Following classes provide symbol mangling for specific purposes:
*) Mangler: the base mangler class, just providing some basic utilities
*) ASTMangler: for mangling AST declarations
*) SpecializationMangler: to be used in the optimizer for mangling specialized function names
*) IRGenMangler: mangling all kind of symbols in IRGen
All those classes are not used yet, so it’s basically a NFC.
Another change is that some demangler node types are added (either because they were missing or the new demangler needs them).
Those new nodes also need to be handled in the old demangler, but this should also be a NFC as those nodes are not created by the old demangler.
My plan is to keep the old and new mangling implementation in parallel for some time. After that we can remove the old mangler.
Currently the new implementation is scoped in the NewMangling namespace. This namespace should be renamed after the old mangler is removed.
This was already done for getSuccessorBlocks() to distinguish getting successor
blocks from getting the full list of SILSuccessors via getSuccessors(). This
commit just makes all of the successor/predecessor code follow that naming
convention.
Some examples:
getSingleSuccessor() => getSingleSuccessorBlock().
isSuccessor() => isSuccessorBlock().
getPreds() => getPredecessorBlocks().
Really, IMO, we should consider renaming SILSuccessor to a more verbose name so
that it is clear that it is more of an internal detail of SILBasicBlock's
implementation rather than something that one should consider as apart of one's
mental model of the IR when one really wants to be thinking about predecessor
and successor blocks. But that is not what this commit is trying to change, it
is just trying to eliminate a bit of technical debt by making the naming
conventions here consistent.
Before this commit all code relating to handling arguments in SILBasicBlock had
somewhere in the name BB. This is redundant given that the class's name is
already SILBasicBlock. This commit drops those names.
Some examples:
getBBArg() => getArgument()
BBArgList => ArgumentList
bbarg_begin() => args_begin()
This eliminates all inline creation of SILBasicBlock via placement new.
There are a few reasons to do this:
1. A SILBasicBlock is always created with a parent function. This commit
formalizes this into the SILBasicBlock API by only allowing for SILFunctions to
create SILBasicBlocks. This is implemented via the type system by making all
SILBasicBlock constructors private. Since SILFunction is a friend of
SILBasicBlock, SILFunction can still create a SILBasicBlock without issue.
2. Since all SILBasicBlocks will be created in only a few functions, it becomes
very easy to determine using instruments the amount of memory being allocated
for SILBasicBlocks by simply inverting the call tree in Allocations.
With LTO+PGO, normal inlining can occur if profitable so there shouldn't be
overhead that we care about in shipping compilers.
The witness thunks for default witnesses are different from the
witness thunks for normal witnesses, because default witnesses take
'Self' (the whole conforming type) rather than having it substituted
away. Cope with this difference while still substituting the innermost
generic parameters for a generic requirement.
Reimplement the witness matching logic used for generic requirements
so that it properly models the expectations required of the witness,
then captures the results in the AST. The new approach has a number of
advantages over the existing hacks:
* The constraint solver no longer requires hacks to try to tangle
together the innermost archetypes from the requirement with the
outer archetypes of the context of the protocol
conformance. Instead, we create a synthetic set of archetypes that
describes the requirement as it should be matched against
witnesses. This eliminates the infamous 'SelfTypeVar' hack.
* The type checker no longer records substitutions involving a weird
mix of archetypes from different contexts (see above), so it's
actually plausible to reason about the substitutions of a witness. A
new `Witness` class contains the declaration, substitutions, and all
other information required to interpret the witness.
* SILGen now uses the substitution information for witnesses when
building witness thunks, rather than computing all of it from
scratch. ``substSelfTypeIntoProtocolRequirementType()` is now gone
(absorbed into the type checker, and improved from there), and the
witness-thunk emission code is simpler. A few other bits of SILGen
got simpler because the substitutions can now be trusted.
* Witness matching and thunk generation involving generic requirements
and nested generics now works, based on some work @slavapestov was
already doing in this area.
* The AST verifier can now verify the archetypes that occur in witness substitutions.
* Although it's not in this commit, the `Witness` structure is
suitable for complete (de-)serialization, unlike the weird mix of
archetypes previously present.
Fixes rdar://problem/24079818 and cleans up an area that's been messy
and poorly understood for a very, very long time.
Today, loads and stores are treated as having @unowned(unsafe) ownership
semantics. This leaves the user to specify ownership changes on the loaded or
stored value independently of the load/store by inserting ARC operations. With
the change to Semantic SIL, this will no longer be true. Instead loads, stores
have ownership semantics that one must reason about such as copy, take, and
trivial.
This change moves us closer to that world by eliminating the default
OwnershipQualification argument from create{Load,Store}. This means that the
compiler developer cannot ignore reasoning about the ownership semantics of the
memory operation that they are creating.
Operationally, this is a NFC change since I have just gone through the compiler
and updated all places where we create loads, stores to pass in the former
default argument ({Load,Store}OwnershipQualifier::Unqualified), to
SILBuilder::create{Load,Store}(...). For now, one can just do that in situations
where one needs to create loads/stores, but over time, I am going to tighten the
semantics up via the verifier.
rdar://28685236
We don't want the machine calling conventions for closure invocation functions to necessarily be tied to the convention for normal thin functions or methods. NFC yet; for now, 'closure' follows the same behavior as the 'method' convention, but as part of partial_apply simplification it will be a requirement that partial_apply takes a @convention(closure) function and a box and produces a @convention(thick) function from them.
- Move the common performance inliner functionality into PerformanceInlinerUtils.cpp.
- Move the functionality specific to non-generic inlining into NonGenericPerformanceInliner.cpp
- Temporarily disable the inlining of generics. It will be enabled in the subsequent commit.
id-as-Any lets you pass Optional to an ObjC API that takes `nonnull id`, and also lets you bridge containers of `Optional` to `NSArray` etc. When this occurs, we can unwrap the value and bridge it so that inhabited optionals still pass into ObjC in the expected way, but we need something to represent `none` other than the `nil` pointer. Cocoa provides `NSNull` as the canonical "null for containers" object, which is the least bad of many possible answers. If we happen to have the rare nested optional `T??`, there is no precedented analog for these in Cocoa, so just generate a unique sentinel object to preserve the `nil`-ness depth so we at least don't lose information round-tripping across the ObjC-Swift bridge.
Making Optional conform to _ObjectiveCBridgeable is more or less enough to make this all work, though there are a few additional edge case things that need to be fixed up. We don't want to accept `AnyObject??` as an @objc-compatible type, so special-case Optional in `getForeignRepresentable`.
Implements SR-0140 (rdar://problem/27905315).
The new instructions are: ref_tail_addr, tail_addr and a new attribute [ tail_elems ] for alloc_ref.
For details see docs/SIL.rst
As these new instructions are not generated so far, this is a NFC.
id-as-Any lets you pass Optional to an ObjC API that takes `nonnull id`, and also lets you bridge containers of `Optional` to `NSArray` etc. When this occurs, we can unwrap the value and bridge it so that inhabited optionals still pass into ObjC in the expected way, but we need something to represent `none` other than the `nil` pointer. Cocoa provides `NSNull` as the canonical "null for containers" object, which is the least bad of many possible answers. If we happen to have the rare nested optional `T??`, there is no precedented analog for these in Cocoa, so just generate a unique sentinel object to preserve the `nil`-ness depth so we at least don't lose information round-tripping across the ObjC-Swift bridge.
Making Optional conform to _ObjectiveCBridgeable is more or less enough to make this all work, though there are a few additional edge case things that need to be fixed up. We don't want to accept `AnyObject??` as an @objc-compatible type, so special-case Optional in `getForeignRepresentable`.
Implements SR-0140 (rdar://problem/27905315).
The new instructions are: ref_tail_addr, tail_addr and a new attribute [ tail_elems ] for alloc_ref.
For details see docs/SIL.rst
As these new instructions are not generated so far, this is a NFC.
When applying substitutions to substitution lists in SIL, we would
unpack the ArrayRef<Substitution> into a SubstitutionMap on each
iteration over the original ArrayRef<Substitution>. Discourage
this sort of thing by removing the API in question and refactoring
surrounding code.
