Handles #123121
This patch updates `note_constexpr_invalid_cast` diagnostic to use
`enum_select` instead of `select,` improving readability and reducing
reliance on magic numbers in caller sites.
getRecord() returns null on array elements, even for composite arrays.
The assertion here was overly restrictive and having an array element as
instance pointer should be fine otherwise.
Use the regular code paths for interpreting.
Add new instructions: `StartSpeculation` will reset the diagnostics
pointers to `nullptr`, which will keep us from reporting any diagnostics
during speculation. `EndSpeculation` will undo this.
The rest depends on what `Emitter` we use.
For `EvalEmitter`, we have no bytecode, so we implement `speculate()` by
simply visiting the first argument of `__builtin_constant_p`. If the
evaluation fails, we push a `0` on the stack, otherwise a `1`.
For `ByteCodeEmitter`, add another instrucion called `BCP`, that
interprets all the instructions following it until the next
`EndSpeculation` instruction. If any of those instructions fails, we
jump to the `EndLabel`, which brings us right before the
`EndSpeculation`. We then push the result on the stack.
For `new A[N]{1,2,3}`, we need to allocate N elements of type A, and
initialize the first three with the given InitListExpr elements.
However, if N is larger than 3, we need to initialize the remaining
elements with the InitListExpr array filler.
Similarly, for `new A[N];`, we need to initilize all fields with the
constructor of A. The initializer type is a CXXConstructExpr of
IncompleteArrayType in this case, which we can't generally handle.
Make lifetime management more explicit. We're only using this for
CXXPseudoDestructorExprs for now but we need this to handle
std::construct_at/placement-new after destructor calls later anyway.
Instead of heap-allocating it. This is similar to what the current
interpeter does. In C, we have no function calls, so the extra heap
allocation never makes sense.
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.
Add it as another kind of pointer, saving both a `Type*` for the result
of the typeid() expression as well as one for the type of the typeid
expression.
In certain cases (i.e. long double on x86), the bit with we get from the
floating point semantics is different than the type size we compute for
the BitCast instruction. Pass this along to DoBitCast, so in there we
can check only the relevant bits for being initialized.
This also fixes a weirdness we still had in DoBitCast.
This is unneeded in almost all circumstances. We only return an APValue
back to clang when the evaluation is finished, and that is always done
by an EvalEmitter - which has its own implementation of the Ret
instructions.
This is a subset of #68288, with hopefully narrower scope. It does not
support bitcasting to non-integral types yet.
Bitfields are supported, but only if they result in a full byte-sized
final buffer. It does not support casting from null-pointers yet or
casting from indeterminate bits.
The tests are from #68288 and partially from #74775.
The `BitcastBuffer` struct is currently always working in single bits,
but I plan to (try to) optimize this for the common full-byte case.
... tried their initializer already. In that case, diagnose the
non-const initializer instead of the reference to a non-constexpr
variable later. This is used in a lot of openmp tests.
The global scope we create when evaluating expressions might free some
of the dynamic memory allocations, so we can't check for memory leaks
before destroying it.
