add namespace for rule

tests/apis/namespace/rule/.gitignore

@@ -0,0 +1,8 @@
+# Xmake cache
+.xmake/
+build/
+
+# MacOS Cache
+.DS_Store
+
+

tests/apis/namespace/rule/src/bar.cpp

@@ -0,0 +1,5 @@
+#include "bar.h"
+
+int sub(int a, int b) {
+    return a - b;
+}

tests/apis/namespace/rule/src/bar.h

@@ -0,0 +1,9 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int sub(int a, int b);
+
+#ifdef __cplusplus
+}
+#endif

tests/apis/namespace/rule/src/foo.cpp

@@ -0,0 +1,5 @@
+#include "foo.h"
+
+int add(int a, int b) {
+    return a + b;
+}

tests/apis/namespace/rule/src/foo.h

@@ -0,0 +1,9 @@
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int add(int a, int b);
+
+#ifdef __cplusplus
+}
+#endif

tests/apis/namespace/rule/src/main.cpp

@@ -0,0 +1,9 @@
+#include "foo.h"
+#include "bar.h"
+#include <iostream>
+
+int main(int argc, char** argv) {
+    std::cout << "add(1, 2) = " << add(1, 2) << std::endl;
+    std::cout << "sub(2, 1) = " << sub(2, 1) << std::endl;
+    return 0;
+}

tests/apis/namespace/rule/test.lua

@@ -0,0 +1,3 @@
+function main()
+    os.exec("xmake -vD")
+end

tests/apis/namespace/rule/xmake.lua

@@ -0,0 +1,37 @@
+add_rules("mode.debug", "mode.release")
+
+rule("rule0")
+    on_load(function (target)
+        target:add("defines", "RULE0")
+    end)
+
+namespace("ns1", function ()
+    rule("rule1")
+        on_load(function (target)
+            target:add("defines", "NS1_RULE1")
+        end)
+
+    target("foo")
+        set_kind("static")
+        add_files("src/foo.cpp")
+        add_rules("rule1")
+
+    namespace("ns2", function()
+        rule("rule2")
+            on_load(function (target)
+                target:add("defines", "NS2_RULE2")
+            end)
+
+        target("bar")
+            set_kind("static")
+            add_files("src/bar.cpp")
+            add_rules("rule2")
+    end)
+
+    target("test")
+        set_kind("binary")
+        add_deps("foo", "ns2::bar")
+        add_files("src/main.cpp")
+        add_rules("rule0", "rule1", "ns2::rule2")
+end)
+

xmake/core/project/project.lua

@@ -383,7 +383,7 @@ function project._load_targets()
         end
         rulenames = table.unique(rulenames)
         for _, rulename in ipairs(rulenames) do
-            local r = project.rule(rulename) or rule.rule(rulename)
+            local r = project.rule(rulename, {namespace = t:namespace()}) or rule.rule(rulename)
             if r then
                 -- only add target rules
                 if r:kind() == "target" then
@@ -1087,8 +1087,13 @@ function project.requireslock_version()
 end
 
 -- get the given rule
-function project.rule(name)
-    return project.rules()[name]
+function project.rule(name, opt)
+    opt = opt or {}
+    local r = project.rules()[name]
+    if r == nil and opt.namespace then
+        r = project.rules()[opt.namespace .. "::" .. name]
+    end
+    return r
 end
 
 -- get project rules

xmake/core/project/rule.lua

@@ -60,12 +60,12 @@ function _instance:_build_deps()
     end
     self._DEPS      = self._DEPS or {}
     self._ORDERDEPS = self._ORDERDEPS or {}
-    instance_deps.load_deps(self, instances, self._DEPS, self._ORDERDEPS, {self:name()})
+    instance_deps.load_deps(self, instances, self._DEPS, self._ORDERDEPS, {self:fullname()})
 end
 
 -- clone rule
 function _instance:clone()
-    local instance = rule.new(self:name(), self._INFO:clone())
+    local instance = rule.new(self:fullname(), self._INFO:clone())
     instance._DEPS = self._DEPS
     instance._ORDERDEPS = self._ORDERDEPS
     instance._PACKAGE = self._PACKAGE
@@ -106,7 +106,23 @@ end
 
 -- set the rule name
 function _instance:name_set(name)
-    self._NAME = name
+    local parts = name:split("::", {plain = true})
+    self._NAME = parts[#parts]
+    table.remove(parts)
+    if #parts > 0 then
+        self._NAMESPACE = table.concat(parts, "::")
+    end
+end
+
+-- get the namespace
+function _instance:namespace()
+    return self._NAMESPACE
+end
+
+-- get the full name
+function _instance:fullname()
+    local namespace = self:namespace()
+    return namespace and namespace .. "::" .. self:name() or self:name()
 end
 
 -- get the rule kind
@@ -331,7 +347,7 @@ end
 function rule.new(name, info, opt)
     opt = opt or {}
     local instance = table.inherit(_instance)
-    instance._NAME = name
+    instance:name_set(name)
     instance._INFO = info
     instance._PACKAGE = opt.package
     if opt.package then

xmake/core/project/target.lua

@@ -75,7 +75,7 @@ end
 function _instance:_load_rule(ruleinst, suffix)
 
     -- init cache
-    local key = ruleinst:name() .. (suffix and ("_" .. suffix) or "")
+    local key = ruleinst:fullname() .. (suffix and ("_" .. suffix) or "")
     local cache = self._RULES_LOADED or {}
 
     -- do load
@@ -90,7 +90,7 @@ function _instance:_load_rule(ruleinst, suffix)
 
         -- before_load has been deprecated
         if on_load and suffix == "before" then
-            deprecated.add(ruleinst:name() .. ".on_load", ruleinst:name() .. ".before_load")
+            deprecated.add(ruleinst:fullname() .. ".on_load", ruleinst:fullname() .. ".before_load")
         end
     end
 
@@ -208,7 +208,7 @@ function _instance:_update_filerules()
     end
     rulenames = table.unique(rulenames)
     for _, rulename in ipairs(rulenames) do
-        local r = target._project() and target._project().rule(rulename) or rule.rule(rulename)
+        local r = target._project() and target._project().rule(rulename, {namespace = self:namespace()}) or rule.rule(rulename)
         if r then
             -- only add target rules
             if r:kind() == "target" then
@@ -1163,7 +1163,11 @@ end
 -- get target rule from the given rule name
 function _instance:rule(name)
     if self._RULES then
-        return self._RULES[name]
+        local r = self._RULES[name]
+        if r == nil and self:namespace() then
+            r = self._RULES[self:namespace() .. "::" .. name]
+        end
+        return r
     end
 end
 
@@ -1173,7 +1177,7 @@ end
 -- it will be replaced in the target:rules() and target:orderules(), but will be not replaced globally in the project.rules()
 function _instance:rule_add(r)
     self._RULES = self._RULES or {}
-    self._RULES[r:name()] = r
+    self._RULES[r:fullname()] = r
     self._ORDERULES = nil
 end
 
@@ -1750,7 +1754,8 @@ function _instance:filerules(sourcefile)
         if filerules then
             override = filerules.override
             for _, rulename in ipairs(table.wrap(filerules)) do
-                local r = target._project().rule(rulename) or rule.rule(rulename) or self:rule(rulename)
+                local r = target._project().rule(rulename, {namespace = self:namespace()}) or
+                            rule.rule(rulename) or self:rule(rulename)
                 if r then
                     table.insert(rules, r)
                 end

xmake/modules/private/utils/rule_groups.lua

@@ -27,7 +27,8 @@ import("core.project.project")
 -- get rule
 -- @note we need to get rule from target first, because we maybe will inject and replace builtin rule in target
 function get_rule(target, rulename)
-    local ruleinst = assert(target:rule(rulename) or project.rule(rulename) or rule.rule(rulename), "unknown rule: %s", rulename)
+    local ruleinst = assert(target:rule(rulename) or project.rule(rulename, {namespace = target:namespace()}) or
+        rule.rule(rulename), "unknown rule: %s", rulename)
     return ruleinst
 end
 

xmake/plugins/project/utils/target_cmds.lua

@@ -64,7 +64,8 @@ function get_target_buildcmd_files(target, cmds, sourcebatch, opt)
 
     -- get rule
     local rulename = assert(sourcebatch.rulename, "unknown rule for sourcebatch!")
-    local ruleinst = assert(target:rule(rulename) or project.rule(rulename) or rule.rule(rulename), "unknown rule: %s", rulename)
+    local ruleinst = assert(target:rule(rulename) or project.rule(rulename, {namespace = target:namespace()}) or
+                        rule.rule(rulename), "unknown rule: %s", rulename)
     local ignored_rules = hashset.from(opt.ignored_rules or {})
     if ignored_rules:has(ruleinst:name()) then
         return