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:
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
emplace_back cannot construct an aggregate with arguments used to
initialize the aggregate.
Closes#62387
Test plan: Added test test from #62387 which contains code that should
not be replaced by the check.
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.
This removes the `ClassScopeFunctionSpecializationDecl` `Decl` node, and
instead uses `DependentFunctionTemplateSpecializationInfo` to handle
such declarations. `DependentFunctionTemplateSpecializationInfo` is also
changed to store a `const ASTTemplateArgumentListInfo*` to be more in
line with `FunctionTemplateSpecializationInfo`.
This also changes `FunctionDecl::isFunctionTemplateSpecialization` to
return `true` for dependent specializations, and
`FunctionDecl::getTemplateSpecializationKind`/`FunctionDecl::getTemplateSpecializationKindForInstantiation`
to return `TSK_ExplicitSpecialization` for non-friend dependent
specializations (the same behavior as dependent class scope
`ClassTemplateSepcializationDecl` & `VarTemplateSepcializationDecl`).
This patch improves the modernize-use-emplace check by adding support for
detecting inefficient invocations of the `push` and `push_front` methods on
STL-style containers and replacing them with their `emplace`-style equivalent.
Fixes#56996.
Reviewed By: njames93
Differential Revision: https://reviews.llvm.org/D131623
modernize-use-emplace only recommends going from a push_back to an
emplace_back, but does not provide a recommendation when emplace_back is
improperly used. This adds the functionality of warning the user when
an unecessary temporary is created while calling emplace_back or other "emplacy"
functions from the STL containers.
Reviewed By: kuhar, ivanmurashko
Differential Revision: https://reviews.llvm.org/D101471
There's many instances in clang tidy checks where owning strings are used when we already have a stable string from the options, so using a StringRef makes much more sense.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D124341
Just adds the storeOptions for Checks that weren't already storing their options.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D82223
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
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
Summary:
This patch makes modernize-use-emplace remove unnecessary make_ calls from push_back calls and turn them into emplace_back -- the same way make_pair calls are handled.
Custom make_ calls can be removed for custom tuple-like types -- two new options that control that are `TupleTypes` and `TupleMakeFunctions`. By default, the check removes calls to `std::make_pair` and `std::make_tuple`.
Eq.
```
std::vector<std::tuple<int, char, bool>> v;
v.push_back(std::make_tuple(1, 'A', true)); // --> v.emplace_back(1, 'A', true);
```
Reviewers: alexfh, aaron.ballman, Prazek, hokein
Reviewed By: Prazek
Subscribers: JDevlieghere, xazax.hun, JonasToth, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D32690
llvm-svn: 303145
Summary:
This patch makes modernize-use-emplace remove unnecessary make_ calls from push_back calls and turn them into emplace_back -- the same way make_pair calls are handled.
Custom make_ calls can be removed for custom tuple-like types -- two new options that control that are `TupleTypes` and `TupleMakeFunctions`. By default, the check removes calls to `std::make_pair` and `std::make_tuple`.
Eq.
```
std::vector<std::tuple<int, char, bool>> v;
v.push_back(std::make_tuple(1, 'A', true)); // --> v.emplace_back(1, 'A', true);
```
Reviewers: alexfh, aaron.ballman, Prazek, hokein
Reviewed By: Prazek
Subscribers: JDevlieghere, xazax.hun, JonasToth, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D32690
llvm-svn: 303139
Summary: Use the cxxStdInitializerListExp matcher from ASTMatchers.h instead of a local one.
Reviewers: aaron.ballman, alexfh, Prazek
Reviewed By: aaron.ballman
Subscribers: xazax.hun, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D32923
llvm-svn: 302317
Summary:
This patch fixes [[ https://bugs.llvm.org/show_bug.cgi?id=32896 | PR32896 ]].
The problem was that modernize-use-emplace incorrectly removed changed push_back into emplace_back, removing explicit constructor call with initializer list parameter, resulting in compiler error after applying fixits.
modernize-use-emplace used to check if matched constructor had InitListExpr, but didn't check against CXXStdInitializerListExpr.
Eg.
```
std::vector<std::vector<int>> v;
v.push_back(std::vector<int>({1})); // --> v.emplace_back({1});
```
Reviewers: Prazek, alexfh, aaron.ballman
Reviewed By: Prazek, alexfh, aaron.ballman
Subscribers: xazax.hun, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D32767
llvm-svn: 302281
Summary:
When there is a push_back with a call to make_pair, turn it into emplace_back and remove the unnecessary make_pair call.
Eg.
```
std::vector<std::pair<int, int>> v;
v.push_back(std::make_pair(1, 2)); // --> v.emplace_back(1, 2);
```
make_pair doesn't get removed when explicit template parameters are provided, because of potential problems with type conversions.
Reviewers: Prazek, aaron.ballman, hokein, alexfh
Reviewed By: Prazek, alexfh
Subscribers: JDevlieghere, JonasToth, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D32395
llvm-svn: 301651
