fix: use correct rollback tails for empty frames without history

src/tests/simple_tests/storage.rs

@@ -2,41 +2,35 @@
 mod tests {
     use crate::tests::simple_tests::{asm_tests::run_asm_based_test, Options};
 
-    #[test_log::test]
-    fn test_pubdata_and_storage_writes() {
+    fn test_snapshot_every_cycle(dir: &str, additional_contracts: &[i32]) {
         run_asm_based_test(
-            "src/tests/simple_tests/testdata/log/storage/storage_writes",
-            &[],
+            &format!("src/tests/simple_tests/testdata/{}", dir),
+            additional_contracts,
             Options {
+                // Do only 1 cycle per VM snapshot to really test all the boundary conditions.
                 cycles_per_vm_snapshot: 1,
                 ..Default::default()
             },
-        );
+        )
+    }
+
+    #[test_log::test]
+    fn test_pubdata_and_storage_writes() {
+        test_snapshot_every_cycle("log/storage/storage_writes", &[]);
     }
 
     #[test_log::test]
     fn test_storage_reads() {
-        run_asm_based_test(
-            "src/tests/simple_tests/testdata/log/storage/storage_reads",
-            &[],
-            Options {
-                // Do only 1 cycle per VM snapshot to really test all the boundary conditions.
-                cycles_per_vm_snapshot: 1,
-                ..Default::default()
-            },
-        )
+        test_snapshot_every_cycle("log/storage/storage_reads", &[]);
+    }
+
+    #[test_log::test]
+    fn test_storage_write_after_panic() {
+        test_snapshot_every_cycle("log/storage/storage_write_after_panic", &[]);
     }
 
     #[test_log::test]
     fn test_storage_pubdata_refunds() {
-        run_asm_based_test(
-            "src/tests/simple_tests/testdata/log/storage/storage_pubdata_refunds",
-            &[],
-            Options {
-                // Do only 1 cycle per VM snapshot to really test all the boundary conditions.
-                cycles_per_vm_snapshot: 1,
-                ..Default::default()
-            },
-        );
+        test_snapshot_every_cycle("log/storage/storage_pubdata_refunds", &[]);
     }
 }

src/tests/simple_tests/testdata/log/storage/storage_write_after_panic/entry.asm

@@ -0,0 +1,26 @@
+        .text
+        .file	"Test_26"
+        .rodata.cst32
+        .p2align	5
+        .text
+        .globl	__entry
+__entry:
+.main:  
+        add 1000, r0, r3
+        near_call r3, @test_panic, @expected_panic
+        revert("Near call not panicked")
+
+test_panic:
+        add 1000, r0, r3
+        near_call r3, @test_panic2, @expected_panic2
+
+expected_panic:
+        ; check that we can access storage after panic
+        log.swrite r0, r0, r0
+        ret.ok r0
+
+test_panic2:
+        ret.ok r0
+
+expected_panic2:
+        ret.panic r0

src/witness/callstack_handler.rs

@@ -124,7 +124,7 @@ pub struct CallstackWithAuxData {
     pub full_history: Vec<CallstackActionHistoryEntry>,
     pub log_queue_access_snapshots: Vec<(u32, RenumeratedQueryIndex)>,
     pub log_access_history: Vec<(u32, QueryMarker)>,
-    pub child_into_parent: HashMap<usize, usize>,
+    pub child_into_parent: HashMap<usize, usize>, // ! TODO deadcode
     pub flat_new_frames_history: Vec<(u32, CallStackEntry)>,
 }
 

src/witness/oracle.rs

@@ -245,6 +245,7 @@ pub fn create_artifacts_from_tracer<
     let forward = callstack_with_aux_data.current_entry.forward_queue.clone();
     let rollbacks = callstack_with_aux_data.current_entry.rollback_queue.clone();
 
+    // TODO deadcode?
     let mut query_id_into_cycle_index = BTreeMap::new();
 
     for (cycle, marker) in callstack_with_aux_data.log_access_history.iter() {
@@ -266,6 +267,8 @@ pub fn create_artifacts_from_tracer<
     let mut original_log_queue_states = vec![];
     let mut chain_of_states = vec![];
     let mut original_log_queue_simulator = None;
+
+    // TODO deadcode?
     let mut marker_into_queue_position_renumeration_index: HashMap<QueryMarker, usize> =
         HashMap::new();
 
@@ -276,6 +279,8 @@ pub fn create_artifacts_from_tracer<
     let mut sponges_data: HashMap<u32, LogAccessSpongesInfo<GoldilocksField>> = HashMap::new();
 
     let mut global_beginnings_of_frames: BTreeMap<usize, u32> = BTreeMap::new();
+
+    // TODO deadcode?
     let mut actions_in_each_frame: BTreeMap<usize, Vec<(u32, QueryMarker, usize)>> =
         BTreeMap::new();
 
@@ -534,31 +539,22 @@ pub fn create_artifacts_from_tracer<
         .last()
         .map(|el| el.2 .1)
         .unwrap_or([GoldilocksField::ZERO; QUEUE_STATE_WIDTH]);
-    let mut frame_rollback_tails = BTreeMap::new();
 
+    // we want to save rollback tails for every frame
+    let mut frame_rollback_tails = BTreeMap::new();
     let mut rollback_queue_initial_tails_for_new_frames = vec![];
     let max_frame_idx = callstack_with_aux_data.monotonic_frame_counter;
-
     for frame_index in 0..max_frame_idx {
-        if frame_index == 0 {
-            let tail = global_end_of_storage_log;
-            frame_rollback_tails.insert(frame_index, tail);
-            let frame_beginning_cycle = global_beginnings_of_frames[&frame_index];
-            rollback_queue_initial_tails_for_new_frames.push((frame_beginning_cycle, tail));
-            continue;
-        }
-
         let rollback_tail_marker = ExtendedLogQuery::FrameRollbackTailMarker(frame_index);
-        // wherever we have this marker we should look at the tail of the item right before it
-        let pos = log_position_mapping[&rollback_tail_marker];
-        let tail = if pos == -1 {
-            // empty
-            global_end_of_storage_log
+        // log_position_mapping should contain a pointer to the last state change in the chain_of_states before the rollback marker
+        // pointer is -1 if there were no such changes
+        let pointer = log_position_mapping[&rollback_tail_marker];
+        let tail = if pointer != -1 {
+            // take tail "after" item at pointer
+            chain_of_states[pointer as usize].2 .1
         } else {
-            let pointer = pos as usize;
-            let element = chain_of_states[pointer].2 .1;
-
-            element
+            // We do not have any logs in history before the rollback of this frame
+            [GoldilocksField::ZERO; QUEUE_STATE_WIDTH]
         };
 
         frame_rollback_tails.insert(frame_index, tail);