When activating a union member, none of the unions in that path can have
a non-trivial constructor. Unfortunately, this is something we have to
do when evaluating the bytecode, not while compiling it.
Save them as a pointer intead of using a shared_ptr. This we we can use
the pointer integer value to differentiate the "no initmap yet" and "all
values initialzed" cases.
This regresses one test case in const-eval.c, but as it turns out, that
only worked coincidentally before.
Instead of checking the initial callee, check the callee after the
virtual dispatch. This means we need to check whether we're in a ctor to
not regress existing tests.
Fixes https://github.com/llvm/llvm-project/issues/165234
We used to do this the other way around to work around an awkwardness
with CheckStore, namely that we shouldn't check pointers for being
activated when activating them.
Add a parameter to CheckStore instead and call CheckStore() _before_
activating and initializing the pointers in the respective opcode
implementations.
Fixes https://github.com/llvm/llvm-project/issues/164975
Fixes#152893.
An assert was raised when a constexpr virtual function was called from
an constexpr array element with -fexperimental-new-constant-interpreter
set.
In the attached test case, the global variable later only points to
gargbage, because the MaterializeTemporaryExpr used to initialize it is
a local variable, which is gone by the time we try to evaluate the
store.
Fixes#156223
This breaks a ton of libc++ tests otherwise, since calling
std::destroy_at will currently end the lifetime of the entire array not
just the given element.
See https://github.com/llvm/llvm-project/issues/147528
This way, we can check a single uint8_t for != 0 to know whether this
block is accessible or not. If not, we still need to figure out why not
and diagnose appropriately of course.
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
I forgot to call this here as well. It was only used in the EvalEmitter
implementation of the function. Also fix a problem where we didn't
diagnose out-of-lifetime reads here.
For mutable and const fields, we have two bits in InlineDescriptor,
which both get inherited down the hierarchy. When a field is both const
and mutable, we CAN read from it if it is a mutable-in-const field, but
we _can't_ read from it if it is a const-in-mutable field. We need
another bit to distinguish the two cases.
Only activate things if the syntactical structure suggests so. This adds
a bunch of new opcodes to control whether to activate in stores, etc.
Fixes#134789
