(C++ module support) improve jobgraph support

1 files changed, 123 insertions, 0 deletions

diff --git a/xmake/rules/c++/modules/mapper.lua b/xmake/rules/c++/modules/mapper.lua
new file mode 100644
index 000000000..de2bfe572
--- /dev/null
+++ b/xmake/rules/c++/modules/mapper.lua
@@ -0,0 +1,123 @@
+--!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        mapper.lua
+--
+
+import("support")
+import("core.base.hashset")
+
+-- get or create a target module mapper
+function get_mapper_for(target, opt)
+    local localcache = support.localcache()
+    local mapper = localcache:get2(target:fullname(), "module_mapper")
+    local invalidate = opt and opt.invalidate
+    if not mapper or invalidate then
+        mapper = {}
+        localcache:set2(target:fullname(), "module_mapper", mapper)
+    end
+    return mapper
+end
+
+function reuse_modules(target)
+    local localcache = support.localcache()
+    local reused_modules = localcache:get2(target:fullname(), "reused_modules")
+    for key, from_name in pairs(reused_modules) do
+        local dep = target:dep(from_name)
+        assert(dep)
+        support.set_reused(target, dep, key)
+    end
+end
+
+-- feed the module mapper
+function feed(target, modules, sourcefiles)
+
+    local mapper = get_mapper_for(target, {invalidate = true})
+    local localcache = support.localcache()
+    local deps_names = hashset.new()
+    local deps_names_map = {}
+    local headerunit_aliases = {}
+    for _, module in pairs(modules) do
+        if module.headerunit and module.alias then
+            table.insert(headerunit_aliases, module)
+        elseif not module.sourcealias then
+            local name = module.headerunit and (module.name .. module.key) or module.name
+            if name then
+                if name ~= "std" and name ~= "std.compat" and deps_names:has(name) then
+                    raise("duplicate module name detected for \"" .. name .. "\"\n  <" .. target:fullname() .. "> -> " .. module.sourcefile .. "\n  <" .. deps_names_map[name] .. "> -> " .. mapper[name].sourcefile)
+                end
+                deps_names:insert(module.name)
+                deps_names_map[name] = target:fullname()
+                if module.headerunit then
+                    if not mapper[name] then
+                        mapper[name] = module
+                    end
+                else
+                    mapper[name] = module
+                end
+            end
+            if not module.headerunit and not mapper[module.sourcefile] then
+                mapper[module.sourcefile] = table.clone(module)
+                mapper[module.sourcefile].sourcealias = true
+            end
+        end
+    end
+    local reuse = target:policy("build.c++.modules.reuse") or
+                  target:policy("build.c++.modules.tryreuse")
+    -- replace target reused module by dep module
+    if reuse then
+        for _, sourcefile in ipairs(sourcefiles) do
+            local external = support.is_external(target, sourcefile)
+            if external then
+                local reused, from = support.is_reused(target, sourcefile)
+                if reused then
+                    local module = get(from, sourcefile)
+                    mapper[module.name] =  module
+                    for dep_name, dep_module in pairs(module.deps) do
+                        if dep_module.headerunit then
+                            local key = dep_name .. dep_module.key
+                            mapper[key] = get(from, key)
+                            local sourcefile = mapper[key].sourcefile
+                            mapper[sourcefile .. dep_module.key] = table.clone(mapper[key])
+                            mapper[sourcefile .. dep_module.key].alias = false
+                        end
+                    end
+                end
+            end
+        end
+    end
+    -- insert aliases
+    for _, alias in pairs(headerunit_aliases) do
+        local name = alias.name .. alias.key
+        if not mapper[name] then
+            local _module = table.clone(mapper[alias.sourcefile .. alias.key])
+            _module.name = alias.name
+            _module.alias = true
+            mapper[name] = _module
+        end
+    end
+
+    localcache:save()
+end
+
+-- get a module from target mapper by name
+function get(target, name)
+    local mapper = get_mapper_for(target)
+    assert(mapper)
+    return mapper[name]
+end
+