[SR-11483] "Module Verifier" crash with library evolution

[keith]

Previous ID	SR-11483
Radar	rdar://problem/55442325
Original Reporter	@keith
Type	Bug

Environment

Xcode 11.0 (11A420a)

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, CompilerCrash, LibraryEvolution
Assignee	None
Priority	Medium

md5: 3630241aff317b63db0456e6e77ede35

Issue Description:

With this code:

import UIKit

public protocol Foo: UITableViewHeaderFooterView {
    init()
}

If you compile it with:

xcrun -sdk iphonesimulator swiftc -target x86_64-apple-ios11.0-simulator -parse-as-library -enable-library-evolution -emit-module-interface-path foo.swiftinterface -module-name foo -emit-object "foo.swift"

You get this crash:

loading unsized types is not allowed
  load void, void* %19, align 8
Function return type does not match operand type of return inst!
  ret void <badref>
 %TSo023UITableViewHeaderFooterB0C*in function $s3foo3FooPxycfC
<unknown>:0: error: fatal error encountered during compilation; please file a bug report with your project and the crash log
<unknown>:0: note: Broken function found, compilation aborted!
Stack dump:
0.      Program arguments: /Applications/Xcode-11.0.0-GM2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -c -primary-file foo.swift -emit-module-path /var/folders/q5/7_wh20z93c74nj3tllwjl5nr0000gn/T/foo-5b9f4b.swiftmodule -emit-module-doc-path /var/folders/q5/7_wh20z93c74nj3tllwjl5nr0000gn/T/foo-5b9f4b.swiftdoc -target x86_64-apple-ios11.0-simulator -enable-objc-interop -sdk /Applications/Xcode-11.0.0-GM2.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator13.0.sdk -enable-library-evolution -color-diagnostics -parse-as-library -module-name foo -o /var/folders/q5/7_wh20z93c74nj3tllwjl5nr0000gn/T/foo-5b9f4b.o
1.      Running pass 'Module Verifier' on function '@"$s3foo3FooPxycfC"'
0  swift                    0x000000010d3fdeb3 PrintStackTraceSignalHandler(void*) + 51
1  swift                    0x000000010d3fd686 SignalHandler(int) + 358
2  libsystem_platform.dylib 0x00007fff7cc51b5d _sigtramp + 29
3  libsystem_platform.dylib 0x00007ffee6c46280 _sigtramp + 1778337600
4  libsystem_c.dylib        0x00007fff7cb0b6a6 abort + 127
5  swift                    0x000000010904c330 std::__1::unique_ptr<swift::DiagnosticConsumer, std::__1::default_delete<swift::DiagnosticConsumer> > llvm::function_ref<std::__1::unique_ptr<swift::DiagnosticConsumer, std::__1::default_delete<swift::DiagnosticConsumer> > (swift::InputFile const&)>::callback_fn<createSerializedDiagnosticConsumerIfNeeded(swift::FrontendInputsAndOutputs const&)::$_15>(long, swift::InputFile const&) + 0
6  swift                    0x000000010d376cd6 llvm::report_fatal_error(llvm::Twine const&, bool) + 278
7  swift                    0x000000010d376bbb llvm::report_fatal_error(char const*, bool) + 43
8  swift                    0x000000010d336f23 (anonymous namespace)::VerifierLegacyPass::runOnFunction(llvm::Function&) + 115
9  swift                    0x000000010d2d9196 llvm::FPPassManager::runOnFunction(llvm::Function&) + 1590
10 swift                    0x000000010d2e410e llvm::legacy::FunctionPassManager::run(llvm::Function&) + 446
11 swift                    0x00000001092640d8 swift::performLLVM(swift::IRGenOptions&, swift::DiagnosticEngine*, llvm::sys::SmartMutex<false>*, llvm::GlobalVariable*, llvm::Module*, llvm::TargetMachine*, swift::version::Version const&, llvm::StringRef, swift::UnifiedStatsReporter*) + 4648
12 swift                    0x0000000109055de3 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 38307
13 swift                    0x0000000109049034 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 6820
14 swift                    0x0000000108fd65a3 main + 1219
15 libdyld.dylib            0x00007fff7ca663d5 start + 1
<unknown>:0: error: unable to execute command: Abort trap: 6
<unknown>:0: error: compile command failed due to signal 6 (use -v to see invocation)

[keith]

We've hit a few more cases of this, it looks like any place we have an initializer in a protocol that inherits from an objc type

[belkadan]

@swift-ci create

[keith]

FWIW this still repros with Swift master, it hits this assertion https://github.com/apple/swift/blob/103961a7d5f8853ac518f4d8151de0f5b64d8ccf/lib/SILGen/SILGenPoly.cpp#L626-L627

[swift-ci]

Comment by Cody Vandermyn (JIRA)

I'm seeing a similar issue with the following code:

import Foundation
public protocol FooType: Foo {
    init()
    func doStuff()
}

open class Foo {
    public required init() {}
    public required init(string: String?) {}
    public func doStuff() {
        print("doStuff")
    }
}

The compiler crash is:

Unhandled transform?
UNREACHABLE executed at ~/Github/swift-project/swift/lib/SILGen/SILGenPoly.cpp:627!
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.

Stack dump:
0.  Program arguments: ~/Desktop/Github/swift-project/build/Xcode-RelWithDebInfoAssert+swift-DebugAssert/swift-macosx-x86_64/Debug/bin/swift-frontend -frontend -emit-silgen -primary-file hello.swift -target x86_64-apple-ios11.0-simulator -enable-objc-interop -sdk /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.0.sdk -color-diagnostics -I /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/lib -F /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Library/Frameworks -enable-library-evolution -O -target-sdk-version 14.0 -module-name hello -o - 
1.  Swift version 5.3-dev (LLVM 40349c774225a09, Swift 8920da22a64a750)
2.  While evaluating request ASTLoweringRequest(Lowering AST to SIL for file "hello.swift")
3.  While generating protocol witness thunk SIL function "@$s5hello7FooTypePxycfC".
 for 'init()' (at hello.swift:17:21)
0  swift-frontend           0x000000011223a495 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37
1  swift-frontend           0x0000000112239665 llvm::sys::RunSignalHandlers() + 85
2  swift-frontend           0x000000011223aa86 SignalHandler(int) + 262
3  libsystem_platform.dylib 0x00007fff6a9e15fd _sigtramp + 29
4  libsystem_platform.dylib 0x0000000134b45b8d _sigtramp + 18446603343906620845
5  libsystem_c.dylib        0x00007fff6a8b7808 abort + 120
6  swift-frontend           0x00000001121eadb2 llvm::llvm_unreachable_internal(char const*, char const*, unsigned int) + 482
7  swift-frontend           0x000000010c3e4823 (anonymous namespace)::Transform::transform(swift::Lowering::ManagedValue, swift::Lowering::AbstractionPattern, swift::CanType, swift::Lowering::AbstractionPattern, swift::CanType, swift::SILType, swift::Lowering::SGFContext) + 8835
8  swift-frontend           0x000000010c3e12f4 swift::Lowering::SILGenFunction::emitTransformedValue(swift::SILLocation, swift::Lowering::ManagedValue, swift::Lowering::AbstractionPattern, swift::CanType, swift::Lowering::AbstractionPattern, swift::CanType, swift::SILType, swift::Lowering::SGFContext) + 468
9  swift-frontend           0x000000010c413910 (anonymous namespace)::ResultPlanner::execute(llvm::ArrayRef<swift::SILValue>, llvm::SmallVectorImpl<swift::SILValue>&)::$_22::operator()((anonymous namespace)::ResultPlanner::Operation&, bool, bool) const + 928
10 swift-frontend           0x000000010c412aa9 (anonymous namespace)::ResultPlanner::execute(llvm::ArrayRef<swift::SILValue>, llvm::SmallVectorImpl<swift::SILValue>&) + 1209
11 swift-frontend           0x000000010c3e764e (anonymous namespace)::ResultPlanner::execute(swift::SILValue) + 478
12 swift-frontend           0x000000010c3e9087 swift::Lowering::SILGenFunction::emitProtocolWitness(swift::Lowering::AbstractionPattern, swift::CanTypeWrapper<swift::AnyFunctionType>, swift::SILDeclRef, swift::SubstitutionMap, swift::SILDeclRef, swift::SubstitutionMap, swift::Lowering::IsFreeFunctionWitness_t, bool) + 3927
13 swift-frontend           0x000000010c439089 swift::Lowering::SILGenModule::emitProtocolWitness(swift::ProtocolConformanceRef, swift::SILLinkage, swift::IsSerialized_t, swift::SILDeclRef, swift::SILDeclRef, swift::Lowering::IsFreeFunctionWitness_t, swift::Witness) + 3033
14 swift-frontend           0x000000010c44cb05 (anonymous namespace)::SILGenDefaultWitnessTable::addMethodImplementation(swift::SILDeclRef, swift::SILDeclRef, swift::Lowering::IsFreeFunctionWitness_t, swift::Witness) + 277
15 swift-frontend           0x000000010c44c9bb (anonymous namespace)::SILGenWitnessTable<(anonymous namespace)::SILGenDefaultWitnessTable>::addMethodImplementation(swift::SILDeclRef, swift::SILDeclRef, swift::Witness) + 235
16 swift-frontend           0x000000010c44c1c3 (anonymous namespace)::SILGenWitnessTable<(anonymous namespace)::SILGenDefaultWitnessTable>::addMethod(swift::SILDeclRef) + 691
17 swift-frontend           0x000000010c44b808 swift::SILWitnessVisitor<(anonymous namespace)::SILGenDefaultWitnessTable>::visitConstructorDecl(swift::ConstructorDecl*) + 168
18 swift-frontend           0x000000010c44b104 swift::ASTVisitor<(anonymous namespace)::SILGenDefaultWitnessTable, void, void, void, void, void, void>::visit(swift::Decl*) + 980
19 swift-frontend           0x000000010c439dbd swift::SILWitnessVisitor<(anonymous namespace)::SILGenDefaultWitnessTable>::visitProtocolDecl(swift::ProtocolDecl*) + 1309
20 swift-frontend           0x000000010c4397de swift::Lowering::SILGenModule::emitDefaultWitnessTable(swift::ProtocolDecl*) + 158
21 swift-frontend           0x000000010c43a110 (anonymous namespace)::SILGenType::emitType() + 640
22 swift-frontend           0x000000010c439e5a swift::Lowering::SILGenModule::visitNominalTypeDecl(swift::NominalTypeDecl*) + 42
23 swift-frontend           0x000000010c22ed53 swift::ASTVisitor<swift::Lowering::SILGenModule, void, void, void, void, void, void>::visitProtocolDecl(swift::ProtocolDecl*) + 35
24 swift-frontend           0x000000010c22d770 swift::ASTVisitor<swift::Lowering::SILGenModule, void, void, void, void, void, void>::visit(swift::Decl*) + 384
25 swift-frontend           0x000000010c221d44 (anonymous namespace)::SILGenModuleRAII::emitSourceFile(swift::SourceFile*) + 244
26 swift-frontend           0x000000010c221966 swift::ASTLoweringRequest::evaluate(swift::Evaluator&, swift::ASTLoweringDescriptor) const + 710
27 swift-frontend           0x000000010c41da77 std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> > swift::SimpleRequest<swift::ASTLoweringRequest, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> > (swift::ASTLoweringDescriptor), (swift::RequestFlags)9>::callDerived<0ul>(swift::Evaluator&, std::__1::integer_sequence<unsigned long, 0ul>) const + 119
28 swift-frontend           0x000000010c41d9ae swift::SimpleRequest<swift::ASTLoweringRequest, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule> > (swift::ASTLoweringDescriptor), (swift::RequestFlags)9>::evaluateRequest(swift::ASTLoweringRequest const&, swift::Evaluator&) + 46
29 swift-frontend           0x000000010c24775d llvm::Expected<swift::ASTLoweringRequest::OutputType> swift::Evaluator::getResultUncached<swift::ASTLoweringRequest>(swift::ASTLoweringRequest const&) + 413
30 swift-frontend           0x000000010c2222c0 llvm::Expected<swift::ASTLoweringRequest::OutputType> swift::Evaluator::operator()<swift::ASTLoweringRequest, (void*)0>(swift::ASTLoweringRequest const&) + 96
31 swift-frontend           0x000000010c22241d swift::performASTLowering(swift::FileUnit&, swift::Lowering::TypeConverter&, swift::SILOptions const&) + 237
32 swift-frontend           0x000000010b8f19bc performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 524
33 swift-frontend           0x000000010b8f17a0 performAction(swift::CompilerInstance&, int&, swift::FrontendObserver*)::$_22::operator()(swift::CompilerInstance&) const + 144
34 swift-frontend           0x000000010b8f1700 bool llvm::function_ref<bool (swift::CompilerInstance&)>::callback_fn<performAction(swift::CompilerInstance&, int&, swift::FrontendObserver*)::$_22>(long, swift::CompilerInstance&) + 48
35 swift-frontend           0x000000010b8e6d2c llvm::function_ref<bool (swift::CompilerInstance&)>::operator()(swift::CompilerInstance&) const + 60
36 swift-frontend           0x000000010b8e5c71 withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>) + 337
37 swift-frontend           0x000000010b8e3794 performAction(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1044
38 swift-frontend           0x000000010b8d9b42 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 290
39 swift-frontend           0x000000010b8d8d93 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2003
40 swift-frontend           0x000000010b79cb57 run_driver(llvm::StringRef, llvm::ArrayRef<char const*>) + 263
41 swift-frontend           0x000000010b79bfe9 main + 2009
42 libdyld.dylib            0x00007fff6a7e8cc9 start + 1
[1]    49933 abort      ./Debug/bin/swiftc -emit-silgen -target x86_64-apple-ios11.0-simulator -sdk 

And there at least a few options that remove the crash:

Option 1:

import Foundation

@objc
public protocol FooType where Self: Foo {
    init()
    init(string: String?)
    func doStuff()
}

open class Foo {
    public required init() {}
    public required init(string: String?) {}
    public func doStuff() {
        print("doStuff")
    }
}

Option 2:

import Foundation

public protocol FooType {
    init()
    init(string: String?)
    func doStuff()
}

open class Foo: FooType {
    public required init() {}
    public required init(string: String?) {}
    public func doStuff() {
        print("doStuff")
    }
}

Option 3:

import Foundation

public protocol FooType: Foo {
    func doStuff()
}

open class Foo {
    public required init() {}
    public required init(string: String?) {}
    public func doStuff() {
        print("doStuff")
    }
}

Note that it doesn't matter the `init` signature and I'm using 2 `init`s here just for examples, one or the other also causes the crash.