This is exactly like copy_addr except that it is not viewed from the verifiers
perspective as an "invalid" copy of a move only value. It is intended to be used
in two contexts:
1. When the move checker emits a diagnostic since it could not eliminate a copy,
we still need to produce valid SIL without copy_addr on move only types since we
will hit canonical SIL eventually even if we don't actually codegen the SIL. The
pass can just convert said copy_addr to explicit_copy_addr and everyone is
happy.
2. To implement the explicit copy function for address only types.
The effect of declaring an import `@_weakLinked` is to treat every declaration from the module as if it were declared with `@_weakLinked`. This is useful in environments where entire modules may not be present at runtime. Although it is already possible to instruct the linker to weakly link an entire dylib, a Swift attribute provides a way to declare intent in source code and also opens the door to diagnostics and other compiler behaviors that depend on knowing that all the module's symbols will be weakly linked.
rdar://96098097
We had two notions of canonical types, one is the structural property
where it doesn't contain sugared types, the other one where it does
not contain reducible type parameters with respect to a generic
signature.
Rename the second one to a 'reduced type'.
`int_trap` doesn't provide a failure message, which makes crash reports hard to understand.
This is mostly the case for optimized casts which fail.
rdar://97681511
Snapshots are copies of a function at a given point in time.
Currently it's only used for running passes repeatedly for performance profiling.
In future it can be used for caching when doing lazy evaluation in the pipeline.
Andy some time ago already created the new API but didn't go through and update
the old occurences. I did that in this PR and then deprecated the old API. The
tree is clean, so I could just remove it, but I decided to be nicer to
downstream people by deprecating it first.
This is just the very beginning... I still need to implement more parts of
SILGen for this. But all great things start small. I am going to iterate on top
of this and just wanted to get some initial parts of the work in as I go.
I also created a SILType::isMoveOnly() helper that returns true if a type is
a move only wrapped type or a first class move only type. The verifier check
that move only types aren't copied in canonical SIL was rewired to use that as well.
The new utility, given an phi, visits all adjacent phis (i.e. arguments
to the same block) which are (potentially iterated) reborrows of a value
reaching the given phi.
Specifically this means that rather than always being owned, we now have owned
and guaranteed versions of copyable_to_moveonlywrapper. Similar to
moveonlywrapper_to_copyable, one chooses which variant one gets by using
specific SILBuilder APIs:
create{Owned,Guaranteed}CopyableToMoveOnlyWrapperValueInst. It is still
forwarding and the rest of the forwarding APIs work as expected except that the
forwarding ownership is fixed (and an assertion will result if one attempts to
do so).
NOTE: It is assumed that trivial operands are always passed to the owned
variant.
non-throwing functions.
Activating swift-functions-errors tests
Inserting macros and additional parameters in C and C++ functions following the pattern to lowering to LLVM IR.
If such declarations have availability conditions they have to be
kept alive until IRGen to emit opaque type descriptor that is going
be used at runtime to determine the underlying type.
This is important for "optimized" mode only because in non-optimized
mode "shared" symbol survives SILGen.
It's used to implement `InstructionSet` and `ValueSet`: sets of SILValues and SILInstructions.
Just like `BasicBlockSet` for basic blocks, the set is implemented by setting bits directly in SILNode.
This is super efficient because insertion and deletion to/from the set are basic bit operations.
The cost is an additional word in SILNode. But this is basically negligible: it just adds ~0.7% of memory used for SILInstructions.
In my experiments, I didn't see any relevant changes in memory consumption or compile time.
