Generalize reuse

[eldritchconundrum]

No description provided.

[therontarigo]

This is great for fully minified shaders, but confusing when --no-renaming is used:

int test()
{
  int one=1, two=2, three=one+two;
  return three;
}

becomes (with --no-renaming --no-inlining)

int test()
{
  int one=1,two=2;
  one+=two;
  return one;
}

should identifiers from the no-renaming-list be excluded from reuse?

[eldritchconundrum]

I think it would be best for renaming to stay independent from rewrites, so that --no-renaming can be used as a debugging step to understand how a minified shader is failing.
Maybe we could make a separate flag to disable variable reuse... Or use --no-renaming-list, I forgot that it also applies to variables.

[therontarigo]

That's a separate issue of --no-renaming-list applying to everything when the help suggests it applies to function names only.

--no-renaming can be used as a debugging step

This is specifically where it's problematic: in large functions, reuse has the same obfuscating effect that renaming does for making debugging more difficult: looking through the tests for examples, "dlt" became "height", "specular" became "lightDir", "dir" became "camTarget", and so forth.

Splitting --no-renaming option into separate options for global renaming vs. local renaming could help solve this, with no-local-renaming implying no local reuse.