Bug 168844 – ASSERTION FAILED: "We should only declare a function as a lexically scoped variable in scopes where var declarations aren't allowed. ..." for function redeclaration with async function module export

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[André Bargull]

svn revision: 212968

Test case:
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checkModuleSyntax("function f(){} export async function f() {}");
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Fails with:
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ASSERTION FAILED: We should only declare a function as a lexically scoped variable in scopes where var declarations aren't allowed. I.e, in strict mode and not at the top-level scope of a function or program.
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Stacktrace:
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#0  0x00007ffff6d97a4e in WTFCrash () at ../../Source/WTF/wtf/Assertions.cpp:323
#1  0x00007ffff698fad8 in JSC::Scope::declareFunction (this=0x7fffffffa100, ident=0x7fffef5d9200, declareAsVar=false, isSloppyModeHoistingCandidate=false)
    at ../../Source/JavaScriptCore/parser/Parser.h:397
#2  0x00007ffff699d3e1 in JSC::Parser<JSC::Lexer<unsigned char> >::declareFunction (this=0x7fffffffa0f0, ident=0x7fffef5d9200) at ../../Source/JavaScriptCore/parser/Parser.h:1228
#3  0x00007ffff69cf8ef in JSC::Parser<JSC::Lexer<unsigned char> >::parseAsyncFunctionDeclaration<JSC::ASTBuilder> (this=0x7fffffffa0f0, context=..., 
    exportType=JSC::Parser<JSC::Lexer<unsigned char> >::ExportType::Exported, declarationDefaultContext=JSC::DeclarationDefaultContext::Standard) at ../../Source/JavaScriptCore/parser/Parser.cpp:2474
#4  0x00007ffff69bc262 in JSC::Parser<JSC::Lexer<unsigned char> >::parseExportDeclaration<JSC::ASTBuilder> (this=0x7fffffffa0f0, context=...) at ../../Source/JavaScriptCore/parser/Parser.cpp:3301
#5  0x00007ffff69ad691 in JSC::Parser<JSC::Lexer<unsigned char> >::parseModuleSourceElements<JSC::ASTBuilder> (this=0x7fffffffa0f0, context=..., parseMode=JSC::SourceParseMode::ModuleAnalyzeMode)
    at ../../Source/JavaScriptCore/parser/Parser.cpp:380
#6  0x00007ffff699dbf1 in JSC::Parser<JSC::Lexer<unsigned char> >::parseInner (this=0x7fffffffa0f0, calleeName=..., parseMode=JSC::SourceParseMode::ModuleAnalyzeMode)
    at ../../Source/JavaScriptCore/parser/Parser.cpp:207
#7  0x00007ffff62f27a1 in JSC::Parser<JSC::Lexer<unsigned char> >::parse<JSC::ModuleProgramNode> (this=0x7fffffffa0f0, error=..., calleeName=..., parseMode=JSC::SourceParseMode::ModuleAnalyzeMode)
    at ../../Source/JavaScriptCore/parser/Parser.h:1811
#8  0x00007ffff62f2167 in JSC::parse<JSC::ModuleProgramNode> (vm=0x7fffaf000000, source=..., name=..., builtinMode=JSC::JSParserBuiltinMode::NotBuiltin, strictMode=JSC::JSParserStrictMode::Strict, 
    scriptMode=JSC::JSParserScriptMode::Module, parseMode=JSC::SourceParseMode::ModuleAnalyzeMode, superBinding=JSC::SuperBinding::NotNeeded, error=..., positionBeforeLastNewline=0x0, 
    defaultConstructorKind=JSC::ConstructorKind::None, derivedContextType=JSC::DerivedContextType::None, evalContextType=JSC::EvalContextType::None, debuggerParseData=0x0)
    at ../../Source/JavaScriptCore/parser/Parser.h:1900
#9  0x00007ffff6aea605 in JSC::checkModuleSyntax (exec=0x7fffffffc740, source=..., error=...) at ../../Source/JavaScriptCore/runtime/Completion.cpp:79
#10 0x0000000000466689 in functionCheckModuleSyntax (exec=0x7fffffffc740) at ../../Source/JavaScriptCore/jsc.cpp:2939
...
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[Radar WebKit Bug Importer]

<rdar://problem/30724820>

[Yusuke Suzuki]

Working on it right now.

[Yusuke Suzuki]

Created attachment 311811 [details]
Patch

[Saam Barati]

Comment on attachment 311811 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=311811&action=review

> JSTests/modules/async-function-export.js:1
> +function f()

What are the semantics for this? If I tried to call “f” below, which one would I call?

[Yusuke Suzuki]

Comment on attachment 311811 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=311811&action=review

Thanks.

>> JSTests/modules/async-function-export.js:1
>> +function f()
> 
> What are the semantics for this? If I tried to call “f” below, which one would I call?

Latter one. Same as

function f() { }
function f() { } case.

[Yusuke Suzuki]

Committed r217755: <http://trac.webkit.org/changeset/217755>