star-hengxing
commented
1 month ago Please use set_kind("moduleonly")
Open iDingDong opened 1 month ago
star-hengxing
commented
1 month ago Please use set_kind("moduleonly")
waruqi
commented
1 month ago 如果没有 .cpp 只要纯 module 文件，得用 moduleonly 而不是 static
iDingDong
commented
1 month ago Please use
set_kind("moduleonly")
That would not produce a static library for me. Is it impossible to build a static library that exports modules?
waruqi
commented
1 month ago iDingDong
commented
1 month ago see #4707 (comment)
This comment doesn't make sense. Module units do get built into .lib at least for MSVC.
iDingDong
commented
1 month ago You can easily produce a huge static library by exporting large global variables that is not zero-initialized. For example, Visual studio would produce a 9KB+ static library containing only the following module unit.
export module Module;
import std;
struct A {
int i = 123;
};
export constinit std::array<A, 1000000> ExportedArray = {};@Arthapz
Issues-translate-bot
commented
1 month ago Bot detected the issue body's language is not English, translate it automatically.
@arthapaj
Arthapz
commented
1 month ago You can easily produce a huge static library by exporting large global variables that is not zero-initialized. For example, Visual studio would produce a 9KB+ static library containing only the following module unit.
export module Module; import std; struct A { int i = 123; }; export constinit std::array<A, 1000000> ExportedArray = {};
and it work (but i get a 4KB static library :D)
Arthapz
commented
1 month ago as for your first example, i think the module get culled as it import and export nothing, we should add a proper error
but if ur static library only contains named module, u should use moduleonly targetkind to avoid flag compatibility issues with the consumer
iDingDong
commented
1 month ago You can easily produce a huge static library by exporting large global variables that is not zero-initialized. For example, Visual studio would produce a 9KB+ static library containing only the following module unit.
export module Module; import std; struct A { int i = 123; }; export constinit std::array<A, 1000000> ExportedArray = {};and it work (but i get a 4KB static library :D)
Size doesn't matter as long as it is reasonably larger than an empty library. It could be affected by other configurations.
Latest xmake would compile it but failed to resolve dependencies when another target attempt to add the library as its dependency and imports the module.
as for your first example, i think the module get culled as it import and export nothing, we should add a proper error
The initial example serves as a minimal repro case which does not really need to define another symbol to make itself clear.
I do appreciate a warning but an empty lib is prefered than an error.
but if ur static library only contains named module, u should use moduleonly targetkind to avoid flag compatibility issues with the consumer
That kind of problem is not exclusive to modules that any static library built out of old-fashion source/header can be troubled the same way. Since it has never been a legit reason to drop static library support for tranditional sources and switch, modules should be nothing different.
Arthapz
commented
1 month ago u need to flag ur named module as public to get them accessible from other targets and not being culled
target("testm")
set_kind("static")
set_languages("cxxlatest")
add_files("./test.cppm", {public = true})
target_end()by default we cull non-public unreferenced named module (a named module which is netheir imported inside the library or exposed to be consumed) to avoid building unused modules
local objectfiles_sorted_set = hashset.from(objectfiles_sorted)
for _, objectfile in ipairs(objectfiles) do
if not objectfiles_sorted_set:has(objectfile) then
-- cull unreferenced non-public named module but add non-module files and implementation modules
local _, provide, cppfile = compiler_support.get_provided_module(modules[objectfile])
local fileconfig = target:fileconfig(cppfile)
local public = fileconfig and fileconfig.public
if not provide or public then
table.insert(result, objectfile)
end
end
end
return resulthttps://github.com/xmake-io/xmake/pull/5369 i also added a policy to disable project or target wise module culling and a fileconfig entry to disable culling on a file
add_rules("mode.release", "mode.debug")
set_languages("c++20")
-- project wise
-- set_policy("build.c++.modules.culling", false)
target("culling")
set_kind("static")
add_files("src/*.mpp")
-- target wise
set_policy("build.c++.modules.culling", false)target("culling")
set_kind("static")
add_files("src/*.mpp", {cull = false}) -- on filesthis should provide to the user the flexibility to choose what he want, but i don't think it's a good default so please use public visibility in first attempt
and i added a proper warning for culled modules
waruqi
commented
1 month ago Does it work now? try dev again. xmake update -s dev
Xmake Version
2.9.3
Operating System Version and Architecture
Windows 11 23H2
Describe Bug
I attempted to compile the following code with xmake and MSVC:
test.cppmxmake.luaThe command
xmakefailed with the following output:Expected Behavior
The code compiles and gives me
testm.libProject Configuration
testsxm.zip
Additional Information and Error Logs
When compiling with `_vD' xmake outputs: