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
This PR introduces the use of pointer authentication to objective-c[++].
This includes:
* __ptrauth qualifier support for ivars
* protection of isa and super fields
* protection of SEL typed ivars
* protection of class_ro_t data
* protection of methodlist pointers and content
This patch adds templated `operator<<` for diagnostics that pass scoped
enums, saving people from `llvm::to_underlying()` clutter on the side of
emitting the diagnostic. This eliminates 80 out of 220 usages of
`llvm::to_underlying()` in Clang.
I also backported `std::is_scoped_enum_v` from C++23.
This PR reland https://github.com/llvm/llvm-project/pull/135808, fixed
some missed changes in LLDB.
I found this issue when I working on
https://github.com/llvm/llvm-project/pull/107168.
Currently we have many similiar data structures like:
- std::pair<IdentifierInfo *, SourceLocation>.
- Element type of ModuleIdPath.
- IdentifierLocPair.
- IdentifierLoc.
This PR unify these data structures to IdentifierLoc, moved
IdentifierLoc definition to SourceLocation.h, and deleted other similer
data structures.
---------
Signed-off-by: yronglin <yronglin777@gmail.com>
Reverts llvm/llvm-project#135808
Example from the LLDB macOS CI:
https://green.lab.llvm.org/job/llvm.org/view/LLDB/job/as-lldb-cmake/24084/execution/node/54/log/?consoleFull
```
/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/lldb/source/Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.cpp:360:49: error: no viable conversion from 'std::pair<clang::IdentifierInfo *, clang::SourceLocation>' to 'clang::ModuleIdPath' (aka 'ArrayRef<IdentifierLoc>')
clang::Module *top_level_module = DoGetModule(clang_path.front(), false);
^~~~~~~~~~~~~~~~~~
/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:41:40: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'std::pair<clang::IdentifierInfo *, clang::SourceLocation>' to 'const llvm::ArrayRef<clang::IdentifierLoc> &' for 1st argument
class LLVM_GSL_POINTER [[nodiscard]] ArrayRef {
^
/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:41:40: note: candidate constructor (the implicit move constructor) not viable: no known conversion from 'std::pair<clang::IdentifierInfo *, clang::SourceLocation>' to 'llvm::ArrayRef<clang::IdentifierLoc> &&' for 1st argument
/Users/ec2-user/jenkins/workspace/llvm.org/as-lldb-cmake/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:70:18: note: candidate constructor not viable: no known conversion from 'std::pair<clang::IdentifierInfo *, clang::SourceLocation>' to 'std::nullopt_t' for 1st argument
/*implicit*/ ArrayRef(std::nullopt_t) {}
```
I found this issue when I working on
https://github.com/llvm/llvm-project/pull/107168.
Currently we have many similiar data structures like:
- `std::pair<IdentifierInfo *, SourceLocation>`.
- Element type of `ModuleIdPath`.
- `IdentifierLocPair`.
- `IdentifierLoc`.
This PR unify these data structures to `IdentifierLoc`, moved
`IdentifierLoc` definition to SourceLocation.h, and deleted other
similer data structures.
---------
Signed-off-by: yronglin <yronglin777@gmail.com>
The layout and the size of an ObjC interface can change after its
corresponding implementation is parsed when synthesized ivars or ivars
declared in categories are added to the interface's list of ivars. This
can cause clang to mis-compile if the optimization that emits fixed
offsets for ivars (see 923ddf65f4e21ec67018cf56e823895de18d83bc) uses an
ObjC class layout that is outdated and no longer reflects the current
state of the class.
For example, when compiling `constant-non-fragile-ivar-offset.m`, clang
emits 20 instead of 24 as the offset for `IntermediateClass2Property` as
the class layout for `SuperClass2`, which is created when the
implementation of IntermediateClass3 is parsed, is outdated when the
implementation of `IntermediateClass2` is parsed.
This commit invalidates the stale layout information of the class and
its subclasses if new ivars are added to the interface.
With this change, we can also stop using ObjC implementation decls as
the key to retrieve ObjC class layouts information as the layout
retrieved using the ObjC interface as the key will always be up to date.
rdar://139531391
Note that PointerUnion::dyn_cast has been soft deprecated in
PointerUnion.h:
// FIXME: Replace the uses of is(), get() and dyn_cast() with
// isa<T>, cast<T> and the llvm::dyn_cast<T>
Literal migration would result in dyn_cast_if_present (see the
definition of PointerUnion::dyn_cast), but this patch uses dyn_cast
because we expect typeDecl to be nonnull. Note that
getObjCInterfaceType starts out dereferencing Decl.
This reverts commit 81fc3add1e627c23b7270fe2739cdacc09063e54.
This breaks some LLDB tests, e.g.
SymbolFile/DWARF/x86/no_unique_address-with-bitfields.cpp:
lldb: ../llvm-project/clang/lib/AST/Decl.cpp:4604: unsigned int clang::FieldDecl::getBitWidthValue() const: Assertion `isa<ConstantExpr>(getBitWidth())' failed.
Save the bitwidth value as a `ConstantExpr` with the value set. Remove
the `ASTContext` parameter from `getBitWidthValue()`, so the latter
simply returns the value from the `ConstantExpr` instead of
constant-evaluating the bitwidth expression every time it is called.
Note that PointerUnion::{is,get} have been soft deprecated in
PointerUnion.h:
// FIXME: Replace the uses of is(), get() and dyn_cast() with
// isa<T>, cast<T> and the llvm::dyn_cast<T>
I'm not touching PointerUnion::dyn_cast for now because it's a bit
complicated; we could blindly migrate it to dyn_cast_if_present, but
we should probably use dyn_cast when the operand is known to be
non-null.
Swift ClangImporter now supports concurrency annotations on imported
declarations and their parameters/results, to make it possible to use
imported APIs in Swift safely there has to be a way to annotate
individual parameters and result types with relevant attributes that
indicate that e.g. a block is called on a particular actor or it accepts
a `Sendable` parameter.
To faciliate that `SwiftAttr` is switched from `InheritableAttr` which
is a declaration attribute to `DeclOrTypeAttr`. To support this
attribute in type context we need access to its "Attribute" argument
which requires `AttributedType` to be extended to include `Attr *` when
available instead of just `attr::Kind` otherwise it won't be possible to
determine what attribute should be imported.
Before this change, ParseObjc would call the closing
`MaybeParseAttributes` before it had created Objective-C `ParmVarDecl`
objects (and associated name lookup entries), meaning that you could not
reference Objective-C method parameters in
`__attribute__((diagnose_if))`. This change moves the creation of the
`ParmVarDecl` objects ahead of calling `Sema::ActOnMethodDeclaration` so
that `MaybeParseAttributes` can find them. This is already how it works
for C parameters hanging off of the selector.
This change alone is insufficient to enable `diagnose_if` for
Objective-C methods and effectively is NFC. There will be a follow-up PR
for diagnose_if. This change is still useful for any other work that may
need attributes to reference Objective-C parameters.
rdar://138596211
GlobalMethodPool is a wrapper around DenseMap that does not add
anything except:
using Lists = std::pair<ObjCMethodList, ObjCMethodList>;
This patch removes the wrapper and switches to an alias with "using".
In ReadMethodPool in ASTReader.cpp, we can simplify:
insert(std::make_pair(Sel, SemaObjC::GlobalMethodPool::Lists()))
to:
try_emplace(Sel)
But then try_emplace(Sel).first->second is the same as operator[], so
this patch simplifies the rest of the function.
GlobalMethodPool, the type of MethodPool, is a type wrapping DenseMap
and exposes only a subset of the DenseMap methods.
This patch adds operator[] to GlobalMethodPool so that we can avoid
repeated hash lookups. I don't bother using references or rvalue
references in operator[] because Selector, the key type, is small and
trivially copyable. Note that Selector is a class that wraps a
PointerUnion.
Attribute `optnone` must turn off all optimizations including fast-math
ones. Actually AST nodes in the 'optnone' function still had fast-math
flags. This change implements fixing FP options before function body is
parsed.
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 patch moves `ObjCMethodDecl::ImplementationControl` to a DeclBase.h so that it's complete at the point where corresponsing bit-field is declared. This patch also converts it to a scoped enum `clang::ObjCImplementationControl`.
Instead of emitting a redefinition error, check that definitions are
equivalent and allow such scenario.
A few non-obvious implementation details:
* to avoid multiple definitions in the redeclaration chain we just drop
the new definition after checking for equivalence;
* for checking definition equivalence use ODR hash instead of
ASTStructuralEquivalence because it avoids excessive recursive
deserialization. Though after detecting a mismatch we do deserialize
multiple entities to provide a better error message.
rdar://82908223
Differential Revision: https://reviews.llvm.org/D124286
This change will allow users to call getNullability() without providing an ASTContext.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D140104
Incorrect `isOverriding` flag triggers the assertion
`!Overridden.empty()` in `ObjCMethodDecl::getOverriddenMethods` when a
method is marked as overriding but we cannot find any overrides.
When a method is declared in a category and defined in implementation,
we don't treat it as an override because it is the same method with
a separate declaration and a definition. But with modules we can find
a method declaration both in a modular category and a non-modular category
with different memory addresses. Thus we erroneously conclude the method
is overriding. Fix by comparing canonical declarations that are the same
for equal entities coming from different modules.
rdar://92845511
Differential Revision: https://reviews.llvm.org/D138630
When during parsing we encountered a duplicate `ObjCProtocolDecl`, we
were always emitting an error. With this change we accept
* when a previous `ObjCProtocolDecl` is in a hidden [sub]module;
* parsed `ObjCProtocolDecl` is the same as the previous one.
And in case of mismatches we provide more detailed error messages.
rdar://93069080
Differential Revision: https://reviews.llvm.org/D130327
I went over the output of the following mess of a command:
(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z |
parallel --xargs -0 cat | aspell list --mode=none --ignore-case |
grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n |
grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)
and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).
Differential Revision: https://reviews.llvm.org/D130827
For backwards compatiblity, we emit only a warning instead of an error if the
attribute is one of the existing type attributes that we have historically
allowed to "slide" to the `DeclSpec` just as if it had been specified in GNU
syntax. (We will call these "legacy type attributes" below.)
The high-level changes that achieve this are:
- We introduce a new field `Declarator::DeclarationAttrs` (with appropriate
accessors) to store C++11 attributes occurring in the attribute-specifier-seq
at the beginning of a simple-declaration (and other similar declarations).
Previously, these attributes were placed on the `DeclSpec`, which made it
impossible to reconstruct later on whether the attributes had in fact been
placed on the decl-specifier-seq or ahead of the declaration.
- In the parser, we propgate declaration attributes and decl-specifier-seq
attributes separately until we can place them in
`Declarator::DeclarationAttrs` or `DeclSpec::Attrs`, respectively.
- In `ProcessDeclAttributes()`, in addition to processing declarator attributes,
we now also process the attributes from `Declarator::DeclarationAttrs` (except
if they are legacy type attributes).
- In `ConvertDeclSpecToType()`, in addition to processing `DeclSpec` attributes,
we also process any legacy type attributes that occur in
`Declarator::DeclarationAttrs` (and emit a warning).
- We make `ProcessDeclAttribute` emit an error if it sees any non-declaration
attributes in C++11 syntax, except in the following cases:
- If it is being called for attributes on a `DeclSpec` or `DeclaratorChunk`
- If the attribute is a legacy type attribute (in which case we only emit
a warning)
The standard justifies treating attributes at the beginning of a
simple-declaration and attributes after a declarator-id the same. Here are some
relevant parts of the standard:
- The attribute-specifier-seq at the beginning of a simple-declaration
"appertains to each of the entities declared by the declarators of the
init-declarator-list" (https://eel.is/c++draft/dcl.dcl#dcl.pre-3)
- "In the declaration for an entity, attributes appertaining to that entity can
appear at the start of the declaration and after the declarator-id for that
declaration." (https://eel.is/c++draft/dcl.dcl#dcl.pre-note-2)
- "The optional attribute-specifier-seq following a declarator-id appertains to
the entity that is declared."
(https://eel.is/c++draft/dcl.dcl#dcl.meaning.general-1)
The standard contains similar wording to that for a simple-declaration in other
similar types of declarations, for example:
- "The optional attribute-specifier-seq in a parameter-declaration appertains to
the parameter." (https://eel.is/c++draft/dcl.fct#3)
- "The optional attribute-specifier-seq in an exception-declaration appertains
to the parameter of the catch clause" (https://eel.is/c++draft/except.pre#1)
The new behavior is tested both on the newly added type attribute
`annotate_type`, for which we emit errors, and for the legacy type attribute
`address_space` (chosen somewhat randomly from the various legacy type
attributes), for which we emit warnings.
Depends On D111548
Reviewed By: aaron.ballman, rsmith
Differential Revision: https://reviews.llvm.org/D126061
This refactor changes the GlobalMethodPool to a class that contains
the DenseMap of methods. This is to allow for the addition of a
separate DenseSet in a follow-up diff that will handle method
de-duplication when inserting methods into the global method pool.
Changes:
- the `GlobalMethods` pair becomes `GlobalMethodPool::Lists`
- the `GlobalMethodPool` becomes a class containing the `DenseMap` of methods
- pass through methods are added to maintain most of the existing code without changing `MethodPool` -> `MethodPool.Methods` everywhere
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D109898
Programmers would like to be able to test direct methods by calling them from a
different linkage unit or mocking them, both of which are impossible. This
patch adds a flag that effectively disables the attribute, which will fix this
when enabled in testable builds. rdar://71190891
Differential revision: https://reviews.llvm.org/D95845