Bug 165977 – WebAssembly: test imports and exports with 16-bit characters

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

[JF Bastien]

The Builder should already handle these, but the parser uses consumeUTF8String which is suspicious.

[Saam Barati]

*** Bug 165976 has been marked as a duplicate of this bug. ***

[Saam Barati]

(In reply to comment #0)
> The Builder should already handle these, but the parser uses
> consumeUTF8String which is suspicious.

To elaborate, the implementation of consumeUTF8String looks wrong. Not the actual call to it. The implementation skips m_offset stringLength forward, which is wrong for 16 bit strings.

[Saam Barati]

(In reply to comment #2)
> (In reply to comment #0)
> > The Builder should already handle these, but the parser uses
> > consumeUTF8String which is suspicious.
> 
> To elaborate, the implementation of consumeUTF8String looks wrong. Not the
> actual call to it. The implementation skips m_offset stringLength forward,
> which is wrong for 16 bit strings.

Nevermind. We're treating a field of number of bytes from wasm as the *string length*. This is obviously wrong for 16 bit strings.

[Radar WebKit Bug Importer]

<rdar://problem/29760130>

[JF Bastien]

Created attachment 312256 [details]
patch

[Saam Barati]

Comment on attachment 312256 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=312256&action=review

r=me

> Source/JavaScriptCore/wasm/js/JSWebAssemblyInstance.cpp:141
> +        return before + String(" ") + String::fromUTF8(import.module) + ":" + String::fromUTF8(import.field) + " " + after;

you should use makeString here

[JF Bastien]

Created attachment 312275 [details]
patch

Use makeString.

[WebKit Commit Bot]

Comment on attachment 312275 [details]
patch

Clearing flags on attachment: 312275

Committed r217921: <http://trac.webkit.org/changeset/217921>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.