Commit Graph

4247 Commits

Author SHA1 Message Date
Gabor Marton 11d2e63ab0 [analyzer][StdLibraryFunctionsChecker] Separate the signature from the summaries
The signature should not be part of the summaries as many FIXME comments
suggests. By separating the signature, we open up the way to a generic
matching implementation which could be used later under the hoods of
CallDescriptionMap.

Differential Revision: https://reviews.llvm.org/D88100
2020-09-23 10:59:34 +02:00
Gabor Marton d63a945a13 [analyzer][StdLibraryFunctionsChecker] Fix getline/getdelim signatures
It is no longer needed to add summaries of 'getline' for different
possible underlying types of ssize_t. We can just simply lookup the
type.

Differential Revision: https://reviews.llvm.org/D88092
2020-09-23 10:48:14 +02:00
Jan Korous 47e6851423 [Analyzer][WebKit] Use tri-state types for relevant predicates
Some of the predicates can't always be decided - for example when a type
definition isn't available. At the same time it's necessary to let
client code decide what to do about such cases - specifically we can't
just use true or false values as there are callees with
conflicting strategies how to handle this.

This is a speculative fix for PR47276.

Differential Revision: https://reviews.llvm.org/D88133
2020-09-22 21:57:24 -07:00
Jan Korous 8a64689e26 [Analyzer][WebKit] UncountedLocalVarsChecker
Differential Review: https://reviews.llvm.org/D83259
2020-09-22 11:05:04 -07:00
Chris Hamilton 2697d138a6 [Analyzer] GNU named variadic macros in Plister
Added support for GNU named variadic macros in
macro expansion for plist generation.

Fix for https://bugs.llvm.org/show_bug.cgi?id=44493

Reviewed By: Szelethus

Differential Revision: https://reviews.llvm.org/D87942
2020-09-21 15:38:28 -05:00
Gabor Marton 0c4f91f84b [analyzer][solver] Fix issue with symbol non-equality tracking
We should track non-equivalency (disequality) in case of greater-then or
less-then assumptions.

Differential Revision: https://reviews.llvm.org/D88019
2020-09-21 16:59:18 +02:00
Kristóf Umann dd1d5488e4 [analyzer][Liveness][NFC] Get rid of statement liveness, because such a thing doesn't exist
The summary and very short discussion in D82122 summarizes whats happening here.

In short, liveness talks about variables, or expressions, anything that
has a value. Well, statements just simply don't have a one.

Differential Revision: https://reviews.llvm.org/D82598
2020-09-15 17:43:02 +02:00
Gabor Marton a012bc4c42 [analyzer][StdLibraryFunctionsChecker] Elaborate the summary of fread and fwrite
Add the BufferSize argument constraint to fread and fwrite. This change
itself makes it possible to discover a security critical case, described
in SEI-CERT ARR38-C.

We also add the not-null constraint on the 3rd arguments.

In this patch, I also remove those lambdas that don't take any
parameters (Fwrite, Fread, Getc), thus making the code better
structured.

Differential Revision: https://reviews.llvm.org/D87081
2020-09-15 16:35:39 +02:00
Balazs Benics cdacffe4ac [analyzer][z3] Use more elaborate Z3 variable names
Previously, it was a tedious task to comprehend Z3 dumps.
We will use the same name prefix just as we use in the corresponding dump method

For all `SymbolData` values:
    `$###` -> `conj_$###`
    `$###` -> `derived_$###`
    `$###` -> `extent_$###`
    `$###` -> `meta_$###`
    `$###` -> `reg_$###`

Reviewed By: xazax.hun,mikhail.ramalho

Differential Revision: https://reviews.llvm.org/D86223
2020-09-14 08:43:56 +02:00
Balazs Benics 163863604f [analyzer] Evaluate PredefinedExpressions
We did not evaluate such expressions, just returned `Unknown` for such cases.
After this patch, we will be able to access a unique value identifying a template instantiation via the value of the `PRETTY_FUNCTION` predefined expression.

Reviewed By: vsavchenko

Differential Revision: https://reviews.llvm.org/D87004
2020-09-14 08:43:56 +02:00
Vitaly Buka a8503b87f7 [NFC] Remove unused static function 2020-09-11 16:50:30 -07:00
Kristóf Umann b9bca883c9 [analyzer][NFC] Don't bind values to ObjCForCollectionStmt, replace it with a GDM trait
Based on the discussion in D82598#2171312. Thanks @NoQ!

D82598 is titled "Get rid of statement liveness, because such a thing doesn't
exist", and indeed, expressions express a value, non-expression statements
don't.

if (a && get() || []{ return true; }())
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ has a value
    ~ has a value
    ~~~~~~~~~~ has a value
                  ~~~~~~~~~~~~~~~~~~~~ has a value
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ doesn't have a value

That is simple enough, so it would only make sense if we only assigned symbolic
values to expressions in the static analyzer. Yet the interface checkers can
access presents, among other strange things, the following two methods:

ProgramState::BindExpr(const Stmt *S, const LocationContext *LCtx, SVal V,
                       bool Invalidate=true)
ProgramState::getSVal(const Stmt *S, const LocationContext *LCtx)

So, what gives? Turns out, we make an exception for ReturnStmt (which we'll
leave for another time) and ObjCForCollectionStmt. For any other loops, in order
to know whether we should analyze another iteration, among other things, we
evaluate it's condition. Which is a problem for ObjCForCollectionStmt, because
it simply doesn't have one (CXXForRangeStmt has an implicit one!). In its
absence, we assigned the actual statement with a concrete 1 or 0 to indicate
whether there are any more iterations left. However, this is wildly incorrect,
its just simply not true that the for statement has a value of 1 or 0, we can't
calculate its liveness because that doesn't make any sense either, so this patch
turns it into a GDM trait.

Fixing this allows us to reinstate the assert removed in
https://reviews.llvm.org/rG032b78a0762bee129f33e4255ada6d374aa70c71.

Differential Revision: https://reviews.llvm.org/D86736
2020-09-11 15:58:48 +02:00
Kristóf Umann be0d79f329 [analyzer][MacroExpansion] Fix a crash where multiple parameters resolved to __VA_ARGS__
In short, macro expansions handled the case where a variadic parameter mapped to
multiple arguments, but not the other way around. An internal ticket was
submitted that demonstrated that we fail an assertion. Macro expansion so far
worked by lexing the source code token-by-token and using the Preprocessor to
turn these tokens into identifiers or just get their proper spelling, but what
this counter intuitively doesn't do, is actually expand these macros, so we have
to do the heavy lifting -- in this case, figure out what __VA_ARGS__ expands
into. Since this case can only occur in a nested macro, the information we
gathered from the containing macro does contain this information. If a parameter
resolves to __VA_ARGS__, we need to temporarily stop getting our tokens from the
lexer, and get the tokens from what __VA_ARGS__ maps to.

Differential Revision: https://reviews.llvm.org/D86135
2020-09-11 14:07:58 +02:00
Kirstóf Umann 26d9a94681 [analyzer][MacroExpansion][NFC] Fix incorrectly calling parameters arguments 2020-09-11 13:33:02 +02:00
Kirstóf Umann 1c08da3867 [analyzer][MacroExpansion] Add a few dumps functions 2020-09-11 13:29:14 +02:00
Gabor Marton a97648b938 [analyzer][StdLibraryFunctionsChecker] Add better diagnostics
Differential Revision: https://reviews.llvm.org/D79431
2020-09-10 12:43:40 +02:00
Gabor Marton b7586afc4d [analyzer][StdLibraryFunctionsChecker] Remove strcasecmp
There are 2 reasons to remove strcasecmp and strncasecmp.
1) They are also modeled in CStringChecker and the related argumentum
   contraints are checked there.
2) The argument constraints are checked in CStringChecker::evalCall.
   This is fundamentally flawed, they should be checked in checkPreCall.
   Even if we set up CStringChecker as a weak dependency for
   StdLibraryFunctionsChecker then the latter reports the warning always.
   Besides, CStringChecker fails to discover the constraint violation
   before the call, so, its evalCall returns with `true` and then
   StdCLibraryFunctions also tries to evaluate, this causes an assertion
   in CheckerManager.

Either we fix CStringChecker to handle the call prerequisites in
checkPreCall, or we must not evaluate any pure functions in
StdCLibraryFunctions that are also handled in CStringChecker.
We do the latter in this patch.

Differential Revision: https://reviews.llvm.org/D87239
2020-09-10 12:29:39 +02:00
Denys Petrov e674051418 [analyzer] [NFC] Introduce refactoring of PthreadLockChecker
Change capitalization of some names due to LLVM naming rules.
Change names of some variables to make them more speaking.
Rework similar bug reports into one common function.

Prepare code for the next patches to reduce unrelated changes.

Differential Revision: https://reviews.llvm.org/D87138
2020-09-08 16:04:19 +03:00
Gabor Marton d01280587d [analyzer][StdLibraryFunctionsChecker] Add POSIX pthread handling functions
Differential Revision: https://reviews.llvm.org/D84415
2020-09-07 17:47:01 +02:00
Eduardo Caldas 1a7a2cd747 [Ignore Expressions][NFC] Refactor to better use `IgnoreExpr.h` and nits
This change groups
* Rename: `ignoreParenBaseCasts` -> `IgnoreParenBaseCasts` for uniformity
* Rename: `IgnoreConversionOperator` -> `IgnoreConversionOperatorSingleStep` for uniformity
* Inline `IgnoreNoopCastsSingleStep` into a lambda inside `IgnoreNoopCasts`
* Refactor `IgnoreUnlessSpelledInSource` to make adequate use of `IgnoreExprNodes`

Differential Revision: https://reviews.llvm.org/D86880
2020-09-07 09:32:30 +00:00
Gabor Marton f0b9dbcfc7 [analyzer][StdLibraryFunctionsChecker] Add POSIX time handling functions
Differential Revision: https://reviews.llvm.org/D84248
2020-09-04 18:44:12 +02:00
Gabor Marton fe0972d3e4 [analyzer][StdLibraryFunctionsChecker] Do not match based on the restrict qualifier in C++
The "restrict" keyword is illegal in C++, however, many libc
implementations use the "__restrict" compiler intrinsic in functions
prototypes. The "__restrict" keyword qualifies a type as a restricted type
even in C++.
In case of any non-C99 languages, we don't want to match based on the
restrict qualifier because we cannot know if the given libc implementation
qualifies the paramter type or not.

Differential Revision: https://reviews.llvm.org/D87097
2020-09-04 11:48:38 +02:00
Gabor Marton a787a4ed16 [analyzer][StdLibraryFunctionsChecker] Use Optionals throughout the summary API
By using optionals, we no longer have to check the validity of types that we
get from a lookup. This way, the definition of the summaries have a declarative
form, there are no superflous conditions in the source code.

Differential Revision: https://reviews.llvm.org/D86531
2020-09-01 11:36:20 +02:00
Hubert Tong d563d7a731 [analyzer][NFC] Add `override` keyword missing from D86027
Speculative fix for `-Werror,-Wsuggest-override` build failures on
the ppc64le-lld-multistage-test bot.
2020-08-31 17:57:22 -04:00
Nithin Vadukkumchery Rajendrakumar bc3d4d9ed7 [analyzer] Add bool operator modeling for unque_ptr
Summary: Implemented boolean conversion operator for unique_ptr

Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

Reviewed By: NoQ, xazax.hun

Subscribers: martong, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D86027
2020-08-31 19:25:33 +02:00
Nithin Vadukkumchery Rajendrakumar 1b743a9efa [analyzer] Add modeling for unique_ptr move constructor
Summary:
Add support for handling move contructor of std::unique_ptr.

Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

Reviewed By: NoQ

Subscribers: martong, cfe-commits
Tags: #clang

Differential Revision: https://reviews.llvm.org/D86373
2020-08-31 14:36:11 +02:00
Yang Fan 6e26e49edf [analyzer] NFC: Fix wrong parameter name in printFormattedEntry.
Parameters were in a different order in the header and in the implementation.

Fix surrounding comments a bit.

Differential Revision: https://reviews.llvm.org/D86691
2020-08-27 12:15:26 -07:00
Yang Fan 37c21dbb3a [analyzer] Fix the debug print about debug egraph dumps requiring asserts.
There's no need to remind people about that when clang *is* built with asserts.

Differential Revision: https://reviews.llvm.org/D86334
2020-08-27 12:15:26 -07:00
Adam Balogh 4448affede [analyzer] pr47037: CastValueChecker: Support for the new variadic isa<>.
llvm::isa<>() and llvm::isa_and_not_null<>() template functions recently became
variadic. Unfortunately this causes crashes in case of isa_and_not_null<>()
and incorrect behavior in isa<>(). This patch fixes this issue.

Differential Revision: https://reviews.llvm.org/D85728
2020-08-27 12:15:25 -07:00
Adam Balogh 5a9e778939 [analyzer] NFC: Store the pointee/referenced type for dynamic type tracking.
The successfulness of a dynamic cast depends only on the C++ class, not the pointer or reference. Thus if *A is a *B, then &A is a &B,
const *A is a const *B etc. This patch changes DynamicCastInfo to store
and check the cast between the unqualified pointed/referenced types.
It also removes e.g. SubstTemplateTypeParmType from both the pointer
and the pointed type.

Differential Revision: https://reviews.llvm.org/D85752
2020-08-27 12:15:23 -07:00
Nithin Vadukkumchery Rajendrakumar 20676cab11 [analyzer] Add modeling of assignment operator in smart ptr
Summary: Support for 'std::unique_ptr>::operator=' in SmartPtrModeling

Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

Reviewed By: NoQ, vsavchenko, xazax.hun

Subscribers: martong, cfe-commits
Tags: #clang

Differential Revision: https://reviews.llvm.org/D86293
2020-08-26 11:22:55 +02:00
Nithin Vadukkumchery Rajendrakumar 55208f5a21 [analyzer] Add modeling for unque_ptr::get()
Summary: Implemented  modeling for get() method in SmartPtrModeling

Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

Reviewed By: NoQ, xazax.hun

Subscribers: martong, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D86029
2020-08-23 14:50:26 +02:00
Nithin Vadukkumchery Rajendrakumar b34b1e3838 [Analysis] Bug fix for exploded graph branching in evalCall for constructor
Summary:
Make exactly single NodeBuilder exists at any given time

Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

Reviewed By: NoQ

Subscribers: martong, cfe-commits
Tags: #clang

Differential Revision: https://reviews.llvm.org/D85796
2020-08-19 00:03:31 +02:00
Valeriy Savchenko 9cbfdde2ea [analyzer] Fix crash with pointer to members values
This fix unifies all of the different ways we handled pointer to
members into one.  The crash was caused by the fact that the type
of pointer-to-member values was `void *`, and while this works
for the vast majority of cases it breaks when we actually need
to explain the path for the report.

rdar://problem/64202361

Differential Revision: https://reviews.llvm.org/D85817
2020-08-13 18:03:59 +03:00
Zurab Tsinadze 25bbe234e4 [analyzer] StdLibraryFunctionsChecker: Add support for new functions
`toupper`, `tolower`, `toascii` functions were added to
StdLibraryFunctionsChecker to fully cover CERT STR37-C rule:
https://wiki.sei.cmu.edu/confluence/x/BNcxBQ

Differential Revision: https://reviews.llvm.org/D85093
2020-08-12 16:20:00 +02:00
Nithin Vadukkumchery Rajendrakumar 06d100a69a [Analyzer] Support note tags for smart ptr checker
Summary:
Added support for note tags for null smart_ptr reporting

Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

Reviewed By: NoQ, vsavchenko, xazax.hun

Subscribers: martong, cfe-commits
Tags: #clang

Differential Revision: https://reviews.llvm.org/D84600
2020-08-11 23:27:16 +02:00
Balázs Kéri 497d060d0a [Analyzer] Improve invalid dereference bug reporting in DereferenceChecker.
Report undefined pointer dereference in similar way as null pointer dereference.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D84520
2020-08-11 10:10:13 +02:00
Artem Dergachev 47cadd6106 [analyzer] pr47030: MoveChecker: Unforget a comma in the suppression list. 2020-08-07 10:39:28 -07:00
Jan Korous 820e8d8656 [Analyzer][WebKit] UncountedLambdaCaptureChecker
Differential Revision: https://reviews.llvm.org/D82837
2020-08-05 15:23:55 -08:00
Bruno Ricci 19701458d4
[clang][nearly-NFC] Remove some superfluous uses of NamedDecl::getNameAsString
`OS << ND->getDeclName();` is equivalent to `OS << ND->getNameAsString();`
without the extra temporary string.

This is not quite a NFC since two uses of `getNameAsString` in a
diagnostic are replaced, which results in the named entity being
quoted with additional "'"s (ie: 'var' instead of var).
2020-08-05 13:54:37 +01:00
Endre Fülöp 141cb8a1ee [analyzer] Model iterator random incrementation symmetrically
Summary:
In case a pointer iterator is incremented in a binary plus expression
(operator+), where the iterator is on the RHS, IteratorModeling should
now detect, and track the resulting value.

Reviewers: Szelethus, baloghadamsoftware

Reviewed By: baloghadamsoftware

Subscribers: rnkovacs, whisperity, xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, Charusso, steakhal, martong, ASDenysPetrov, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D83190
2020-08-04 11:04:12 +02:00
Denys Petrov 86e1b73507 [analyzer] Simplify function SVal::getAsSymbolicExpression and similar ones
Summary: Simplify functions SVal::getAsSymbolicExpression SVal::getAsSymExpr and SVal::getAsSymbol. After revision I concluded that `getAsSymbolicExpression` and `getAsSymExpr` repeat functionality of `getAsSymbol`, thus them can be removed.

Fix: Remove functions SVal::getAsSymbolicExpression and SVal::getAsSymExpr.

Differential Revision: https://reviews.llvm.org/D85034
2020-08-03 15:03:35 +03:00
Balázs Kéri b22b97b3d0 [Analyzer] Use of BugType in DereferenceChecker (NFC).
Use of BuiltinBug is replaced by BugType.
Class BuiltinBug seems to have no benefits and is confusing.

Reviewed By: Szelethus, martong, NoQ, vsavchenko

Differential Revision: https://reviews.llvm.org/D84494
2020-07-30 08:33:12 +02:00
Kirstóf Umann 032b78a076 [analyzer] Revert the accidental commit of D82122
Was accidentally squished into
rGb6cbe6cb0399d4671e5384dcc326af56bc6bd122. The assert fires on the code
snippet included in this commit.

More discussion can be found in https://reviews.llvm.org/D82598.
2020-07-24 21:33:18 +02:00
Balázs Kéri 65fd651980 [Analyzer][StreamChecker] Use BugType::SuppressOnSink at resource leak report.
Summary:
Use the built-in functionality BugType::SuppressOnSink
instead of a manual solution in StreamChecker.

Differential Revision: https://reviews.llvm.org/D83120
2020-07-23 11:53:25 +02:00
Valeriy Savchenko e63b488f27 [analyzer][solver] Track symbol disequalities
Summary:
This commmit adds another relation that we can track separately from
range constraints.  Symbol disequality can help us understand that
two equivalence classes are not equal to each other.  We can generalize
this knowledge to classes because for every a,b,c, and d that
a == b, c == d, and b != c it is true that a != d.

As a result, we can reason about other equalities/disequalities of symbols
that we know nothing else about, i.e. no constraint ranges associated
with them.  However, we also benefit from the knowledge of disequal
symbols by following the rule:
  if a != b and b == C where C is a constant, a != C
This information can refine associated ranges for different classes
and reduce the number of false positives and paths to explore.

Differential Revision: https://reviews.llvm.org/D83286
2020-07-22 13:02:39 +03:00
Valeriy Savchenko b13d9878b8 [analyzer][solver] Track symbol equivalence
Summary:
For the most cases, we try to reason about symbol either based on the
information we know about that symbol in particular or about its
composite parts.  This is faster and eliminates costly brute force
searches through existing constraints.

However, we do want to support some cases that are widespread enough
and involve reasoning about different existing constraints at once.
These include:
  * resoning about 'a - b' based on what we know about 'b - a'
  * reasoning about 'a <= b' based on what we know about 'a > b' or 'a < b'

This commit expands on that part by tracking symbols known to be equal
while still avoiding brute force searches.  It changes the way we track
constraints for individual symbols.  If we know for a fact that 'a == b'
then there is no need in tracking constraints for both 'a' and 'b' especially
if these constraints are different.  This additional relationship makes
dead/live logic for constraints harder as we want to maintain as much
information on the equivalence class as possible, but we still won't
carry the information that we don't need anymore.

Differential Revision: https://reviews.llvm.org/D82445
2020-07-22 13:02:39 +03:00
Valeriy Savchenko f531c1c7c0 [analyzer] Introduce small improvements to the solver infra
Summary:
* Add a new function to delete points from range sets.
* Introduce an internal generic interface for range set intersections.
* Remove unnecessary bits from a couple of solver functions.
* Add in-code sections.

Differential Revision: https://reviews.llvm.org/D82381
2020-07-22 13:02:39 +03:00
Nithin Vadukkumchery Rajendrakumar 76c0577763 [Analyzer] Handle unique_ptr::swap() in SmartPtrModeling
Summary:
    Implemented modeling for unique_ptr::swap() SmartPtrModeling

    Subscribers: xazax.hun, baloghadamsoftware, szepet, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, Charusso, martong, ASDenysPetrov, cfe-commits

    Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun
    Reviewed By: NoQ, vsavchenko, xazax.hun

    Tags: #clang

    Differential Revision: https://reviews.llvm.org/D8387
2020-07-21 12:05:27 +02:00
Nithin Vadukkumchery Rajendrakumar a560910211 [Analyzer] Add checkRegionChanges for SmartPtrModeling
Summary:
    Implemented checkRegionChanges for SmartPtrModeling

    Reviewers: NoQ, Szelethus, vsavchenko, xazax.hun

    Reviewed By: NoQ, vsavchenko, xazax.hun

    Subscribers: martong, cfe-commits
    Tags: #clang

    Differential Revision: https://reviews.llvm.org/D83836
2020-07-21 01:13:40 +02:00