536 Commits

Author SHA1 Message Date
Sander de Smalen
07158c54ad [Clang] Create opaque type for AArch64 SVE2p1/SME2 svcount_t.
This patch adds the builtin type __SVCount_t to Clang, which is an opaque
scalable type defined in the SME2 C and C++ Language Extensions.

The type maps to the `target("aarch64.svcount")` LLVM IR type.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D136864
2023-03-07 14:43:50 +00:00
Paulo Matos
890146b192 [WebAssembly] Initial support for reference type externref in clang
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D122215
2023-02-17 18:48:48 -08:00
Ramon de C Valle
71c7313f42 Add CFI integer types normalization
This commit adds a new option (i.e.,
`-fsanitize-cfi-icall-normalize-integers`) for normalizing integer types
as vendor extended types for cross-language LLVM CFI/KCFI support with
other languages that can't represent and encode C/C++ integer types.

Specifically, integer types are encoded as their defined representations
(e.g., 8-bit signed integer, 16-bit signed integer, 32-bit signed
integer, ...) for compatibility with languages that define
explicitly-sized integer types (e.g., i8, i16, i32, ..., in Rust).

``-fsanitize-cfi-icall-normalize-integers`` is compatible with
``-fsanitize-cfi-icall-generalize-pointers``.

This helps with providing cross-language CFI support with the Rust
compiler and is an alternative solution for the issue described and
alternatives proposed in the RFC
https://github.com/rust-lang/rfcs/pull/3296.

For more information about LLVM CFI/KCFI and cross-language LLVM
CFI/KCFI support for the Rust compiler, see the design document in the
tracking issue https://github.com/rust-lang/rust/issues/89653.

Relands b1e9ab7438a098a18fecda88fc87ef4ccadfcf1e with fixes.

Reviewed By: pcc, samitolvanen

Differential Revision: https://reviews.llvm.org/D139395
2023-02-08 22:24:19 +00:00
Vitaly Buka
bccf5999d3 Revert "[clang][WebAssembly] Initial support for reference type externref in clang"
Very likely breaks stage 3 of msan build bot.
Good: 764c88a50ac76a2df2d051a0eb5badc6867aabb6 https://lab.llvm.org/buildbot/#/builders/74/builds/17058
Looks unrelated: 48b5a06dfcab12cf093a1a3df42cb5b684e2be4c
Bad: 48b5a06dfcab12cf093a1a3df42cb5b684e2be4c https://lab.llvm.org/buildbot/#/builders/74/builds/17059

This reverts commit eb66833d19573df97034a81279eda31b8d19815b.
2023-02-05 21:41:48 -08:00
Mitch Phillips
b88ebb3d94 Revert "Add CFI integer types normalization"
This reverts commit b1e9ab7438a098a18fecda88fc87ef4ccadfcf1e.

Reason: Looks like it broke the MSan buildbot, more details in the
phabricator review: https://reviews.llvm.org/D139395
2023-02-02 15:48:50 -08:00
Ramon de C Valle
b1e9ab7438 Add CFI integer types normalization
This commit adds a new option (i.e.,
`-fsanitize-cfi-icall-normalize-integers`) for normalizing integer types
as vendor extended types for cross-language LLVM CFI/KCFI support with
other languages that can't represent and encode C/C++ integer types.

Specifically, integer types are encoded as their defined representations
(e.g., 8-bit signed integer, 16-bit signed integer, 32-bit signed
integer, ...) for compatibility with languages that define
explicitly-sized integer types (e.g., i8, i16, i32, ..., in Rust).

``-fsanitize-cfi-icall-normalize-integers`` is compatible with
``-fsanitize-cfi-icall-generalize-pointers``.

This helps with providing cross-language CFI support with the Rust
compiler and is an alternative solution for the issue described and
alternatives proposed in the RFC
https://github.com/rust-lang/rfcs/pull/3296.

For more information about LLVM CFI/KCFI and cross-language LLVM
CFI/KCFI support for the Rust compiler, see the design document in the
tracking issue https://github.com/rust-lang/rust/issues/89653.

Reviewed By: pcc, samitolvanen

Differential Revision: https://reviews.llvm.org/D139395
2023-02-01 17:48:03 +00:00
Paulo Matos
eb66833d19 [clang][WebAssembly] Initial support for reference type externref in clang
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.

Differential Revision: https://reviews.llvm.org/D122215
2023-01-31 17:34:01 +01:00
Elizabeth Andrews
f81d529f89 [Clang] Fix compilation errors for unsupported __bf16 intrinsics
This patch uses existing deferred diagnostics framework to emit error
for unsupported type __bf16 in device code. Error is not emitted in
host code.

Differential Revision: https://reviews.llvm.org/D141375
2023-01-25 12:43:36 -08:00
Kazu Hirata
6ad0788c33 [clang] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 12:31:01 -08:00
Kazu Hirata
a1580d7b59 [clang] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 11:07:21 -08:00
Alan Zhao
95a4c0c835 [clang] Reland parenthesized aggregate init patches
This commit relands the patches for implementing P0960R3 and P1975R0,
which describe initializing aggregates via a parenthesized list.

The relanded commits are:

* 40c52159d3ee - P0960R3 and P1975R0: Allow initializing aggregates from
  a parenthesized list of values
* c77a91bb7ba7 - Remove overly restrictive aggregate paren init logic
* 32d7aae04fdb - Fix a clang crash on invalid code in C++20 mode

This patch also fixes a crash in the original implementation.
Previously, if the input tried to call an implicitly deleted copy or
move constructor of a union, we would then try to initialize the union
by initializing it's first element with a reference to a union. This
behavior is incorrect (we should fail to initialize) and if the type of
the first element has a constructor with a single template typename
parameter, then Clang will explode. This patch fixes that issue by
checking that constructor overload resolution did not result in a
deleted function before attempting parenthesized aggregate
initialization.

Additionally, this patch also includes D140159, which contains some
minor fixes made in response to code review comments in the original
implementation that were made after that patch was submitted.

Co-authored-by: Sheng <ox59616e@gmail.com>

Fixes #54040, Fixes #59675

Reviewed By: ilya-biryukov

Differential Revision: https://reviews.llvm.org/D141546
2023-01-12 09:58:15 -08:00
Alan Zhao
4e02ff2303 [clang] Revert parentesized aggregate initalization patches
This feature causes clang to crash when compiling Chrome - see
https://crbug.com/1405031 and
https://github.com/llvm/llvm-project/issues/59675

Revert "[clang] Fix a clang crash on invalid code in C++20 mode."

This reverts commit 32d7aae04fdb58e65a952f281ff2f2c3f396d98f.

Revert "[clang] Remove overly restrictive aggregate paren init logic"

This reverts commit c77a91bb7ba793ec3a6a5da3743ed55056291658.

Revert "[clang][C++20] P0960R3 and P1975R0: Allow initializing aggregates from a parenthesized list of values"

This reverts commit 40c52159d3ee337dbed14e4c73b5616ea354c337.
2023-01-04 15:09:36 -08:00
Alan Zhao
40c52159d3 [clang][C++20] P0960R3 and P1975R0: Allow initializing aggregates from a parenthesized list of values
This patch implements P0960R3, which allows initialization of aggregates
via parentheses.

As an example:

```
struct S { int i, j; };
S s1(1, 1);

int arr1[2](1, 2);
```

This patch also implements P1975R0, which fixes the wording of P0960R3
for single-argument parenthesized lists so that statements like the
following are allowed:

```
S s2(1);
S s3 = static_cast<S>(1);
S s4 = (S)1;

int (&&arr2)[] = static_cast<int[]>(1);
int (&&arr3)[2] = static_cast<int[2]>(1);
```

This patch was originally authored by @0x59616e and completed by
@ayzhao.

Fixes #54040, Fixes #54041

Co-authored-by: Sheng <ox59616e@gmail.com>

Full write up : https://discourse.llvm.org/t/c-20-rfc-suggestion-desired-regarding-the-implementation-of-p0960r3/63744

Reviewed By: ilya-biryukov

Differential Revision: https://reviews.llvm.org/D129531
2022-12-14 07:54:15 -08:00
Kazu Hirata
e31564afc3 [AST] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-03 11:13:41 -08:00
Nathan James
15e76eed0c
[clang] Add [is|set]Nested methods to NamespaceDecl
Adds support for NamespaceDecl to inform if its part of a nested namespace.
This flag only corresponds to the inner namespaces in a nested namespace declaration.
In this example:
namespace <X>::<Y>::<Z> {}
Only <Y> and <Z> will be classified as nested.

This flag isn't meant for assisting in building the AST, more for static analysis and refactorings.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D90568
2022-11-24 12:44:35 +00:00
Eli Friedman
0fcb26c5b6 [clang] Fix __try/__finally blocks in C++ constructors.
We were crashing trying to convert a GlobalDecl from a
CXXConstructorDecl.  Instead of trying to do that conversion, just pass
down the original GlobalDecl.

I think we could actually compute the correct constructor/destructor
kind from the context, given the way Microsoft mangling works, but it's
simpler to just pass through the correct constructor/destructor kind.

Differential Revision: https://reviews.llvm.org/D136776
2022-11-16 15:13:33 -08:00
Matheus Izvekov
1acffe81ee
NFC: [clang] Template argument cleanups.
Removes a bunch of obsolete methods in favor of a single one returning
an ArrayRef of TemplateArgument.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D136602
2022-10-25 00:29:56 +02:00
Rong Xu
6cee539337 [Clang] Change AnonStructIds in MangleContext to per-function based
Clang is generating different mangled names for the same lambda
function in slightly changed builds (like with non-related
source/Macro change). This is due to the fact that clang uses a
cross-translation-unit sequential string "$_<n>" in lambda's
mangled name. Here, "n" is the AnonStructIds field in MangleContext.

Different mangled names for a unchanged function is undesirable:
it makes perf comparison harder, and can cause some unnecessary
profile mismatch in SampleFDO.

This patch makes mangled name for lambda functions more stable
by changing AnonStructIds to a per-function based seq number if the
DeclContext is a function.

Differential Revision: https://reviews.llvm.org/D136397
2022-10-23 22:33:52 -07:00
Christopher Di Bella
e9ef45635b [clang] adds unary type transformations as compiler built-ins
Adds

* `__add_lvalue_reference`
* `__add_pointer`
* `__add_rvalue_reference`
* `__decay`
* `__make_signed`
* `__make_unsigned`
* `__remove_all_extents`
* `__remove_extent`
* `__remove_const`
* `__remove_volatile`
* `__remove_cv`
* `__remove_pointer`
* `__remove_reference`
* `__remove_cvref`

These are all compiler built-in equivalents of the unary type traits
found in [[meta.trans]][1]. The compiler already has all of the
information it needs to answer these transformations, so we can skip
needing to make partial specialisations in standard library
implementations (we already do this for a lot of the query traits). This
will hopefully improve compile times, as we won't need use as much
memory in such a base part of the standard library.

[1]: http://wg21.link/meta.trans

Co-authored-by: zoecarver

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D116203
2022-08-22 03:03:32 +00:00
Nico Weber
aacf1a9742 Revert "[clang] adds unary type transformations as compiler built-ins"
This reverts commit bc60cf2368de90918719dc7e3d7c63a72cc007ad.
Doesn't build on Windows and breaks gcc 9 build, see
https://reviews.llvm.org/D116203#3722094 and
https://reviews.llvm.org/D116203#3722128

Also revert two follow-ups. One fixed a warning added in
bc60cf2368de90918719dc7e3d7c63a72cc007ad, the other
makes use of the feature added in bc60cf2368de90918719dc7e3d7c63a72cc007ad
in libc++:

Revert "[libcxx][NFC] utilises compiler builtins for unary transform type-traits"
This reverts commit 06a1d917ef1f507aaa2f6891bb654696c866ea3a.

Revert "[Sema] Fix a warning"
This reverts commit c85abbe879ef3257de4db862ce249b060cc3d2a4.
2022-08-14 15:58:21 -04:00
Christopher Di Bella
bc60cf2368 [clang] adds unary type transformations as compiler built-ins
Adds

* `__add_lvalue_reference`
* `__add_pointer`
* `__add_rvalue_reference`
* `__decay`
* `__make_signed`
* `__make_unsigned`
* `__remove_all_extents`
* `__remove_extent`
* `__remove_const`
* `__remove_volatile`
* `__remove_cv`
* `__remove_pointer`
* `__remove_reference`
* `__remove_cvref`

These are all compiler built-in equivalents of the unary type traits
found in [[meta.trans]][1]. The compiler already has all of the
information it needs to answer these transformations, so we can skip
needing to make partial specialisations in standard library
implementations (we already do this for a lot of the query traits). This
will hopefully improve compile times, as we won't need use as much
memory in such a base part of the standard library.

[1]: http://wg21.link/meta.trans

Co-authored-by: zoecarver

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D116203
2022-08-14 17:12:15 +00:00
Fangrui Song
3f18f7c007 [clang] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D131346
2022-08-08 09:12:46 -07:00
Kazu Hirata
2e603c67c2 [clang] Construct SmallVector with iterator ranges (NFC) 2022-06-10 22:45:26 -07:00
Nathan Sidwell
a1dcfb75ea [clang] Module global init mangling
C++20 modules require emission of an initializer function, which is
called by importers of the module.  This implements the mangling for
that function.  It is the one place the ABI exposes partition names in
symbols -- but fortunately only needed by other TUs of that same module.

Reviewed By: bruno

Differential Revision: https://reviews.llvm.org/D122741
2022-05-23 09:03:10 -07:00
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
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
Yaxun (Sam) Liu
62501bc45a [NFC][CUDA][HIP] rework mangling number for aux target
CUDA/HIP needs to mangle for aux target. When mangling for aux target,
the mangler should use mangling number for aux target. Previously
in https://reviews.llvm.org/D122734 a state was introduced in
ASTContext to let the mangler get mangling number for aux target
from ASTContext. This patch removes that state from ASTConext
and add an IsAux member to MangleContext to indicate that
the mangle context is for aux target. This reflects the reality that
the mangle context is created for mangling aux target and makes
ASTContext cleaner.

Reviewed by: Artem Belevich, Reid Kleckner

Differential Revision: https://reviews.llvm.org/D124842
2022-05-04 13:05:33 -04:00
Harald van Dijk
fed7be096f
Mark identifier prefixes as substitutable
The Itanium C++ ABI says prefixes are substitutable. For most prefixes
we already handle this: the manglePrefix(const DeclContext *, bool) and
manglePrefix(QualType) overloads explicitly handles substitutions or
defer to functions that handle substitutions on their behalf. The
manglePrefix(NestedNameSpecifier *) overload, however, is different and
handles some cases implicitly, but not all. The Identifier case was not
handled; this change adds handling for it, as well as a test case.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D122663
2022-05-02 18:07:47 +01:00
Haojian Wu
864752cfeb [AST] QualifiedTemplateName::getTemplateDecl cleanup.
This is a followup cleanup of 1234b1c6d8113d50beef5801be607ad1d502b2f7

Differential Revision: https://reviews.llvm.org/D124238
2022-04-22 14:28:48 +02:00
Haojian Wu
6ba1b9075d 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
2022-04-14 11:04:55 +02:00
Haojian Wu
95f0f69f1f 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.
2022-04-12 11:51:00 +02:00
Haojian Wu
5a5be4044f [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
2022-04-12 10:48:23 +02:00
Erich Keane
d1205bb37d Reapply"[GH54588]Fix ItaniumMangler for NTTP unnamed unions w/ unnamed structs"
AND the followups that fixed builds.

I attempted to get 'cute' and use llvm-cxxfilt to make the test look
nicer, but apparently some of the bots have a version of llvm-cxxfilt
that is not the in-tree one, so it fails to properly demangle the stuff.
I've disabled this "RUN" line.

This reverts commit 50186b63d1807d389f31c515377d94185795ab44.
2022-04-04 06:41:47 -07:00
Nico Weber
50186b63d1 Revert "[GH54588]Fix ItaniumMangler for NTTP unnamed unions w/ unnamed structs"
This reverts commit 4cf98f973a13c5049322abff43f0dff3c214311b.
The test fails on mac bots, see comments on https://reviews.llvm.org/D122820

Also reverts follow-ups eb920989865d992093993143ba3c6e71126cbb89 and
861c189d2a5203ba8c8e983e8d2e109c0de153a5.
2022-04-03 17:21:27 -04:00
Erich Keane
4cf98f973a [GH54588]Fix ItaniumMangler for NTTP unnamed unions w/ unnamed structs
As reported in https://github.com/llvm/llvm-project/issues/54588
and discussed in https://github.com/itanium-cxx-abi/cxx-abi/issues/139

We are supposed to do a DFS, pre-order, decl-order search for a name for
the union in this case. Prevoiusly we crashed because the IdentiferInfo
pointer was nullptr, so this makes sure we have a name in the cases
described by the ABI.

I added an llvm-unreachable to cover an unexpected case at the end of
the new function with information/reference to the ABI in case we come
up with some way to get back to here.

Differential Revision: https://reviews.llvm.org/D122820
2022-04-01 11:31:14 -07:00
Nathan Sidwell
ae4dce8659 [clang][ABI] New C++20 module mangling scheme
Implement a demangleable strong ownership symbol mangling.

 * The original module symbol mangling scheme turned out to be
undemangleable.

 * The hoped-for C++17 compatibility of weak ownership turns out to be
fragile

* C++20 now has better ways of controlling C++17 compatibility

The issue is captured on the ABI list at:
  https://github.com/itanium-cxx-abi/cxx-abi/issues/134

GCC implements this new mangling.

The old mangling is unceremoniously dropped.  No backwards
compatibility, no deprectated old-mangling flag.  It was always
labelled experimental.  (Old and new manglings cannot be confused.)

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D122256
2022-03-30 08:51:27 -07:00
Yonghong Song
3251ba2d0f [Attr] Fix a btf_type_tag AST generation
Current ASTContext.getAttributedType() takes attribute kind,
ModifiedType and EquivType as the hash to decide whether an AST node
has been generated or note. But this is not enough for btf_type_tag
as the attribute might have the same ModifiedType and EquivType, but
still have different string associated with attribute.

For example, for a data structure like below,
  struct map_value {
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
        int __attribute__((btf_type_tag("tag2"))) __attribute__((btf_type_tag("tag4"))) *b;
  };
The current ASTContext.getAttributedType() will produce
an AST similar to below:
  struct map_value {
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *b;
  };
and this is incorrect.

It is very difficult to use the current AttributedType as it is hard to
get the tag information. To fix the problem, this patch introduced
BTFTagAttributedType which is similar to AttributedType
in many ways but with an additional BTFTypeTagAttr. The tag itself can
be retrieved with BTFTypeTagAttr.
With the new BTFTagAttributed type, the debuginfo code can be greatly
simplified compared to previous TypeLoc based approach.

Differential Revision: https://reviews.llvm.org/D120296
2022-03-16 08:46:52 -07:00
Chuanqi Xu
845f0bb5fa Revert "[clang][ABI] New C++20 module mangling scheme"
This reverts commit 21e16ab6b8ddaccb70d2344bb35419e214a32ec9.

It looks like it would break builds in mac. See
https://reviews.llvm.org/D118352.
2022-03-09 10:15:15 +08:00
Nathan Sidwell
21e16ab6b8 [clang][ABI] New C++20 module mangling scheme
The existing module symbol mangling scheme turns out to be
undemangleable.  It is also desirable to switch to the
strong-ownership model as the hoped-for C++17 compatibility turns out
to be fragile, and we also now have a better way of controlling that.

The issue is captured on the ABI list at:
  https://github.com/itanium-cxx-abi/cxx-abi/issues/134

A document describing the issues and new mangling is at:
  https://drive.google.com/file/d/1qQjqptzOFT_lfXH8L6-iD9nCRi34wjft/view

This patch is the code-generation part.  I have a demangler too, but
that patch is based on some to-be-landed refactoring of the demangler.

The old mangling is unceremoniously dropped.  No backwards
compatibility, no deprectated old-mangling flag.  It was always
labelled experimental.  (Old and new manglings cannot be confused.)

Reviewed By: ChuanqiXu

Differential Revision: https://reviews.llvm.org/D118352
2022-03-08 06:21:50 -08:00
Peter Collingbourne
82e5f951fd AST: Move __va_list tag back to std conditionally on AArch64.
In post-commit feedback on D104830 Jessica Clarke pointed out that
unconditionally adding __va_list to the std namespace caused namespace
debug info to be emitted in C, which is not only inappropriate but
turned out to confuse the dtrace tool. Therefore, move __va_list back
to std only in C++ so that the correct debug info is generated. We
also considered moving __va_list to the top level unconditionally
but this would contradict the specification and be visible to AST
matchers and such, so make it conditional on the language mode.

To avoid breaking name mangling for __va_list, teach the Itanium
name mangler to always mangle it as if it were in the std namespace
when targeting ARM architectures. This logic is not needed for the
Microsoft name mangler because Microsoft platforms define va_list as
a typedef of char *.

Depends on D116773

Differential Revision: https://reviews.llvm.org/D116774
2022-02-17 11:31:40 -08:00
Peter Collingbourne
18ead23385 AST: Make getEffectiveDeclContext() a member function of ItaniumMangleContextImpl. NFCI.
In an upcoming change we are going to need to access mangler state
from the getEffectiveDeclContext() function. Therefore, make it a
member function of ItaniumMangleContextImpl. Any callers that are
not currently members of ItaniumMangleContextImpl or CXXNameMangler
are made members of one or the other depending on where they are
called from.

Differential Revision: https://reviews.llvm.org/D116773
2022-02-17 11:31:40 -08:00
Nathan Sidwell
082f328899 [clang] Itanium mangler constructors
The Itanium mangler constructors use both NSDMI and explicit member
construction for default values.  This is confusing.

*) Use NSDMIs wherever possible

*) Use forwarding ctor for the nesting case with an
 llvm::raw_null_ostream (and explicitly set NullOut flag in that ctor).

*) Copy the ModuleSubstitutions.  This is a bug with no effect in the
 current mangling, but not in the newer mangling.

Reviewed By: ChuanqiXu

Differential Revision: https://reviews.llvm.org/D119550
2022-02-16 04:30:47 -08:00
Nathan Sidwell
02093906fa [clang][NFC] Remove IgnoreLinkageSpecDecls
The Itanium mangler uses IgnoreLinkageSpecDecls to strip linkage spec
contexts.  It doesn't do this consistently, but there is no need for
it to do it at all.  getEffectiveDeclContext never returns a linkage
spec, as it either recurses, uses getRedeclContext (which itself
removes the specs), or gets the decl context of non-namespace entities.

This patch removes the function and all calls to it.  For safety I add
a couple of asserts to make sure we never get them.

Reviewed By: ChuanqiXu

Differential Revision: https://reviews.llvm.org/D119748
2022-02-15 04:28:45 -08:00
Nathan Sidwell
815446cd3e [clang][NFC] Standard substitution checking cleanup
In preparing for module mangling changes I noticed some issues with
the way we check for std::basic_string instantiations and friends.

*) there's a single routine for std::basic_{i,o,io}stream but it is
 templatized on the length of the name.  Really?  just use a
 StringRef, rather than clone the entire routine just for
 'basic_iostream'.

*) We have a helper routine to check for char type, and call it from
 several places.  But given all the instantiations are of the form
 TPL<char, Other<char> ...> we could just check the first arg is char
 and the later templated args are instantiating that same type.  A
 simpler type comparison.

*) Because basic_string has a third allocator parameter, it is open
 coded, which I found a little confusing.  But otherwise it's exactly
 the same pattern as the iostream ones.  Just tell that checker about
 whether there's an expected allocator argument.[*]

*) We may as well return in each block of mangleStandardSubstitution
 once we determine it is not one of the entities of interest -- it
 certainly cannot be one of the other kinds of entities.

FWIW this shaves about 500 bytes off the executable.

[*] I suppose we could also have this routine a tri-value, with one to
indicat 'it is this name, but it's not the one you're looking for', to
avoid later calls trying different names?

Reviewd By: ChuanqiXu

Differential Revision: https://reviews.llvm.org/D119333
2022-02-10 04:44:48 -08:00
Nathan Sidwell
493c856484 [clang][NFC] Small mangler cleanups
In working on a module mangling problem I noticed a few cleanups to the mangler.

1) Use 'if (auto x = ...' idiom in a couple of places.

2) I noticed both 'isFileContext' and 'isNamespace || isTranslationUnit'
   synonyms. Let's use the former.

3) The control flow in the seqId mangling was misordered. Let's channel Count
   von Count. Also fix the inconsistent bracing.

Differential Revision: https://reviews.llvm.org/D117799
2022-01-20 11:20:15 -08:00
Sam McCall
af27466c50 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.
2021-12-20 18:03:15 +01:00
Sam McCall
cc56c66f27 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
2021-12-20 17:53:56 +01:00
Sam McCall
e1600db19d [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
2021-12-20 17:15:38 +01:00
Aaron Ballman
6c75ab5f66 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.
2021-12-06 12:52:01 -05:00
Quinn Pham
c71fbdd87b [NFC] Inclusive language: Remove instances of master in URLs
[NFC] This patch fixes URLs containing "master". Old URLs were either broken or
redirecting to the new URL.

Reviewed By: #libc, ldionne, mehdi_amini

Differential Revision: https://reviews.llvm.org/D113186
2021-11-05 08:48:41 -05:00