The new instruction is needed for opaque values mode to allow values to
be extracted from tuples containing packs which will appear for example
as function arguments.
The new instruction wraps a value in a `@sil_weak` box and produces an
owned value. It is only legal in opaque values mode and is transformed
by `AddressLowering` to `store_weak`.
The new instruction unwraps an `@sil_weak` box and produces an owned
value. It is only legal in opaque values mode and is transformed by
`AddressLowering` to `load_weak`.
This is a futile attempt to discourage future use of getType() by
giving it a "scary" name.
We want people to use getInterfaceType() like with the other decl kinds.
It is necessary for opaque values where for casts that will newly start
out as checked_cast_brs and be lowered to checked_cast_addr_brs, since
the latter has the source formal type, IRGen relies on being able to
access it, and there's no way in general to obtain the source formal
type from the source lowered type.
The `bare` attribute indicates that the object header is not used throughout the lifetime of the value.
This means, no reference counting operations are performed on the object and its metadata is not used.
The header of bare objects doesn't need to be initialized.
The `bare` attribute indicates that the object header is not used throughout the lifetime of the object.
This means, no reference counting operations are performed on the object and its metadata is not used.
The header of bare objects doesn't need to be initialized.
Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
Properties that are marked as initialized are printed as `[assign=<index>]`
where `<index>` point to the property position in `getInitializedProperties()`
list.
This instruction is similar to AssignByWrapperInst, but instead of having
a destination operand, the initialization is fully factored into the init
function operand. Like AssignByWrapper, AssignOrInit has partial application
operands of both the initializer and the setter, and DI will lower the
instruction to a call based on whether the assignment is initialization or
a setter call.
Just the $*T -> $*@moveOnly T variant for addresses. Unlike the object version
this acts like a cast rather than something that provides semantics from the
frontend to the optimizer.
The reason why I am using a different instruction for addresses and objects here
is that the object checker doesnt have to deal with things like initialization.
The new alloc_pack_metadata and dealloc_pack_metadata are inserted as
part of IRGen lowering. The former indicates that the next instruction
might result in on-stack pack metadata being emitted. The latter
indicates that this is the position at which metadata emitted on behalf
of its operand should be cleaned up.
* Add @_used and @_section attributes for global variables and top-level functions
This adds:
- @_used attribute that flags as a global variable or a top-level function as
"do not dead-strip" via llvm.used, roughly the equivalent of
__attribute__((used)) in C/C++.
- @_section("...") attribute that places a global variable or a top-level
function into a section with that name, roughly the equivalent of
__attribute__((section("..."))) in C/C++.
"reborrow" flag on the SILArgument avoids transitive walk over the phi operandsi
to determine if it is a reborrow in multiple utilities.
SIL transforms must keep the flag up-to-date by calling SILArgument::setReborrow.
SILVerifier checks to ensure the flag is not invalidated.
Currently "escaping" is not used anywhere.
Optimizations can rely on alias analysis to know that an in-argument (or parts of it) is not actually read.
We have to do the same in the verifier: if alias analysis says that an in-argument is not read, there is no need that the memory location is initialized.
Fixes a false verifier error.
rdar://106806899
This patch replaces the stateful generation of SILScope information in
SILGenFunction with data derived from the ASTScope hierarchy, which should be
100% in sync with the scopes needed for local variables. The goal is to
eliminate the surprising effects that the stack of cleanup operations can have
on the current state of SILBuilder leading to a fully deterministic (in the
sense of: predictible by a human) association of SILDebugScopes with
SILInstructions. The patch also eliminates the need to many workarounds. There
are still some accomodations for several Sema transformation passes such as
ResultBuilders, which don't correctly update the source locations when moving
around nodes. If these were implemented as macros, this problem would disappear.
This necessary rewrite of the macro scope handling included in this patch also
adds proper support nested macro expansions.
This fixes
rdar://88274783
and either fixes or at least partially addresses the following:
rdar://89252827
rdar://105186946
rdar://105757810
rdar://105997826
rdar://105102288
This is used to teach the checker that the thing being checked is supposed to be
uninitialized at the mark_must_check point so that we don't put a destroy_addr
there.
The way this is implemented is that we always initially add
assignable_but_not_consumable but in DI once we discover that the assign we are
guarding is an init, we convert the assignable to its initable variant.
rdar://106525988
This still does not have the complete behavior that we want since we are not yet
inserting the debug_value undef to invalidate after performing moves.
NOTE: In printed SIL, I decided to make the flag implicit if we have a
noncopyable type. This is just to reduce the bloat in SIL. If one needs this
property for a copyable type though, it is mandatory.
This is in preparation for wiring up debug info support for noncopyable
values. Originally this flag name made sense since it was set when we performed
consume operator checking. Now I am going to use it for noncopyable types as
well. I think the new name uses_moveable_value_debuginfo actually describes what
the flag is supposed to do, tell IRGen that the value may be moved since it
needs to use moveable value debug info emission.
Provide ASTWalker with a customization point to specify whether to
check macro arguments (which are type checked but never emitted), the
macro expansion (which is the result of applying the macro and is
actually emitted into the source), or both. Provide answers for the
~115 different ASTWalker visitors throughout the code base.
Fixes rdar://104042945, which concerns checking of effects in
macro arguments---which we shouldn't do.
This is used to model global_addr/ref_element_addr/escaping closure captures
where we do not want to allow the user to consume the memory (leaving the memory
in a potentially uninitialized state), but we do want to allow for the user to
assign over the memory all at once.
Consider a situation like the following:
```
@_moveOnly
struct FileDescriptor {
var state: CInt = ...
}
final class Klass {
var descriptor = ...
}
func consumeDescriptor(_ x: __owned FileDescriptor) {}
// Eventually both of these will point at the same class.
var globalKlass = ...
var globalKlass2 = ...
func memoryUnsafe() {
consumeDescriptor(globalKlass.descriptor)
consumeDescriptor(globalKlass2.descriptor)
}
func callMemoryUnsafe() {
globalKlass2 = globalKlass()
memoryUnsafe()
}
```
Notice how in the above in memoryUnsafe, locally the compiler has no way of
knowing that globalKlass and globalKlass2 actually point at the same class and
thus we are attempting to consume the same descriptor twice. This is even
allowed by exclusivity. If descriptor was not move only, this would be safe
since we would just copy the value when we consume it. But b/c we ar3e using
move only, we must take from the memory.
This fits the name of the check better. The reason I am doing this renaming is
b/c I am going to add a nonconsumable but assignable check for
global_addr/ref_element_addr/captures with var semantics.
