structure for system calls

generators/wraith.lex

@@ -40,6 +40,7 @@
 ";"                         return SEMICOLON;
 ":"                         return COLON;
 "?"                         return QUESTION;
+"@"                         return AT;
 "("                         return LEFT_PAREN;
 ")"                         return RIGHT_PAREN;
 "["                         return LEFT_BRACKET;

generators/wraith.y

@@ -54,6 +54,7 @@ extern FILE *yyin;
 %token SEMICOLON
 %token COLON
 %token QUESTION
+%token AT
 %token LEFT_PAREN
 %token RIGHT_PAREN
 %token LEFT_BRACE
@@ -141,6 +142,11 @@ AccessExpression        : Identifier POINT AccessExpression
                             $$ = $1;
                         }
 
+SystemCallExpression    : AT Identifier
+                        {
+                            $$ = $2;
+                        }
+
 Number                  : NUMBER
                         {
                             $$ = MakeNumberNode(yytext);
@@ -234,6 +240,10 @@ FunctionCallExpression  : AccessExpression LEFT_PAREN Arguments RIGHT_PAREN
                         {
                             $$ = MakeFunctionCallExpressionNode($1, $3);
                         }
+                        | SystemCallExpression LEFT_PAREN Arguments RIGHT_PAREN
+                        {
+                            $$ = MakeSystemCallExpressionNode($1, $3);
+                        }
 
 PartialStatement        : FunctionCallExpression
                         | AssignmentStatement

generic.w

@@ -13,6 +13,8 @@ struct Program {
     static Main(): int {
         x: int = 4;
         y: int = Foo.Func(x);
+        addr: uint = @malloc(y);
+        @free(addr);
         return x;
     }
 }

src/ast.c

@@ -67,6 +67,8 @@ const char *SyntaxKindString(SyntaxKind syntaxKind)
         return "StringLiteral";
     case StructDeclaration:
         return "StructDeclaration";
+    case SystemCall:
+        return "SystemCall";
     case Type:
         return "Type";
     case UnaryExpression:
@@ -426,6 +428,17 @@ Node *MakeFunctionCallExpressionNode(
     return node;
 }
 
+Node *MakeSystemCallExpressionNode(
+    Node *identifierNode,
+    Node *argumentSequenceNode)
+{
+    Node *node = (Node *)malloc(sizeof(Node));
+    node->syntaxKind = SystemCall;
+    node->systemCall.identifier = identifierNode;
+    node->systemCall.argumentSequence = argumentSequenceNode;
+    return node;
+}
+
 Node *MakeAccessExpressionNode(Node *accessee, Node *accessor)
 {
     Node *node = (Node *)malloc(sizeof(Node));

src/ast.h

@@ -44,6 +44,7 @@ typedef enum
     StaticModifier,
     StringLiteral,
     StructDeclaration,
+    SystemCall,
     Type,
     UnaryExpression
 } SyntaxKind;
@@ -287,6 +288,12 @@ struct Node
             Node *declarationSequence;
         } structDeclaration;
 
+        struct
+        {
+            Node *identifier;
+            Node *argumentSequence;
+        } systemCall;
+
         struct
         {
             Node *typeNode;
@@ -349,6 +356,9 @@ Node *MakeEmptyFunctionArgumentSequenceNode();
 Node *MakeFunctionCallExpressionNode(
     Node *identifierNode,
     Node *argumentSequenceNode);
+Node *MakeSystemCallExpressionNode(
+    Node *identifierNode,
+    Node *argumentSequenceNode);
 Node *MakeAccessExpressionNode(Node *accessee, Node *accessor);
 Node *MakeAllocNode(Node *typeNode);
 Node *MakeIfNode(Node *expressionNode, Node *statementSequenceNode);

src/codegen.c

@@ -112,6 +112,16 @@ typedef struct StructTypeDeclaration
 StructTypeDeclaration *structTypeDeclarations;
 uint32_t structTypeDeclarationCount;
 
+typedef struct SystemFunction
+{
+    char *name;
+    LLVMTypeRef functionType;
+    LLVMValueRef function;
+} SystemFunction;
+
+SystemFunction *systemFunctions;
+uint32_t systemFunctionCount;
+
 /* FUNCTION FORWARD DECLARATIONS */
 static LLVMBasicBlockRef CompileStatement(
     LLVMModuleRef module,
@@ -262,6 +272,36 @@ static LLVMTypeRef ResolveType(TypeTag *typeTag)
     }
 }
 
+static void AddSystemFunction(
+    char *name,
+    LLVMTypeRef functionType,
+    LLVMValueRef function)
+{
+    systemFunctions = realloc(
+        systemFunctions,
+        sizeof(SystemFunction) * (systemFunctionCount + 1));
+    systemFunctions[systemFunctionCount].name = strdup(name);
+    systemFunctions[systemFunctionCount].functionType = functionType;
+    systemFunctions[systemFunctionCount].function = function;
+    systemFunctionCount += 1;
+}
+
+static SystemFunction *LookupSystemFunction(char *name)
+{
+    uint32_t i;
+
+    for (i = 0; i < systemFunctionCount; i += 1)
+    {
+        if (strcmp(name, systemFunctions[i].name) == 0)
+        {
+            return &systemFunctions[i];
+        }
+    }
+
+    fprintf(stderr, "%s %s %s", "System function", name, "not found!");
+    return NULL;
+}
+
 static void AddLocalVariable(
     Scope *scope,
     LLVMValueRef pointer, /* can be NULL */
@@ -1133,6 +1173,51 @@ static LLVMValueRef CompileFunctionCallExpression(
     return LLVMBuildCall(builder, function, args, argumentCount, returnName);
 }
 
+static LLVMValueRef CompileSystemCallExpression(
+    LLVMModuleRef module,
+    LLVMBuilderRef builder,
+    Node *systemCallExpression)
+{
+    uint32_t i;
+    uint32_t argumentCount = systemCallExpression->systemCall.argumentSequence
+                                 ->functionArgumentSequence.count;
+    LLVMValueRef args[argumentCount];
+    char *returnName = "";
+
+    for (i = 0; i < systemCallExpression->systemCall.argumentSequence
+                        ->functionArgumentSequence.count;
+         i += 1)
+    {
+        args[i] = CompileExpression(
+            module,
+            builder,
+            systemCallExpression->systemCall.argumentSequence
+                ->functionArgumentSequence.sequence[i]);
+    }
+
+    SystemFunction *systemFunction = LookupSystemFunction(
+        systemCallExpression->systemCall.identifier->identifier.name);
+
+    if (systemFunction == NULL)
+    {
+        fprintf(stderr, "System function not found!");
+        return NULL;
+    }
+
+    if (LLVMGetTypeKind(LLVMGetReturnType(systemFunction->functionType)) !=
+        LLVMVoidTypeKind)
+    {
+        returnName = "callReturn";
+    }
+
+    return LLVMBuildCall(
+        builder,
+        systemFunction->function,
+        args,
+        argumentCount,
+        returnName);
+}
+
 static LLVMValueRef CompileAccessExpressionForStore(
     LLVMBuilderRef builder,
     Node *accessExpression)
@@ -1196,6 +1281,9 @@ static LLVMValueRef CompileExpression(
 
     case StringLiteral:
         return CompileString(builder, expression);
+
+    case SystemCall:
+        return CompileSystemCallExpression(module, builder, expression);
     }
 
     fprintf(stderr, "Unknown expression kind!\n");
@@ -1516,6 +1604,10 @@ static LLVMBasicBlockRef CompileStatement(
 
     case ReturnVoid:
         return CompileReturnVoid(builder, function);
+
+    case SystemCall:
+        CompileSystemCallExpression(module, builder, statement);
+        return LLVMGetLastBasicBlock(function);
     }
 
     fprintf(stderr, "Unknown statement kind!\n");
@@ -1812,6 +1904,24 @@ static void RegisterLibraryFunctions(
         LLVMInt8Type(),
         1,
         "PrintLine");
+
+    LLVMTypeRef mallocArg = LLVMInt64Type();
+    LLVMTypeRef mallocFunctionType =
+        LLVMFunctionType(LLVMInt64Type(), &mallocArg, 1, 0);
+    LLVMValueRef mallocFunction =
+        LLVMAddFunction(module, "malloc", mallocFunctionType);
+    LLVMSetLinkage(mallocFunction, LLVMExternalLinkage);
+
+    AddSystemFunction("malloc", mallocFunctionType, mallocFunction);
+
+    LLVMTypeRef freeArg = LLVMInt64Type();
+    LLVMTypeRef freeFunctionType =
+        LLVMFunctionType(LLVMVoidType(), &freeArg, 1, 0);
+    LLVMValueRef freeFunction =
+        LLVMAddFunction(module, "free", freeFunctionType);
+    LLVMSetLinkage(freeFunction, LLVMExternalLinkage);
+
+    AddSystemFunction("free", freeFunctionType, freeFunction);
 }
 
 int Codegen(Node *node, uint32_t optimizationLevel)
@@ -1821,6 +1931,9 @@ int Codegen(Node *node, uint32_t optimizationLevel)
     structTypeDeclarations = NULL;
     structTypeDeclarationCount = 0;
 
+    systemFunctions = NULL;
+    systemFunctionCount = 0;
+
     LLVMModuleRef module = LLVMModuleCreateWithName("my_module");
     LLVMContextRef context = LLVMGetGlobalContext();