fix package defines handling

tests/projects/c++/modules/packages/my-repo/packages/b/bar/src/bar.cpp

@@ -1,5 +1,5 @@
 #include <a.hpp>
 
-const char *bar() {
+const char *hello() {
     return "Hello world";
 }

tests/projects/c++/modules/packages/my-repo/packages/b/bar/src/bar.mpp

@@ -4,7 +4,9 @@ module;
 
 export module bar;
 
-export {
-  using ::bar;
+export namespace bar {
+const char *hello() {
+     return ::hello();
+}
 }
 

tests/projects/c++/modules/packages/my-repo/packages/b/bar/src/include/a.hpp

@@ -1,6 +1,6 @@
 #ifndef A_HPP
 #define A_HPP
 
-const char *bar();
+[[gnu::visibility("default")]] const char *hello();
 
 #endif

tests/projects/c++/modules/packages/my-repo/packages/b/bar/xmake.lua

@@ -1,8 +1,6 @@
 package("bar")
     set_sourcedir(path.join(os.scriptdir(), "src"))
 
-    add_defines("FOO_EXPORT")
-
     on_install(function(package)
         import("package.tools.xmake").install(package, {})
     end)

tests/projects/c++/modules/packages/my-repo/packages/f/foo/src/xmake.lua

@@ -4,5 +4,4 @@ set_languages("c++20")
 target("foo")
     set_kind("static")
     add_files("*.cpp")
-    add_files("*.mpp", { install = true })
-    add_defines("FOO_EXPORT")
+    add_files("*.mpp", {defines = "FOO_EXPORT", install = true })

tests/projects/c++/modules/packages/src/main.cpp

@@ -2,6 +2,6 @@ import foo;
 import bar;
 
 int main() {
-    foo::say(bar());
+    foo::say(bar::hello());
     return 0;
 }

xmake/rules/c++/modules/modules_support/builder.lua

@@ -147,6 +147,7 @@ end
 --
 -- e.g
 -- {
+--      "defines": ["FOO=BAR"]
 --      "imports": ["std", "bar"]
 --      "name": "foo"
 --      "file": "foo.cppm"
@@ -156,6 +157,9 @@ function _generate_meta_module_info(target, name, sourcefile, requires)
     local modulehash = compiler_support.get_modulehash(target, sourcefile)
     local module_metadata = {name = name, file = path.join(modulehash, path.filename(sourcefile))}
 
+    -- add definitions
+    module_metadata.defines = _builder(target).get_module_required_defines(target, sourcefile)
+
     -- add imports
     if requires then
         for name, _ in pairs(requires) do

xmake/rules/c++/modules/modules_support/clang/builder.lua

@@ -170,6 +170,22 @@ end
 function init_build_for(...)
 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") 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, name, provide, module, cppfile, objectfile, opt)
 

xmake/rules/c++/modules/modules_support/gcc/builder.lua

@@ -321,6 +321,22 @@ function init_build_for(target, batch, modules, opt)
     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") 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, name, provide, module, cppfile, objectfile, opt)
 

xmake/rules/c++/modules/xmake.lua

@@ -79,6 +79,9 @@ rule("c++.build.modules.builder")
                     -- append to sourcebatch
                     for _, package_module_data in pairs(package_modules_data) do
                         table.insert(sourcebatch.sourcefiles, package_module_data.file)
+                        if package_module_data.metadata.defines then
+                            target:fileconfig_add(package_module_data.file, {defines = package_module_data.metadata.defines})
+                        end
                     end
 
                     -- we need to repatch and regenerate dependencies at this point