Builtin variables and shell

xmake provides the grammar: $(varname) for supporting builtin variable.

.e.g

add_cxflags("-I$(buildir)")

It will translate this variable to the real value when building.

-I$(buildir) => -I./build

We can also use these variables in the custom scripts.

target("test")
    after_build(target)
        print("build ok for $(plat)!")
    end

And the output result is

build ok for macosx!

xmake will get values of these valriables from the cached configure after running xmake config --plat=macosx ...

Also we have some variables which are not in the configure file.

.e.g

print("$(os)")
print("$(host)")
print("$(tmpdir)")
print("$(curdir)")

we can uses these variable for writing xmake.lua more easily.

.e.g

os.cp("$(projectdir)/file", "$(tmpdir)")

vs

-- import project module
import("core.project.project")

-- copy file
os.cp(path.join(project.directory(), "file"), os.tmpdir())

xmake can also run native shell for calling some third-party tools.

.e.g

target("test")
    set_kind("binary")
    if is_plat("linux") then
        add_ldflags("$(shell pkg-config --libs sqlite3)")
    end

Or

target("test")
    set_kind("binary")
    if is_plat("linux") then
        add_linkdir("$(shell find ./ -name lib)")
    end

But often, we do not need to do this. The Lua srcipt has been very powerful : )