function declaration.
We'd previously often just drop these on the floor, and friend
redeclaration matching would usually (but not always) figure out the
right redeclaration anyway.
Also, don't try to match a dependent friend function template
specialization to a template until instantiation, and don't forget to
reject qualified friend declarations in dependent contexts that don't
name an already-declared entity.
llvm-svn: 350915
Summary:
https://reviews.llvm.org/D54862 removed the usages of `ASTContext&` from
within the `CXXMethodDecl::getThisType` method. Remove the parameter
altogether, as well as all usages of it. This does not result in any
functional change because the parameter was unused since
https://reviews.llvm.org/D54862.
Test Plan: check-clang
Reviewers: akyrtzi, mikael
Reviewed By: mikael
Subscribers: mehdi_amini, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D56509
llvm-svn: 350914
placeholder expressions while an unevaluated context is still on the
expression evaluation context stack.
This prevents recordUseOfWeek from being called when a weak variable is
used as an operand of a decltype or a typeof expression and fixes
spurious -Warc-repeated-use-of-weak warnings.
rdar://problem/45742525
Differential Revision: https://reviews.llvm.org/D55662
llvm-svn: 350887
Summary: In the [expr.sub] p1, we can read that for a given E1[E2], E1 is sequenced before E2.
Patch by Mateusz Janek.
Reviewers: rsmith, Rakete1111
Reviewed By: rsmith, Rakete1111
Subscribers: riccibruno, lebedev.ri, Rakete1111, hiraditya, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D50766
llvm-svn: 350874
Summary:
Prevents -Wunneeded-internal-delcaration warnings when the target has no
other references. This occurs frequently in device drivers in the Linux
kernel.
Sema would need to invoke the demangler on the target, since in C++ the
target name is mangled:
int f() { return 42; }
int g() __attribute__((alias("_Z1fv")));
Sema does not have the ability to demangle names at this time.
https://bugs.llvm.org/show_bug.cgi?id=39088https://github.com/ClangBuiltLinux/linux/issues/232
Reviewers: rsmith, rjmccall
Reviewed By: rsmith
Subscribers: erik.pilkington, cfe-commits, pirama, srhines
Differential Revision: https://reviews.llvm.org/D54188
llvm-svn: 350776
the @implementation context
In Objective-C, it's common for some frameworks to mark some methods like init
as unavailable in the @interface to prohibit their usage. However, these
frameworks then often implemented said method and refer to it in another method
that acts as a factory for that object. The recent change to how messages to
self are type checked in clang (r349841) introduced a regression which started
to prohibit this pattern with an X is unavailable error. This commit addresses
the aforementioned regression.
rdar://47134898
Differential Revision: https://reviews.llvm.org/D56469
llvm-svn: 350768
Summary: Change the strategy for computing loop index variables after collapsing a loop nest via the collapse clause by replacing the expensive remainder operation with multiplications and additions.
Reviewers: ABataev, caomhin
Reviewed By: ABataev
Subscribers: guansong, arphaman, cfe-commits
Differential Revision: https://reviews.llvm.org/D56413
llvm-svn: 350759
Summary: Introduce a compiler flag for cases when the user knows that the collapsed loop counter can be safely represented using at most 32 bits. This will prevent the emission of expensive mathematical operations (such as the div operation) on the iteration variable using 64 bits where 32 bit operations are sufficient.
Reviewers: ABataev, caomhin
Reviewed By: ABataev
Subscribers: hfinkel, kkwli0, guansong, cfe-commits
Differential Revision: https://reviews.llvm.org/D55928
llvm-svn: 350758
Summary:
There is a minor issue in how the implicit data-sharings for nested tasks are computed.
For the following example:
```
int x;
#pragma omp task shared(x)
#pragma omp task
x++;
```
We compute an implicit data-sharing of shared for `x` in the second task although I think that it should be firstprivate. Below you can find the part of the OpenMP spec that covers this example:
- // In a task generating construct, if no default clause is present, a variable for which the data-sharing attribute is not determined by the rules above and that in the enclosing context is determined to be shared by all implicit tasks bound to the current team is shared.//
- //In a task generating construct, if no default clause is present, a variable for which the data-sharing attribute is not determined by the rules above is firstprivate.//
Since each implicit-task has its own copy of `x`, we shouldn't apply the first rule.
Reviewers: ABataev
Reviewed By: ABataev
Subscribers: cfe-commits, rogfer01
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D56430
llvm-svn: 350734
Rather than duplicating data fields, use DeclSpec directly to store
the qualifiers for the functions/methods. This change doesn't handle
attributes yet and has to be extended further.
Differential revision: https://reviews.llvm.org/D55948
llvm-svn: 350703
When the type of the base expression after IgnoreParenCasts is incomplete,
it is still possible to diagnose an array access which precedes the array
bounds.
This is a follow-up on D55862 which added an early return when the type of
the base expression after IgnoreParenCasts was incomplete.
Differential Revision: https://reviews.llvm.org/D56050
Reviewed By: efriedma
llvm-svn: 350622
Store the optional array size expression, optional initialization expression
and optional placement new arguments in a trailing array. Additionally store
the range for the parenthesized type-id in a trailing object if needed since
in the vast majority of cases the type is not parenthesized (not a single new
expression in the translation unit of SemaDecl.cpp has a parenthesized type-id).
This saves 2 pointers per CXXNewExpr in all cases, and 2 pointers + 8 bytes
per CXXNewExpr in the common case where the type is not parenthesized.
Differential Revision: https://reviews.llvm.org/D56134
Reviewed By: rjmccall
llvm-svn: 350527
template specialization if there is no matching non-template function.
This exposed a couple of related bugs:
- we would sometimes substitute into a friend template instead of a
suitable non-friend declaration; this would now crash because we'd
decide the specialization of the friend is a redeclaration of itself
- ADL failed to properly handle the case where an invisible local
extern declaration redeclares an invisible friend
Both are fixed herein: in particular, we now never make invisible
friends or local extern declarations visible to name lookup unless
they are the only declaration of the entity. (We already mostly did
this for local extern declarations.)
llvm-svn: 350505
Summary:
The documentation for RecursiveASTVisitor::TraverseDecl states that the
Decl being traversed may be null. In fact, this is the case when a
CXXCatchStmt with no exception decl is traversed. Because the visitor
for diagnosing unexpanded parameter packs does not check for null, it
ends up crashing when it attempts to call the Decl::isParameterPack
method on a null Decl pointer.
Add a null check to prevent an ICE, and a test case that would crash
otherwise. Also, because the test requires C++ exceptions and C++14,
change the test parameters for the entire test file. (Alternatively, I
thought about adding a new test file, but went with this approach for my
own convenience.)
Co-authored-by: Andreas Molzer <andreas.molzer@gmx.de>
Co-authored-by: Mara Bos <m-ou.se@m-ou.se>
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D56271
llvm-svn: 350501
As discussed in D56113, this patch refactors the implementation of the
const restriction for linear to reuse a function introduced by D56113.
A side effect is that, if a variable has mutable members, this
diagnostic is now skipped, and the diagnostic for the variable not
being an integer or pointer is reported instead.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D56299
llvm-svn: 350441
As discussed in D56113, this patch refactors the implementation of the
const restriction for reductions to reuse a function introduced by
D56113. A side effect is that diagnostics sometimes now say
"variable" instead of "list item" when a list item is a variable.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D56298
llvm-svn: 350440
The following appears in OpenMP 3.1 sec. 2.9.1.1 as a predetermined
data-sharing attribute:
> Variables with const-qualified type having no mutable member are
> shared.
It does not appear in OpenmP 4.0, 4.5, or 5.0. This patch removes the
implementation of that attribute when the requested OpenMP version is
greater than 3.1.
One effect of that removal is that `default(none)` affects const
variables without mutable members.
Also, without this patch, if a const variable without mutable members
was explicitly lastprivate or private, it was an error because it was
predetermined shared. Now, clang instead complains that it's const
without mutable fields, which is a more intelligible diagnostic. That
should be fine for all of the above versions because they all have
something like the following, which is quoted from OpenMP 5.0
sec. 2.19.3:
> A variable that is privatized must not have a const-qualified type
> unless it is of class type with a mutable member. This restriction does
> not apply to the firstprivate clause.
reduction and linear clauses already have separate checks for const
variables. Future patches will merge the implementations.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D56113
llvm-svn: 350439
This attribute, called "objc_externally_retained", exposes clang's
notion of pseudo-__strong variables in ARC. Pseudo-strong variables
"borrow" their initializer, meaning that they don't retain/release
it, instead assuming that someone else is keeping their value alive.
If a function is annotated with this attribute, implicitly strong
parameters of that function aren't implicitly retained/released in
the function body, and are implicitly const. This is useful to expose
for performance reasons, most functions don't need the extra safety
of the retain/release, so programmers can opt out as needed.
This attribute can also apply to declarations of local variables,
with similar effect.
Differential revision: https://reviews.llvm.org/D55865
llvm-svn: 350422
This patch adds #pragma clang loop pipeline and #pragma clang loop pipeline_initiation_interval for debugging or reducing compile time purposes. It is possible to disable SWP for concrete loops to save compilation time or to find bugs by not doing SWP to certain loops. It is possible to set value of initiation interval to concrete number to save compilation time by not doing extra pipeliner passes or to check created schedule for specific initiation interval.
Patch by Alexey Lapshin.
llvm-svn: 350414
Rather than sprinkle calls to DiagnoseUnusedExprResult() around in places where we want diagnostics, we now diagnose unused expression statements and full expressions in a more generic way when acting on the final expression statement. This results in more appropriate diagnostics for [[nodiscard]] where we were previously lacking them, such as when the body of a for loop is not a compound statement.
This patch fixes PR39837.
llvm-svn: 350404
CPUSpecifc/CPUDispatch call resolution assumed that all declarations
that would be passed are valid, however this was an invalid assumption.
This patch deals with those situations by making the valid version take
priority. Note that the checked ordering is arbitrary, since both are
replaced by calls to the resolver later.
Change-Id: I7ff2ec88c55a721d51bc1f39ea1a1fe242b4e45f
llvm-svn: 350398
Qualifiers can now be streamed into the DiagnosticEngine using
regular << operator. If Qualifiers are empty 'unqualified' will
be printed in the diagnostic otherwise regular qual syntax is
used.
Differential Revision: https://reviews.llvm.org/D56198
llvm-svn: 350386
When a function returns a type and that type was declared [[nodiscard]], we diagnose any unused results from that call as though the function were marked nodiscard. The same behavior should apply to calls through a function pointer.
This addresses PR31526.
llvm-svn: 350317
For constants with the predefined data-sharing clauses we may had
troubles with the target combined directives. It may cause compiler
crash in some corner cases.
llvm-svn: 350127
Store the arguments of CXXConstructExpr in a trailing array. This is very
similar to the CallExpr case in D55771, with the exception that there is
only one derived class (CXXTemporaryObjectExpr) and that we compute the
offset to the trailing array instead of storing it.
This saves one pointer per CXXConstructExpr and CXXTemporaryObjectExpr.
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D56022
llvm-svn: 350003
Since CallExpr::setNumArgs has been removed, it is now possible to store the
callee expression and the argument expressions of CallExpr in a trailing array.
This saves one pointer per CallExpr, CXXOperatorCallExpr, CXXMemberCallExpr,
CUDAKernelCallExpr and UserDefinedLiteral.
Given that CallExpr is used as a base of the above classes we cannot use
llvm::TrailingObjects. Instead we store the offset in bytes from the this pointer
to the start of the trailing objects and manually do the casts + arithmetic.
Some notes:
1.) I did not try to fit the number of arguments in the bit-fields of Stmt.
This leaves some space for future additions and avoid the discussion about
whether x bits are sufficient to hold the number of arguments.
2.) It would be perfectly possible to recompute the offset to the trailing
objects before accessing the trailing objects. However the trailing objects
are frequently accessed and benchmarks show that it is slightly faster to
just load the offset from the bit-fields. Additionally, because of 1),
we have plenty of space in the bit-fields of Stmt.
Differential Revision: https://reviews.llvm.org/D55771
Reviewed By: rjmccall
llvm-svn: 349910
All of the other constructors already take a reference to the AST context.
This avoids calling Decl::getASTContext in most cases. Additionally move
the definition of the constructor from Expr.h to Expr.cpp since it is calling
DeclRefExpr::computeDependence. NFC.
llvm-svn: 349901
functions that are unavailable on Darwin are explicitly called or called
from deleting destructors.
rdar://problem/40736230
Differential Revision: https://reviews.llvm.org/D47757
llvm-svn: 349890
Namespaces are introduced by adding an "identifier." before a
push/pop directive. Pop directives with namespaces can only pop a
attribute group that was pushed with the same namespace. Push and pop
directives that don't opt into namespaces have the same semantics.
This is necessary to prevent a pitfall of using multiple #pragma
clang attribute directives spread out in a large file, particularly
when macros are involved. It isn't easy to see which pop corripsonds
to which push, so its easy to inadvertently pop the wrong group.
Differential revision: https://reviews.llvm.org/D55628
llvm-svn: 349845
use the pointer to the class as the result type of the message
Prior to this commit, messages to self in class methods were treated as instance
methods to a Class value. When these methods returned instancetype the compiler
only saw id through the instancetype, and not the Interface *. This caused
problems when that return value was a receiver in a message send, as the
compiler couldn't select the right method declaration and had to rely on a
selection from the global method pool.
This commit modifies the semantics of such message sends and uses class messages
that are dispatched to the interface that corresponds to the class that contains
the class method. This ensures that instancetypes are correctly interpreted by
the compiler. This change is safe under ARC (as self can't be reassigned),
however, it also applies to MRR code as we are assuming that the user isn't
doing anything unreasonable.
rdar://20940997
Differential Revision: https://reviews.llvm.org/D36790
llvm-svn: 349841
When checking that the array access is not out-of-bounds in CheckArrayAccess
it is possible that the type of the base expression after IgnoreParenCasts is
incomplete, even though the type of the base expression before IgnoreParenCasts
is complete. In this case we have no information about whether the array access
is out-of-bounds and we should just bail-out instead. This fixes PR39746 which
was caused by trying to obtain the size of an incomplete type.
Differential Revision: https://reviews.llvm.org/D55862
Reviewed By: efriedma
llvm-svn: 349811
Need to mark the loop as started when the initialization statement is
found. It is required to prevent possible incorrect loop iteraton
variable detection during template instantiation and fix the compiler
crash during the codegen.
llvm-svn: 349657
Summary:
The clang used to pick up the qualifiers of the lamba's call operator
(which is always const) and fail to show non-const methods of 'this' in
completion results.
Reviewers: kadircet
Reviewed By: kadircet
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D55885
llvm-svn: 349655
Without this patch, clang doesn't complain that X needs explicit data
sharing attributes in the following:
```
#pragma omp target teams default(none)
{
#pragma omp parallel num_threads(X)
;
}
```
However, clang does produce that complaint after the braces are
removed. With this patch, clang complains in both cases.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D55861
llvm-svn: 349635
Summary:
Some ASM input constraints (e.g., "i" and "n") require immediate values. At O0,
very few code transformations are performed. So if we cannot resolve to an
immediate when emitting the ASM input we shouldn't delay its processing.
Reviewers: rsmith, efriedma
Reviewed By: efriedma
Subscribers: rehana, efriedma, craig.topper, jyknight, cfe-commits
Differential Revision: https://reviews.llvm.org/D55616
llvm-svn: 349561
A map clause with the close map-type-modifier is a hint to
prefer that the variables are mapped using a copy into faster
memory.
Patch by Ahsan Saghir (saghir)
Differential Revision: https://reviews.llvm.org/D55719
llvm-svn: 349551
Only explicitly look through integer and floating-point promotion where the result type is actually a promotion, which is not always the case for bit-fields in C.
Patch by Bevin Hansson.
llvm-svn: 349497
Summary:
Add an option to initialize automatic variables with either a pattern or with
zeroes. The default is still that automatic variables are uninitialized. Also
add attributes to request uninitialized on a per-variable basis, mainly to disable
initialization of large stack arrays when deemed too expensive.
This isn't meant to change the semantics of C and C++. Rather, it's meant to be
a last-resort when programmers inadvertently have some undefined behavior in
their code. This patch aims to make undefined behavior hurt less, which
security-minded people will be very happy about. Notably, this means that
there's no inadvertent information leak when:
- The compiler re-uses stack slots, and a value is used uninitialized.
- The compiler re-uses a register, and a value is used uninitialized.
- Stack structs / arrays / unions with padding are copied.
This patch only addresses stack and register information leaks. There's many
more infoleaks that we could address, and much more undefined behavior that
could be tamed. Let's keep this patch focused, and I'm happy to address related
issues elsewhere.
To keep the patch simple, only some `undef` is removed for now, see
`replaceUndef`. The padding-related infoleaks are therefore not all gone yet.
This will be addressed in a follow-up, mainly because addressing padding-related
leaks should be a stand-alone option which is implied by variable
initialization.
There are three options when it comes to automatic variable initialization:
0. Uninitialized
This is C and C++'s default. It's not changing. Depending on code
generation, a programmer who runs into undefined behavior by using an
uninialized automatic variable may observe any previous value (including
program secrets), or any value which the compiler saw fit to materialize on
the stack or in a register (this could be to synthesize an immediate, to
refer to code or data locations, to generate cookies, etc).
1. Pattern initialization
This is the recommended initialization approach. Pattern initialization's
goal is to initialize automatic variables with values which will likely
transform logic bugs into crashes down the line, are easily recognizable in
a crash dump, without being values which programmers can rely on for useful
program semantics. At the same time, pattern initialization tries to
generate code which will optimize well. You'll find the following details in
`patternFor`:
- Integers are initialized with repeated 0xAA bytes (infinite scream).
- Vectors of integers are also initialized with infinite scream.
- Pointers are initialized with infinite scream on 64-bit platforms because
it's an unmappable pointer value on architectures I'm aware of. Pointers
are initialize to 0x000000AA (small scream) on 32-bit platforms because
32-bit platforms don't consistently offer unmappable pages. When they do
it's usually the zero page. As people try this out, I expect that we'll
want to allow different platforms to customize this, let's do so later.
- Vectors of pointers are initialized the same way pointers are.
- Floating point values and vectors are initialized with a negative quiet
NaN with repeated 0xFF payload (e.g. 0xffffffff and 0xffffffffffffffff).
NaNs are nice (here, anways) because they propagate on arithmetic, making
it more likely that entire computations become NaN when a single
uninitialized value sneaks in.
- Arrays are initialized to their homogeneous elements' initialization
value, repeated. Stack-based Variable-Length Arrays (VLAs) are
runtime-initialized to the allocated size (no effort is made for negative
size, but zero-sized VLAs are untouched even if technically undefined).
- Structs are initialized to their heterogeneous element's initialization
values. Zero-size structs are initialized as 0xAA since they're allocated
a single byte.
- Unions are initialized using the initialization for the largest member of
the union.
Expect the values used for pattern initialization to change over time, as we
refine heuristics (both for performance and security). The goal is truly to
avoid injecting semantics into undefined behavior, and we should be
comfortable changing these values when there's a worthwhile point in doing
so.
Why so much infinite scream? Repeated byte patterns tend to be easy to
synthesize on most architectures, and otherwise memset is usually very
efficient. For values which aren't entirely repeated byte patterns, LLVM
will often generate code which does memset + a few stores.
2. Zero initialization
Zero initialize all values. This has the unfortunate side-effect of
providing semantics to otherwise undefined behavior, programs therefore
might start to rely on this behavior, and that's sad. However, some
programmers believe that pattern initialization is too expensive for them,
and data might show that they're right. The only way to make these
programmers wrong is to offer zero-initialization as an option, figure out
where they are right, and optimize the compiler into submission. Until the
compiler provides acceptable performance for all security-minded code, zero
initialization is a useful (if blunt) tool.
I've been asked for a fourth initialization option: user-provided byte value.
This might be useful, and can easily be added later.
Why is an out-of band initialization mecanism desired? We could instead use
-Wuninitialized! Indeed we could, but then we're forcing the programmer to
provide semantics for something which doesn't actually have any (it's
uninitialized!). It's then unclear whether `int derp = 0;` lends meaning to `0`,
or whether it's just there to shut that warning up. It's also way easier to use
a compiler flag than it is to manually and intelligently initialize all values
in a program.
Why not just rely on static analysis? Because it cannot reason about all dynamic
code paths effectively, and it has false positives. It's a great tool, could get
even better, but it's simply incapable of catching all uses of uninitialized
values.
Why not just rely on memory sanitizer? Because it's not universally available,
has a 3x performance cost, and shouldn't be deployed in production. Again, it's
a great tool, it'll find the dynamic uses of uninitialized variables that your
test coverage hits, but it won't find the ones that you encounter in production.
What's the performance like? Not too bad! Previous publications [0] have cited
2.7 to 4.5% averages. We've commmitted a few patches over the last few months to
address specific regressions, both in code size and performance. In all cases,
the optimizations are generally useful, but variable initialization benefits
from them a lot more than regular code does. We've got a handful of other
optimizations in mind, but the code is in good enough shape and has found enough
latent issues that it's a good time to get the change reviewed, checked in, and
have others kick the tires. We'll continue reducing overheads as we try this out
on diverse codebases.
Is it a good idea? Security-minded folks think so, and apparently so does the
Microsoft Visual Studio team [1] who say "Between 2017 and mid 2018, this
feature would have killed 49 MSRC cases that involved uninitialized struct data
leaking across a trust boundary. It would have also mitigated a number of bugs
involving uninitialized struct data being used directly.". They seem to use pure
zero initialization, and claim to have taken the overheads down to within noise.
Don't just trust Microsoft though, here's another relevant person asking for
this [2]. It's been proposed for GCC [3] and LLVM [4] before.
What are the caveats? A few!
- Variables declared in unreachable code, and used later, aren't initialized.
This goto, Duff's device, other objectionable uses of switch. This should
instead be a hard-error in any serious codebase.
- Volatile stack variables are still weird. That's pre-existing, it's really
the language's fault and this patch keeps it weird. We should deprecate
volatile [5].
- As noted above, padding isn't fully handled yet.
I don't think these caveats make the patch untenable because they can be
addressed separately.
Should this be on by default? Maybe, in some circumstances. It's a conversation
we can have when we've tried it out sufficiently, and we're confident that we've
eliminated enough of the overheads that most codebases would want to opt-in.
Let's keep our precious undefined behavior until that point in time.
How do I use it:
1. On the command-line:
-ftrivial-auto-var-init=uninitialized (the default)
-ftrivial-auto-var-init=pattern
-ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
2. Using an attribute:
int dont_initialize_me __attribute((uninitialized));
[0]: https://users.elis.ugent.be/~jsartor/researchDocs/OOPSLA2011Zero-submit.pdf
[1]: https://twitter.com/JosephBialek/status/1062774315098112001
[2]: https://outflux.net/slides/2018/lss/danger.pdf
[3]: https://gcc.gnu.org/ml/gcc-patches/2014-06/msg00615.html
[4]: 776a0955ef
[5]: http://wg21.link/p1152
I've also posted an RFC to cfe-dev: http://lists.llvm.org/pipermail/cfe-dev/2018-November/060172.html
<rdar://problem/39131435>
Reviewers: pcc, kcc, rsmith
Subscribers: JDevlieghere, jkorous, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D54604
llvm-svn: 349442
Now that MSVC compatibility versions are stored as a four digit number
(1912) instead of a two digit number (19), we need to adjust how we
handle this attribute.
Also add a new test that was intended to be part of r349414.
llvm-svn: 349415
Summary:
The msvc exception specifier for noexcept function types has changed
from the prior default of "Z" to "_E" if the function cannot throw when
compiling with /std:C++17.
Patch by Zachary Henkel!
Reviewers: zturner, rnk
Reviewed By: rnk
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D55685
llvm-svn: 349414
This matches what GCC does in these situations.
This fixes compiling Qt in debug mode. In release mode, references to
the vtable of this particular class ends up optimized away, but in debug
mode, the compiler creates references to the vtable, which is expected
to be dllexported from a different DLL. Make sure the dllexported
version actually ends up emitted.
Differential Revision: https://reviews.llvm.org/D55698
llvm-svn: 349256
This reverts commit 46efdf2ccc2a80aefebf8433dbf9c7c959f6e629.
Richard Smith commented just after I submitted this that this is the
wrong solution. Reverting so that I can fix differently.
llvm-svn: 349206
Core issue 1013 suggests that having an uninitialied std::nullptr_t be
UB is a bit foolish, since there is only a single valid value. This DR
reports that DR616 fixes it, which does so by making lvalue-to-rvalue
conversions from nullptr_t be equal to nullptr.
However, just implementing that results in warnings/etc in many places.
In order to fix all situations where nullptr_t would seem uninitialized,
this patch instead (as an otherwise transparent extension) default
initializes uninitialized VarDecls of nullptr_t.
Differential Revision: https://reviews.llvm.org/D53713
Change-Id: I84d72a9290054fa55341e8cbdac43c8e7f25b885
llvm-svn: 349201
Summary:
This patch adds `__builtin_launder`, which is required to implement `std::launder`. Additionally GCC provides `__builtin_launder`, so thing brings Clang in-line with GCC.
I'm not exactly sure what magic `__builtin_launder` requires, but based on previous discussions this patch applies a `@llvm.invariant.group.barrier`. As noted in previous discussions, this may not be enough to correctly handle vtables.
Reviewers: rnk, majnemer, rsmith
Reviewed By: rsmith
Subscribers: kristina, Romain-Geissler-1A, erichkeane, amharc, jroelofs, cfe-commits, Prazek
Differential Revision: https://reviews.llvm.org/D40218
llvm-svn: 349195
Found the case in the clang codebase where the assertion fires.
To avoid crashing assertion-enabled builds before I re-add the missing
operation.
Will restore the assertion alongside the upcoming fix.
llvm-svn: 349061
Address spaces are cast into generic before invoking the constructor.
Added support for a trailing Qualifiers object in FunctionProtoType.
Note: This recommits the previously reverted patch,
but now it is commited together with a fix for lldb.
Differential Revision: https://reviews.llvm.org/D54862
llvm-svn: 349019
Summary:
Currently the Clang AST doesn't store information about how the callee of a CallExpr was found. Specifically if it was found using ADL.
However, this information is invaluable to tooling. Consider a tool which renames usages of a function. If the originally CallExpr was formed using ADL, then the tooling may need to additionally qualify the replacement.
Without information about how the callee was found, the tooling is left scratching it's head. Additionally, we want to be able to match ADL calls as quickly as possible, which means avoiding computing the answer on the fly.
This patch changes `CallExpr` to store whether it's callee was found using ADL. It does not change the size of any AST nodes.
Reviewers: fowles, rsmith, klimek, shafik
Reviewed By: rsmith
Subscribers: aaron.ballman, riccibruno, calabrese, titus, cfe-commits
Differential Revision: https://reviews.llvm.org/D55534
llvm-svn: 348977
Address spaces are cast into generic before invoking the constructor.
Added support for a trailing Qualifiers object in FunctionProtoType.
Differential Revision: https://reviews.llvm.org/D54862
llvm-svn: 348927
As reported in PR39946, these two implementations cause stack overflows
to occur when a type recursively contains itself. While this only
happens when an incomplete version of itself is used by membership (and
thus an otherwise invalid program), the crashes might be surprising.
The solution here is to replace the recursive implementation with one
that uses a std::vector as a queue. Old values are kept around to
prevent re-checking already checked types.
Change-Id: I582bb27147104763d7daefcfee39d91f408b9fa8
llvm-svn: 348899
Only explicitly look through integer and floating-point promotion where the result type is actually a promotion, which is not always the case for bit-fields in C.
llvm-svn: 348889
Implement support for try-catch blocks in constexpr functions, as
proposed in http://wg21.link/P1002 and voted in San Diego for c++20.
The idea is that we can still never throw inside constexpr, so the catch
block is never entered. A try-catch block like this:
try { f(); } catch (...) { }
is then morally equivalent to just
{ f(); }
Same idea should apply for function/constructor try blocks.
rdar://problem/45530773
Differential Revision: https://reviews.llvm.org/D55097
llvm-svn: 348789
Use zip_longest in two locations that compare iterator ranges.
zip_longest allows the iteration using a range-based for-loop and to be
symmetric over both ranges instead of prioritizing one over the other.
In that latter case code have to handle the case that the first is
longer than the second, the second is longer than the first, and both
are of the same length, which must partially be checked after the loop.
With zip_longest, this becomes an element comparison within the loop
like the comparison of the elements themselves. The symmetry makes it
clearer that neither the first and second iterators are handled
differently. The iterators are not event used directly anymore, just
the ranges.
Differential Revision: https://reviews.llvm.org/D55468
llvm-svn: 348762
Summary:
...that fires when running completion inside an argument of
UnresolvedMemberExpr (see the added test).
The assertion that fires is from Sema::TryObjectArgumentInitialization:
assert(FromClassification.isLValue());
This happens because Sema::AddFunctionCandidates does not account for
object types which are pointers. It ends up classifying them incorrectly.
All usages of the function outside code completion are used to run
overload resolution for operators. In those cases the object type being
passed is always a non-pointer type, so it's not surprising the function
did not expect a pointer in the object argument.
However, code completion reuses the same function and calls it with the
object argument coming from UnresolvedMemberExpr, which can be a pointer
if the member expr is an arrow ('->') access.
Extending AddFunctionCandidates to allow pointer object types does not
seem too crazy since all the functions down the call chain can properly
handle pointer object types if we properly classify the object argument
as an l-value, i.e. the classification of the implicitly dereferenced
pointer.
Reviewers: kadircet
Reviewed By: kadircet
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D55331
llvm-svn: 348590
The attribute specifies that the call of the C++ method consumes a
reference to "this".
Differential Revision: https://reviews.llvm.org/D55155
llvm-svn: 348532
Friend function template defined in a class template becomes available if
the enclosing class template is instantiated. Until the function template
is used, it does not have a body, but still is considered a definition for
the purpose of redeclaration checks.
This change modifies redefinition check so that it can find the friend
function template definitions in instantiated classes.
Differential Revision: http://reviews.llvm.org/D21508
llvm-svn: 348473
This patch adds the noderef attribute in clang and checks for dereferences of
types that have this attribute. This attribute is currently used by sparse and
would like to be ported to clang.
Differential Revision: https://reviews.llvm.org/D49511
llvm-svn: 348442
This patch creates a new context for every function definition we enter.
Currently we do not push and pop on these, usually working off of the global
context record added in the Sema constructor, which never gets popped.
Differential Revision: https://reviews.llvm.org/D54014
llvm-svn: 348434
We would issue a false-positive diagnostic for parameters in function declarations shadowing fields; we now only issue the diagnostic on a function definition instead.
llvm-svn: 348400
Added new diagnostic when templates are instantiated with
different address space from the one provided in its definition.
This also prevents deducing generic address space in pointer
type of templates to allow giving them concrete address space
during instantiation.
Differential Revision: https://reviews.llvm.org/D55127
llvm-svn: 348382
Summary:
In our codebase, `static_assert(std::some_type_trait<Ts...>::value, "msg")`
(where `some_type_trait` is an std type_trait and `Ts...` is the
appropriate template parameters) account for 11.2% of the `static_assert`s.
In these cases, the `Ts` are typically not spelled out explicitly, e.g.
`static_assert(std::is_same<SomeT::TypeT, typename SomeDependentT::value_type>::value, "message");`
The diagnostic when the assert fails is typically not very useful, e.g.
`static_assert failed due to requirement 'std::is_same<SomeT::TypeT, typename SomeDependentT::value_type>::value' "message"`
This change makes the diagnostic spell out the types explicitly , e.g.
`static_assert failed due to requirement 'std::is_same<int, float>::value' "message"`
See tests for more examples.
After this is submitted, I intend to handle
`static_assert(!std::some_type_trait<Ts...>::value, "msg")`,
which is another 6.6% of static_asserts.
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D54903
llvm-svn: 348239
When the global new and delete operators aren't declared, Clang
provides and implicit declaration, but this declaration currently
always uses the default visibility. This is a problem when the
C++ library itself is being built with non-default visibility because
the implicit declaration will force the new and delete operators to
have the default visibility unlike the rest of the library.
The existing workaround is to use assembly to enforce the visiblity:
https://fuchsia.googlesource.com/zircon/+/master/system/ulib/zxcpp/new.cpp#108
but that solution is not always available, e.g. in the case of of
libFuzzer which is using an internal version of libc++ that's also built
with -fvisibility=hidden where the existing behavior is causing issues.
This change introduces a new option -fvisibility-global-new-delete-hidden
which makes the implicit declaration of the global new and delete
operators hidden.
Differential Revision: https://reviews.llvm.org/D53787
llvm-svn: 348234
headers.
Previously, we would only check whether the new declaration is in a
system header, but that requires the user to be able to correctly guess
whether a declaration in a system header is declared as a struct or a
class when specializing standard library traits templates.
We now entirely ignore declarations for which the warning was disabled
when determining whether to warn on a tag mismatch.
Also extend the diagnostic message to clarify that
a) code containing such a tag mismatch is in fact valid and correct,
and
b) the (non-coding-style) reason to emit such a warning is that the
Microsoft C++ ABI is broken and includes the tag kind in decorated
names,
as it seems a lot of users are confused by our diagnostic here (either
not understanding why we produce it, or believing that it represents an
actual language rule).
llvm-svn: 348233
CallExpr::setNumArgs is the only thing that prevents storing the arguments
in a trailing array. There is only 3 places in Sema where setNumArgs is called.
D54900 dealt with one of them.
This patch remove the other two calls to setNumArgs in ConvertArgumentsForCall.
To do this we do the following changes:
1.) Replace the first call to setNumArgs by an assertion since we are moving the
responsability to allocate enough space for the arguments from
Sema::ConvertArgumentsForCall to its callers
(which are Sema::BuildCallToMemberFunction, and Sema::BuildResolvedCallExpr).
2.) Add a new member function CallExpr::shrinkNumArgs, which can only be used
to drop arguments and then replace the second call to setNumArgs by
shrinkNumArgs.
3.) Add a new defaulted parameter MinNumArgs to CallExpr and its derived
classes which specifies a minimum number of argument slots to allocate.
The actual number of arguments slots allocated will be
max(number of args, MinNumArgs) with the extra args nulled. Note that
after the creation of the call expression all of the arguments will be
non-null. It is just during the creation of the call expression that some of
the last arguments can be temporarily null, until filled by default arguments.
4.) Update Sema::BuildCallToMemberFunction by passing the number of parameters
in the function prototype to the constructor of CXXMemberCallExpr. Here the
change is pretty straightforward.
5.) Update Sema::BuildResolvedCallExpr. Here the change is more complicated
since the type-checking for the function type was done after the creation of
the call expression. We need to move this before the creation of the call
expression, and then pass the number of parameters in the function prototype
(if any) to the constructor of the call expression.
6.) Update the deserialization of CallExpr and its derived classes.
Differential Revision: https://reviews.llvm.org/D54902
Reviewed By: aaron.ballman
llvm-svn: 348145
CallExpr::setNumArgs is the only thing that prevents storing the arguments
of a call expression in a trailing array since it might resize the argument
array. setNumArgs is only called in 3 places in Sema, and for all of them it
is possible to avoid it.
This deals with the call to setNumArgs in BuildCallToObjectOfClassType.
Instead of constructing the CXXOperatorCallExpr first and later calling
setNumArgs if we have default arguments, we first construct a large
enough SmallVector, do the promotion/check of the arguments, and
then construct the CXXOperatorCallExpr.
Incidentally this also avoid reallocating the arguments when the
call operator has default arguments but this is not the primary goal.
Differential Revision: https://reviews.llvm.org/D54900
Reviewed By: aaron.ballman
llvm-svn: 348134
Summary:
This is a follow-up on https://reviews.llvm.org/D52879, addressing a few issues.
This:
- adds a FIXME for later improvement for specific builtins: I previously have only checked OpenCL ones and ensured tests cover those.
- fixed the CallExpr type.
Reviewers: riccibruno
Reviewed By: riccibruno
Subscribers: yaxunl, Anastasia, kristina, svenvh, cfe-commits
Differential Revision: https://reviews.llvm.org/D55136
llvm-svn: 348120
The spec is ambiguous on whether vector types are allowed to be
implicitly converted. The only legal context I think this can
be used for OpenCL is printf, where it seems necessary.
llvm-svn: 348083
It seems the two failing tests can be simply fixed after r348037
Fix 3 cases in Analysis/builtin-functions.cpp
Delete the bad CodeGen/builtin-constant-p.c for now
llvm-svn: 348053
Kept the "indirect_builtin_constant_p" test case in test/SemaCXX/constant-expression-cxx1y.cpp
while we are investigating why the following snippet fails:
extern char extern_var;
struct { int a; } a = {__builtin_constant_p(extern_var)};
llvm-svn: 348039
Richard Smith