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
accessors.
Optimize these accessors by making them check for
BoundGenericXType instead of BoundGenericType and dyn_cast'ing
the Decl. (The latter used to be necessary before we split
BoundGenericType.)
Swift SVN r15037
associating the store to it with the first CaseStmt.
The goal is to make the linetable entries as monotone as possible.
Fixes <rdar://problem/15888936> switch line table's first line misplaced.
Swift SVN r13805
If all of the bindings in a pattern column are 'let' bindings, don't box the binding. If there is any 'var' in the column, conservatively fall back to binding a box. Factor out the logic for producing an initialization for a variable into an new emitInitializationForVarDecl method that SILGenPattern can use. Add a 'copyInto' method to RValue that can bind a copy of an rvalue to an Initialization.
This doesn't use Chris's new +0 ManagedValue optimization yet, so we end up with an extra copy_value when the value is bound that might still be avoidable.
Swift SVN r12903
Don't crash when sugary pattern nodes like Paren and Var get mixed and we try to cast subpatterns to the expected semantic pattern type.
Swift SVN r12674
use the new RValue emission infrastructure instead of duplicating
some of it. This enables the use of computed properties, fixing
<rdar://problem/15859432> SILGen abort when pattern matching on computed property
and eliminates some code that future changes would otherwise have to
worry about.
There are other problems with this code (e.g. see rdar://15863069), so I think
we should disable the feature until it has time to really bake, but this is still
useful progress in the right direction and is a net reduction of code.
Swift SVN r12618
with two kinds, and some more specific predicates that clients can use.
The notion of 'computed or not' isn't specific enough for how properties
are accessed. We already have problems with ObjC properties that are
stored but usually accessed through getters and setters, and a bool here
isn't helping matters.
NFC.
Swift SVN r12593
Thanks to the way we've set up our diagnostics engine, there's not actually
a reason for /everything/ to get rebuilt when /one/ diagnostic changes.
I've split them up into five categories for now: Parse, Sema, SIL, IRGen,
and Frontend, plus a set of "Common" diagnostics that are used in multiple
areas of the compiler. We can massage this later.
No functionality change, but should speed up compile times!
Swift SVN r12438
Split 'destructive_switch_enum_addr' into separate 'switch_enum_addr' and 'take_enum_data_addr' instructions. This should unblock some optimization work we would like to do with enums.
Swift SVN r12015
