Continuing work from #18344, be more conservative about when we load
SwiftOnoneSupport. Specifically, -emit-silgen and -emit-sibgen, despite
not going through the SIL Optimizer, may silently introduce dependencies
on SwiftOnoneSupport.
Because we want to support the ability to posthumously compile SILGen
and SIBGen'd files with these implicit dependencies, and because SIL
is not yet capable of expressing the dependency itself, we must always
assume we need to load SwiftOnoneSupport.
This patch adds SIL-level debug info support for variables whose
static type is rewritten by an optimizer transformation. When a
function is (generic-)specialized or inlined, the static types of
inlined variables my change as they are remapped into the generic
environment of the inlined call site. With this patch all inlined
SILDebugScopes that point to functions with a generic signature are
recursively rewritten to point to clones of the original function with
new unique mangled names. The new mangled names consist of the old
mangled names plus the new substituions, similar (or exactly,
respectively) to how generic specialization is handled.
On libSwiftCore.dylib (x86_64), this yields a 17% increase in unique
source vars and a ~24% increase in variables with a debug location.
rdar://problem/28859432
rdar://problem/34526036
There are three modes of concern here:
1) User provides -vfsoverlay but not -Xcc -ivfsoverlay
Recommended behavior.
2) User provides -Xcc -ivfsoverlay but not -vfsoverlay
Legacy behavior. Clang will handle setup for the VFS.
3) User provides both -vfsoverlay and -Xcc -ivfsoverlay
Unsupported. We will ignore the clang VFS overlays and substitute our
own. We will also pop a warning about this.
One use case is using DenseSet to manage a set of source locations, so that we
emit at most one compiler diagnostic per location (see
https://github.com/apple/swift/pull/18402).
Add an abstraction to retrieve a name suitable for display for a given
source location for use with diagnostics, debug locations, and magic
file literals.
Adds the -vfsoverlay frontend option that enables the user to pass
VFS overlay YAML files to Swift. These files define a (potentially
many-layered) virtual mapping on which we predicate a VFS.
Switch all input-based memory buffer reads in the Frontend to the new
FileSystem-based approach.
We previously shied away from this in order to not /accidentally/
depend on it, but it becomes interesting again with textual
interfaces, which can certainly be read by humans. The cross-file
order is the order of input files, which is at least controllable by
users.
NSObject.hashValue is provided to satisfy the hashValue constraint of
the Hashable protocol. However, it is not the correct customization
point for interoperating with Objective-C, because Objective-C code
will call through the -hash method. Warn about overrides of
NSObject.hashValue; users should override NSObject.hash instead.
Fixes rdar://problem/42780635.
ClassDecl::getSuperclass() produces a complete interface type describing the
superclass of a class, including any generic arguments (for a generic type).
Most callers only need the referenced ClassDecl, which is (now) cheaper
to compute: switch those callers over to ClassDecl::getSuperclassDecl().
Fixes an existing test for SR-5993.
Introduce three new requests for name lookup operations that avoid performing
type checking/semantic analysis. They work using syntactic information
(e.g., TypeReprs) and AST-level name lookup operations that will (eventually)
avoid and calls back into type checking. The new requests are:
* Retrieve the superclass declaration of a protocol or class declaration. Use
this request for ClassDecl::getSuperclassDecl() and
ProtocolDecl::getSuperclassDecl().
* Retrieve the types “directly referenced” by a particular location in
an inheritance clause. This query is based on looking at the TypeReprs
and performing fairly-minimal lookup, so it does not involve any Type
computations.
* Retrieve the types “directly referenced” by the underlying type of
a typealias. This query allows us to desugar a typealias without forming
a type.
Along with these is a core operation to transform a set of TypeDecl*s
into a set of NominalTypeDecl*s, looking through typealiases, and
without involving Type at all. The superclass-decl request does this
to find a ClassDecl; other requests will eventually do this to (e.g.)
find all of the protocols mentioned in an inheritance clause.
Switch a number of callers of the Type-based lookupQualified() over to
the newer (and preferred) declaration-based lookupQualified(). These are
the easy ones; NFC.
This commit does not modify those APIs or their usage. It just:
1. Moves the APIs onto SILFunctionBuilder and makes SILFunctionBuilder a friend
of SILModule.
2. Hides the APIs on SILModule so all users need to use SILFunctionBuilder to
create/destroy functions.
I am doing this in order to allow for adding/removing function notifications to
be enforced via the type system in the SILOptimizer. In the process of finishing
off CallerAnalysis for FSO, I discovered that we were not doing this everywhere
we need to. After considering various other options such as:
1. Verifying after all passes that the notifications were sent correctly and
asserting. Turned out to be expensive.
2. Putting a callback in SILModule. This would add an unnecessary virtual call.
I realized that by using a builder we can:
1. Enforce that users of SILFunctionBuilder can only construct composed function
builders by making the composed function builder's friends of
SILFunctionBuilder (notice I did not use the word subclass, I am talking
about a pure composition).
2. Refactor a huge amount of code in SILOpt/SILGen that involve function
creation onto a SILGenFunctionBuilder/SILOptFunctionBuilder struct. Many of
the SILFunction creation code in question are straight up copies of each
other with small variations. A builder would be a great way to simplify that
code.
3. Reduce the size of SILModule.cpp by 25% from ~30k -> ~23k making the whole
file easier to read.
NOTE: In this commit, I do not hide the constructor of SILFunctionBuilder since
I have not created the derived builder structs yet. Once I have created those in
a subsequent commit, I will hide that constructor.
rdar://42301529
Having the parent nodes available when building children is
sometimes useful, as I'll show soon. It also naturally avoids the
weird re-use of local variables in this function that made it so
delightfully difficult to read.
SwiftOnoneSupport is an implicit dependency of no-opt builds that is usually
only loaded when frontend actions that emit optimization-sensitive outputs are
run.
Force the implicit dependency to be explicit when -track-system-dependencies is
used in concert with frontend actions that requires SIL passes be run.
