add: parse labels and syscalls

4 files changed, 82 insertions, 9 deletions

diff --git a/src/main.c b/src/main.c
index 2f5f4d1..a44350e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -62,14 +62,27 @@ int main(int argc, char** argv)
 		for (size_t s = 0; s < proc.body_count; s += 1)
 		{
 			struct Statement statement = proc.body[s];
-			if (statement.kind == STATEMENT_ASSIGN)
+			switch (statement.kind)
 			{
-				struct AssignStatement assign = statement.assign;
-				printf("  %s%.*s %.*s %.*s\n",
-					assign.target_deref ? "^" : "",
-					(int)assign.target.length, assign.target.start,
-					(int)assign.op.length, assign.op.start,
-					(int)assign.value.length, assign.value.start);
+				case STATEMENT_ASSIGN:
+				{
+					struct AssignStatement assign = statement.assign;
+					printf("  %s%.*s %.*s %.*s\n",
+						assign.target_deref ? "^" : "",
+						(int)assign.target.length, assign.target.start,
+						(int)assign.op.length, assign.op.start,
+						(int)assign.value.length, assign.value.start);
+					break;
+				}
+				case STATEMENT_LABEL:
+					printf("  %.*s:\n", (int)statement.label.name.length, statement.label.name.start);
+					break;
+				case STATEMENT_GOTO:
+					printf("  goto %.*s\n", (int)statement.jump.label.length, statement.jump.label.start);
+					break;
+				case STATEMENT_SYSCALL:
+					printf("  syscall\n");
+					break;
 			}
 		}
 	}
diff --git a/src/parser/ast.h b/src/parser/ast.h
index 83483e9..4604e1a 100644
--- a/src/parser/ast.h
+++ b/src/parser/ast.h
@@ -26,6 +26,9 @@ struct Param
 enum StatementKind
 {
 	STATEMENT_ASSIGN,
+	STATEMENT_LABEL,
+	STATEMENT_GOTO,
+	STATEMENT_SYSCALL,
 };
 
 struct AssignStatement
@@ -36,12 +39,24 @@ struct AssignStatement
 	struct Token value;
 };
 
+struct LabelStatement
+{
+	struct Token name;
+};
+
+struct GotoStatement
+{
+	struct Token label;
+};
+
 struct Statement
 {
 	enum StatementKind kind;
 	union
 	{
 		struct AssignStatement assign;
+		struct LabelStatement label;
+		struct GotoStatement jump;
 	};
 };
 
diff --git a/src/parser/parser.c b/src/parser/parser.c
index d86502f..a125b7d 100644
--- a/src/parser/parser.c
+++ b/src/parser/parser.c
@@ -138,11 +138,34 @@ static bool parse_value(struct Parser* parser, struct Token* out)
 
 static bool parse_statement(struct Parser* parser, struct Statement* out)
 {
+	if (match_token(parser, TOKEN_SYSCALL))
+	{
+		out->kind = STATEMENT_SYSCALL;
+		return true;
+	}
+
+	if (match_token(parser, TOKEN_GOTO))
+	{
+		if (!consume(parser, TOKEN_IDENTIFIER, "expected label after 'goto'"))
+			return false;
+
+		out->kind = STATEMENT_GOTO;
+		out->jump.label = parser->previous;
+		return true;
+	}
+
 	bool deref = match_token(parser, TOKEN_CARET);
 
 	if (!consume(parser, TOKEN_IDENTIFIER, "expected a statement"))
 		return false;
-	struct Token target = parser->previous;
+	struct Token name = parser->previous;
+
+	if (!deref && match_token(parser, TOKEN_COLON))
+	{
+		out->kind = STATEMENT_LABEL;
+		out->label.name = name;
+		return true;
+	}
 
 	if (!is_assign_op(parser->current.type))
 	{
@@ -152,7 +175,7 @@ static bool parse_statement(struct Parser* parser, struct Statement* out)
 
 	struct AssignStatement assign;
 	assign.target_deref = deref;
-	assign.target = target;
+	assign.target = name;
 	advance_parser(parser);
 	assign.op = parser->previous;
 
diff --git a/tests/parser_test.c b/tests/parser_test.c
index 85626a0..ea18add 100644
--- a/tests/parser_test.c
+++ b/tests/parser_test.c
@@ -83,6 +83,27 @@ static void test_parse_proc_body(struct TestContext* context)
 	free_program(&program);
 }
 
+static void test_parse_simple_statements(struct TestContext* context)
+{
+	struct Lexer lexer = create_lexer("proc main\n{\nloop:\nsyscall\ngoto loop\n}\n");
+	struct Program program;
+
+	check(context, parse_program(&lexer, &program));
+	check(context, program.procs[0].body_count == 3);
+
+	struct Statement label = program.procs[0].body[0];
+	check(context, label.kind == STATEMENT_LABEL);
+	check(context, text_is(label.label.name, "loop"));
+
+	check(context, program.procs[0].body[1].kind == STATEMENT_SYSCALL);
+
+	struct Statement jump = program.procs[0].body[2];
+	check(context, jump.kind == STATEMENT_GOTO);
+	check(context, text_is(jump.jump.label, "loop"));
+
+	free_program(&program);
+}
+
 static void test_parse_errors(struct TestContext* context)
 {
 	struct Program program;
@@ -106,5 +127,6 @@ void run_parser_tests(struct TestContext* context)
 	test_parse_data(context);
 	test_parse_proc_params(context);
 	test_parse_proc_body(context);
+	test_parse_simple_statements(context);
 	test_parse_errors(context);
 }