Rework the `Option` library to reduce dynamic relocations (#119198)

Apologies for the large change, I looked for ways to break this up and
all of the ones I saw added real complexity. This change f

Rework the `Option` library to reduce dynamic relocations (#119198)

Apologies for the large change, I looked for ways to break this up and
all of the ones I saw added real complexity. This change focuses on the
option's prefixed names and the array of prefixes. These are present in
every option and the dominant source of dynamic relocations for PIE or
PIC users of LLVM and Clang tooling. In some cases, 100s or 1000s of
them for the Clang driver which has a huge number of options.

This PR addresses this by building a string table and a prefixes table
that can be referenced with indices rather than pointers that require
dynamic relocations. This removes almost 7k dynmaic relocations from the
`clang` binary, roughly 8% of the remaining dynmaic relocations outside
of vtables. For busy-boxing use cases where many different option tables
are linked into the same binary, the savings add up a bit more.

The string table is a straightforward mechanism, but the prefixes
required some subtlety. They are encoded in a Pascal-string fashion with
a size followed by a sequence of offsets. This works relatively well for
the small realistic prefixes arrays in use.

Lots of code has to change in order to land this though: both all the
option library code has to be updated to use the string table and
prefixes table, and all the users of the options library have to be
updated to correctly instantiate the objects.

Some follow-up patches in the works to provide an abstraction for this
style of code, and to start using the same technique for some of the
other strings here now that the infrastructure is in place.

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Reland "[flang][clang] Add Visibility specific help text for options (#81869)"

This reverts commit 67d20412b448533c77f54ac7a1e5d0775d273729.

This includes fixes for clanginstallapi.

Revert "[flang][clang] Add Visibility specific help text for options (#81869)"

This reverts commit 7e958f64efea6cb824e96ace51e021afbc150922.

Failing on multiple bots.

[flang][clang] Add Visibility specific help text for options (#81869)

And use it to print the correct default OpenMP version for flang and
flang -fc1.

This change adds an optional `HelpTextsForV

[flang][clang] Add Visibility specific help text for options (#81869)

And use it to print the correct default OpenMP version for flang and
flang -fc1.

This change adds an optional `HelpTextsForVariants` to options. This
allows you to change the help text that gets shown in documentation and
`--help` based on the program its being generated for.

As `OptTable` needs to be constexpr compatible, I have used a std::array
of help text variants. Each entry is:
(list of visibilities) - > help text string

So for the OpenMP version we have (flang, fc1) -> "OpenMP version for
flang is...".

So you can have multiple visibilities use the same string. The number of
entries is currently set to 1, and the number of visibilities per entry
is 2, because that's the maximum we need for now. The code is written so
we can increase these numbers later, and the unused elements will be initialised.

I have not applied this to group descriptions just because I don't know
of one that needs changing. It could easily be enabled for those too if
needed. There are minor changes to them just to get it all to compile.

This approach of storing many help strings per option in the 1 driver
library seemed preferable to making a whole new library for Flang (even
if that would mostly be including stuff from Clang).

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[clangd] Use SmallString::operator std::string (NFC)

[clangd] Use starts_with instead of startswith in CompileCommands.cpp (NFC)

llvm-project/clang-tools-extra/clangd/CompileCommands.cpp:324:52:
error: 'startswith' is deprecated: Use starts_with inst

[clangd] Use starts_with instead of startswith in CompileCommands.cpp (NFC)

llvm-project/clang-tools-extra/clangd/CompileCommands.cpp:324:52:
error: 'startswith' is deprecated: Use starts_with instead [-Werror,-Wdeprecated-declarations]
324 | Cmd, [&](llvm::StringRef Arg) { return Arg.startswith(Flag); });
| ^~~~~~~~~~
| starts_with

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[clangd] Fix sysroot flag handling in CommandMangler to prevent duplicates (#75694)

CommandMangler should guess the sysroot path of the host system and add
that through `-isysroot` flag only when t

[clangd] Fix sysroot flag handling in CommandMangler to prevent duplicates (#75694)

CommandMangler should guess the sysroot path of the host system and add
that through `-isysroot` flag only when there is no `--sysroot` or
`-isysroot` flag in the original compile command to avoid duplicate
sysroot.

Previously, CommandMangler appropriately avoided adding a guessed
sysroot flag if the original command had an argument in the form of
`--sysroot=<sysroot>`, `--sysroot <sysroot>`, or `-isysroot <sysroot>`.
However, when presented as `-isysroot<sysroot>` (without spaces after
`-isysroot`), CommandMangler mistakenly appended the guessed sysroot
flag, resulting in duplicated sysroot in the final command.

This commit fixes it, ensuring the final command has no duplicate
sysroot flags. Also adds unit tests for this fix.

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[clangd] Expand response files before CDB interpolation (#75753)

Summary:

After https://reviews.llvm.org/D143436 response files stopped working
with CDB interpolation. It has happened because in

[clangd] Expand response files before CDB interpolation (#75753)

Summary:

After https://reviews.llvm.org/D143436 response files stopped working
with CDB interpolation. It has happened because interpolation removes
all unknown flags and extra input files. Response file is treated as an
extra input because it is not a flag. Moreover inference needs full
command line for driver mode and file type detection so all response
files have to be expanded for correct inference.

This patch partially reverts D143436 and add additional response file
expansion in OverlayCDB for CDBs pushed via LSP.

Test Plan: check-clangd

Tasks: https://github.com/llvm/llvm-project/issues/69690

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[clangd] Use StringRef::{starts,ends}_with (NFC)

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

[clangd] Use StringRef::{starts,ends}_with (NFC)

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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[clang-tools-extra] Use range-based for loops (NFC)

[Driver] Refactor to use llvm Option's new Visibility flags

This is a big refactor of the clang driver's option handling to use
the Visibility flags introduced in https://reviews.llvm.org/D157149.
T

[Driver] Refactor to use llvm Option's new Visibility flags

This is a big refactor of the clang driver's option handling to use
the Visibility flags introduced in https://reviews.llvm.org/D157149.
There are a few distinct parts, but they can't really be split into
separate commits and still be made to compile.

1. We split out some of the flags in ClangFlags to ClangVisibility.
Note that this does not include any subtractive flags.

2. We update the Flag definitions and OptIn/OptOut constructs in
Options.td by hand.

3. We introduce and use a script, update_options_td_flags, to ease
migration of flag definitions in Options.td, and we run that on
Options.td. I intend to remove this later, but I'm committing it so
that downstream forks can use the script to simplify merging.

4. We update calls to OptTable in the clang driver, cc1as, flang, and
clangd to use the visibility APIs instead of Include/Exclude flags.

5. We deprecate the Include/Exclude APIs and add a release note.

*if you are running into conflicts with this change:*

Note that https://reviews.llvm.org/D157150 may also be the culprit and
if so it should be handled first.

The script in `clang/utils/update_options_td_flags.py` can help. Take
the downstream side of all conflicts and then run the following:

```
% cd clang/include/clang/Driver
% ../../../utils/update_options_td_flags.py Options.td > Options.td.new
% mv Options.td.new Options.td
```

This will hopefully be sufficient, please take a look at the diff.

Differential Revision: https://reviews.llvm.org/D157151

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Reapply "[Option] Add "Visibility" field and clone the OptTable APIs to use it"

This reverts commit 4e3b89483a6922d3f48670bb1c50a37f342918c6, with
fixes for places I'd missed updating in lld and lld

Reapply "[Option] Add "Visibility" field and clone the OptTable APIs to use it"

This reverts commit 4e3b89483a6922d3f48670bb1c50a37f342918c6, with
fixes for places I'd missed updating in lld and lldb. I've also
renamed OptionVisibility::Default to "DefaultVis" to avoid ambiguity
since the undecorated name has to be available anywhere Options.inc is
included.

Original message follows:

This splits OptTable's "Flags" field into "Flags" and "Visibility",
updates the places where we instantiate Option tables, and adds
variants of the OptTable APIs that use Visibility mask instead of
Include/Exclude flags.

We need to do this to clean up a bunch of complexity in the clang
driver's option handling - there's a whole slew of flags like
CoreOption, NoDriverOption, and FlangOnlyOption there today to try to
handle all of the permutations of flags that the various drivers need,
but it really doesn't scale well, as can be seen by things like the
somewhat recently introduced CLDXCOption.

Instead, we'll provide an additive model for visibility that's
separate from the other flags. For things like "HelpHidden", which is
used as a "subtractive" modifier for option visibility, we leave that
in "Flags" and handle it as a special case.

Note that we don't actually update the users of the Include/Exclude
APIs here or change the flags that exist in clang at all - that will
come in a follow up that refactors clang's Options.td to use the
increased flexibility this change allows.

Differential Revision: https://reviews.llvm.org/D157149

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Revert "[Option] Add "Visibility" field and clone the OptTable APIs to use it"

this is failing on bots, reverting to investigate.

This reverts commit a16104e6da6f36f3d72dbf53d10ba56495a0d65a.

[Option] Add "Visibility" field and clone the OptTable APIs to use it

This splits OptTable's "Flags" field into "Flags" and "Visibility",
updates the places where we instantiate Option tables, and a

[Option] Add "Visibility" field and clone the OptTable APIs to use it

This splits OptTable's "Flags" field into "Flags" and "Visibility",
updates the places where we instantiate Option tables, and adds
variants of the OptTable APIs that use Visibility mask instead of
Include/Exclude flags.

We need to do this to clean up a bunch of complexity in the clang
driver's option handling - there's a whole slew of flags like
CoreOption, NoDriverOption, and FlangOnlyOption there today to try to
handle all of the permutations of flags that the various drivers need,
but it really doesn't scale well, as can be seen by things like the
somewhat recently introduced CLDXCOption.

Instead, we'll provide an additive model for visibility that's
separate from the other flags. For things like "HelpHidden", which is
used as a "subtractive" modifier for option visibility, we leave that
in "Flags" and handle it as a special case.

Note that we don't actually update the users of the Include/Exclude
APIs here or change the flags that exist in clang at all - that will
come in a follow up that refactors clang's Options.td to use the
increased flexibility this change allows.

Differential Revision: https://reviews.llvm.org/D157149

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[llvm] Construct option's prefixed name at compile-time

Some Clang command-line handling code could benefit from the option's prefixed name being a `StringLiteral`. This patch changes the `llvm::opt

[llvm] Construct option's prefixed name at compile-time

Some Clang command-line handling code could benefit from the option's prefixed name being a `StringLiteral`. This patch changes the `llvm::opt` TableGen backend to generate and emit that into the .inc file.

Depends on D157028.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D157029

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Revert "[OptTable] Make explicitly included options override excluded ones"

Looks like a couple of flang bots are broken by this change. Reverting
to investigate.

This reverts commit b2eda85f047f27

Revert "[OptTable] Make explicitly included options override excluded ones"

Looks like a couple of flang bots are broken by this change. Reverting
to investigate.

This reverts commit b2eda85f047f27788ccd7b9af9bd59c5d44b2051.

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[OptTable] Make explicitly included options override excluded ones

When we have both explicitly included and excluded option sets, we
were excluding anything from the latter set regardless of what w

[OptTable] Make explicitly included options override excluded ones

When we have both explicitly included and excluded option sets, we
were excluding anything from the latter set regardless of what was in
the former. This doesn't compose well and led to an overly complicated
design around DXC options where a third flag was introduced to handle
options that overlapped between DXC and CL.

With this change we check the included options before excluding
anything from the exclude list, which allows for options that are in
multiple categories to be handled in a sensible way. This allows us to
remove CLDXCOption but should otherwise be NFC.

Differential Revision: https://reviews.llvm.org/D155729

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Migrate {starts,ends}with_insensitive to {starts,ends}_with_insensitive (NFC)

This patch migrates uses of StringRef::{starts,ends}with_insensitive
to StringRef::{starts,ends}_with_insensitive so tha

Migrate {starts,ends}with_insensitive to {starts,ends}_with_insensitive (NFC)

This patch migrates uses of StringRef::{starts,ends}with_insensitive
to StringRef::{starts,ends}_with_insensitive so that we can use names
similar to those used in std::string_view.

Note that the llvm/ directory has migrated in commit
6c3ea866e93003e16fc55d3b5cedd3bc371d1fde.

I'll post a separate patch to deprecate
StringRef::{starts,ends}with_insensitive.

Differential Revision: https://reviews.llvm.org/D150506

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[clangd] Move standard options adaptor to CommandMangler

There is a discrepancy between how clangd processes CDB loaded from
JSON file on disk and pushed via LSP. Thus the same CDB pushed via
LSP pr

[clangd] Move standard options adaptor to CommandMangler

There is a discrepancy between how clangd processes CDB loaded from
JSON file on disk and pushed via LSP. Thus the same CDB pushed via
LSP protocol may not work as expected. Some difference between these two
paths is expected but we still need to insert driver mode and target from
binary name and expand response files.

Test Plan: check-clang-tools

Differential Revision: https://reviews.llvm.org/D143436

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Revert "[clangd] Move standard options adaptor to CommandMangler"

This reverts commit 34de7da6246cdfa6ff6f3d3c514583cddc0a10ec.

[clangd] Move standard options adaptor to CommandMangler

There is a discrepancy between how clangd processes CDB loaded from
JSON file on disk and pushed via LSP. Thus the same CDB pushed via
LSP pr

[clangd] Move standard options adaptor to CommandMangler

There is a discrepancy between how clangd processes CDB loaded from
JSON file on disk and pushed via LSP. Thus the same CDB pushed via
LSP protocol may not work as expected. Some difference between these two
paths is expected but we still need to insert driver mode and target from
binary name and expand response files.

Test Plan: check-clang-tools

Differential Revision: https://reviews.llvm.org/D143436

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Move from llvm::makeArrayRef to ArrayRef deduction guides - last part

This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Re

Move from llvm::makeArrayRef to ArrayRef deduction guides - last part

This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141298

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[clang-tools-extra] Use std::optional instead of llvm::Optional (NFC)

This patch replaces (llvm::|)Optional< with std::optional<. I'll post
a separate patch to clean up the "using" declarations, #i

[clang-tools-extra] Use std::optional instead of llvm::Optional (NFC)

This patch replaces (llvm::|)Optional< with std::optional<. I'll post
a separate patch to clean up the "using" declarations, #include
"llvm/ADT/Optional.h", etc.

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 a StringRef instead of a raw char pointer to store builtin and call information

This avoids recomputing string length that is already known at compile time.

It has a slight impact on pr

[clang] Use a StringRef instead of a raw char pointer to store builtin and call information

This avoids recomputing string length that is already known at compile time.

It has a slight impact on preprocessing / compile time, see

https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u

This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.

The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.

Differential Revision: https://reviews.llvm.org/D139881

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Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4 (part 2)"
Revert "

Revert "[clang] Use a StringRef instead of a raw char pointer to store builtin and call information"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4 (part 2)"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4"

GCC build hangs on this bot https://lab.llvm.org/buildbot/#/builders/37/builds/19104
compiling CMakeFiles/obj.clangBasic.dir/Targets/AArch64.cpp.d

The bot uses GNU 11.3.0, but I can reproduce locally with gcc (Debian 12.2.0-3) 12.2.0.

This reverts commit caa713559bd38f337d7d35de35686775e8fb5175.
This reverts commit 06b90e2e9c991e211fecc97948e533320a825470.
This reverts commit e953ae5bbc313fd0cc980ce021d487e5b5199ea4.

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