Flag that disables removal of forward declarations by reordering

[LeStahL]

Shader_Minifier by default reorders functions to be able to remove forward declarations.

While dealing with a single shader file containing all functions, or when combining shader sources before compilation, this technique is very useful to reduce shader source size in the executable.

In my use-case (32k intros) however, I compile shaders containing single functions, to avoid inlining and reduce compile time. The technique requires forward declarations to be present, but those will be optimized by Shader_Minifier.

I suggest

• either adding a command line switch to disable forward declaration removal by reordering
• or verifying that the forward declaration in question has a definition inside the minified sources before reordering and dropping it, keeping the forward declaration and not reordering if none is present.

to enable the use of Shader_Minifier when compiling functions separately.

I would be willing to submit a PR, should you decide you like the suggestion - just let me know if you like the idea (and which approach you prefer).

[laurentlb]

This sounds like a nice feature

If I remember correctly, the forward declaration is removed immediately (there's no AST node for it at all). So we need a change in the parser as well as the printer.

In your second proposal: we could drop the declaration if it isn't used at all. So "keep the forward declaration if it is referenced but not defined in the file".