[SR-4866] Stack overflow: Parsing phony empty paren exprs

[bitjammer]

Previous ID	SR-4866
Radar	None
Original Reporter	@bitjammer
Type	Bug
Status	Resolved
Resolution	Done

Attachment: Download

Additional Detail from JIRA

Votes	0
Component/s	Compiler
Labels	Bug, CompilerCrash, Parser, StarterBug
Assignee	christopherstern (JIRA)
Priority	Medium

md5: 5b7a64ad744a870b56645db75101ffef

Issue Description:

Parse the attached file. Stack overflow.

495 swift 0x0000000106d9e9aa swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&) + 218
496 swift 0x0000000106d9efb1 swift::Parser::parseExprList(swift::tok, swift::tok) + 209
497 swift 0x0000000106d949e0 swift::Parser::parseExprPostfix(swift::Diag<>, bool) + 2416
498 swift 0x0000000106d926b5 swift::Parser::parseExprSequence(swift::Diag<>, bool, bool) + 3717
499 swift 0x0000000106d91795 swift::Parser::parseExprImpl(swift::Diag<>, bool) + 101
500 swift 0x0000000106da0be1 std::**1::function::func<swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&)::$2, std::_1::allocator<swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&)::$_2>, swift::ParserStatus ()>::operator()() + 113
501 swift 0x0000000106dafa6c swift::Parser::parseList(swift::tok, swift::SourceLoc, swift::SourceLoc&, bool, swift::Diag<>, std::_1::function<swift::ParserStatus ()>) + 396
502 swift 0x0000000106d9e9aa swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&) + 218
503 swift 0x0000000106d9efb1 swift::Parser::parseExprList(swift::tok, swift::tok) + 209
504 swift 0x0000000106d949e0 swift::Parser::parseExprPostfix(swift::Diag<>, bool) + 2416
505 swift 0x0000000106d926b5 swift::Parser::parseExprSequence(swift::Diag<>, bool, bool) + 3717
506 swift 0x0000000106d91795 swift::Parser::parseExprImpl(swift::Diag<>, bool) + 101
507 swift 0x0000000106da0be1 std::1::function::func<swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&)::$2, std::_1::allocator<swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&)::$_2>, swift::ParserStatus ()>::operator()() + 113
508 swift 0x0000000106dafa6c swift::Parser::parseList(swift::tok, swift::SourceLoc, swift::SourceLoc&, bool, swift::Diag<>, std::_1::function<swift::ParserStatus ()>) + 396
509 swift 0x0000000106d9e9aa swift::Parser::parseExprList(swift::tok, swift::tok, bool, bool, swift::SourceLoc&, llvm::SmallVectorImpl<swift::Expr*>&, llvm::SmallVectorImpl<swift::Identifier>&, llvm::SmallVectorImpl<swift::SourceLoc>&, swift::SourceLoc&, swift::Expr*&) + 218
510 swift 0x0000000106d9efb1 swift::Parser::parseExprList(swift::tok, swift::tok) + 209
511 swift 0x0000000106d949e0 swift::Parser::parseExprPostfix(swift::Diag<>, bool) + 2416

etc.

[swift-ci]

Comment by Christopher Ian Stern (JIRA)

Apple Swift version 4.2 (swiftlang-1000.11.37.1 clang-1000.11.45.1) crashes on the provided file `t.swift` without a much of a diagnostic

{{ $ swiftc t.swift}}

{{ <unknown>:0: error: unable to execute command: Illegal instruction: 4}}
{{ <unknown>:0: error: compile command failed due to signal 4 (use -v to see invocation)}}

The file is rather silly though swift is being rather unhelpful here.

The same stack overflow happens in a simpler case, with just a large number of parens that is

let x = ((((((((...

if you use enough parens.

manyparen.swift

[swift-ci]

Comment by Christopher Ian Stern (JIRA)

This was fixed by PR-19631, merged into master on Oct 9.

The file t.swift is now in the tests as file swift/test/Parse/structure_overflow_paren_exprs.swift

Resolving