Commit Graph

1299 Commits

Author SHA1 Message Date
Johannes Doerfert b9c77542e2 [Clang][Attr] Introduce the `assume` function attribute
The `assume` attribute is a way to provide additional, arbitrary
information to the optimizer. For now, assumptions are restricted to
strings which will be accumulated for a function and emitted as comma
separated string function attribute. The key of the LLVM-IR function
attribute is `llvm.assume`. Similar to `llvm.assume` and
`__builtin_assume`, the `assume` attribute provides a user defined
assumption to the compiler.

A follow up patch will introduce an LLVM-core API to query the
assumptions attached to a function. We also expect to add more options,
e.g., expression arguments, to the `assume` attribute later on.

The `omp [begin] asssumes` pragma will leverage this attribute and
expose the functionality in the absence of OpenMP.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D91979
2020-12-15 16:51:34 -06:00
Gulfem Savrun Yeniceri 7c0e3a77bc [clang][IR] Add support for leaf attribute
This patch adds support for leaf attribute as an optimization hint
in Clang/LLVM.

Differential Revision: https://reviews.llvm.org/D90275
2020-12-14 14:48:17 -08:00
Richard Smith 2a2c228c7a Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.

The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.

This is a re-commit. The previous commit was reverted because it exposed
a pre-existing bug that has since been fixed / worked around; see
PR48434.

Differential Revision: https://reviews.llvm.org/D91311
2020-12-09 12:22:35 -08:00
Richard Smith a1344779ab Revert "Add new 'preferred_name' attribute."
This change exposed a pre-existing issue with deserialization cycles
caused by a combination of attributes and template instantiations
violating the deserialization ordering restrictions; see PR48434 for
details.

A previous commit attempted to work around PR48434, but appears to have
only been a partial fix, and fixing this properly seems non-trivial.
Backing out for now to unblock things.

This reverts commit 98f76adf4e and
commit a64c26a47a.
2020-12-08 00:42:48 -08:00
Erik Pilkington 5a28e1d9e5 [clang] Add support for attribute 'swift_async'
This attributes specifies how (or if) a given function or method will be
imported into a swift async method. rdar://70111252

Differential revision: https://reviews.llvm.org/D92742
2020-12-07 17:19:26 -05:00
Richard Smith 98f76adf4e Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.

The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.

Differential Revision: https://reviews.llvm.org/D91311
2020-12-07 12:53:07 -08:00
Alex Lorenz eddd1d192b [clang] add a `swift_async_name` attribute
The swift_async_name attribute provides a name for a function/method that can be used
to call the async overload of this method from Swift. This name specified in this attribute
assumes that the last parameter in the function/method its applied to is removed when
Swift invokes it, as the the Swift's await/async transformation implicitly constructs the callback.

Differential Revision: https://reviews.llvm.org/D92355
2020-12-04 15:55:29 -08:00
Alex Lorenz 03dcd57ecf [clang] add a new `swift_attr` attribute
The swift_attr attribute is a generic annotation attribute that's not used by clang,
but is used by the Swift compiler. The Swift compiler can use these annotations to provide
various syntactic and semantic sugars for the imported Objective-C API declarations.

Differential Revision: https://reviews.llvm.org/D92354
2020-12-04 15:53:24 -08:00
Ben Dunbobbin d5aaf60214 [windows-itanium] handle dllimport/export code paths separately and share with PS4
Similar to Windows Itanium, PS4 is also an Itanium C++ ABI variant
which shares the goal of semantic compatibility with Microsoft C++
code that uses dllimport/export.

This change introduces a new function to determine from the triple
if an environment aims for compatibility with MS C++ code w.r.t to
these attributes and guards the relevant code paths using that
function.

Differential Revision: https://reviews.llvm.org/D90299
2020-11-30 14:36:39 +00:00
Xiangling Liao 17497ec514 [AIX][FE] Support constructor/destructor attribute
Support attribute((constructor)) and attribute((destructor)) on AIX

Differential Revision: https://reviews.llvm.org/D90892
2020-11-19 09:24:01 -05:00
Thorsten 41b65f166b Convert ConstexprKind from Specifiers.h to a scoped enum; NFC 2020-11-16 14:10:19 -05:00
Aaron Ballman 66b876c014 Pass the source range when diagnosing an unknown attribute
This way, the whole attribute gets highlighted with diagnostics instead
of just the scope name in an attribute like [[clang::unknown]].
2020-11-13 10:29:44 -08:00
Alex Lorenz 3df3b62018 [clang] ns_error_domain attribute also supports CFString typed variables
Differential Revision: https://reviews.llvm.org/D90891
2020-11-11 08:50:30 -08:00
Tyker d093401a26 [NFC] Remove string parameter of annotation attribute from AST childs.
this simplifies using annotation attributes when using clang as library
2020-11-09 16:39:59 +01:00
Artem Belevich be86b6773b [CUDA] Allow local static variables with target attributes.
While CUDA documentation claims that such variables are not allowed[1], NVCC has
been accepting them since CUDA-10.0[2] and some headers in CUDA-11 rely on this
working.

1. https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#static-variables-function
2. https://godbolt.org/z/zsodzc

Differential Revision: https://reviews.llvm.org/D88345
2020-11-03 10:30:38 -08:00
Artem Belevich 0a3ebb4d8d Revert "[CUDA] Allow local static variables with target attributes."
This reverts commit f38a9e5117
Which triggered assertions.
2020-11-02 15:09:07 -08:00
Artem Belevich f38a9e5117 [CUDA] Allow local static variables with target attributes.
While CUDA documentation claims that such variables are not allowed[1], NVCC has
been accepting them since CUDA-10.0[2] and some headers in CUDA-11 rely on this
working.

1. https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#static-variables-function
2. https://godbolt.org/z/zsodzc

Differential Revision: https://reviews.llvm.org/D88345
2020-11-02 14:37:13 -08:00
Tyker d3205bbca3 [Annotation] Allows annotation to carry some additional constant arguments.
This allows using annotation in a much more contexts than it currently has.
especially when annotation with template or constexpr.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D88645
2020-10-26 10:50:05 +01:00
Richard Smith fc031d29be Switch the default of VerifyIntegerConstantExpression from constant
folding to not constant folding.

Constant folding of ICEs is done as a GCC compatibility measure, but new
code was picking it up, presumably by accident, due to the bad default.

While here, also switch the flag from a bool to an enum to make it more
obvious what it means at call sites. This highlighted a couple of places
where our behavior is different between C++11 and C++14 due to switching
from checking for an ICE to checking for a converted constant
expression (where there is no 'fold' codepath).
2020-10-15 16:58:47 -07:00
Ben Dunbobbin bb148ad426 [windows-itanium] make dllimport/export handling closer to MS behavior
Differential Revision: https://reviews.llvm.org/D86828
2020-10-09 13:24:07 +01:00
Ben Dunbobbin a9f1bb92bf Revert "first upstream review"
Pushed by accident :(

This reverts commit 4eb627ed96.
2020-10-09 13:22:46 +01:00
Ben Dunbobbin 4eb627ed96 first upstream review 2020-10-09 13:21:03 +01:00
Nathan Lanza 14f6bfcb52 [clang] Implement objc_non_runtime_protocol to remove protocol metadata
Summary:
Motivated by the new objc_direct attribute, this change adds a new
attribute that remotes metadata from Protocols that the programmer knows
isn't going to be used at runtime. We simply have the frontend skip
generating any protocol metadata entries (e.g. OBJC_CLASS_NAME,
_OBJC_$_PROTOCOL_INSTANCE_METHDOS, _OBJC_PROTOCOL, etc) for a protocol
marked with `__attribute__((objc_non_runtime_protocol))`.

There are a few APIs used to retrieve a protocol at runtime.
`@protocol(SomeProtocol)` will now error out of the requested protocol
is marked with attribute. `objc_getProtocol` will return `NULL` which
is consistent with the behavior of a non-existing protocol.

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75574
2020-10-02 17:35:50 -04:00
Saleem Abdulrasool 58cdbf518b Sema: add support for `__attribute__((__swift_private__))`
This attribute allows declarations to be restricted to the framework
itself, enabling Swift to remove the declarations when importing
libraries.  This is useful in the case that the functions can be
implemented in a more natural way for Swift.

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87720
Reviewed By: Aaron Ballman
2020-09-25 22:33:53 +00:00
Saleem Abdulrasool 76eb163259 Sema: remove unnecessary parameter for SwiftName handling (NFCI)
This code never actually did anything in the implementation.

`mergeDeclAttribute` is declared as `static`, and referenced exactly
once in the file: from `Sema::mergeDeclAttributes`.

`Sema::mergeDeclAttributes` sets `LocalAMK` to `AMK_None`.  If the
attribute is `DeprecatedAttr`, `UnavailableAttr`, or `AvailabilityAttr`
then the `LocalAMK` is updated.  However, because we are dealing with a
`SwiftNameDeclAttr` here, `LocalAMK` remains `AMK_None`.  This is then
passed to the function which will as a result pass the value of
`AMK_None == AMK_Override` aka `false`.  Simply propagate the value
through and erase the dead codepath.

Thanks to Aaron Ballman for flagging the use of the availability merge
kind here leading to this simplification!

Differential Revision: https://reviews.llvm.org/D88263
Reviewed By: Aaron Ballman
2020-09-25 17:01:06 +00:00
Saleem Abdulrasool 296d8832a3 Sema: add support for `__attribute__((__swift_newtype__))`
Add the `swift_newtype` attribute which allows a type definition to be
imported into Swift as a new type.  The imported type must be either an
enumerated type (enum) or an object type (struct).

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87652
Reviewed By: Aaron Ballman
2020-09-24 15:17:35 +00:00
Mikhail Maltsev 8cc842a950 [clang][Sema] Use enumerator instead of hard-coded constant
Sema::DiagnoseSwiftName uses the constant 12 instead of the
corresponding enumerator ExpectedFunctionWithProtoType. This is
fragile and will fail if a new value gets added in the middle of the
enum.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D88164
2020-09-24 10:24:22 +01:00
Aaron Ballman af1d3e6559 Allow init_priority values <= 100 and > 65535 within system headers.
This also adds some bare-bones documentation for the attribute rather
than leaving it undocumented.
2020-09-23 15:26:50 -04:00
Saleem Abdulrasool 9bb5ecf1f7 Sema: introduce `__attribute__((__swift_name__))`
This introduces the new `swift_name` attribute that allows annotating
APIs with an alternate spelling for Swift.  This is used as part of the
importing mechanism to allow interfaces to be imported with a new name
into Swift.  It takes a parameter which is the Swift function name.
This parameter is validated to check if it matches the possible
transformed signature in Swift.

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87534
Reviewed By: Aaron Ballman, Dmitri Gribenko
2020-09-22 15:32:23 +00:00
Saleem Abdulrasool 77a01d9498 Sema: add support for `__attribute__((__swift_bridge__))`
This extends semantic analysis of attributes for Swift interoperability
by introducing the `swift_bridge` attribute.  This attribute enables
bridging Objective-C types to Swift specific types.

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87532
Reviewed By: Aaron Ballman
2020-09-16 17:54:57 +00:00
Saleem Abdulrasool 7d26d6a1b0 Sema: add support for `__attribute__((__swift_bridged_typedef__))`
Extend the semantic attributes that clang processes for Swift to include
`swift_bridged_typedef`.  This attribute enables typedefs to be bridged
into Swift with a bridged name.

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87396
Reviewed By: Aaron Ballman
2020-09-15 20:15:34 +00:00
Saleem Abdulrasool 916b434035 Sema: add support for `__attribute__((__swift_objc_members__))`
This adds the `__swift_objc_members__` attribute to the semantic
analysis.  It allows for annotating ObjC interfaces to provide Swift
semantics indicating that the types derived from this interface will be
back-bridged to Objective-C to allow interoperability with Objective-C
and Swift.

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87395
Reviewed By: Aaron Ballman, Dmitri Gribenko
2020-09-14 15:24:41 +00:00
Saleem Abdulrasool f5ab5b20fb Sema: add support for `__attribute__((__swift_error__))`
Introduce a new attribute that is used to indicate the error handling
convention used by a function.  This is used to translate the error
semantics from the decorated interface to a compatible Swift interface.

The supported error convention is one of:
- none: no error handling
- nonnull_error: a non-null error parameter indicates an error signifier
- null_result: a return value of NULL is an error signifier
- zero_result: a return value of 0 is an error signifier
- nonzero_result: a non-zero return value is an error signifier

Since this is the first of the attributes needed to support the semantic
annotation for Swift, this change also includes the necessary supporting
infrastructure for a new category of attributes (Swift).

This is based on the work of the original changes in
8afaf3aad2

Differential Revision: https://reviews.llvm.org/D87331
Reviewed By: John McCall, Aaron Ballman, Dmitri Gribenko
2020-09-11 21:20:38 +00:00
Craig Topper 724f570ad2 [X86] Add support 'tune' in target attribute
This adds parsing and codegen support for tune in target attribute.

I've implemented this so that arch in the target attribute implicitly disables tune from the command line. I'm not sure what gcc does here. But since -march implies -mtune. I assume 'arch' in the target attribute implies tune in the target attribute.

Differential Revision: https://reviews.llvm.org/D86187
2020-08-19 15:58:19 -07:00
Michael Forster a5b8757506 Introduce ns_error_domain attribute.
ns_error_domain can be used by, e.g. NS_ERROR_ENUM, in order to
identify a global declaration representing the domain constant.

Introduces the attribute, Sema handling, diagnostics, and test case.

This is cherry-picked from a14779f504
and adapted to updated Clang APIs.

Reviewed By: gribozavr2, aaron.ballman

Differential Revision: https://reviews.llvm.org/D84005
2020-08-13 15:05:12 +02:00
Bruno Ricci 517fe058d4
[clang][NFC] clang-format fix after eb10b065f2 2020-07-29 14:55:16 +01:00
Bruno Ricci eb10b065f2
[clang] Pass the NamedDecl* instead of the DeclarationName into many diagnostics.
Background:
-----------
There are two related argument types which can be sent into a diagnostic to
display the name of an entity: DeclarationName (ak_declarationname) or
NamedDecl* (ak_nameddecl) (there is also ak_identifierinfo for
IdentifierInfo*, but we are not concerned with it here).

A DeclarationName in a diagnostic will just be streamed to the output,
which will directly result in a call to DeclarationName::print.

A NamedDecl* in a diagnostic will also ultimately result in a call to
DeclarationName::print, but with two customisation points along the way:

The first customisation point is NamedDecl::getNameForDiagnostic which is
overloaded by FunctionDecl, ClassTemplateSpecializationDecl and
VarTemplateSpecializationDecl to print the template arguments, if any.

The second customisation point is NamedDecl::printName. By default it just
streams the stored DeclarationName into the output but it can be customised
to provide a user-friendly name for an entity. It is currently overloaded by
DecompositionDecl and MSGuidDecl.

What this patch does:
---------------------
For many diagnostics a DeclarationName is used instead of the NamedDecl*.
This bypasses the two customisation points mentioned above. This patches fix
this for diagnostics in Sema.cpp, SemaCast.cpp, SemaChecking.cpp, SemaDecl.cpp,
SemaDeclAttr.cpp, SemaDecl.cpp, SemaOverload.cpp and SemaStmt.cpp.

I have only modified diagnostics where I could construct a test-case which
demonstrates that the change is appropriate (either with this patch or the next
one).

Reviewed By: erichkeane, aaron.ballman

Differential Revision: https://reviews.llvm.org/D84656
2020-07-28 10:30:35 +01:00
David Blaikie 36036aa70e Reapply "Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression"
Reapply 49e5f603d4
which had been reverted in c94332919b.

Originally reverted because I hadn't updated it in quite a while when I
got around to committing it, so there were a bunch of missing changes to
new code since I'd written the patch.

Reviewers: aaron.ballman

Differential Revision: https://reviews.llvm.org/D76646
2020-07-21 20:57:12 -07:00
David Blaikie c94332919b Revert "Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression"
Broke buildbots since I hadn't updated this patch in a while. Sorry for
the noise.

This reverts commit 49e5f603d4.
2020-07-12 20:29:19 -07:00
David Blaikie 49e5f603d4 Rename/refactor isIntegerConstantExpression to getIntegerConstantExpression
There is a version that just tests (also called
isIntegerConstantExpression) & whereas this version is specifically used
when the value is of interest (a few call sites were actually refactored
to calling the test-only version) so let's make the API look more like
it.

Reviewers: aaron.ballman

Differential Revision: https://reviews.llvm.org/D76646
2020-07-12 19:43:24 -07:00
Xiangling Liao 22337bfe7d [AIX][Frontend] Static init implementation for AIX considering no priority
1. Provides no piroirity supoort && disables three priority related
   attributes: init_priority, ctor attr, dtor attr;
2. '-qunique' in XL compiler equivalent behavior of emitting sinit
    and sterm functions name using getUniqueModuleId() util function
    in LLVM (currently no support for InternalLinkage and WeakODRLinkage
    symbols);
3. Add testcases to emit IR sample with __sinit80000000, __dtor, and
    __sterm80000000;
4. Temporarily side-steps the need to implement the functionality of
   llvm.global_ctors and llvm.global_dtors arrays. The uses of that
   functionality in this patch (with respect to the name of the functions
   involved) are not representative of how the functionality will be used
   once implemented.

Differential Revision: https://reviews.llvm.org/D74166
2020-06-19 08:27:07 -04:00
Dan Gohman 0d4e243456 [WebAssembly] Improve clang diagnostics for wasm attributes
This patch addresses the review comments on r352930:

 - Removes redundant diagnostic checking code
 - Removes errnoneous use of diag::err_alias_is_definition, which
   turned out to be ineffective anyway since functions can be defined later
   in the translation unit and avoid detection.
 - Adds a test for various invalid cases for import_name and import_module.

This reapplies D59520, with the addition of adding
`InGroup<IgnoredAttributes>` to the new warnings, to fix the
Misc/warning-flags.c failure.

Differential Revision: https://reviews.llvm.org/D59520
2020-06-05 14:32:51 -07:00
Dan Gohman 3aec298349 Revert "[WebAssembly] Improve clang diagnostics for wasm attributes"
It broke clang-check.

This reverts commit 931fcd3ba0.
2020-06-05 11:52:11 -07:00
Dan Gohman 931fcd3ba0 [WebAssembly] Improve clang diagnostics for wasm attributes
This patch addresses the review comments on r352930:

 - Removes redundant diagnostic checking code
 - Removes errnoneous use of diag::err_alias_is_definition, which
   turned out to be ineffective anyway since functions can be defined later
   in the translation unit and avoid detection.
 - Adds a test for various invalid cases for import_name and import_module.

Differential Revision: https://reviews.llvm.org/D59520
2020-06-05 11:27:51 -07:00
Nemanja Ivanovic 9021ce9576 [Clang] Enable KF and KC mode for [_Complex] __float128
The headers provided with recent GNU toolchains for PPC have code that includes
typedefs such as:

typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__KC__)))

This patch allows clang to compile programs that contain
#include <math.h>

with -mfloat128 which it currently fails to compile.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=46068

Differential revision: https://reviews.llvm.org/D80374
2020-05-28 15:48:15 -05:00
Yaxun (Sam) Liu 1b7bf1bd75 [HIP] Do not emit debug info for stub function
The stub function is generated by compiler and its instructions have nothing
to do with the kernel source code.

Currently clang generates debug info for the stub function, which causes
confusion for the HIP debugger. For example, when users set break point
on a line of a kernel, the debugger should break on that line when the kernel is
executed and reaches that line, but instead the debugger breaks in the stub function.

This patch disables debug info for stub function for HIP.

Differential Revision: https://reviews.llvm.org/D79866
2020-05-13 17:55:40 -04:00
Momchil Velikov 102b4105e3 [CMSE] Clear padding bits of struct/unions/fp16 passed by value
When passing a value of a struct/union type from secure to non-secure
state (that is returning from a CMSE entry function or passing an
argument to CMSE-non-secure call), there is a potential sensitive
information leak via the padding bits in the structure. It is not
possible in the general case to ensure those bits are cleared by using
Standard C/C++.

This patch makes the compiler emit code to clear such padding
bits. Since type information is lost in LLVM IR, the code generation
is done by Clang.

For each interesting record type, we build a bitmask, in which all the
bits, corresponding to user declared members, are set. Values of
record types are returned by coercing them to an integer. After the
coercion, the coerced value is masked (with bitwise AND) and then
returned by the function. In a similar manner, values of record types
are passed as arguments by coercing them to an array of integers, and
the coerced values themselves are masked.

For union types, we effectively clear only bits, which aren't part of
any member, since we don't know which is the currently active one.
The compiler will issue a warning, whenever a union is passed to
non-secure state.

Values of half-precision floating-point types are passed in the least
significant bits of a 32-bit register (GPR or FPR) with the most
significant bits unspecified. Since this is also a potential leak of
sensitive information, this patch also clears those unspecified bits.

Differential Revision: https://reviews.llvm.org/D76369
2020-04-28 17:05:58 +01:00
Aaron Ballman 1b3f1f4436 Rename warning identifiers from cxx2a to cxx20; NFC. 2020-04-22 14:31:13 -04:00
Aaron Ballman 6a30894391 C++2a -> C++20 in some identifiers; NFC. 2020-04-21 15:37:19 -04:00
Erich Keane 5f0903e9be Reland Implement _ExtInt as an extended int type specifier.
I fixed the LLDB issue, so re-applying the patch.

This reverts commit a4b88c0449.
2020-04-17 10:45:48 -07:00
Sterling Augustine a4b88c0449 Revert "Implement _ExtInt as an extended int type specifier."
This reverts commit 61ba1481e2.

I'm reverting this because it breaks the lldb build with
incomplete switch coverage warnings. I would fix it forward,
but am not familiar enough with lldb to determine the correct
fix.

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:3958:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4633:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4889:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
2020-04-17 10:29:40 -07:00
Erich Keane 61ba1481e2 Implement _ExtInt as an extended int type specifier.
Introduction/Motivation:
LLVM-IR supports integers of non-power-of-2 bitwidth, in the iN syntax.
Integers of non-power-of-two aren't particularly interesting or useful
on most hardware, so much so that no language in Clang has been
motivated to expose it before.

However, in the case of FPGA hardware normal integer types where the
full bitwidth isn't used, is extremely wasteful and has severe
performance/space concerns.  Because of this, Intel has introduced this
functionality in the High Level Synthesis compiler[0]
under the name "Arbitrary Precision Integer" (ap_int for short). This
has been extremely useful and effective for our users, permitting them
to optimize their storage and operation space on an architecture where
both can be extremely expensive.

We are proposing upstreaming a more palatable version of this to the
community, in the form of this proposal and accompanying patch.  We are
proposing the syntax _ExtInt(N).  We intend to propose this to the WG14
committee[1], and the underscore-capital seems like the active direction
for a WG14 paper's acceptance.  An alternative that Richard Smith
suggested on the initial review was __int(N), however we believe that
is much less acceptable by WG14.  We considered _Int, however _Int is
used as an identifier in libstdc++ and there is no good way to fall
back to an identifier (since _Int(5) is indistinguishable from an
unnamed initializer of a template type named _Int).

[0]https://www.intel.com/content/www/us/en/software/programmable/quartus-prime/hls-compiler.html)
[1]http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2472.pdf

Differential Revision: https://reviews.llvm.org/D73967
2020-04-17 07:10:57 -07:00
Aaron Ballman 2ec5520a54 Disallow [[nodiscard]] on a function pointer declaration.
This is not allowed by [dcl.attr.nodiscard]p1 for the standard attribute, but
is still supported for the [[clang::warn_unused_result]] spelling.
2020-04-16 09:28:49 -04:00
Nate Voorhies 0b21f15e14 [NFC] Correcting minor typo.
Summary: Hande -> Handle

Reviewers: xazax.hun

Reviewed By: xazax.hun

Subscribers: rnkovacs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78233
2020-04-15 13:36:22 -07:00
Richard Smith bab6df86ae Rework how UuidAttr, CXXUuidofExpr, and GUID template arguments and constants are represented.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.

With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.

This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.

This fixes a few bugs and issues:
 * PR38490: we now support reading from GUID objects returned from
   __uuidof during constant evaluation.
 * Our Itanium mangling for a non-instantiation-dependent template
   argument involving __uuidof no longer depends on which CXXUuidofExpr
   template argument we happened to see first.
 * We now predeclare ::_GUID, and permit use of __uuidof without
   any header inclusion, better matching MSVC's behavior. We do not
   predefine ::__s_GUID, though; that seems like a step too far.
 * Our IR representation for GUID constants now uses the correct IR type
   wherever possible. We will still fall back to using the
      {i32, i16, i16, [8 x i8]}
   layout if a definition of struct _GUID is not available. This is not
   ideal: in principle the two layouts could have different padding.

Reviewers: rnk, jdoerfert

Subscribers: arphaman, cfe-commits, aeubanks

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78171
2020-04-15 12:20:42 -07:00
Michael Liao c97be2c377 [hip] Remove `hip_pinned_shadow`.
Summary:
- Use `device_builtin_surface` and `device_builtin_texture` for
  surface/texture reference support. So far, both the host and device
  use the same reference type, which could be revised later when
  interface/implementation is stablized.

Reviewers: yaxunl

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77583
2020-04-07 09:51:49 -04:00
Michael Liao 5be9b8cbe2 [cuda][hip] Add CUDA builtin surface/texture reference support.
Summary: - Re-commit after fix Sema checks on partial template specialization.

Reviewers: tra, rjmccall, yaxunl, a.sidorin

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76365
2020-03-27 17:18:49 -04:00
Artem Belevich fe8063e1a0 Revert "[cuda][hip] Add CUDA builtin surface/texture reference support."
This reverts commit 6a9ad5f3f4.
The patch breaks CUDA copmilation.

Differential Revision: https://reviews.llvm.org/D76365
2020-03-27 10:01:38 -07:00
Michael Liao 6a9ad5f3f4 [cuda][hip] Add CUDA builtin surface/texture reference support.
Summary:
- Even though the bindless surface/texture interfaces are promoted,
  there are still code using surface/texture references. For example,
  [PR#26400](https://bugs.llvm.org/show_bug.cgi?id=26400) reports the
  compilation issue for code using `tex2D` with texture references. For
  better compatibility, this patch proposes the support of
  surface/texture references.
- Due to the absent documentation and magic headers, it's believed that
  `nvcc` does use builtins for texture support. From the limited NVVM
  documentation[^nvvm] and NVPTX backend texture/surface related
  tests[^test], it's believed that surface/texture references are
  supported by replacing their reference types, which are annotated with
  `device_builtin_surface_type`/`device_builtin_texture_type`, with the
  corresponding handle-like object types, `cudaSurfaceObject_t` or
  `cudaTextureObject_t`, in the device-side compilation. On the host
  side, that global handle variables are registered and will be
  established and updated later when corresponding binding/unbinding
  APIs are called[^bind]. Surface/texture references are most like
  device global variables but represented in different types on the host
  and device sides.
- In this patch, the following changes are proposed to support that
  behavior:
  + Refine `device_builtin_surface_type` and
    `device_builtin_texture_type` attributes to be applied on `Type`
    decl only to check whether a variable is of the surface/texture
    reference type.
  + Add hooks in code generation to replace that reference types with
    the correponding object types as well as all accesses to them. In
    particular, `nvvm.texsurf.handle.internal` should be used to load
    object handles from global reference variables[^texsurf] as well as
    metadata annotations.
  + Generate host-side registration with proper template argument
    parsing.

---
[^nvvm]: https://docs.nvidia.com/cuda/pdf/NVVM_IR_Specification.pdf
[^test]: https://raw.githubusercontent.com/llvm/llvm-project/master/llvm/test/CodeGen/NVPTX/tex-read-cuda.ll
[^bind]: See section 3.2.11.1.2 ``Texture reference API` in [CUDA C Programming Guide](https://docs.nvidia.com/cuda/pdf/CUDA_C_Programming_Guide.pdf).
[^texsurf]: According to NVVM IR, `nvvm.texsurf.handle` should be used.  But, the current backend doesn't have that supported. We may revise that later.

Reviewers: tra, rjmccall, yaxunl, a.sidorin

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76365
2020-03-26 14:44:52 -04:00
Momchil Velikov 080d046c91 [ARM][CMSE] Implement CMSE attributes
This patch adds CMSE attributes `cmse_nonsecure_call` and
`cmse_nonsecure_entry`.  As usual, specification is available here:
https://developer.arm.com/docs/ecm0359818/latest

Patch by Javed Absar, Bradley Smith, David Green, Momchil Velikov,
possibly others.

Differential Revision: https://reviews.llvm.org/D71129
2020-03-24 10:21:26 +00:00
John Brawn fa0320dd8d Add ParsedAttrInfo::handleDeclAttribute
This makes it possible for plugin attributes to actually do something, and also
removes a lot of boilerplate for simple attributes in SemaDeclAttr.cpp.

Differential Revision: https://reviews.llvm.org/D31342
2020-03-23 13:23:11 +00:00
Sander de Smalen 981f0802b3 [SVE] Generate overloaded functions for ACLE intrinsics.
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
2020-03-19 09:36:23 +00:00
Jon Chesterfield c45eaeabb7 [Clang] Undef attribute for global variables
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
2020-03-17 21:22:23 +00:00
Aaron Ballman dab43c8592 Remove some explicit calls to getName() when printing diagnostics; NFC 2020-03-14 17:01:45 -04:00
Richard Sandiford 627b5c1206 [Sema][SVE] Reject aligned/_Alignas for sizeless types
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
2020-03-12 17:12:40 +00:00
Mikhail Maltsev 47edf5bafb [ARM,CDE] Generalize MVE intrinsics infrastructure to support CDE
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
2020-03-10 14:03:16 +00:00
Erik Pilkington 2e4f5e629d [Sema] Fix an assert when objc_externally_retained was applied to an unprototyped function
rdar://58893199
2020-02-28 15:49:16 -08:00
Justin Lebar 027eb71696 Use std::foo_t rather than std::foo in clang.
Summary: No functional change.

Reviewers: bkramer, MaskRay, martong, shafik

Subscribers: martong, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74414
2020-02-11 10:37:08 -08:00
Reid Kleckner dd8e0a0a23 [Sema] Split availability processing into SemaAvailability.cpp
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
2020-01-24 17:35:39 -08:00
Roman Lebedev 1d0972ff5e
[Sema] Introduce MaximumAlignment value, to be used instead of magical constants
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
2020-01-24 17:49:17 +03:00
Roman Lebedev 0a002f679b
[Sema] Try 2: Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`
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
2020-01-24 16:56:39 +03:00
Fangrui Song 69bf40c45f [Driver][CodeGen] Support -fpatchable-function-entry=N,M and __attribute__((patchable_function_entry(N,M))) where M>0
Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D73072
2020-01-23 17:02:54 -08:00
Roman Lebedev 1624cba782
Partially revert "[IR] Attribute/AttrBuilder: use Value::MaximumAlignment magic constant"
Apparently makes bots angry.

This reverts commit d096f8d306.
2020-01-23 23:30:42 +03:00
Roman Lebedev 210f0882c9
Revert "[Sema] Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`"
Likely makes bots angry.

This reverts commit a4cfb15d15.

# Conflicts:
#	clang/lib/Sema/SemaDeclAttr.cpp
2020-01-23 23:10:35 +03:00
Roman Lebedev b749af6a1f
[Sema] Don't disallow placing `__attribute__((alloc_align(param_idx)))` on `std::align_val_t`-typed parameters
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
2020-01-23 22:50:50 +03:00
Roman Lebedev d096f8d306
[IR] Attribute/AttrBuilder: use Value::MaximumAlignment magic constant
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
2020-01-23 22:50:49 +03:00
Roman Lebedev a4cfb15d15
[Sema] Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`
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
2020-01-23 22:50:48 +03:00
Etienne Pierre-Doray 5260bc2497 Allow arbitrary capability name in Thread Safety Analysis
Restricting the names of capabilities to only "role" or "mutex" makes
for awkward diagnostic text, such as with:
https://chromium-review.googlesource.com/c/chromium/src/+/1948098/19/base/sequence_checker_unittest.nc#33
2020-01-21 15:43:17 -05:00
Reid Kleckner f63d763738 [TableGen] Use a table to lookup MVE intrinsic names
Summary:
Speeds up compilation of SemaDeclAttr.cpp by nine seconds:
  0m49.555s - > 0m40.249s

Reviewers: simon_tatham, dmgreen, ostannard, MarkMurrayARM

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72984
2020-01-21 11:05:45 -08:00
Fangrui Song a44c434b68 Support function attribute patchable_function_entry
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
2020-01-10 09:57:34 -08:00
Andrew Paverd bdd88b7ed3 Add support for __declspec(guard(nocf))
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
2020-01-10 16:04:12 +00:00
Saar Raz b65b1f322b [Concepts] Function trailing requires clauses
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
2020-01-09 15:07:51 +02:00
Gabor Horvath 247a603254 [LifetimeAnalysis] Do not forbid void deref type in gsl::Pointer/gsl::Owner annotations
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
2020-01-07 08:32:40 -08:00
Zachary Henkel 0acfc49317 Allow redeclaration of __declspec(uuid)
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
2019-12-28 13:13:46 -08:00
Gabor Horvath fe17b30a79 [attributes][analyzer] Add annotations for handles.
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
2019-12-20 11:47:55 -08:00
Sam Clegg 0a1e349a79 [WebAssembly] Setting export_name implies llvm.used
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
2019-12-16 14:48:38 -08:00
Sam Clegg 881d877846 [WebAssembly] Add new `export_name` clang attribute for controlling wasm export names
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
2019-12-11 11:54:57 -08:00
Craig Topper 505aa2410d [Attr] Move ParsedTargetAttr out of the TargetAttr class
Need to forward declare it in ASTContext.h for D68627, so it can't be a nested struct.

Differential Revision: https://reviews.llvm.org/D71159
2019-12-09 12:40:41 -08:00
Mariya Podchishchaeva c094e7dc4b [SYCL] Add sycl_kernel attribute for accelerated code outlining
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>
2019-12-03 16:13:22 +03:00
Reid Kleckner a9cc64e50e Separate the MS inheritance model enum from the attribute, NFC
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.
2019-11-22 16:06:30 -08:00
Pierre Habouzit d4e1ba3fa9 Implement __attribute__((objc_direct)), __attribute__((objc_direct_members))
__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
2019-11-18 11:48:40 -08:00
Momchil Velikov aa6d48fa70 Implement target(branch-protection) attribute for AArch64
This patch implements `__attribute__((target("branch-protection=...")))`
in a manner, compatible with the analogous GCC feature:

https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes

Differential Revision: https://reviews.llvm.org/D68711
2019-11-15 15:40:46 +00:00
Yonghong Song 4e2ce228ae [BPF] Add preserve_access_index attribute for record definition
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
2019-11-13 08:23:44 -08:00
Yonghong Song 9434360401 Revert "[BPF] Add preserve_access_index attribute for record definition"
This reverts commit 4a5aa1a7bf.

There are some other test failures. Investigate them first.
2019-11-09 08:32:44 -08:00
Yonghong Song 4a5aa1a7bf [BPF] Add preserve_access_index attribute for record definition
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
2019-11-09 08:17:12 -08:00
Guillaume Chatelet 1c85a2e8dc isBuiltinFunc() uses StringRef instead of const char*
Summary: This prevents a bug when passing nullptr, StringRef ctor would call strlen(nullptr).

Reviewers: vlad.tsyrklevich

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69569
2019-10-29 17:36:55 +01:00
Guillaume Chatelet 98f3151a7d [clang] Add no_builtin attribute
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.
2019-10-29 15:50:29 +01:00
Vlad Tsyrklevich ad531fff81 Revert "[clang] Add no_builtin attribute"
This reverts commit bd87916109. It was
causing ASan/MSan failures on the sanitizer buildbots.
2019-10-28 15:21:59 -07:00
Guillaume Chatelet bd87916109 [clang] Add no_builtin attribute
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
2019-10-28 17:30:11 +01:00
Simon Tatham 08074cc965 [clang,ARM] Initial ACLE intrinsics for MVE.
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
2019-10-24 16:33:13 +01:00