- Implement SILGen for conditional multi-pattern PBD's.
- Have the type checker check where clauses on PBDs.
- Change the AST to represent complex if/let PBD's with
composed PBDs instead of breaking them down. For example,
represent:
if let x? = foo(), y? = bar() where x == y {
as a single PBD in a StmtCondition instead of representing
it as three entries in the condition.
The later change is good for AST/source fidelity as well as providing
a cheap way to exercise all the logic I'm building.
Swift SVN r26959
Previously some parts of the compiler referred to them as "fields",
and most referred to them as "elements". Use the more generic 'elements'
nomenclature because that's what we refer to other things in the compiler
(e.g. the elements of a bracestmt).
At the same time, make the API better by providing "getElement" consistently
and using it, instead of getElements()[i].
NFC.
Swift SVN r26894
(containing just an uncond branch) when a shared block isn't actually shared.
This is a revised version of r26676 that makes sure to emit the cleanups for a
case pattern as soon as possible. Extending the lifetime of the case value
across the body of the switch caused extra copies of COW types.
Swift SVN r26685
This patch introduces a new kind of pattern for matching bool literals, i.e. true and false. Essentially, it is very similar to a pattern for matching enum elements, but simpler. Most of the code is just a boiler plate code copy/pasted from the code for enum element patterns. The only different thing is the emitBoolDispatch function, which emits a SIL code for matching bools.
With this patch, we don't get any false non-exhaustive switch diagnostics for switches on bools anymore. And we have a lot of radars complaining about it. For example rdar://16514545 and rdar://20130240.
Note, that this patch fixes the non-exhaustive switch diagnostics without changing the internal representation of bools. Implementing bool as an enum would have the same effect when it comes to these diagnostics and we would get this diagnostics fix for free, i.e. without any code committed here. But implementing bools-as-enums is an ongoing work and I'm investigating its performance implications. If we become confident that bool-as-enum does not have a negative impact on performance and decide to merge it, then we can revert this patch as it would not be necessary anymore. But if we decide to skip the enum-as-bool approach to its performance issues, then we would have at least fixed the false non-exhaustive diagnostics for bools by means of this patch.
Swift SVN r26650
This change permits SILGen to make smarter decisions about
block placement by keeping related blocks together instead
of always inserting to the end to the function. The
flipside is that SILGen needs to be somewhat careful to
create blocks in the right order. Counter-intuitively,
that order is the reverse of the order in which the blocks
should be laid out, since blocks created later will be
inserted before blocks created earlier. Note, however,
that this produces the right results for recursive
emission.
To that end, adjust a couple of places in SILGen to
create blocks in properly nested order.
All of the block-order differences in the tests seem
to be desirable; several of them even had confused
comments wondering how on earth a block got injected
where it did.
Also, fix the implementation of SILBuilder::moveBlockTo,
and fix a latent bug in epilogue emission where epilogBB
was erased from its parent (deleting it) and then
queried multiple times (!).
Swift SVN r26428
This patch also introduces some SILGen infrastructure for
dividing the function into "ordinary" and "postmatter"
sections, with error-handling-like stuff going into the
final section. Currently, this is largely undermined by
SILBuilder, but I'm going to fix that in a follow-up.
Swift SVN r26422
Previously, a multi-pattern var/let decl like:
var x = 4, y = 17
would produce two pattern binding decls (one for x=4 one for y=17). This is convenient
in some ways, but is bad for source reproducibility from the ASTs (see, e.g. the improvements
in test/IDE/structure.swift and test/decl/inherit/initializer.swift).
The hardest part of this change was to get parseDeclVar to set up the AST in a way
compatible with our existing assumptions. I ended up with an approach that forms PBDs in
more erroneous cases than before. One downside of this is that we now produce a spurious
"type annotation missing in pattern"
diagnostic in some cases. I'll take care of that in a follow-on patch.
Swift SVN r26224
This changes 'if let' conditions to take general refutable patterns, instead of
taking a irrefutable pattern and implicitly matching against an optional.
Where before you might have written:
if let x = foo() {
you now need to write:
if let x? = foo() {
The upshot of this is that you can write anything in an 'if let' that you can
write in a 'case let' in a switch statement, which is pretty general.
To aid with migration, this special cases certain really common patterns like
the above (and any other irrefutable cases, like "if let (a,b) = foo()", and
tells you where to insert the ?. It also special cases type annotations like
"if let x : AnyObject = " since they are no longer allowed.
For transitional purposes, I have intentionally downgraded the most common
diagnostic into a warning instead of an error. This means that you'll get:
t.swift:26:10: warning: condition requires a refutable pattern match; did you mean to match an optional?
if let a = f() {
^
?
I think this is important to stage in, because this is a pretty significant
source breaking change and not everyone internally may want to deal with it
at the same time. I filed 20166013 to remember to upgrade this to an error.
In addition to being a nice user feature, this is a nice cleanup of the guts
of the compiler, since it eliminates the "isConditional()" bit from
PatternBindingDecl, along with the special case logic in the compiler to handle
it (which variously added and removed Optional around these things).
Swift SVN r26150
in terms of the pattern binding/emission facilities that are currently
used for switches. They are more general (handling all patterns,
not hacked up just for optionals).
This leads to us producing better code for if/let bindings, because we
don't alloc_stack a temporary and deal with memory for non-address-only
types (e.g. the common case of an optional pointer). Instead, the code
emits a select_enum{_addr} on the value.
While this changes the generated code in the compiler, there is no exposed
behavioral change to the developer.
Swift SVN r26142
"similar", avoiding false positive "not exhaustive" diagnostics on switches
like:
switch ... {
case let x?: break
case .None: break
}
Also, start using x? patterns in the stdlib more (review appreciated!), which
is what shook this issue out.
Swift SVN r26004
This introduces a new pattern, spelled "x?" which is sugar for
matching ".Some(x)". It also changes the parser slightly so that
_ (the discard expr) is parsed as a unary expr instead of as an
expr. This allows it to have postfix ? after it, which is important
in pattern contexts to support "case _?:".
Swift SVN r25907
This adds the -profile-coverage-mapping option to swift, and teaches
SILGenProfiling to generate mappings from source ranges to counters.
Swift SVN r25266
Curried function parameters (i.e., those past the first written
parameter list) default to having argument labels (which they always
have), but any attempt to change or remove the argument labels would
fail. Use the fact that we keep both the argument labels and the
parameter names in patterns to generalize our handling of argument
labels to address this problem.
The IDE changes are due to some positive fallout from this change: we
were using the body parameters as labels in code completions for
subscript operations, which was annoying and wrong.
Fixes rdar://problem/17237268.
Swift SVN r24525
them in a more consistent and principled way. Two changes here: MUI is generated
when a vardecl is emitted, not as a separate "MarkPatternUninitialized" pass. Second,
when generating a MUI for self parameters with a temporary alloc_stack (due to the
possibility of superclass remapping of self) emit the MUI on the allocation itself,
not on the incoming argument. This is a lot more consistent (dissolving a bunch of
hacks in DI).
In terms of behavior changes, this only changes the raw sil generated by SILGen and
consumed by DI, so there is no user-visible change. This simply unblocks future work.
Swift SVN r23823
Change the SILLocations for enum element dispatches to make the line table
more consistent. emitEnumElementDispatch may be invoked several times so
it should use the location of the first pattern rather than TheSwitch.
Swift SVN r22782
This reverts commit r22739 because it broke an unreachable code test
and is blocking the bots.
The problem can be reproduced with:
swift -frontend -disable-objc-attr-requires-foundation-module -emit-sil test/SILPasses/unreachable_code.swift -o /dev/null -verify
Swift SVN r22750
more consistent. emitEnumElementDispatch may be invoked several times so
it should use the location of the first pattern rather than TheSwitch.
Swift SVN r22739
There are a lot of different ways to interpret the
"kind" of an access. This enum specifically dictates
the semantic rules for an access: direct-to-storage
and direct-to-accessor accesses may be semantically
different from ordinary accesses, e.g. if there are
observers or overrides.
Swift SVN r22290
Use this in calls to TypeBase::getTypeOfMember() that were relying on
archetypes solely because they were using EnumElementDecl::getArgumentType().
Swift SVN r22205
Specialization now recurses on only that prefix of the
current matrix which shares a specialization form
(essentially, a pattern kind) with the head row. This is
inferior to the previous algorithm in a number of ways: we
may require more switches to perform a single dispatch, and
we may introduce more redundant variables in the leaves.
However, it also means that we will have fully specialized a
row along exactly one path in the decision tree, which makes
it much easier to work with dispatches that introduce new
cleanups.
This change also changes switch-dispatch to use the new
dynamic-cast instructions.
Incidentally fixes rdar://16401831.
Swift SVN r19336
When we specialize the decision matrix on a pattern, we have to start with the *first* preceding wildcard, not the last. Oops. While we're here, clean things up a bit by using Optional instead of magic integer values to track the first wildcard row. Fixes <rdar://problem/17272985>.
Swift SVN r19061
Allow a form of 'case is T' that matches the cast result to a subpattern, 'case <pattern> as T'. This exposes an issue in switch destructuring with casting into complex class hierarchies <rdar://problem/16401831> but works for common cases.
Swift SVN r15396
