When iterator consists of tuple of variable and iteration only mutates
the tuple partially, improve the warning message from "changing to 'let"
to "changing the pattern to '(..., case let, ...)"
Rather than walking into the inactive regions of IfConfigDecls looking for
references to a declaration before we diagnose it, go to the syntax
tree and look through inactive *and unparsed* regions for identifier
tokens that match. If we find one, suppress the diagnostic.
This reduces our dependency on IfConfigDecl in the AST, and also makes
the same suppression work with code in unparsed regions that had no
representation in IfConfigDecl.
Today, the reported source range of a GuardStmtScope is just that of
the statement itself, ending after the 'else' block. Similarly, a
PatternEntryDeclScope ends immediately after the initializer
expression.
Since these scopes introduce names until the end of the parent
BraceStmt (meaning they change the insertion point), we were
relying on the addition of child scopes to extend the source
range.
While we still need the hack for extending source ranges to deal
with string interpolation, at least in the other cases we can
get rid of it.
Note that this fixes a bug where a GuardStmtScope would end
before an inactive '#if' block if the inactive '#if' block was
the last element of a BraceStmt.
The VDUC was missing a class of AST nodes that can bind variables:
patterns in switch statements. For these, it was falling back to
requesting a simple replacement of the bound variable name with _. But
for patterns, this means there's a two-step dance the user has to go
through where the first fixit does this:
.pattern(let x) -> .pattern(let _)
Then a second round of compilation would emit a fixit to do this:
.pattern(let _) -> .pattern(_)
Instead, detect "simple" variable bindings - for now, variable patterns
that are immediately preceded by a `let` or `var` binding pattern - and
collapse two steps into one.
Resolves rdar://47240768
We used to take all the captures of a local function and treat them all
as read and write usages of vars from an outer scope. Instead, let's
refactor the analysis to walk into local functions.
Instead, check them and their error handling right away.
In addition to fixing the crash in the radar, this also causes
us to emit unused variable warnings in functions containing
local functions.
Eventually, TC.definedFunctions should go away altogether.
Fixes <rdar://problem/53956342>.
The main fixes here are:
- we weren't looking through open-existentials in the l-value
- we weren't handling mutating gets correctly unless CSApply wrapped
the base in an InOutExpr, which seems to be multifile-sensitive
- we were missing diagnostics in some cases involving subscripts
A better fix would be to re-introduce LValueAccessKind, but I wanted
a workable short-term fix that I could try to get into 5.1.
Fixes rdar://49482742, which is specific to the lazy-getter problem.
The diagnostics for `variable_never_mutated` always suggests
changing `var` to `let`, which is misleading in case of
for-each loops where explicitly immutable context applies.
This patch adds some variety to the message to make it appropriate.
Resolves: SR-9732
Using the attribute in this position is a relic from the Swift 2
days, and fixing it required letting invalid code fall through to
Sema instead of being diagnosed in Parse proper. Treat 'var'
in this position like 'let' by simply offering to remove it
instead of extracting it into a separate variable.
Instead of doing that, suggest removing 'var' altogether because
'let' cannot be used directly in an implicitly immutable context.
Resolves: rdar://problem/32390726
The variable_never_used fixit transforms into invalid code in the case of two-stage let initialization. I introduced a new diagnostic that does not fixit and suggests removing the value.
Implements SE-0055: https://github.com/apple/swift-evolution/blob/master/proposals/0055-optional-unsafe-pointers.md
- Add NULL as an extra inhabitant of Builtin.RawPointer (currently
hardcoded to 0 rather than being target-dependent).
- Import non-object pointers as Optional/IUO when nullable/null_unspecified
(like everything else).
- Change the type checker's *-to-pointer conversions to handle a layer of
optional.
- Use 'AutoreleasingUnsafeMutablePointer<NSError?>?' as the type of error
parameters exported to Objective-C.
- Drop NilLiteralConvertible conformance for all pointer types.
- Update the standard library and then all the tests.
I've decided to leave this commit only updating existing tests; any new
tests will come in the following commits. (That may mean some additional
implementation work to follow.)
The other major piece that's missing here is migration. I'm hoping we get
a lot of that with Swift 1.1's work for optional object references, but
I still need to investigate.
- Fix SR-1112, where the fixit would eat all characters in the RHS expression except for the last one due to improper SourceRange math.
- Noticed by inspection, an expression undergoing an implicit conversion (such as a load from an optional `var`) would be judged as requiring parens, when that's really unnecessary.
Revert "Make function parameters and refutable patterns always
immutable"
This reverts commit 8f2fbdc93a.
Once we have finally merged master into the Swift 2.2 branch to be, we
should revert this commit to turn the errors back on for Swift 3.0.
When we see an unused variable in a simple-enough "if/let" (also guard and
while of course), fixit it into a comparison against nil instead of replacing
the name of the variable with "_". Also special case initialization with an
as? expression, since we can transform that into an "is" boolean test.
All refutable patterns and function parameters marked with 'var'
is now an error.
- Using explicit 'let' keyword on function parameters causes a warning.
- Don't suggest making function parameters mutable
- Remove uses in the standard library
- Update tests
rdar://problem/23378003
Make the following illegal:
switch thing {
case .A(var x):
modify(x0
}
And provide a replacement 'var' -> 'let' fix-it.
rdar://problem/23172698
Swift SVN r32883
Make the following patterns illegal:
if var x = ... {
...
}
guard var x = ... else {
...
}
while var x = ... {
...
}
And provide a replacement fixit 'var' -> 'let'.
rdar://problem/23172698
Swift SVN r32855
