The SVE ACLE allows using a short-form for the intrinsics, e.g.
the following two declarations generate the same code:
svuint32_t svld1(svbool_t, uint32_t const *);
svuint32_t svld1_u32(svbool_t, uint32_t const *);
using the attribute:
__clang_arm_builtin_alias
so that any call to svld1(svbool_t, uint32_t const *) will
map to __builtin_sve_svld1_u32.
Reviewers: SjoerdMeijer, miyuki, efriedma, simon_tatham, rengolin
Reviewed By: SjoerdMeijer
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75861
Summary:
[Clang] Attribute to allow defining undef global variables
Initializing global variables is very cheap on hosted implementations. The
C semantics of zero initializing globals work very well there. It is not
necessarily cheap on freestanding implementations. Where there is no loader
available, code must be emitted near the start point to write the appropriate
values into memory.
At present, external variables can be declared in C++ and definitions provided
in assembly (or IR) to achive this effect. This patch provides an attribute in
order to remove this reason for writing assembly for performance sensitive
freestanding implementations.
A close analogue in tree is LDS memory for amdgcn, where the kernel is
responsible for initializing the memory after it starts executing on the gpu.
Uninitalized variables in LDS are observably cheaper than zero initialized.
Patch is loosely based on the cuda __shared__ and opencl __local variable
implementation which also produces undef global variables.
Reviewers: kcc, rjmccall, rsmith, glider, vitalybuka, pcc, eugenis, vlad.tsyrklevich, jdoerfert, gregrodgers, jfb, aaron.ballman
Reviewed By: rjmccall, aaron.ballman
Subscribers: Anastasia, aaron.ballman, davidb, Quuxplusone, dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74361
A previous patch rejected alignof for sizeless types. This patch
extends that to cover the "aligned" attribute and _Alignas. Since
sizeless types are not meant to be used for long-term data, cannot
be used in aggregates, and cannot have static storage duration,
there shouldn't be any need to fiddle with their alignment.
Like with alignof, this is a conservative position that can be
relaxed in future if it turns out to be too restrictive.
Differential Revision: https://reviews.llvm.org/D75573
Summary:
This patch generalizes the existing code to support CDE intrinsics
which will share some properties with existing MVE intrinsics
(some of the intrinsics will be polymorphic and accept/return values
of MVE vector types).
Specifically the patch:
* Adds new tablegen backends -gen-arm-cde-builtin-def,
-gen-arm-cde-builtin-codegen, -gen-arm-cde-builtin-sema,
-gen-arm-cde-builtin-aliases, -gen-arm-cde-builtin-header based on
existing MVE backends.
* Renames the '__clang_arm_mve_alias' attribute into
'__clang_arm_builtin_alias' (it will be used with CDE intrinsics as
well as MVE intrinsics)
* Implements semantic checks for the coprocessor argument of the CDE
intrinsics as well as the existing coprocessor intrinsics.
* Adds one CDE intrinsic __arm_cx1 to test the above changes
Reviewers: simon_tatham, MarkMurrayARM, ostannard, dmgreen
Reviewed By: simon_tatham
Subscribers: sdesmalen, mgorny, kristof.beyls, danielkiss, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D75850
Reduces compile time of SemaDeclAttr.cpp down to 28s from 50s. The new
TU does a few RecursiveASTVisitor instantiations, so it takes 30s.
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D73385
There is llvm::Value::MaximumAlignment, which is numerically
equivalent to these constants, but we can't use it directly
because we can't include llvm IR headers in clang Sema.
So instead, copy-paste the constant, and fixup the places to use it.
This was initially reviewed in https://reviews.llvm.org/D72998
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.
This was initially committed in a4cfb15d15
but reverted in 210f0882c9 due to
suspicious bot failures.
Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72994
Summary:
I kind-of understand why it is restricted to integer-typed arguments,
for general enum's the value passed is not nessesairly the alignment implied,
although one might say that user would know best.
But we clearly should whitelist `std::align_val_t`,
which is just a thin wrapper over `std::size_t`,
and is the C++ standard way of specifying alignment.
Reviewers: erichkeane, rsmith, aaron.ballman, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73019
Summary:
I initially encountered those assertions when trying to create
this IR `alignment` attribute from clang's `__attribute__((assume_aligned(imm)))`,
because until D72994 there is no sanity checking for the value of `imm`.
But even then, we have `llvm::Value::MaximumAlignment` constant (which is `536870912`),
which is enforced for clang attributes, and then there are some other magical constant
(`0x40000000` i.e. `1073741824` i.e. `2 * 536870912`) in
`Attribute::getWithAlignment()`/`AttrBuilder::addAlignmentAttr()`.
I strongly suspect that `0x40000000` is incorrect,
and that also should be `llvm::Value::MaximumAlignment`.
Reviewers: erichkeane, hfinkel, jdoerfert, gchatelet, courbet
Reviewed By: erichkeane
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72998
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.
Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert
Reviewed By: erichkeane
Subscribers: cfe-commits, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D72994
This feature is generic. Make it applicable for AArch64 and X86 because
the backend has only implemented NOP insertion for AArch64 and X86.
Reviewed By: nickdesaulniers, aaron.ballman
Differential Revision: https://reviews.llvm.org/D72221
Summary:
Avoid using the `nocf_check` attribute with Control Flow Guard. Instead, use a
new `"guard_nocf"` function attribute to indicate that checks should not be
added on indirect calls within that function. Add support for
`__declspec(guard(nocf))` following the same syntax as MSVC.
Reviewers: rnk, dmajor, pcc, hans, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: aaron.ballman, tomrittervg, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D72167
Function trailing requires clauses now parsed, supported in overload resolution and when calling, referencing and taking the address of functions or function templates.
Differential Revision: https://reviews.llvm.org/D43357
It turns out it is useful to be able to define the deref type as void.
In case we have a type erased owner, we want to express that the pointee
can be basically any type. It should not be unnatural to have a void
deref type as we already familiar with "pointers to void".
Differential Revision: https://reviews.llvm.org/D72097
msvc allows a subsequent declaration of a uuid attribute on a
struct/class. Mirror this behavior in clang-cl.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D71439
These annotations will be used in an upcomming static analyzer check
that finds handle leaks, use after releases, and double releases.
Differential Revision: https://reviews.llvm.org/D70469
This change updates the clang front end to add symbols to llvm.used
when they have explicit export_name attribute.
Differential Revision: https://reviews.llvm.org/D71493
This is equivalent to the existing `import_name` and `import_module`
attributes which control the import names in the final wasm binary
produced by lld.
This maps the existing
This attribute currently requires a string rather than using the
symbol name for a couple of reasons:
1. Avoid confusion with static and dynamic linking which is
based on symbol name. Exporting a function from a wasm module using
this directive is orthogonal to both static and dynamic linking.
2. Avoids name mangling.
Differential Revision: https://reviews.llvm.org/D70520
SYCL is single source offload programming model relying on compiler to
separate device code (i.e. offloaded to an accelerator) from the code
executed on the host.
Here is code example of the SYCL program to demonstrate compiler
outlining work:
```
int foo(int x) { return ++x; }
int bar(int x) { throw std::exception("CPU code only!"); }
...
using namespace cl::sycl;
queue Q;
buffer<int, 1> a(range<1>{1024});
Q.submit([&](handler& cgh) {
auto A = a.get_access<access::mode::write>(cgh);
cgh.parallel_for<init_a>(range<1>{1024}, [=](id<1> index) {
A[index] = index[0] + foo(42);
});
}
...
```
SYCL device compiler must compile lambda expression passed to
cl::sycl::handler::parallel_for method and function foo called from this
lambda expression for an "accelerator". SYCL device compiler also must
ignore bar function as it's not required for offloaded code execution.
This patch adds the sycl_kernel attribute, which is used to mark code
passed to cl::sycl::handler::parallel_for as "accelerated code".
Attribute must be applied to function templates which parameters include
at least "kernel name" and "kernel function object". These parameters
will be used to establish an ABI between the host application and
offloaded part.
Reviewers: jlebar, keryell, Naghasan, ABataev, Anastasia, bader, aaron.ballman, rjmccall, rsmith
Reviewed By: keryell, bader
Subscribers: mgorny, OlegM, ArturGainullin, agozillon, aaron.ballman, ebevhan, Anastasia, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60455
Signed-off-by: Alexey Bader <alexey.bader@intel.com>
This avoids the need to include Attr.h in DeclCXX.h for a four-value
enum. Removing the include will be done separately, since it is large
and risky change.
__attribute__((objc_direct)) is an attribute on methods declaration, and
__attribute__((objc_direct_members)) on implementation, categories or
extensions.
A `direct` property specifier is added (@property(direct) type name)
These attributes / specifiers cause the method to have no associated
Objective-C metadata (for the property or the method itself), and the
calling convention to be a direct C function call.
The symbol for the method has enforced hidden visibility and such direct
calls are hence unreachable cross image. An explicit C function must be
made if so desired to wrap them.
The implicit `self` and `_cmd` arguments are preserved, however to
maintain compatibility with the usual `objc_msgSend` semantics,
3 fundamental precautions are taken:
1) for instance methods, `self` is nil-checked. On arm64 backends this
typically adds a single instruction (cbz x0, <closest-ret>) to the
codegen, for the vast majority of the cases when the return type is a
scalar.
2) for class methods, because the class may not be realized/initialized
yet, a call to `[self self]` is emitted. When the proper deployment
target is used, this is optimized to `objc_opt_self(self)`.
However, long term we might want to emit something better that the
optimizer can reason about. When inlining kicks in, these calls
aren't optimized away as the optimizer has no idea that a single call
is really necessary.
3) the calling convention for the `_cmd` argument is changed: the caller
leaves the second argument to the call undefined, and the selector is
loaded inside the body when it's referenced only.
As far as error reporting goes, the compiler refuses:
- making any overloads direct,
- making an overload of a direct method,
- implementations marked as direct when the declaration in the
interface isn't (the other way around is allowed, as the direct
attribute is inherited from the declaration),
- marking methods required for protocol conformance as direct,
- messaging an unqualified `id` with a direct method,
- forming any @selector() expression with only direct selectors.
As warnings:
- any inconsistency of direct-related calling convention when
@selector() or messaging is used,
- forming any @selector() expression with a possibly direct selector.
Lastly an `objc_direct_members` attribute is added that can decorate
`@implementation` blocks and causes methods only declared there (and in
no `@interface`) to be automatically direct. When decorating an
`@interface` then all methods and properties declared in this block are
marked direct.
Radar-ID: rdar://problem/2684889
Differential Revision: https://reviews.llvm.org/D69991
Reviewed-By: John McCall
This is a resubmission for the previous reverted commit
9434360401 with the same subject. This commit fixed the
segfault issue and addressed additional review comments.
This patch introduced a new bpf specific attribute which can
be added to struct or union definition. For example,
struct s { ... } __attribute__((preserve_access_index));
union u { ... } __attribute__((preserve_access_index));
The goal is to simplify user codes for cases
where preserve access index happens for certain struct/union,
so user does not need to use clang __builtin_preserve_access_index
for every members.
The attribute has no effect if -g is not specified.
When the attribute is specified and -g is specified, any member
access defined by that structure or union, including array subscript
access and inner records, will be preserved through
__builtin_preserve_{array,struct,union}_access_index()
IR intrinsics, which will enable relocation generation
in bpf backend.
The following is an example to illustrate the usage:
-bash-4.4$ cat t.c
#define __reloc__ __attribute__((preserve_access_index))
struct s1 {
int c;
} __reloc__;
struct s2 {
union {
struct s1 b[3];
};
} __reloc__;
struct s3 {
struct s2 a;
} __reloc__;
int test(struct s3 *arg) {
return arg->a.b[2].c;
}
-bash-4.4$ clang -target bpf -g -S -O2 t.c
A relocation with access string "0:0:0:0:2:0" will be generated
representing access offset of arg->a.b[2].c.
forward declaration with attribute is also handled properly such
that the attribute is copied and populated in real record definition.
Differential Revision: https://reviews.llvm.org/D69759
This patch introduced a new bpf specific attribute which can
be added to struct or union definition. For example,
struct s { ... } __attribute__((preserve_access_index));
union u { ... } __attribute__((preserve_access_index));
The goal is to simplify user codes for cases
where preserve access index happens for certain struct/union,
so user does not need to use clang __builtin_preserve_access_index
for every members.
The attribute has no effect if -g is not specified.
When the attribute is specified and -g is specified, any member
access defined by that structure or union, including array subscript
access and inner records, will be preserved through
__builtin_preserve_{array,struct,union}_access_index()
IR intrinsics, which will enable relocation generation
in bpf backend.
The following is an example to illustrate the usage:
-bash-4.4$ cat t.c
#define __reloc__ __attribute__((preserve_access_index))
struct s1 {
int c;
} __reloc__;
struct s2 {
union {
struct s1 b[3];
};
} __reloc__;
struct s3 {
struct s2 a;
} __reloc__;
int test(struct s3 *arg) {
return arg->a.b[2].c;
}
-bash-4.4$ clang -target bpf -g -S -O2 t.c
A relocation with access string "0:0:0:0:2:0" will be generated
representing access offset of arg->a.b[2].c.
forward declaration with attribute is also handled properly such
that the attribute is copied and populated in real record definition.
Differential Revision: https://reviews.llvm.org/D69759
Summary:
This is a follow up on https://reviews.llvm.org/D61634
This patch is simpler and only adds the no_builtin attribute.
Reviewers: tejohnson, courbet, theraven, t.p.northover, jdoerfert
Subscribers: mgrang, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D68028
This is a re-submit after it got reverted in https://reviews.llvm.org/rGbd8791610948 since the breakage doesn't seem to come from this patch.
Summary:
This is a follow up on https://reviews.llvm.org/D61634
This patch is simpler and only adds the no_builtin attribute.
Reviewers: tejohnson, courbet, theraven, t.p.northover, jdoerfert
Subscribers: mgrang, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D68028
This commit sets up the infrastructure for auto-generating <arm_mve.h>
and doing clang-side code generation for the builtins it relies on,
and demonstrates that it works by implementing a representative sample
of the ACLE intrinsics, more or less matching the ones introduced in
LLVM IR by D67158,D68699,D68700.
Like NEON, that header file will provide a set of vector types like
uint16x8_t and C functions with names like vaddq_u32(). Unlike NEON,
the ACLE spec for <arm_mve.h> includes a polymorphism system, so that
you can write plain vaddq() and disambiguate by the vector types you
pass to it.
Unlike the corresponding NEON code, I've arranged to make every user-
facing ACLE intrinsic into a clang builtin, and implement all the code
generation inside clang. So <arm_mve.h> itself contains nothing but
typedefs and function declarations, with the latter all using the new
`__attribute__((__clang_builtin))` system to arrange that the user-
facing function names correspond to the right internal BuiltinIDs.
So the new MveEmitter tablegen system specifies the full sequence of
IRBuilder operations that each user-facing ACLE intrinsic should
translate into. Where possible, the ACLE intrinsics map to standard IR
operations such as vector-typed `add` and `fadd`; where no standard
representation exists, I call down to the sample IR intrinsics
introduced in an earlier commit.
Doing it like this means that you get the polymorphism for free just
by using __attribute__((overloadable)): the clang overload resolution
decides which function declaration is the relevant one, and _then_ its
BuiltinID is looked up, so by the time we're doing code generation,
that's all been resolved by the standard system. It also means that
you get really nice error messages if the user passes the wrong
combination of types: clang will show the declarations from the header
file and explain why each one doesn't match.
(The obvious alternative approach would be to have wrapper functions
in <arm_mve.h> which pass their arguments to the underlying builtins.
But that doesn't work in the case where one of the arguments has to be
a constant integer: the wrapper function can't pass the constantness
through. So you'd have to do that case using a macro instead, and then
use C11 `_Generic` to handle the polymorphism. Then you have to add
horrible workarounds because `_Generic` requires even the untaken
branches to type-check successfully, and //then// if the user gets the
types wrong, the error message is totally unreadable!)
Reviewers: dmgreen, miyuki, ostannard
Subscribers: mgorny, javed.absar, kristof.beyls, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67161
This allows you to declare a function with a name of your choice (say
`foo`), but have clang treat it as if it were a builtin function (say
`__builtin_foo`), by writing
static __inline__ __attribute__((__clang_arm_mve_alias(__builtin_foo)))
int foo(args);
I'm intending to use this for the ACLE intrinsics for MVE, which have
to be polymorphic on their argument types and also need to be
implemented by builtins. To avoid having to implement the polymorphism
with several layers of nested _Generic and make error reporting
hideous, I want to make all the user-facing intrinsics correspond
directly to clang builtins, so that after clang resolves
__attribute__((overloadable)) polymorphism it's already holding the
right BuiltinID for the intrinsic it selected.
However, this commit itself just introduces the new attribute, and
doesn't use it for anything.
To avoid unanticipated side effects if this attribute is used to make
aliases to other builtins, there's a restriction mechanism: only
(BuiltinID, alias) pairs that are approved by the function
ArmMveAliasValid() will be permitted. At present, that function
doesn't permit anything, because the Tablegen that will generate its
list of valid pairs isn't yet implemented. So the only test of this
facility is one that checks that an unapproved builtin _can't_ be
aliased.
Reviewers: dmgreen, miyuki, ostannard
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D67159
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.
llvm-svn: 373753
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<RecordType> directly and if not assert will fire for us.
llvm-svn: 373584
This matches how GCC handles it, see e.g. https://gcc.godbolt.org/z/HPplnl.
GCC documents the gnu_inline attribute with "In C++, this attribute does
not depend on extern in any way, but it still requires the inline keyword
to enable its special behavior."
The previous behaviour of gnu_inline in C++, without the extern
keyword, can be traced back to the original commit that added
support for gnu_inline, SVN r69045.
Differential Revision: https://reviews.llvm.org/D67414
llvm-svn: 373078
Summary:
- Even though only `void` is still accepted as the deduced return type,
enabling deduction/instantiation on the return type allows more
consistent coding.
Reviewers: tra, jlebar
Subscribers: cfe-commits, yaxunl
Tags: #clang
Differential Revision: https://reviews.llvm.org/D68031
llvm-svn: 372898
In order to enable future improvements to our attribute diagnostics,
this moves info from ParsedAttr into CommonAttributeInfo, then makes
this type the base of the *Attr and ParsedAttr types. Quite a bit of
refactoring took place, including removing a bunch of redundant Spelling
Index propogation.
Differential Revision: https://reviews.llvm.org/D67368
llvm-svn: 371875
Reland after https://reviews.llvm.org/D66806 fixed the false-positive diagnostics.
Summary:
This fixes inference of gsl::Pointer on std::set::iterator with libstdc++ (the typedef for iterator
on the template is a DependentNameType - we can only put the gsl::Pointer attribute
on the underlaying record after instantiation)
inference of gsl::Pointer on std::vector::iterator with libc++ (the class was forward-declared,
we added the gsl::Pointer on the canonical decl (the forward decl), and later when the
template was instantiated, there was no attribute on the definition so it was not instantiated).
and a duplicate gsl::Pointer on some class with libstdc++ (we first added an attribute to
a incomplete instantiation, and then another was copied from the template definition
when the instantiation was completed).
We now add the attributes to all redeclarations to fix thos issues and make their usage easier.
Reviewers: gribozavr
Subscribers: Szelethus, xazax.hun, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66179
llvm-svn: 371182
This is mostly the same as the
[[clang::require_constant_initialization]] attribute, but has a couple
of additional syntactic and semantic restrictions.
In passing, I added a warning for the attribute form being added after
we have already seen the initialization of the variable (but before we
see the definition); that case previously slipped between the cracks and
the attribute was silently ignored.
llvm-svn: 370972
This reverts commit r369591, because it causes the formerly-reliable
-Wreturn-stack-address warning to start issuing false positives.
Testcase provided on the commit thread.
llvm-svn: 369677
Summary:
This fixes inference of gsl::Pointer on std::set::iterator with libstdc++ (the typedef for iterator
on the template is a DependentNameType - we can only put the gsl::Pointer attribute
on the underlaying record after instantiation)
inference of gsl::Pointer on std::vector::iterator with libc++ (the class was forward-declared,
we added the gsl::Pointer on the canonical decl (the forward decl), and later when the
template was instantiated, there was no attribute on the definition so it was not instantiated).
and a duplicate gsl::Pointer on some class with libstdc++ (we first added an attribute to
a incomplete instantiation, and then another was copied from the template definition
when the instantiation was completed).
We now add the attributes to all redeclarations to fix thos issues and make their usage easier.
Reviewers: gribozavr
Subscribers: Szelethus, xazax.hun, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D66179
llvm-svn: 369591
The default behavior of Clang's indirect function call checker will replace
the address of each CFI-checked function in the output file's symbol table
with the address of a jump table entry which will pass CFI checks. We refer
to this as making the jump table `canonical`. This property allows code that
was not compiled with ``-fsanitize=cfi-icall`` to take a CFI-valid address
of a function, but it comes with a couple of caveats that are especially
relevant for users of cross-DSO CFI:
- There is a performance and code size overhead associated with each
exported function, because each such function must have an associated
jump table entry, which must be emitted even in the common case where the
function is never address-taken anywhere in the program, and must be used
even for direct calls between DSOs, in addition to the PLT overhead.
- There is no good way to take a CFI-valid address of a function written in
assembly or a language not supported by Clang. The reason is that the code
generator would need to insert a jump table in order to form a CFI-valid
address for assembly functions, but there is no way in general for the
code generator to determine the language of the function. This may be
possible with LTO in the intra-DSO case, but in the cross-DSO case the only
information available is the function declaration. One possible solution
is to add a C wrapper for each assembly function, but these wrappers can
present a significant maintenance burden for heavy users of assembly in
addition to adding runtime overhead.
For these reasons, we provide the option of making the jump table non-canonical
with the flag ``-fno-sanitize-cfi-canonical-jump-tables``. When the jump
table is made non-canonical, symbol table entries point directly to the
function body. Any instances of a function's address being taken in C will
be replaced with a jump table address.
This scheme does have its own caveats, however. It does end up breaking
function address equality more aggressively than the default behavior,
especially in cross-DSO mode which normally preserves function address
equality entirely.
Furthermore, it is occasionally necessary for code not compiled with
``-fsanitize=cfi-icall`` to take a function address that is valid
for CFI. For example, this is necessary when a function's address
is taken by assembly code and then called by CFI-checking C code. The
``__attribute__((cfi_jump_table_canonical))`` attribute may be used to make
the jump table entry of a specific function canonical so that the external
code will end up taking a address for the function that will pass CFI checks.
Fixes PR41972.
Differential Revision: https://reviews.llvm.org/D65629
llvm-svn: 368495
Summary:
This is the first part of work announced in
"[RFC] Adding lifetime analysis to clang" [0],
i.e. the addition of the [[gsl::Owner(T)]] and
[[gsl::Pointer(T)]] attributes, which
will enable user-defined types to participate in
the lifetime analysis (which will be part of the
next PR).
The type `T` here is called "DerefType" in the paper,
and denotes the type that an Owner owns and a Pointer
points to. E.g. `std::vector<int>` should be annotated
with `[[gsl::Owner(int)]]` and
a `std::vector<int>::iterator` with `[[gsl::Pointer(int)]]`.
[0] http://lists.llvm.org/pipermail/cfe-dev/2018-November/060355.html
Reviewers: gribozavr
Subscribers: xazax.hun, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63954
llvm-svn: 367040
As passed in the Cologne meeting and treated by Core as a DR,
[[nodiscard]] was applied to constructors so that they can be diagnosed
in cases where the user forgets a variable name for a type.
The intent is to enable the library to start using this on the
constructors of scope_guard/lock_guard.
Differential Revision: https://reviews.llvm.org/D64914
llvm-svn: 367027
As discussed in D64780 the wording of this warning message is being
changed to say 'is not supported' instead of 'ignored', and the
diag ID itself is being changed to warn_cconv_not_supported.
llvm-svn: 366368
The CCCR_Ignore action is only used for Microsoft calling conventions,
mainly because MSVC does not warn when a calling convention would be
ignored by the current target. This behavior is actually somewhat
important, since windows.h uses WINAPI (which expands to __stdcall)
widely. This distinction didn't matter much before the introduction of
__vectorcall to x64 and the ability to make that the default calling
convention with /Gv. Now, we can't just ignore __stdcall for x64, we
have to treat it as an explicit __cdecl annotation.
Fixes PR42531
llvm-svn: 365579
This patch introduces support of hip_pinned_shadow variable for HIP.
A hip_pinned_shadow variable is a global variable with attribute hip_pinned_shadow.
It has external linkage on device side and has no initializer. It has internal
linkage on host side and has initializer or static constructor. It can be accessed
in both device code and host code.
This allows HIP runtime to implement support of HIP texture reference.
Differential Revision: https://reviews.llvm.org/D62738
llvm-svn: 364381
Summary:
Add support for the C++2a [[no_unique_address]] attribute for targets using the Itanium C++ ABI.
This depends on D63371.
Reviewers: rjmccall, aaron.ballman
Subscribers: dschuff, aheejin, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63451
llvm-svn: 363976
Summary:
this revision adds Lexing, Parsing and Basic Semantic for the consteval specifier as specified by http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1073r3.html
with this patch, the consteval specifier is treated as constexpr but can only be applied to function declaration.
Changes:
- add the consteval keyword.
- add parsing of consteval specifier for normal declarations and lambdas expressions.
- add the whether a declaration is constexpr is now represented by and enum everywhere except for variable because they can't be consteval.
- adapt diagnostic about constexpr to print constexpr or consteval depending on the case.
- add tests for basic semantic.
Reviewers: rsmith, martong, shafik
Reviewed By: rsmith
Subscribers: eraman, efriedma, rnkovacs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61790
llvm-svn: 363362
In response to https://bugs.llvm.org/show_bug.cgi?id=33235, it became
clear that the current mechanism of hacking through checks for the
exception specification of a function gets confused really quickly when
there are alternate exception specifiers.
This patch introcues EST_NoThrow, which is the equivilent of
EST_noexcept when caused by EST_noThrow. The existing implementation is
left in place to cover functions with no FunctionProtoType.
Differential Revision: https://reviews.llvm.org/D62435
llvm-svn: 362119
Swift requires certain classes to be not just initialized lazily on first
use, but actually allocated lazily using information that is only available
at runtime. This is incompatible with ObjC class initialization, or at least
not efficiently compatible, because there is no meaningful class symbol
that can be put in a class-ref variable at load time. This leaves ObjC
code unable to access such classes, which is undesirable.
objc_class_stub says that class references should be resolved by calling
a new ObjC runtime function with a pointer to a new "class stub" structure.
Non-ObjC compilers (like Swift) can simply emit this structure when ObjC
interop is required for a class that cannot be statically allocated,
then apply this attribute to the `@interface` in the generated ObjC header
for the class.
This attribute can be thought of as a generalization of the existing
`objc_runtime_visible` attribute which permits more efficient class
resolution as well as supporting the additon of categories to the class.
Subclassing these classes from ObjC is currently not allowed.
Patch by Slava Pestov!
llvm-svn: 362054
The intention is to add metadata to direct call sites of functions
marked with __declspec(allocator), which will ultimately result in some
S_HEAPALLOCSITE debug info records when emitting codeview.
This is a piece of PR38491
llvm-svn: 356964
After https://reviews.llvm.org/rL355317 we noticed that quite a decent
amount of code redeclares builtins (memcpy in particular, I believe
reduced from an MSVC header) with a calling convention specified.
This gets particularly troublesome when the user specifies a new
'default' calling convention on the command line.
When looking to add a diagnostic for this case, it was noticed that we
had 3 other diagnostics that differed only slightly. This patch ALSO
unifies those under a 'select'. Unfortunately, the order of words in
ONE of these diagnostics was reversed ("'thiscall' calling convention"
vs "calling convention 'thiscall'"), so this patch also standardizes on
the former.
Differential Revision: https://reviews.llvm.org/D59560
Change-Id: I79f99fe7c2301640755ffdd774b46eb44526bb22
llvm-svn: 356663
This reverts commit r353765. After talking with our c stdlib folks, we decided
to use the existing pass_object_size attribute to implement _FORTIFY_SOURCE
wrappers, like Bionic does (I didn't realize that pass_object_size could be used
for this purpose). Sorry for the flip/flop, and thanks to James Y. Knight for
pointing this out to me.
llvm-svn: 356103
enum SanitizerOrdinal has reached maximum capacity, this change extends the capacity to 128 sanitizer checks.
This can eventually allow us to add gcc 8's options "-fsanitize=pointer-substract" and "-fsanitize=pointer-compare".
This is a recommit of r354873 but with a fix for unqualified lookup error in lldb cmake build bot.
Fixes: https://llvm.org/PR39425
Differential Revision: https://reviews.llvm.org/D57914
llvm-svn: 355190
MSVC header files using vectorcall to differentiate overloaded functions, which
causes failure for AMDGPU target. This is because clang does not check function
calling convention based on function target.
This patch checks calling convention using the proper target info.
Differential Revision: https://reviews.llvm.org/D57716
llvm-svn: 354929
enum SanitizerOrdinal has reached maximum capacity, this change extends the capacity to 128 sanitizer checks.
This can eventually allow us to add gcc 8's options "-fsanitize=pointer-substract" and "-fsanitize=pointer-compare".
Fixes: https://llvm.org/PR39425
Differential Revision: https://reviews.llvm.org/D57914
llvm-svn: 354873
The new __attribute__ ((mig_server_routine)) is going to be used for annotating
Mach Interface Generator (MIG) callback functions as such, so that additional
static analysis could be applied to their implementations. It can also be
applied to regular functions behavior of which is supposed to be identical to
that of a MIG server routine.
Differential Revision: https://reviews.llvm.org/D58365
llvm-svn: 354530
This fixes a regression that was caused by r335084, which reversed
the order that attributes are applied. objc_method_family can change
whether a method is an init method, so the order that these
attributes are applied matters. The commit fixes this by delaying the
init check until after all attributes have been applied.
rdar://47829358
Differential revision: https://reviews.llvm.org/D58152
llvm-svn: 353976
This attribute applies to declarations of C stdlib functions
(sprintf, memcpy...) that have known fortified variants
(__sprintf_chk, __memcpy_chk, ...). When applied, clang will emit
calls to the fortified variant functions instead of calls to the
defaults.
In GCC, this is done by adding gnu_inline-style wrapper functions,
but that doesn't work for us for variadic functions because we don't
support __builtin_va_arg_pack (and have no intention to).
This attribute takes two arguments, the first is 'type' argument
passed through to __builtin_object_size, and the second is a flag
argument that gets passed through to the variadic checking variants.
rdar://47905754
Differential revision: https://reviews.llvm.org/D57918
llvm-svn: 353765
A non-lazy class will be initialized eagerly when the Objective-C runtime is
loaded. This is required for certain system classes which have instances allocated in
non-standard ways, such as the classes for blocks and constant strings.
Adding this attribute is essentially equivalent to providing a trivial
+load method but avoids the (fairly small) load-time overheads associated
with defining and calling such a method.
Differential Revision: https://reviews.llvm.org/D56555
llvm-svn: 353116
This is similar to import_module, but sets the import field name
instead.
By default, the import field name is the same as the C/asm/.o symbol
name. However, there are situations where it's useful to have it be
different. For example, suppose I have a wasm API with a module named
"pwsix" and a field named "read". There's no risk of namespace
collisions with user code at the wasm level because the generic name
"read" is qualified by the module name "pwsix". However in the C/asm/.o
namespaces, the module name is not used, so if I have a global function
named "read", it is intruding on the user's namespace.
With the import_field module, I can declare my function (in libc) to be
"__read", and then set the wasm import module to be "pwsix" and the wasm
import field to be "read". So at the C/asm/.o levels, my symbol is
outside the user namespace.
Differential Revision: https://reviews.llvm.org/D57602
llvm-svn: 352930
This adds a C/C++ attribute which corresponds to the LLVM IR wasm-import-module
attribute. It allows code to specify an explicit import module.
Differential Revision: https://reviews.llvm.org/D57160
llvm-svn: 352106
attributes from declaration over attributes from '#pragma clang attribute'
Before this commit users had an issue when using #pragma clang attribute with
availability attributes:
The explicit attribute that's specified next to the declaration is not
guaranteed to be preferred over the attribute specified in the pragma.
This commit fixes this by introducing a priority field to the availability
attribute to control how they're merged. Attributes with higher priority are
applied over attributes with lower priority for the same platform. The
implicitly inferred attributes are given the lower priority. This ensures that:
- explicit attributes are preferred over all other attributes.
- implicitly inferred attributes that are inferred from an explicit attribute
are discarded if there's an explicit attribute or an attribute specified
using a #pragma for the same platform.
- implicitly inferred attributes that are inferred from an attribute in the
#pragma are not used if there's an explicit, explicit #pragma, or an
implicit attribute inferred from an explicit attribute for the declaration.
This is the resulting ranking:
`platform availability > platform availability from pragma > inferred availability > inferred availability from pragma`
rdar://46390243
Differential Revision: https://reviews.llvm.org/D56892
llvm-svn: 352084
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
With commit r351627, LLVM gained the ability to apply (existing) IPO
optimizations on indirections through callbacks, or transitive calls.
The general idea is that we use an abstraction to hide the middle man
and represent the callback call in the context of the initial caller.
It is described in more detail in the commit message of the LLVM patch
r351627, the llvm::AbstractCallSite class description, and the
language reference section on callback-metadata.
This commit enables clang to emit !callback metadata that is
understood by LLVM. It does so in three different cases:
1) For known broker functions declarations that are directly
generated, e.g., __kmpc_fork_call for the OpenMP pragma parallel.
2) For known broker functions that are identified by their name and
source location through the builtin detection, e.g.,
pthread_create from the POSIX thread API.
3) For user annotated functions that carry the "callback(callee, ...)"
attribute. The attribute has to include the name, or index, of
the callback callee and how the passed arguments can be
identified (as many as the callback callee has). See the callback
attribute documentation for detailed information.
Differential Revision: https://reviews.llvm.org/D55483
llvm-svn: 351629
Summary:
This attribute will allow users to opt specific functions out of
speculative load hardening. This compliments the Clang attribute
named speculative_load_hardening. When this attribute or the attribute
speculative_load_hardening is used in combination with the flags
-mno-speculative-load-hardening or -mspeculative-load-hardening,
the function level attribute will override the default during LLVM IR
generation. For example, in the case, where the flag opposes the
function attribute, the function attribute will take precendence.
The sticky inlining behavior of the speculative_load_hardening attribute
may cause a function with the no_speculative_load_hardening attribute
to be tagged with the speculative_load_hardening tag in
subsequent compiler phases which is desired behavior since the
speculative_load_hardening LLVM attribute is designed to be maximally
conservative.
If both attributes are specified for a function, then an error will be
thrown.
Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54909
llvm-svn: 351565
declared in a parent class from within the @implementation context
This commit extends r350768 and allows the use of methods marked as unavailable
that are declared in a parent class/category from within the @implementation of
the class where the method is marked as unavailable.
This allows users to call init that's marked as unavailable even if they don't
define it.
rdar://47134898
Differential Revision: https://reviews.llvm.org/D56816
llvm-svn: 351459
* Accept as an argument constants in range 0..63 (aligned with TI headers and linker scripts provided with TI GCC toolchain).
* Emit function attribute 'interrupt'='xx' instead of aliases (used in the backend to create a section for particular interrupt vector).
* Add more diagnostics.
Patch by Kristina Bessonova!
Differential Revision: https://reviews.llvm.org/D56663
llvm-svn: 351344
Mention the deployment target, and don't say "partial" which doesn't
really mean anything to users.
rdar://problem/33601513
Differential revision: https://reviews.llvm.org/D56523
llvm-svn: 351108
When applied to out-parameters, the attributes specify the expected lifetime of the written-into object.
Additionally, introduce OSReturnsRetainedOn(Non)Zero attributes, which
specify that an ownership transfer happens depending on a return code.
Differential Revision: https://reviews.llvm.org/D56292
llvm-svn: 350942
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
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
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
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
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
The addition adds three attributes for communicating ownership,
analogous to existing NS_ and CF_ attributes.
The attributes are meant to be used for communicating ownership of all
objects in XNU (Darwin kernel) and all of the kernel modules.
The ownership model there is very similar, but still different from the
Foundation model, so we think that introducing a new family of
attributes is appropriate.
The addition required a sizeable refactoring of the existing code for
CF_ and NS_ ownership attributes, due to tight coupling and the fact
that differentiating between the types was previously done using a
boolean.
Differential Revision: https://reviews.llvm.org/D54912
llvm-svn: 347947
Summary:
Resubmit this with no changes because I think the build was broken
by a different diff.
-----
The prior diff had to be reverted because there were two tests
that failed. I updated the two tests in this diff
clang/test/Misc/pragma-attribute-supported-attributes-list.test
clang/test/SemaCXX/attr-speculative-load-hardening.cpp
----- Summary from Previous Diff (Still Accurate) -----
LLVM IR already has an attribute for speculative_load_hardening. Before
this commit, when a user passed the -mspeculative-load-hardening flag to
Clang, every function would have this attribute added to it. This Clang
attribute will allow users to opt into SLH on a function by function basis.
This can be applied to functions and Objective C methods.
Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54915
llvm-svn: 347701
until I figure out why the build is failing or timing out
***************************
Summary:
The prior diff had to be reverted because there were two tests
that failed. I updated the two tests in this diff
clang/test/Misc/pragma-attribute-supported-attributes-list.test
clang/test/SemaCXX/attr-speculative-load-hardening.cpp
LLVM IR already has an attribute for speculative_load_hardening. Before
this commit, when a user passed the -mspeculative-load-hardening flag to
Clang, every function would have this attribute added to it. This Clang
attribute will allow users to opt into SLH on a function by function
basis.
This can be applied to functions and Objective C methods.
Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54915
This reverts commit a5b3c232d1e3613f23efbc3960f8e23ea70f2a79.
(r347617)
llvm-svn: 347628
Summary:
The prior diff had to be reverted because there were two tests
that failed. I updated the two tests in this diff
clang/test/Misc/pragma-attribute-supported-attributes-list.test
clang/test/SemaCXX/attr-speculative-load-hardening.cpp
----- Summary from Previous Diff (Still Accurate) -----
LLVM IR already has an attribute for speculative_load_hardening. Before
this commit, when a user passed the -mspeculative-load-hardening flag to
Clang, every function would have this attribute added to it. This Clang
attribute will allow users to opt into SLH on a function by function basis.
This can be applied to functions and Objective C methods.
Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54915
llvm-svn: 347617
Summary:
LLVM IR already has an attribute for speculative_load_hardening. Before
this commit, when a user passed the -mspeculative-load-hardening flag to
Clang, every function would have this attribute added to it. This Clang
attribute will allow users to opt into SLH on a function by function basis.
This can be applied to functions and Objective C methods.
Reviewers: chandlerc, echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54555
llvm-svn: 347586
Summary: This adds support for Swift platform availability attributes. It's largely a port of the changes made to https://github.com/apple/swift-clang/ for Swift availability attributes. Specifically, 84b5a21c31 and e5b87f265a . The implementation of attribute_availability_swift is a little different and additional tests in test/Index/availability.c were added.
Reviewers: manmanren, friss, doug.gregor, arphaman, jfb, erik.pilkington, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: aaron.ballman, ColinKinloch, jrmuizel, cfe-commits
Differential Revision: https://reviews.llvm.org/D50318
llvm-svn: 346633
We haven't supported compiling ObjC1 for a long time (and never will again), so
there isn't any reason to keep these separate. This patch replaces
LangOpts::ObjC1 and LangOpts::ObjC2 with LangOpts::ObjC.
Differential revision: https://reviews.llvm.org/D53547
llvm-svn: 345637
Summary:
This attribute allows excluding a member of a class template from being part
of an explicit template instantiation of that class template. This also makes
sure that code using such a member will not take for granted that an external
instantiation exists in another translation unit. The attribute was discussed
on cfe-dev at [1] and is primarily motivated by the removal of always_inline
in libc++ to control what's part of the ABI (see links in [1]).
[1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html
rdar://problem/43428125
Reviewers: rsmith
Subscribers: dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D51789
llvm-svn: 343790
This patch renames -f{no-}cuda-rdc to -f{no-}gpu-rdc and keeps the original
options as aliases. When -fgpu-rdc is off,
clang will assume the device code in each translation unit does not call
external functions except those in the device library, therefore it is possible
to compile the device code in each translation unit to self-contained kernels
and embed them in the host object, so that the host object behaves like
usual host object which can be linked by lld.
The benefits of this feature is: 1. allow users to create static libraries which
can be linked by host linker; 2. amortized device code linking time.
This patch modifies HIP action builder to insert actions for linking device
code and generating HIP fatbin, and pass HIP fatbin to host backend action.
It extracts code for constructing command for generating HIP fatbin as
a function so that it can be reused by early finalization. It also modifies
codegen of HIP host constructor functions to embed the device fatbin
when it is available.
Differential Revision: https://reviews.llvm.org/D52377
llvm-svn: 343611
Objects are determined to be smart pointers if they have both a star and arrow
operator. Some implementations of smart pointers have these overloaded
operators in a base class, while the check only searched the derived class.
This fix will also look for the operators in the base class.
llvm-svn: 342794
Summary:
When thread safety annotations are used without capability arguments,
they are assumed to apply to `this` instead. So we warn when either
`this` doesn't exist, or the class is not a capability type.
This is based on earlier work by Josh Gao that was committed in r310403,
but reverted in r310698 because it didn't properly work in template
classes. See also D36237.
The solution is not to go via the QualType of `this`, which is then a
template type, hence the attributes are not known because it could be
specialized. Instead we look directly at the class in which we are
contained.
Additionally I grouped two of the warnings together. There are two
issues here: the existence of `this`, which requires us to be a
non-static member function, and the appropriate annotation on the class
we are contained in. So we don't distinguish between not being in a
class and being static, because in both cases we don't have `this`.
Fixes PR38399.
Reviewers: aaron.ballman, delesley, jmgao, rtrieu
Reviewed By: delesley
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D51901
llvm-svn: 342605
Summary:
Merged the recently added `err_attribute_argument_negative` diagnostic
with existing `err_attribute_requires_positive_integer` diagnostic:
the former allows only strictly positive integer, while the latter
also allows zero.
Reviewers: aaron.ballman
Reviewed By: aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D51853
llvm-svn: 342367
When defined in NSObject, +new will call -init. If -init has been marked
unavailable, diagnose uses of +new.
rdar://18335828
Differential revision: https://reviews.llvm.org/D51189
llvm-svn: 341874
Summary:
Negative arguments in kernel attributes are silently bitcast'ed to
unsigned, for example:
__attribute__((reqd_work_group_size(1, -1, 1)))
__kernel void k() {}
is a complete equivalent of:
__attribute__((reqd_work_group_size(1, 4294967294, 1)))
__kernel void k() {}
This is likely an error, so the patch forbids negative arguments in
several OpenCL attributes. Users who really want 4294967294 can still
use it as an unsigned representation.
Reviewers: Anastasia, yaxunl, bader
Reviewed By: Anastasia, yaxunl, bader
Subscribers: bader, cfe-commits
Differential Revision: https://reviews.llvm.org/D50259
llvm-svn: 341539
This commit adds the flag -fno-c++-static-destructors and the attributes
[[clang::no_destroy]] and [[clang::always_destroy]]. no_destroy specifies that a
specific static or thread duration variable shouldn't have it's destructor
registered, and is the default in -fno-c++-static-destructors mode.
always_destroy is the opposite, and is the default in -fc++-static-destructors
mode.
A variable whose destructor is disabled (either because of
-fno-c++-static-destructors or [[clang::no_destroy]]) doesn't count as a use of
the destructor, so we don't do any access checking or mark it referenced. We
also don't emit -Wexit-time-destructors for these variables.
rdar://21734598
Differential revision: https://reviews.llvm.org/D50994
llvm-svn: 340306
Summary:
This is for use by clang-tidy's bugprone-use-after-move check -- see
corresponding clang-tidy patch at https://reviews.llvm.org/D49910.
Reviewers: aaron.ballman, rsmith
Reviewed By: aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D49911
llvm-svn: 339569
As a part of attempting to clean up the way attributes are
printed, this patch adds an operator << to the diagnostics/
partialdiagnostics so that ParsedAttr can be sent directly.
This patch also rewrites a large amount* of the times when
ParsedAttr was printed using its IdentifierInfo object instead
of being printed itself.
*"a large amount" == "All I could find".
llvm-svn: 339344
This patch adds support for a new attribute, [[clang::lifetimebound]], that
indicates that the lifetime of a function result is related to one of the
function arguments. When walking an initializer to make sure that the lifetime
of the initial value is at least as long as the lifetime of the initialized
object, we step through parameters (including the implicit object parameter of
a non-static member function) that are marked with this attribute.
There's nowhere to write an attribute on the implicit object parameter, so in
lieu of that, it may be applied to a function type (where it appears
immediately after the cv-qualifiers and ref-qualifier, which is as close to a
declaration of the implicit object parameter as we have). I'm currently
modeling this in the AST as the attribute appertaining to the function type.
Differential Revision: https://reviews.llvm.org/D49922
llvm-svn: 338464
Summary:
Clang supports the GNU style ``__attribute__((interrupt))`` attribute on RISCV targets.
Permissible values for this parameter are user, supervisor, and machine.
If there is no parameter, then it defaults to machine.
Reference: https://gcc.gnu.org/onlinedocs/gcc/RISC-V-Function-Attributes.html
Based on initial patch by Zhaoshi Zheng.
Reviewers: asb, aaron.ballman
Reviewed By: asb, aaron.ballman
Subscribers: rkruppe, the_o, aaron.ballman, MartinMosbeck, brucehoult, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, cfe-commits
Differential Revision: https://reviews.llvm.org/D48412
llvm-svn: 338045
As documented here: https://software.intel.com/en-us/node/682969 and
https://software.intel.com/en-us/node/523346. cpu_dispatch multiversioning
is an ICC feature that provides for function multiversioning.
This feature is implemented with two attributes: First, cpu_specific,
which specifies the individual function versions. Second, cpu_dispatch,
which specifies the location of the resolver function and the list of
resolvable functions.
This is valuable since it provides a mechanism where the resolver's TU
can be specified in one location, and the individual implementions
each in their own translation units.
The goal of this patch is to be source-compatible with ICC, so this
implementation diverges from the ICC implementation in a few ways:
1- Linux x86/64 only: This implementation uses ifuncs in order to
properly dispatch functions. This is is a valuable performance benefit
over the ICC implementation. A future patch will be provided to enable
this feature on Windows, but it will obviously more closely fit ICC's
implementation.
2- CPU Identification functions: ICC uses a set of custom functions to identify
the feature list of the host processor. This patch uses the cpu_supports
functionality in order to better align with 'target' multiversioning.
1- cpu_dispatch function def/decl: ICC's cpu_dispatch requires that the function
marked cpu_dispatch be an empty definition. This patch supports that as well,
however declarations are also permitted, since the linker will solve the
issue of multiple emissions.
Differential Revision: https://reviews.llvm.org/D47474
llvm-svn: 337552
This patch uses CodeSegAttr to represent __declspec(code_seg) rather than
building on the existing support for #pragma code_seg.
The code_seg declspec is applied on functions and classes. This attribute
enables the placement of code into separate named segments, including compiler-
generated codes and template instantiations.
For more information, please see the following:
https://msdn.microsoft.com/en-us/library/dn636922.aspx
This patch fixes the regression for the support for attribute ((section).
746b78de78
Patch by Soumi Manna (Manna)
Differential Revision: https://reviews.llvm.org/D48841
llvm-svn: 337420
Basically, "AttributeList" loses all list-like mechanisms, ParsedAttributes is
switched to use a TinyPtrVector (and a ParsedAttributesView is created to
have a non-allocating attributes list). DeclaratorChunk gets the later kind,
Declarator/DeclSpec keep ParsedAttributes.
Iterators are added to the ParsedAttribute types so that for-loops work.
llvm-svn: 336945
This is part of an ongoing attempt at making 512 bit vectors illegal in the X86 backend type legalizer due to CPU frequency penalties associated with wide vectors on Skylake Server CPUs. We want the loop vectorizer to be able to emit IR containing wide vectors as intermediate operations in vectorized code and allow these wide vectors to be legalized to 256 bits by the X86 backend even though we are targetting a CPU that supports 512 bit vectors. This is similar to what happens with an AVX2 CPU, the vectorizer can emit wide vectors and the backend will split them. We want this splitting behavior, but still be able to use new Skylake instructions that work on 256-bit vectors and support things like masking and gather/scatter.
Of course if the user uses explicit vector code in their source code we need to not split those operations. Especially if they have used any of the 512-bit vector intrinsics from immintrin.h. And we need to make it so that merely using the intrinsics produces the expected code in order to be backwards compatible.
To support this goal, this patch adds a new IR function attribute "min-legal-vector-width" that can indicate the need for a minimum vector width to be legal in the backend. We need to ensure this attribute is set to the largest vector width needed by any intrinsics from immintrin.h that the function uses. The inliner will be reponsible for merging this attribute when a function is inlined. We may also need a way to limit inlining in the future as well, but we can discuss that in the future.
To make things more complicated, there are two different ways intrinsics are implemented in immintrin.h. Either as an always_inline function containing calls to builtins(can be target specific or target independent) or vector extension code. Or as a macro wrapper around a taget specific builtin. I believe I've removed all cases where the macro was around a target independent builtin.
To support the always_inline function case this patch adds attribute((min_vector_width(128))) that can be used to tag these functions with their vector width. All x86 intrinsic functions that operate on vectors have been tagged with this attribute.
To support the macro case, all x86 specific builtins have also been tagged with the vector width that they require. Use of any builtin with this property will implicitly increase the min_vector_width of the function that calls it. I've done this as a new property in the attribute string for the builtin rather than basing it on the type string so that we can opt into it on a per builtin basis and avoid any impact to target independent builtins.
There will be future work to support vectors passed as function arguments and supporting inline assembly. And whatever else we can find that isn't covered by this patch.
Special thanks to Chandler who suggested this direction and reviewed a preview version of this patch. And thanks to Eric Christopher who has had many conversations with me about this issue.
Differential Revision: https://reviews.llvm.org/D48617
llvm-svn: 336583
There are HIP applications e.g. Tensorflow 1.3 using amdgpu kernel attributes, however
currently they are only allowed on OpenCL kernel functions.
This patch will allow amdgpu kernel attributes to be applied to CUDA/HIP __global__
functions.
Differential Revision: https://reviews.llvm.org/D47958
llvm-svn: 334561
Add support for __declspec(code_seg("segname"))
This patch is built on the existing support for #pragma code_seg. The code_seg
declspec is allowed on functions and classes. The attribute enables the
placement of code into separate named segments, including compiler-generated
members and template instantiations.
For more information, please see the following:
https://msdn.microsoft.com/en-us/library/dn636922.aspx
A new CodeSeg attribute is used instead of adding a new spelling to the existing
Section attribute since they don’t apply to the same Subjects. Section
attributes are also added for the code_seg declspec since they are used for
#pragma code_seg. No CodeSeg attributes are added to the AST.
The patch is written to match with the Microsoft compiler’s behavior even where
that behavior is a little complicated (see https://reviews.llvm.org/D22931, the
Microsoft feedback page is no longer available since MS has removed the page).
That code is in getImplicitSectionAttrFromClass routine.
Diagnostics messages are added to match with the Microsoft compiler for code-seg
attribute mismatches on base and derived classes and virtual overrides.
Differential Revision: https://reviews.llvm.org/D43352
llvm-svn: 332470
Summary:
This attribute tells clang to skip this function from stack protector
when -stack-protector option is passed.
GCC option for this is:
__attribute__((__optimize__("no-stack-protector"))) and the
equivalent clang syntax would be: __attribute__((no_stack_protector))
This is used in Linux kernel to selectively disable stack protector
in certain functions.
Reviewers: aaron.ballman, rsmith, rnk, probinson
Reviewed By: aaron.ballman
Subscribers: probinson, srhines, cfe-commits
Differential Revision: https://reviews.llvm.org/D46300
llvm-svn: 331925
This is similar to the LLVM change https://reviews.llvm.org/D46290.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46320
llvm-svn: 331834
When a '>>' token is split into two '>' tokens (in C++11 onwards), or (as an
extension) when we do the same for other tokens starting with a '>', we can't
just use a location pointing to the first '>' as the location of the split
token, because that would result in our miscomputing the length and spelling
for the token. As a consequence, for example, a refactoring replacing 'A<X>'
with something else would sometimes replace one character too many, and
similarly diagnostics highlighting a template-id source range would highlight
one character too many.
Fix this by creating an expansion range covering the first character of the
'>>' token, whose spelling is '>'. For this to work, we generalize the
expansion range of a macro FileID to be either a token range (the common case)
or a character range (used in this new case).
llvm-svn: 331155
Summary:
There are some functions/methods that run when the application launches
or the library loads. Those functions will run reguardless the OS
version as long as it satifies the minimum deployment target. Annotate
them with availability attributes doesn't really make sense because they
are essentially available on all targets since minimum deployment
target.
rdar://problem/36093384
Reviewers: arphaman, erik.pilkington
Reviewed By: erik.pilkington
Subscribers: erik.pilkington, cfe-commits
Differential Revision: https://reviews.llvm.org/D45699
llvm-svn: 330166
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:
archtype
cas
classs
checkk
compres
definit
frome
iff
inteval
ith
lod
methode
nd
optin
ot
pres
statics
te
thru
Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)
Differential revision: https://reviews.llvm.org/D44188
llvm-svn: 329399
Deprecation replacement can be any text but if it looks like a name of
ObjC method and has the same number of arguments as original method,
replace all slot names so after applying a fix-it you have valid code.
rdar://problem/36660853
Reviewers: aaron.ballman, erik.pilkington, rsmith
Reviewed By: erik.pilkington
Subscribers: cfe-commits, jkorous-apple
Differential Revision: https://reviews.llvm.org/D44589
llvm-svn: 328807
r327219 added wrappers to std::sort which randomly shuffle the container before
sorting. This will help in uncovering non-determinism caused due to undefined
sorting order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of
std::sort.
llvm-svn: 328636
The patch adds nocf_check target independent attribute for disabling checks that were enabled by cf-protection flag.
The attribute can be appertained to functions and function pointers.
Attribute name follows GCC's similar attribute name.
Differential Revision: https://reviews.llvm.org/D41880
llvm-svn: 327768
Summary:
This provides no measurable build speedup, but it reinstates an
optimization from r112038 that was lost in r179618. It requires moving
CapturedScopeInfo::Capture out to clang::sema, which might be too
general since we have plenty of other Capture records in BlockDecl and
other AST nodes.
Reviewers: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D44221
llvm-svn: 326957
These attributes were only customized because of the need to check for attribute mutual exclusion, but we now have the handleSimpleAttributeWithExclusions() helper function to handle these scenarios.
llvm-svn: 326675
The patch fixes a number of bugs related to parameter indexing in
attributes:
* Parameter indices in some attributes (argument_with_type_tag,
pointer_with_type_tag, nonnull, ownership_takes, ownership_holds,
and ownership_returns) are specified in source as one-origin
including any C++ implicit this parameter, were stored as
zero-origin excluding any this parameter, and were erroneously
printing (-ast-print) and confusingly dumping (-ast-dump) as the
stored values.
* For alloc_size, the C++ implicit this parameter was not subtracted
correctly in Sema, leading to assert failures or to silent failures
of __builtin_object_size to compute a value.
* For argument_with_type_tag, pointer_with_type_tag, and
ownership_returns, the C++ implicit this parameter was not added
back to parameter indices in some diagnostics.
This patch fixes the above bugs and aims to prevent similar bugs in
the future by introducing careful mechanisms for handling parameter
indices in attributes. ParamIdx stores a parameter index and is
designed to hide the stored encoding while providing accessors that
require each use (such as printing) to make explicit the encoding that
is needed. Attribute declarations declare parameter index arguments
as [Variadic]ParamIdxArgument, which are exposed as ParamIdx[*]. This
patch rewrites all attribute arguments that are processed by
checkFunctionOrMethodParameterIndex in SemaDeclAttr.cpp to be declared
as [Variadic]ParamIdxArgument. The only exception is xray_log_args's
argument, which is encoded as a count not an index.
Differential Revision: https://reviews.llvm.org/D43248
llvm-svn: 326602
So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.
Because of the volume of changes, I explicitly avoided making any change
that wasn't highly local and obviously correct to me (e.g. we still have
a number of foo(cast<Bar>(baz)) that I didn't touch, since overloading
is a thing and the cast<Bar> did actually change the type -- just up the
class hierarchy).
I also tried to leave the types we were cast<>ing to somewhere nearby,
in cases where it wasn't locally obvious what we were dealing with
before.
llvm-svn: 326416
The TypeTagForDatatype attribute had custom parsing rules that previously prevented it from being supported with square bracket notation. The ArgumentWithTypeTag attribute previously had unnecessary custom parsing that could be handled declaratively.
llvm-svn: 326052
There were a few issues previously with the target
attribute diagnostics implementation that lead to the
attribute being added to the AST despite having an error
in it.
This patch changes that, and adds a test to ensure it
does not get added to the AST.
Differential Revision: https://reviews.llvm.org/D43359
llvm-svn: 325364
Changed identifier names (especially function parameters) to not clash with type names and to follow the proper naming conventions. Use of explicit type names changed to use auto where appropriate. Removed unused parameters that should have never been added in the first place. Minor formatting cleanups.
The changes were mostly mechanical and should have no functional impact.
llvm-svn: 325256
According to the CUDA Programming Guide this is prohibited in
whole program compilation mode. This makes sense because external
references cannot be satisfied in that mode anyway. However,
such variables are allowed in separate compilation mode which
is a valid use case.
Differential Revision: https://reviews.llvm.org/D42923
llvm-svn: 325136
Added support in clang for GCC function attribute 'artificial'. This attribute
is used to control stepping behavior of debugger with respect to inline
functions.
Patch By: Elizabeth Andrews (eandrews)
Differential Revision: https://reviews.llvm.org/D43259
llvm-svn: 325081
The 'trivial_abi' attribute can be applied to a C++ class, struct, or
union. It makes special functions of the annotated class (the destructor
and copy/move constructors) to be trivial for the purpose of calls and,
as a result, enables the annotated class or containing classes to be
passed or returned using the C ABI for the underlying type.
When a type that is considered trivial for the purpose of calls despite
having a non-trivial destructor (which happens only when the class type
or one of its subobjects is a 'trivial_abi' class) is passed to a
function, the callee is responsible for destroying the object.
For more background, see the discussions that took place on the mailing
list:
http://lists.llvm.org/pipermail/cfe-dev/2017-November/055955.htmlhttp://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20180101/thread.html#214043
rdar://problem/35204524
Differential Revision: https://reviews.llvm.org/D41039
llvm-svn: 324269
Looking through the code, I saw a FIXME on IFunc to switch it
to a target specific attribute. In looking through it, i saw that
the no-longer-appropriately-named TargetArch didn't support ObjectFormat
checking.
This patch changes the name of TargetArch to TargetSpecific
(since it checks much more than just Arch), makes "Arch" optional, adds
support for ObjectFormat, better documents the TargetSpecific type, and
changes IFunc over to a TargetSpecificAttr.
Differential Revision: https://reviews.llvm.org/D41303
llvm-svn: 321201
There are many more expr types that can be a capability expr, like
CXXThisExpr, CallExpr, MemberExpr. Instead of enumerating all of them,
just check typeHasCapability for any type given.
Also add & and * operators to allowed unary operators.
Differential Revision: https://reviews.llvm.org/D41224
llvm-svn: 320753
Summary:
Convert clang::LangAS to a strongly typed enum
Currently both clang AST address spaces and target specific address spaces
are represented as unsigned which can lead to subtle errors if the wrong
type is passed. It is especially confusing in the CodeGen files as it is
not possible to see what kind of address space should be passed to a
function without looking at the implementation.
I originally made this change for our LLVM fork for the CHERI architecture
where we make extensive use of address spaces to differentiate between
capabilities and pointers. When merging the upstream changes I usually
run into some test failures or runtime crashes because the wrong kind of
address space is passed to a function. By converting the LangAS enum to a
C++11 we can catch these errors at compile time. Additionally, it is now
obvious from the function signature which kind of address space it expects.
I found the following errors while writing this patch:
- ItaniumRecordLayoutBuilder::LayoutField was passing a clang AST address
space to TargetInfo::getPointer{Width,Align}()
- TypePrinter::printAttributedAfter() prints the numeric value of the
clang AST address space instead of the target address space.
However, this code is not used so I kept the current behaviour
- initializeForBlockHeader() in CGBlocks.cpp was passing
LangAS::opencl_generic to TargetInfo::getPointer{Width,Align}()
- CodeGenFunction::EmitBlockLiteral() was passing a AST address space to
TargetInfo::getPointerWidth()
- CGOpenMPRuntimeNVPTX::translateParameter() passed a target address space
to Qualifiers::addAddressSpace()
- CGOpenMPRuntimeNVPTX::getParameterAddress() was using
llvm::Type::getPointerTo() with a AST address space
- clang_getAddressSpace() returns either a LangAS or a target address
space. As this is exposed to C I have kept the current behaviour and
added a comment stating that it is probably not correct.
Other than this the patch should not cause any functional changes.
Reviewers: yaxunl, pcc, bader
Reviewed By: yaxunl, bader
Subscribers: jlebar, jholewinski, nhaehnle, Anastasia, cfe-commits
Differential Revision: https://reviews.llvm.org/D38816
llvm-svn: 315871
This reverts r314461.
It is warning on user code that uses END_COM_MAP(), which expands to
declare QueryInterface with conflicting exception specifers. I've spent
a while trying to understand why, but haven't been able to extract a
reduced test case. Let's revert and I'll keep trying.
llvm-svn: 314689
I discovered it was possible to create a 'nothrow' noexcept(false)
function, which is both non-sensical as well as seemingly breaking.
This patch warns if attribute nothrow is used with anything besides "noexcept".
"noexcept(true)" isn't possible, because the noexcept decl isn't parsed until
later.
Differential Revision: https://reviews.llvm.org/D38205
llvm-svn: 314461
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.
This recommits r313722, which was reverted in r313725 because clang
couldn't build compiler-rt. It failed to build because there were
function declarations that were missing 'noescape'. That has been fixed
in r313929.
rdar://problem/19886775
Differential Revision: https://reviews.llvm.org/D32210
llvm-svn: 313945
This reverts commit r313722.
It looks like compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc cannot be
compiled because some of the functions declared in the file do not match
the ones in the SDK headers (which are annotated with 'noescape').
llvm-svn: 313725
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.
rdar://problem/19886775
Differential Revision: https://reviews.llvm.org/D32210
llvm-svn: 313722
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.
rdar://problem/19886775
Differential Revision: https://reviews.llvm.org/D32520
llvm-svn: 313720
This made it awkward to switch over an enum where some entries
are partial and is unlikley to catch any bugs.
Differential revision: https://reviews.llvm.org/D36777
llvm-svn: 311191
Base::TraverseStmt when visiting the then/else branches of if statements
This ensures that the statement stack is correctly tracked and correct
multi-statement fixit is generated inside of an if (@available)
llvm-svn: 311088
This reverts commit rL310403, which caused spurious warnings in libc++,
because it didn't properly handle templated scoped lockable types.
llvm-svn: 310698
Add warnings in cases where an implicit `this` argument is expected to
attributes because either `this` doesn't exist because the attribute is
on a free function, or because `this` is on a type that doesn't have a
corresponding capability/lockable/scoped_lockable attribute.
Reviewers: delesley, aaron.ballman
Differential Revision: https://reviews.llvm.org/D36237
llvm-svn: 310403
Delete the test that was broken by rL309725, and add it back in a
follow up commit. Also, improve the tests a bit.
Reviewers: delesley, aaron.ballman
Differential Revision: https://reviews.llvm.org/D36237
llvm-svn: 310402
An ABI change was introduced in r254596 that modified structure layouts when the 'packed' attribute was used on one-byte bitfields. Since the PS4 target needs to maintain backwards compatibility for all structure layouts, this change reintroduces the old behavior for PS4 targets only. It also introduces PS4 specific cases to the relevant test.
Patch by Matthew Voss.
llvm-svn: 310388
This patch adds support for the `long_call`, `far`, and `near` attributes
for MIPS targets. The `long_call` and `far` attributes are synonyms. All
these attributes override `-mlong-calls` / `-mno-long-calls` command
line options for particular function.
Differential revision: https://reviews.llvm.org/D35479
llvm-svn: 308667
Move builtins from the x86 specific scope into the global
scope. Their use is still limited to x86_64 and aarch64 though.
This allows wine on aarch64 to properly handle variadic functions.
Differential Revision: https://reviews.llvm.org/D34475
llvm-svn: 308218
be shared without warnings. Build AttributedTypes to leave breadcrumbs
for tools like the static analyzer. Warn about attempting to use the
attribute with incompatible return types.
llvm-svn: 308092
The new compiler warning -Wunguarded-availability-new is a subset of
-Wunguarded-availability. It is on by default. It only warns about uses of APIs
that have been introduced in macOS >= 10.13, iOS >= 11, watchOS >= 4 and
tvOS >= 11. We decided to use this kind of solution as we didn't want to turn
on -Wunguarded-availability by default, because we didn't want our users to get
warnings about uses of old APIs in their existing projects.
rdar://31054725
Differential Revision: https://reviews.llvm.org/D34264
llvm-svn: 306033
Summary:
Before this change, we couldn't capture the `this` pointer that's
implicitly the first argument of class member functions. There are some
interesting things we can do with capturing even just this single
argument for zero-argument member functions.
Reviewers: rnk, pelikan
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D34052
llvm-svn: 305544
This is an initial commit to allow using it with constant expressions, a follow-up commit will enable full support for it in ObjC methods.
llvm-svn: 303712
This patch adds support for the `micromips` and `nomicromips` attributes
for MIPS targets.
Differential revision: https://reviews.llvm.org/D33363
llvm-svn: 303546
`__builtin_available`
This commit allows us to use the macOS/iOS/tvOS/watchOS platform names in
`@available`/`__builtin_available`.
rdar://32067795
Differential Revision: https://reviews.llvm.org/D33000
llvm-svn: 302540
This patch adds a fix-it for the -Wunguarded-availability warning. This fix-it
is similar to the Swift one: it suggests that you wrap the statement in an
`if (@available)` check. The produced fixits are indented (just like the Swift
ones) to make them look nice in Xcode's fix-it preview.
rdar://31680358
Differential Revision: https://reviews.llvm.org/D32424
llvm-svn: 302253
blocks and lambdas
Prior to this commit Clang emitted the old "partial availability" warning for
expressions that referred to declarations that were not yet introduced in
blocks and lambdas that were not in a function/method. This commit ensures that
top-level blocks and lambdas use the new unguarded availability checks.
rdar://31835952
llvm-svn: 301409
Prior to this commit the external_source_symbol attribute wasn't supported by
#pragma clang attribute for the following two reasons:
- The Named attribute subject hasn't been supported by TableGen.
- There was no way to specify a subject match rule for #pragma clang attribute
that could operate on a set of attribute subjects (e.g. the ones that derive
from NamedDecl).
This commit fixes the two issues and thus adds external_source_symbol support to
#pragma clang attribute.
rdar://31169028
Differential Revision: https://reviews.llvm.org/D32176
llvm-svn: 300712
This is a recommit of r300539 that was reverted in r300543 due to test failures.
The original commit message is displayed below:
The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.
Differential Revision: https://reviews.llvm.org/D30009
llvm-svn: 300556
The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.
Differential Revision: https://reviews.llvm.org/D30009
llvm-svn: 300539
MSDN (https://msdn.microsoft.com/en-us/library/h5w10wxs.aspx) indicates
that `__declspec(naked)` is only permitted on x86 and ARM targets.
Testing with cl does confirm this behaviour. Provide a warning for use
of `__declspec(naked)` on x64.
llvm-svn: 299774
GCC has the alloc_align attribute, which is similar to assume_aligned, except the attribute's parameter is the index of the integer parameter that needs aligning to.
Differential Revision: https://reviews.llvm.org/D29599
llvm-svn: 299117
Summary:
This patch implements parsing of [[clang::suppress(rule, ...)]]
and [[gsl::suppress(rule, ...)]] attributes.
C++ Core Guidelines depend heavily on tool support for
rule enforcement. They also propose a way to suppress
warnings [1] which is by annotating any ancestor in AST
with the C++11 attribute [[gsl::suppress(rule1,...)]].
To have a mechanism to suppress non-C++ Core
Guidelines specific, an additional spelling of [[clang::suppress]]
is defined.
For example, to suppress the warning cppcoreguidelines-slicing,
one could do
```
[[clang::suppress("cppcoreguidelines-slicing")]]
void f() { ... code that does slicing ... }
```
or
```
void g() {
Derived b;
[[clang::suppress("cppcoreguidelines-slicing")]]
Base a{b};
[[clang::suppress("cppcoreguidelines-slicing")]] {
doSomething();
Base a2{b};
}
}
```
This parsing can then be used by clang-tidy, which includes multiple
C++ Core Guidelines rules, to suppress warnings (see
https://reviews.llvm.org/D24888).
For the exact naming of the rule in the attribute, there
are different possibilities, which will be defined in the
corresponding clang-tidy patch.
Currently, clang-tidy supports suppressing of warnings through "//
NOLINT" comments. There are some advantages that the attribute has:
- Suppressing specific warnings instead of all warnings
- Suppressing warnings in a block (namespace, function, compound
statement)
- Code formatting may split a statement into multiple lines,
thus a "// NOLINT" comment may be on the wrong line
I'm looking forward to your comments!
[1] https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#inforce-enforcement
Reviewers: alexfh, aaron.ballman, rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D24886
llvm-svn: 298880
Correct class-template deprecation behavior
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;
This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.
Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.
Previous DiffRev: https://reviews.llvm.org/D27486, was reverted.
This patch fixes the issues brought up here by the reverter: https://reviews.llvm.org/rL298410
Differential Revision: https://reviews.llvm.org/D31245
llvm-svn: 298634
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;
This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.
Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.
Differential Revision: https://reviews.llvm.org/D27486
llvm-svn: 298410
This commit adds support for a new attribute that will be used to
distinguish between extensible and inextensible enums. There are three
main purposes of this attribute:
1. Give better control over when enum-related warnings are issued.
For example, in the code below, clang will not issue a -Wassign-enum
warning if the enum is marked "open":
enum __attribute__((enum_extensibility(closed))) EnumClosed {
B0 = 1, B1 = 10
};
enum __attribute__((enum_extensibility(open))) EnumOpen {
C0 = 1, C1 = 10
};
enum EnumClosed ec = 100; // warning issued
enum EnumOpen eo = 100; // no warning
2. Enable code-completion and debugging tools to offer better
suggestions.
3. Make it easier for swift's clang importer to determine which swift
type an enum should be mapped to.
For more details, see the discussion I started on cfe-dev:
http://lists.llvm.org/pipermail/cfe-dev/2017-February/052748.html
rdar://problem/12764379
rdar://problem/23145650
Differential Revision: https://reviews.llvm.org/D30766
llvm-svn: 298332
Summary:
Functions with the "xray_log_args" attribute will tell LLVM to emit a special
XRay sled for compiler-rt to copy any call arguments to your logging handler.
Reviewers: dberris
Reviewed By: dberris
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D29704
llvm-svn: 296999
and the nature of a declaration
This commit adds an external_source_symbol attribute to Clang. This attribute
specifies that a declaration originates from an external source and describes
the nature of that source. This attribute will be used to improve IDE features
like 'jump-to-definition' for mixed-language projects or project that use
auto-generated code.
rdar://30423368
Differential Revision: https://reviews.llvm.org/D29819
llvm-svn: 296649
instantiation.
In preparation for converting the template stack to a more general context
stack (so we can include context notes for other kinds of context).
llvm-svn: 295686
Summary:
This teaches clang how to parse and lower the 'interrupt' and 'naked'
attributes.
This allows interrupt signal handlers to be written.
Reviewers: aaron.ballman
Subscribers: malcolm.parsons, cfe-commits
Differential Revision: https://reviews.llvm.org/D28451
llvm-svn: 294402
`diagnose_if` can be used to have clang emit either warnings or errors
for function calls that meet user-specified conditions. For example:
```
constexpr int foo(int a)
__attribute__((diagnose_if(a > 10, "configurations with a > 10 are "
"expensive.", "warning")));
int f1 = foo(9);
int f2 = foo(10); // warning: configuration with a > 10 are expensive.
int f3 = foo(f2);
```
It currently only emits diagnostics in cases where the condition is
guaranteed to always be true. So, the following code will emit no
warnings:
```
constexpr int bar(int a) {
foo(a);
return 0;
}
constexpr int i = bar(10);
```
We hope to support optionally emitting diagnostics for cases like that
(and emitting runtime checks) in the future.
Release notes will appear shortly. :)
Differential Revision: https://reviews.llvm.org/D27424
llvm-svn: 291418
This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.
Fingers crossed that this patch sticks this time. :)
Original commit message:
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
llvm-svn: 290297
This commit fails MSan when running test/CodeGen/object-size.c in
a confusing way. After some discussion with George, it isn't really
clear what is going on here. We can make the MSan failure go away by
testing for the invalid bit, but *why* things are invalid isn't clear.
And yet, other code in the surrounding area is doing precisely this and
testing for invalid.
George is going to take a closer look at this to better understand the
nature of the failure and recommit it, for now backing it out to clean
up MSan builds.
llvm-svn: 290169
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
Differential Revision: https://reviews.llvm.org/D14274
llvm-svn: 290149
Although not specifically mentioned in the documentation, MSVC accepts
__uuidof(…) and declspec(uuid("…")) attributes on enumeration types in
addition to structs/classes. This is meaningful, as such types *do* have
associated UUIDs in ActiveX typelibs, and such attributes are included
by default in the wrappers generated by their #import construct, so they
are not particularly unusual.
clang currently rejects the declspec with a –Wignored-attributes
warning, and errors on __uuidof() with “cannot call operator __uuidof on
a type with no GUID” (because it rejected the uuid attribute, and
therefore finds no value). This is causing problems for us while trying
to use clang-tidy on a codebase that makes heavy use of ActiveX.
I believe I have found the relevant places to add this functionality,
this patch adds this case to clang’s implementation of these MS
extensions. patch is against r285994 (or actually the git mirror
80464680ce).
Both include an update to test/Parser/MicrosoftExtensions.cpp to
exercise the new functionality.
This is my first time contributing to LLVM, so if I’ve missed anything
else needed to prepare this for review just let me know!
__uuidof: https://msdn.microsoft.com/en-us/library/zaah6a61.aspx
declspec(uuid("…")): https://msdn.microsoft.com/en-us/library/3b6wkewa.aspx
#import: https://msdn.microsoft.com/en-us/library/8etzzkb6.aspx
Reviewers: aaron.ballman, majnemer, rnk
Differential Revision: https://reviews.llvm.org/D26846
llvm-svn: 289567
This patch implements the register call calling convention, which ensures
as many values as possible are passed in registers. CodeGen changes
were committed in https://reviews.llvm.org/rL284108.
Differential Revision: https://reviews.llvm.org/D25204
llvm-svn: 285849
Certain OpenCL builtin functions are supposed to be executed by all threads in a work group or sub group. Such functions should not be made divergent during transformation. It makes sense to mark them with convergent attribute.
The adding of convergent attribute is based on Ettore Speziale's work and the original proposal and patch can be found at https://www.mail-archive.com/cfe-commits@lists.llvm.org/msg22271.html.
Differential Revision: https://reviews.llvm.org/D25343
llvm-svn: 285725
This is done so that the following compiles with no warnings:
int fn(type_10_12) __attribute__((availability(macos, introduced=10.12)));
Differential revision: https://reviews.llvm.org/D25284
llvm-svn: 285457
This patch adds an objc_subclassing_restricted attribute into clang. This
attribute acts similarly to 'final' - Objective-C classes with this attribute
can't be subclassed. However, @interface declarations that have
objc_subclassing_restricted but don't have @implementation are allowed to
inherit other @interface declarations with objc_subclassing_restricted. This is
needed to describe the Swift class hierarchy in clang while making sure that
the Objective-C classes cannot subclass the Swift classes.
This attribute is already implemented in a fork of clang that's used for Swift
(https://github.com/apple/swift-clang) and this patch moves that code to the
upstream clang repository.
rdar://28937548
Differential Revision: https://reviews.llvm.org/D25993
llvm-svn: 285391
The problem with the original commit was that some of Apple's headers depended
on an incorrect behaviour, this commit adds a temporary workaround until those
headers are fixed.
llvm-svn: 285098
This reverts commit r285007 and reapply r284990, with a fix for the
opencl test that I broke. Original commit message follows:
These new builtins support a mechanism for logging OS events, using a
printf-like format string to specify the layout of data in a buffer.
The _buffer_size version of the builtin can be used to determine the size
of the buffer to allocate to hold the data, and then __builtin_os_log_format
can write data into that buffer. This implements format checking to report
mismatches between the format string and the data arguments. Most of this
code was written by Chris Willmore.
Differential Revision: https://reviews.llvm.org/D25888
llvm-svn: 285019
Sander de Smalen