[WPD/VFE] Always emit vcall_visibility metadata for -fwhole-program-vtables

Summary:
First patch to support Safe Whole Program Devirtualization Enablement,
see RFC here: http://lists.llvm.org/piperm

[WPD/VFE] Always emit vcall_visibility metadata for -fwhole-program-vtables

Summary:
First patch to support Safe Whole Program Devirtualization Enablement,
see RFC here: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html

Always emit !vcall_visibility metadata under -fwhole-program-vtables,
and not just for -fvirtual-function-elimination. The vcall visibility
metadata will (in a subsequent patch) be used to communicate to WPD
which vtables are safe to devirtualize, and we will optionally convert
the metadata to hidden visibility at link time. Subsequent follow on
patches will help enable this by adding vcall_visibility metadata to the
ThinLTO summaries, and always emit type test intrinsics under
-fwhole-program-vtables (and not just for vtables with hidden
visibility).

In order to do this safely with VFE, since for VFE all vtable loads must
be type checked loads which will no longer be the case, this patch adds
a new "Virtual Function Elim" module flag to communicate to GlobalDCE
whether to perform VFE using the vcall_visibility metadata.

One additional advantage of using the vcall_visibility metadata to drive
more WPD at LTO link time is that we can use the same mechanism to
enable more aggressive VFE at LTO link time as well. The link time
option proposed in the RFC will convert vcall_visibility metadata to
hidden (aka linkage unit visibility), which combined with
-fvirtual-function-elimination will allow it to be done more
aggressively at LTO link time under the same conditions.

Reviewers: pcc, ostannard, evgeny777, steven_wu

Subscribers: mehdi_amini, Prazek, hiraditya, dexonsmith, davidxl, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71907

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[RISCV] Pass target-abi via module flag metadata

Reviewers: lenary, asb

Reviewed By: lenary

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72755

Consolidate internal denormal flushing controls

Currently there are 4 different mechanisms for controlling denormal
flushing behavior, and about as many equivalent frontend controls.

- AMDGPU uses

Consolidate internal denormal flushing controls

Currently there are 4 different mechanisms for controlling denormal
flushing behavior, and about as many equivalent frontend controls.

- AMDGPU uses the fp32-denormals and fp64-f16-denormals subtarget features
- NVPTX uses the nvptx-f32ftz attribute
- ARM directly uses the denormal-fp-math attribute
- Other targets indirectly use denormal-fp-math in one DAGCombine
- cl-denorms-are-zero has a corresponding denorms-are-zero attribute

AMDGPU wants a distinct control for f32 flushing from f16/f64, and as
far as I can tell the same is true for NVPTX (based on the attribute
name).

Work on consolidating these into the denormal-fp-math attribute, and a
new type specific denormal-fp-math-f32 variant. Only ARM seems to
support the two different flush modes, so this is overkill for the
other use cases. Ideally we would error on the unsupported
positive-zero mode on other targets from somewhere.

Move the logic for selecting the flush mode into the compiler driver,
instead of handling it in cc1. denormal-fp-math/denormal-fp-math-f32
are now both cc1 flags, but denormal-fp-math-f32 is not yet exposed as
a user flag.

-cl-denorms-are-zero, -fcuda-flush-denormals-to-zero and
-fno-cuda-flush-denormals-to-zero will be mapped to
-fp-denormal-math-f32=ieee or preserve-sign rather than the old
attributes.

Stop emitting the denorms-are-zero attribute for the OpenCL flag. It
has no in-tree users. The meaning would also be target dependent, such
as the AMDGPU choice to treat this as only meaning allow flushing of
f32 and not f16 or f64. The naming is also potentially confusing,
since DAZ in other contexts refers to instructions implicitly treating
input denormals as zero, not necessarily flushing output denormals to
zero.

This also does not attempt to change the behavior for the current
attribute. The LangRef now states that the default is ieee behavior,
but this is inaccurate for the current implementation. The clang
handling is slightly hacky to avoid touching the existing
denormal-fp-math uses. Fixing this will be left for a future patch.

AMDGPU is still using the subtarget feature to control the denormal
mode, but the new attribute are now emitted. A future change will
switch this and remove the subtarget features.

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Reapply Allow system header to provide their own implementation of some builtin

This reverts commit 3d210ed3d1880c615776b07d1916edb400c245a6.

See https://reviews.llvm.org/D71082 for the patch and d

Reapply Allow system header to provide their own implementation of some builtin

This reverts commit 3d210ed3d1880c615776b07d1916edb400c245a6.

See https://reviews.llvm.org/D71082 for the patch and discussion that make it
possible to reapply this patch.

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[OPENMP]Do not emit RTTI descriptor for NVPTX devices.

Need to disable emission of RTTI descriptors for NVPTX devices to be
able to use dynamic classes without unresolved symbols at link stage.

Fix "pointer is null" static analyzer warnings. NFCI.

Use castAs<> instead of getAs<> since the pointer is dereferenced immediately in all cases and castAs will perform the null assertion for us.

Revert "Allow system header to provide their own implementation of some builtin"

This reverts commit 921f871ac438175ca8fcfcafdfcfac4d7ddf3905 because it
causes libc++ code to trigger __warn_memset_z

Revert "Allow system header to provide their own implementation of some builtin"

This reverts commit 921f871ac438175ca8fcfcafdfcfac4d7ddf3905 because it
causes libc++ code to trigger __warn_memset_zero_len.

See https://reviews.llvm.org/D71082.

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[DebugInfo] Add another level to DebugInfoKind called Constructor

The option will limit debug info by only emitting complete class
type information when its constructor is emitted.
This patch change

[DebugInfo] Add another level to DebugInfoKind called Constructor

The option will limit debug info by only emitting complete class
type information when its constructor is emitted.
This patch changes comparisons with LimitedDebugInfo to use the new
level instead.

Differential Revision: https://reviews.llvm.org/D72427

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Allow system header to provide their own implementation of some builtin

If a system header provides an (inline) implementation of some of their
function, clang still matches on the function name and

Allow system header to provide their own implementation of some builtin

If a system header provides an (inline) implementation of some of their
function, clang still matches on the function name and generate the appropriate
llvm builtin, e.g. memcpy. This behavior is in line with glibc recommendation «
users may not provide their own version of symbols » but doesn't account for the
fact that glibc itself can provide inline version of some functions.

It is the case for the memcpy function when -D_FORTIFY_SOURCE=1 is on. In that
case an inline version of memcpy calls __memcpy_chk, a function that performs
extra runtime checks. Clang currently ignores the inline version and thus
provides no runtime check.

This code fixes the issue by detecting functions whose name is a builtin name
but also have an inline implementation.

Differential Revision: https://reviews.llvm.org/D71082

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[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize.

The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But t

[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize.

The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But this can be affected by the
target attribute so we need to factor that in.

This patch moves some of the code from CodeGen to create an
appropriate feature map that we can pass to the function.

Differential Revision: https://reviews.llvm.org/D68627

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reland "[DebugInfo] Support to emit debugInfo for extern variables"

Commit d77ae1552fc21a9f3877f3ed7e13d631f517c825
("[DebugInfo] Support to emit debugInfo for extern variables")
added deebugInfo fo

reland "[DebugInfo] Support to emit debugInfo for extern variables"

Commit d77ae1552fc21a9f3877f3ed7e13d631f517c825
("[DebugInfo] Support to emit debugInfo for extern variables")
added deebugInfo for extern variables for BPF target.
The commit is reverted by 891e25b02d760d0de18c7d46947913b3166047e7
as the committed tests using %clang instead of %clang_cc1 causing
test failed in certain scenarios as reported by Reid Kleckner.

This patch fixed the tests by using %clang_cc1.

Differential Revision: https://reviews.llvm.org/D71818

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Revert "[DebugInfo] Support to emit debugInfo for extern variables"

This reverts commit d77ae1552fc21a9f3877f3ed7e13d631f517c825.

The tests committed along with this change do not pass, and should

Revert "[DebugInfo] Support to emit debugInfo for extern variables"

This reverts commit d77ae1552fc21a9f3877f3ed7e13d631f517c825.

The tests committed along with this change do not pass, and should be
changed to use %clang_cc1.

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[OpenMP] Use the OpenMP-IR-Builder

This is a follow up patch to use the OpenMP-IR-Builder, as discussed on
the mailing list ([1] and later) and at the US Dev Meeting'19.

[1] http://lists.flang-comp

[OpenMP] Use the OpenMP-IR-Builder

This is a follow up patch to use the OpenMP-IR-Builder, as discussed on
the mailing list ([1] and later) and at the US Dev Meeting'19.

[1] http://lists.flang-compiler.org/pipermail/flang-dev_lists.flang-compiler.org/2019-May/000197.html

Reviewers: kiranchandramohan, ABataev, RaviNarayanaswamy, gtbercea, grokos, sdmitriev, JonChesterfield, hfinkel, fghanim

Subscribers: ppenzin, penzn, llvm-commits, cfe-commits, jfb, guansong, bollu, hiraditya, mgorny

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69922

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CodeGen: Allow annotations on globals in non-zero address space

Summary:
Attribute annotations are recorded in a special global composite variable
that points to annotation strings and the annotated

CodeGen: Allow annotations on globals in non-zero address space

Summary:
Attribute annotations are recorded in a special global composite variable
that points to annotation strings and the annotated objects.

As a restriction of the LLVM IR type system, those pointers are all
pointers to address space 0, so let's insert an addrspacecast when the
annotated global is in a non-0 address space.

Since this addrspacecast is only reachable from the global annotations
object, this should allow us to represent annotations on all globals
regardless of which addrspacecasts are usually legal for the target.

Reviewers: rjmccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D71208

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[DebugInfo] Support to emit debugInfo for extern variables

Extern variable usage in BPF is different from traditional
pure user space application. Recent discussion in linux bpf
mailing list has two

[DebugInfo] Support to emit debugInfo for extern variables

Extern variable usage in BPF is different from traditional
pure user space application. Recent discussion in linux bpf
mailing list has two use cases where debug info types are
required to use extern variables:
- extern types are required to have a suitable interface
in libbpf (bpf loader) to provide kernel config parameters
to bpf programs.
https://lore.kernel.org/bpf/CAEf4BzYCNo5GeVGMhp3fhysQ=_axAf=23PtwaZs-yAyafmXC9g@mail.gmail.com/T/#t
- extern types are required so kernel bpf verifier can
verify program which uses external functions more precisely.
This will make later link with actual external function no
need to reverify.
https://lore.kernel.org/bpf/[email protected]/T/#m8d5c3e87ffe7f2764e02d722cb0d8cbc136880ed

This patch added clang support to emit debuginfo for extern variables
with a TargetInfo hook to enable it. The debuginfo for the
extern variable is emitted only if that extern variable is
referenced in the current compilation unit.

Currently, only BPF target enables to generate debug info for
extern variables. The emission of such debuginfo is disabled for C++
at this moment since BPF only supports a subset of C language.
Emission with C++ can be enabled later if an appropriate use case
is identified.

-fstandalone-debug permits us to see more debuginfo with the cost
of bloated binary size. This patch did not add emission of extern
variable debug info with -fstandalone-debug. This can be
re-evaluated if there is a real need.

Differential Revision: https://reviews.llvm.org/D70696

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[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

Revert "[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize."

This reverts commit e1578fd2b79fe5af5f80c0c166a8abd0f816c022.

It introduces a dependency

Revert "[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize."

This reverts commit e1578fd2b79fe5af5f80c0c166a8abd0f816c022.

It introduces a dependency on Attr.h which I am removing from
ASTContext.h.

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[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize.

The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But t

[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize.

The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But this can be affected by the
target attribute so we need to factor that in.

This patch copies some of the code from CodeGen to create an
appropriate feature map that we can pass to the function. Probably
need some refactoring here to share more code with Codegen. Is
there a good place to do that? Also need to support the cpu_specific
attribute as well.

Differential Revision: https://reviews.llvm.org/D68627

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[Clang] Define Fuchsia C++ABI

Currently, it is a modified version of the Itanium ABI, with the only
change being that constructors and destructors return 'this'.

Differential Revision: https://revi

[Clang] Define Fuchsia C++ABI

Currently, it is a modified version of the Itanium ABI, with the only
change being that constructors and destructors return 'this'.

Differential Revision: https://reviews.llvm.org/D70575

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[OPENMP]Fix PR41826: symbols visibility in device code.

Summary:
Currently, we ignore all locality attributes/info when building for
the device and thus all symblos are externally visible and can be

[OPENMP]Fix PR41826: symbols visibility in device code.

Summary:
Currently, we ignore all locality attributes/info when building for
the device and thus all symblos are externally visible and can be
preemted at the runtime. It may lead to incorrect results. We need to
follow the same logic, compiler uses for static/pie builds. But in some
cases changing of dso locality may lead to problems with codegen, so
instead mark external symbols as hidden instead in the device code.

Reviewers: jdoerfert

Subscribers: guansong, caomhin, kkwli0, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70549

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DebugInfo: Flag Dwarf Version metadata for merging during LTO

When the Dwarf Version metadata was initially added (r184276) there was
no support for Module::Max - though the comment suggested that w

DebugInfo: Flag Dwarf Version metadata for merging during LTO

When the Dwarf Version metadata was initially added (r184276) there was
no support for Module::Max - though the comment suggested that was the
desired behavior. The original behavior was Module::Warn which would
warn and then pick whichever version came first - which is pretty
arbitrary/luck-based if the consumer has some need for one version or
the other.

Now that the functionality's been added (r303590) this change updates
the implementation to match the desired goal.

The general logic here is - if you compile /some/ of your program with a
more recent DWARF version, you must have a consumer that can handle it,
so might as well use it for /everything/.

The only place where this might fall down is if you have a need to use
an old tool (supporting only the older DWARF version) for some subset of
your program. In which case now it'll all be the higher version. That
seems pretty narrow (& the inverse could happen too - you specifically
/need/ the higher DWARF version for some extra expressivity, etc, in
some part of the program)

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[DeclCXX] Remove unknown external linkage specifications

Partial revert of r372681 "Support for DWARF-5 C++ language tags".

The change introduced new external linkage languages ("C++11" and
"C++14"

[DeclCXX] Remove unknown external linkage specifications

Partial revert of r372681 "Support for DWARF-5 C++ language tags".

The change introduced new external linkage languages ("C++11" and
"C++14") which not supported in C++.

It also changed the definition of the existing enum to use the DWARF
constants. The problem is that "LinkageSpecDeclBits.Language" (the field
that reserves this enum) is actually defined as 3 bits length
(bitfield), which cannot contain the new DWARF constants. Defining the
enum as integer literals is more appropriate for maintaining valid
values.

Differential Revision: https://reviews.llvm.org/D69935

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[NFC] Refactor representation of materialized temporaries

Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63

[NFC] Refactor representation of materialized temporaries

Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63640#inline-612718

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: thakis, sammccall, ilya-biryukov, rnkovacs, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69360

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Revert "[NFC] Refactor representation of materialized temporaries"

This reverts commit 08ea1ee2db5f9d6460fef1d79d0d1d1a5eb78982.
It broke ./ClangdTests/FindExplicitReferencesTest.All
on the bots, se

Revert "[NFC] Refactor representation of materialized temporaries"

This reverts commit 08ea1ee2db5f9d6460fef1d79d0d1d1a5eb78982.
It broke ./ClangdTests/FindExplicitReferencesTest.All
on the bots, see comments on https://reviews.llvm.org/D69360

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[NFC] Refactor representation of materialized temporaries

Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63

[NFC] Refactor representation of materialized temporaries

Summary:
this patch refactor representation of materialized temporaries to prevent an issue raised by rsmith in https://reviews.llvm.org/D63640#inline-612718

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: rnkovacs, arphaman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69360

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