Commit Graph

1386 Commits

Author SHA1 Message Date
Alex Richardson a602f76a24 [clang][TargetInfo] Use LangAS for getPointer{Width,Align}()
Mixing LLVM and Clang address spaces can result in subtle bugs, and there
is no need for this hook to use the LLVM IR level address spaces.
Most of this change is just replacing zero with LangAS::Default,
but it also allows us to remove a few calls to getTargetAddressSpace().

This also removes a stale comment+workaround in
CGDebugInfo::CreatePointerLikeType(): ASTContext::getTypeSize() does
return the expected size for ReferenceType (and handles address spaces).

Differential Revision: https://reviews.llvm.org/D138295
2022-11-30 20:24:01 +00:00
Rageking8 94738a5ac3 Fix duplicate word typos; NFC
This revision fixes typos where there are 2 consecutive words which are
duplicated. There should be no code changes in this revision (only
changes to comments and docs). Do let me know if there are any
undesirable changes in this revision. Thanks.
2022-11-08 07:21:23 -05:00
Nathan James 108e41d962
[clang][NFC] Use c++17 style variable type traits
This was done as a test for D137302 and it makes sense to push these changes

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D137491
2022-11-07 18:25:48 +00:00
Yuanfang Chen 5d086cce8b [Clang] perform "maximum TLS alignment" check for template instantiation
follow up d30e2eefc3

Reviewed By: mizvekov

Differential Revision: https://reviews.llvm.org/D136744
2022-10-30 22:39:47 -07:00
Xiang Li 14ae5d2b74 [HLSL] Add SV_DispatchThreadID
Support SV_DispatchThreadID attribute.
Translate it into dx.thread.id in clang codeGen.

Reviewed By: beanz, aaron.ballman

Differential Revision: https://reviews.llvm.org/D133983
2022-10-18 16:17:19 -07:00
Chris Bieneman 19a0a56749 [HLSL] Add utility to convert environment to stage
We had a bunch of places in the code where we were translating triple
environment enum cases to shader stage enum cases. The order of these
enums needs to be kept in sync for the translation to be simple, but we
were not properly handling out-of-bounds cases.

In normal compilation out-of-bounds cases shouldn't be possible because
the driver errors if you don't have a valid shader environment set, but
in clang tooling that error doesn't get treated as fatal and parsing
continues. This can result in crashes in clang tooling for out-of-range
shader stages.

To address this, this patch adds a constexpr method to handle the
conversion which handles out-of-range values by converting them to
`Invalid`.

Since this new method is a constexpr, the tests for this are a group of
static_asserts in the implementation file that verifies the correct
conversion for each valid enum case and validates that other cases are
converted to `Invalid`.

Reviewed By: bogner

Differential Revision: https://reviews.llvm.org/D135595
2022-10-12 16:31:30 -05:00
David Green 781b491bba [Clang][AArch64] Support AArch64 target(..) attribute formats.
This adds support under AArch64 for the target("..") attributes. The
current parsing is very X86-shaped, this patch attempts to bring it line
with the GCC implementation from
https://gcc.gnu.org/onlinedocs/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes.

The supported formats are:
- "arch=<arch>" strings, that specify the architecture features for a
  function as per the -march=arch+feature option.
- "cpu=<cpu>" strings, that specify the target-cpu and any implied
  atributes as per the -mcpu=cpu+feature option.
- "tune=<cpu>" strings, that specify the tune-cpu cpu for a function as
  per -mtune.
- "+<feature>", "+no<feature>" enables/disables the specific feature, for
  compatibility with GCC target attributes.
- "<feature>", "no-<feature>" enabled/disables the specific feature, for
  backward compatibility with previous releases.

To do this, the parsing of target attributes has been moved into
TargetInfo to give the target the opportunity to override the existing
parsing. The only non-aarch64 change should be a minor alteration to the
error message, specifying using "CPU" to describe the cpu, not
"architecture", and the DuplicateArch/Tune from ParsedTargetAttr have
been combined into a single option.

Differential Revision: https://reviews.llvm.org/D133848
2022-10-01 15:40:59 +01:00
Xiang Li e3fd0b2073 [HLSL] Add resource binding attribute for HLSL.
The resource binding attribute is to set the virtual registers and logical register spaces resources in HLSL are bound to.
Format is ''register(ID,  space)'' like register(t3,  space1).
ID must be start with
t – for shader resource views (SRV),
s – for samplers,
u – for unordered access views (UAV),
b – for constant buffer views (CBV).

Register space is default to space0.

The full documentation is available here: https://docs.microsoft.com/en-us/windows/win32/direct3d12/resource-binding-in-hlsl

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D130033
2022-09-22 11:51:21 -07:00
Xiang Li 52d7ce0cc1 [HLSL] Allow SV_GroupIndex for lib profile.
Lib profile could include all kind of entry functions.

Reviewed By: beanz

Differential Revision: https://reviews.llvm.org/D134326
2022-09-21 12:29:58 -07:00
Chris Bieneman d3c54a172d [HLSL] Call global constructors inside entry
HLSL doesn't have a runtime loader model that supports global
construction by a loader or runtime initializer. To allow us to leverage
global constructors with minimal code generation impact we put calls to
the global constructors inside the generated entry function.

Differential Revision: https://reviews.llvm.org/D132977
2022-09-09 09:01:28 -05:00
Kazu Hirata b7a7aeee90 [clang] Qualify auto in range-based for loops (NFC) 2022-09-03 23:27:27 -07:00
Kazu Hirata 89f1433225 Use llvm::lower_bound (NFC) 2022-09-03 11:17:37 -07:00
Alex Brachet f6d6e33abc [clang] Give better message for unsupported no_sanitize on globals
Previously if you specified no_sanitize("known_sanitizer") on a global you
would yield a misleading error "'no_sanitize' attribute only applies to
functions and methods", but no_sanitize("unknown") would simply be a warning,
"unknown sanitizer 'unknown' ignored". This changes the former to a warning
"'no_sanitize' attribute argument not supported for globals: known_sanitizer".

Differential Revision: https://reviews.llvm.org/D133117
2022-09-01 22:35:42 +00:00
Xiang Li 8a27a2f89f [HLSL] Support -E option for HLSL.
-E option will set entry function for hlsl.
The format is -E entry_name.

To avoid conflict with existing option with name 'E', add an extra prefix '--'.

A new field HLSLEntry is added to TargetOption.
To share code with HLSLShaderAttr, entry function will be add HLSLShaderAttr attribute too.

Reviewed By: beanz

Differential Revision: https://reviews.llvm.org/D124751
2022-08-04 16:54:19 -07:00
Kazu Hirata 16eaeaded5 Use is_contained (NFC) 2022-07-30 10:35:54 -07:00
skc7 09c4121123 Revert "Revert "[Clang][Attribute] Introduce maybe_undef attribute for function arguments which accepts undef values""
This reverts commit 4e1fe96.

Reverting this commit and fix the tests that caused failures due to
a35c64c.
2022-07-29 19:07:07 +00:00
Amy Kwan 4e1fe968c9 Revert "[Clang][Attribute] Introduce maybe_undef attribute for function arguments which accepts undef values"
This reverts commit a35c64ce23.

Reverting this commit as it causes various failures on LE and BE PPC bots.
2022-07-29 13:28:48 -05:00
skc7 a35c64ce23 [Clang][Attribute] Introduce maybe_undef attribute for function arguments which accepts undef values
Add the ability to put __attribute__((maybe_undef)) on function arguments.
Clang codegen introduces a freeze instruction on the argument.

Differential Revision: https://reviews.llvm.org/D130224
2022-07-29 02:27:26 +00:00
Kazu Hirata cb2c8f694d [clang] Use value instead of getValue (NFC) 2022-07-13 23:39:33 -07:00
Zarko Todorovski a61b202d4e [Clang][Sema][AIX][PowerPC] Emit byval alignment warning only when struct is passed to a function
Previous warning went on whenever a struct with a struct member with alignment => 16
was declared. This led to too many false positives and led to diagnostic lit failures
due to it being emitted too frequently. Only emit the warning when such a struct and
that struct contains a member that has an alignment of 16 bytes is passed to a caller
function since this is where the potential binary compatibility issue with XL 16.1.0
and older exists.

Reviewed By: sfertile, aaron.ballman

Differential Revision: https://reviews.llvm.org/D118350
2022-07-13 15:32:29 -04:00
Nick Desaulniers 2240d72f15 [X86] initial -mfunction-return=thunk-extern support
Adds support for:
* `-mfunction-return=<value>` command line flag, and
* `__attribute__((function_return("<value>")))` function attribute

Where the supported <value>s are:
* keep (disable)
* thunk-extern (enable)

thunk-extern enables clang to change ret instructions into jmps to an
external symbol named __x86_return_thunk, implemented as a new
MachineFunctionPass named "x86-return-thunks", keyed off the new IR
attribute fn_ret_thunk_extern.

The symbol __x86_return_thunk is expected to be provided by the runtime
the compiled code is linked against and is not defined by the compiler.
Enabling this option alone doesn't provide mitigations without
corresponding definitions of __x86_return_thunk!

This new MachineFunctionPass is very similar to "x86-lvi-ret".

The <value>s "thunk" and "thunk-inline" are currently unsupported. It's
not clear yet that they are necessary: whether the thunk pattern they
would emit is beneficial or used anywhere.

Should the <value>s "thunk" and "thunk-inline" become necessary,
x86-return-thunks could probably be merged into x86-retpoline-thunks
which has pre-existing machinery for emitting thunks (which could be
used to implement the <value> "thunk").

Has been found to build+boot with corresponding Linux
kernel patches. This helps the Linux kernel mitigate RETBLEED.
* CVE-2022-23816
* CVE-2022-28693
* CVE-2022-29901

See also:
* "RETBLEED: Arbitrary Speculative Code Execution with Return
Instructions."
* AMD SECURITY NOTICE AMD-SN-1037: AMD CPU Branch Type Confusion
* TECHNICAL GUIDANCE FOR MITIGATING BRANCH TYPE CONFUSION REVISION 1.0
  2022-07-12
* Return Stack Buffer Underflow / Return Stack Buffer Underflow /
  CVE-2022-29901, CVE-2022-28693 / INTEL-SA-00702

SystemZ may eventually want to support "thunk-extern" and "thunk"; both
options are used by the Linux kernel's CONFIG_EXPOLINE.

This functionality has been available in GCC since the 8.1 release, and
was backported to the 7.3 release.

Many thanks for folks that provided discrete review off list due to the
embargoed nature of this hardware vulnerability. Many Bothans died to
bring us this information.

Link: https://www.youtube.com/watch?v=IF6HbCKQHK8
Link: https://github.com/llvm/llvm-project/issues/54404
Link: https://gcc.gnu.org/legacy-ml/gcc-patches/2018-01/msg01197.html
Link: https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/advisory-guidance/return-stack-buffer-underflow.html
Link: https://arstechnica.com/information-technology/2022/07/intel-and-amd-cpus-vulnerable-to-a-new-speculative-execution-attack/?comments=1
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ce114c866860aa9eae3f50974efc68241186ba60
Link: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00702.html
Link: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00707.html

Reviewed By: aaron.ballman, craig.topper

Differential Revision: https://reviews.llvm.org/D129572
2022-07-12 09:17:54 -07:00
Félix Cloutier 92edd74b37 Allow non-variadic functions to be attributed with `__attribute__((format))`
Clang only allows you to use __attribute__((format)) on variadic functions. There are legit use cases for __attribute__((format)) on non-variadic functions, such as:

(1) variadic templates

```c++
template<typename… Args>
void print(const char *fmt, Args… &&args) __attribute__((format(1, 2))); // error: format attribute requires variadic function
```

(2) functions which take fixed arguments and a custom format:

```c++
void print_number_string(const char *fmt, unsigned number, const char *string) __attribute__((format(1, 2)));
// ^error: format attribute requires variadic function

void foo(void) {
    print_number_string(“%08x %s\n”, 0xdeadbeef, “hello”);
    print_number_string(“%d %s”, 0xcafebabe, “bar”);
}
```

This change allows Clang users to attach __attribute__((format)) to non-variadic functions, including functions with C++ variadic templates. It replaces the error with a GCC compatibility warning and improves the type checker to ensure that received arrays are treated like pointers (this is a possibility in C++ since references to template types can bind to arrays).

Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D112579
rdar://84629099
2022-07-05 17:26:11 -07:00
Xiang Li a591c7ca0d [HLSL] Change WaveActiveCountBits to wrapper of __builtin_hlsl_wave_active_count_bits
Change WaveActiveCountBits from builtin into wrapper of __builtin_hlsl_wave_active_count_bits.
For comment at
https://reviews.llvm.org/D126857#inline-1235949

Reviewed By: beanz

Differential Revision: https://reviews.llvm.org/D128855
2022-06-30 06:16:51 -07:00
Corentin Jabot a9a60f20e6 [Clang] Rename StringLiteral::isAscii() => isOrdinary() [NFC]
"Ascii" StringLiteral instances are actually narrow strings
that are UTF-8 encoded and do not have an encoding prefix.
(UTF8 StringLiteral are also UTF-8 encoded strings, but with
the u8 prefix.

To avoid possible confusion both with actuall ASCII strings,
and with future works extending the set of literal encodings
supported by clang, this rename StringLiteral::isAscii() to
isOrdinary(), matching C++ standard terminology.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D128762
2022-06-29 18:28:51 +02:00
Kazu Hirata 97afce08cb [clang] Don't use Optional::hasValue (NFC)
This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.
2022-06-25 22:26:24 -07:00
Kazu Hirata 3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3.
2022-06-25 11:56:50 -07:00
Kazu Hirata aa8feeefd3 Don't use Optional::hasValue (NFC) 2022-06-25 11:55:57 -07:00
Mitch Phillips faf5e0ec73 Add no_sanitize('hwaddress') (and 'memtag', but that's a no-op).
Currently, `__attribute__((no_sanitize('hwaddress')))` is not possible. Add this piece of plumbing, and now that we properly support copying attributes between an old and a new global variable, add a regression test for the GlobalOpt bug that previously lost the attribute.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D127544
2022-06-24 12:04:11 -07:00
Kazu Hirata ca4af13e48 [clang] Don't use Optional::getValue (NFC) 2022-06-20 22:59:26 -07:00
Mitch Phillips ee28837a1f [NFCI] Whitespace in SemaDeclAttr.cpp 2022-06-16 15:10:32 -07:00
Martin Boehme 8c7b64b5ae [clang] Reject non-declaration C++11 attributes on declarations
For backwards compatiblity, we emit only a warning instead of an error if the
attribute is one of the existing type attributes that we have historically
allowed to "slide" to the `DeclSpec` just as if it had been specified in GNU
syntax. (We will call these "legacy type attributes" below.)

The high-level changes that achieve this are:

- We introduce a new field `Declarator::DeclarationAttrs` (with appropriate
  accessors) to store C++11 attributes occurring in the attribute-specifier-seq
  at the beginning of a simple-declaration (and other similar declarations).
  Previously, these attributes were placed on the `DeclSpec`, which made it
  impossible to reconstruct later on whether the attributes had in fact been
  placed on the decl-specifier-seq or ahead of the declaration.

- In the parser, we propgate declaration attributes and decl-specifier-seq
  attributes separately until we can place them in
  `Declarator::DeclarationAttrs` or `DeclSpec::Attrs`, respectively.

- In `ProcessDeclAttributes()`, in addition to processing declarator attributes,
  we now also process the attributes from `Declarator::DeclarationAttrs` (except
  if they are legacy type attributes).

- In `ConvertDeclSpecToType()`, in addition to processing `DeclSpec` attributes,
  we also process any legacy type attributes that occur in
  `Declarator::DeclarationAttrs` (and emit a warning).

- We make `ProcessDeclAttribute` emit an error if it sees any non-declaration
  attributes in C++11 syntax, except in the following cases:
  - If it is being called for attributes on a `DeclSpec` or `DeclaratorChunk`
  - If the attribute is a legacy type attribute (in which case we only emit
    a warning)

The standard justifies treating attributes at the beginning of a
simple-declaration and attributes after a declarator-id the same. Here are some
relevant parts of the standard:

- The attribute-specifier-seq at the beginning of a simple-declaration
  "appertains to each of the entities declared by the declarators of the
  init-declarator-list" (https://eel.is/c++draft/dcl.dcl#dcl.pre-3)

- "In the declaration for an entity, attributes appertaining to that entity can
  appear at the start of the declaration and after the declarator-id for that
  declaration." (https://eel.is/c++draft/dcl.dcl#dcl.pre-note-2)

- "The optional attribute-specifier-seq following a declarator-id appertains to
  the entity that is declared."
  (https://eel.is/c++draft/dcl.dcl#dcl.meaning.general-1)

The standard contains similar wording to that for a simple-declaration in other
similar types of declarations, for example:

- "The optional attribute-specifier-seq in a parameter-declaration appertains to
  the parameter." (https://eel.is/c++draft/dcl.fct#3)

- "The optional attribute-specifier-seq in an exception-declaration appertains
  to the parameter of the catch clause" (https://eel.is/c++draft/except.pre#1)

The new behavior is tested both on the newly added type attribute
`annotate_type`, for which we emit errors, and for the legacy type attribute
`address_space` (chosen somewhat randomly from the various legacy type
attributes), for which we emit warnings.

Depends On D111548

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D126061
2022-06-15 11:58:26 +02:00
Martin Boehme 665da187cc [Clang] Add the `annotate_type` attribute
This is an analog to the `annotate` attribute but for types. The intent is to allow adding arbitrary annotations to types for use in static analysis tools.

For details, see this RFC:

https://discourse.llvm.org/t/rfc-new-attribute-annotate-type-iteration-2/61378

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D111548
2022-06-15 09:47:28 +02:00
Kazu Hirata d93728978b [clang] Use llvm::is_contained (NFC) 2022-06-05 17:56:40 -07:00
Paul Robinson aa1cdf87b5 [PS5] Ignore 'packed' on one-byte bitfields, matching PS4 2022-06-02 14:41:18 -07:00
David Blaikie cb08f4aa44 Support warn_unused_result on typedefs
While it's not as robust as using the attribute on enums/classes (the
type information may be lost through a function pointer, a declaration
or use of the underlying type without using the typedef, etc) but I
think there's still value in being able to attribute a typedef and have
all return types written with that typedef pick up the
warn_unused_result behavior.

Specifically I'd like to be able to annotate LLVMErrorRef (a wrapper for
llvm::Error used in the C API - the underlying type is a raw pointer, so
it can't be attributed itself) to reduce the chance of unhandled errors.

Differential Revision: https://reviews.llvm.org/D102122
2022-06-02 20:57:31 +00:00
Jon Chesterfield 83c431fb9e [amdgpu] Add amdgpu_kernel calling conv attribute to clang
Allows emitting define amdgpu_kernel void @func() IR from C or C++.

This replaces the current workflow which is to write a stub in opencl that
calls an external C function implemented in C++ combined through llvm-link.

Calling the resulting function still requires a manual implementation of the
ABI from the host side. The primary application is for more rapid debugging
of the amdgpu backend by permuting a C or C++ test file instead of manually
updating an IR file.

Implementation closely follows D54425. Non-amd reviewers from there.

Reviewed By: yaxunl

Differential Revision: https://reviews.llvm.org/D125970
2022-05-20 08:50:37 +01:00
Félix Cloutier 91ed7e1941 [clang] Allow all string types for all attribute(format) styles
This allows using any recognized kind of string for any
__attribute__((format)) archetype. Before this change, for instance,
the printf archetype would only accept char pointer types and the
NSString archetype would only accept NSString pointers. This is
more restrictive than necessary as there exist functions to
convert between string types that can be annotated with
__attribute__((format_arg)) to transfer format information.

Reviewed By: ahatanak

Differential Revision: https://reviews.llvm.org/D125254

rdar://89060618
2022-05-12 11:12:38 -07:00
Matt Devereau 75bb815231 [AArch64][SVE] Add aarch64_sve_pcs attribute to Clang
Enable function attribute aarch64_sve_pcs at the C level, which correspondes to
aarch64_sve_vector_pcs at the LLVM IR level.

This requirement was created by this addition to the ARM C Language Extension:
https://github.com/ARM-software/acle/pull/194

Differential Revision: https://reviews.llvm.org/D124998
2022-05-11 13:33:56 +00:00
Xiang Li b02d88d5af [HLSL] Add shader attribute
Shader attribute is for shader library identify entry functions.
Here's an example,

[shader("pixel")]
float ps_main() : SV_Target {
  return 1;
}

When compile this shader to library target like -E lib_6_3, compiler needs to know ps_main is an entry function for pixel shader. Shader attribute is to offer the information.

A new attribute HLSLShader is added to support shader attribute. It has an EnumArgument which included all possible shader stages.

Reviewed By: aaron.ballman, MaskRay

Differential Revision: https://reviews.llvm.org/D123907
2022-04-20 23:46:43 -07:00
Chris Bieneman 1fdf952dee [HLSL] Add Semantic syntax, and SV_GroupIndex
HLSL has a language feature called Semantics which get attached to
declarations like attributes and are used in a variety of ways.

One example of semantic use is here with the `SV_GroupIndex` semantic
which, when applied to an input for a compute shader is pre-populated
by the driver with a flattened thread index.

Differential Revision: https://reviews.llvm.org/D122699

# Conflicts:
#	clang/include/clang/Basic/Attr.td
#	clang/include/clang/Basic/AttrDocs.td
2022-04-14 10:21:58 -05:00
Connor Kuehl 7aa8c38a9e [randstruct] Add randomize structure layout support
The Randstruct feature is a compile-time hardening technique that
randomizes the field layout for designated structures of a code base.
Admittedly, this is mostly useful for closed-source releases of code,
since the randomization seed would need to be available for public and
open source applications.

Why implement it? This patch set enhances Clang’s feature parity with
that of GCC which already has the Randstruct feature. It's used by the
Linux kernel in certain structures to help thwart attacks that depend on
structure layouts in memory.

This patch set is a from-scratch reimplementation of the Randstruct
feature that was originally ported to GCC. The patches for the GCC
implementation can be found here:

  https://www.openwall.com/lists/kernel-hardening/2017/04/06/14

Link: https://lists.llvm.org/pipermail/cfe-dev/2019-March/061607.html
Co-authored-by: Cole Nixon <nixontcole@gmail.com>
Co-authored-by: Connor Kuehl <cipkuehl@gmail.com>
Co-authored-by: James Foster <jafosterja@gmail.com>
Co-authored-by: Jeff Takahashi <jeffrey.takahashi@gmail.com>
Co-authored-by: Jordan Cantrell <jordan.cantrell@mail.com>
Co-authored-by: Nikk Forbus <nicholas.forbus@gmail.com>
Co-authored-by: Tim Pugh <nwtpugh@gmail.com>
Co-authored-by: Bill Wendling <isanbard@gmail.com>
Signed-off-by: Bill Wendling <isanbard@gmail.com>

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D121556
2022-04-09 13:15:36 -07:00
Fangrui Song a58d0af058 Revert D121556 "[randstruct] Add randomize structure layout support"
This reverts commit 3f0587d0c6.

Not all tests pass after a few rounds of fixes.

I spot one failure that std::shuffle (potentially different results with
different STL implementations) was misused and replaced it with llvm::shuffle,
but there appears to be another failure in a Windows build.

The latest failure is reported on https://reviews.llvm.org/D121556#3440383
2022-04-08 18:37:26 -07:00
Connor Kuehl 3f0587d0c6 [randstruct] Add randomize structure layout support
The Randstruct feature is a compile-time hardening technique that
randomizes the field layout for designated structures of a code base.
Admittedly, this is mostly useful for closed-source releases of code,
since the randomization seed would need to be available for public and
open source applications.

Why implement it? This patch set enhances Clang’s feature parity with
that of GCC which already has the Randstruct feature. It's used by the
Linux kernel in certain structures to help thwart attacks that depend on
structure layouts in memory.

This patch set is a from-scratch reimplementation of the Randstruct
feature that was originally ported to GCC. The patches for the GCC
implementation can be found here:

  https://www.openwall.com/lists/kernel-hardening/2017/04/06/14

Link: https://lists.llvm.org/pipermail/cfe-dev/2019-March/061607.html
Co-authored-by: Cole Nixon <nixontcole@gmail.com>
Co-authored-by: Connor Kuehl <cipkuehl@gmail.com>
Co-authored-by: James Foster <jafosterja@gmail.com>
Co-authored-by: Jeff Takahashi <jeffrey.takahashi@gmail.com>
Co-authored-by: Jordan Cantrell <jordan.cantrell@mail.com>
Co-authored-by: Nikk Forbus <nicholas.forbus@gmail.com>
Co-authored-by: Tim Pugh <nwtpugh@gmail.com>
Co-authored-by: Bill Wendling <isanbard@gmail.com>
Signed-off-by: Bill Wendling <isanbard@gmail.com>

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D121556
2022-04-08 12:48:30 -07:00
Chris Bieneman 19054163e1 [HLSL] Further improve to numthreads diagnostics
This adds diagnostics for conflicting attributes on the same
declarataion, conflicting attributes on a forward and final
declaration, and defines a more narrowly scoped HLSLEntry attribute
target.

Big shout out to @aaron.ballman for the great feedback and review on
this!
2022-03-31 11:34:01 -05:00
Chris Bieneman 94189b42cc [HLSL] Fix MSFT Attribute parsing, add numthreads
HLSL uses Microsoft-style attributes `[attr]`, which clang mostly
ignores. For HLSL we need to handle known Microsoft attributes, and to
maintain C/C++ as-is we ignore unknown attributes.

To utilize this new code path, this change adds the HLSL `numthreads`
attribute.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D122627
2022-03-29 17:17:19 -05:00
Hubert Tong ce21c926f8 [Clang] Work with multiple pragmas weak before definition
Update `WeakUndeclaredIdentifiers` to hold a collection of weak
aliases per identifier instead of only one.

This also allows the "used" state to be removed from `WeakInfo`
because it is really only there as an alternative to removing
processed map entries, and we can represent that using an empty set
now. The serialization code is updated for the removal of the field.
Additionally, a PCH test is added for the new functionality.

The records are grouped by the "target" identifier, which was already
being used as a key for lookup purposes. We also store only one record
per alias name; combined, this means that diagnostics are grouped by
the "target" and limited to one per alias (which should be acceptable).

Fixes PR28611.
Fixes llvm/llvm-project#28985.

Reviewed By: aaron.ballman, cebowleratibm

Differential Revision: https://reviews.llvm.org/D121927

Co-authored-by: Rachel Craik <rcraik@ca.ibm.com>
Co-authored-by: Jamie Schmeiser <schmeise@ca.ibm.com>
2022-03-24 20:17:49 -04:00
Aaron Ballman 5b164a3a9b Diagnose use of a naked attribute on a member function in ms-mode
This matches the behavior of cl.exe.
2022-03-24 11:52:43 -04:00
Hubert Tong da167a53c8 [Clang][NFC] Some `const` for `IdentifierInfo *`s feeding `DeclarationName`
`DeclarationName` already takes `const IdentifierInfo *`. Propagate the
`const` outward to various APIs.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122261
2022-03-23 11:07:56 -04:00
Vlad Serebrennikov a603f566db [clang] CWG 2354: prohibit alignas for enums
Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D121723
2022-03-16 15:48:18 +08:00
Aaron Ballman a766545402 Update the diagnostic behavior of [[noreturn]] in C2x
Post-commit review feedback suggested dropping the deprecated
diagnostic for the 'noreturn' macro (the diagnostic from the header
file suffices and the macro diagnostic could be confusing) and to only
issue the deprecated diagnostic for [[_Noreturn]] when the attribute
identifier is either directly written or not from a system macro.

Amends the commit made in 5029dce492.
2022-02-14 14:04:32 -05:00