Open Radar

 
The following code reproducibly produces a segmentation fault on compilation:

class Foo {}

func sum<T: Foo, S: SequenceType where T == S.Generator.Element>(sequence: S) -> Foo {
    return Foo()
}

var theSum = sum([Foo(), Foo()])

The backtrace is:

0  swift                    0x00000001030b8968 llvm::sys::PrintStackTrace(__sFILE*) + 40
1  swift                    0x00000001030b8e54 SignalHandler(int) + 452
2  libsystem_platform.dylib 0x00007fff89d1df1a _sigtramp + 26
3  libsystem_platform.dylib 0x00007ff4d217bc50 _sigtramp + 1212538192
4  swift                    0x000000010244f258 swift::irgen::IRGenFunction::emitTypeMetadataRef(swift::CanType) + 280
5  swift                    0x00000001024831f3 swift::irgen::emitPolymorphicArguments(swift::irgen::IRGenFunction&, swift::CanTypeWrapper<swift::SILFunctionType>, swift::CanTypeWrapper<swift::SILFunctionType>, llvm::ArrayRef<swift::Substitution>, swift::irgen::Explosion&) + 451
6  swift                    0x00000001024c5f31 swift::SILVisitor<(anonymous namespace)::IRGenSILFunction, void>::visit(swift::ValueBase*) + 34721
7  swift                    0x00000001024bcb4b swift::irgen::IRGenModule::emitSILFunction(swift::SILFunction*) + 9195
8  swift                    0x0000000102436010 swift::irgen::IRGenModule::emitGlobalTopLevel() + 208
9  swift                    0x00000001024a986c performIRGeneration(swift::IRGenOptions&, swift::Module*, swift::SILModule*, llvm::StringRef, llvm::LLVMContext&, swift::SourceFile*, unsigned int) + 1900
10 swift                    0x00000001024aa273 swift::performIRGeneration(swift::IRGenOptions&, swift::SourceFile&, swift::SILModule*, llvm::StringRef, llvm::LLVMContext&, unsigned int) + 51
11 swift                    0x00000001023ff4f4 frontend_main(llvm::ArrayRef<char const*>, char const*, void*) + 5444
12 swift                    0x00000001023fc86d main + 1677
13 libdyld.dylib            0x00007fff8df1c5c9 start + 1