Implement enums and the foundation of a type alias system

include/Data.h

@@ -22,9 +22,11 @@ extern_ struct SymbolTableEntry* Params, * ParamsEnd;
 extern_ struct SymbolTableEntry* Structs, * StructsEnd;
 
 extern_ struct SymbolTableEntry* CompositeMembers, * CompositeMembersEnd;
+extern_ struct SymbolTableEntry* EnumMembers, * EnumMembersEnd;
 
 extern_ struct SymbolTableEntry* Unions, * UnionsEnd;
 extern_ struct SymbolTableEntry* Enums, * EnumsEnd;
+extern_ struct SymbolTableEntry* Types, * TypesEnd;
 
 extern_ bool OptDumpTree;
 extern_ bool OptKeepAssembly;

include/Defs.h

@@ -97,7 +97,9 @@ enum TokenTypes {
     KW_FOR,
     KW_RETURN,
     KW_STRUCT,
-    KW_UNION
+    KW_UNION,
+    KW_ENUM,
+    KW_ALIAS
 };
 
 /*
@@ -222,7 +224,9 @@ enum StorageScope {
     SC_STRUCT,      // Struct Definitions
     SC_UNION,       // Union Definitions
     SC_ENUM,        // Enum Definitions
-    SC_MEMBER,      // The members of Structs or Enums
+    SC_ENUMENTRY,   // Enum Entry Names
+    SC_ALIAS,       // Typedef aliases
+    SC_MEMBER,      // The members of Structs or Unions
     //SC_CLASS,       // Class-local definitions
     //SC_STATIC,      // Static storage definitions
     SC_PARAM,       // Function parameters
@@ -249,6 +253,7 @@ enum DataTypes {
 
     DAT_STRUCT = 80,     // Struct Data
     DAT_UNION,           // Union Data
+    DAT_ENUM = -1,            // Enum Data
 };
 
 /*
@@ -260,8 +265,8 @@ enum StructureType {
     ST_VAR,         // This is variable
     ST_FUNC,        // This is a function
     ST_ARR,         // This is an array
-    ST_RUCT         // This is a struct
-    // This is an enum
+    ST_RUCT,        // This is a struct
+    ST_ENUM,        // This is an enum
     // This is a typedef
 };
 
@@ -352,6 +357,8 @@ struct ASTNode* ParseCompound();
 
 struct SymbolTableEntry* BeginCompositeDeclaration(int Type);
 
+void BeginEnumDeclaration();
+
 struct ASTNode* GetExpressionList();
 
 struct ASTNode* CallFunction();
@@ -389,6 +396,10 @@ struct SymbolTableEntry* FindGlobal(char* Symbol);
 
 struct SymbolTableEntry* FindStruct(char* Symbol);
 
+struct SymbolTableEntry* FindEnum(char* Symbol);
+
+struct SymbolTableEntry* FindEnumMember(char* Symbol);
+
 struct SymbolTableEntry* FindUnion(char* Symbol);
 
 struct SymbolTableEntry* FindMember(char* Symbol);

src/Lexer.c

@@ -283,6 +283,11 @@ static int ReadKeyword(char* Str) {
                 return KW_FUNC;
             break;
 
+        case 'a':
+            if (!strcmp(Str, "alias"))
+                return KW_ALIAS;
+            break;
+
         case 'c':
             if (!strcmp(Str, "char"))
                 return TY_CHAR;
@@ -291,6 +296,8 @@ static int ReadKeyword(char* Str) {
         case 'e':
             if (!strcmp(Str, "else"))
                 return KW_ELSE;
+            if (!strcmp(Str, "enum"))
+                return KW_ENUM;
 
             break;
 

src/Main.c

@@ -89,6 +89,8 @@ char* ScopeNames[] = {
         "STRUCT",
         "UNION",
         "ENUM",
+        "ENUM_ENTRY",
+        "ALIAS",
         "MEMBER",
         "PARAMETER",
         "LOCAL"

src/Parser.c

@@ -534,7 +534,7 @@ void ParseGlobals() {
 
         // Structs are parsed fully in ParseOptionalPointer
         // TODO: FIX THAT!!
-        if ((Type == DAT_STRUCT || Type == DAT_UNION) && CurrentToken.type == LI_SEMIC) {
+        if ((Type == DAT_STRUCT || Type == DAT_UNION || Type == DAT_ENUM) && CurrentToken.type == LI_SEMIC) {
             Tokenise();
             continue;
         }

src/Pointers.c

@@ -96,6 +96,12 @@ int ParseOptionalPointer(struct SymbolTableEntry** Composite) {
             Type = DAT_STRUCT;
             *Composite = BeginCompositeDeclaration(Type);
             break;
+        case KW_ENUM:
+            Type = RET_INT;
+            BeginEnumDeclaration();
+            if (CurrentToken.type == LI_SEMIC)
+                Type = DAT_ENUM;
+            break;
         case KW_UNION:
             Type = DAT_UNION;
             *Composite = BeginCompositeDeclaration(Type);

src/Statements.c

@@ -94,7 +94,7 @@ struct SymbolTableEntry* BeginCompositeDeclaration(int Type) {
     if (Composite)
         DieMessage("Redefinition of composite", CurrentIdentifier);
 
-    Composite = AddSymbol(CurrentIdentifier, Type, 0, Type == DAT_STRUCT ? SC_STRUCT : SC_UNION, 0, 0, NULL);
+    Composite = AddSymbol(CurrentIdentifier, Type, ST_RUCT, Type == DAT_STRUCT ? SC_STRUCT : SC_UNION, 0, 0, NULL);
     Tokenise();
     printf("Reading a composite declaration.. Type is %s\n", Type == DAT_STRUCT ? "struct" : "union");
     ReadDeclarationList(NULL, SC_MEMBER, LI_RBRAC);
@@ -123,6 +123,69 @@ struct SymbolTableEntry* BeginCompositeDeclaration(int Type) {
     return Composite;
 }
 
+void BeginEnumDeclaration() {
+    struct SymbolTableEntry* Type = NULL;
+    char* Name;
+    int Value = 0;
+
+    Tokenise();
+
+    // enum name
+    if (CurrentToken.type == TY_IDENTIFIER) {
+        Type = FindEnum(CurrentIdentifier);
+        Name = strdup(CurrentIdentifier);
+        Tokenise();
+    }
+
+    // enum name {? if not, enum name var.
+    if (CurrentToken.type != LI_LBRAC) {
+        if (Type == NULL)
+            DieMessage("Undeclared Enum", Name);
+
+        return;
+    }
+
+    // Skip the { that we have
+    Tokenise();
+
+    if (Type != NULL)
+        DieMessage("Attempting to redefine enum", Type->Name);
+    else
+        Type = AddSymbol(Name, DAT_ENUM, ST_ENUM, SC_ENUM, 0, 0, NULL);
+
+    while (1) {
+        VerifyToken(TY_IDENTIFIER, "Enum Entry");
+        Name = strdup(CurrentIdentifier);
+
+        Type = FindEnumMember(Name);
+        if (Type != NULL)
+            DieMessage("Attempting to redeclare enum value", Name);
+
+        // Parse equality
+        if (CurrentToken.type == LI_EQUAL) {
+            Tokenise();
+            // Expect a number after the equals
+            if (CurrentToken.type != LI_INT)
+                Die("Expected integer to assign enum value to");
+            Value = CurrentToken.value;
+            Tokenise();
+        }
+
+        Type = AddSymbol(Name, DAT_ENUM, ST_ENUM, SC_ENUMENTRY, Value++, 0, NULL);
+
+        // Break on right brace
+        if (CurrentToken.type == LI_RBRAC)
+            break;
+
+        VerifyToken(LI_COM, "Comma");
+    }
+
+    // Skip right brace
+    Tokenise();
+
+
+}
+
 /*
  * Handles the declaration of a type of a variable.
  *  int newVar;
@@ -502,6 +565,12 @@ struct ASTNode* PostfixStatement() {
     struct ASTNode* Tree;
     struct SymbolTableEntry* Entry;
 
+    // Early exit if we find an enum value
+    if ((Entry = FindEnumMember(CurrentIdentifier)) != NULL) {
+        Tokenise();
+        return ConstructASTLeaf(TERM_INTLITERAL, RET_INT, NULL, Entry->IntValue);
+    }
+
     Tokenise();
 
     if (CurrentToken.type == LI_LPARE)

src/Symbols.c

@@ -120,6 +120,29 @@ struct SymbolTableEntry* FindGlobal(char* Symbol) {
 struct SymbolTableEntry* FindStruct(char* Symbol) {
     return SearchList(Symbol, Structs);
 }
+
+/*
+ * An override for FindSymbol.
+ * Searches only the defined Enums.
+ *  @param Symbol: The string name of the symbol to search for.
+ *  @return a pointer to the node if found, else NULL
+ *
+ */
+struct SymbolTableEntry* FindEnum(char* Symbol) {
+    return SearchList(Symbol, Enums);
+}
+
+/*
+ * An override for FindSymbol.
+ * Searches only the defined enum members.
+ *  @param Symbol: The string name of the symbol to search for.
+ *  @return a pointer to the node if found, else NULL
+ *
+ */
+struct SymbolTableEntry* FindEnumMember(char* Symbol) {
+    return SearchList(Symbol, EnumMembers);
+}
+
 /*
  * An override for FindSymbol.
  * Searches only the defined Unions.
@@ -231,6 +254,12 @@ struct SymbolTableEntry* AddSymbol(char* Name, int Type, int Structure, int Stor
         case SC_UNION:
             AppendSymbol(&Unions, &UnionsEnd, Node);
             break;
+        case SC_ENUM:
+            AppendSymbol(&Enums, &EnumsEnd, Node);
+            break;
+        case SC_ENUMENTRY:
+            AppendSymbol(&EnumMembers, &EnumMembersEnd, Node);
+            break;
         case SC_MEMBER:
             AppendSymbol(&CompositeMembers, &CompositeMembersEnd, Node);
             break;

tests/enum.er

@@ -0,0 +1,18 @@
+int :: printf(char* format);
+
+enum fruit { apple, pear, shallot };
+
+enum basket {
+    abc = 15,
+    def
+};
+
+enum basket thing;
+enum fruit stuff;
+
+int :: main() {
+    int temp;
+    temp = apple + pear + abc;
+    printf("%d\n", temp);
+    return (0);
+}