Commit Graph

2843 Commits

Author SHA1 Message Date
Balazs Benics 7cddf9cad1 [analyzer] Dump the environment entry kind as well
By this change the `exploded-graph-rewriter` will display the class kind
of the expression of the environment entry. It makes easier to decide if
the given entry corresponds to the lvalue or to the rvalue of some
expression.

It turns out the rewriter already had support for visualizing it, but
probably was never actually used?

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D132109
2022-09-13 09:04:27 +02:00
Balazs Benics afcd862b2e [analyzer] LazyCompoundVals should be always bound as default bindings
`LazyCompoundVals` should only appear as `default` bindings in the
store. This fixes the second case in this patch-stack.

Depends on: D132142

Reviewed By: xazax.hun

Differential Revision: https://reviews.llvm.org/D132143
2022-09-13 08:58:46 +02:00
Balazs Benics f8643a9b31 [analyzer] Prefer wrapping SymbolicRegions by ElementRegions
It turns out that in certain cases `SymbolRegions` are wrapped by
`ElementRegions`; in others, it's not. This discrepancy can cause the
analyzer not to recognize if the two regions are actually referring to
the same entity, which then can lead to unreachable paths discovered.

Consider this example:

```lang=C++
struct Node { int* ptr; };
void with_structs(Node* n1) {
  Node c = *n1; // copy
  Node* n2 = &c;
  clang_analyzer_dump(*n1); // lazy...
  clang_analyzer_dump(*n2); // lazy...
  clang_analyzer_dump(n1->ptr); // rval(n1->ptr): reg_$2<int * SymRegion{reg_$0<struct Node * n1>}.ptr>
  clang_analyzer_dump(n2->ptr); // rval(n2->ptr): reg_$1<int * Element{SymRegion{reg_$0<struct Node * n1>},0 S64b,struct Node}.ptr>
  clang_analyzer_eval(n1->ptr != n2->ptr); // UNKNOWN, bad!
  (void)(*n1);
  (void)(*n2);
}
```

The copy of `n1` will insert a new binding to the store; but for doing
that it actually must create a `TypedValueRegion` which it could pass to
the `LazyCompoundVal`. Since the memregion in question is a
`SymbolicRegion` - which is untyped, it needs to first wrap it into an
`ElementRegion` basically implementing this untyped -> typed conversion
for the sake of passing it to the `LazyCompoundVal`.
So, this is why we have `Element{SymRegion{.}, 0,struct Node}` for `n1`.

The problem appears if the analyzer evaluates a read from the expression
`n1->ptr`. The same logic won't apply for `SymbolRegionValues`, since
they accept raw `SubRegions`, hence the `SymbolicRegion` won't be
wrapped into an `ElementRegion` in that case.

Later when we arrive at the equality comparison, we cannot prove that
they are equal.

For more details check the corresponding thread on discourse:
https://discourse.llvm.org/t/are-symbolicregions-really-untyped/64406

---

In this patch, I'm eagerly wrapping each `SymbolicRegion` by an
`ElementRegion`; basically canonicalizing to this form.
It seems reasonable to do so since any object can be thought of as a single
array of that object; so this should not make much of a difference.

The tests also underpin this assumption, as only a few were broken by
this change; and actually fixed a FIXME along the way.

About the second example, which does the same copy operation - but on
the heap - it will be fixed by the next patch.

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D132142
2022-09-13 08:58:46 +02:00
isuckatcs a11e51e91f [analyzer] Track trivial copy/move constructors and initializer lists in the BugReporter
If an object has a trivial copy/move constructor, it's not inlined
on invocation but a trivial copy is performed instead. This patch
handles trivial copies in the bug reporter by matching the field
regions of the 2 objects involved in the copy/move construction,
and tracking the appropriate region further. This patch also
introduces some support for tracking values in initializer lists.

Differential Revision: https://reviews.llvm.org/D131262
2022-09-05 17:06:27 +02:00
Kazu Hirata b7a7aeee90 [clang] Qualify auto in range-based for loops (NFC) 2022-09-03 23:27:27 -07:00
isuckatcs b5147937b2 [analyzer] Add more information to the Exploded Graph
This patch dumps every state trait in the egraph. Also
the empty state traits are no longer dumped, instead
they are treated as null by the egraph rewriter script,
which solves reverse compatibility issues.

Differential Revision: https://reviews.llvm.org/D131187
2022-09-03 00:21:05 +02:00
Martin Storsjö efc76a1ac5 [analyzer] Silence GCC warnings about unused variables. NFC.
Use `isa<T>()` instead of `Type *Var = dyn_cast<T>()`
when the result of the cast isn't used.
2022-08-29 13:26:13 +03:00
ziqingluo-90 a5e354ec4d [analyzer] Fixing a bug raising false positives of stack block object
leaking in ARC mode

When ARC (automatic reference count) is enabled, (objective-c) block
objects are automatically retained and released thus they do not leak.
Without ARC, they still can leak from an expiring stack frame like
other stack variables.
With this commit, the static analyzer now puts a block object in an
"unknown" region if ARC is enabled because it is up to the
implementation to choose whether to put the object on stack initially
(then move to heap when needed) or in heap directly under ARC.
Therefore, the `StackAddrEscapeChecker` has no need to know
specifically about ARC at all and it will not report errors on objects
in "unknown" regions.

Reviewed By: NoQ (Artem Dergachev)

Differential Revision: https://reviews.llvm.org/D131009
2022-08-26 12:19:32 -07:00
isuckatcs e3e9082b01 [analyzer] Fix for incorrect handling of 0 length non-POD array construction
Prior to this patch when the analyzer encountered a non-POD 0 length array,
it still invoked the constructor for 1 element, which lead to false positives.
This patch makes sure that we no longer construct any elements when we see a
0 length array.

Differential Revision: https://reviews.llvm.org/D131501
2022-08-25 12:42:02 +02:00
isuckatcs aac73a31ad [analyzer] Process non-POD array element destructors
The constructors of non-POD array elements are evaluated under
certain conditions. This patch makes sure that in such cases
we also evaluate the destructors.

Differential Revision: https://reviews.llvm.org/D130737
2022-08-24 01:28:21 +02:00
isuckatcs c81bf940c7 [analyzer] Handling non-POD multidimensional arrays in ArrayInitLoopExpr
This patch makes it possible for lambdas, implicit copy/move ctors
and structured bindings to handle non-POD multidimensional arrays.

Differential Revision: https://reviews.llvm.org/D131840
2022-08-22 13:53:53 +02:00
isuckatcs 3c482632e6 [analyzer] Remove pattern matching of lambda capture initializers
Prior to this patch we handled lambda captures based on their
initializer expression, which resulted in pattern matching. With
C++17 copy elision the initializer expression can be anything,
and this approach proved to be fragile and a source of crashes.
This patch removes pattern matching and only checks whether the
object is under construction or not.

Differential Revision: https://reviews.llvm.org/D131944
2022-08-22 13:00:31 +02:00
isuckatcs a47ec1b797 [analyzer][NFC] Be more descriptive when we replay without inlining
This patch adds a ProgramPointTag to the EpsilonPoint created
before we replay a call without inlining.

Differential Revision: https://reviews.llvm.org/D132246
2022-08-19 18:05:52 +02:00
isuckatcs b4e3e3a3eb [analyzer] Fix a crash on copy elided initialized lambda captures
Inside `ExprEngine::VisitLambdaExpr()` we wasn't prepared for a
copy elided initialized capture's `InitExpr`. This patch teaches
the analyzer how to handle such situation.

Differential Revision: https://reviews.llvm.org/D131784
2022-08-13 00:22:01 +02:00
Denys Petrov adcd4b1c0b [analyzer] [NFC] Fix comments into more regular form. 2022-08-11 21:28:23 +03:00
Fangrui Song 32197830ef [clang][clang-tools-extra] LLVM_NODISCARD => [[nodiscard]]. NFC 2022-08-09 07:11:18 +00:00
Fangrui Song 3f18f7c007 [clang] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D131346
2022-08-08 09:12:46 -07:00
Corentin Jabot 127bf44385 [Clang][C++20] Support capturing structured bindings in lambdas
This completes the implementation of P1091R3 and P1381R1.

This patch allow the capture of structured bindings
both for C++20+ and C++17, with extension/compat warning.

In addition, capturing an anonymous union member,
a bitfield, or a structured binding thereof now has a
better diagnostic.

We only support structured bindings - as opposed to other kinds
of structured statements/blocks. We still emit an error for those.

In addition, support for structured bindings capture is entirely disabled in
OpenMP mode as this needs more investigation - a specific diagnostic indicate the feature is not yet supported there.

Note that the rest of P1091R3 (static/thread_local structured bindings) was already implemented.

at the request of @shafik, i can confirm the correct behavior of lldb wit this change.

Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/52720

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122768
2022-08-04 10:12:53 +02:00
Corentin Jabot a274219600 Revert "[Clang][C++20] Support capturing structured bindings in lambdas"
This reverts commit 44f2baa380.

Breaks self builds and seems to have conformance issues.
2022-08-03 21:00:29 +02:00
Corentin Jabot 44f2baa380 [Clang][C++20] Support capturing structured bindings in lambdas
This completes the implementation of P1091R3 and P1381R1.

This patch allow the capture of structured bindings
both for C++20+ and C++17, with extension/compat warning.

In addition, capturing an anonymous union member,
a bitfield, or a structured binding thereof now has a
better diagnostic.

We only support structured bindings - as opposed to other kinds
of structured statements/blocks. We still emit an error for those.

In addition, support for structured bindings capture is entirely disabled in
OpenMP mode as this needs more investigation - a specific diagnostic indicate the feature is not yet supported there.

Note that the rest of P1091R3 (static/thread_local structured bindings) was already implemented.

at the request of @shafik, i can confirm the correct behavior of lldb wit this change.

Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/54300
Fixes https://github.com/llvm/llvm-project/issues/52720

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122768
2022-08-03 20:00:01 +02:00
isuckatcs 10a7ee0bac [analyzer] Fix for the crash in #56873
In ExprEngine::bindReturnValue() we cast an SVal to DefinedOrUnknownSVal,
however this SVal can also be Undefined, which leads to an assertion failure.

Fixes: #56873

Differential Revision: https://reviews.llvm.org/D130974
2022-08-03 19:25:02 +02:00
Gabriel Ravier 5674a3c880 Fixed a number of typos
I went over the output of the following mess of a command:

(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z |
 parallel --xargs -0 cat | aspell list --mode=none --ignore-case |
 grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n |
 grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)

and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).

Differential Revision: https://reviews.llvm.org/D130827
2022-08-01 13:13:18 -04:00
Chuanqi Xu 5588985212 [NFC] Convert a dyn_cast<> to an isa<> 2022-07-27 13:56:38 +08:00
Balazs Benics a80418eec0 [analyzer] Improve loads from reinterpret-cast fields
Consider this example:

```lang=C++
struct header {
  unsigned a : 1;
  unsigned b : 1;
};
struct parse_t {
  unsigned bits0 : 1;
  unsigned bits2 : 2; // <-- header
  unsigned bits4 : 4;
};
int parse(parse_t *p) {
  unsigned copy = p->bits2;
  clang_analyzer_dump(copy);
  // expected-warning@-1 {{reg_$1<unsigned int SymRegion{reg_$0<struct Bug_55934::parse_t * p>}.bits2>}}

  header *bits = (header *)&copy;
  clang_analyzer_dump(bits->b); // <--- Was UndefinedVal previously.
  // expected-warning@-1 {{derived_$2{reg_$1<unsigned int SymRegion{reg_$0<struct Bug_55934::parse_t * p>}.bits2>,Element{copy,0 S64b,struct Bug_55934::header}.b}}}
  return bits->b; // no-warning: it's not UndefinedVal
}
```

`bits->b` should have the same content as the second bit of `p->bits2`
(assuming that the bitfields are in spelling order).

---

The `Store` has the correct bindings. The problem is with the load of `bits->b`.
It will eventually reach `RegionStoreManager::getBindingForField()` with
`Element{copy,0 S64b,struct header}.b`, which is a `FieldRegion`.
It did not find any direct bindings, so the `getBindingForFieldOrElementCommon()`
gets called. That won't find any bindings, but it sees that the variable
is on the //stack//, thus it must be an uninitialized local variable;
thus it returns `UndefinedVal`.

Instead of doing this, it should have created a //derived symbol//
representing the slice of the region corresponding to the member.
So, if the value of `copy` is `reg1`, then the value of `bits->b` should
be `derived{reg1, elem{copy,0, header}.b}`.

Actually, the `getBindingForElement()` already does exactly this for
reinterpret-casts, so I decided to hoist that and reuse the logic.

Fixes #55934

Reviewed By: martong

Differential Revision: https://reviews.llvm.org/D128535
2022-07-26 12:31:21 +02:00
Benjamin Kramer ad17e69923 [analyzer] Fix unused variable warning in release builds. NFC. 2022-07-26 11:29:38 +02:00
David Spickett f3fbbe1cf3 [clang][analyzer][NFC] Use value_or instead of ValueOr
The latter is deprecated.
2022-07-26 09:16:45 +00:00
isuckatcs a618d5e0dd [analyzer] Structured binding to tuple-like types
Introducing support for creating structured binding
to tuple-like types.

Differential Revision: https://reviews.llvm.org/D128837
2022-07-26 10:24:29 +02:00
isuckatcs 996b092c5e [analyzer] Lambda capture non-POD type array
This patch introduces a new `ConstructionContext` for
lambda capture. This `ConstructionContext` allows the
analyzer to construct the captured object directly into
it's final region, and makes it possible to capture
non-POD arrays.

Differential Revision: https://reviews.llvm.org/D129967
2022-07-26 09:40:25 +02:00
isuckatcs 8a13326d18 [analyzer] ArrayInitLoopExpr with array of non-POD type
This patch introduces the evaluation of ArrayInitLoopExpr
in case of structured bindings and implicit copy/move
constructor. The idea is to call the copy constructor for
every element in the array. The parameter of the copy
constructor is also manually selected, as it is not a part
of the CFG.

Differential Revision: https://reviews.llvm.org/D129496
2022-07-26 09:07:22 +02:00
Kazu Hirata 3f3930a451 Remove redundaunt virtual specifiers (NFC)
Identified with tidy-modernize-use-override.
2022-07-25 23:00:59 -07:00
Kazu Hirata ae002f8bca Use isa instead of dyn_cast (NFC) 2022-07-25 23:00:58 -07:00
Kazu Hirata 95a932fb15 Remove redundaunt override specifiers (NFC)
Identified with modernize-use-override.
2022-07-24 22:28:11 -07:00
Denys Petrov a364987368 [analyzer][NFC] Use `SValVisitor` instead of explicit helper functions
Summary: Get rid of explicit function splitting in favor of specifically designed Visitor. Move logic from a family of `evalCastKind` and `evalCastSubKind` helper functions to `SValVisitor`.

Differential Revision: https://reviews.llvm.org/D130029
2022-07-19 23:10:00 +03:00
serge-sans-paille f764dc99b3 [clang] Introduce -fstrict-flex-arrays=<n> for stricter handling of flexible arrays
Some code [0] consider that trailing arrays are flexible, whatever their size.
Support for these legacy code has been introduced in
f8f6324983 but it prevents evaluation of
__builtin_object_size and __builtin_dynamic_object_size in some legit cases.

Introduce -fstrict-flex-arrays=<n> to have stricter conformance when it is
desirable.

n = 0: current behavior, any trailing array member is a flexible array. The default.
n = 1: any trailing array member of undefined, 0 or 1 size is a flexible array member
n = 2: any trailing array member of undefined or 0 size is a flexible array member

This takes into account two specificities of clang: array bounds as macro id
disqualify FAM, as well as non standard layout.

Similar patch for gcc discuss here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836

[0] https://docs.freebsd.org/en/books/developers-handbook/sockets/#sockets-essential-functions
2022-07-18 12:45:52 +02:00
Denys Petrov bc08c3cb7f [analyzer] Add new function `clang_analyzer_value` to ExprInspectionChecker
Summary: Introduce a new function 'clang_analyzer_value'. It emits a report that in turn prints a RangeSet or APSInt associated with SVal. If there is no associated value, prints "n/a".
2022-07-15 20:07:04 +03:00
Denys Petrov 82f76c0477 [analyzer][NFC] Tidy up handler-functions in SymbolicRangeInferrer
Summary: Sorted some handler-functions into more appropriate visitor functions of the SymbolicRangeInferrer.
- Spread `getRangeForNegatedSub` body over several visitor functions: `VisitSymExpr`, `VisitSymIntExpr`, `VisitSymSymExpr`.
- Moved `getRangeForComparisonSymbol` from `infer` to `VisitSymSymExpr`.

Differential Revision: https://reviews.llvm.org/D129678
2022-07-15 19:24:57 +03:00
Fangrui Song 3c849d0aef Modernize Optional::{getValueOr,hasValue} 2022-07-15 01:20:39 -07:00
isuckatcs b032e3ff61 [analyzer] Evaluate construction of non-POD type arrays
Introducing the support for evaluating the constructor
of every element in an array. The idea is to record the
index of the current array member being constructed and
create a loop during the analysis. We looping over the
same CXXConstructExpr as many times as many elements
the array has.

Differential Revision: https://reviews.llvm.org/D127973
2022-07-14 23:30:21 +02:00
Ella Ma 32fe1a4be9 [analyzer] Fixing SVal::getType returns Null Type for NonLoc::ConcreteInt in boolean type
In method `TypeRetrievingVisitor::VisitConcreteInt`, `ASTContext::getIntTypeForBitwidth` is used to get the type for `ConcreteInt`s.
However, the getter in ASTContext cannot handle the boolean type with the bit width of 1, which will make method `SVal::getType` return a Null `Type`.
In this patch, a check for this case is added to fix this problem by returning the bool type directly when the bit width is 1.

Differential Revision: https://reviews.llvm.org/D129737
2022-07-14 22:00:38 +08:00
Kazu Hirata cb2c8f694d [clang] Use value instead of getValue (NFC) 2022-07-13 23:39:33 -07:00
Kazu Hirata 53daa177f8 [clang, clang-tools-extra] Use has_value instead of hasValue (NFC) 2022-07-12 22:47:41 -07:00
Gabor Marton 2df120784a [analyzer] Fix assertion in simplifySymbolCast
Depends on D128068.
Added a new test code that fails an assertion in the baseline.
That is because `getAPSIntType` works only with integral types.

Differential Revision: https://reviews.llvm.org/D126779
2022-07-05 19:00:23 +02:00
Gabor Marton 5d7fa481cf [analyzer] Do not emit redundant SymbolCasts
In `RegionStore::getBinding` we call `evalCast` unconditionally to align
the stored value's type to the one that is being queried. However, the
stored type might be the same, so we may end up having redundant
`SymbolCasts` emitted.

The solution is to check whether the `to` and `from` type are the same
in `makeNonLoc`.

Note, we can't just do type equivalence check at the beginning of `evalCast`
because when `evalCast` is called from `getBinding` then the original type
(`OriginalTy`) is not set, so one operand is missing for the comparison. In
`evalCastSubKind(nonloc::SymbolVal)` when the original type is not set,
we get the `from` type via `SymbolVal::getType()`.

Differential Revision: https://reviews.llvm.org/D128068
2022-07-05 18:42:34 +02:00
Fazlay Rabbi 38bcd483dd [OpenMP] Initial parsing and semantic support for 'parallel masked taskloop simd' construct
This patch gives basic parsing and semantic support for
"parallel masked taskloop simd" construct introduced in
OpenMP 5.1 (section 2.16.10)

Differential Revision: https://reviews.llvm.org/D128946
2022-07-01 08:57:15 -07:00
Fazlay Rabbi d64ba896d3 [OpenMP] Initial parsing and sema support for 'parallel masked taskloop' construct
This patch gives basic parsing and semantic support for
"parallel masked taskloop" construct introduced in
OpenMP 5.1 (section 2.16.9)

Differential Revision: https://reviews.llvm.org/D128834
2022-06-30 11:44:17 -07:00
isuckatcs 9d2e830737 [analyzer] Fix BindingDecl evaluation for reference types
The case when the bound variable is reference type in a
BindingDecl wasn't handled, which lead to false positives.

Differential Revision: https://reviews.llvm.org/D128716
2022-06-29 13:01:19 +02:00
Fazlay Rabbi 73e5d7bdff [OpenMP] Initial parsing and sema support for 'masked taskloop simd' construct
This patch gives basic parsing and semantic support for
"masked taskloop simd" construct introduced in OpenMP 5.1 (section 2.16.8)

Differential Revision: https://reviews.llvm.org/D128693
2022-06-28 15:27:49 -07:00
Vitaly Buka cdfa15da94 Revert "[clang] Introduce -fstrict-flex-arrays=<n> for stricter handling of flexible arrays"
This reverts D126864 and related fixes.

This reverts commit 572b08790a.
This reverts commit 886715af96.
2022-06-27 14:03:09 -07:00
Kazu Hirata 97afce08cb [clang] Don't use Optional::hasValue (NFC)
This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.
2022-06-25 22:26:24 -07:00
Kazu Hirata 3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3.
2022-06-25 11:56:50 -07:00