How do I find the location of an installed binary from a package?

[lasagnaphil]

I am currently writing an application that needs some code generation before C++ compliation. More specifically, I'm using a tool called sokol-shdc which converts GLSL shaders to header files. sokol-shdc is provided by a custom package called sokol-tools-bin, which the description file is the following (just copies an executable from a git repository):

package("sokol-tools-bin")
    set_kind("library", {binary = true})
    add_urls("https://github.com/floooh/sokol-tools-bin.git")
    on_install("windows", function (package)
        os.cp("bin/win32/sokol-shdc.exe", package:installdir("bin"))
    end)

Now I'm trying to create a custom rule to invoke sokol-shdc for all files with the *.glsl extension. I need a nice and easy way to find where "sokol-shdc.exe" is installed in my system, so naturally I use find_package() to get the install directory of the sokol-tools-bin package.

rule("sokol_shaders")
	set_extensions(".glsl")
	on_load(function (target)
		target:add("includedirs", target:autogendir())
	end)
	before_buildcmd_file(function (target, batchcmds, shaderfile, opt)
		import("lib.detect.find_package")

		local headerdir = target:autogendir()
		local name = path.basename(shaderfile)
		local ext = path.extension(shaderfile)
		local headerfile = path.join(headerdir, string.format("%s.%s.h", name, ext))

		local package = find_package("sokol-tools-bin")
		local binary = path.join(package:installdir("bin"), "sokol-shdc.exe")

		batchcmds:show_progress(opt.progress, "${color.build.object}generating headers for %s", shaderfile)
		batchcmds:vrunv(binary, "--input", shaderfile, "--output", headerfile, "--slang", "glsl330:hlsl5:metal_macos")
		batchcmds:add_depfiles(shaderfile)
		batchcmds:set_depmtime(os.mtime(headerfile))
		batchcmds:set_depcache(target:dependfile(headerfile))
	end)
rule_end()

Then I apply this rule to my target:

target("renderer_test")
	add_rules("sokol_shaders")
	set_kind("binary")
	add_files("renderer/*.cpp")
	add_files("renderer/shaders/*.glsl")
	add_includedirs("renderer")
	add_packages("opengl", "sokol", "sokol-tools-bin")

The problem is, find_package("sokol-tools-bin") returns nil and xmake gives out an error. I'm suspecting the reason for this is that the packages for the target renderer_test are added later than before_buildcmd_file() callback is called. Is there a better way to find the path of an installed package?

[waruqi]

why do not use bin2c or glsl2spv rules?

https://xmake.io/#/manual/custom_rule?id=utilsbin2c
https://xmake.io/#/manual/custom_rule?id=utilsglsl2spv

or you can refer https://github.com/xmake-io/xmake/blob/master/xmake/rules/utils/glsl2spv/xmake.lua

[waruqi]

sokol-shdc does a bit more than what bin2c and glsl2spv does. It converts a GLSL-like shader code to whatever format you need depending on the rendering backend (GLSL, HLSL, Metal Shading Language, ...), and is tailor-made to work with sokol (https://github.com/floooh/sokol).

so you can refer https://github.com/xmake-io/xmake/blob/master/xmake/rules/utils/glsl2spv/xmake.lua and improve your rule.

The code for glsl2spv that you've linked also has the same problem as what I have currently: it assumes that glslangValidator (or glslc) is installed on the system. Ideally for user convenience, it would be better if a xmake package named glslangValidator-bin provided the executable, and the glsl2spv rule can use the binary from that package. In that way the user doesn't need to install glslangValidator separately from xmake.

no, we will add glslang package, it will add glslangValidator bin path to $PATH.

add_requires("glslang", {configs = {binaryonly = true}})
target("test")
     add_rules("utils.glsl2spv")
     add_packages("glslang")

glslang package will find glslangValidator on system and add bin path, it will install it automatically if not found.

[lasagnaphil]

Is there a way to use the glslangValidator binary from that package without adding to the $PATH? I would like to keep the environment variables as clean as possible, since multiple projects can possibly use different versions of the glslangValidator executable.

[waruqi]

Is there a way to use the glslangValidator binary from that package without adding to the $PATH? I would like to keep the environment variables as clean as possible, since multiple projects can possibly use different versions of the glslangValidator executable.

add_packages("glslang") just add to $PATH in given target. only for their rules environment (on_xxx, before_xxx, after_xxx), so it's very clean.

you can add different version of glslang package to the different targets.

[waruqi]

add_requires("glslang 1.0", {configs = {binaryonly = true}, alias = "glslang1x"})
add_requires("glslang 2.0", {configs = {binaryonly = true}, alias = "glslang2x"})

target("test")
     add_rules("utils.glsl2spv")
     add_packages("glslang1x")

target("test2")
     add_rules("utils.glsl2spv")
     add_packages("glslang2x")

[lasagnaphil]

Understood. I think I would be able to do what I want by following the code for glsl2spv. Thanks for all the hard work!