[SR-6541] Swift Compiler Fills Memory Until Computer Crashes

[Frizlab]

Previous ID	SR-6541
Radar	rdar://problem/35882375
Original Reporter	@Frizlab
Type	Bug
Status	Resolved
Resolution	Duplicate

Environment

Xcode 9.2 (9C40b) on macOS Sierra (16G1036)

Additional Detail from JIRA

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

md5: 075ba9221f5127653f12eb99d046ec85

duplicates:

• SR-6540 swiftc Crash

Issue Description:

Try and compile the following Swift source:

print("Hello, World!")

struct Container {let string = "yes"}
let optionalContainer: Container? = Container()
let optionalString: String? = "toto"

switch optionalString {
case optionalContainer?.string?: ()
default: ()
}

The compiler just fills your memory until the computer crashes.

[Frizlab]

Most probably related to SR-6540

[slavapestov]

BindOptional expression is out of its depth
(bind_optional_expr type='Container' location=cr.swift:6:23 range=[cr.swift:6:6 - line:6:23] depth=0
(declref_expr type='Container?' location=cr.swift:6:6 range=[cr.swift:6:6 - line:6:6] decl=cr.(file).optionalContainer@cr.swift:3:5 direct_to_storage function_ref=unapplied))0  swift                    0x000000010c67cd28 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 40
1  swift                    0x000000010c67d3e6 SignalHandler(int) + 470
2  libsystem_platform.dylib 0x00007fff59989f5a _sigtramp + 26
3  swift                    0x000000010d2b6828 (anonymous namespace)::DarwinX86AsmBackend::getCompactUnwindRegNum(unsigned int) const::CU64BitRegs + 222898
4  libsystem_c.dylib        0x00007fff597b532a abort + 127
5  swift                    0x000000010a0af8f3 (anonymous namespace)::Verifier::walkToExprPost(swift::Expr*) + 14563
6  swift                    0x000000010a0be07e swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Expr*) + 1870
7  swift                    0x000000010a0be204 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Expr*) + 2260
8  swift                    0x000000010a0c1963 (anonymous namespace)::Traversal::visitApplyExpr(swift::ApplyExpr*) + 211
9  swift                    0x000000010a0c1a8b (anonymous namespace)::Traversal::visitSelfApplyExpr(swift::SelfApplyExpr*) + 91
10 swift                    0x000000010a0c18e6 (anonymous namespace)::Traversal::visitApplyExpr(swift::ApplyExpr*) + 86
11 swift                    0x000000010a0c3157 (anonymous namespace)::Traversal::visit(swift::Pattern*) + 1015
12 swift                    0x000000010a0c30e2 (anonymous namespace)::Traversal::visit(swift::Pattern*) + 898
13 swift                    0x000000010a0c2284 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Stmt*) + 1748
14 swift                    0x000000010a0c21a8 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Stmt*) + 1528
15 swift                    0x000000010a0c1c90 swift::ASTVisitor<(anonymous namespace)::Traversal, swift::Expr*, swift::Stmt*, bool, swift::Pattern*, bool, void>::visit(swift::Stmt*) + 224
16 swift                    0x000000010a0bd355 (anonymous namespace)::Traversal::doIt(swift::Decl*) + 1381
17 swift                    0x000000010a0bcddb swift::Decl::walk(swift::ASTWalker&) + 27
18 swift                    0x000000010a1580ea swift::SourceFile::walk(swift::ASTWalker&) + 170
19 swift                    0x000000010a0ab2eb swift::verify(swift::SourceFile&) + 59
20 swift                    0x0000000109e9204f swift::performTypeChecking(swift::SourceFile&, swift::TopLevelContext&, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>, unsigned int, unsigned int, unsigned int, unsigned int) + 1999
21 swift                    0x0000000109b1e533 swift::CompilerInstance::parseAndTypeCheckMainFile(swift::PersistentParserState&, swift::DelayedParsingCallbacks*, swift::OptionSet<swift::TypeCheckingFlags, unsigned int>) + 435
22 swift                    0x0000000109b1d3ec swift::CompilerInstance::parseAndCheckTypes(swift::CompilerInstance::ImplicitImports const&) + 764
23 swift                    0x0000000109b1cb74 swift::CompilerInstance::performSema() + 532
24 swift                    0x000000010900e1c5 performCompile(swift::CompilerInstance&, swift::CompilerInvocation&, llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*, swift::UnifiedStatsReporter*) + 1781
25 swift                    0x000000010900cb0a swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3210
26 swift                    0x0000000108fcd9b0 main + 3360
27 libdyld.dylib            0x00007fff59709145 start + 1

[belkadan]

Anything that crashes will almost certainly crash the same way when unrelated code is added before it. No need to file a second bug for that.

[Frizlab]

@belkadan Yes of course. The behaviour I got was very different though (one segfaulted; the other did not crash but was leaking many GB of memory per seconds), so I thought it might have been interesting to get both.

[belkadan]

Yeah, that makes sense. I think we can still track them together in this case.