re: Passing strings from C++ to JavaScript in Web Assembly VIEW POST

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re: Good point about the dangers of -s ERROR_ON_UNDEFINED_SYMBOLS=0, thanks! I'll confess, I haven't explored using the --js-library flag yet. A quick...
 

The thing is:
if, in your C++ code, you define something as:

extern int GetFoo();

Then, if you build the code, you'll get an undefined symbol error, UNLESS this function can be "seen" by emscripten. It can only see it if you put it in a js file that it knows of. That is, a file that is passed to the --js-library flag.

What I usually do is something like:

C++: extern "C" void SomeFunction();

JS (in library.js) : SomeFunction : function() { _SomeFunction() }

And _SomeFunction is declared in the JavaScript project where I load the wasm module in.

You can find more details here:

emscripten.org/docs/porting/connec...

HTH

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