[WIP] Modular C++20 modules

Directory.Build.Props

@@ -52,8 +52,9 @@
       <TreatWarningAsError>true</TreatWarningAsError>
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
-      <LanguageStandard Condition="'$(CppWinRTLanguageStandard)'==''">stdcpp17</LanguageStandard>
+      <LanguageStandard Condition="'$(CppWinRTLanguageStandard)'=='' Or '$(CppWinRTLanguageStandard)'=='17'">stdcpp17</LanguageStandard>
       <LanguageStandard Condition="'$(CppWinRTLanguageStandard)'=='20'">stdcpp20</LanguageStandard>
+      <LanguageStandard Condition="'$(CppWinRTLanguageStandard)'=='latest'">stdcpplatest</LanguageStandard>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <PrecompiledHeaderFile>pch.h</PrecompiledHeaderFile>
       <PreprocessorDefinitions>CPPWINRT_VERSION_STRING="$(CppWinRTBuildVersion)";%(PreprocessorDefinitions)</PreprocessorDefinitions>

cppwinrt/code_writers.h

@@ -37,7 +37,6 @@ namespace cppwinrt
 
     static void write_version_assert(writer& w)
     {
-        w.write_root_include("base");
         auto format = R"(static_assert(winrt::check_version(CPPWINRT_VERSION, "%"), "Mismatched C++/WinRT headers.");
 #define CPPWINRT_VERSION "%"
 )";
@@ -123,6 +122,16 @@ namespace cppwinrt
         return { w, write_endif };
     }
 
+    [[nodiscard]] static finish_with wrap_ifndef(writer& w, std::string_view macro)
+    {
+        auto format = R"(#ifndef %
+)";
+
+        w.write(format, macro);
+
+        return { w, write_endif };
+    }
+
     static void write_parent_depends(writer& w, cache const& c, std::string_view const& type_namespace)
     {
         auto pos = type_namespace.rfind('.');
@@ -145,6 +154,28 @@ namespace cppwinrt
         }
     }
 
+    static void write_parent_imports(writer& w, cache const& c, std::string_view const& type_namespace)
+    {
+        auto pos = type_namespace.rfind('.');
+
+        if (pos == std::string::npos)
+        {
+            return;
+        }
+
+        auto parent = type_namespace.substr(0, pos);
+        auto found = c.namespaces().find(parent);
+
+        if (found != c.namespaces().end() && has_projected_types(found->second))
+        {
+            w.write_import(parent);
+        }
+        else
+        {
+            write_parent_imports(w, c, parent);
+        }
+    }
+
     static void write_pch(writer& w)
     {
         auto format = R"(#include "%"
@@ -313,11 +344,22 @@ namespace cppwinrt
             return;
         }
 
-        if (type_name == "Windows.Foundation.DateTime" ||
-            type_name == "Windows.Foundation.TimeSpan")
+        if (type_name.name_space == "Windows.Foundation")
         {
-            // Don't forward declare these since they're not structs.
-            return;
+            if (type_name.name == "DateTime" ||
+                type_name.name == "TimeSpan")
+            {
+                // Don't forward declare these since they're not structs.
+                return;
+            }
+
+            if (type_name.name == "Point" ||
+                type_name.name == "Rect" ||
+                type_name.name == "Size")
+            {
+                // Don't forward declare these since they're already defined in base.h.
+                return;
+            }
         }
 
         if (type_name.name_space == "Windows.Foundation.Numerics")
@@ -2812,7 +2854,12 @@ struct WINRT_IMPL_EMPTY_BASES produce_dispatch_to_overridable<T, D, %>
         }
     }
 
-    static bool write_structs(writer& w, std::vector<TypeDef> const& types)
+    struct write_structs_result
+    {
+        bool promote = false;
+    };
+
+    static write_structs_result write_structs(writer& w, std::vector<TypeDef> const& types)
     {
         auto format = R"(    struct %
     {
@@ -2829,7 +2876,7 @@ struct WINRT_IMPL_EMPTY_BASES produce_dispatch_to_overridable<T, D, %>
 
         if (types.empty())
         {
-            return false;
+            return {};
         }
 
         struct complex_struct
@@ -2895,7 +2942,7 @@ struct WINRT_IMPL_EMPTY_BASES produce_dispatch_to_overridable<T, D, %>
             }
         }
 
-        bool promote = false;
+        write_structs_result result;
         auto cpp_namespace = w.write_temp("@", w.type_namespace);
 
         for (auto&& type : structs)
@@ -2921,14 +2968,14 @@ struct WINRT_IMPL_EMPTY_BASES produce_dispatch_to_overridable<T, D, %>
                     continue;
                 }
 
-                if (!starts_with(field.second, cpp_namespace))
+                if (!result.promote && !starts_with(field.second, cpp_namespace))
                 {
-                    promote = true;
+                    result.promote = true;
                 }
             }
         }
 
-        return promote;
+        return result;
     }
 
     static void write_class_requires(writer& w, TypeDef const& type)

cppwinrt/cppwinrt.vcxproj

@@ -46,7 +46,6 @@
     <ClInclude Include="..\strings\base_com_ptr.h" />
     <ClInclude Include="..\strings\base_coroutine_foundation.h" />
     <ClInclude Include="..\strings\base_coroutine_system.h" />
-    <ClInclude Include="..\strings\base_coroutine_system_winui.h" />
     <ClInclude Include="..\strings\base_coroutine_threadpool.h" />
     <ClInclude Include="..\strings\base_coroutine_ui_core.h" />
     <ClInclude Include="..\strings\base_deferral.h" />
@@ -56,20 +55,23 @@
     <ClInclude Include="..\strings\base_extern.h" />
     <ClInclude Include="..\strings\base_fast_forward.h" />
     <ClInclude Include="..\strings\base_foundation.h" />
+    <ClInclude Include="..\strings\base_global_fragment.h" />
     <ClInclude Include="..\strings\base_handle.h" />
     <ClInclude Include="..\strings\base_identity.h" />
     <ClInclude Include="..\strings\base_implements.h" />
-    <ClInclude Include="..\strings\base_includes.h" />
     <ClInclude Include="..\strings\base_iterator.h" />
     <ClInclude Include="..\strings\base_lock.h" />
     <ClInclude Include="..\strings\base_macros.h" />
     <ClInclude Include="..\strings\base_marshaler.h" />
     <ClInclude Include="..\strings\base_meta.h" />
     <ClInclude Include="..\strings\base_natvis.h" />
+    <ClInclude Include="..\strings\base_numerics.h" />
     <ClInclude Include="..\strings\base_reference_produce.h" />
     <ClInclude Include="..\strings\base_reference_produce_1.h" />
     <ClInclude Include="..\strings\base_security.h" />
+    <ClInclude Include="..\strings\base_shared.h" />
     <ClInclude Include="..\strings\base_std_hash.h" />
+    <ClInclude Include="..\strings\base_std_includes.h" />
     <ClInclude Include="..\strings\base_string.h" />
     <ClInclude Include="..\strings\base_stringable_format.h" />
     <ClInclude Include="..\strings\base_stringable_streams.h" />

cppwinrt/cppwinrt.vcxproj.filters

@@ -157,9 +157,6 @@
     <ClInclude Include="cmd_reader.h" />
     <ClInclude Include="task_group.h" />
     <ClInclude Include="text_writer.h" />
-    <ClInclude Include="..\strings\base_includes.h">
-      <Filter>strings</Filter>
-    </ClInclude>
     <ClInclude Include="..\strings\base_iterator.h">
       <Filter>strings</Filter>
     </ClInclude>
@@ -178,15 +175,24 @@
     <ClInclude Include="..\strings\base_coroutine_system.h">
       <Filter>strings</Filter>
     </ClInclude>
-    <ClInclude Include="..\strings\base_coroutine_system_winui.h">
-      <Filter>strings</Filter>
-    </ClInclude>
     <ClInclude Include="..\strings\base_xaml_component_connector_winui.h">
       <Filter>strings</Filter>
     </ClInclude>
     <ClInclude Include="..\strings\base_stringable_to_hstring.h">
       <Filter>strings</Filter>
     </ClInclude>
+    <ClInclude Include="..\strings\base_shared.h">
+      <Filter>strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\strings\base_global_fragment.h">
+      <Filter>strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\strings\base_numerics.h">
+      <Filter>strings</Filter>
+    </ClInclude>
+    <ClInclude Include="..\strings\base_std_includes.h">
+      <Filter>strings</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="$(OutDir)version.rc" />