Revert "[clang] Implement ElaboratedType sugaring for types written bare"

This reverts commit 7c51f02effdbd0d5e12bfd26f9c3b2ab5687c93f because it
stills breaks the LLDB tests. This was re-landed wi

Revert "[clang] Implement ElaboratedType sugaring for types written bare"

This reverts commit 7c51f02effdbd0d5e12bfd26f9c3b2ab5687c93f because it
stills breaks the LLDB tests. This was re-landed without addressing the
issue or even agreement on how to address the issue. More details and
discussion in https://reviews.llvm.org/D112374.

show more ...

[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which go

[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

---

Troubleshooting list to deal with any breakage seen with this patch:

1) The most likely effect one would see by this patch is a change in how
a type is printed. The type printer will, by design and default,
print types as written. There are customization options there, but
not that many, and they mainly apply to how to print a type that we
somehow failed to track how it was written. This patch fixes a
problem where we failed to distinguish between a type
that was written without any elaborated-type qualifiers,
such as a 'struct'/'class' tags and name spacifiers such as 'std::',
and one that has been stripped of any 'metadata' that identifies such,
the so called canonical types.
Example:
```
namespace foo {
struct A {};
A a;
};
```
If one were to print the type of `foo::a`, prior to this patch, this
would result in `foo::A`. This is how the type printer would have,
by default, printed the canonical type of A as well.
As soon as you add any name qualifiers to A, the type printer would
suddenly start accurately printing the type as written. This patch
will make it print it accurately even when written without
qualifiers, so we will just print `A` for the initial example, as
the user did not really write that `foo::` namespace qualifier.

2) This patch could expose a bug in some AST matcher. Matching types
is harder to get right when there is sugar involved. For example,
if you want to match a type against being a pointer to some type A,
then you have to account for getting a type that is sugar for a
pointer to A, or being a pointer to sugar to A, or both! Usually
you would get the second part wrong, and this would work for a
very simple test where you don't use any name qualifiers, but
you would discover is broken when you do. The usual fix is to
either use the matcher which strips sugar, which is annoying
to use as for example if you match an N level pointer, you have
to put N+1 such matchers in there, beginning to end and between
all those levels. But in a lot of cases, if the property you want
to match is present in the canonical type, it's easier and faster
to just match on that... This goes with what is said in 1), if
you want to match against the name of a type, and you want
the name string to be something stable, perhaps matching on
the name of the canonical type is the better choice.

3) This patch could exposed a bug in how you get the source range of some
TypeLoc. For some reason, a lot of code is using getLocalSourceRange(),
which only looks at the given TypeLoc node. This patch introduces a new,
and more common TypeLoc node which contains no source locations on itself.
This is not an inovation here, and some other, more rare TypeLoc nodes could
also have this property, but if you use getLocalSourceRange on them, it's not
going to return any valid locations, because it doesn't have any. The right fix
here is to always use getSourceRange() or getBeginLoc/getEndLoc which will dive
into the inner TypeLoc to get the source range if it doesn't find it on the
top level one. You can use getLocalSourceRange if you are really into
micro-optimizations and you have some outside knowledge that the TypeLocs you are
dealing with will always include some source location.

4) Exposed a bug somewhere in the use of the normal clang type class API, where you
have some type, you want to see if that type is some particular kind, you try a
`dyn_cast` such as `dyn_cast<TypedefType>` and that fails because now you have an
ElaboratedType which has a TypeDefType inside of it, which is what you wanted to match.
Again, like 2), this would usually have been tested poorly with some simple tests with
no qualifications, and would have been broken had there been any other kind of type sugar,
be it an ElaboratedType or a TemplateSpecializationType or a SubstTemplateParmType.
The usual fix here is to use `getAs` instead of `dyn_cast`, which will look deeper
into the type. Or use `getAsAdjusted` when dealing with TypeLocs.
For some reason the API is inconsistent there and on TypeLocs getAs behaves like a dyn_cast.

5) It could be a bug in this patch perhaps.

Let me know if you need any help!

Signed-off-by: Matheus Izvekov <[email protected]>

Differential Revision: https://reviews.llvm.org/D112374

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Revert "[clang] Implement ElaboratedType sugaring for types written bare"

This reverts commit bdc6974f92304f4ed542241b9b89ba58ba6b20aa because it
breaks all the LLDB tests that import the std module

Revert "[clang] Implement ElaboratedType sugaring for types written bare"

This reverts commit bdc6974f92304f4ed542241b9b89ba58ba6b20aa because it
breaks all the LLDB tests that import the std module.

import-std-module/array.TestArrayFromStdModule.py
import-std-module/deque-basic.TestDequeFromStdModule.py
import-std-module/deque-dbg-info-content.TestDbgInfoContentDequeFromStdModule.py
import-std-module/forward_list.TestForwardListFromStdModule.py
import-std-module/forward_list-dbg-info-content.TestDbgInfoContentForwardListFromStdModule.py
import-std-module/list.TestListFromStdModule.py
import-std-module/list-dbg-info-content.TestDbgInfoContentListFromStdModule.py
import-std-module/queue.TestQueueFromStdModule.py
import-std-module/stack.TestStackFromStdModule.py
import-std-module/vector.TestVectorFromStdModule.py
import-std-module/vector-bool.TestVectorBoolFromStdModule.py
import-std-module/vector-dbg-info-content.TestDbgInfoContentVectorFromStdModule.py
import-std-module/vector-of-vectors.TestVectorOfVectorsFromStdModule.py

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/45301/

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[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which go

[clang] Implement ElaboratedType sugaring for types written bare

Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.

The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.

An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.

Signed-off-by: Matheus Izvekov <[email protected]>

Differential Revision: https://reviews.llvm.org/D112374

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[Clang] NFCI: Add a new bit HasExtraBitfields to FunctionType.

The FunctionTypeExtraBitfields is currently only available when the
ExceptionSpecificationType == Dynamic, which means that there is no

[Clang] NFCI: Add a new bit HasExtraBitfields to FunctionType.

The FunctionTypeExtraBitfields is currently only available when the
ExceptionSpecificationType == Dynamic, which means that there is no other
way to use or extend the FunctionTypeExtraBitfields independently of the
exception specification type.

This patch adds a new field HasExtraBitfields to specify
whether the prototype has trailing ExtraBitfields.

This patch intends to be NFC and is required for future extension
and use of the ExtraBitfields struct.

Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D126642

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[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

[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

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[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 w

[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

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re-roll-forward "[clang] Mark `trivial_abi` types as "trivially relocatable"".""

This reverts commit b0bc93da926a943cdc2d8b04f8dcbe23a774520c.

Changes: `s/_WIN32/_WIN64/g` in clang/test/SemaCXX/att

re-roll-forward "[clang] Mark `trivial_abi` types as "trivially relocatable"".""

This reverts commit b0bc93da926a943cdc2d8b04f8dcbe23a774520c.

Changes: `s/_WIN32/_WIN64/g` in clang/test/SemaCXX/attr-trivial-abi.cpp.

The calling convention is specific to 64-bit windows. It's even in the name: `CCK_MicrosoftWin64`.

After this, the test passes with both `-triple i686-pc-win32` and `-triple x86_64-pc-win32`. Phew!

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D123059

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Reland "[AST] Add a new TemplateKind for template decls found via a using decl.""

This is the template version of https://reviews.llvm.org/D114251.

This patch introduces a new template name kind (U

Reland "[AST] Add a new TemplateKind for template decls found via a using decl.""

This is the template version of https://reviews.llvm.org/D114251.

This patch introduces a new template name kind (UsingTemplateName). The
UsingTemplateName stores the found using-shadow decl (and underlying
template can be retrieved from the using-shadow decl). With the new
template name, we can be able to find the using decl that a template
typeloc (e.g. TemplateSpecializationTypeLoc) found its underlying template,
which is useful for tooling use cases (include cleaner etc).

This patch merely focuses on adding the node to the AST.

Next steps:
- support using-decl in qualified template name;
- update the clangd and other tools to use this new node;
- add ast matchers for matching different kinds of template names;

Differential Revision: https://reviews.llvm.org/D123127

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Revert "[AST] Add a new TemplateKind for template decls found via a using decl."

It breaks arm build, there is no free bit for the extra
UsingShadowDecl in TemplateName::StorageType.

Reverting it t

Revert "[AST] Add a new TemplateKind for template decls found via a using decl."

It breaks arm build, there is no free bit for the extra
UsingShadowDecl in TemplateName::StorageType.

Reverting it to build the buildbot back until we comeup with a fix.

This reverts commit 5a5be4044f0bceb71bb6a81f6955704691b389ed.

show more ...

[AST] Add a new TemplateKind for template decls found via a using decl.

This is the template version of https://reviews.llvm.org/D114251.

This patch introduces a new template name kind (UsingTempla

[AST] Add a new TemplateKind for template decls found via a using decl.

This is the template version of https://reviews.llvm.org/D114251.

This patch introduces a new template name kind (UsingTemplateName). The
UsingTemplateName stores the found using-shadow decl (and underlying
template can be retrieved from the using-shadow decl). With the new
template name, we can be able to find the using decl that a template
typeloc (e.g. TemplateSpecializationTypeLoc) found its underlying template,
which is useful for tooling use cases (include cleaner etc).

This patch merely focuses on adding the node to the AST.

Next steps:
- support using-decl in qualified template name;
- update the clangd and other tools to use this new node;
- add ast matchers for matching different kinds of template names;

Differential Revision: https://reviews.llvm.org/D123127

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An expression should only contain an unexpanded parameter pack if it
lexically contains a mention of the pack.

Systematically distinguish between syntactic and semantic references to
packs, especial

An expression should only contain an unexpanded parameter pack if it
lexically contains a mention of the pack.

Systematically distinguish between syntactic and semantic references to
packs, especially when propagating dependence from a type into an
expression. We should consult the type-as-written when computing
syntactic dependence and should consult the semantic type when computing
semantic dependence.

Fixes #54402.

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Revert "[clang] roll-forward "[clang] Mark `trivial_abi` types as "trivially relocatable""."

This reverts commit 56d46b36fc231a0beb518602503035bba92043e0.

The LIT test SemaCXX/attr-trivial-abi.cpp

Revert "[clang] roll-forward "[clang] Mark `trivial_abi` types as "trivially relocatable""."

This reverts commit 56d46b36fc231a0beb518602503035bba92043e0.

The LIT test SemaCXX/attr-trivial-abi.cpp is failing with 32bit build on
Windows. All the lines with the ifdef WIN32 are asserting but they are
not expected to. It looks like the LIT test was not tested on a 32bit
build of the compiler.

show more ...

[clang][SVE] Add support for bitwise operators on SVE types

This patch implements support for the &, |, ^, and ~ operators on sizeless SVE
types.

Differential Revision: https://reviews.llvm.org/D12

[clang][SVE] Add support for bitwise operators on SVE types

This patch implements support for the &, |, ^, and ~ operators on sizeless SVE
types.

Differential Revision: https://reviews.llvm.org/D121119

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let EST_Uninstantiated in FunctionProtoType::canThrow return
CT_Dependent

When compile following code without -std=c++17, clang will abort by
llvm_unreachable:

class A {
public:

static const c

let EST_Uninstantiated in FunctionProtoType::canThrow return
CT_Dependent

When compile following code without -std=c++17, clang will abort by
llvm_unreachable:

class A {
public:

static const char X;

};
const char A::X = 0;

template<typename U> void func() noexcept(U::X);

template<class... B, char x>
void foo(void(B...) noexcept(x)) {}

void bar()
{

foo(func<A>);

}

So, my solution is to let EST_Uninstantiated in
FunctionProtoType::canThrow return CT_Dependent

Differential Revision: https://reviews.llvm.org/D121498

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[clang][SVE] Add support for arithmetic operators on SVE types

This patch implements support for the +, -, *, / and % operators on sizeless SVE
types. Support for these operators on svbool_t is excl

[clang][SVE] Add support for arithmetic operators on SVE types

This patch implements support for the +, -, *, / and % operators on sizeless SVE
types. Support for these operators on svbool_t is excluded.

Differential Revision: https://reviews.llvm.org/D120323

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[clang] roll-forward "[clang] Mark `trivial_abi` types as "trivially relocatable"".

This reverts commit 852afed5e0200b70047c28ccf4424a17089d17b0.

Changes since D114732:

On PS4, we reverse the expe

[clang] roll-forward "[clang] Mark `trivial_abi` types as "trivially relocatable"".

This reverts commit 852afed5e0200b70047c28ccf4424a17089d17b0.

Changes since D114732:

On PS4, we reverse the expectation that classes whose constructor is deleted are not trivially relocatable. Because, at the moment, only classes which are passed in registers are trivially relocatable, and PS4 allows passing in registers if the copy constructor is deleted, the original assertions were broken on PS4.

(This is kinda similar to DR1734.)

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D119017

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Revert "[clang] Mark `trivial_abi` types as "trivially relocatable"."

This reverts commit 19aa2db023c0128913da223d4fb02c474541ee22. It breaks
a PS4 buildbot.

[clang] Mark `trivial_abi` types as "trivially relocatable".

This change enables library code to skip paired move-construction and destruction for `trivial_abi` types, as if they were trivially-mova

[clang] Mark `trivial_abi` types as "trivially relocatable".

This change enables library code to skip paired move-construction and destruction for `trivial_abi` types, as if they were trivially-movable and trivially-destructible. This offers an extension to the performance fix offered by `trivial_abi`: rather than only offering trivial-type-like performance for pass-by-value, it also offers it for library code that moves values but not as arguments.

For example, if we use `memcpy` for trivially relocatable types inside of vector reallocation, and mark `unique_ptr` as `trivial_abi` (via `_LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI` / `_LIBCPP_ABI_UNSTABLE` / etc.), this would speed up `vector<unique_ptr>::push_back` by 40% on my benchmarks. (Though note that in this case, the compiler could have done this anyway, but happens not to due to the inlining horizon.)

If accepted, I intend to follow up with exactly such changes to library code, including and especially `std::vector`, making them use a trivial relocation operation on trivially relocatable types.

**D50119 and P1144:**

This change is very similar to D50119, which was rejected from Clang. (That change was an implementation of P1144, which is not yet part of the C++ standard.)

The intent of this change, rather than trying to pick a winning proposal for trivial relocation operations, is to extend the behavior of `trivial_abi` in a way that could be made compatible with any such proposal. If P1144 or any similar proposal were accepted, then `trivial_abi`, `__is_trivially_relocatable`, and everything else in this change would be redefined in terms of that.

**Safety:**

It's worth pointing out, specifically, that `trivial_abi` already implies trivial relocatability in a narrow sense: a `trivial_abi` type, when passed by value, has its constructor run in one location, and its destructor run in another, after the type has been trivially relocated (through registers).

Trivial relocatability optimizations could change the number of paired constructor/destructor calls, but this seems unlikely to matter for `trivial_abi` types.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D114732

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[clang] Use nullptr instead of 0 or NULL (NFC)

Identified with modernize-use-nullptr.

Reland "[AST] Add UsingType: a sugar type for types found via UsingDecl"

This reverts commit cc56c66f27e131b914082d3bd21180646e842e9a.
Fixed a bad assertion, the target of a UsingShadowDecl must not

Reland "[AST] Add UsingType: a sugar type for types found via UsingDecl"

This reverts commit cc56c66f27e131b914082d3bd21180646e842e9a.
Fixed a bad assertion, the target of a UsingShadowDecl must not have
*local* qualifiers, but it can be a typedef whose underlying type is qualified.

show more ...

Revert "[AST] Add UsingType: a sugar type for types found via UsingDecl"

This reverts commit e1600db19d6303f84b995acb9340459694e06ea9.

Breaks sanitizer tests, at least on windows:
https://lab.llvm.

Revert "[AST] Add UsingType: a sugar type for types found via UsingDecl"

This reverts commit e1600db19d6303f84b995acb9340459694e06ea9.

Breaks sanitizer tests, at least on windows:
https://lab.llvm.org/buildbot/#/builders/127/builds/21592/steps/4/logs/stdio

show more ...

[AST] Add UsingType: a sugar type for types found via UsingDecl

Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl(

[AST] Add UsingType: a sugar type for types found via UsingDecl

Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl().

Design decisions:
- a sugar type, as there are many contexts this type of use may appear in
- UsingType is a leaf like TypedefType, the underlying type has no TypeLoc
- not unified with UnresolvedUsingType: a single name is appealing,
but being sometimes-sugar is often fiddly.
- not unified with TypedefType: the UsingShadowDecl is not a TypedefNameDecl or
even a TypeDecl, and users think of these differently.
- does not cover other rarer aliases like objc @compatibility_alias,
in order to be have a concrete API that's easy to understand.
- implicitly desugared by the hasDeclaration ASTMatcher, to avoid
breaking existing patterns and following the precedent of ElaboratedType.

Scope:
- This does not cover types associated with template names introduced by
using declarations. A future patch should introduce a sugar TemplateName
variant for this. (CTAD deduced types fall under this)
- There are enough AST matchers to fix the in-tree clang-tidy tests and
probably any other matchers, though more may be useful later.

Caveats:
- This changes a fairly common pattern in the AST people may depend on matching.
Previously, typeLoc(loc(recordType())) matched whether a struct was
referred to by its original scope or introduced via using-decl.
Now, the using-decl case is not matched, and needs a separate matcher.
This is similar to the case of typedefs but nevertheless both adds
complexity and breaks existing code.

Differential Revision: https://reviews.llvm.org/D114251

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Introduce _BitInt, deprecate _ExtInt

WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitI

Introduce _BitInt, deprecate _ExtInt

WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:

* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.

I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.

show more ...

[clang] retain type sugar in auto / template argument deduction

This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses th

[clang] retain type sugar in auto / template argument deduction

This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

Signed-off-by: Matheus Izvekov <[email protected]>

Reviewed By: rsmith, #libc, ldionne

Differential Revision: https://reviews.llvm.org/D110216

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