11 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
Sirraide
b0210fee94
[Clang] [NFC] Fix more -Wreturn-type warnings in tests everywhere (#123470)
With the goal of eventually being able to make `-Wreturn-type` default to an 
error in all language modes, this is a follow-up to #123464 and updates even
more tests, mainly clang-tidy and clangd tests.
2025-02-20 19:49:37 +01:00
Sam McCall
4d006520b8 [clangd] Clean up unused includes. NFCI
Add includes where needed to fix build.
Haven't systematically added used headers, so there is still accidental
dependency on transitive includes.
2022-02-26 12:00:16 +01:00
Christian Kühnel
8edfc2f814 [clangd] Cleanup of readability-identifier-naming
Auto-generated patch based on clang-tidy readability-identifier-naming.
Only some manual cleanup for `extern "C"` declarations and a GTest change was required.

I'm not sure if this cleanup is actually very useful. It cleans up clang-tidy findings to the number of warnings from clang-tidy should be lower.  Since it was easy to do and required only little cleanup I thought I'd upload it for discussion.

One pattern that keeps recurring: Test **matchers** are also supposed to start with a lowercase letter as per LLVM convention. However GTest naming convention for matchers start with upper case. I would propose to keep stay consistent with the GTest convention there. However that would imply a lot of `//NOLINT` throughout these files.

To re-product this patch run:
```
run-clang-tidy -checks="-*,readability-identifier-naming" -fix -format ./clang-tools-extra/clangd
```

To convert the macro names, I was using this script with some manual cleanup afterwards:
https://gist.github.com/ChristianKuehnel/a01cc4362b07c58281554ab46235a077

Differential Revision: https://reviews.llvm.org/D115634
2022-02-01 13:31:52 +00:00
Sam McCall
055d8090d1 [clangd] Don't index __reserved_names in headers.
Main use of these is in the standard library, where they generally clutter up
the index.

Certain macros are also common, we don't touch indexing of macros in this patch.

Differential Revision: https://reviews.llvm.org/D115301
2022-01-05 16:34:04 +01:00
Sam McCall
7d1b499cae Revert "[clangd] Extract symbol-scope logic out of Quality, add tests. NFC"
On second thought, this can't properly be reused for highlighting.

Consider this example, which Quality wants to consider function-scope,
but highlighting must consider class-scope:

void foo() {
  class X {
    int ^y;
  };
}
2021-01-29 14:59:16 +01:00
Sam McCall
d0817b5f18 [clangd] Extract symbol-scope logic out of Quality, add tests. NFC
This prepares for reuse from the semantic highlighting code.

There's a bit of yak-shaving here:
 - when the enum is moved into the clangd namespace, promote it to a
   scoped enum. This means teaching the decision forest infrastructure
   to deal with scoped enums.
 - AccessibleScope isn't quite the right name: e.g. public class members
   are treated as accessible, but still have class scope. So rename to
   SymbolScope.
 - Rename some QualitySignals members to avoid name conflicts.
   (the string) SymbolScope -> Scope
   (the enum) Scope -> ScopeKind
2021-01-29 14:44:28 +01:00
Utkarsh Saxena
9b1666f3ce [clangd] Rename evaluate() to evaluateHeuristics()
Since we have 2 scoring functions (heuristics and decision forest),
renaming the existing evaluate() function to be more descriptive of the
Heuristics being evaluated in it.

Differential Revision: https://reviews.llvm.org/D88431
2020-09-28 20:05:01 +02:00
Sam McCall
d3260bf5b2 [clangd] Errors in TestTU cause test failures unless suppressed with error-ok.
Summary:
The historic behavior of TestTU is to gather diagnostics and otherwise ignore
them. So if a test has a syntax error, and doesn't assert diagnostics, it
silently misbehaves.
This can be annoying when developing tests, as evidenced by various tests
gaining "assert no diagnostics" where that's not really the point of the test.

This patch aims to make that default behavior. For the first error
(not warning), TestTU will call ADD_FAILURE().

This can be suppressed with a comment containing "error-ok". For now that will
suppress any errors in the TU. We can make this stricter later -verify style.
(-verify itself is hard to reuse because of DiagnosticConsumer interfaces...)
A magic-comment was chosen over a TestTU option because of table-driven tests.

In addition to the behavior change, this patch:
  - adds //error-ok where we're knowingly testing invalid code
    (e.g. for diagnostics, crash-resilience, or token-level tests)
  - fixes a bunch of errors in the checked-in tests, mostly trivial (missing ;)
  - removes a bunch of now-redundant instances of "assert no diagnostics"

Reviewers: kadircet

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73199
2020-01-24 11:16:27 +01:00
Sam McCall
9fb22b2c86 [clangd] Boost code completion results that were named in the last few lines.
Summary:
The hope is this will catch a few patterns with repetition:

  SomeClass* S = ^SomeClass::Create()

  int getFrobnicator() { return ^frobnicator_; }

  // discard the factory, it's no longer valid.
  ^MyFactory.reset();

Without triggering antipatterns too often:

  return Point(x.first, x.^second);

I'm going to gather some data on whether this turns out to be a win overall.

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, jfb, kadircet, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D61537

llvm-svn: 360030
2019-05-06 10:25:10 +00:00
Sam McCall
b804eef090 [clangd] Move clangd tests to clangd directory. check-clangd is no longer part of check-clang-tools.
Summary:
Motivation:
 - this layout is a pain to work with
 - without a common root, it's painful to express things like "disable clangd" (D61122)
 - CMake/lit configs are a maintenance hazard, and the more the one-off hacks
   for various tools are entangled, the more we see apathy and non-ownership.

This attempts to use the bare-minimum configuration needed (while still
supporting the difficult cases: windows, standalone clang build, dynamic libs).
In particular the lit.cfg.py and lit.site.cfg.py.in are merged into lit.cfg.in.
The logic in these files is now minimal.

(Much of clang-tools-extra's lit configs can probably be cleaned up by reusing
lit.llvm.llvm_config.use_clang(), and every llvm project does its own version of
LDPATH mangling. I haven't attempted to fix any of those).

Docs are still in clang-tools-extra/docs, I don't have any plans to touch those.

Reviewers: gribozavr

Subscribers: mgorny, javed.absar, MaskRay, jkorous, arphaman, kadircet, jfb, cfe-commits, ilya-biryukov, thakis

Tags: #clang

Differential Revision: https://reviews.llvm.org/D61187

llvm-svn: 359424
2019-04-29 08:44:01 +00:00