Lexical jumps

src/stack.h

@@ -3,6 +3,7 @@
 
 #include "base.h"
 
+#include <setjmp.h>
 #include <stdnoreturn.h>
 
 enum StackFrameKind {
@@ -11,6 +12,7 @@ enum StackFrameKind {
     STACK_FRAME_UNWIND_PROTECT,
     STACK_FRAME_HANDLER_BIND,
     STACK_FRAME_DYNAMIC_BINDING,
+    STACK_FRAME_BLOCK,
 };
 
 #define LISP_STACK_MAX_DEPTH          4096
@@ -58,6 +60,12 @@ struct _StackFrame {
             LispVal *symbol;
             LispVal *old_value;
         } dynamic_binding;
+        struct {
+            LispVal *tag;
+            jmp_buf *target;
+            LispVal *volatile *value_ptr;
+            StackFrame *unwind_to;
+        } block;
     };
 };
 
@@ -139,11 +147,16 @@ static ALWAYS_INLINE LispVal *UNWIND_AND_RETURN(StackFrame *frame,
 
 noreturn void lisp_signal(LispVal *name, LispVal *data);
 
+DECLARE_FUNCTION(block, (LispVal * name, LispVal *body));
+DECLARE_FUNCTION(return_from, (LispVal * name, LispVal *value));
+
 /**
  * Backtraces have the form (name fobj evaled? args)
  */
 DECLARE_FUNCTION(backtrace, (void) );
 
+DECLARE_SYMBOL(no_such_block_error);
+MAKE_CONDITION_CLASS(no_such_block_error);
 DECLARE_SYMBOL(excessive_lisp_nesting_error);
 MAKE_CONDITION_CLASS(excessive_lisp_nesting_error);