Commit Graph

3301 Commits

Author SHA1 Message Date
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 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
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 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
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
Fangrui Song 99337e246c Change \t to spaces
llvm-svn: 337530
2018-07-20 08:19:20 +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 a14a2fed38 [analyzer] Fix memory sanitizer error in MallocChecker.
StringRef's data() returns a string that may be non-null-terminated.
Switch to using StringRefs from const char pointers in visitor notes
to avoid problems.

llvm-svn: 337474
2018-07-19 17:43:09 +00:00
Mikhail R. Gadelha ddd4229cc4 [analyzer] Memoize complexity of SymExpr
Summary:
This patch introduces a new member to SymExpr, which stores the symbol complexity, avoiding recalculating it every time computeComplexity() is called.

Also, increase the complexity of conjured Symbols by one, so it's clear that it has a greater complexity than its underlying symbols.

Reviewers: NoQ, george.karpenkov

Reviewed By: NoQ, george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49232

llvm-svn: 337472
2018-07-19 17:03:12 +00:00
Reka Kovacs 52dd98bd1e [analyzer] Fix disappearing notes in DanglingInternalBufferChecker tests
Correct a mistake of the exact same kind I am writing this checker for.

llvm-svn: 337466
2018-07-19 15:44:46 +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
Artem Dergachev 3a37cb54e0 [analyzer] Remove a debug print that was accidentally left around.
No functional change intended.

llvm-svn: 337417
2018-07-18 18:44:40 +00:00
Mikhail R. Gadelha 81943b805b [analyzer] Fix Z3 backend after D48205
Summary:
An assertion was added in D48205 to catch places where a `nonloc::SymbolVal` was wrapping a `loc` object.

This patch fixes that in the Z3 backend by making the `SValBuilder` object accessible from inherited instances of `SimpleConstraintManager` and calling `SVB.makeSymbolVal(foo)` instead of `nonloc::SymbolVal(foo)`.

Reviewers: NoQ, george.karpenkov

Reviewed By: NoQ

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49430

llvm-svn: 337304
2018-07-17 17:40:34 +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
Artem Dergachev d1163790c3 [analyzer] Assert that nonloc::SymbolVal always wraps a non-Loc-type symbol.
In the current SVal hierarchy there are multiple ways of representing certain
values but few are actually used and expected to be seen by the code.

In particular, a value of a symbolic pointer is always represented by a
loc::MemRegionVal that wraps a SymbolicRegion that wraps the pointer symbol
and never by a nonloc::SymbolVal that wraps that symbol directly.

Assert the aforementioned fact. Fix one minor violation of it.

Differential Revision: https://reviews.llvm.org/D48205

llvm-svn: 337227
2018-07-17 00:22:27 +00:00
Reka Kovacs ed8c05cc99 [analyzer] Make checkEndFunction() give access to the return statement.
Differential Revision: https://reviews.llvm.org/D49387

llvm-svn: 337215
2018-07-16 20:47:45 +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 07f6e8e3a5 [analyzer] Fix the Z3 backend always generating unsigned APSInt
Summary:
In `toAPSInt`, the Z3 backend was not checking the variable `Int`'s type and was always generating unsigned `APSInt`s.

This was found by accident when I removed:
```
    llvm::APSInt ConvertedLHS, ConvertedRHS;
    QualType LTy, RTy;
    std::tie(ConvertedLHS, LTy) = fixAPSInt(*LHS);
    std::tie(ConvertedRHS, RTy) = fixAPSInt(*RHS);
-    doIntTypePromotion<llvm::APSInt, Z3ConstraintManager::castAPSInt>(
-        ConvertedLHS, LTy, ConvertedRHS, RTy);
    return BVF.evalAPSInt(BSE->getOpcode(), ConvertedLHS, ConvertedRHS);
```

And the `BasicValueFactory` started to complain about different `signedness`.

Reviewers: george.karpenkov, NoQ, ddcc

Reviewed By: ddcc

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49305

llvm-svn: 337169
2018-07-16 13:32:22 +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 0a7592b5e2 [Analyzer] Mark `SymbolData` parts of iterator position as live in program state maps
Marking a symbolic expression as live is non-recursive. In our checkers we
either use conjured symbols or conjured symbols plus/minus integers to
represent abstract position of iterators, so in this latter case we also
must mark the `SymbolData` part of these symbolic expressions as live to
prevent them from getting reaped.

Differential Revision: https://reviews.llvm.org/D48764

llvm-svn: 337151
2018-07-16 09:27:27 +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
Kristof Umann cc85244528 [analyzer][UninitializedObjectChecker] Moved non-member functions out of the anonymous namespace
As the code for the checker grew, it became increasinly difficult to see 
whether a function was global or statically defined. In this patch,
anything that isn't a type declaration or definition was moved out of the
anonymous namespace and is marked as static.

llvm-svn: 336901
2018-07-12 13:13:46 +00:00
Reka Kovacs 5f70d9b958 [analyzer] Track multiple raw pointer symbols in DanglingInternalBufferChecker.
Previously, the checker only tracked one raw pointer symbol for each
container object. But member functions returning a pointer to the
object's inner buffer may be called on the object several times. These
pointer symbols are now collected in a set inside the program state map
and thus all of them is checked for use-after-free problems.

Differential Revision: https://reviews.llvm.org/D49057

llvm-svn: 336835
2018-07-11 19:08:02 +00:00
George Karpenkov 0052744cc7 [analyzer] Partial revert of https://reviews.llvm.org/D49050
llvm-svn: 336755
2018-07-11 01:58:08 +00:00
George Karpenkov 95720c16b3 [analyzer] Pass through all arguments from the registerChecker() to the checker constructor
A lot of checkers could be cleaned up in a similar way

Differential Revision: https://reviews.llvm.org/D49050

llvm-svn: 336753
2018-07-11 01:23:27 +00:00
Richard Smith a3405ffcec DR330: look through array types when forming the cv-decomposition of a type.
This allows more qualification conversions, eg. conversion from
   'int *(*)[]' -> 'const int *const (*)[]'
is now permitted, along with all the consequences of that: more types
are similar, more cases are permitted by const_cast, and conversely,
fewer "casting away constness" cases are permitted by reinterpret_cast.

llvm-svn: 336745
2018-07-11 00:19:19 +00:00
Mikhail R. Gadelha 237d42bfa5 [analyzer] Add option to set maximum symbol complexity threshold
Summary:
This adds an option, max-symbol-complexity, so an user can set the maximum symbol complexity threshold.

Note that the current behaviour is equivalent to max complexity = 0, when taint analysis is not enabled and tests show that in a number of tests, having complexity = 25 yields the same results as complexity = 10000.

This patch was extracted and modified from Dominic Chen's patch, D35450.

Reviewers: george.karpenkov, NoQ, ddcc

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D49093

llvm-svn: 336671
2018-07-10 13:46:05 +00:00
Reka Kovacs bd516a61b4 [analyzer] Add support for data() in DanglingInternalBufferChecker.
DanglingInternalBufferChecker now tracks use-after-free problems related
to the incorrect usage of std::basic_string::data().

Differential Revision: https://reviews.llvm.org/D48532

llvm-svn: 336497
2018-07-07 20:29:24 +00:00
Reka Kovacs e453e60d08 [analyzer] Highlight c_str() call in DanglingInternalBufferChecker.
Add a bug visitor to DanglingInternalBufferChecker that places a note
at the point where the dangling pointer was obtained. The visitor is
handed over to MallocChecker and attached to the report there.

Differential Revision: https://reviews.llvm.org/D48522

llvm-svn: 336495
2018-07-07 19:27:18 +00:00
Reka Kovacs e0dae15d91 [analyzer] Fix -Wcovered-switch-default warning in MallocChecker.
Remove unnecessary default case that caused buildbot failures.

llvm-svn: 336493
2018-07-07 18:37:37 +00:00
Reka Kovacs 8707cd1d1b [analyzer] Highlight container object destruction in MallocChecker.
Extend MallocBugVisitor to place a note at the point where objects with
AF_InternalBuffer allocation family are destroyed.

Differential Revision: https://reviews.llvm.org/D48521

llvm-svn: 336489
2018-07-07 17:22:45 +00:00
Rafael Stahl 67676e9c99 [analyzer][ctu] fix unsortable diagnostics
Summary: In the provided test case the PathDiagnostic compare function was not able to find a difference.

Reviewers: xazax.hun, NoQ, dcoughlin, george.karpenkov

Reviewed By: george.karpenkov

Subscribers: a_sidorin, szepet, rnkovacs, a.sidorin, mikhail.ramalho, cfe-commits

Differential Revision: https://reviews.llvm.org/D48474

llvm-svn: 336275
2018-07-04 14:12:58 +00:00
Richard Smith 0a7b297d01 Factor out Clang's desired 8MB stack size constant from the various
places we hardcode it.

llvm-svn: 336231
2018-07-03 21:34:13 +00:00
Mikhail R. Gadelha 38049a51bd [analyzer] Replace the vector of ConstraintSets by a single ConstraintSet and a function to merge ConstraintSets
Now, instead of adding the constraints when they are removed, this patch adds them when they first appear and, since we walk the bug report backward, it should be the last set of ranges generated by the CSA for a given symbol.

These are the number before and after the patch:
```
Project    |  current |   patch  |
tmux       |  283.222 |  123.052 |
redis      |  614.858 |  400.347 |
openssl    |  308.292 |  307.149 |
twin       |  274.478 |  245.411 |
git        |  547.687 |  477.335 |
postgresql | 2927.495 | 2002.526 |
sqlite3    | 3264.305 | 1028.416 |
```

Major speedups in tmux and sqlite (less than half of the time), redis and postgresql were about 25% faster while the rest are basically the same.

Reviewers: NoQ, george.karpenkov

Reviewed By: george.karpenkov

Subscribers: rnkovacs, xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D48565

llvm-svn: 336002
2018-06-29 18:11:43 +00:00
Kristof Umann 9bd44390b4 [analyzer][UninitializedObjectChecker] Added a NotesAsWarnings flag
In order to better support consumers of the plist output that don't
parse note entries just yet, a 'NotesAsWarnings' flag was added.
If it's set to true, all notes will be converted to warnings.

Differential Revision: https://reviews.llvm.org/D48285

llvm-svn: 335964
2018-06-29 11:25:24 +00:00
Mikhail R. Gadelha 53ac1a2ed4 [analyzer] Fix wrong comparison generation of the ranges generated by the refutation manager
The refutation manager is removing a true bug from the test in this patch.

The problem is that the following constraint:
```
(conj_$1{struct o *}) - (reg_$3<int * r>): [-9223372036854775808, 0]
```
is encoded as:
```
(and (bvuge (bvsub $1 $3) #x8000000000000000)
     (bvule (bvsub $1 $3) #x0000000000000000))
```
The issue is that unsigned comparisons (bvuge and bvule) are being generated instead of signed comparisons (bvsge and bvsle).

When generating the expressions:
```
(conj_$1{p *}) - (reg_$3<int * r>) >= -9223372036854775808
```
and
```
(conj_$1{p *}) - (reg_$3<int * r>) <= 0
```
both -9223372036854775808 and 0 are casted to pointer type and `LTy->isSignedIntegerOrEnumerationType()` in `Z3ConstraintManager::getZ3BinExpr` only checks if the type is signed, not if it's a pointer.

Reviewers: NoQ, george.karpenkov, ddcc

Subscribers: rnkovacs, NoQ, george.karpenkov, ddcc, xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D48324

llvm-svn: 335926
2018-06-28 21:26:52 +00:00
Adam Balogh b03ed5e414 [Analyzer] Iterator Checker - Part 2: Increment, decrement operators and ahead-of-begin checks
Add handling of the begin() funcion of containers to the iterator checkers,
together with the pre- and postfix ++ and -- operators of the iterators. This
makes possible the checking of iterators dereferenced ahead of the begin of the
container.

Differential Revision: https://reviews.llvm.org/D32642

llvm-svn: 335835
2018-06-28 10:58:53 +00:00
Adam Balogh 77660ee89a [Analyzer] Constraint Manager Negates Difference
If range [m .. n] is stored for symbolic expression A - B, then we can deduce the range for B - A which is [-n .. -m]. This is only true for signed types, unless the range is [0 .. 0].

Differential Revision: https://reviews.llvm.org/D35110

llvm-svn: 335814
2018-06-28 07:35:23 +00:00
Artem Dergachev 4ba041fa25 [analyzer] Remove redundant ';'.
Fixes a compiler warning. No functionan change intended.

llvm-svn: 335808
2018-06-28 02:33:16 +00:00
Artem Dergachev 0bb974e3ee [analyzer] Use sufficiently large types for index bounds calculation.
The ProgramState::assumeInBound() API is used by checkers to make an assumption
that a certain array index is within the array's bounds (i.e. is greater than or
equal to 0 and is less than the length of the array). When the type of the
index was unspecified by the caller, it assumed that the type is 'int', which
caused some indices and sizes to truncate during calculations.

Use ArrayIndexTy by default instead, which is used by the analyzer to represent
index types and is currently hardcoded to long long.

Patch by Bevin Hansson!

Differential Revision: https://reviews.llvm.org/D46944

llvm-svn: 335803
2018-06-28 00:42:11 +00:00
Artem Dergachev 9a209ad1d8 [analyzer] Add support for pre-C++17 copy elision.
r335795 adds copy elision information to CFG. This commit allows static analyzer
to elide elidable copy constructors by constructing the objects that were
previously subject to elidable copy directly in the target region of the copy.

The chain of elided constructors may potentially be indefinitely long. This
only happens when the object is being returned from a function which in turn is
returned from another function, etc.

NRVO is not supported yet.

Differential Revision: https://reviews.llvm.org/D47671

llvm-svn: 335800
2018-06-28 00:30:18 +00:00
Artem Dergachev d18639bd13 [CFG] [analyzer] Simplify lifetime-extended temporary construction contexts.
When a temporary object is materialized and through that obtain lifetime that
is longer than the duration of the full-expression, it does not require a
temporary object destructor; it will be destroyed in a different manner.

Therefore it's not necessary to include CXXBindTemporaryExpr into the
construction context for such temporary in the CFG only to make clients
throw it away.

Differential Revision: https://reviews.llvm.org/D47667

llvm-svn: 335798
2018-06-28 00:18:52 +00:00
Artem Dergachev 4fb586c349 [analyzer] Re-enable lifetime extension for temporaries without destructors.
When an object's class provides no destructor, it's less important to
materialize that object properly because we don't have to model the destructor
correctly, so previously we skipped the support for these syntax patterns.

Additionally, fix support for construction contexts of "static temporaries"
(temporaries that are lifetime-extended by static references) because
it turned out that we only had tests for them without destructors, which caused
us to regress when we re-introduced the construction context for such
temporaries.

Differential Revision: https://reviews.llvm.org/D47658

llvm-svn: 335796
2018-06-28 00:11:42 +00:00
Artem Dergachev ff267df0de [CFG] [analyzer] Add construction contexts that explain pre-C++17 copy elision.
Before C++17 copy elision was optional, even if the elidable copy/move
constructor had arbitrary side effects. The elidable constructor is present
in the AST, but marked as elidable.

In these cases CFG now contains additional information that allows its clients
to figure out if a temporary object is only being constructed so that to pass
it to an elidable constructor. If so, it includes a reference to the elidable
constructor's construction context, so that the client could elide the
elidable constructor and construct the object directly at its final destination.

Differential Revision: https://reviews.llvm.org/D47616

llvm-svn: 335795
2018-06-28 00:04:54 +00:00
Mikhail R. Gadelha c607a9f6b8 Revert "[Analyzer] Moved RangeConstraintManager to header. NFC."
This broke a number of bots.

This reverts commit 5e1a89912d37a21c3b49ccf30600d7f498dffa9c.

llvm-svn: 335752
2018-06-27 16:45:58 +00:00
Alexander Kornienko d00ed8e2c2 [analyzer] Allow registering custom statically-linked analyzer checkers
Summary:
Add an extension point to allow registration of statically-linked Clang Static
Analyzer checkers that are not a part of the Clang tree. This extension point
employs the mechanism used when checkers are registered from dynamically loaded
plugins.

Reviewers: george.karpenkov, NoQ, xazax.hun, dcoughlin

Reviewed By: george.karpenkov

Subscribers: mgorny, mikhail.ramalho, rnkovacs, xazax.hun, szepet, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D45718

llvm-svn: 335740
2018-06-27 14:56:12 +00:00
Mikhail R. Gadelha 996965d67a [Analyzer] Moved RangeConstraintManager to header. NFC.
Summary: While at it, added a dump method to RangeSet.

Reviewers: george.karpenkov, NoQ

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D48561

llvm-svn: 335726
2018-06-27 12:42:48 +00:00
George Karpenkov dd18b11b8e [analyzer] [NFC] A convenient getter for getting a current stack frame
Differential Revision: https://reviews.llvm.org/D44756

llvm-svn: 335701
2018-06-27 01:51:55 +00:00
George Karpenkov 32919a5861 [analyzer] Minor cleanups for BugReporter, expose a getter for AnalyzerOptions.
llvm-svn: 335683
2018-06-26 23:10:05 +00:00
George Karpenkov 70ec1dd14d [analyzer] Do not run visitors until the fixpoint, run only once.
In the current implementation, we run visitors until the fixed point is
reached.
That is, if a visitor adds another visitor, the currently processed path
is destroyed, all diagnostics is discarded, and it is regenerated again,
until it's no longer modified.
This pattern has a few negative implications:

 - This loop does not even guarantee to terminate.
   E.g. just imagine two visitors bouncing a diagnostics around.
 - Performance-wise, e.g. for sqlite3 all visitors are being re-run at
   least 10 times for some bugs.
   We have already seen a few reports where it leads to timeouts.
 - If we want to add more computationally intense visitors, this will
   become worse.
 - From architectural standpoint, the current layout requires copying
   visitors, which is conceptually wrong, and can be annoying (e.g. no
   unique_ptr on visitors allowed).

The proposed change is a much simpler architecture: the outer loop
processes nodes upwards, and whenever the visitor is added it only
processes current nodes and above, thus guaranteeing termination.

Differential Revision: https://reviews.llvm.org/D47856

llvm-svn: 335666
2018-06-26 21:12:08 +00:00
Artem Dergachev 57790c5685 [analyzer] Track null and undef values through expressions with cleanups.
ExprWithCleanups wraps full-expressions that require temporary destructors
and highlights the moment of time in which these destructors need to be called
(i.e., "at the end of the full-expression...").

Such expressions don't necessarily return an object; they may return anything,
including a null or undefined value.

When the analyzer tries to understand where the null or undefined value came
from in order to present better diagnostics to the user, it will now skip
any ExprWithCleanups it encounters and look into the expression itself.

Differential Revision: https://reviews.llvm.org/D48204

llvm-svn: 335559
2018-06-25 23:55:07 +00:00
Artem Dergachev f74ef4b1e6 [analyzer] Fix invalidation on C++ const methods with arrow syntax.
Conservative evaluation of a C++ method call would invalidate the object,
as long as the method is not const or the object has mutable fields.

When checking for mutable fields, we need to scan the type of the object on
which the method is called, which may be more specific than the type of the
object on which the method is defined, hence we look up the type from the
this-argument expression.

If arrow syntax or implicit-this syntax is used, this-argument expression
has pointer type, not record type, and lookup accidentally failed for that
reason. Obtain object type correctly.

Differential Revision: https://reviews.llvm.org/D48460

llvm-svn: 335555
2018-06-25 23:43:45 +00:00
Steven Wu b3684db431 Add const qualifier on FieldChainInfoComparator::operator()
libcxx has user defined warning to check for non const call operator.
Silence the warning by adding the const on operator().

llvm-svn: 335366
2018-06-22 16:51:17 +00:00
Leonard Chan db01c3adc6 [Fixed Point Arithmetic] Fixed Point Precision Bits and Fixed Point Literals
This diff includes the logic for setting the precision bits for each primary fixed point type in the target info and logic for initializing a fixed point literal.

Fixed point literals are declared using the suffixes

```
hr: short _Fract
uhr: unsigned short _Fract
r: _Fract
ur: unsigned _Fract
lr: long _Fract
ulr: unsigned long _Fract
hk: short _Accum
uhk: unsigned short _Accum
k: _Accum
uk: unsigned _Accum
```
Errors are also thrown for illegal literal values

```
unsigned short _Accum u_short_accum = 256.0uhk;   // expected-error{{the integral part of this literal is too large for this unsigned _Accum type}}
```

Differential Revision: https://reviews.llvm.org/D46915

llvm-svn: 335148
2018-06-20 17:19:40 +00:00
Mikhail R. Gadelha bd1077e2bc [analyzer] Optimize constraint generation when the range is a concrete value
Summary:
If a constraint is something like:
```
$0 = [1,1]
```
it'll now be created as:
```
assert($0 == 1)
```
instead of:
```
assert($0 >= 1 && $0 <= 1)
```

In general, ~3% speedup when solving per query in my machine. Biggest improvement was when verifying sqlite3, total time went down from 3000s to 2200s.

I couldn't create a test for this as there is no way to dump the formula yet. D48221 adds a method to dump the formula but there is no way to do it from the command line.

Also, a test that prints the formula will most likely fail in the future, as different solvers print the formula in different formats.

Reviewers: NoQ, george.karpenkov, ddcc

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D48227

llvm-svn: 335116
2018-06-20 11:42:12 +00:00
Kristof Umann 20e85ba854 [analyzer] Made a buildbot happy.
Since `isPrimitiveType` was only used in an assert, a builbot with `-Werror`
and no asserts enabled failed to build it as it was unused.

llvm-svn: 335030
2018-06-19 08:35:02 +00:00
George Karpenkov fdbc1bf62e [analyzer] Remove accidentally committed lines.
llvm-svn: 334965
2018-06-18 17:59:03 +00:00
Kristof Umann 30f086565c [analyzer] Checker for uninitialized C++ objects
This checker analyzes C++ constructor calls, and reports uninitialized fields.

Due to the nature of this problem (uninitialized fields after an object
construction), this checker doesn't search for bugs, but rather is a tool to
enforce a specific programming model where every field needs to be initialized.

This checker lands in alpha for now, and a number of followup patches will be
made to reduce false negatives and to make it easier for the user to understand
what rules the checker relies on, eg. whether a derived class' constructor is
responsible for initializing inherited data members or whether it should be
handled in the base class' constructor.

Differential Revision: https://reviews.llvm.org/D45532

llvm-svn: 334935
2018-06-18 11:50:17 +00:00
Mikhail R. Gadelha e7f703804d [analyzer] Add method to the generic SMT API to dump the SMT formula
Summary:
New method dump the SMT formula and the Z3 implementation.

There is no test because I only used it for debugging.

However, if requested, I can add an option to the static analyzer to dump the formula (whole program? per path?), maybe something like the trimmed graph but for SMT formulas.

Reviewers: NoQ, george.karpenkov, ddcc

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin

Differential Revision: https://reviews.llvm.org/D48221

llvm-svn: 334891
2018-06-16 14:36:17 +00:00
Artem Dergachev f28d7f1721 [analyzer] Re-enable C++17-specific RVO construction contexts.
Not contexts themselves, but rather support for them in the analyzer.

Such construction contexts appear when C++17 mandatory copy elision occurs
while returning an object from a function, and presence of a destructor causes
a CXXBindTemporaryExpr to appear in the AST.

Additionally, such construction contexts may be chained, because a return-value
construction context doesn't really explain where the object is being returned
into, but only points to the parent stack frame, where the object may be
consumed by literally anything including another return statement. This
behavior is now modeled correctly by the analyzer as long as the object is not
returned beyond the boundaries of the analysis.

Differential Revision: https://reviews.llvm.org/D47405

llvm-svn: 334684
2018-06-14 01:59:35 +00:00
Artem Dergachev 53b8ce0edb [analyzer] Re-enable C++17-specific variable and member construction contexts.
Not contexts themselves, but rather support for them in the analyzer.

Such construction contexts appear when C++17 mandatory copy elision occurs
during initialization, and presence of a destructor causes a
CXXBindTemporaryExpr to appear in the AST.

Similar C++17-specific constructors for return values are still to be supported.

Differential Revision: https://reviews.llvm.org/D47351

llvm-svn: 334683
2018-06-14 01:54:21 +00:00
Artem Dergachev a84374dc0e [analyzer] Track class member initializer constructors path-sensitively.
The reasoning behind this change is similar to the previous commit, r334681.
Because members are already in scope when construction occurs, we are not
suffering from liveness problems, but we still want to figure out if the object
was constructed with construction context, because in this case we'll be able
to avoid trivial copy, which we don't always model perfectly. It'd also have
more importance when copy elision is implemented.

This also gets rid of the old CFG look-behind mechanism.

Differential Revision: https://reviews.llvm.org/D47350

llvm-svn: 334682
2018-06-14 01:40:49 +00:00
Artem Dergachev 1fe52474d2 [analyzer] pr37270: Track constructor target region, even if just a variable.
The very idea of construction context implies that first the object is
constructed, and then later, in a separate moment of time, the constructed
object goes into scope, i.e. becomes "live".

Most construction contexts require path-sensitive tracking of the constructed
object region in order to compute the outer expressions accordingly before
the object becomes live.

Semantics of simple variable construction contexts don't immediately require
that such tracking happens in path-sensitive manner, but shortcomings of the
analyzer force us to track it path-sensitively as well. Namely, whether
construction context was available at all during construction is a
path-sensitive information. Additionally, path-sensitive tracking takes care of
our liveness problems that kick in as the temporal gap between construction and
going-into-scope becomes larger (eg., due to copy elision).

Differential Revision: https://reviews.llvm.org/D47305

llvm-svn: 334681
2018-06-14 01:32:46 +00:00
Artem Dergachev 239452ca3e [analyzer] NFC: Merge code for finding and tracking construction target.
When analyzing C++ code, a common operation in the analyzer is to discover
target region for object construction by looking at CFG metadata ("construction
contexts"), and then track the region path-sensitively until object construction
is resolved, where the amount of information, again, depends on construction
context.

Scan construction context only once for both purposes.

Differential Revision: https://reviews.llvm.org/D47304

llvm-svn: 334678
2018-06-14 01:20:12 +00:00
George Karpenkov 0cba5549ef [analyzer] Fix offset overflow check in MemRegion
rdar://39593879
https://bugs.llvm.org/show_bug.cgi?id=37142

Differential Revision: https://reviews.llvm.org/D48139

llvm-svn: 334636
2018-06-13 18:32:19 +00:00
Bill Wendling 744c48a146 Remove extraneous semicolon.
llvm-svn: 334573
2018-06-13 06:33:59 +00:00
George Karpenkov e6fdb6a28c [analyzer] Do not crash in the visitor when the function is given more arguments than it has parameters
rdar://40335545

Differential Revision: https://reviews.llvm.org/D48107

llvm-svn: 334560
2018-06-12 23:53:54 +00:00
Matthew Voss 6b9359509c [analyzer] Ensure that loop widening does not invalidate references
Loop widening can invalidate a reference. If the analyzer attempts to visit the
destructor to a non-existent reference, it will crash. This patch ensures that
the reference is preserved.

https://reviews.llvm.org/D47044

llvm-svn: 334554
2018-06-12 22:22:35 +00:00
George Karpenkov cd45bef232 [analyzer] [NFC] Remove "removeInvalidation" from visitor API
removeInvalidation is a very problematic API, as it makes suppression
order-dependent.
Moreover, it was used only once, and could be rewritten in a much
cleaner way.

Differential Revision: https://reviews.llvm.org/D48045

llvm-svn: 334542
2018-06-12 20:51:19 +00:00
George Karpenkov 1cf8cdc687 [analyzer] [NFC] Move ::dump methods from BugReporter.cpp to PathDiagnostics.cpp
BugReporter.cpp is already severely overloaded, and those dump methods
are on PathDiagnostics and should belong in the corresponding
implementation file.

Differential Revision: https://reviews.llvm.org/D48035

llvm-svn: 334541
2018-06-12 20:51:01 +00:00
George Karpenkov 5ec0a2613f [analyzer] [NFC] Remove most usages of getEndPath
getEndPath is a problematic API, because it's not clear when it's called
(hint: not always at the end of the path), it crashes at runtime with
more than one non-nullptr returning implementation, and diagnostics
internal depend on it being called at some exact place.

However, most visitors don't actually need that: all they want is a
function consistently called after all nodes are traversed, to perform
finalization and to decide whether invalidation is needed.

Differential Revision: https://reviews.llvm.org/D48042

llvm-svn: 334540
2018-06-12 20:50:44 +00:00
Fangrui Song 8b4b82eed4 Work around false -Wmissing-braces warning from old clang which has been fixed in r314838
llvm-svn: 334539
2018-06-12 20:44:11 +00:00
George Karpenkov 4872750dd3 [analyzer] [NFC] Now let's have only one place for diagnostics generation
Differential Revision: https://reviews.llvm.org/D47808

llvm-svn: 334526
2018-06-12 19:08:17 +00:00
George Karpenkov 8ade563870 [analyzer] [NFC] Unify Minimal and Extensive diagnostics.
Once we removed AlternateExtensive, I've looked closer into the
difference between Minimal and Extensive, and turns out, the difference
was not that large.

Differential Revision: https://reviews.llvm.org/D47756

llvm-svn: 334525
2018-06-12 19:08:00 +00:00
George Karpenkov 391650912a [analyzer] [NFC] Remove unused Extensive diagnostic setting,
Rename AlternateExtensive to Extensive.
In 2013, five years ago, we have switched to AlternateExtensive
diagnostics by default, and Extensive was available under unused,
undocumented flag.
This change remove the flag, renames the Alternate
diagnostic to Extensive (as it's no longer Alternate), and ports the
test.

Differential Revision: https://reviews.llvm.org/D47670

llvm-svn: 334524
2018-06-12 19:07:41 +00:00
Zachary Turner 08426e1f9f Refactor ExecuteAndWait to take StringRefs.
This simplifies some code which had StringRefs to begin with, and
makes other code more complicated which had const char* to begin
with.

In the end, I think this makes for a more idiomatic and platform
agnostic API.  Not all platforms launch process with null terminated
c-string arrays for the environment pointer and argv, but the api
was designed that way because it allowed easy pass-through for
posix-based platforms.  There's a little additional overhead now
since on posix based platforms we'll be takign StringRefs which
were constructed from null terminated strings and then copying
them to null terminate them again, but from a readability and
usability standpoint of the API user, I think this API signature
is strictly better.

llvm-svn: 334518
2018-06-12 17:43:52 +00:00
Reka Kovacs 7ff6a8a316 [analyzer] Clean up the program state map of DanglingInternalBufferChecker.
Symbols are cleaned up from the program state map when they go out of scope.
Memory regions are cleaned up when the corresponding object is destroyed, and
additionally in 'checkDeadSymbols' in case destructor modeling was incomplete.

Differential Revision: https://reviews.llvm.org/D47416

llvm-svn: 334352
2018-06-09 21:08:27 +00:00
Reka Kovacs 18775fc9b7 [analyzer] Add dangling internal buffer check.
This check will mark raw pointers to C++ standard library container internal
buffers 'released' when the objects themselves are destroyed. Such information
can be used by MallocChecker to warn about use-after-free problems.

In this first version, 'std::basic_string's are supported.

Differential Revision: https://reviews.llvm.org/D47135

llvm-svn: 334348
2018-06-09 13:03:49 +00:00
Zachary Turner 1f67a3cba9 [FileSystem] Split up the OpenFlags enumeration.
This breaks the OpenFlags enumeration into two separate
enumerations: OpenFlags and CreationDisposition.  The first
controls the behavior of the API depending on whether or not
the target file already exists, and is not a flags-based
enum.  The second controls more flags-like values.

This yields a more easy to understand API, while also allowing
flags to be passed to the openForRead api, where most of the
values didn't make sense before.  This also makes the apis more
testable as it becomes easy to enumerate all the configurations
which make sense, so I've added many new tests to exercise all
the different values.

llvm-svn: 334221
2018-06-07 19:58:58 +00:00
Vlad Tsyrklevich 6f8f15fa72 [Analyzer] Fix Z3ConstraintManager crash (PR37646)
Summary:
Fix another Z3ConstraintManager crash, use fixAPSInt() to extend a
boolean APSInt.

Reviewers: george.karpenkov, NoQ, ddcc

Reviewed By: george.karpenkov

Subscribers: xazax.hun, szepet, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D47617

llvm-svn: 334065
2018-06-06 06:09:02 +00:00
Artem Dergachev 643102dfce [analyzer] Re-enable constructors when lifetime extension through fields occurs.
Temporary object constructor inlining was disabled in r326240 for code like

    const int &x = A().x;

because automatic destructor for the lifetime-extended object A() was not
working correctly in CFG.

CFG was fixed in r333941, so inlining can be re-enabled. CFG for lifetime
extension through aggregates still needs to be fixed.

Differential Revision: https://reviews.llvm.org/D44239

llvm-svn: 333946
2018-06-04 20:18:37 +00:00
Mikhail R. Gadelha 8cd2ee1f24 [analyzer] False positive refutation with Z3
Summary: This is a prototype of a bug reporter visitor that invalidates bug reports by re-checking constraints of certain states on the bug path using the Z3 constraint manager backend. The functionality is available under the `crosscheck-with-z3` analyzer config flag.

Reviewers: george.karpenkov, NoQ, dcoughlin, rnkovacs

Reviewed By: george.karpenkov

Subscribers: rnkovacs, NoQ, george.karpenkov, dcoughlin, xbolva00, ddcc, mikhail.ramalho, MTC, fhahn, whisperity, baloghadamsoftware, szepet, a.sidorin, gsd, dkrupp, xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D45517

llvm-svn: 333903
2018-06-04 14:40:44 +00:00
Mikhail R. Gadelha 735d8ea0d4 Created a tiny SMT interface and make Z3ConstraintManager implement it
Summary:
This patch implements a simple SMTConstraintManager API, and requires the implementation of two methods for now: `addRangeConstraints` and `isModelFeasible`.

Update Z3ConstraintManager to inherit it and implement required methods.

I also moved the method to dump the SMT formula from D45517 to this patch.

This patch was created based on the reviews from D47640.

Reviewers: george.karpenkov, NoQ, ddcc, dcoughlin

Reviewed By: george.karpenkov

Differential Revision: https://reviews.llvm.org/D47689

llvm-svn: 333899
2018-06-04 14:25:58 +00:00
Mikhail R. Gadelha c10f611522 Moved RangedConstraintManager header to the StaticAnalyser include dir
Summary:
Moved `RangedConstraintManager` header from  `lib/StaticAnalyzer/Core/` to `clang/StaticAnalyzer/Core/PathSensitive/`. No changes to the code.

Reviewers: NoQ, george.karpenkov, dcoughlin

Reviewed By: george.karpenkov

Subscribers: NoQ, george.karpenkov, dcoughlin, ddcc

Differential Revision: https://reviews.llvm.org/D47640

llvm-svn: 333862
2018-06-04 00:23:01 +00:00
Artem Dergachev f83d547989 [analyzer] NFC: Track all constructed objects in a single state trait.
ExprEngine already maintains three internal program state traits to track
path-sensitive information related to object construction: pointer returned by
operator new, and pointer to temporary object for two different purposes - for
destruction and for lifetime extension. We'll need to add 2-3 more in a few
follow-up commits.

Merge these traits into one because they all essentially serve one purpose and
work similarly.

Differential Revision: https://reviews.llvm.org/D47303

llvm-svn: 333719
2018-06-01 01:59:48 +00:00
Dominic Chen cd81614e8b [analyzer] fix bug with 1-bit APSInt types in Z3ConstraintManager
Summary: Clang does not have a corresponding QualType for a 1-bit APSInt, so use the BoolTy and extend the APSInt. Split from D35450. Fixes PR37622.

Reviewers: george.karpenkov, NoQ

Subscribers: mikhail.ramalho, xazax.hun, szepet, rnkovacs, cfe-commits, a.sidorin

Differential Revision: https://reviews.llvm.org/D47603

llvm-svn: 333704
2018-05-31 22:23:07 +00:00
Artem Dergachev 22746d7df3 [analyzer] Improve performance of the SVal simplification mechanism further.
Memoize simplification so that we didn't need to simplify the same symbolic
expression twice within the same program state.

Gives ~25% performance boost on the artificial test in test/Analysis/hangs.c.

Differential Revision: https://reviews.llvm.org/D47402

llvm-svn: 333671
2018-05-31 17:27:28 +00:00
Artem Dergachev 16a1f64ccf [analyzer] Improve performance of the SVal simplification mechanism.
When neither LHS nor RHS of a binary operator expression can be simplified,
return the original expression instead of re-evaluating the binary operator.

Such re-evaluation was causing recusrive re-simplification which caused
the algorithmic complexity to explode.

Differential Revision: https://reviews.llvm.org/D47155

llvm-svn: 333670
2018-05-31 17:22:38 +00:00
George Karpenkov 7744c7f137 [analyzer] Trust _Nonnull annotations, and trust analyzer knowledge about receiver nullability
Previously, the checker was using the nullability of the expression,
which is nonnull IFF both receiver and method are annotated as _Nonnull.
However, the receiver could be known to the analyzer to be nonnull
without being explicitly marked as _Nonnull.

rdar://40635584

Differential Revision: https://reviews.llvm.org/D47510

llvm-svn: 333612
2018-05-31 00:28:13 +00:00
Henry Wong 716515a51e [analyzer] Remove the redundant check about same state transition in `ArrayBoundCheckerV2.cpp`.
Summary: Since the `addTransitionImpl()` has a check about same state transition, there is no need to check it in `ArrayBoundCheckerV2.cpp`.

Reviewers: NoQ, xazax.hun, george.karpenkov

Reviewed By: NoQ

Subscribers: szepet, rnkovacs, a.sidorin, cfe-commits, MTC

Differential Revision: https://reviews.llvm.org/D47451

llvm-svn: 333531
2018-05-30 11:46:45 +00:00
Rafael Stahl 0137aa8679 [analyzer] const init: handle non-explicit cases more accurately
Summary: If the access is out of bounds, return UndefinedVal. If it is missing an explicit init, return the implicit zero value it must have.

Reviewers: NoQ, xazax.hun, george.karpenkov

Reviewed By: NoQ

Subscribers: szepet, rnkovacs, a.sidorin, cfe-commits

Differential Revision: https://reviews.llvm.org/D46823

llvm-svn: 333417
2018-05-29 14:14:22 +00:00
Artem Dergachev 8419cf307e [analyzer] Add security checks for bcmp(), bcopy(), bzero().
These functions are obsolete. The analyzer would advice to replace them with
memcmp(), memcpy() or memmove(), or memset().

Patch by Tom Rix!

Differential Revision: https://reviews.llvm.org/D41881

llvm-svn: 333326
2018-05-26 00:04:26 +00:00
Kristof Umann 3ea7442bd6 [analyzer] Added template argument lists to the Pathdiagnostic output
Because template parameter lists were not displayed
in the plist output, it was difficult to decide in
some cases whether a given checker found a true or a
false positive. This patch aims to correct this.

Differential Revision: https://reviews.llvm.org/D46933

llvm-svn: 333275
2018-05-25 13:18:38 +00:00
Mikhail R. Gadelha 6c4c55ce9e [analyzer] Move RangeSet related declarations into the RangedConstraintManager header.
Summary: I could also move `RangedConstraintManager.h` under `include/` if you agree as it seems slightly out of place under `lib/`.

Patch by Réka Kovács

Reviewers: NoQ, george.karpenkov, dcoughlin, rnkovacs

Reviewed By: NoQ

Subscribers: mikhail.ramalho, whisperity, xazax.hun, baloghadamsoftware, szepet, a.sidorin, dkrupp, cfe-commits

Differential Revision: https://reviews.llvm.org/D45920

llvm-svn: 333179
2018-05-24 12:16:35 +00:00