Introduce null keyword

src/ast/ast.c

@@ -92,6 +92,7 @@ void generic_visitor(AST **nptr, AST *stmt, AST *stmtPrev, AST *chu, AST *tlc, v
 			generic_visitor(&n->stmtJump.condition, stmt, stmtPrev, chu, tlc, ud, preHandler, postHandler);
 		}
 	} else if(n->nodeKind == AST_STMT_LABEL) {
+	} else if(n->nodeKind == AST_EXPR_NULL) {
 	} else {
 		stahp_node(n, "generic_visitor: unhandled %s", AST_KIND_STR[n->nodeKind]);
 	}

src/ast/ast.h

@@ -44,7 +44,8 @@
 	K(AST_EXPR_DOT)				\
 	K(AST_EXPR_EXT_SIZEOF)		\
 	K(AST_STMT_JUMP)			\
-	K(AST_STMT_LABEL)			
+	K(AST_STMT_LABEL)			\
+	K(AST_EXPR_NULL)			
 
 typedef enum ENUMPAK { AST_KINDS(GEN_ENUM) } ASTKind;
 extern const char *AST_KIND_STR[];
@@ -331,6 +332,10 @@ typedef struct {
 	char *name;
 } ASTStmtLabel;
 
+typedef struct {
+	ASTExpr;
+} ASTExprNull;
+
 typedef union AST {
 	ASTBase;
 	
@@ -362,6 +367,7 @@ typedef union AST {
 	ASTExprExtSizeOf exprExtSizeOf;
 	ASTStmtJump stmtJump;
 	ASTStmtLabel stmtLabel;
+	ASTExprNull exprNull;
 } AST;
 
 #pragma pack(pop)

src/lexer.c

@@ -27,7 +27,9 @@ char *TOKEN_NAMES[] = {
 	"'break'",
 	"','",
 	"'&'",
+	"'&&'",
 	"'|'",
+	"'||'",
 	"'^'",
 	"'~'",
 	"'=='",
@@ -50,6 +52,7 @@ char *TOKEN_NAMES[] = {
 	"'as'",
 	"'use'",
 	"'else'",
+	"'null'",
 };
 
 static int isAlpha(int c) {
@@ -309,6 +312,10 @@ Token nct_tokenize(FILE *f) {
 			free(content);
 			tok.type = TOKEN_ELSE;
 			return tok;
+		} else if(!strcmp(content, "null")) {
+			free(content);
+			tok.type = TOKEN_NULL;
+			return tok;
 		}
 		
 		tok.type = TOKEN_IDENTIFIER;

src/lexer.h

@@ -52,6 +52,7 @@ typedef enum {
 	TOKEN_AS,
 	TOKEN_USE,
 	TOKEN_ELSE,
+	TOKEN_NULL,
 } TokenKind;
 
 typedef struct Token {

src/parse.c

@@ -269,6 +269,12 @@ AST *nct_parse_expression(Parser *P, int lOP) {
 				
 				e = (AST*) exprvar(P, vte);
 			}
+		} else if(maybe(P, TOKEN_NULL)) {
+			ASTExprNull *ret = alloc_node(P, sizeof(*ret));
+			ret->nodeKind = AST_EXPR_NULL;
+			ret->type = type_pointer_wrap(type_u(8));
+			
+			e = (AST*) ret;
 		} else if(peek(P, 0).type == TOKEN_STRING) {
 			ASTExprStringLiteral *ret = alloc_node(P, sizeof(*ret));
 			ret->nodeKind = AST_EXPR_STRING_LITERAL;

src/x86/normalize.c

@@ -596,7 +596,16 @@ static void denoop_visitor(AST **nptr, AST *stmt, AST *stmtPrev, AST *chunk, AST
 	
 	bool *success = &state->success;
 	
-	if(n->nodeKind == AST_EXPR_UNARY_OP && n->exprUnOp.operator == UNOP_REF && n->exprUnOp.operand->nodeKind == AST_EXPR_UNARY_OP && n->exprUnOp.operand->exprUnOp.operator == UNOP_DEREF) {
+	if(n->nodeKind == AST_EXPR_NULL) {
+		// Turn `null` into integer
+		
+		ASTExprPrimitive *prim = calloc(1, sizeof(*prim));
+		prim->nodeKind = AST_EXPR_PRIMITIVE;
+		prim->type = n->expression.type;
+		prim->val = ntc_get_int_default("null", 0);
+		
+		*nptr = (AST*) prim;
+	} else if(n->nodeKind == AST_EXPR_UNARY_OP && n->exprUnOp.operator == UNOP_REF && n->exprUnOp.operand->nodeKind == AST_EXPR_UNARY_OP && n->exprUnOp.operand->exprUnOp.operator == UNOP_DEREF) {
 		// Turn `&*a` into `a`
 		
 		// Artificially change type of casted expression to keep types valid for subsequent passes