2 files changed, 18 insertions, 2 deletions
diff --git a/pit/include/lcq/pit/runtime.h b/pit/include/lcq/pit/runtime.h
index b9143cf..a55c2d2 100644
--- a/pit/include/lcq/pit/runtime.h
+++ b/pit/include/lcq/pit/runtime.h
@@ -31,6 +31,13 @@ PIT_DECLARE_HASHTABLE(pit_ref, pit_annotation)
 void pit_annotation_set(struct pit_runtime *rt, pit_ref ref, pit_annotation annotation);
 pit_annotation *pit_annotation_get(struct pit_runtime *rt, pit_ref ref);
 
+/* entry in the backtrace */
+typedef struct {
+    pit_value val;
+    pit_annotation ann;
+} pit_backtrace_entry;
+PIT_DECLARE_VEC(pit_backtrace_entry)
+
 /* entries on a stack used when traversing trees of values */
 typedef struct {
     enum {
@@ -63,6 +70,7 @@ typedef struct pit_runtime {
     pit_vec(pit_value) *expr_stack; /* stack of subexpressions to evaluate during evaluation */
     pit_vec(pit_value) *result_stack; /* stack of intermediate values during evaluation */
     pit_vec(pit_traversal_entry) *traversal; /* intermediate stack used during tree traversal */
+    pit_vec(pit_backtrace_entry) *backtrace; /* stack of enclosing function calls */
     /* bookkeeping */
     /* "frozen" values offsets: values before these offsets are immutable, and we can reset here later */
     i64 frozen_values, frozen_symtab;
diff --git a/pit/include/lcq/pit/runtime/dump.h b/pit/include/lcq/pit/runtime/dump.h
index 2aeba2f..600604e 100644
--- a/pit/include/lcq/pit/runtime/dump.h
+++ b/pit/include/lcq/pit/runtime/dump.h
@@ -3,9 +3,17 @@
 
 #include <lcq/pit/runtime.h>
 
-typedef i64 (*pit_dump_callback)(u8 *buf, i64 len, void *data);
+typedef enum {
+    PIT_DUMP_CONDITION_NORMAL = 0,
+    PIT_DUMP_CONDITION_FULL = -1,
+    PIT_DUMP_CONDITION_STACK_UNDERFLOW = -2,
+    PIT_DUMP_CONDITION_STACK_OVERFLOW = -3,
+    PIT_DUMP_CONDITION_MALFORMED_TRAVERSAL = -4,
+} pit_dump_condition;
 
-void pit_dump_with_callback(pit_runtime *rt, pit_value top, bool readable, pit_dump_callback write, void *data);
+typedef pit_dump_condition (*pit_dump_callback)(u8 *buf, i64 len, void *data);
+
+pit_dump_condition pit_dump_with_callback(pit_runtime *rt, pit_value top, bool readable, pit_dump_callback write, void *data);
 
 /* pretty-print a pit value
    if readable is true, try to produce output that can be machine-read (quotes on strings, etc) */