There's `arrayType` matcher for matching `ArrayType`, but no matcher for
`ArrayTypeLoc`. This change complements it.
Note that there's already `hasElementTypeLoc` matcher, which was
declared together with the `hasElementType` matcher.
A DependentTemplateSpecializationType (DTST) is basically just a
TemplateSpecializationType (TST) with a hardcoded DependentTemplateName
(DTN) as its TemplateName.
This removes the DTST and replaces all uses of it with a TST, removing a
lot of duplication in the implementation.
Technically the hardcoded DTN is an optimization for a most common case,
but the TST implementation is in better shape overall and with other
optimizations, so this patch ends up being an overall performance
positive:
<img width="1465" height="38" alt="image"
src="https://github.com/user-attachments/assets/084b0694-2839-427a-b664-eff400f780b5"
/>
A DTST also didn't allow a template name representing a DTN that was
substituted, such as from an alias template, while the TST does allow it
by the simple fact it can hold an arbitrary TemplateName, so this patch
also increases the amount of sugar retained, while still being faster
overall.
Example (from included test case):
```C++
template<template<class> class TT> using T1 = TT<int>;
template<class T> using T2 = T1<T::template X>;
```
Here we can now represent in the AST that `TT` was substituted for the
dependent template name `T::template X`.
Makes sure UnconventionalAssignOperatorCheck checks if the types
reference the same entity, not the exact declaration.
This adds a new matcher to support this check.
This fixes a regression introduced by #147835. Since this regression was
never released, there are no release notes.
Fixes#153770
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
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.
* Don't call raw_string_ostream::flush(), which is essentially a no-op.
* Strip unneeded calls to raw_string_ostream::str(), to avoid extra indirection.
Note that this patch will be necessary to fix
`forEachArgumentWithParam()` and `forEachArgumentWithParamType()`
matchers for deducing "this"; which is my true motivation. There the bug
is that with explicit obj params, one should not adjust the number of
arguments in presence of `CXXMethodDecls`, and this causes a mismatch
there mapping the argument to the wrong param. But, I'll come back there
once we have this matcher.
Adds support for the following matchers related to `CXXFoldExpr`:
`cxxFoldExpr`, `callee`,
`hasInit`, `hasPattern`, `isRightFold`, `isLeftFold`,
`isUnaryFold`, `isBinaryFold`, `hasOperator`, `hasLHS`, `hasRHS`.
This will be used by the modernize-use-std-print clang-tidy check and
related checks later.
Reviewed By: PiotrZSL
Differential Revision: https://reviews.llvm.org/D153716
This was added to the static matchers in
125ccd3751472a0c709498f83671577ffed394a6, but the dynamic matcher was
missed. This adds the dynamic matcher to the list.
Fixes the `FIXME:` related to adding `forEachTemplateArgument` to the
core AST Matchers library.
Reviewed By: aaron.ballman
Differential Revision: http://reviews.llvm.org/D125383
This reverts commit cc56c66f27e131b914082d3bd21180646e842e9a.
Fixed a bad assertion, the target of a UsingShadowDecl must not have
*local* qualifiers, but it can be a typedef whose underlying type is qualified.
Currently there's no way to find the UsingDecl that a typeloc found its
underlying type through. Compare to DeclRefExpr::getFoundDecl().
Design decisions:
- a sugar type, as there are many contexts this type of use may appear in
- UsingType is a leaf like TypedefType, the underlying type has no TypeLoc
- not unified with UnresolvedUsingType: a single name is appealing,
but being sometimes-sugar is often fiddly.
- not unified with TypedefType: the UsingShadowDecl is not a TypedefNameDecl or
even a TypeDecl, and users think of these differently.
- does not cover other rarer aliases like objc @compatibility_alias,
in order to be have a concrete API that's easy to understand.
- implicitly desugared by the hasDeclaration ASTMatcher, to avoid
breaking existing patterns and following the precedent of ElaboratedType.
Scope:
- This does not cover types associated with template names introduced by
using declarations. A future patch should introduce a sugar TemplateName
variant for this. (CTAD deduced types fall under this)
- There are enough AST matchers to fix the in-tree clang-tidy tests and
probably any other matchers, though more may be useful later.
Caveats:
- This changes a fairly common pattern in the AST people may depend on matching.
Previously, typeLoc(loc(recordType())) matched whether a struct was
referred to by its original scope or introduced via using-decl.
Now, the using-decl case is not matched, and needs a separate matcher.
This is similar to the case of typedefs but nevertheless both adds
complexity and breaks existing code.
Differential Revision: https://reviews.llvm.org/D114251
This contributes follow-up work from https://reviews.llvm.org/D112491, which
allows for increased control over the matching of lambda captures. This also
updates the documentation for the `lambdaCapture` matcher.
Reviewed By: ymandel, aaron.ballman
Differential Revision: https://reviews.llvm.org/D113575
This provides better support for `LambdaCapture`s by making them first-
class and allowing them to be bindable. In addition, this implements several
`LambdaCapture`-related matchers. This does not update how lambdas are
traversed. As a result, something like trying to match `lambdaCapture()` by
itself will not work - it must be used as an inner matcher.
Reviewed By: aaron.ballman, sammccall
Differential Revision: https://reviews.llvm.org/D112491
This implements the 'using enum maybe-qualified-enum-tag ;' part of
1099. It introduces a new 'UsingEnumDecl', subclassed from
'BaseUsingDecl'. Much of the diff is the boilerplate needed to get the
new class set up.
There is one case where we accept ill-formed, but I believe this is
merely an extended case of an existing bug, so consider it
orthogonal. AFAICT in class-scope the c++20 rule is that no 2 using
decls can bring in the same target decl ([namespace.udecl]/8). But we
already accept:
struct A { enum { a }; };
struct B : A { using A::a; };
struct C : B { using A::a;
using B::a; }; // same enumerator
this patch permits mixtures of 'using enum Bob;' and 'using Bob::member;' in the same way.
Differential Revision: https://reviews.llvm.org/D102241
The new matcher additionally covers blocks and Objective-C methods.
This matcher actually makes sure that the statement truly belongs
to that declaration's body. forFunction() incorrectly reported that
a statement in a nested block belonged to the surrounding function.
forFunction() is now deprecated due to the above footgun, in favor of
forCallable(functionDecl()) when only functions need to be considered.
Differential Revision: https://reviews.llvm.org/D102213
Required for capturing base specifier in matchers:
`cxxRecordDecl(hasDirectBase(cxxBaseSpecifier().bind("base")))`
Reviewed By: steveire, aaron.ballman
Differential Revision: https://reviews.llvm.org/D69218