Swift 1.2b2: Compiler crash in ArchetypeBuilder with recursive type constraints through protocol

Originator:rix.rob
Number:rdar://20000145 Date Originated:01-Mar-2015 01:50 PM
Status:Open Resolved:
Product:Developer Tools Product Version:Xcode-beta (6D532l)
Classification:Crash/Hang/Data Loss Reproducible:Always
 
Summary:
Trying to make a fixpoint type while working around Swift’s lack of second order types.


Steps to Reproduce:
1. Compile this
public protocol P { typealias T }
public struct S<A: P where A.T == S<A>> {}


Expected Results:
I expected it to compile.


Actual Results:
Compiler crashes


Regression:
I haven’t found any workarounds yet. Haven’t tested older versions. Too tired. Send… send chocolate…!


Notes:
4  swift                    0x0000000105013959 swift::ArchetypeBuilder::resolveArchetype(swift::Type) + 25
5  swift                    0x0000000105015435 swift::ArchetypeBuilder::addSameTypeRequirement(swift::Type, swift::Type, swift::RequirementSource) + 37
6  swift                    0x0000000105015511 swift::ArchetypeBuilder::addRequirement(swift::RequirementRepr const&) + 65
7  swift                    0x0000000104f9ce69 checkGenericParameters(swift::TypeChecker&, swift::ArchetypeBuilder*, swift::GenericParamList*, swift::DeclContext*, swift::GenericTypeResolver&) + 889
8  swift                    0x0000000104f9c7d2 swift::TypeChecker::validateGenericSignature(swift::GenericParamList*, swift::DeclContext*, swift::GenericSignature*, std::__1::function<bool (swift::ArchetypeBuilder&)>, bool&) + 130
9  swift                    0x0000000104f9cf3e swift::TypeChecker::validateGenericTypeSignature(swift::NominalTypeDecl*) + 78
10 swift                    0x0000000104f7ed05 swift::TypeChecker::validateDecl(swift::ValueDecl*, bool) + 245
11 swift                    0x0000000104f890b0 swift::ASTVisitor<(anonymous namespace)::DeclChecker, void, void, void, void, void, void>::visit(swift::Decl*) + 640
12 swift                    0x0000000104f8222c swift::TypeChecker::typeCheckDecl(swift::Decl*, bool) + 124
13 swift                    0x0000000104f64a38 swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int) + 1128
14 swift                    0x000000010461ce2c swift::CompilerInstance::performSema() + 2428
15 swift                    0x00000001042faaf4 frontend_main(llvm::ArrayRef<char const*>, char const*, void*) + 2148
16 swift                    0x00000001042fa0e6 main + 1814

Comments

No longer crashes (after changing typealias to associatedtype) with DEVELOPMENT-SNAPSHOT-2016-05-03-a (LLVM dffa09ffd8, Clang 1e6cba3ce3, Swift d2aee43220).

By jdhealy at June 9, 2016, 4:17 p.m. (reply...)

No longer crashes (after changing typealias to associatedtype) with DEVELOPMENT-SNAPSHOT-2016-05-03-a (LLVM dffa09ffd8, Clang 1e6cba3ce3, Swift d2aee43220).

By jdhealy at June 9, 2016, 4:17 p.m. (reply...)

also crashes with Swift 1.1, jfyi

By dieter.komendera at March 1, 2015, 7:13 p.m. (reply...)

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