyzer] Allow elidable copies to have more than one arguments.
Copy-constructors and move-constructors may have default arguments. It is
incorrect to assert that they only have one argument, i.e. the reference to the
object being copied or moved. Remove the assertion.

Differential Revision: https://reviews.llvm.org/D49215

llvm-svn: 337229
2018-07-17 00:57:57 +00:00
Artem Dergachev 35dbd0b1ff [analyzer] pr37802: Fix symbolic-pointer-to-boolean casts during load.
The canonical representation of pointer &SymRegion{$x} casted to boolean is
"$x != 0", not "$x". Assertion added in r337227 catches that.

Differential Revision: https://reviews.llvm.org/D48232

llvm-svn: 337228
2018-07-17 00:42:35 +00:00
Richard Smith 0a9969b36b Restructure checking for, and warning on, lifetime extension.
This change implements C++ DR1696, which makes initialization of a
reference member of a class from a temporary object ill-formed. The
standard wording here is imprecise, but we interpret it as meaning that
any time a mem-initializer would result in lifetime extension, the
program is ill-formed.

llvm-svn: 337226
2018-07-17 00:11:41 +00:00
George Karpenkov bccd6ec351 [analyzer] Bugfix for an overly eager suppression for null pointer return from macros.
Only suppress those cases where the null which came from the macro is
relevant to the bug, and was not overwritten in between.

rdar://41497323

Differential Revision: https://reviews.llvm.org/D48856

llvm-svn: 337213
2018-07-16 20:33:25 +00:00
George Karpenkov 09885d05ce [analyzer] Fix GCDAntipatternChecker to only fire when the semaphore is initialized to zero
Initializing a semaphore with a different constant most likely signals a different intent

rdar://41802552

Differential Revision: https://reviews.llvm.org/D48911

llvm-svn: 337212
2018-07-16 20:32:57 +00:00
Mikhail R. Gadelha e254b0f8c7 [analyzer] Fix constraint being dropped when analyzing a program without taint tracking enabled
Summary:
This patch removes the constraint dropping when taint tracking is disabled.

It also voids the crash reported in D28953 by treating a SymSymExpr with non pointer symbols as an opaque expression.

Updated the regressions and verifying the big projects now; I'll update here when they're done.

Based on the discussion on the mailing list and the patches by @ddcc.

Reviewers: george.karpenkov, NoQ, ddcc, baloghadamsoftware

Reviewed By: george.karpenkov

Subscribers: delcypher, llvm-commits, rnkovacs, xazax.hun, szepet, a.sidorin, ddcc

Differential Revision: https://reviews.llvm.org/D48650

llvm-svn: 337167
2018-07-16 13:14:46 +00:00
Adam Balogh bf966f5237 [Analyzer] alpha.unix.cstring.OutOfBounds checker enable/disable fix
It was not possible to disable alpha.unix.cstring.OutOfBounds checker's reports
since unix.Malloc checker always implicitly enabled the filter. Moreover if the
checker was disabled from command line (-analyzer-disable-checker ..) the out
of bounds warnings were nevertheless emitted under different checker names such
as unix.cstring.NullArg, or unix.Malloc.

This patch fixes the case sot that Malloc checker only enables implicitly the
underlying modeling of strcpy, memcpy etc. but not the warning messages that
would have been emmitted by alpha.unix.cstring.OutOfBounds

Patch by: Dániel Krupp

Differential Revision: https://reviews.llvm.org/D48831

llvm-svn: 337000
2018-07-13 13:44:44 +00:00
Kristof Umann 8c11909826 [analyzer][UninitializedObjectChecker] Fixed captured lambda variable name
Differential Revision: https://reviews.llvm.org/D48291

llvm-svn: 336995
2018-07-13 12:54:47 +00:00
Kristof Umann 7212cc0e48 [analyzer][UninitializedObjectChecker] Support for MemberPointerTypes
Differential Revision: https://reviews.llvm.org/D48325

llvm-svn: 336994
2018-07-13 12:21:38 +00:00