14 Commits

Author SHA1 Message Date
Matheus Izvekov
91cdd35008
[clang] Improve nested name specifier AST representation (#147835)
This is a major change on how we represent nested name qualifications in
the AST.

* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.

This patch offers a great performance benefit.

It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.

This has great results on compile-time-tracker as well:

![image](https://github.com/user-attachments/assets/700dce98-2cab-4aa8-97d1-b038c0bee831)

This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.

It has some other miscelaneous drive-by fixes.

About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.

There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.

How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.

The rest and bulk of the changes are mostly consequences of the changes
in API.

PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.

Fixes #136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
2025-08-09 05:06:53 -03:00
Kazu Hirata
ba007a60d0
[clang-tidy] Remove unused includes (NFC) (#141420)
These are identified by misc-include-cleaner.  I've filtered out those
that break builds.  Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
2025-05-25 10:55:36 -07:00
Piotr Zegar
11a411a49b Revert "[clang-tidy][NFC] Remove duplicated code"
This reverts commit b6f6be4b500ff64c23a5103ac3311cb74519542f.
2024-03-31 15:06:49 +00:00
Piotr Zegar
b6f6be4b50 [clang-tidy][NFC] Remove duplicated code
Remove duplicated matchers by moving some of them to
utils/Matchers.h. Add some anonymous namespaces and
renamed some code to avoid ODR issues.
2024-03-31 14:58:27 +00:00
Carlos Galvez
7d2ea6c422 [clang-tidy][NFC] Use C++17 nested namespaces in the clang-tidy folder
Fix applied by running:

run-clang-tidy.py -checks=-*,modernize-concat-nested-namespaces

Differential Revision: https://reviews.llvm.org/D141770
2023-01-14 18:51:39 +00:00
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
Nathan James
1a721b6a26
[clang-tidy][NFC] Tweak some generation of diag messages
Fix up cases where diag is called by piecing together a string in favour of placeholders.
Fix up cases where select could be used instead of duplicating the message for sake of 1 word difference.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D97488
2021-02-26 19:10:25 +00:00
Nathan James
db90d31570
[clang-tidy] Implement storeOptions for checks missing it.
Just adds the storeOptions for Checks that weren't already storing their options.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D82223
2020-06-21 19:01:11 +01:00
Nathan James
672207c319 [clang-tidy] Convert config options that are bools to use the bool overload of get(GlobalOrLocal)?
Summary: This was done with a script that looks for calls to Options.get(GlobalOrLocal) that take an integer for the second argument and the result is either compared not equal to 0 or implicitly converted to bool. There may be other occurances

Reviewers: aaron.ballman, alexfh, gribozavr2

Reviewed By: aaron.ballman

Subscribers: wuzish, nemanjai, xazax.hun, kbarton, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77831
2020-04-12 23:06:09 +01:00
Nathan James
e40a742a50 [clang-tidy] Change checks to use new isLanguageVersionSupported restriction
Summary: Modifies all checks that are language version dependent to use `isLanguageVersionSupported`

Reviewers: jdoerfert, lebedev.ri, aaron.ballman, gribozavr2, Eugene.Zelenko

Reviewed By: gribozavr2

Subscribers: wuzish, nemanjai, xazax.hun, hiraditya, kbarton, steven_wu, dexonsmith, arphaman, lebedev.ri, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75340
2020-03-03 16:43:45 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Benjamin Kramer
bb999e507c [modernize-use-transparent-functors] TypeLocs can be implicitly created, don't crash when encountering those.
llvm-svn: 342252
2018-09-14 18:05:30 +00:00
Stephen Kelly
43465bf3fd Port getLocStart -> getBeginLoc
Reviewers: javed.absar

Subscribers: nemanjai, kbarton, ilya-biryukov, ioeric, jkorous, arphaman, jfb, cfe-commits

Differential Revision: https://reviews.llvm.org/D50354

llvm-svn: 339400
2018-08-09 22:42:26 +00:00
Gabor Horvath
678dd8fc62 [clang-tidy] New check to prefer transparent functors to non-transparent ones.
llvm-svn: 287107
2016-11-16 14:42:10 +00:00