Better control over the order of execution of rules

[waruqi]

Is your feature request related to a problem? Please describe.

Although add_deps("xxx", {order = true}) can also control the order of rules, we can't get it to be executed before some of the built-in rules if it's a user-defined rule.

#2817
#2814

for example: custom cppfront rule will generate .cpp from .cpp2 and it need be call before c++/c++.modules rules.

Describe the solution you'd like

I haven't figured out how to do it yet.

Describe alternatives you've considered

No response

Additional context

No response

[waruqi]

I think it would probably be nice to offer the possibility of rewriting the built-in rules, and we could do other things like adding c++ file extensions and so on, and be able to control the order of dependencies using a consistent approach.

like this.

rule("cppfront")
    set_extensions(".cpp2")
    on_load(function (target)
        -- modify and replace the builtin rule
        local rule = target:rule("c++.build"):clone()
        rule:add("deps", "cppfront", {order = true})
        target:rule_add(rule)
    end)
    on_build_file(function (target, sourcefile, opt)
        print("build cppfront file")
    end)

target("test")
    set_kind("binary")
    add_rules("cppfront")
    add_files("src/*.cpp")
    add_files("src/*.cpp2")

[Arthapz]

I like the clone method, it will provide a better way to handle generated C++ as we don't need anymore to build the files by hand (and it enable c++ module generation)