This PR contains the final work to convert the compiler to +0. There are still some tests failing, but I would like to get start performing PR testing of the branch.

This changes the python interpreter used to invoke the tests to Python3. Python2 has been EOL'ed by the Python Software Foundation. This migration enables the Swift test suite to run with Python 3 instead.

Replace this paragraph with a description of your changes and rationale. Provide links to external references/discussions if appropriate.

Resolves SR-NNNN.

An initial implementation of a more resilient 2-word representation for String. It uses BridgeObject (for now) to achieve a high degree of resilience. In the future, we'll add more small string forms, establish UnsafeString, and generally rejigger String's views to be properly layered on top.

Notes:

• Self slices are currently implemented by forming _NSContiguousStrings to hold the sliced up _StringCore. This incurs overhead. Long term, we could support owned self slices, but for now it would be fruitful to try to eliminate all uses of self-slicing _StringCore from the stdlib. The most common occurrence (but by no means the only) is through _ephemeralString. Instead, for anything that can't possibly escape, we should convert to an UnsafeString, guarantee the lifetime, and slice that up.

• We cannot utilize small representations effectively until we start to wean ourselves off of _LegacyStringCore. Ideally (depending on project planning needs) we would be fully weaned off before adding small representations. We'd also like to get close to performance parity where it matters prior, to better gauge the impact of such optimizations.

• The spiritual predecessor to this effort is at https://github.com/dabrahams/swift/commits/string-recore, and while the physical implementation differs, that's a great demonstration of what we're trying to accomplish.

This pull request changes the diagnostic error thrown when a string interpolation isn't closed by a parenthesis properly (ie: let x = "g \(")

Previously, it would blurt out unterminated string literal, with these changes it'll instead throw expected ')' at end of string interpolation

When generic metadata for a class is requested in the same module where the class is defined, rather than a call to the generic metadata accessor or to a variant of typeForMangledNode, a call to a new accessor--a canonical specialized generic metadata accessor--is emitted. The new function is defined schematically as follows:

    MetadataResponse `canonical specialized metadata accessor for C<K>`(MetadataRequest request) {
      (void)`canonical specialized metadata accessor for superclass(C<K>)`(::Complete)
      (void)`canonical specialized metadata accessor for generic_argument_class(C<K>, 1)`(::Complete)
      ...
      (void)`canonical specialized metadata accessor for generic_argument_class(C<K>, count)`(::Complete)
      auto *metadata = objc_opt_self(`canonical specialized metadata for C<K>`);
      return {metadata, MetadataState::Complete};
    }

To enable these new canonical specialized generic metadata accessors, metadata for generic classes is prespecialized as needed. So are the metaclasses and the corresponding rodata.

Previously, the lazy objc naming hook was registered during process execution when the first generic class metadata was instantiated. Since that instantiation may occur "before process launch" (i.e. if the generic metadata is prespecialized), the lazy naming hook is now installed at process launch.

A problem that we have to deal with when calling C++ constructors is that the ABI of a C++ constructor depends not only on the signature of the constructor but on the class on which it is defined. For example, it can be necessary to pass additional “implicit” arguments to constructors of virtual base classes.

It is therefore fundamentally not possible for SignatureExpansion (which doesn’t have access to the CXXConstructorDecl) to reliably produce the correct LLVM signature from only the type of the constructor. The approach we take is to try to get most of the way in SignatureExpansion by marking the SIL function return type with the @out attribute, representing the fact that C++ constructors take a this points to the object to be initialized.

This produces an “assumed” constructor ABI in SignatureExpansion that assumes there are no implicit arguments and that the return type of the constructor ABI is void (and indeed there is no way to represent anything else in the SIL type). If this assumed ABI doesn’t match the actual ABI, we insert a thunk in IRGen.

The thunk is marked alwaysinline, so it doesn’t incur any runtime overhead, but some compile-time overhead is required for LLVM to inline the thunk. If this turns out to be excessive, we can introduce what is essentially a peephole optimization for a full apply of a function_refthat refers to a C++ constructor and directly emit the constructor call in this case (along with any required implicit arguments) instead of calling the thunk. I’ve chosen not to tackle that in this PR though as it’s already large enough.

On some ABIs (e.g. Itanium x64), we get lucky and the ABI for a complete constructor call always matches the assumed ABI.

In addition to the core C++ constructor functionality, this PR adds some a couple of small required features:

• Conversion of thin to a Clang void type
• Handling of formal indirect results in SignatureExpansion::expandExternalSignatureTypes()

Add in small strings, plumb all APIs through, etc. There's some current performance issues, namely that small string support introduces branching and our default implementation technique involves spilling to the stack and calling _UnmanagedString methods. The first is unavoidable (although we're planning a better overall branching strategy to reduce this impact), the second is TODO.

This PR migrates instance member on type and type member on instance diagnostics handling to use the new diagnostics framework (fixes) and create more reliable and accurate diagnostics in such scenarios.

From: https://forums.swift.org/t/hacking-equatable-conformance-on-void/25975

The tests right now are kind of lackluster, what else can I be testing with this? What else can be improved upon in this implementation? Is there an edge case that I hadn't thought about?

cc: @jckarter @rjmccall

| | | |------------------|-----------------| |Previous ID | SR-381 | |Radar | None | |Original Reporter | @lhoward | |Type | New Feature | |Status | Closed | |Resolution | Done |

blocks:

• SR-377 Implement NSKeyed[Un]Archiver

relates to:

• SR-412 Linux: Cannot define C function pointer that returns metaclass

Issue Description:

This may be useful to implement NSStringFromClass()-compatible behaviour which is necessary in order to implement NSKeyedArchiver. I am using the attached workaround at the moment but obviously it is very fragile.

Implements apple/swift-evolution#904.

This is the implementation of the string interpolation rework. It is now feature-complete, but there are still a few things on my to-do list:

• ~~It's performing similarly to the current design overall, although individual benchmarks vary wildly—from 1.80x for StringInterpolationSmall to 0.59x for FloatingPointPrinting_Float_interpolated. (Some of the improvements in tests which have little to do with string interpolation are probably thanks to new overloads of String.init(describing:) I added to preserve source compatibility.) We want it to be faster than the status quo. I haven't dug deeply into this yet, and I'd like a second opinion from the CI.~~

• I'm wondering if it would be useful for DefaultStringInterpolation to become moveonly in the future, and if so, if that could be done without breaking ABI compatibility. @rjmccall, what do you think?

• There are a couple of test failures I'm not sure what to do with:

  • ~~Constraints/rdar42678836.swift was apparently added three days ago and has already had its message change twice. @slavapestov, @xedin, can we pin down what this test ought to do?~~

  • IDE/complete_at_top_level.swift fails because we don't suggest a Void function in a string interpolation. I think that comes from this line, which looks like it's intended to prevent you from completing a Void function where a value is expected, but I'm just guessing at its purpose. Can anyone clear up my confusion and help me figure out what this should be doing? (@nkcsgexi wrote this, but it was years ago.)

@swift-ci Please benchmark

cc @milseman

Motivation

It took me far too long to understand why the compiler was giving me this error (I was quickly trying something a bit less trivial than this example involving async/await, and thought the issue was around the execution context):

@main public struct Scraper
{
    public static func main()
    {
        let data = fetch()     //  Instance member 'fetch' cannot be used on type 'Scraper'
                   ^~~~~
    }
    
    func fetch() -> Data
    {
        return Data()
    }
}

Solution

A more precise wording, something like "Instance method cannot be called from static context", would be much more helpful.

As I'm implementing declaration macros I noticed that decls in any macro expansions (including those of expression macros) won't type check.

Description

Steps to reproduce

public class NestedDeclInExprMacro: ExpressionMacro {
  public static func expansion(
    of macro: MacroExpansionExprSyntax, in context: inout MacroExpansionContext
  ) -> ExprSyntax {
    return """
    { () -> Void in
      struct Foo { }
      return ()
    }
    """
  }
}

@expression macro nestedDeclInExpr: () -> Void = #externalMacro(module: "MacroDefinition", type: "NestedDeclInExprMacro")

func testNestedDeclInExpr() {
  let _: () -> Void = #nestedDeclInExpr
}

This results in the following assertion. That is, when evaluating ParseMembersRequest the lever is always assuming the source is the original source buffer.

Assertion failed: (Loc.Value.getPointer() >= Buffer->getBuffer().begin() && Loc.Value.getPointer() <= Buffer->getBuffer().end() && "Location is not from the specified buffer"), function getLocOffsetInBuffer, file SourceLoc.cpp, line 204.
Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.	Program arguments: ...
1. /Users/rxwei/Development/Swift/swift-source/build/Ninja-ReleaseAssert+swift-DebugAssert/swift-macosx-arm64/lib/swift/host -module-name MacroUser -DTEST_DIAGNOSTICS
2.	Swift version 5.8-dev (LLVM 0d61c0fcb536d14, Swift 3374d9871e3c44b)
3.	Compiling with effective version 4.1.50
4.	While evaluating request TypeCheckSourceFileRequest(source_file "/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift")
5.	While evaluating request TypeCheckFunctionBodyRequest(MacroUser.(file).testNestedDeclInExpr()@/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:94:6)
6.	While type-checking statement at [/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:94:29 - line:96:1] RangeText="{
  let _: () -> Void = #nestedDeclInExpr
"
7.	While type-checking declaration 0x1448dfff8 (at /Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:3)
8.	While type-checking expression at [/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23 - line:95:24] RangeText="#"
9.	While type-checking-target starting at /Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23
10.	While type checking expanded expression macro expression at [macro:nestedDeclInExpr:/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23-95:40:1:1 - line:4:1] RangeText="{ () -> Void in
  struct Foo { }
  return ()
"
11.	While type-checking expression at [macro:nestedDeclInExpr:/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23-95:40:1:1 - line:4:1] RangeText="{ () -> Void in
  struct Foo { }
  return ()
"
12.	While type-checking-target starting at macro:nestedDeclInExpr:/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23-95:40:1:1
13.	While walking into 'Foo' (at macro:nestedDeclInExpr:/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23-95:40:2:3)
14.	While evaluating request ParseMembersRequest(MacroUser.(file).testNestedDeclInExpr().explicit closure [email protected]:nestedDeclInExpr:/Users/rxwei/Development/Swift/swift-source/swift/test/Macros/macro_expand.swift:95:23-95:40:2:10)
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x000000010b41a570 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x000000010b419488 llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x000000010b41abfc SignalHandler(int) + 344
3  libsystem_platform.dylib 0x00000001997e41c4 _sigtramp + 56
4  libsystem_pthread.dylib  0x00000001997b5c38 pthread_kill + 288
5  libsystem_c.dylib        0x00000001996c3b28 abort + 180
6  libsystem_c.dylib        0x00000001996c2e84 err + 0
7  swift-frontend           0x0000000107956f08 swift::SourceManager::getLocOffsetInBuffer(swift::SourceLoc, unsigned int) const + 336
8  swift-frontend           0x0000000106ca4834 swift::Lexer::getBufferPtrForSourceLoc(swift::SourceLoc) const + 56
9  swift-frontend           0x0000000106becb00 swift::Lexer::getStateForBeginningOfTokenLoc(swift::SourceLoc) const + 44
10 swift-frontend           0x0000000106c9b4a8 swift::Parser::getParserPosition(swift::SourceLoc, swift::SourceLoc) + 48
11 swift-frontend           0x0000000106c268cc swift::Parser::parseDeclListDelayed(swift::IterableDeclContext*) + 344
12 swift-frontend           0x0000000106cc046c swift::ParseMembersRequest::evaluate(swift::Evaluator&, swift::IterableDeclContext*) const + 556
13 swift-frontend           0x0000000106cc1a5c swift::FingerprintAndMembers swift::SimpleRequest<swift::ParseMembersRequest, swift::FingerprintAndMembers (swift::IterableDeclContext*), (swift::RequestFlags)2>::callDerived<0ul>(swift::Evaluator&, std::__1::integer_sequence<unsigned long, 0ul>) const + 88
14 swift-frontend           0x0000000106cc18f0 swift::SimpleRequest<swift::ParseMembersRequest, swift::FingerprintAndMembers (swift::IterableDeclContext*), (swift::RequestFlags)2>::evaluateRequest(swift::ParseMembersRequest const&, swift::Evaluator&) + 40
15 swift-frontend           0x00000001073a90a8 llvm::Expected<swift::ParseMembersRequest::OutputType> swift::Evaluator::getResultUncached<swift::ParseMembersRequest>(swift::ParseMembersRequest const&) + 288
16 swift-frontend           0x00000001073a8ebc llvm::Expected<swift::ParseMembersRequest::OutputType> swift::Evaluator::getResultCached<swift::ParseMembersRequest, (void*)0>(swift::ParseMembersRequest const&) + 220
17 swift-frontend           0x00000001073a8b80 llvm::Expected<swift::ParseMembersRequest::OutputType> swift::Evaluator::operator()<swift::ParseMembersRequest, (void*)0>(swift::ParseMembersRequest const&) + 68
18 swift-frontend           0x0000000107396ca0 swift::ParseMembersRequest::OutputType swift::evaluateOrDefault<swift::ParseMembersRequest>(swift::Evaluator&, swift::ParseMembersRequest, swift::ParseMembersRequest::OutputType) + 76
19 swift-frontend           0x0000000107396c28 swift::IterableDeclContext::getParsedMembers() const + 116
20 swift-frontend           0x0000000107396a4c swift::IterableDeclContext::loadAllMembers() const + 84
21 swift-frontend           0x00000001073969d4 swift::IterableDeclContext::getMembers() const + 28
22 swift-frontend           0x0000000106f45f90 (anonymous namespace)::Traversal::visitNominalTypeDecl(swift::NominalTypeDecl*) + 392
23 swift-frontend           0x0000000106f44820 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visitStructDecl(swift::StructDecl*) + 32
24 swift-frontend           0x0000000106f44004 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Decl*) + 240
25 swift-frontend           0x0000000106f43eb4 (anonymous namespace)::Traversal::visit(swift::Decl*) + 60
26 swift-frontend           0x0000000106f43e68 (anonymous namespace)::Traversal::doIt(swift::Decl*)::'lambda'()::operator()() const + 36
27 swift-frontend           0x0000000106f43e34 bool llvm::function_ref<bool ()>::callback_fn<(anonymous namespace)::Traversal::doIt(swift::Decl*)::'lambda'()>(long) + 24
28 swift-frontend           0x00000001078b8420 llvm::function_ref<bool ()>::operator()() const + 32
29 swift-frontend           0x0000000106f3e07c (anonymous namespace)::Traversal::traverse(swift::ASTWalker::PreWalkAction, llvm::function_ref<bool ()>, llvm::function_ref<swift::ASTWalker::PostWalkAction ()>) + 156
30 swift-frontend           0x0000000106f38c68 (anonymous namespace)::Traversal::doIt(swift::Decl*) + 208
31 swift-frontend           0x0000000106f3fe84 (anonymous namespace)::Traversal::visitBraceStmt(swift::BraceStmt*) + 356
32 swift-frontend           0x0000000106f3fa84 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Stmt*) + 96
33 swift-frontend           0x0000000106f3f9c8 (anonymous namespace)::Traversal::visit(swift::Stmt*) + 60
34 swift-frontend           0x0000000106f3f980 (anonymous namespace)::Traversal::doIt(swift::Stmt*)::'lambda'(swift::Stmt*)::operator()(swift::Stmt*) const + 36
35 swift-frontend           0x0000000106f3f950 swift::Stmt* llvm::function_ref<swift::Stmt* (swift::Stmt*)>::callback_fn<(anonymous namespace)::Traversal::doIt(swift::Stmt*)::'lambda'(swift::Stmt*)>(long, swift::Stmt*) + 32
36 swift-frontend           0x0000000106f3f840 llvm::function_ref<swift::Stmt* (swift::Stmt*)>::operator()(swift::Stmt*) const + 40
37 swift-frontend           0x0000000106f3f664 swift::Stmt* (anonymous namespace)::Traversal::traverse<swift::Stmt>(swift::ASTWalker::PreWalkResult<swift::Stmt*>, llvm::function_ref<swift::Stmt* (swift::Stmt*)>, llvm::function_ref<swift::ASTWalker::PostWalkResult<swift::Stmt*> (swift::Stmt*)>) + 360
38 swift-frontend           0x0000000106f38678 (anonymous namespace)::Traversal::doIt(swift::Stmt*) + 144
39 swift-frontend           0x0000000106f3b16c (anonymous namespace)::Traversal::visitClosureExpr(swift::ClosureExpr*) + 248
40 swift-frontend           0x0000000106f397c8 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Expr*) + 976
41 swift-frontend           0x0000000106f3939c (anonymous namespace)::Traversal::visit(swift::Expr*) + 60
42 swift-frontend           0x0000000106f39354 (anonymous namespace)::Traversal::doIt(swift::Expr*)::'lambda'(swift::Expr*)::operator()(swift::Expr*) const + 36
43 swift-frontend           0x0000000106f39324 swift::Expr* llvm::function_ref<swift::Expr* (swift::Expr*)>::callback_fn<(anonymous namespace)::Traversal::doIt(swift::Expr*)::'lambda'(swift::Expr*)>(long, swift::Expr*) + 32
44 swift-frontend           0x00000001074828b0 llvm::function_ref<swift::Expr* (swift::Expr*)>::operator()(swift::Expr*) const + 40
45 swift-frontend           0x0000000106f3910c swift::Expr* (anonymous namespace)::Traversal::traverse<swift::Expr>(swift::ASTWalker::PreWalkResult<swift::Expr*>, llvm::function_ref<swift::Expr* (swift::Expr*)>, llvm::function_ref<swift::ASTWalker::PostWalkResult<swift::Expr*> (swift::Expr*)>) + 360
46 swift-frontend           0x0000000106f38598 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 144
47 swift-frontend           0x0000000106f384c8 swift::Expr::walk(swift::ASTWalker&) + 56
48 swift-frontend           0x000000010619e3cc (anonymous namespace)::ConstraintGenerator::visitClosureExpr(swift::ClosureExpr*) + 192
49 swift-frontend           0x000000010619da94 (anonymous namespace)::ConstraintWalker::walkToExprPre(swift::Expr*) + 612
50 swift-frontend           0x0000000106f38540 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 56
51 swift-frontend           0x0000000106f384c8 swift::Expr::walk(swift::ASTWalker&) + 56
52 swift-frontend           0x000000010619a084 generateConstraintsFor(swift::constraints::ConstraintSystem&, swift::Expr*, swift::DeclContext*) + 88
53 swift-frontend           0x0000000106198dfc swift::constraints::ConstraintSystem::generateConstraints(swift::Expr*, swift::DeclContext*, bool) + 92
54 swift-frontend           0x0000000106198614 swift::constraints::ConstraintSystem::generateConstraints(swift::constraints::SolutionApplicationTarget&, swift::FreeTypeVariableBinding) + 472
55 swift-frontend           0x0000000106243c90 swift::constraints::ConstraintSystem::solveImpl(swift::constraints::SolutionApplicationTarget&, swift::FreeTypeVariableBinding) + 396
56 swift-frontend           0x0000000106243474 swift::constraints::ConstraintSystem::solve(swift::constraints::SolutionApplicationTarget&, swift::FreeTypeVariableBinding) + 224
57 swift-frontend           0x00000001065c98fc swift::TypeChecker::typeCheckTarget(swift::constraints::SolutionApplicationTarget&, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 784
58 swift-frontend           0x00000001065c95d0 swift::TypeChecker::typeCheckExpression(swift::constraints::SolutionApplicationTarget&, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 224
59 swift-frontend           0x00000001065c9410 swift::TypeChecker::typeCheckExpression(swift::Expr*&, swift::DeclContext*, swift::constraints::ContextualTypeInfo, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 188
60 swift-frontend           0x00000001066c2240 swift::expandMacroExpr(swift::DeclContext*, swift::Expr*, swift::ConcreteDeclRef, swift::Type) + 2712
61 swift-frontend           0x0000000106130e48 (anonymous namespace)::ExprRewriter::visitMacroExpansionExpr(swift::MacroExpansionExpr*) + 388
62 swift-frontend           0x0000000106128dc4 swift::ASTVisitor<(anonymous namespace)::ExprRewriter, swift::Expr*, void, void, void, void, void>::visit(swift::Expr*) + 2488
63 swift-frontend           0x000000010612839c (anonymous namespace)::ExprRewriter::walkToExprPost(swift::Expr*) + 36
64 swift-frontend           0x0000000106121608 (anonymous namespace)::ExprWalker::walkToExprPost(swift::Expr*) + 40
65 swift-frontend           0x0000000106f3f4f0 (anonymous namespace)::Traversal::doIt(swift::Expr*)::'lambda0'(swift::Expr*)::operator()(swift::Expr*) const + 48
66 swift-frontend           0x0000000106f3f4b4 swift::ASTWalker::PostWalkResult<swift::Expr*> llvm::function_ref<swift::ASTWalker::PostWalkResult<swift::Expr*> (swift::Expr*)>::callback_fn<(anonymous namespace)::Traversal::doIt(swift::Expr*)::'lambda0'(swift::Expr*)>(long, swift::Expr*) + 32
67 swift-frontend           0x0000000106f392c4 llvm::function_ref<swift::ASTWalker::PostWalkResult<swift::Expr*> (swift::Expr*)>::operator()(swift::Expr*) const + 40
68 swift-frontend           0x0000000106f3913c swift::Expr* (anonymous namespace)::Traversal::traverse<swift::Expr>(swift::ASTWalker::PreWalkResult<swift::Expr*>, llvm::function_ref<swift::Expr* (swift::Expr*)>, llvm::function_ref<swift::ASTWalker::PostWalkResult<swift::Expr*> (swift::Expr*)>) + 408
69 swift-frontend           0x0000000106f38598 (anonymous namespace)::Traversal::doIt(swift::Expr*) + 144
70 swift-frontend           0x0000000106f384c8 swift::Expr::walk(swift::ASTWalker&) + 56
71 swift-frontend           0x00000001061173f8 (anonymous namespace)::ExprWalker::rewriteTarget(swift::constraints::SolutionApplicationTarget) + 172
72 swift-frontend           0x00000001061170f4 swift::constraints::ConstraintSystem::applySolution(swift::constraints::Solution&, swift::constraints::SolutionApplicationTarget) + 680
73 swift-frontend           0x00000001065c9988 swift::TypeChecker::typeCheckTarget(swift::constraints::SolutionApplicationTarget&, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 924
74 swift-frontend           0x00000001065c95d0 swift::TypeChecker::typeCheckExpression(swift::constraints::SolutionApplicationTarget&, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 224
75 swift-frontend           0x00000001065cae44 swift::TypeChecker::typeCheckBinding(swift::Pattern*&, swift::Expr*&, swift::DeclContext*, swift::Type, swift::PatternBindingDecl*, unsigned int, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 384
76 swift-frontend           0x00000001065cb294 swift::TypeChecker::typeCheckPatternBinding(swift::PatternBindingDecl*, unsigned int, swift::Type, swift::OptionSet<swift::TypeCheckExprFlags, unsigned int>) + 404
77 swift-frontend           0x0000000106665a70 (anonymous namespace)::DeclChecker::visitPatternBindingDecl(swift::PatternBindingDecl*) + 904
78 swift-frontend           0x0000000106660208 swift::ASTVisitor<(anonymous namespace)::DeclChecker, void, void, void, void, void, void>::visit(swift::Decl*) + 1408
79 swift-frontend           0x00000001066566ac (anonymous namespace)::DeclChecker::visit(swift::Decl*) + 220
80 swift-frontend           0x0000000106656574 swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 92
81 swift-frontend           0x000000010689493c (anonymous namespace)::StmtChecker::typeCheckASTNode(swift::ASTNode&) + 836
82 swift-frontend           0x000000010689ae1c (anonymous namespace)::StmtChecker::visitBraceStmt(swift::BraceStmt*) + 464
83 swift-frontend           0x000000010689aa68 swift::ASTVisitor<(anonymous namespace)::StmtChecker, void, swift::Stmt*, void, void, void, void>::visit(swift::Stmt*) + 96
84 swift-frontend           0x0000000106896724 bool (anonymous namespace)::StmtChecker::typeCheckStmt<swift::BraceStmt>(swift::BraceStmt*&) + 156
85 swift-frontend           0x000000010689600c (anonymous namespace)::StmtChecker::typeCheckBody(swift::BraceStmt*&) + 36
86 swift-frontend           0x0000000106895af8 swift::TypeCheckFunctionBodyRequest::evaluate(swift::Evaluator&, swift::AbstractFunctionDecl*) const + 1592
87 swift-frontend           0x0000000106865838 swift::BraceStmt* swift::SimpleRequest<swift::TypeCheckFunctionBodyRequest, swift::BraceStmt* (swift::AbstractFunctionDecl*), (swift::RequestFlags)12>::callDerived<0ul>(swift::Evaluator&, std::__1::integer_sequence<unsigned long, 0ul>) const + 76
88 swift-frontend           0x0000000106860da8 swift::SimpleRequest<swift::TypeCheckFunctionBodyRequest, swift::BraceStmt* (swift::AbstractFunctionDecl*), (swift::RequestFlags)12>::evaluateRequest(swift::TypeCheckFunctionBodyRequest const&, swift::Evaluator&) + 32
89 swift-frontend           0x000000010731bca0 llvm::Expected<swift::TypeCheckFunctionBodyRequest::OutputType> swift::Evaluator::getResultUncached<swift::TypeCheckFunctionBodyRequest>(swift::TypeCheckFunctionBodyRequest const&) + 280
90 swift-frontend           0x000000010731bae8 llvm::Expected<swift::TypeCheckFunctionBodyRequest::OutputType> swift::Evaluator::getResultCached<swift::TypeCheckFunctionBodyRequest, (void*)0>(swift::TypeCheckFunctionBodyRequest const&) + 188
91 swift-frontend           0x000000010731b834 llvm::Expected<swift::TypeCheckFunctionBodyRequest::OutputType> swift::Evaluator::operator()<swift::TypeCheckFunctionBodyRequest, (void*)0>(swift::TypeCheckFunctionBodyRequest const&) + 68
92 swift-frontend           0x0000000107041d18 swift::TypeCheckFunctionBodyRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckFunctionBodyRequest>(swift::Evaluator&, swift::TypeCheckFunctionBodyRequest, swift::TypeCheckFunctionBodyRequest::OutputType) + 64
93 swift-frontend           0x0000000107041ccc swift::AbstractFunctionDecl::getTypecheckedBody() const + 84
94 swift-frontend           0x000000010691670c typeCheckDelayedFunctions(swift::SourceFile&) + 160
95 swift-frontend           0x00000001069164e8 swift::TypeCheckSourceFileRequest::evaluate(swift::Evaluator&, swift::SourceFile*) const + 568
96 swift-frontend           0x00000001068663e4 std::__1::tuple<> swift::SimpleRequest<swift::TypeCheckSourceFileRequest, std::__1::tuple<> (swift::SourceFile*), (swift::RequestFlags)12>::callDerived<0ul>(swift::Evaluator&, std::__1::integer_sequence<unsigned long, 0ul>) const + 76
97 swift-frontend           0x0000000106861200 swift::SimpleRequest<swift::TypeCheckSourceFileRequest, std::__1::tuple<> (swift::SourceFile*), (swift::RequestFlags)12>::evaluateRequest(swift::TypeCheckSourceFileRequest const&, swift::Evaluator&) + 32
98 swift-frontend           0x000000010691aa40 llvm::Expected<swift::TypeCheckSourceFileRequest::OutputType> swift::Evaluator::getResultUncached<swift::TypeCheckSourceFileRequest>(swift::TypeCheckSourceFileRequest const&) + 316
99 swift-frontend           0x000000010691a86c llvm::Expected<swift::TypeCheckSourceFileRequest::OutputType> swift::Evaluator::getResultCached<swift::TypeCheckSourceFileRequest, (void*)0>(swift::TypeCheckSourceFileRequest const&) + 184
100 swift-frontend           0x000000010691a714 llvm::Expected<swift::TypeCheckSourceFileRequest::OutputType> swift::Evaluator::operator()<swift::TypeCheckSourceFileRequest, (void*)0>(swift::TypeCheckSourceFileRequest const&) + 68
101 swift-frontend           0x00000001069161bc swift::TypeCheckSourceFileRequest::OutputType swift::evaluateOrDefault<swift::TypeCheckSourceFileRequest>(swift::Evaluator&, swift::TypeCheckSourceFileRequest, swift::TypeCheckSourceFileRequest::OutputType) + 60
102 swift-frontend           0x0000000106916174 swift::performTypeChecking(swift::SourceFile&) + 68
103 swift-frontend           0x0000000104765cd0 swift::CompilerInstance::performSema()::$_7::operator()(swift::SourceFile&) const + 28
104 swift-frontend           0x0000000104765ca4 bool llvm::function_ref<bool (swift::SourceFile&)>::callback_fn<swift::CompilerInstance::performSema()::$_7>(long, swift::SourceFile&) + 32
105 swift-frontend           0x0000000104749c2c llvm::function_ref<bool (swift::SourceFile&)>::operator()(swift::SourceFile&) const + 40
106 swift-frontend           0x000000010474995c swift::CompilerInstance::forEachFileToTypeCheck(llvm::function_ref<bool (swift::SourceFile&)>) + 184
107 swift-frontend           0x0000000104749888 swift::CompilerInstance::performSema() + 116
108 swift-frontend           0x00000001044dae1c withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 160
109 swift-frontend           0x00000001044d6018 performAction(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 960
110 swift-frontend           0x00000001044b4d14 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 220
111 swift-frontend           0x00000001044b3db8 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2088
112 swift-frontend           0x0000000104426990 run_driver(llvm::StringRef, llvm::ArrayRef<char const*>, llvm::ArrayRef<char const*>) + 748
113 swift-frontend           0x0000000104425c60 swift::mainEntry(int, char const**) + 1148
114 swift-frontend           0x00000001043fd310 main + 36
115 dyld                     0x0000000199457f34 start + 2248

It doesn't seem possible for a struct to inherit a protocol with primary associated type using this primary associated type in the declaration. In other words, the following doesn't compile:

protocol P<A> {
  associatedtype A
}
struct B {}

struct T: P<B> {} // Error: Cannot inherit from protocol type with generic argument 'P<B>'

This configuration was however explicitly mentioned in SE-0346, so I don't know if this is a bug, a regression, or feature that was not implemented at the end.

Environment

• Swift compiler version info: swift-driver version: 1.62.15 Apple Swift version 5.7.2 (swiftlang-5.7.2.135.5 clang-1400.0.29.51)
• Xcode version info: Version 14.2 (14C18)
• Deployment target: macOS 13.1

This changes opened pack element generic environments to store a shape equivalence class, and only include opened element parameters for originating packs in that shape class in the generic signature.