- Fix an off-by-one error when a fix-it continues onto a newline
- Don't print multi-line insertions inline due to poor UX
- When printing multi-line fix-its out of line attached to a message,
replace newlines with the carriage return emoji
- Don't underline a line's leading whitespace unless it's part of an insertion
The only reason why BranchPropagatedUser existed was because early on in SIL, we
weren't sure if cond_br should be able to handle non-trivial values in
ossa. Now, we have reached the point where we have enough experience to make the
judgement that it is not worth having in the representation due to it not
holding its weight.
Now that in ToT we have banned cond_br from having non-trivial operands in ossa,
I can just eliminate BranchPropagatedUser and replace it with the operands that
we used to construct them!
A few notes:
1. Part of my motiviation in doing this is that I want to change LiveRange to
store operands instead of instructions. This is because we are interested in
being able to understand the LiveRange at a use granularity in cases where we
have multiple operands. While doing this, I discovered that I needed
SILInstructions to use the Linear Lifetime Checker. Then I realized that now was
the time to just unwind BranchPropagatedUser.
2. In certain places in SemanticARCOpts, I had to do add some extra copies to
transform arrays of instructions from LiveRange into their operand form. I am
going to remove them in a subsequent commit when I change LiveRange to work on
operands. I am doing this split to be incremental.
3. I changed isSingleInitAllocStack to have an out array of Operand *. The only
user of this code is today in SemanticARCOpts and this information is fed to the
Linear Lifetime Checker, so I needed to do it.
We previously computed cross-imports by comparing N transitive imports against N transitive imports. This is wasteful, because at least one of the two modules in a pair has to actually declare a cross-import overlay for us to discover one, and the vast majority of modules don’t declare any.
This commit makes us instead compare N transitive imports against M transitive imports which are known to declare at least one cross-import overlay. Since N is potentailly in the thousands while M is perhaps in the double digits, this should be good for a substantial time savings.
However, this optimization has made a test of another cross-import performance optimization fail—not because we have regressed on that, but because it skips work the test case expects us to perform. I have XFAILed that test for now.
Fixes <rdar://problem/59538458>.
Previously, we just banned cond_br from having non-trivial operands along
critical edges. This is a stronger condition that beyond simplifying ossa for
passes, also lets me remove the need for BranchPropagatedUser, simplifying the
linear lifetime checker.
There were a couple of methods in LangOptions and some related ones in
Availability and ASTContext that were added more recently.
Refactor the three older checks to the newer scheme.
OwnershipUtils.h is growing a bit and I want to use it to store abstract higher
level utilities for working with ossa. LinearLifetimeChecker is just a low level
detail of that, so it makes sense to move it out now.
doesn't conform to the associatedtype's protocol (only in diagnostic mode).
This allows the solver to find solutions for more cases involving requirement
failures for dependent member types without special cases across the solver
that check for dependent member types with no type variables.
Augment the `isSingleRetainablePointer` check that allows IRGen to avoid adding branching around retain/release operations on enums that use the null pointer extra inhabitant with a more general "can value witness extra inhabitants" method on TypeInfo, which says whether a type's retain/release operations are safe to invoke on some or all of its extra inhabitants. This lets us generalize the optimization to include things like `String?` or `ClassProtocol?` which are common types with a nullable pointer in them.
- consistently operate on the address value of the variable via
stripAccessMarkers. Never use address of the transient access which
may not have sufficient lifetime.
- Recognize begin_access [read] as a load.
- delete dead access markers after deleting copies
Fixes <rdar://59345115> Unnecessary copy_addr not eliminated with
exclusivity checking
This is in prepration for other bug fixes.
Clarify the SIL utilities that return canonical address values for
formal access given the address used by some memory operation:
- stripAccessMarkers
- getAddressAccess
- getAccessedAddress
These are closely related to the code in MemAccessUtils.
Make sure passes use these utilities consistently so that
optimizations aren't defeated by normal variations in SIL patterns.
Create an isLetAddress() utility alongside these basic utilities to
make sure it is used consistently with the address corresponding to
formal access. When this query is used inconsistently, it defeats
optimization. It can also cause correctness bugs because some
optimizations assume that 'let' initialization is only performed on a
unique address value.
Functional changes to Memory Behavior:
- An instruction with side effects now conservatively still has side
effects even when the queried value is a 'let'. Let values are
certainly sensitive to side effects, such as the parent object being
deallocated.
- Return the correct MemBehavior for begin/end_access markers.
The normal type checking of switch statements checks the switch subject
first, without context, then evaluates the cases. Introduce a one-way
constraint into the type checking of switch statements within function
builders to provide this same behavior. The difference can be observed
in code such as:
enum E {
case a
case b(Int, String?)
}
enum E2 {
case b(Int, String?)
}
func getSomeEnumOverloaded(_: Double) -> E { return .a }
func getSomeEnumOverloaded(_: Int) -> E2 { return .b(0, nil) }
func f() {
switch getSomeEnumOverloaded(17) {
case .a: // error: no member named "a" in E2
print("a")
default:
print("default")
}
}
When the subject expression `getSomeEnumOverloaded(17)` is resolved
without consider cases, it will select the second
`getSomeEnumOverloaded(_:)`, because the literal 17 prefers to be
an `Int`. The type checking of the first case would then fail because E2
does not contain a member named "a".
Prior to this change, the same expression within a function
builder would succeed in type checking, because the lack of case named
"a" within "E2" would make the second getSomeEnumOverloaded() unusable.
Making this code work by considering the cases along with the subject
expression is not unreasonable, and may be the right long term
direction for the language. However, it's a feature that should be
discussed separately, and the semantics should agree between function
builders and normal statements.
Big thanks to John McCall for noting the missing one-way constraint!
* [Diagnostics] Experimental diagnostic printing updates
This new style directly annotates small snippets of code with
error messages, highlights and fix-its. It also uses color more
effectively to highlight important segments.
* [Diagnostics] Stage educational notes and experimental formatting behind separate frontend flags
educational notes -> -enable-educational-notes
formatting -> -enable-experimental-diagnostic-formatting
* [Diagnostics] Refactor expensive line lookups in diag formatting
* [Diagnostics] Refactor some PrintingDiagnosticConsumer code into a flush method
* [Diag-Experimental-Formatting] Custom formatting for Xcode editor placeholders
* [Diag-Experimental-Formatting] Better and more consistent textual description of fix its
* [Diags-Experimental-Formatting] Handle lines with tab characters correctly when rendering highlights and messages
Tabs are converted to 2 spaces for display purposes.
* [Diag-Experimental-Formatting] Refactor byte-to-column mapping for efficiency
* [Diag-Experimental-Formatting] Fix line number indent calculation
* [Diag-Experimental-Formatting] Include indicators of insertions and deletions in the highlight line
Inserts are underlined by green '+' chars, deletions by red '-' chars.
* [Diag-Experimental-Formatting] Change color of indicator arrow for non-ASCII anchored messages
* [Diag-experimental-formatting] Make tests less sensitive to line numbering
* [Diag-Experimental-Formatting] Update tests to allow windows path separators
* [Diag-Experimental-Formatting] Bug fixes for the integrated REPL
