[clang] Use {} instead of std::nullopt to initialize empty ArrayRef (#109399)

Follow up to #109133.

[clang] Use StringRef::{starts,ends}_with (NFC) (#75149)

This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}:

[clang] Use StringRef::{starts,ends}_with (NFC) (#75149)

This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.

I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.

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[NFC] Fix static analyzer concern

Fix static analyzer concern about potential null value
dereference. findBackingIvar() dereferences Prop. PR
checks that Prop exists before calling the function.

Di

[NFC] Fix static analyzer concern

Fix static analyzer concern about potential null value
dereference. findBackingIvar() dereferences Prop. PR
checks that Prop exists before calling the function.

Differential Revision: https://reviews.llvm.org/D157429

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[Clang] Treat `std::forward_like` as builtin

This diff extends D123345 by adding support for std::forward_like.

Test plan: ninja check-clang check-clang-tools check-llvm

Differential revision: htt

[Clang] Treat `std::forward_like` as builtin

This diff extends D123345 by adding support for std::forward_like.

Test plan: ninja check-clang check-clang-tools check-llvm

Differential revision: https://reviews.llvm.org/D142430

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[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 p

[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

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[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::Option

[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

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llvm::Optional::value => operator*/operator->

std::optional::value() has undesired exception checking semantics and is
unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The

llvm::Optional::value => operator*/operator->

std::optional::value() has undesired exception checking semantics and is
unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The
call sites block std::optional migration.

This makes `ninja clang` work in the absence of llvm::Optional::value.

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[Analysis] 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 o

[Analysis] 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

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[clang] Use value instead of getValue (NFC)

[FPEnv] Allow CompoundStmt to keep FP options

This is a recommit of b822efc7404bf09ccfdc1ab7657475026966c3b2,
reverted in dc34d8df4c48b3a8f474360970cae8a58e6c84f0. The commit caused
fails because th

[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

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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.
T

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.

show more ...

[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

[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

show more ...

[clang] Don't use Optional::hasValue (NFC)

This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.

Revert "Don't use Optional::hasValue (NFC)"

This reverts commit aa8feeefd3ac6c78ee8f67bf033976fc7d68bc6d.

Don't use Optional::hasValue (NFC)

[clang] Don't use Optional::getValue (NFC)

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`,

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
fc3090109643af8d2da9822d0f99c84742b9c877,
a571f82a50416b767fd3cce0fb5027bb5dfec58c,
64c045e25b8471bbb572bd29159c294a82a86a2, and
de6ddaeef3aaa8a9ae3663c12cdb57d9afc0f906,
and reverts aa643f455a5362de7189eac630050d2c8aefe8f2.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

Revert "Fixup D123950 to address revert of D123345"

This reverts commit aa643f455a5362de7189eac630050d2c8aefe8f2.

show more ...

Revert "Treat `std::move`, `forward`, etc. as builtins."

This reverts commit b27430f9f46b88bcd54d992debc8d72e131e1bd0 as the
parent https://reviews.llvm.org/D123345 breaks the AIX CI:

https

Revert "Treat `std::move`, `forward`, etc. as builtins."

This reverts commit b27430f9f46b88bcd54d992debc8d72e131e1bd0 as the
parent https://reviews.llvm.org/D123345 breaks the AIX CI:

https://lab.llvm.org/buildbot/#/builders/214/builds/819

show more ...

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`,

Treat `std::move`, `forward`, etc. as builtins.

This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

This is a re-commit of
fc3090109643af8d2da9822d0f99c84742b9c877,
a571f82a50416b767fd3cce0fb5027bb5dfec58c, and
64c045e25b8471bbb572bd29159c294a82a86a25
which were reverted in
e75d8b70370435b0ad10388afba0df45fcf9bfcc
due to a crasher bug where CodeGen would emit a builtin glvalue as an
rvalue if it constant-folds.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

show more ...

Revert "Treat `std::move`, `forward`, and `move_if_noexcept` as builtins."
Revert "Extend support for std::move etc to also cover std::as_const and"
Revert "Update test to handle opaque pointers flag

Revert "Treat `std::move`, `forward`, and `move_if_noexcept` as builtins."
Revert "Extend support for std::move etc to also cover std::as_const and"
Revert "Update test to handle opaque pointers flag flip."

It crashes on libcxx tests https://lab.llvm.org/buildbot/#/builders/85/builds/8174

This reverts commit fc3090109643af8d2da9822d0f99c84742b9c877.
This reverts commit a571f82a50416b767fd3cce0fb5027bb5dfec58c.
This reverts commit 64c045e25b8471bbb572bd29159c294a82a86a25.

show more ...

Extend support for std::move etc to also cover std::as_const and
std::addressof, plus the libstdc++-specific std::__addressof.

This brings us to parity with the corresponding GCC behavior.

Remove S

Extend support for std::move etc to also cover std::as_const and
std::addressof, plus the libstdc++-specific std::__addressof.

This brings us to parity with the corresponding GCC behavior.

Remove STDBUILTIN macro that ended up not being used.

show more ...

Treat `std::move`, `forward`, and `move_if_noexcept` as builtins.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addres

Treat `std::move`, `forward`, and `move_if_noexcept` as builtins.

We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.

This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.

We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.

In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.

The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D123345

show more ...

[clang][NFC] Inclusive terms: replace some uses of sanity in clang

Rewording of comments to avoid using `sanity test, sanity check`.

Reviewed By: aaron.ballman, Quuxplusone

Differential Revision:

[clang][NFC] Inclusive terms: replace some uses of sanity in clang

Rewording of comments to avoid using `sanity test, sanity check`.

Reviewed By: aaron.ballman, Quuxplusone

Differential Revision: https://reviews.llvm.org/D114025

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Implement if consteval (P1938)

Modify the IfStmt node to suppoort constant evaluated expressions.

Add a new ExpressionEvaluationContext::ImmediateFunctionContext to
keep track of immediate function

Implement if consteval (P1938)

Modify the IfStmt node to suppoort constant evaluated expressions.

Add a new ExpressionEvaluationContext::ImmediateFunctionContext to
keep track of immediate function contexts.

This proved easier/better/probably more efficient than walking the AST
backward as it allows diagnosing nested if consteval statements.

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[clang] NFC: Rename rvalue to prvalue

This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.

C++ has the most complicated taxonomy

[clang] NFC: Rename rvalue to prvalue

This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.

C++ has the most complicated taxonomy here, and every other language
only uses a subset of it, so it's less confusing to use the C++ names
consistently, and mentally remap to the C names when working on that
context (prvalue -> rvalue, no xvalues, etc).

Renames:
* VK_RValue -> VK_PRValue
* Expr::isRValue -> Expr::isPRValue
* SK_QualificationConversionRValue -> SK_QualificationConversionPRValue
* JSON AST Dumper Expression nodes value category: "rvalue" -> "prvalue"

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D103720

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