emscripten-core/emscripten

WebIDL + JSImplementation + DOMString

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#10,705 opened on Mar 17, 2020

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good first bughelp wanted

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Description

The following IDL does not generate correct bindings:

interface CTest
{
  void CTest();
  void OnStartElement([Const] DOMString pszName, [Const] DOMString[] papszAttrs);
};

[JSImplementation = "CTest"]
interface CTestJS {
  void CTestJS();
  void OnStartElement([Const] DOMString pszName, [Const] DOMString[] papszAttrs);
};

Specifically both pszName + papszAttrs end up in the JS code as pointers.

Contributor guide

Research direction
Investigate how emscripten's IDL binding generator handles [Const] DOMString and DOMString[] parameters. Trace the code path from the IDL parser to the generated JS bindings to understand why they become pointers instead of strings.
Tech stack
cppjavascript
Domain
compilerstooling
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
WebIDL
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30