More exception stuff

src/stack.c

@@ -56,9 +56,8 @@ void lisp_teardown_stack(void) {
 }
 
 static ALWAYS_INLINE StackFrame *PUSH_NEW_FRAME(enum StackFrameKind kind) {
-    if (the_stack.depth == the_stack.max_depth) {
-        // TODO error
-        abort();
+    if (the_stack.depth == LISP_STACK_SOFT_MAX_DEPTH) {
+        lisp_signal(Qexcessive_lisp_nesting_error, Qnil);
     }
     StackFrame *last_refs =
         the_stack.depth ? the_stack.frames[the_stack.depth - 1].last_references
@@ -250,8 +249,7 @@ void push_dynamic_binding(LispVal *name, LispVal *new_value) {
 void set_lexical_variable(LispVal *name, LispVal *value) {
     assert(SYMBOLP(name));
     if (CONST_VALUE_P(name)) {
-        // TODO throw
-        abort();
+        signal_value_constant(name);
     }
     if (DYNAMIC_SYMBOL_P(name)) {
         SET_SYMBOL_VALUE(name, value);
@@ -263,8 +261,7 @@ void set_lexical_variable(LispVal *name, LispVal *value) {
 void new_lexical_variable(LispVal *name, LispVal *value) {
     assert(SYMBOLP(name));
     if (CONST_VALUE_P(name)) {
-        // TODO throw
-        abort();
+        signal_value_constant(name);
     }
     if (DYNAMIC_SYMBOL_P(name)) {
         push_dynamic_binding(name, value);
@@ -366,6 +363,7 @@ noreturn void continue_unwinding(void) {
 }
 
 noreturn void lisp_signal(LispVal *name, LispVal *data) {
+    CHECK_LISTP(data);
     if (NILP(Fcondition_class_p(name))) {
         signal_type_error(name, LIST(Qcondition_class));
     }
@@ -392,3 +390,6 @@ DEFUN(backtrace, "backtrace", (void), "()", "") {
     }
     return out;
 }
+
+DEFINE_SYMBOL(excessive_lisp_nesting_error, "excessive-lisp-nesting-error");
+DEFINE_CONDITION_CLASS(excessive_lisp_nesting_error, error);