This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
* Adds API support for widening of lattice elements and environments,
* Updates the algorithm to apply widening where appropriate,
* Implements widening for boolean values. In the process, moves the unsoundness
of comparison from the default implementation of
`Environment::ValueModel::compare` to model-specific handling inside
`DataflowEnvironment::equivalentTo`. This change is intended to clarify
the source and location of unsoundess.
This patch is a replacement for, and was based substantially on, https://reviews.llvm.org/D131645.
Differential Revision: https://reviews.llvm.org/D137948
This was done as a test for D137302 and it makes sense to push these changes
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D137491
Currently, the API for a model's custom value comparison returns a
boolean. Therefore, models cannot distinguish between situations where the
values are recognized by the model and different and those where the values are
just not recognized. This patch changes the return value to a tri-valued enum,
allowing models to express "don't know".
This patch is essentially a NFC -- no practical differences result from this
change in this patch. But, it prepares for future patches (particularly,
upcoming patches for widening) which will take advantage of the new flexibility.
Differential Revision: https://reviews.llvm.org/D137334
RISC-V vectors are basically vectors, but we use builtin types to
restrict the possible types. Treat them the same as vectors and scalars
for this analysis.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D136511
Defines an equivalence relation on the `Value` type to standardize several
places in the code where we replicate the ~same equivalence comparison.
Differential Revision: https://reviews.llvm.org/D135964
Some compilers can't determine that all cases of the switch return (or are
unreachable) and warn about control reaching end of non-void
function. Explicitly mark with `llvm_unreachable`.
Differential Revision: https://reviews.llvm.org/D135978
Currently, our boolean formulas (`BoolValue`) don't form a lattice, since they
have no Top element. This patch adds such an element, thereby "completing" the
built-in model of bools to be a proper semi-lattice. It still has infinite
height, which is its own problem, but that can be solved separately, through
widening and the like.
Patch 1 for Issue #56931.
Differential Revision: https://reviews.llvm.org/D135397
When support for copy elision was initially added in e97654b2f2, it
was taking attributes from a constructor call, although that constructor
call is actually not involved. It seems more natural to use attributes
on the function returning the scoped capability, which is where it's
actually coming from. This would also support a number of interesting
use cases, like producing different scope kinds without the need for tag
types, or producing scopes from a private mutex.
Changing the behavior was surprisingly difficult: we were not handling
CXXConstructorExpr calls like regular calls but instead handled them
through the DeclStmt they're contained in. This was based on the
assumption that constructors are basically only called in variable
declarations (not true because of temporaries), and that variable
declarations necessitate constructors (not true with C++17 anymore).
Untangling this required separating construction from assigning a
variable name. When a call produces an object, we use a placeholder
til::LiteralPtr for `this`, and we collect the call expression and
placeholder in a map. Later when going through a DeclStmt, we look up
the call expression and set the placeholder to the new VarDecl.
The change has a couple of nice side effects:
* We don't miss constructor calls not contained in DeclStmts anymore,
allowing patterns like
MutexLock{&mu}, requiresMutex();
The scoped lock temporary will be destructed at the end of the full
statement, so it protects the following call without the need for a
scope, but with the ability to unlock in case of an exception.
* We support lifetime extension of temporaries. While unusual, one can
now write
const MutexLock &scope = MutexLock(&mu);
and have it behave as expected.
* Destructors used to be handled in a weird way: since there is no
expression in the AST for implicit destructor calls, we instead
provided a made-up DeclRefExpr to the variable being destructed, and
passed that instead of a CallExpr. Then later in translateAttrExpr
there was special code that knew that destructor expressions worked a
bit different.
* We were producing dummy DeclRefExprs in a number of places, this has
been eliminated. We now use til::SExprs instead.
Technically this could break existing code, but the current handling
seems unexpected enough to justify this change.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D129755
This caused false positives, see comment on the code review.
> When support for copy elision was initially added in e97654b2f2, it
> was taking attributes from a constructor call, although that constructor
> call is actually not involved. It seems more natural to use attributes
> on the function returning the scoped capability, which is where it's
> actually coming from. This would also support a number of interesting
> use cases, like producing different scope kinds without the need for tag
> types, or producing scopes from a private mutex.
>
> Changing the behavior was surprisingly difficult: we were not handling
> CXXConstructorExpr calls like regular calls but instead handled them
> through the DeclStmt they're contained in. This was based on the
> assumption that constructors are basically only called in variable
> declarations (not true because of temporaries), and that variable
> declarations necessitate constructors (not true with C++17 anymore).
>
> Untangling this required separating construction from assigning a
> variable name. When a call produces an object, we use a placeholder
> til::LiteralPtr for `this`, and we collect the call expression and
> placeholder in a map. Later when going through a DeclStmt, we look up
> the call expression and set the placeholder to the new VarDecl.
>
> The change has a couple of nice side effects:
> * We don't miss constructor calls not contained in DeclStmts anymore,
> allowing patterns like
> MutexLock{&mu}, requiresMutex();
> The scoped lock temporary will be destructed at the end of the full
> statement, so it protects the following call without the need for a
> scope, but with the ability to unlock in case of an exception.
> * We support lifetime extension of temporaries. While unusual, one can
> now write
> const MutexLock &scope = MutexLock(&mu);
> and have it behave as expected.
> * Destructors used to be handled in a weird way: since there is no
> expression in the AST for implicit destructor calls, we instead
> provided a made-up DeclRefExpr to the variable being destructed, and
> passed that instead of a CallExpr. Then later in translateAttrExpr
> there was special code that knew that destructor expressions worked a
> bit different.
> * We were producing dummy DeclRefExprs in a number of places, this has
> been eliminated. We now use til::SExprs instead.
>
> Technically this could break existing code, but the current handling
> seems unexpected enough to justify this change.
>
> Reviewed By: aaron.ballman
>
> Differential Revision: https://reviews.llvm.org/D129755
This reverts commit 0041a69495 and the follow-up
warning fix in 83d93d3c11.
When support for copy elision was initially added in e97654b2f2, it
was taking attributes from a constructor call, although that constructor
call is actually not involved. It seems more natural to use attributes
on the function returning the scoped capability, which is where it's
actually coming from. This would also support a number of interesting
use cases, like producing different scope kinds without the need for tag
types, or producing scopes from a private mutex.
Changing the behavior was surprisingly difficult: we were not handling
CXXConstructorExpr calls like regular calls but instead handled them
through the DeclStmt they're contained in. This was based on the
assumption that constructors are basically only called in variable
declarations (not true because of temporaries), and that variable
declarations necessitate constructors (not true with C++17 anymore).
Untangling this required separating construction from assigning a
variable name. When a call produces an object, we use a placeholder
til::LiteralPtr for `this`, and we collect the call expression and
placeholder in a map. Later when going through a DeclStmt, we look up
the call expression and set the placeholder to the new VarDecl.
The change has a couple of nice side effects:
* We don't miss constructor calls not contained in DeclStmts anymore,
allowing patterns like
MutexLock{&mu}, requiresMutex();
The scoped lock temporary will be destructed at the end of the full
statement, so it protects the following call without the need for a
scope, but with the ability to unlock in case of an exception.
* We support lifetime extension of temporaries. While unusual, one can
now write
const MutexLock &scope = MutexLock(&mu);
and have it behave as expected.
* Destructors used to be handled in a weird way: since there is no
expression in the AST for implicit destructor calls, we instead
provided a made-up DeclRefExpr to the variable being destructed, and
passed that instead of a CallExpr. Then later in translateAttrExpr
there was special code that knew that destructor expressions worked a
bit different.
* We were producing dummy DeclRefExprs in a number of places, this has
been eliminated. We now use til::SExprs instead.
Technically this could break existing code, but the current handling
seems unexpected enough to justify this change.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D129755
We might have a CK_NoOp cast and a further CK_ConstructorConversion.
As an optimization, drop some IgnoreParens calls: inside of the
CK_{Constructor,UserDefined}Conversion should be no more parentheses,
and inside the CXXBindTemporaryExpr should also be none.
Lastly, we factor out the unpacking so that we can reuse it for
MaterializeTemporaryExprs later on.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D129752
This amends fd874e5fb1 to correctly set
the bit width of a '!' operator to be the same width as an 'int'. This
fixes a failed assertion about unexpected bit widths that was reported
during post-commit testing.
Extend the context-sensitive analysis to handle a call to a method (of the same
class) from within a method. That, is a member-call expression through `this`.
Differential Revision: https://reviews.llvm.org/D134432
To keep API of transfer functions consistent.
The single use of this transfer function in `ChromiumCheckModel` is also updated.
Reviewed By: gribozavr2, sgatev
Differential Revision: https://reviews.llvm.org/D133933
- Update `transfer` and `diagnose` to take `const CFGElement *` as input in `Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel`.
- Update `clang-tools-extra/clang-tidy/bugprone/UncheckedOptionalAccessCheck.cpp` accordingly.
- Rename `runDataflowAnalysisOnCFG` to `runDataflowAnalysis` and remove the deprecated `runDataflowAnalysis` (this was only used by the now updated optional check).
Reviewed By: gribozavr2, sgatev
Differential Revision: https://reviews.llvm.org/D133930
Previously, the transfer function `void transfer(const Stmt *, ...)` overriden by users is restricted to apply only on `CFGStmt`s and its contained `Stmt`.
By using a transfer function (`void transfer(const CFGElement *, ...)`) that takes a `CFGElement` as input, this patch extends user-defined analysis to all kinds of `CFGElement`. For example, users can now handle `CFGInitializer`s where `CXXCtorInitializer` AST nodes are contained.
Reviewed By: gribozavr2, sgatev
Differential Revision: https://reviews.llvm.org/D131614
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
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
The patch mainly focuses on the no warnings for -Wtautological-compare.
It work fine for the positive numbers but doesn't for the negative
numbers. This is because the warning explicitly checks for an
IntegerLiteral AST node, but -1 is represented by a UnaryOperator with
an IntegerLiteral sub-Expr.
Fixes#42918
Differential Revision: https://reviews.llvm.org/D130510
This patch adds a `Depth` field (default value 2) to `ContextSensitiveOptions`, allowing context-sensitive analysis of functions that call other functions. This also requires replacing the `DeclCtx` field on `Environment` with a `CallString` field that contains a vector of decl contexts, to ensure that the analysis doesn't try to analyze recursive or mutually recursive calls (which would result in a crash, due to the way we handle `StorageLocation`s).
Reviewed By: xazax.hun
Differential Revision: https://reviews.llvm.org/D131809
The point of a constexpr if statement is to determine which branch to
take at compile time, so warning on unreachable code is meaningless in
these situations.
Fixes#57123.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D131818
This patch restructures `DataflowAnalysisOptions` and `TransferOptions` to use `llvm::Optional`, in preparation for adding more sub-options to the `ContextSensitiveOptions` struct introduced here.
Reviewed By: sgatev, xazax.hun
Differential Revision: https://reviews.llvm.org/D131779
This patch modifies `Environment`'s `pushCall` method to pass over arguments that are missing storage locations, instead of crashing.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D131600
This patch adds the ability to context-sensitively analyze constructor bodies, by changing `pushCall` to allow both `CallExpr` and `CXXConstructExpr`, and extracting the main context-sensitive logic out of `VisitCallExpr` into a new `transferInlineCall` method which is now also called at the end of `VisitCXXConstructExpr`.
Reviewed By: ymandel, sgatev, xazax.hun
Differential Revision: https://reviews.llvm.org/D131438
This patch modifies `Environment`'s `pushCall` method to pass over arguments that are missing storage locations, instead of crashing.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D131600
This patch adds the ability to context-sensitively analyze constructor bodies, by changing `pushCall` to allow both `CallExpr` and `CXXConstructExpr`, and extracting the main context-sensitive logic out of `VisitCallExpr` into a new `transferInlineCall` method which is now also called at the end of `VisitCXXConstructExpr`.
Reviewed By: ymandel, sgatev, xazax.hun
Differential Revision: https://reviews.llvm.org/D131438
Kazu Hirata