Open Radar

 
Summary:
N/A


Steps to Reproduce:
This code:
extension SequenceType {
	func f<A>(a: A) -> Generator {
		func g<A>(a: A) -> Generator {}
	}
}


Expected Results:
shouldn’t crash swiftc


Actual Results:
but totally does:
rob@Resonance ~/Desktop> swiftc boom.swift; and ./boom
0  swift                    0x00000001066ccedb llvm::sys::PrintStackTrace(__sFILE*) + 43
1  swift                    0x00000001066cd61b SignalHandler(int) + 379
2  libsystem_platform.dylib 0x00007fff85b2c52a _sigtramp + 26
3  libsystem_c.dylib        0x00007fff850107fa vsprintf_l + 399
4  swift                    0x000000010495dc80 swift::Lowering::TypeConverter::getFunctionTypeWithCaptures(swift::CanTypeWrapper<swift::AnyFunctionType>, swift::AnyFunctionRef) + 272
5  swift                    0x000000010495e916 swift::Lowering::TypeConverter::makeConstantType(swift::SILDeclRef, bool) + 854
6  swift                    0x0000000104917e9a swift::Lowering::TypeConverter::getConstantInfo(swift::SILDeclRef) + 250
7  swift                    0x000000010493a943 swift::SILModule::getOrCreateFunction(swift::SILLocation, swift::SILDeclRef, swift::ForDefinition_t) + 147
8  swift                    0x000000010497aaf5 swift::Lowering::SILGenModule::getFunction(swift::SILDeclRef, swift::ForDefinition_t) + 117
9  swift                    0x000000010497afb7 swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 375
10 swift                    0x00000001049f1ec9 swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void, void, void, void>::visit(swift::Stmt*) + 425
11 swift                    0x00000001049f1d15 swift::Lowering::SILGenFunction::emitStmt(swift::Stmt*) + 21
12 swift                    0x00000001049c2e7b swift::Lowering::SILGenFunction::emitFunction(swift::FuncDecl*) + 331
13 swift                    0x000000010497b01f swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 479
14 swift                    0x00000001049f752c swift::ASTVisitor<SILGenExtension, void, void, void, void, void, void>::visit(swift::Decl*) + 300
15 swift                    0x00000001049f718b SILGenExtension::emitExtension(swift::ExtensionDecl*) + 59
16 swift                    0x00000001049f6b35 swift::Lowering::SILGenModule::visitExtensionDecl(swift::ExtensionDecl*) + 21
17 swift                    0x000000010497e76b swift::Lowering::SILGenModule::emitSourceFile(swift::SourceFile*, unsigned int) + 779
18 swift                    0x000000010497f330 swift::SILModule::constructSIL(swift::ModuleDecl*, swift::SILOptions&, swift::FileUnit*, llvm::Optional<unsigned int>, bool, bool) + 944
19 swift                    0x000000010497f6dd swift::performSILGeneration(swift::FileUnit&, swift::SILOptions&, llvm::Optional<unsigned int>, bool) + 109
20 swift                    0x00000001047ddfd5 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&) + 11445
21 swift                    0x00000001047db10a frontend_main(llvm::ArrayRef<char const*>, char const*, void*) + 2682
22 swift                    0x00000001047d7797 main + 2247
23 libdyld.dylib            0x00007fff9494a5ad start + 1
24 libdyld.dylib            0x000000000000000f start + 1802197603
Stack dump:
0.	Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -c -primary-file boom.swift -target x86_64-apple-darwin15.0.0 -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -color-diagnostics -module-name boom -o /var/folders/9y/f7n4rvx901nctm_5d16c1wm40000gn/T/boom-efc993.o 
1.	While emitting SIL for 'f' at boom.swift:2:2
2.	While emitting SIL for 'g' at boom.swift:3:3
<unknown>:0: error: unable to execute command: Segmentation fault: 11
<unknown>:0: error: swift frontend command failed due to signal (use -v to see invocation)


Regression:
Both functions have to be generic to crash.
Both functions have to reference an associated type to crash.
It has to be in a protocol extension to crash.

Notes:
N/A