To make this change, we have to use `lookup` instead of `operator[]` on
a map. They both return the same thing: a default constructed value. The
difference is that `lookup` default constructs a value and then returns
it, whereas `operator[]` default constructs a value, inserts it into the
map, and then returns a reference to that. Given that we are using a
by-value return, the only way this is different is if a later use of the
map depends on a value being at that key.
The map is a private variable of the class, so the only possible users
are are other member functions. The only other use of the map that cares
about the contents of the map is in `lookupInBases`, and it accesses the
map with `operator[]`. This means that attempting to access the same
element in this function will default construct the value before doing
anything with it, which means it would do the exact thing it needs to do
in the case where we are looking up a non-existent key, therefore no
behavior has changed.
In terms of performance, this would either be a win or neutral. The
benefit is that in some cases, we can avoid a memory allocation just
read the contents of a 32-bit `0`. If a call to `isAmbiguous` is always
followed up with a call to `lookupInBases`, then we allocate the memory
just a little bit later for no difference in performance.
This reintroduces `Type.h`, having earlier been renamed to `TypeBase.h`,
as a redirection to `TypeBase.h`, and redirects most users to include
the former instead.
This is a preparatory patch for being able to provide inline definitions
for `Type` methods which would otherwise cause a circular dependency
with `Decl{,CXX}.h`.
Doing these operations into their own NFC patch helps the git rename
detection logic work, preserving the history.
This patch makes clang just a little slower to build (~0.17%), just
because it makes more code indirectly include `DeclCXX.h`.
This is a preparatory patch, to be able to provide inline definitions
for `Type` functions which depend on `Decl{,CXX}.h`. As the latter also
depends on `Type.h`, this would not be possible without some
reorganizing.
Splitting this rename into its own patch allows git to track this as a
rename, and preserve all git history, and not force any code
reformatting.
A later NFC patch will reintroduce `Type.h` as redirection to
`TypeBase.h`, rewriting most places back to directly including `Type.h`
instead of `TypeBase.h`, leaving only a handful of places where this is
necessary.
Then yet a later patch will exploit this by making more stuff inline.
This changes a bunch of places which use getAs<TagType>, including
derived types, just to obtain the tag definition.
This is preparation for #155028, offloading all the changes that PR used
to introduce which don't depend on any new helpers.
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.
This function has been superseded by
HeuristicResolver::lookupDependentName(), which implements the same
heuristics and more.
Porting note for any out-of-tree callers:
```
RD->lookupDependentName(Name, Filter);
```
can be replaced with:
```
HeuristicResolver(RD->getASTContext())->lookupDependentName(Name, Filter);
```
An assertion failure occurs in Clang when attempting to compile such an
example:
```c++
template <typename, typename, bool> struct MozPromise {
class Private;
private:
int mMagic4 = 42;
};
template <typename ResolveValueT, typename RejectValueT, bool IsExclusive>
struct MozPromise<ResolveValueT, RejectValueT, IsExclusive>::Private : MozPromise {
void SetTaskPriority() { mMagic4 ; }
};
```
Output:
```
clang: llvm-project/llvm/include/llvm/Support/Casting.h:566: decltype(auto) llvm::cast(const From&) [with To = clang::RecordType; From = clang::QualType]: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.
```
The reason is in the incorrect way of casting types when searching for
names in base classes
```c++
return Specifier->getType()->castAs<RecordType>()->getDecl()->getCanonicalDecl() == BaseRecord;
```
It loses injected types for template class names.
This patch provides fix for such cases
Unlike the previous version
(https://github.com/llvm/llvm-project/pull/114978), this patch also
removes an unnecessary assert that causes Clang to crash when compiling
such tests. (clang/lib/AST/DeclCXX.cpp)
https://lab.llvm.org/buildbot/#/builders/52/builds/4021
```c++
template <class T>
class X {
public:
X() = default;
virtual ~X() = default;
virtual int foo(int x, int y, T &entry) = 0;
void bar() {
struct Y : public X<T> {
Y() : X() {}
int foo(int, int, T &) override {
return 42;
}
};
}
};
```
the assertions:
```c++
llvm-project/clang/lib/AST/DeclCXX.cpp:2508: void clang::CXXMethodDecl::addOverriddenMethod(const CXXMethodDecl *): Assertion `!MD->getParent()->isDependentContext() && "Can't add an overridden method to a class template!"' failed.
```
I believe that this assert is unnecessary and contradicts the logic of
this patch. After its removal, Clang was successfully built using
itself, and all tests passed.
Currently the following example is a compilation failure:
```cpp
template<typename T> struct A {
typedef int M;
struct B {
typedef void M;
struct C;
};
};
template<typename T> struct A<T>::B::C : A<T> {
M m; // void or int ?
};
```
According to the point 13.8.3.2
```
A dependent base class is a base class that is a dependent type and is not the current instantiation.
Note 2 : A base class can be the current instantiation in the case of a nested class naming an enclosing class as a base.
```
The base class `A` is the current instantiation, because `C` is a nested
class for an enclosing class `A<T>`, it's is the not-dependent base
class and we need to search the names through its scope.
This patch makes this example compile
Here I'm splitting up the existing "if" statement into two. Mixing
hasDefinition() and insert() in one "if" condition would be extremely
confusing as hasDefinition() doesn't change anything while insert()
does.
This patch includes the commit 01adf96ebc86 and a fix of unhandled declaration
references.
When looking up base classes, Clang first checks whether a base class is a
template and takes the specialized template based on it. However, the base class
might be instantiated, and the above behavior can lose information.
This patch fixes the problem by first checking whether a base class is a record
declaration, so the instantiated one will be taken.
Differential Revision: https://reviews.llvm.org/D143840
D137531 had once fixed the issue. However, it caused a crash during compiling
llvm/unittests/IR/PatternMatch.cpp in stage-2. The reason is the predicator
isDerivedFrom does not consider independent types if the derived type is
dependent.
This patch improves D137531 by adding an option to make isDerivedFrom consider
independent types.
Differential Revision: https://reviews.llvm.org/D142437
The idiom:
```
DeclContext::lookup_result R = DeclContext::lookup(Name);
for (auto *D : R) {...}
```
is not safe when in the loop body we trigger deserialization from an AST file.
The deserialization can insert new declarations in the StoredDeclsList whose
underlying type is a vector. When the vector decides to reallocate its storage
the pointer we hold becomes invalid.
This patch replaces a SmallVector with an singly-linked list. The current
approach stores a SmallVector<NamedDecl*, 4> which is around 8 pointers.
The linked list is 3, 5, or 7. We do better in terms of memory usage for small
cases (and worse in terms of locality -- the linked list entries won't be near
each other, but will be near their corresponding declarations, and we were going
to fetch those memory pages anyway). For larger cases: the vector uses a
doubling strategy for reallocation, so will generally be between half-full and
full. Let's say it's 75% full on average, so there's N * 4/3 + 4 pointers' worth
of space allocated currently and will be 2N pointers with the linked list. So we
break even when there are N=6 entries and slightly lose in terms of memory usage
after that. We suspect that's still a win on average.
Thanks to @rsmith!
Differential revision: https://reviews.llvm.org/D91524
caller.
This function did not satisfy its documented contract: it only
considered the first lookup result on each base path, not all lookup
results. It also performed unnecessary memory allocations.
This change results in a minor change to our representation: we now
include overridden methods that are found by any derived-to-base path
(not involving another override) in the list of overridden methods for a
function, rather than filtering out functions from bases that are both
direct virtual bases and indirect virtual bases for which the indirect
virtual base path contains another override for the function. (That
filtering rule is part of the class-scope name lookup rules, and doesn't
really have much to do with enumerating overridden methods.) The users
of the list of overridden methods do not appear to rely on this
filtering having happened, and it's simpler to not do it.
This is partly in preparation for an upcoming change that can change the
order in which DeclContext lookup results are presented.
In passing, fix some obvious errors where name lookup's notion of a
"static member function" missed static member function templates, and
where its notion of "same set of declarations" was confused by the same
declarations appearing in a different order.
Summary:
Apparently all users of the function were fine with short-circuiting
and none cared to override the default argument.
Reviewers: aaron.ballman, rsmith
Reviewed By: aaron.ballman
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D75319
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368942
This patch implements parsing and sema for "omp declare mapper"
directive. User defined mapper, i.e., declare mapper directive, is a new
feature in OpenMP 5.0. It is introduced to extend existing map clauses
for the purpose of simplifying the copy of complex data structures
between host and device (i.e., deep copy). An example is shown below:
struct S { int len; int *d; };
#pragma omp declare mapper(struct S s) map(s, s.d[0:s.len]) // Memory region that d points to is also mapped using this mapper.
Contributed-by: Lingda Li <lildmh@gmail.com>
Differential Revision: https://reviews.llvm.org/D56326
llvm-svn: 352906
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
1. Pack std::pair<bool, unsigned> in CXXBasePaths::ClassSubobjects.
2. Use a SmallPtrSet instead of a SmallDenseSet for CXXBasePaths::VisitedDependentRecords.
3. Reorder some members of CXXBasePaths to save 8 bytes.
4. Use a SmallSetVector instead of a SetVector in CXXBasePaths::ComputeDeclsFound to avoid some allocations.
This speeds up an -fsyntax-only on all of Boost by approx 0.15%,
mainly by speeding up CXXBasePaths::lookupInBases by
approx 10%. No functional changes.
Patch by Bruno Ricci!
Differential Revision: https://reviews.llvm.org/D49302
llvm-svn: 337607
This is similar to the LLVM change https://reviews.llvm.org/D46290.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46320
llvm-svn: 331834
So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.
Because of the volume of changes, I explicitly avoided making any change
that wasn't highly local and obviously correct to me (e.g. we still have
a number of foo(cast<Bar>(baz)) that I didn't touch, since overloading
is a thing and the cast<Bar> did actually change the type -- just up the
class hierarchy).
I also tried to leave the types we were cast<>ing to somewhere nearby,
in cases where it wasn't locally obvious what we were dealing with
before.
llvm-svn: 326416
looking up a dependent name in a record that derives from itself
rdar://32273000
Differential Revision: https://reviews.llvm.org/D33324
llvm-svn: 303366
This commit implements basic support for indexing of dependent declaration
references. Now the indexer tries to find a suitable match in the base template
for a dependent member ref/decl ref/dependent type.
rdar://29158210
Differential Revision: https://reviews.llvm.org/D32972
llvm-svn: 302632
This reversal is being done with r267453's author's (i.e. Richard Smith's) permission.
This fixes https://llvm.org/bugs/show_bug.cgi?id=27601
Also, per Richard's request the examples from the bug report have been added to our test suite.
llvm-svn: 270016
Add parsing, sema analysis and serialization/deserialization for 'declare reduction' construct.
User-defined reductions are defined as
#pragma omp declare reduction( reduction-identifier : typename-list : combiner ) [initializer ( initializer-expr )]
These custom reductions may be used in 'reduction' clauses of OpenMP constructs. The combiner specifies how partial results can be combined into a single value. The
combiner can use the special variable identifiers omp_in and omp_out that are of the type of the variables being reduced with this reduction-identifier. Each of them will
denote one of the values to be combined before executing the combiner. It is assumed that the special omp_out identifier will refer to the storage that holds the resulting
combined value after executing the combiner.
As the initializer-expr value of a user-defined reduction is not known a priori the initializer-clause can be used to specify one. Then the contents of the initializer-clause
will be used as the initializer for private copies of reduction list items where the omp_priv identifier will refer to the storage to be initialized. The special identifier
omp_orig can also appear in the initializer-clause and it will refer to the storage of the original variable to be reduced.
Differential Revision: http://reviews.llvm.org/D11182
llvm-svn: 262582
Maybe this and the NumDeclsFound member should just be a std::vector
instead. (it could be a std::dynarray, but that missed standardization)
llvm-svn: 245392
This lets us pass functors (and lambdas) without void * tricks. On the
downside we can't pass CXXRecordDecl's Find* members (which are now type
safe) to lookupInBases directly, but a lambda trampoline is a small
price to pay. No functionality change intended.
llvm-svn: 243217
