Accessing errno and constants, such as ENOEXEC in JS

[iliakan]

Is there a way to set C errno from JS? Should I create a special C-function for that void set_errno(int my_errno), or there's a more elegant way?

I see a built-in __errno_location function, should I use it? Or maybe stay away from it, cause it's internal?

Also, there're constants, such as ENOEXEC and others, should I export ERRNO_CODES to access them in JavaScript (for the purpose of returning to C)?

[sbc100]

If the code you are writing is in a library JS file you can use the preprocessor to get access to them like this: var code = {{{ cDefine('EINVAL') }}}.

Otherwise you can use the ERRNO_CODES library helper:

emscripten/src/library.js

Line 1282 in 168dafb

$ERRNO_CODES__postset: `ERRNO_CODES = {

You can force that to be include with -sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=$ERRNO_CODES, and exported using -sEXPORTED_FUNCTIONS=ERRNO_CODES (node the $ in the first list and the lack of $ in the second). If you want of those then I think you can also do -sEXPORTED_RUNTIME_METHODS=ERRNO_CODES...

[iliakan]

Thankd.

Solved by -sEXPORTED_RUNTIME_METHODS=setErrNo,ERRNO_CODES =)