Handled struct members which are pointers to data with the type of the containing struct. ie struct foo { foo* Next; }

meta/foldhaus_meta.cpp

@@ -1,3 +1,15 @@
+//
+// Usage
+//
+// GSMetaTag(<tag name>) to give commands to the meta layer
+//
+// Tag Values
+// 
+// breakpoint 
+//   will cause the meta layer to break in the debugger when it reaches
+//   that point in processing the file
+//   TODO: specify which stage you want it to break at
+
 #include <windows.h>
 #include <stdio.h>
 
@@ -354,7 +366,15 @@ ParseMetaTag(token_iter* Iter, gs_bucket<token*>* TagList)
         if (Iter->TokenAt->Type == Token_Identifier)
         {
             TagList->PushElementOnBucket(Iter->TokenAt);
+            if (StringsEqual(Iter->TokenAt->Text, MakeStringLiteral("breakpoint")))
+            {
+                // NOTE(Peter): This is not a temporary breakpoint. It is 
+                // used to be able to break the meta program at specific points
+                // throughout execution
+                __debugbreak();
+            }
             NextToken(Iter);
+            
             if (TokenAtEquals(Iter, ")") &&
                 TokenAtEquals(Iter, ";"))
             {
@@ -790,7 +810,7 @@ ParseStruct(token_iter* Iter, s32* StructTypeIndexOut, gs_bucket<token*>* TagLis
             if (TokenAtEquals(Iter, ";"))
             {
                 Result = true;
-                *StructTypeIndexOut = TypeTable->Types.PushElementOnBucket(StructDecl);
+                *StructTypeIndexOut = PushTypeDefOnTypeTable(StructDecl, TypeTable);
             }
         }
     }
@@ -872,7 +892,7 @@ ParseFunctionDeclaration (token_iter* Iter, token* Identifier, gs_bucket<token*>
                 if (TokenAtEquals(Iter, ";"))
                 {
                     Result = true;
-                    TypeTable->Types.PushElementOnBucket(FunctionPtr);
+                    PushTypeDefOnTypeTable(FunctionPtr, TypeTable);
                 }
             }
         }
@@ -934,17 +954,7 @@ ParseTypedef(token_iter* Iter, gs_bucket<token*>* TagList, type_table* TypeTable
                 NextToken(Iter);
                 
                 Result = true;
-                
+                PushTypeDefOnTypeTable(NewType, TypeTable);
-                s32 ExistingUndeclaredTypeIndex = GetIndexOfType(NewType.Identifier, *TypeTable);
-                if (ExistingUndeclaredTypeIndex < 0)
-                {
-                    TypeTable->Types.PushElementOnBucket(NewType);
-                }
-                else
-                {
-                    type_definition* ExistingTypeDef = TypeTable->Types.GetElementAtIndex(ExistingUndeclaredTypeIndex);
-                    *ExistingTypeDef = NewType;
-                }
             }
         }
         else
@@ -1190,11 +1200,11 @@ int main(int ArgCount, char** ArgV)
         type_definition* TypeDef = TypeTable.Types.GetElementAtIndex(i);
         if (TypeDef->Type == TypeDef_Struct)
         {
-            FixUpStructSize(TypeDef, TypeTable);
+            FixUpStructSize(i, TypeTable);
         }
         else if (TypeDef->Type == TypeDef_Union)
         {
-            FixUpUnionSize(TypeDef, TypeTable);
+            FixUpUnionSize(i, TypeTable);
         }
     }
     

meta/foldhaus_meta_type_table.h

@@ -78,6 +78,19 @@ struct type_table
     gs_bucket<type_definition> Types;
 };
 
+internal void
+MetaTagBreakpoint(gs_bucket<meta_tag> Tags)
+{
+    for (u32 i = 0; i < Tags.Used; i++)
+    {
+        meta_tag* Tag = Tags.GetElementAtIndex(i);
+        if (StringsEqual(Tag->Identifier, MakeStringLiteral("breakpoint")))
+        {
+            __debugbreak();
+        }
+    }
+}
+
 internal void
 CopyMetaTagsAndClear(gs_bucket<token*>* Source, gs_bucket<meta_tag>* Dest)
 {
@@ -91,35 +104,6 @@ CopyMetaTagsAndClear(gs_bucket<token*>* Source, gs_bucket<meta_tag>* Dest)
     Source->Used = 0;
 }
 
-internal type_definition*
-PushStructOnTypeTable(string Identifier, type_definition_type DeclType, gs_bucket<token*>* TagList, type_table* TypeTable)
-{
-    Assert(DeclType == TypeDef_Struct || DeclType == TypeDef_Union);
-    
-    type_definition* Result = TypeTable->Types.TakeElement();
-    *Result = {0};
-    
-    Result->Type = DeclType;
-    Result->Identifier = Identifier;
-    CopyMetaTagsAndClear(TagList, &Result->MetaTags);
-    return Result;
-}
-
-internal s32
-PushTypeDefOnTypeTable(type_definition TypeDef, type_table* TypeTable)
-{
-    s32 Index = -1;
-    if (TypeDef.Type != TypeDef_BasicType)
-    {
-        printf("Invalid TypeDef: %.*s\n", StringExpand(TypeDef.Identifier));
-    } 
-    else
-    {
-        Index = TypeTable->Types.PushElementOnBucket(TypeDef);
-    }
-    return Index;
-}
-
 internal s32
 PushUndeclaredType (string Identifier, type_table* TypeTable)
 {
@@ -146,6 +130,26 @@ GetIndexOfType (string Identifier, type_table TypeTable)
     return Result;
 }
 
+internal s32
+PushTypeDefOnTypeTable(type_definition TypeDef, type_table* TypeTable)
+{
+    s32 Index = -1;
+    
+    s32 ExistingUndeclaredTypeIndex = GetIndexOfType(TypeDef.Identifier, *TypeTable);
+    if (ExistingUndeclaredTypeIndex < 0)
+    {
+        Index = TypeTable->Types.PushElementOnBucket(TypeDef);
+    }
+    else
+    {
+        Index = ExistingUndeclaredTypeIndex;
+        type_definition* ExistingTypeDef = TypeTable->Types.GetElementAtIndex(ExistingUndeclaredTypeIndex);
+        *ExistingTypeDef = TypeDef;
+    }
+    
+    return Index;
+}
+
 internal s32
 GetSizeOfType (s32 TypeIndex, type_table TypeTable)
 {
@@ -241,8 +245,8 @@ FindIndexOfMatchingType (type_definition Match, type_table TypeTable)
     return Result;
 }
 
-internal void FixUpStructSize (type_definition* Struct, type_table TypeTable);
+internal void FixUpStructSize (s32 StructIndex, type_table TypeTable);
-internal void FixUpUnionSize (type_definition* Union, type_table TypeTable);
+internal void FixUpUnionSize (s32 UnionIndex, type_table TypeTable);
 
 internal void
 FixupMemberType (variable_decl* Member, type_table TypeTable)
@@ -275,10 +279,13 @@ CalculateStructMemberSize (variable_decl Member, type_definition MemberType)
 }
 
 internal void
-FixUpStructSize (type_definition* Struct, type_table TypeTable)
+FixUpStructSize (s32 StructIndex, type_table TypeTable)
 {
+    type_definition* Struct = TypeTable.Types.GetElementAtIndex(StructIndex);
     Assert(Struct->Type == TypeDef_Struct);
     
+    MetaTagBreakpoint(Struct->MetaTags);
+    
     s32 SizeAcc = 0;
     for (u32 j = 0; j < Struct->Struct.MemberDecls.Used; j++)
     {
@@ -288,15 +295,23 @@ FixUpStructSize (type_definition* Struct, type_table TypeTable)
         if (Member->TypeIndex >= 0)
         {
             type_definition* MemberTypeDef = TypeTable.Types.GetElementAtIndex(Member->TypeIndex);
-            if (MemberTypeDef->Size == 0)
+            
+            // NOTE(Peter): This signals a nested pointer to an address of the
+            // same type as the one we are parsing now. In that case, the size
+            // also hasn't been determined yet, but we know the size of the member
+            // is just a pointer (32 or 64 bits).
+            // For example, this would go into an infinite recursion without the case
+            // of StructIndex != Member->TypeIndex:
+            //     struct foo { foo* Next; }
+            if (MemberTypeDef->Size == 0 && StructIndex != Member->TypeIndex)
             {
                 if (MemberTypeDef->Type == TypeDef_Struct)
                 {
-                    FixUpStructSize(MemberTypeDef, TypeTable);
+                    FixUpStructSize(Member->TypeIndex, TypeTable);
                 }
                 else if (MemberTypeDef->Type == TypeDef_Union)
                 {
-                    FixUpUnionSize(MemberTypeDef, TypeTable);
+                    FixUpUnionSize(Member->TypeIndex, TypeTable);
                 }
                 else 
                 { 
@@ -305,7 +320,7 @@ FixUpStructSize (type_definition* Struct, type_table TypeTable)
 #if 0
                     InvalidCodePath;
 #else
-                    printf("Error: TypeDef Size = 0. %.*s\n", StringExpand(MemberTypeDef->Identifier));
+                    printf("Struct Error: TypeDef Size = 0. %.*s\n", StringExpand(MemberTypeDef->Identifier));
 #endif
                 }
             }
@@ -327,14 +342,15 @@ FixUpStructSize (type_definition* Struct, type_table TypeTable)
 #else
     if (Struct->Size == 0)
     {
-        printf("Error: Struct Size = 0. %.*s\n", StringExpand(Struct->Identifier));
+        printf("Struct Error: Struct Size = 0. %.*s\n", StringExpand(Struct->Identifier));
     }
 #endif
 }
 
 internal void
-FixUpUnionSize (type_definition* Union, type_table TypeTable)
+FixUpUnionSize (s32 UnionIndex, type_table TypeTable)
 {
+    type_definition* Union = TypeTable.Types.GetElementAtIndex(UnionIndex);
     Assert(Union->Type == TypeDef_Union);
     
     s32 BiggestMemberSize = 0;
@@ -350,11 +366,11 @@ FixUpUnionSize (type_definition* Union, type_table TypeTable)
             {
                 if (MemberTypeDef->Type == TypeDef_Struct)
                 {
-                    FixUpStructSize(MemberTypeDef, TypeTable);
+                    FixUpStructSize(Member->TypeIndex, TypeTable);
                 }
                 else if(MemberTypeDef->Type == TypeDef_Union)
                 {
-                    FixUpUnionSize(MemberTypeDef, TypeTable);
+                    FixUpUnionSize(Member->TypeIndex, TypeTable);
                 }
                 else 
                 { 
@@ -363,7 +379,7 @@ FixUpUnionSize (type_definition* Union, type_table TypeTable)
 #if 0
                     InvalidCodePath;
 #else
-                    printf("Error: TypeDef Size = 0. %.*s\n", StringExpand(MemberTypeDef->Identifier));
+                    printf("Union Error: TypeDef Size = 0. %.*s\n", StringExpand(MemberTypeDef->Identifier));
 #endif
                 }
             }
@@ -385,7 +401,7 @@ FixUpUnionSize (type_definition* Union, type_table TypeTable)
 #else
     if (Union->Size == 0)
     {
-        printf("Error: Struct Size = 0. %.*s\n", StringExpand(Union->Identifier));
+        printf("Union Error: Struct Size = 0. %.*s\n", StringExpand(Union->Identifier));
     }
 #endif
 }