Xrepo how to pass configs to dependent libraries

[cyfdecyf]

Consider following code in CMakeLists.txt which uses xrepo-cmake (Note the problem is not specific to xrepo-cmake):

xrepo_package("gflags" CONFIGS mt=true,shared=true)
xrepo_package("glog" CONFIGS shared=true)

glog depends on gflags, xrepo_package(glog ...) would install a -f mt=false,shared=false build of gflags because these are the default configs for gflags. But this version of config is not needed in the cmake project.

Manual install with xrepo install -f shared=true glog would have the same problem if the user actually wants a shared multi-threading enabled bulid of gflags.

We have builtin and non-builtin configs,

• For builtin configs like shared=true, maybe it's reasonable to pass it recursively to all dependencies.
  • But for builtin flags like cflags, it maybe specific for each package thus shouldn't recursively pass to dependencies.
• For non-builtin configs (mt=true for gflags).

This is a compilcated problem which I don't have any idea to gracefully handle. vcpkg uses baseline (if I understand correctly) which effectively does not allow user to (easily) change package configs.

For now I can live with creating a private repo and take one of the following options:

1. change the mt=true as default for gflags.
2. change the way glog depending on gflags.

Here's the code snippet in gflags's xmake.lua which I changed to take the second option:

for config, dep in pairs(configdeps) do
    if package:config(config) then
        if config == "gflags" then
            package:add("deps", "gflags 2.2.2", {
                configs = {mt = true, shared = package:config("shared")}
            })
        elseif config == "unwind" then
            package:add("deps", "libunwind", {
                configs = {shared = package:config("shared")}
            })
        else
            package:add("deps", dep)
        end
    end
end

It's rather ad-hoc but I doubt if there's any better way to this.

I'm consider adding arrow package in xmake-repo, it depends on lot's of other packages which may require extensive use of passing configs to dependent packages.

[waruqi]

we can use add_requireconfs("glog.gflags", {configs = {mt = true, version = "2.2.2", shared = true}}) if we use xmake in xmake.lua.

but xrepo command does not support it yet.

Maybe we can use the xrepo install command to receive a xmake.lua file to describe all package information. for example:

xrepo install /xxx/glog.lua

/xxx/glog.lua

add_requires("glog")
add_requireconfs("glog.*", {system = false})
add_requireconfs("glog.gflags", {configs = {mt = true, version = "2.2.2", shared = true}})
-- ...

And add an api or option to pass glog.lua to xrepo-cmake wrapper.

xrepo_package("glog" CONFIGS /xxx/glog.lua)

[cyfdecyf]

Maybe we can use the xrepo install command to receive a xmake.lua file to describe all package information. for example:

xrepo install /xxx/glog.lua

/xxx/glog.lua

add_requires("glog")
add_requireconfs("glog.*", {system = false})
add_requireconfs("glog.gflags", {configs = {mt = true, version = "2.2.2", shared = true}})
-- ...

And add an api or option to pass glog.lua to xrepo-cmake wrapper.

xrepo_package("glog" CONFIGS /xxx/glog.lua)

This is a nice way for user to override configs in existing repo.

For xrepo package writers, the provided feature already satisfies the need.

[waruqi]

I have supported it on dev branch.

xrepo install xxx.lua
xrepo fetch xxx.lua

you can improve xrepo-cmake wrapper to support it.