843 Commits

Author SHA1 Message Date
Richard Sandiford
33ee5c4663 [clang] Add Parse and Sema support for RegularKeyword attributes
This patch adds the Parse and Sema support for RegularKeyword attributes,
following on from a previous patch that added Attr.td support.

The patch is quite large.  However, nothing outside the tests is
specific to the first RegularKeyword attribute (__arm_streaming).
The patch should therefore be a one-off, up-front cost.  Other
attributes just need an entry in Attr.td and the usual Sema support.

The approach taken in the patch is that the keywords can be used with
any language version.  If standard attributes were added in language
version Y, the keyword rules for version X<Y are the same as they were
for version Y (to the extent possible).  Any extensions beyond Y are
handled in the same way for both keywords and attributes.  This ensures
that existing C++11 successors like C++17 are not treated differently
from versions that have yet to be defined.

Some notes on the implementation:

* The patch emits errors rather than warnings for diagnostics that
relate to keywords.

* Where possible, the patch drops “attribute” from diagnostics
relating to keywords.

* One exception to the previous point is that warnings about C++
extensions do still mention attributes.  The use there seemed OK
since the diagnostics are noting a change in the production rules.

* If a diagnostic string needs to be different for keywords and
attributes, the patch standardizes on passing the attribute/
name/token followed by 0 for attributes and 1 for keywords.

* Although the patch updates warn_attribute_wrong_decl_type_str,
warn_attribute_wrong_decl_type, and warn_attribute_wrong_decl_type,
only the error forms of these strings are used for keywords.

* I couldn't trigger the warnings in checkUnusedDeclAttributes,
even for existing attributes.  An assert on the warnings caused
no failures in the testsuite.  I think in practice all standard
attributes would be diagnosed before this.

* The patch drops a call to standardAttributesAllowed in
ParseFunctionDeclarator.  This is because MaybeParseCXX11Attributes
checks the same thing itself, where appropriate.

* The new tests are based on c2x-attributes.c and
cxx0x-attributes.cpp.  The C++ test also incorporates a version of
cxx11-base-spec-attributes.cpp.  The FIXMEs are carried across from
the originals.

Differential Revision: https://reviews.llvm.org/D148702
2023-05-31 10:43:10 +01:00
Jianjian GUAN
35a0079238 [RISCV] Add Zvfhmin extension for clang.
This patch adds the Zvfhmin extension for clang.

Reviewed By: craig.topper, michaelmaitland

Differential Revision: https://reviews.llvm.org/D150253
2023-05-31 14:31:11 +08:00
ziqingluo-90
6d861d498d [-Wunsafe-buffer-usage] Move the whole analysis to the end of a translation unit
The unsafe-buffer analysis requires a complete view of the translation
unit (TU) to be conservative. So the analysis is moved to the end of a
TU.

A summary of changes made: add a new `IssueWarnings` function in
`AnalysisBasedWarnings.cpp` for TU-based analyses. So far
[-Wunsafe-buffer-usage] is the only analysis using it but there could
be more.  `Sema` will call the new `IssueWarnings` function at the end
of parsing a TU.

Reviewed by: NoQ (Artem Dergachev)

Differential revision: https://reviews.llvm.org/D146342
2023-05-12 11:50:51 -07:00
Corentin Jabot
a7579b25df [Clang] Improve compile times when forming a DeclRef outside of a capturing scope.
The logic of whether an entity needs to be captured has become
quite complex and the recent changes in https://reviews.llvm.org/D124351
ad a mesurable negative impact on compile times.

However, in the absence of capturing scopes (lambda, block, region)
we usually can avoid running most of that logic
(except that we do need to diagnostic when a nested function
refers to a local variable in the scope of the outer function.).

This patch track whether there is currently an active capturing
scope and exit `tryCaptureVariable` early when there isn't.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D150038
2023-05-08 18:41:24 +02:00
Mark de Wever
ba15d186e5 [clang] Use -std=c++23 instead of -std=c++2b
During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.

This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.

Drive-by fixes c++1z -> c++17 and c++2a -> c++20 when seen.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D149553
2023-05-04 19:19:52 +02:00
David Stone
6d6880554c [clang][Sema][NFC] Move EnterExpressionEvaluationContext to its own file
Sema.h is huge. This makes a small reduction to it by moving
EnterExpressionEvaluationContext into a new header, since it is an
independent component.

Differential Revision: https://reviews.llvm.org/D149796
2023-05-04 13:06:53 -04:00
Stoorx
40136ecefc [clang] Make access to submodules via iterator_range
In file `clang/lib/Basic/Module.cpp` the `Module` class had `submodule_begin()` and `submodule_end()` functions to retrieve corresponding iterators for private vector of Modules. This commit removes mentioned functions, and replaces all of theirs usages with `submodules()` function and range-based for-loops.

Differential Revision: https://reviews.llvm.org/D148954
2023-04-24 12:05:59 +03:00
Timm Bäder
80fda7a346 [clang][Sema][NFC] Make a bunch of things const if possible
And some general code style cleanup.

Differential Revision: https://reviews.llvm.org/D148696
2023-04-20 12:23:51 +02:00
Timm Bäder
30aea03202 [clang][Sema][NFC] Use existing TargetInfo local variable 2023-04-20 11:25:46 +02:00
Manna, Soumi
18a3d9e5b3 [NFC][clang] Fix coverity static analyzer concerns about AUTO_CAUSES_COPY
Reported by Coverity:

AUTO_CAUSES_COPY
Unnecessary object copies can affect performance.

1. [NFC] Fix auto keyword use without an & causes the copy of an object of type SimpleRegistryEntry in clang::getAttributePluginInstances()

2. [NFC] Fix auto keyword use without an & causes the copy of an object of type tuple in CheckStmtInlineAttr<clang::NoInlineAttr, 2>(clang::Sema &, clang::Stmt const *, clang::Stmt const *, clang::AttributeCommonInfo const &)

3. [NFC] Fix auto keyword use without an & causes the copy of an object of type QualType in <unnamed>::SystemZTargetCodeGenInfo::isVectorTypeBased(clang::Type const *, bool)

4. [NFC] Fix auto keyword use without an & causes the copy of an object of type Policy in <unnamed>::RISCVIntrinsicManagerImpl::InitIntrinsicList()

5. [NFC] Fix auto keyword use without an & causes the copy of an object of type pair in checkUndefinedButUsed(clang::Sema &)

Reviewed By: tahonermann

Differential Revision: <https://reviews.llvm.org/D147543>
2023-04-17 21:33:21 -04:00
Corentin Jabot
43575719d0 [Clang] Fix crash caused by line splicing in doc comment
Because the comment parser does not support slices,
we emit a warning for comments that do contain
a splice within their delimiter, and do not add them as
documentation comment.

Fixes #62054

Reviewed By: shafik, aaron.ballman

Differential Revision: https://reviews.llvm.org/D148029
2023-04-12 10:07:51 +02:00
Timm Bäder
6603c68302 [clang][sema][NFC] Make a few functions const
Differential Revision: https://reviews.llvm.org/D145947
2023-03-14 13:48:11 +01:00
Chuanqi Xu
bf52ead24c [C++20] [Modules] Support to export declarations in language linkage
Close https://github.com/llvm/llvm-project/issues/60405

See the discussion in the above link for the background.

What the patch does:
- Rename `Module::ModuleKind::GlobalModuleFragment` to
  `Module::ModuleKind::ExplicitGlobalModuleFragment`.
- Add another module kind `ImplicitGlobalModuleFragment` to
  `ModuleKind`.
- Create an implicit global module fragment for the language linkage
  declarations inside a module purview.
    - If the language linkage lives inside the scope of an export decl,
      the created modules is marked as exported to outer modules.
- In fact, Sema will only create at most 2 implicit global module
  fragments to avoid creating a lot of unnecessary modules in the edging
case.

Reviewed By: iains

Differential Revision: https://reviews.llvm.org/D144367
2023-03-03 10:31:48 +08:00
Corentin Jabot
93d7002dc4 [Clang] Implement Change scope of lambda trailing-return-type
This implements P2036R3 and P2579R0.
That is, explicit, int, and implicit capture become visible
at the start of the parameter head.

Reviewed By: aaron.ballman, rupprecht, shafik

Differential Revision: https://reviews.llvm.org/D124351
2023-03-02 10:04:16 +01:00
Chuanqi Xu
55900a0d20 Recommit [Coroutines] Stop supportting std::experimental::coroutine_traits
As we discussed before, we should stop supporting
std::experimental::coroutine_traits in clang17. Now the clang16 is
branched so we can clean them now.

All the removed tests have been duplicated before.
2023-02-20 10:27:02 +08:00
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
Chuanqi Xu
6d5ea6b123 Revert "[Coroutines] Stop supportting std::experimental::coroutine_traits"
This reverts commit c4e6e771f255fb1da3d505534997b6a88195b012.

Since clang-tools-extra contains the use for
std::experimental::coroutine_traits, the previsou commit breaks the
build bot. Revert this one to make the bot green.
2023-02-17 15:50:54 +08:00
Chuanqi Xu
c4e6e771f2 [Coroutines] Stop supportting std::experimental::coroutine_traits
As we discussed before, we should stop supporting
std::experimental::coroutine_traits in clang17. Now the clang16 is
branched so we can clean them now.

All the removed tests have been duplicated before.
2023-02-17 15:35:17 +08:00
Chuanqi Xu
999ead9dc9 [Modules] Code cleanup after removing ModulesTS
Some codes become unused after we remove ModulesTS.
2023-02-16 15:22:38 +08:00
Chuanqi Xu
612f3ac26f [Modules] Remove -fmodules-ts
As the diagnostic message shows, we should remove -fmodules-ts flag in
clang/llvm17. Since clang/llvm16 is already branched. We can remove the
depreacared flag now.
2023-02-16 14:40:32 +08:00
eopXD
6e794ba0b2 [Clang][RISCV] Guard vector int64, float32, float64 with semantic analysis
Depends on D143657

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D143665
2023-02-14 17:38:25 -08:00
eopXD
235e90c1d7 [Clang][RISCV] Guard vector float16 type correctly with semantic analysis
Before this commit, vector float 16 types (e.g. `vfloat16m1_t`) of RVV
is only defined when extension `zvfh` is defined. However this
generate inaccurate diagnostics like:

```
error: unknown type name 'vfloat16m1_t'
```

This commit improves the compiler by guarding type check correctly
under semantic analysis.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D143657
2023-02-13 18:07:00 -08:00
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
Jordan Rupprecht
74ce297045 Revert "[Clang] Implement Change scope of lambda trailing-return-type"
This reverts commit d708a186b6a9b050d09558163dd353d9f738c82d (and typo fix e4bc9898ddbeb70bc49d713bbf863f050f21e03f). It causes a compilation error for this:

```
struct StringLiteral {
  template <int N>
  StringLiteral(const char (&array)[N])
      __attribute__((enable_if(N > 0 && N == __builtin_strlen(array) + 1,
                               "invalid string literal")));
};

struct Message {
  Message(StringLiteral);
};

void Func1() {
  auto x = Message("x");  // Note: this is fine

  // Note: "xx\0" to force a different type, StringLiteral<3>, otherwise this
  // successfully builds.
  auto y = [&](decltype(Message("xx"))) {};

  // ^ fails with: repro.cc:18:13: error: reference to local variable 'array'
  // declared in enclosing function 'StringLiteral::StringLiteral<3>'

  (void)x;
  (void)y;
}
```

More details posted to D124351.
2023-02-03 08:49:34 -08:00
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
Corentin Jabot
d708a186b6 [Clang] Implement Change scope of lambda trailing-return-type
This implements P2036R3 and P2579R0.
That is, explicit, int, and implicit capture become visible
at the start of the parameter head.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D124351
2023-01-31 11:06:14 +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
David Green
753aca0a3a [AArch64] Add an error if SVE scalable vector types are used in a context without sve
This adds an error message if the isSVESizelessBuiltinType like
__SVFloat32_t / __SVInt64_t / etc, which provide the backing for the
svfloat32_t / svint64_t / etc ACLE types, are used in a function without
SVE. The alternative is a crash in the backend, which is not capable of
handling scalable vector types.

When SVE is available, either through a -march=..+sve option or via a
target(sve) attribute, nothing should change. Without the sve feature,
this patch gives an error for any function arguments, return values and
variable declarations involving the scalable types. Struct/class members
and global variables already give an error. As this can be based on the
current function target attributes, the error sometimes needs to be
handled later than would otherwise if it was just based on the global
target.

Differential Revision: https://reviews.llvm.org/D131058
2023-01-12 18:21:28 +00:00
Pavel Iliin
fe5cf480ee Reland "[AArch64] FMV support and necessary target features dependencies."
This relands commits e43924a75145d2f9e722f74b673145c3e62bfd07,
a43f36142c501e2d3f4797ef938db4e0c5e0eeec,
bf94eac6a3f7c5cd8941956d44c15524fa3751bd with MSan buildbot
https://lab.llvm.org/buildbot/#/builders/5/builds/30139
use-of-uninitialized-value errors fixed.

Differential Revision: https://reviews.llvm.org/D127812
2022-12-27 19:18:07 +00:00
Mitch Phillips
744486ec21 Revert "[AArch64] FMV support and necessary target features dependencies."
This reverts commit e43924a75145d2f9e722f74b673145c3e62bfd07.

Reason: Patch broke the MSan buildbots. More information is available on
the original phabricator review: https://reviews.llvm.org/D127812
2022-12-20 17:16:32 -08:00
Pavel Iliin
e43924a751 [AArch64] FMV support and necessary target features dependencies.
This is Function Multi Versioning (FMV) implementation for AArch64 target in
accordance with Beta Arm C Language Extensions specification
https://github.com/ARM-software/acle/blob/main/main/acle.md#function-multi-versioning
It supports new "target_version" function attribute and extends existing
"target_clones" one. Also missing dependencies for target features were added.

Differential Revision: https://reviews.llvm.org/D127812
2022-12-20 15:42:25 +00:00
Dani Ferreira Franco Moura
0da4cecfb6 [clang][dataflow] Remove unused argument in getNullability
This change will allow users to call getNullability() without providing an ASTContext.

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D140104
2022-12-16 12:22:23 +01:00
Kazu Hirata
8595f2e54d [Sema] 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 11:13:39 -08:00
Jens Massberg
849b650cf3 [clang] Skip defaulted functions in zero-as-null-pointer-constant.
The zero-as-null-pointer-constant check should not fire if it is inside
a defaulted function, e.g. defaulted spaceship operators.
Add C++20 tests with spaceship operators.

Fixes #50221

Differential Revision: https://reviews.llvm.org/D138727
2022-11-29 11:56:10 +01:00
Matheus Izvekov
ee1f132d2c
Revert "[clang] ASTImporter: Fix importing of va_list types and declarations"
This reverts commit 5f820c0f55cd9d4f4520cc92eae0a1c4afe05a54.

Apparently it breaks aarch64 buildbots.
https://lab.llvm.org/buildbot#builders/188/builds/21591
2022-10-31 19:34:23 +01:00
Matheus Izvekov
5f820c0f55
[clang] ASTImporter: Fix importing of va_list types and declarations
This fixes a problem where __va_list_tag was not correctly imported,
possibly leading to multiple definitions with different types.

This adds __va_list_tag to it's proper scope, so that the ASTImporter
can find it.

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

Differential Revision: https://reviews.llvm.org/D136886
2022-10-31 17:57:18 +01:00
Nicolas Lesser
4848f3bf2f [C++2a] P0634r3: Down with typename!
This patch implements P0634r3 that removes the need for 'typename' in certain contexts.

For example,

```
template <typename T>
using foo = T::type; // ok
```

This is also allowed in previous language versions as an extension, because I think it's pretty useful. :)

Reviewed By: #clang-language-wg, erichkeane

Differential Revision: https://reviews.llvm.org/D53847
2022-09-28 09:50:19 -07:00
David Majnemer
955d7c39ff [clang] Add support for #pragma strict_gs_check 2022-09-19 20:07:14 +00:00
Sam McCall
897f3ddc61 [Sema] Move Diags.isIgnored() checks off hot paths, it's not free. NFC
This speeds up clangd's buildAST() (i.e. parsing with a preamble) by 5% on
clangd/AST.cpp, by avoiding filling up the diagnostic state map with entries for
all the files where templates are being instantiated from.

(I would assume it has a similar effect on PCH and modules compiles).

This approach is obviously pretty fragile, and we should find ways to make
isIgnored() cheaper instead. But these changes in particular don't seem to make
the code worse in any case.

Differential Revision: https://reviews.llvm.org/D129683
2022-09-07 16:18:31 +02:00
Kazu Hirata
b7a7aeee90 [clang] Qualify auto in range-based for loops (NFC) 2022-09-03 23:27:27 -07:00
Chris Bieneman
5b5329bd41 [NFC] Make MultiplexExternalSemaSource own sources
This change refactors the MuiltiplexExternalSemaSource to take ownership
of the underlying sources. As a result it makes a larger cleanup of
external source ownership in Sema and the ChainedIncludesSource.

Reviewed By: aaron.ballman, aprantl

Differential Revision: https://reviews.llvm.org/D133158
2022-09-02 13:57:39 -05:00
Iain Sandoe
fee3cccc6c [C++20][Modules] Improve handing of Private Module Fragment diagnostics.
This adds a check for exported inline functions, that there is a definition in
the definition domain (which, in practice, can only be the module purview but
before any PMF starts) since the PMF definition domain cannot contain exports.

This is:
[dcl.inline]/7
If an inline function or variable that is attached to a named module is declared in
a definition domain, it shall be defined in that domain.

The patch also amends diagnostic output by excluding the PMF sub-module from the
set considered as sources of missing decls.  There is no point in telling the user
that the import of a PMF object is missing - since such objects are never reachable
to an importer.  We still show the definition (as unreachable), to help point out
this.

Differential Revision: https://reviews.llvm.org/D128328
2022-08-21 10:19:46 +01:00
Chuanqi Xu
e8e46cdce3 [NFC] [C++20] [Modules] Use Sema::isCurrentModulePurview() to simplify the codes 2022-07-27 14:15:32 +08:00
Kito Cheng
7a5cb15ea6 [RISCV] Lazily add RVV C intrinsics.
Leverage the method OpenCL uses that adds C intrinsics when the lookup
failed. There is no need to define C intrinsics in the header file any
more. It could help to avoid the large header file to speed up the
compilation of RVV source code. Besides that, only the C intrinsics used
by the users will be added into the declaration table.

This patch is based on https://reviews.llvm.org/D103228 and inspired by
OpenCL implementation.

### Experimental Results

#### TL;DR:

- Binary size of clang increase ~200k, which is +0.07%  for debug build and +0.13% for release build.
- Single file compilation speed up ~33x for debug build and ~8.5x for release build
- Regression time reduce ~10% (`ninja check-all`, enable all targets)

#### Header size change
```
       |      size |     LoC |
------------------------------
Before | 4,434,725 |  69,749 |
After  |     6,140 |     162 |
```

#### Single File Compilation Time
Testcase:
```
#include <riscv_vector.h>

vint32m1_t test_vadd_vv_vfloat32m1_t(vint32m1_t op1, vint32m1_t op2, size_t vl) {
  return vadd(op1, op2, vl);
}
```
##### Debug build:
Before:
```
real    0m19.352s
user    0m19.252s
sys     0m0.092s
```

After:
```
real    0m0.576s
user    0m0.552s
sys     0m0.024s
```

~33x speed up for debug build

##### Release build:
Before:
```
real    0m0.773s
user    0m0.741s
sys     0m0.032s
```

After:
```
real    0m0.092s
user    0m0.080s
sys     0m0.012s
```

~8.5x speed up for release build

#### Regression time
Note: the failed case is `tools/llvm-debuginfod-find/debuginfod.test` which is unrelated to this patch.

##### Debug build
Before:
```
Testing Time: 1358.38s
  Skipped          :    11
  Unsupported      :   446
  Passed           : 75767
  Expectedly Failed:   190
  Failed           :     1
```
After
```
Testing Time: 1220.29s
  Skipped          :    11
  Unsupported      :   446
  Passed           : 75767
  Expectedly Failed:   190
  Failed           :     1
```
##### Release build
Before:
```
Testing Time: 381.98s
  Skipped          :    12
  Unsupported      :  1407
  Passed           : 74765
  Expectedly Failed:   176
  Failed           :     1
```
After:
```
Testing Time: 346.25s
  Skipped          :    12
  Unsupported      :  1407
  Passed           : 74765
  Expectedly Failed:   176
  Failed           :     1
```

#### Binary size of clang

##### Debug build
Before
```
   text    data     bss     dec     hex filename
335261851       12726004         552812 348540667       14c64efb        bin/clang
```
After
```
   text    data     bss     dec     hex filename
335442803       12798708         552940 348794451       14ca2e53        bin/clang
```
+253K, +0.07% code size

##### Release build
Before
```
   text    data     bss     dec     hex filename
144123975       8374648  483140 152981763       91e5103 bin/clang
```
After
```
   text    data     bss     dec     hex filename
144255762       8447296  483268 153186326       9217016 bin/clang
```
+204K, +0.13%

Authored-by: Kito Cheng <kito.cheng@sifive.com>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Reviewed By: khchen, aaron.ballman

Differential Revision: https://reviews.llvm.org/D111617
2022-07-26 15:47:47 +08:00
Kazu Hirata
3f3930a451 Remove redundaunt virtual specifiers (NFC)
Identified with tidy-modernize-use-override.
2022-07-25 23:00:59 -07:00
Serge Pavlov
f7819ce166 [FPEnv] Allow CompoundStmt to keep FP options
This is a recommit of b822efc7404bf09ccfdc1ab7657475026966c3b2,
reverted in dc34d8df4c48b3a8f474360970cae8a58e6c84f0. The commit caused
fails because the test ast-print-fp-pragmas.c did not specify particular
target, and it failed on targets which do not support constrained
intrinsics. The original commit message is below.

AST does not have special nodes for pragmas. Instead a pragma modifies
some state variables of Sema, which in turn results in modified
attributes of AST nodes. This technique applies to floating point
operations as well. Every AST node that can depend on FP options keeps
current set of them.

This technique works well for options like exception behavior or fast
math options. They represent instructions to the compiler how to modify
code generation for the affected nodes. However treatment of FP control
modes has problems with this technique. Modifying FP control mode
(like rounding direction) usually requires operations on hardware, like
writing to control registers. It must be done prior to the first
operation that depends on the control mode. In particular, such
operations are required for implementation of `pragma STDC FENV_ROUND`,
compiler should set up necessary rounding direction at the beginning of
compound statement where the pragma occurs. As there is no representation
for pragmas in AST, the code generation becomes a complicated task in
this case.

To solve this issue FP options are kept inside CompoundStmt. Unlike to FP
options in expressions, these does not affect any operation on FP values,
but only inform the codegen about the FP options that act in the body of
the statement. As all pragmas that modify FP environment may occurs only
at the start of compound statement or at global level, such solution
works for all relevant pragmas. The options are kept as a difference
from the options in the enclosing compound statement or default options,
it helps codegen to set only changed control modes.

Differential Revision: https://reviews.llvm.org/D123952
2022-07-03 17:06:26 +07:00
Serge Pavlov
dc34d8df4c Revert "[FPEnv] Allow CompoundStmt to keep FP options"
On some buildbots test `ast-print-fp-pragmas.c` fails, need to investigate it.

This reverts commit 0401fd12d4aa0553347fe34d666fb236d8719173.
This reverts commit b822efc7404bf09ccfdc1ab7657475026966c3b2.
2022-07-01 15:42:39 +07:00
Serge Pavlov
b822efc740 [FPEnv] Allow CompoundStmt to keep FP options
AST does not have special nodes for pragmas. Instead a pragma modifies
some state variables of Sema, which in turn results in modified
attributes of AST nodes. This technique applies to floating point
operations as well. Every AST node that can depend on FP options keeps
current set of them.

This technique works well for options like exception behavior or fast
math options. They represent instructions to the compiler how to modify
code generation for the affected nodes. However treatment of FP control
modes has problems with this technique. Modifying FP control mode
(like rounding direction) usually requires operations on hardware, like
writing to control registers. It must be done prior to the first
operation that depends on the control mode. In particular, such
operations are required for implementation of `pragma STDC FENV_ROUND`,
compiler should set up necessary rounding direction at the beginning of
compound statement where the pragma occurs. As there is no representation
for pragmas in AST, the code generation becomes a complicated task in
this case.

To solve this issue FP options are kept inside CompoundStmt. Unlike to FP
options in expressions, these does not affect any operation on FP values,
but only inform the codegen about the FP options that act in the body of
the statement. As all pragmas that modify FP environment may occurs only
at the start of compound statement or at global level, such solution
works for all relevant pragmas. The options are kept as a difference
from the options in the enclosing compound statement or default options,
it helps codegen to set only changed control modes.

Differential Revision: https://reviews.llvm.org/D123952
2022-07-01 14:32:33 +07:00