Merge pull request #6421 from Arthapz/improve-libstdc++-module

(C++ modules support) improve std module support for gcc and clang

9 files changed, 114 insertions, 102 deletions

diff --git a/tests/projects/c++/modules/stdmodules_deps/src/bar.mpp b/tests/projects/c++/modules/stdmodules_deps/src/bar.mpp
index 79d91a393..001cd7c2d 100644
--- a/tests/projects/c++/modules/stdmodules_deps/src/bar.mpp
+++ b/tests/projects/c++/modules/stdmodules_deps/src/bar.mpp
@@ -4,8 +4,11 @@ import std;
 
 export auto my_sum2(std::size_t a, std::size_t b) -> std::size_t;
 
+#if defined(__GNUC__) && !defined(__clang__)
+inline
+#else
 module :private;
-
-auto my_sum2(std::size_t a, std::size_t b) -> std::size_t {
+#endif
+    auto my_sum2(std::size_t a, std::size_t b) -> std::size_t {
   return a + a + b + b;
 }
diff --git a/tests/projects/c++/modules/stdmodules_deps/src/foo.cpp b/tests/projects/c++/modules/stdmodules_deps/src/foo.cpp
new file mode 100644
index 000000000..c1e34dec6
--- /dev/null
+++ b/tests/projects/c++/modules/stdmodules_deps/src/foo.cpp
@@ -0,0 +1,3 @@
+module foo;
+
+auto my_sum(std::size_t a, std::size_t b) -> std::size_t { return a + b; }
diff --git a/tests/projects/c++/modules/stdmodules_deps/src/foo.mpp b/tests/projects/c++/modules/stdmodules_deps/src/foo.mpp
index 17a3795b7..b0aab2fee 100644
--- a/tests/projects/c++/modules/stdmodules_deps/src/foo.mpp
+++ b/tests/projects/c++/modules/stdmodules_deps/src/foo.mpp
@@ -3,9 +3,3 @@ export module foo;
 import std;
 
 export auto my_sum(std::size_t a, std::size_t b) -> std::size_t;
-
-module :private;
-
-auto my_sum(std::size_t a, std::size_t b) -> std::size_t {
-  return a + b;
-}
diff --git a/tests/projects/c++/modules/stdmodules_deps/xmake.lua b/tests/projects/c++/modules/stdmodules_deps/xmake.lua
index 7ee801b8c..6c53ff594 100644
--- a/tests/projects/c++/modules/stdmodules_deps/xmake.lua
+++ b/tests/projects/c++/modules/stdmodules_deps/xmake.lua
@@ -3,6 +3,7 @@ set_languages("c++latest")
 
 target("foo")
     set_kind("static")
+    add_files("src/foo.cpp")
     add_files("src/foo.mpp", {public = true})
 
 target("bar")
diff --git a/tests/projects/c++/modules/test_stdmodules.lua b/tests/projects/c++/modules/test_stdmodules.lua
index d9b25ef56..0ca1cc9de 100644
--- a/tests/projects/c++/modules/test_stdmodules.lua
+++ b/tests/projects/c++/modules/test_stdmodules.lua
@@ -38,21 +38,25 @@ function main(t)
             end
         end
     elseif is_subhost("msys") then
-        -- os.exec("xmake f -c -p mingw --yes")
-        -- _build()
+        local gcc = find_tool("gcc", {version = true})
+        if is_host("linux") and gcc and gcc.version and semver.compare(gcc.version, "15.0") >= 0 then
+            os.exec("xmake f -c -p mingw --yes")
+            _build()
+        end
     elseif is_host("linux") then -- or is_host("macosx") then
-        -- gcc don't support std modules atm
-        -- local gcc = find_tool("gcc", {version = true})
-        -- if is_host("linux") and gcc and gcc.version and semver.compare(gcc.version, "11.0") >= 0 then
-            -- os.exec("xmake f -c --yes")
-            -- _build()
-        -- end
+        local gcc = find_tool("gcc", {version = true})
+        if is_host("linux") and gcc and gcc.version and semver.compare(gcc.version, "15.0") >= 0 then
+            os.exec("xmake f -c --yes")
+            _build()
+        end
         local clang = find_tool("clang", {version = true})
         if clang and clang.version and semver.compare(clang.version, "19.0") >= 0 then
-            -- clang don't support libstdc++ std modules atm
-            -- os.exec("xmake clean -a")
-            -- os.exec("xmake f --toolchain=clang -c --yes")
-            -- _build()
+            local gcc = find_tool("clang", {version = true})
+            if gcc and gcc.version and semver.compare(gcc.version, "15.0") >= 0 then
+                os.exec("xmake clean -a")
+                os.exec("xmake f --toolchain=clang -c --yes")
+                _build()
+            end
             os.exec("xmake clean -a")
             os.exec("xmake f --toolchain=clang --runtimes=c++_shared -c --yes")
             _build()
diff --git a/xmake/core/project/policy.lua b/xmake/core/project/policy.lua
index cad9fd4cd..0c79be649 100644
--- a/xmake/core/project/policy.lua
+++ b/xmake/core/project/policy.lua
@@ -101,7 +101,7 @@ function policy.policies()
             -- If in the future, gcc can support it well, we'll turn it on by default
             -- https://github.com/xmake-io/xmake/issues/3855
             ["build.c++.modules.gcc.cxx11abi"]    = {description = "Force to enable new cxx11 abi in C++ modules for gcc.", type = "boolean"},
-            ["build.c++.gcc.modules.cxx11abi"]    = {description = "Force to enable new cxx11 abi in C++ modules for gcc. (deprecated)", type = "boolean", default = false},
+            ["build.c++.gcc.modules.cxx11abi"]    = {description = "Force to enable new cxx11 abi in C++ modules for gcc. (deprecated)", type = "boolean"},
             -- Set the default vs runtime, e.g. MT, MD
             ["build.c++.msvc.runtime"]            = {description = "Set the default vs runtime.", type = "string", values = {"MT", "MD"}},
             -- Enable cuda device link
diff --git a/xmake/rules/c++/modules/clang/support.lua b/xmake/rules/c++/modules/clang/support.lua
index fd27bcb96..f35796959 100644
--- a/xmake/rules/c++/modules/clang/support.lua
+++ b/xmake/rules/c++/modules/clang/support.lua
@@ -71,7 +71,7 @@ function _get_cpplibrary_name(target)
     elseif target:has_runtime("MD", "MT", "MDd", "MTd") then
         return "msstl"
     end
-    if target:is_plat("macosx") then
+    if target:is_plat("macosx", "iphoneos", "appletvos") then
         return "c++"
     elseif target:is_plat("linux") then
         return "stdc++"
@@ -258,49 +258,42 @@ end
 
 function get_stdmodules(target)
 
-    if target:policy("build.c++.modules.std") then
-        local cpplib = _get_cpplibrary_name(target)
-        if cpplib then
-            if cpplib == "c++" then
-                -- libc++ module is found by parsing libc++.modules.json
-                local modules_json_path = _get_std_module_manifest_path(target)
-                if modules_json_path then
-                    local modules_json = json.decode(io.readfile(modules_json_path))
-                    if modules_json and modules_json.modules and #modules_json.modules > 0 then
-                        local std_module_directory = path.directory(modules_json.modules[1]["source-path"])
-                        if not path.is_absolute(std_module_directory) then
-                            std_module_directory = path.join(path.directory(modules_json_path), std_module_directory)
-                        end
-                        if os.isdir(std_module_directory) then
-                            return {path.normalize(path.join(std_module_directory, "std.cppm")), path.normalize(path.join(std_module_directory, "std.compat.cppm"))}
-                        end
+    if not target:policy("build.c++.modules.std") then
+        return
+    end
+    local cpplib = _get_cpplibrary_name(target)
+    if cpplib then
+        if cpplib == "c++" then
+            -- libc++ module is found by parsing libc++.modules.json
+            local modules_json_path = _get_std_module_manifest_path(target)
+            if modules_json_path then
+                local modules_json = json.decode(io.readfile(modules_json_path))
+                if modules_json and modules_json.modules and #modules_json.modules > 0 then
+                    local std_module_directory = path.directory(modules_json.modules[1]["source-path"])
+                    if not path.is_absolute(std_module_directory) then
+                        std_module_directory = path.join(path.directory(modules_json_path), std_module_directory)
                     end
-                end
-            elseif cpplib == "stdc++" then
-                -- libstdc++ doesn't have a std module file atm
-            elseif cpplib == "msstl" then
-                -- msstl std module file is not compatible with llvm < 19
-                local clang_version = get_clang_version(target)
-                if clang_version and semver.compare(clang_version, "19.0") >= 0 then
-                    local toolchain = target:toolchain("llvm") or target:toolchain("clang") or target:toolchain("clang-cl")
-                    local msvc = import("core.tool.toolchain", {anonymous = true}).load("msvc", {plat = toolchain:plat(), arch = toolchain:arch()})
-                    if msvc and msvc:check({ignore_sdk = true}) then
-                        local vcvars = msvc:config("vcvars")
-                        if vcvars.VCInstallDir and vcvars.VCToolsVersion then
-                            local stdmodulesdir = path.join(vcvars.VCInstallDir, "Tools", "MSVC", vcvars.VCToolsVersion, "modules")
-                            if os.isdir(stdmodulesdir) then
-                                return {path.normalize(path.join(stdmodulesdir, "std.ixx")), path.normalize(path.join(stdmodulesdir, "std.compat.ixx"))}
-                            end
-                        end
+                    if os.isdir(std_module_directory) then
+                        return {path.normalize(path.join(std_module_directory, "std.cppm")), path.normalize(path.join(std_module_directory, "std.compat.cppm"))}
                     end
-                else
-                    wprint("msstl std module file is not compatible with llvm < 19, please upgrade clang/clang-cl version!")
-                    return
                 end
             end
+        elseif cpplib == "stdc++" then
+            -- dont be greedy and don't enable stdc++ std module support for llvm < 19
+            local clang_version = get_clang_version(target)
+            if clang_version and semver.compare(clang_version, "19.0") >= 0 then
+                return import(".gcc.support").get_stdmodules(target)
+            end
+        elseif cpplib == "msstl" then
+            -- msstl std module file is not compatible with llvm < 19
+            local clang_version = get_clang_version(target)
+            if clang_version and semver.compare(clang_version, "19.0") >= 0 then
+                local toolchain = target:toolchain("llvm") or target:toolchain("clang") or target:toolchain("clang-cl")
+                return import(".msvc.support").get_stdmodules(target, {toolchain = toolchain})
+            end
         end
-        wprint("std and std.compat modules not found! maybe try to add --sdk=<PATH/TO/LLVM> or install libc++")
     end
+    wprint("std and std.compat modules not found! maybe try to add --sdk=<PATH/TO/LLVM> or install libc++")
 end
 
 function get_bmi_extension()
diff --git a/xmake/rules/c++/modules/gcc/support.lua b/xmake/rules/c++/modules/gcc/support.lua
index bc924f35c..dd7986475 100644
--- a/xmake/rules/c++/modules/gcc/support.lua
+++ b/xmake/rules/c++/modules/gcc/support.lua
@@ -61,6 +61,13 @@ function load(target)
     -- https://github.com/xmake-io/xmake/issues/3855
     local cxx11abi = target:policy("build.c++.modules.gcc.cxx11abi") or
                      target:policy("build.c++.gcc.modules.cxx11abi")
+    if cxx11abi == nil then
+        -- enable cxx11abi on GCC >= 15 as it is required for C++23 module
+        local gcc_version = get_gcc_version(target)
+        if gcc_version and semver.compare(gcc_version, "15") > 0 then
+            cxx11abi = true
+        end
+    end
     if cxx11abi then
         target:add("cxxflags", "-D_GLIBCXX_USE_CXX11_ABI=1")
     else
@@ -139,10 +146,24 @@ function _get_std_module_manifest_path(target)
             return modules_json_path
         end
     end
-    -- fallback on custom detection
-    -- manifest can be found alongside libstdc++.so
-
-    -- TODO
+    local ext = ".so"
+    if target:is_plat("windows", "mingw") then
+        ext = ".dll"
+    elseif target:is_plat("macosx", "iphoneos", "appletvos") then
+        ext = ".dylib"
+    end
+    local stdcpp_libfile, _ = try {
+        function()
+            return os.iorunv(compinst:program(), {"-print-file-name=libstdc++" .. ext}, {envs = compinst:runenvs()})
+        end
+    }
+    if stdcpp_libfile then
+        modules_json_path = path.join(path.directory(stdcpp_libfile), "libstdc++.modules.json")
+        modules_json_path = modules_json_path:trim()
+        if os.isfile(modules_json_path) then
+            return modules_json_path
+        end
+    end
 end
 
 function get_stdmodules(target)
@@ -150,22 +171,22 @@ function get_stdmodules(target)
         return
     end
     local modules_json_path = _get_std_module_manifest_path(target)
-    if not modules_json_path then
-        return
-    end
-    local modules_json = json.loadfile(modules_json_path)
-    if modules_json and modules_json.modules and #modules_json.modules > 0 then
-        local std_module_files = {}
-        local modules_json_dir = path.directory(modules_json_path)
-        for _, module_file in ipairs(modules_json.modules) do
-            local module_file_path = module_file["source-path"]
-            if not path.is_absolute(module_file_path) then
-                module_file_path = path.join(modules_json_dir, module_file_path)
+    if modules_json_path then
+        local modules_json = json.loadfile(modules_json_path)
+        if modules_json and modules_json.modules and #modules_json.modules > 0 then
+            local std_module_files = {}
+            local modules_json_dir = path.directory(modules_json_path)
+            for _, module_file in ipairs(modules_json.modules) do
+                local module_file_path = module_file["source-path"]
+                if not path.is_absolute(module_file_path) then
+                    module_file_path = path.join(modules_json_dir, module_file_path)
+                end
+                table.insert(std_module_files, path.normalize(module_file_path))
             end
-            table.insert(std_module_files, module_file_path)
+            return std_module_files
         end
-        return std_module_files
     end
+    wprint("std and std.compat modules not found! maybe try to add --sdk=<PATH/TO/LLVM> or install libc++")
 end
 
 function get_bmi_extension()
diff --git a/xmake/rules/c++/modules/msvc/support.lua b/xmake/rules/c++/modules/msvc/support.lua
index f8a6ca3c4..41c5cd44e 100644
--- a/xmake/rules/c++/modules/msvc/support.lua
+++ b/xmake/rules/c++/modules/msvc/support.lua
@@ -20,6 +20,7 @@
 
 -- imports
 import("core.base.semver")
+import("core.tool.toolchain")
 import("core.project.config")
 import("lib.detect.find_tool")
 import(".support", {inherit = true})
@@ -99,7 +100,6 @@ end
 
 -- provide toolchain include dir for stl headerunit when p1689 is not supported
 function toolchain_includedirs(target)
-
     for _, toolchain_inst in ipairs(target:toolchains()) do
         if toolchain_inst:name() == "msvc" then
             local vcvars = toolchain_inst:config("vcvars")
@@ -117,24 +117,27 @@ function has_two_phase_compilation_support(_)
 end
 
 -- build c++23 standard modules if needed
-function get_stdmodules(target)
-
-    if target:policy("build.c++.modules.std") then
-        local msvc = target:toolchain("msvc")
-        if msvc then
-            local vcvars = msvc:config("vcvars")
-            if vcvars.VCInstallDir and vcvars.VCToolsVersion then
-                modules = {}
-
-                local stdmodulesdir = path.join(vcvars.VCInstallDir, "Tools", "MSVC", vcvars.VCToolsVersion, "modules")
-
-                if os.isdir(stdmodulesdir) then
-                    return {path.normalize(path.join(stdmodulesdir, "std.ixx")), path.normalize(path.join(stdmodulesdir, "std.compat.ixx"))}
-                end
+function get_stdmodules(target, opt)
+    opt = opt or {}
+    if not target:policy("build.c++.modules.std") then
+        return
+    end
+    local msvc
+    if opt.toolchain then
+        msvc = toolchain.load("msvc", {plat = opt.toolchain:plat(), arch = opt.toolchain:arch()})
+    else
+        msvc = target:toolchain("msvc")
+    end
+    if msvc and msvc:check() then
+        local vcvars = msvc:config("vcvars")
+        if vcvars.VCInstallDir and vcvars.VCToolsVersion then
+            local stdmodulesdir = path.join(vcvars.VCInstallDir, "Tools", "MSVC", vcvars.VCToolsVersion, "modules")
+            if os.isdir(stdmodulesdir) then
+                return {path.normalize(path.join(stdmodulesdir, "std.ixx")), path.normalize(path.join(stdmodulesdir, "std.compat.ixx"))}
             end
         end
-        wprint("std and std.compat modules not found! disabling them for the build")
     end
+    wprint("std and std.compat modules not found! disabling them for the build")
 end
 
 function get_bmi_extension()
@@ -142,7 +145,6 @@ function get_bmi_extension()
 end
 
 function get_ifcoutputflag(target)
-
     local ifcoutputflag = _g.ifcoutputflag
     if ifcoutputflag == nil then
         local compinst = target:compiler("cxx")
@@ -156,7 +158,6 @@ function get_ifcoutputflag(target)
 end
 
 function get_ifconlyflag(target)
-
     local ifconlyflag = _g.ifconlyflag
     if ifconlyflag == nil then
         local compinst = target:compiler("cxx")
@@ -169,7 +170,6 @@ function get_ifconlyflag(target)
 end
 
 function get_interfaceflag(target)
-
     local interfaceflag = _g.interfaceflag
     if interfaceflag == nil then
         local compinst = target:compiler("cxx")
@@ -183,7 +183,6 @@ function get_interfaceflag(target)
 end
 
 function get_referenceflag(target)
-
     local referenceflag = _g.referenceflag
     if referenceflag == nil then
         local compinst = target:compiler("cxx")
@@ -197,7 +196,6 @@ function get_referenceflag(target)
 end
 
 function get_headernameflag(target)
-
     local headernameflag = _g.headernameflag
     if headernameflag == nil then
         local compinst = target:compiler("cxx")
@@ -211,7 +209,6 @@ function get_headernameflag(target)
 end
 
 function get_headerunitflag(target)
-
     local headerunitflag = _g.headerunitflag
     if headerunitflag == nil then
         local compinst = target:compiler("cxx")
@@ -226,7 +223,6 @@ function get_headerunitflag(target)
 end
 
 function get_exportheaderflag(target)
-
     local exportheaderflag = _g.exportheaderflag
     if exportheaderflag == nil then
         if get_headernameflag(target) then
@@ -238,7 +234,6 @@ function get_exportheaderflag(target)
 end
 
 function get_scandependenciesflag(target)
-
     local scandependenciesflag = _g.scandependenciesflag
     if scandependenciesflag == nil then
         local compinst = target:compiler("cxx")
@@ -261,7 +256,6 @@ function get_scandependenciesflag(target)
 end
 
 function get_cppversionflag(target)
-
     local cppversionflag = _g.cppversionflag
     if cppversionflag == nil then
         local compinst = target:compiler("cxx")
@@ -272,7 +266,6 @@ function get_cppversionflag(target)
 end
 
 function get_internalpartitionflag(target)
-
     local internalpartitionflag = _g.internalpartitionflag
     if internalpartitionflag == nil then
         local compinst = target:compiler("cxx")