Trim specializations only used in ignored types

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/Generator/AST/Utils.cs

@@ -147,8 +147,8 @@ namespace CppSharp.AST
             });
         }
 
-        private static bool UnsupportedTemplateArgument(
-            ClassTemplateSpecialization specialization, TemplateArgument a, ITypeMapDatabase typeMaps)
+        public static bool UnsupportedTemplateArgument(this ClassTemplateSpecialization specialization,
+            TemplateArgument a, ITypeMapDatabase typeMaps)
         {
             if (a.Type.Type == null ||
                 IsTypeExternal(
@@ -168,8 +168,7 @@ namespace CppSharp.AST
 
             return (!internalOnly && (((specialization.Ignore ||
                 specialization.TemplatedDecl.TemplatedClass.Ignore) && typeMap == null) ||
-                specialization.Arguments.Any(a => UnsupportedTemplateArgument(
-                    specialization, a, typeMaps)) ||
+                specialization.Arguments.Any(a => specialization.UnsupportedTemplateArgument(a, typeMaps)) ||
                 container.Namespace == specialization)) ||
                 (!internalOnly && specialization.TemplatedDecl.TemplatedClass.IsIncomplete) ||
                 specialization is ClassTemplatePartialSpecialization;

src/Generator/Generators/CSharp/CSharpSourcesExtensions.cs

@@ -41,6 +41,7 @@ namespace CppSharp.Generators.CSharp
             static bool allPointers(TemplateArgument a) => a.Type.Type?.Desugar().IsAddress() == true;
             var groups = (from @class in specializations
                           let spec = @class.GetParentSpecialization()
+                          orderby spec.IsGenerated descending
                           group @class by spec.Arguments.All(allPointers)
                           into @group
                           select @group).ToList();

src/Generator/Passes/CheckIgnoredDecls.cs

@@ -52,7 +52,9 @@ namespace CppSharp.Passes
                 return false;
 
             TypeMap typeMap;
-            if (!Options.GenerateClassTemplates && !specialization.IsExplicitlyGenerated &&
+            if (!Options.GenerateClassTemplates &&
+                !specialization.IsExplicitlyGenerated &&
+                specialization.GenerationKind != GenerationKind.Internal &&
                 !Context.TypeMaps.FindTypeMap(specialization, out typeMap))
             {
                 specialization.ExplicitlyIgnore();
@@ -578,7 +580,7 @@ namespace CppSharp.Passes
         private void IgnoreUnsupportedTemplates(Class @class)
         {
             if (@class.TemplateParameters.Any(param => param is NonTypeTemplateParameter))
-                foreach (var specialization in @class.Specializations)
+                foreach (var specialization in @class.Specializations.Where(s => s.IsGenerated))
                     specialization.ExplicitlyIgnore();
 
             if (!Options.IsCLIGenerator && !@class.TranslationUnit.IsSystemHeader &&
@@ -589,7 +591,7 @@ namespace CppSharp.Passes
             foreach (var specialization in @class.Specializations)
                 if (specialization.IsExplicitlyGenerated)
                     hasExplicitlyGeneratedSpecializations = true;
-                else
+                else if (specialization.GenerationKind != GenerationKind.Internal)
                     specialization.ExplicitlyIgnore();
 
             if (!hasExplicitlyGeneratedSpecializations)

src/Generator/Passes/GenerateSymbolsPass.cs

@@ -83,6 +83,16 @@ namespace CppSharp.Passes
             }
         }
 
+        public override bool VisitClassTemplateSpecializationDecl(ClassTemplateSpecialization specialization)
+        {
+            if (!specialization.IsGenerated ||
+                specialization.Arguments.Any(
+                    a => specialization.UnsupportedTemplateArgument(a, Context.TypeMaps)))
+                return false;
+
+            return base.VisitClassTemplateSpecializationDecl(specialization);
+        }
+
         public override bool VisitClassDecl(Class @class)
         {
             if (!base.VisitClassDecl(@class))

src/Generator/Passes/IgnoreSystemDeclarationsPass.cs

@@ -35,7 +35,7 @@ namespace CppSharp.Passes
             if (!@class.IsDependent || @class.Specializations.Count == 0)
                 return false;
 
-            foreach (var specialization in @class.Specializations)
+            foreach (var specialization in @class.Specializations.Where(s => s.IsGenerated))
                 specialization.ExplicitlyIgnore();
 
             // we only need a few members for marshalling so strip the rest
@@ -46,11 +46,14 @@ namespace CppSharp.Passes
                 case "char_traits":
                     @class.GenerationKind = GenerationKind.Generate;
                     foreach (var specialization in from s in @class.Specializations
+                                                   where !s.Arguments.Any(a =>
+                                                       s.UnsupportedTemplateArgument(a, Context.TypeMaps))
                                                    let arg = s.Arguments[0].Type.Type.Desugar()
                                                    where arg.IsPrimitiveType(PrimitiveType.Char)
                                                    select s)
                     {
                         specialization.GenerationKind = GenerationKind.Generate;
+                        InternalizeSpecializationsInFields(specialization);
                     }
                     break;
             }
@@ -100,5 +103,22 @@ namespace CppSharp.Passes
 
             return true;
         }
+
+        private void InternalizeSpecializationsInFields(ClassTemplateSpecialization specialization)
+        {
+            foreach (Field field in specialization.Fields)
+            {
+                ASTUtils.CheckTypeForSpecialization(field.Type, specialization,
+                    specialization =>
+                    {
+                        if (!specialization.IsExplicitlyGenerated &&
+                            specialization.GenerationKind != GenerationKind.Internal)
+                        {
+                            specialization.GenerationKind = GenerationKind.Internal;
+                            InternalizeSpecializationsInFields(specialization);
+                        }
+                    }, Context.TypeMaps, true);
+            }
+        }
     }
 }

src/Generator/Passes/TrimSpecializationsPass.cs

@@ -22,7 +22,7 @@ namespace CppSharp.Passes
 
         public override bool VisitClassDecl(Class @class)
         {
-            if (!base.VisitClassDecl(@class))
+            if (!@class.Ignore && !base.VisitClassDecl(@class))
                 return false;
 
             if (@class.IsTemplate)
@@ -124,7 +124,7 @@ namespace CppSharp.Passes
                 specialization.ExplicitlyIgnore();
 
             foreach (var specialization in template.Specializations.Where(
-                s => !s.IsExplicitlyGenerated && internalSpecializations.Contains(s)))
+                s => !s.IsExplicitlyGenerated && !s.Ignore && internalSpecializations.Contains(s)))
                 specialization.GenerationKind = GenerationKind.Internal;
 
             for (int i = template.Specializations.Count - 1; i >= 0; i--)

tests/NamespacesDerived/NamespacesDerived.Gen.cs

@@ -27,6 +27,11 @@ namespace CppSharp.Tests
             module.Libraries.Add($"{@base}.Native");
             driver.Options.Modules[1].Dependencies.Add(module);
         }
+
+        public override void Preprocess(Driver driver, AST.ASTContext ctx)
+        {
+            ctx.IgnoreClassWithName("Ignored");
+        }
     }
 
     public static class NamespacesDerived

tests/NamespacesDerived/NamespacesDerived.h

@@ -1,6 +1,7 @@
 #include "../Tests.h"
 #include "../NamespacesBase/NamespacesBase.h"
 #include "Independent.h"
+#include <string>
 
 // Namespace clashes with NamespacesBase.OverlappingNamespace
 // Test whether qualified names turn out right.
@@ -86,6 +87,27 @@ class DLL_API DerivedFromSecondaryBaseInDependency : public Derived, public Seco
 {
 };
 
+template<typename T>
+class CustomAllocator
+{
+public:
+    typedef T value_type;
+
+    T* allocate(size_t cnt, const void* = 0)
+    {
+        return 0;
+    }
+    void deallocate(T* p, size_t cnt)
+    {
+    }
+};
+
+class DLL_API Ignored
+{
+private:
+    std::basic_string<char, std::char_traits<char>, CustomAllocator<char>> f;
+};
+
 DLL_API bool operator<<(const Base& b, const char* str);
 
 namespace NamespacesBase