refactor msvc module infrastructure

3 files changed, 633 insertions, 0 deletions

diff --git a/xmake/rules/c++/modules/modules_support/msvc/builder.lua b/xmake/rules/c++/modules/modules_support/msvc/builder.lua
new file mode 100644
index 000000000..0f4f9b735
--- /dev/null
+++ b/xmake/rules/c++/modules/modules_support/msvc/builder.lua
@@ -0,0 +1,322 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-present, TBOOX Open Source Group.
+--
+-- @author      ruki, Arthapz
+-- @file        msvc/builder.lua
+--
+
+-- imports
+import("core.base.json")
+import("core.base.option")
+import("core.base.semver")
+import("utils.progress")
+import("private.action.build.object", {alias = "objectbuilder"})
+import("core.tool.compiler")
+import("core.project.config")
+import("core.project.depend")
+import("private.tools.vstool")
+import("compiler_support")
+import(".builder", {inherit = true})
+
+-- get flags for building a module
+function _make_modulebuildflags(target, provide, bmifile, sourcefile, objectfile, opt)
+
+    -- get flags
+    local ifcoutputflag = compiler_support.get_ifcoutputflag(target)
+    local ifconlyflag = compiler_support.get_ifconlyflag(target)
+    local interfaceflag = compiler_support.get_interfaceflag(target)
+    local internalpartitionflag = compiler_support.get_internalpartitionflag(target)
+
+    local objectfile_or_ifconlyflag = (opt.external and ifconlyflag) and ifconlyflag or "-Fo" .. objectfile
+
+    local flags
+    if provide then -- named module
+        flags = {"-TP", ifcoutputflag, bmifile, provide.interface and interfaceflag or internalpartitionflag, objectfile_or_ifconlyflag, "-c", sourcefile}
+    else
+        flags = {"-TP", objectfile_or_ifconlyflag, "-c", sourcefile}
+    end
+
+    return flags
+end
+
+-- get flags for building a headerunit
+function _make_headerunitflags(target, headerunit, bmifile, opt)
+
+    -- get flags
+    local exportheaderflag = compiler_support.get_exportheaderflag(target)
+    local headernameflag = compiler_support.get_headernameflag(target)
+    local ifcoutputflag = compiler_support.get_ifcoutputflag(target)
+    assert(headernameflag and exportheaderflag, "compiler(msvc): does not support c++ header units!")
+
+    local local_directory = (headerunit.type == ":quote") and {"-I" .. path.directory(headerunit.path)} or {}
+
+    local flags = table.join(local_directory, {"-TP", 
+                                               exportheaderflag,
+                                               headernameflag .. headerunit.type,
+                                               ifcoutputflag,
+                                               bmifile,
+                                               headerunit.type == ":angle" and headerunit.name or headerunit.path})
+    return flags
+end
+
+-- do compile
+function _compile(target, flags, sourcefile)
+
+    local dryrun = option.get("dry-run")
+    local compinst = target:compiler("cxx")
+    local compflags = compinst:compflags({sourcefile = sourcefile, target = target})
+    local msvc = target:toolchain("msvc")
+    local flags = table.join(compflags or {}, flags)
+
+    -- trace
+    vprint(compinst:program(), table.unpack(flags))
+
+    if not dryrun then
+        -- do compile
+        assert(os.iorunv(compinst:program(), flags, {envs = msvc:runenvs()}))
+    end
+end
+
+-- do compile for batchcmds
+-- @note we need to use batchcmds:compilev to translate paths in compflags for generator, e.g. -Ixx
+function _batchcmds_compile(batchcmds, target, flags, sourcefile)
+
+    local compinst = target:compiler("cxx")
+    local compflags = compinst:compflags({sourcefile = sourcefile, target = target})
+    batchcmds:compilev(table.join(compflags or {}, flags), {compiler = compinst, sourcekind = "cxx"})
+end
+
+-- get module requires flags
+-- e.g
+-- /reference Foo=build/.gens/Foo/rules/modules/cache/Foo.ifc
+-- /headerUnit:angle glm/mat4x4.hpp=Users\arthu\AppData\Local\.xmake\packages\g\glm\0.9.9+8\91454f3ee0be416cb9c7452970a2300f\include\glm\mat4x4.hpp.ifc
+--
+function _get_requiresflags(target, module, opt)
+
+    local referenceflag = compiler_support.get_referenceflag(target)
+    local headerunitflag = compiler_support.get_headerunitflag(target)
+
+    local name = module.name
+    local cachekey = target:name() .. name
+
+    local requiresflags = compiler_support.memcache():get2(cachekey, "requiresflags")
+                         or compiler_support.localcache():get2(cachekey, "requiresflags")
+    if not requiresflags or (opt and opt.regenerate) then
+        local deps_flags = {}
+        for required, _ in pairs(module.requires) do
+            local dep_module = get_from_target_mapper(target, required)
+
+            assert(dep_module, "module dependency %s required for %s not found <%s>", required, name, target:name())
+
+            local bmifile = dep_module.bmi
+            local mapflag = {dep_module.headerunit and headerunitflag .. dep_module.headerunit.type or referenceflag, required .. "=" .. bmifile}
+            table.insert(deps_flags, mapflag)
+
+            -- append deps
+            if dep_module.opt and dep_module.opt.deps then
+                local deps = _get_requiresflags(target, { name = dep_module.name or dep_module.sourcefile, bmi = bmifile, requires = dep_module.opt.deps })
+                table.join2(deps_flags, deps)
+            end
+        end
+
+        requiresflags = {}
+        -- remove duplicates
+        local contains = {}
+        for _, map in ipairs(deps_flags) do
+            local name, _ = map[2]:split("=")[1], map[2]:split("=")[2]
+            if not contains[name] then
+                table.insert(requiresflags, map)
+                contains[name] = true
+            end
+        end
+        compiler_support.memcache():set2(cachekey, "requiresflags", requiresflags)
+        compiler_support.localcache():set2(cachekey, "requiresflags", requiresflags)
+    end
+
+    return requiresflags
+end
+
+function _append_requires_flags(target, module, name, cppfile, bmifile, opt)
+    local cxxflags = {}
+    local requiresflags = _get_requiresflags(target, {name = (name or cppfile), bmi = bmifile, requires = module.requires}, {regenerate = opt.build})
+
+    for _, flag in ipairs(requiresflags) do
+        -- we need to wrap flag to support flag with space
+        if type(flag) == "string" and flag:find(" ", 1, true) then
+            table.insert(cxxflags, {flag})
+        else
+            table.insert(cxxflags, flag)
+        end
+    end
+    target:fileconfig_add(cppfile, {force = {cxxflags = cxxflags}})
+end
+
+-- populate module map 
+function populate_module_map(target, modules)
+    for _, module in pairs(modules) do
+        local name, provide, cppfile = compiler_support.get_provided_module(module)
+        if provide then
+            local bmifile = compiler_support.get_bmi_path(provide.bmi)
+            add_module_to_target_mapper(target, name, cppfile, bmifile, {deps = module.requires})
+        end
+    end
+end
+
+-- get defines for a module
+function get_module_required_defines(target, sourcefile)
+    local compinst = compiler.load("cxx", {target = target})
+    local compflags = compinst:compflags({sourcefile = sourcefile, target = target})
+    local defines
+
+    for _, flag in ipairs(compflags) do
+        if flag:startswith("-D") or flag:startswith("/D") then
+            defines = defines or {}
+            table.insert(defines, flag:sub(3))
+        end
+    end
+
+    return defines
+end
+
+-- build module file for batchjobs
+function make_module_build_job(target, batchjobs, job_name, deps, opt)
+
+    local name, provide, _ = compiler_support.get_provided_module(opt.module)
+    local bmifile = provide and compiler_support.get_bmi_path(provide.bmi)
+    local dryrun = option.get("dry-run")
+    local populate_job_name = get_modulemap_populate_jobname(target)
+
+    return {
+        name = job_name,
+        deps = table.join({populate_job_name}, deps),
+        sourcefile = opt.cppfile,
+        job = batchjobs:newjob(name or opt.cppfile, function(index, total)
+
+            local compinst = compiler.load("cxx", {target = target})
+            local compflags = compinst:compflags({sourcefile = opt.cppfile, target = target})
+
+            -- append requires flags
+            if opt.module.requires then
+                _append_requires_flags(target, opt.module, name, opt.cppfile, bmifile, opt)
+            end
+
+            local dependfile = target:dependfile(bmifile or opt.objectfile)
+            local dependinfo = depend.load(dependfile) or {}
+            dependinfo.files = {}
+            local depvalues = {compinst:program(), compflags}
+
+            -- compile if it's a named module
+            if opt.build and (provide or compiler_support.has_module_extension(opt.cppfile)) then
+                progress.show((index * 100) / total, "${color.build.target}<%s> ${clear}${color.build.object}compiling.module.$(mode) %s", target:name(), name or opt.cppfile)
+
+                if not dryrun then
+                    local objectdir = path.directory(opt.objectfile)
+                    if not os.isdir(objectdir) then
+                        os.mkdir(objectdir)
+                    end
+                end
+
+                local fileconfig = target:fileconfig(opt.cppfile)
+                local external = fileconfig and fileconfig.external
+                local flags = _make_modulebuildflags(target, provide, bmifile, opt.cppfile, opt.objectfile, {external = external})
+
+                _compile(target, flags, opt.cppfile)
+            end
+
+            table.insert(dependinfo.files, opt.cppfile)
+            dependinfo.values = depvalues
+            depend.save(dependinfo, dependfile)
+        end)}
+end
+
+-- build module file for batchcmds
+function make_module_build_cmds(target, batchcmds, opt)
+
+    local name, provide, _ = compiler_support.get_provided_module(opt.module)
+    local bmifile = provide and compiler_support.get_bmi_path(provide.bmi)
+
+    -- append requires flags
+    if opt.module.requires then
+        _append_requires_flags(target, opt.module, name, opt.cppfile, bmifile, opt)
+    end
+
+    if opt.build then
+        if provide or compiler_support.has_module_extension(opt.cppfile) then
+            batchcmds:show_progress(opt.progress, "${color.build.target}<%s> ${clear}${color.build.object}compiling.module.$(mode) %s", target:name(), name or opt.cppfile)
+            batchcmds:mkdir(path.directory(opt.objectfile))
+
+            local fileconfig = target:fileconfig(opt.cppfile)
+                local external = fileconfig and fileconfig.external
+            local flags = _make_modulebuildflags(target, provide, bmifile, opt.cppfile, opt.objectfile, {batchcmds = true, external = external})
+            _batchcmds_compile(batchcmds, target, flags, opt.cppfile)
+        end
+    end
+    batchcmds:add_depfiles(opt.cppfile)
+
+   return os.mtime(opt.objectfile)
+end
+
+-- build headerunit file for batchjobs
+function make_headerunit_build_job(target, job_name, batchjobs, headerunit, bmifile, outputdir, opt)
+
+    local already_exists = add_headerunit_to_target_mapper(target, headerunit, bmifile)
+    if not already_exists then
+        return {
+            name = job_name,
+            sourcefile = headerunit.path,
+            job = batchjobs:newjob(job_name, function(index, total)
+                if not os.isdir(outputdir) then
+                    os.mkdir(outputdir)
+                end
+
+                local compinst = compiler.load("cxx", {target = target})
+                local compflags = compinst:compflags({sourcefile = headerunit.path, target = target})
+
+                local dependfile = target:dependfile(bmifile)
+                local dependinfo = depend.load(dependfile) or {}
+                dependinfo.files = {}
+                local depvalues = {compinst:program(), compflags}
+
+                local name = headerunit.unique and headerunit.name or headerunit.path
+
+                if opt.build then
+                    progress.show((index * 100) / total, "${color.build.target}<%s> ${clear}${color.build.object}compiling.headerunit.$(mode) %s", target:name(), headerunit.name)
+                    _compile(target, _make_headerunitflags(target, headerunit, bmifile, {}), name, target:objectfile(headerunit.path), true)
+                end
+
+                table.insert(dependinfo.files, headerunit.path)
+                dependinfo.values = depvalues
+                depend.save(dependinfo, dependfile)
+            end)}
+    end
+end
+
+-- build headerunit file for batchcmds
+function make_headerunit_build_cmds(target, batchcmds, headerunit, bmifile, outputdir, opt)
+
+    batchcmds:mkdir(outputdir)
+
+    add_headerunit_to_target_mapper(target, headerunit, bmifile)
+
+    if opt.build then
+        local name = headerunit.unique and headerunit.name or headerunit.path
+        batchcmds:show_progress(opt.progress, "${color.build.target}<%s> ${clear}${color.build.object}compiling.headerunit.$(mode) %s", target:name(), name)
+        _batchcmds_compile(batchcmds, target, _make_headerunitflags(target, headerunit, bmifile, {batchcmds = true, bmifile = bmifile}))
+    end
+    batchcmds:add_depfiles(headerunit.path)
+    return os.mtime(bmifile)
+end
+
diff --git a/xmake/rules/c++/modules/modules_support/msvc/compiler_support.lua b/xmake/rules/c++/modules/modules_support/msvc/compiler_support.lua
new file mode 100644
index 000000000..3b6aafb9a
--- /dev/null
+++ b/xmake/rules/c++/modules/modules_support/msvc/compiler_support.lua
@@ -0,0 +1,239 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-present, TBOOX Open Source Group.
+--
+-- @author      ruki, Arthapz
+-- @file        msvc/compiler_support.lua
+--
+
+-- imports
+import("core.base.semver")
+import("core.project.config")
+import("lib.detect.find_tool")
+import(".compiler_support", {inherit = true})
+
+-- load module support for the current target
+function load(target)
+
+    local msvc = target:toolchain("msvc")
+    local vcvars = msvc:config("vcvars")
+
+    -- enable std modules if c++23 by defaults
+    if target:data("c++.msvc.enable_std_import") == nil then
+        local languages = target:get("languages")
+        local isatleastcpp23 = false
+        for _, language in ipairs(languages) do
+            if language:startswith("c++") or language:startswith("cxx") then
+                isatleastcpp23 = true
+                local version = tonumber(language:match("%d+"))
+                if (not version or version <= 20) and not language:match("latest") then
+                    isatleastcpp23 = false
+                    break
+                end
+            end
+        end
+        local stdmodulesdir
+        local msvc = target:toolchain("msvc")
+        if msvc then
+            local vcvars = msvc:config("vcvars")
+            if vcvars.VCInstallDir and vcvars.VCToolsVersion and semver.compare(vcvars.VCToolsVersion, "14.35") > 0 then
+                stdmodulesdir = path.join(vcvars.VCInstallDir, "Tools", "MSVC", vcvars.VCToolsVersion, "modules")
+            end
+        end
+        target:data_set("c++.msvc.enable_std_import", isatleastcpp23 and os.isdir(stdmodulesdir))
+    end
+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")
+            if vcvars.VCInstallDir and vcvars.VCToolsVersion then
+                return { path.join(vcvars.VCInstallDir, "Tools", "MSVC", vcvars.VCToolsVersion, "include") }
+            end
+            break
+        end
+    end
+    raise("msvc toolchain includedirs not found!")
+end
+
+function get_stdmodules(target)
+    -- build c++23 standard modules if needed
+    if target:data("c++.msvc.enable_std_import") 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")
+                assert(stdmodulesdir, "Can't enable C++23 std modules, directory missing !")
+
+                return {path.join(stdmodulesdir, "std.ixx"), path.join(stdmodulesdir, "std.compat.ixx")}
+            end
+        end
+    end
+end
+
+function get_bmi_extension()
+    return ".ifc"
+end
+
+function get_ifcoutputflag(target)
+    local ifcoutputflag = _g.ifcoutputflag
+    if ifcoutputflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags({"-ifcOutput", os.tmpfile()}, "cxxflags", {flagskey = "cl_ifc_output"})  then
+            ifcoutputflag = "-ifcOutput"
+        end
+        assert(ifcoutputflag, "compiler(msvc): does not support c++ module flag(/ifcOutput)!")
+        _g.ifcoutputflag = ifcoutputflag or false
+    end
+    return ifcoutputflag or nil
+end
+
+function get_ifconlyflag(target)
+    local ifconlyflag = _g.ifconlyflag
+    if ifconlyflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags({"-ifcOnly"}, "cxxflags", {flagskey = "cl_ifc_only"})  then
+            ifconlyflag = "-ifcOnly"
+        end
+        _g.ifconlyflag = ifconlyflag or false
+    end
+    return ifconlyflag or nil
+end
+
+function get_ifcsearchdirflag(target)
+    local ifcsearchdirflag = _g.ifcsearchdirflag
+    if ifcsearchdirflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags({"-ifcSearchDir", os.tmpdir()}, "cxxflags", {flagskey = "cl_ifc_search_dir"})  then
+            ifcsearchdirflag = "-ifcSearchDir"
+        end
+        assert(ifcsearchdirflag, "compiler(msvc): does not support c++ module flag(/ifcSearchDir)!")
+        _g.ifcsearchdirflag = ifcsearchdirflag or false
+    end
+    return ifcsearchdirflag or nil
+end
+
+function get_interfaceflag(target)
+    local interfaceflag = _g.interfaceflag
+    if interfaceflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags("-interface", "cxxflags", {flagskey = "cl_interface"}) then
+            interfaceflag = "-interface"
+        end
+        assert(interfaceflag, "compiler(msvc): does not support c++ module flag(/interface)!")
+        _g.interfaceflag = interfaceflag or false
+    end
+    return interfaceflag
+end
+
+function get_referenceflag(target)
+    local referenceflag = _g.referenceflag
+    if referenceflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags({"-reference", "Foo=" .. os.tmpfile()}, "cxxflags", {flagskey = "cl_reference"}) then
+            referenceflag = "-reference"
+        end
+        assert(referenceflag, "compiler(msvc): does not support c++ module flag(/reference)!")
+        _g.referenceflag = referenceflag or false
+    end
+    return referenceflag or nil
+end
+
+function get_headernameflag(target)
+    local headernameflag = _g.headernameflag
+    if headernameflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags({"-std:c++latest", "-exportHeader", "-headerName:quote"}, "cxxflags", {flagskey = "cl_header_name_quote"}) and
+        compinst:has_flags({"-std:c++latest", "-exportHeader", "-headerName:angle"}, "cxxflags", {flagskey = "cl_header_name_angle"}) then
+            headernameflag = "-headerName"
+        end
+        _g.headernameflag = headernameflag or false
+    end
+    return headernameflag or nil
+end
+
+function get_headerunitflag(target)
+    local headerunitflag = _g.headerunitflag
+    if headerunitflag == nil then
+        local compinst = target:compiler("cxx")
+        local ifcfile = os.tmpfile()
+        if compinst:has_flags({"-std:c++latest", "-headerUnit:quote", "foo.h=" .. ifcfile}, "cxxflags", {flagskey = "cl_header_unit_quote"}) and
+        compinst:has_flags({"-std:c++latest", "-headerUnit:angle", "foo.h=" .. ifcfile}, "cxxflags", {flagskey = "cl_header_unit_angle"}) then
+            headerunitflag = "-headerUnit"
+        end
+        _g.headerunitflag = headerunitflag or false
+    end
+    return headerunitflag or nil
+end
+
+function get_exportheaderflag(target)
+    local exportheaderflag = _g.exportheaderflag
+    if exportheaderflag == nil then
+        if get_headernameflag(target) then
+            exportheaderflag = "-exportHeader"
+        end
+        _g.exportheaderflag = exportheaderflag or false
+    end
+    return exportheaderflag or nil
+end
+
+function get_scandependenciesflag(target)
+    local scandependenciesflag = _g.scandependenciesflag
+    if scandependenciesflag == nil then
+        local compinst = target:compiler("cxx")
+        local scan_dependencies_jsonfile = os.tmpfile() .. ".json"
+        if compinst:has_flags("-scanDependencies " .. scan_dependencies_jsonfile, "cxflags", {flagskey = "cl_scan_dependencies",
+            on_check = function (ok, errors)
+                if os.isfile(scan_dependencies_jsonfile) then
+                    ok = true
+                end
+                if ok and not os.isfile(scan_dependencies_jsonfile) then
+                    ok = false
+                end
+                return ok, errors
+            end}) then
+            scandependenciesflag = "-scanDependencies"
+        end
+        _g.scandependenciesflag = scandependenciesflag or false
+    end
+    return scandependenciesflag or nil
+end
+
+function get_cppversionflag(target)
+    local cppversionflag = _g.cppversionflag
+    if cppversionflag == nil then
+        local compinst = target:compiler("cxx")
+        local flags = compinst:compflags({target = target})
+        cppversionflag = table.find_if(flags, function(v) string.startswith(v, "/std:c++") end) or "/std:c++latest"
+    end
+    return cppversionflag or nil
+end
+
+function get_internalpartitionflag(target)
+    local internalpartitionflag = _g.internalpartitionflag
+    if internalpartitionflag == nil then
+        local compinst = target:compiler("cxx")
+        if compinst:has_flags("-internalPartition", "cxxflags", {flagskey = "cl_internal_partition"}) then
+            internalpartitionflag = "-internalPartition"
+        end
+        _g.internalpartitionflag = internalpartitionflag or false
+    end
+    return internalpartitionflag or nil
+end
diff --git a/xmake/rules/c++/modules/modules_support/msvc/dependency_scanner.lua b/xmake/rules/c++/modules/modules_support/msvc/dependency_scanner.lua
new file mode 100644
index 000000000..ed5027e22
--- /dev/null
+++ b/xmake/rules/c++/modules/modules_support/msvc/dependency_scanner.lua
@@ -0,0 +1,72 @@
+--!A cross-platform build utility based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-present, TBOOX Open Source Group.
+--
+-- @author      ruki, Arthapz
+-- @file        msvc/dependency_scanner.lua
+--
+
+-- imports
+import("core.base.json")
+import("core.base.semver")
+import("core.project.depend")
+import("private.tools.vstool")
+import("utils.progress")
+import("compiler_support")
+import("builder")
+import(".dependency_scanner", {inherit = true})
+
+-- generate dependency files
+function generate_dependencies(target, sourcebatch, opt)
+    local msvc = target:toolchain("msvc")
+    local scandependenciesflag = compiler_support.get_scandependenciesflag(target)
+    local ifcoutputflag = compiler_support.get_ifcoutputflag(target)
+    local common_flags = {"-TP", scandependenciesflag}
+    local changed = false
+
+    for _, sourcefile in ipairs(sourcebatch.sourcefiles) do
+        local dependfile = target:dependfile(sourcefile)
+        depend.on_changed(function ()
+            progress.show(opt.progress, "${color.build.target}<%s> generating.module.deps %s", target:name(), sourcefile)
+            local outputdir = compiler_support.get_outputdir(target, sourcefile)
+
+            local jsonfile = path.join(outputdir, path.filename(sourcefile) .. ".module.json")
+            if scandependenciesflag and not target:policy("build.c++.msvc.fallbackscanner") then
+                local flags = {jsonfile, sourcefile, ifcoutputflag, outputdir, "-Fo" .. target:objectfile(sourcefile)}
+                local compinst = target:compiler("cxx")
+                local msvc = target:toolchain("msvc")
+                local compflags = table.join(compinst:compflags({sourcefile = sourcefile, target = target}) or {}, common_flags, flags)
+                os.vrunv(compinst:program(), winos.cmdargv(compflags), {envs = msvc:runenvs()})
+            else
+                fallback_generate_dependencies(target, jsonfile, sourcefile, function(file)
+                    local compinst = target:compiler("cxx")
+                    local compflags = compinst:compflags({sourcefile = file, target = target})
+                    local ifile = path.translate(path.join(outputdir, path.filename(file) .. ".i"))
+                    os.vrunv(compinst:program(), table.join(compflags,
+                        {"/P", "-TP", file,  "/Fi" .. ifile}), {envs = msvc:runenvs()})
+                    local content = io.readfile(ifile)
+                    os.rm(ifile)
+                    return content
+                end)
+            end
+            changed = true
+
+            local dependinfo = io.readfile(jsonfile)
+            return { moduleinfo = dependinfo }
+        end, {dependfile = dependfile, files = {sourcefile}, changed = target:is_rebuilt()})
+    end
+    return changed
+end
+