refactor(spec-specs): refactor EIP-7928 to use nested context frames

src/ethereum/forks/amsterdam/block_access_lists/__init__.py

@@ -17,47 +17,17 @@
     rlp_encode_block_access_list,
     validate_block_access_list_against_execution,
 )
-from .tracker import (
-    StateChangeTracker,
-    begin_call_frame,
-    commit_call_frame,
-    handle_in_transaction_selfdestruct,
-    normalize_balance_changes,
-    prepare_balance_tracking,
-    rollback_call_frame,
-    set_block_access_index,
-    track_address_access,
-    track_balance_change,
-    track_code_change,
-    track_nonce_change,
-    track_storage_read,
-    track_storage_write,
-)
 
 __all__ = [
     "BlockAccessListBuilder",
-    "StateChangeTracker",
     "add_balance_change",
     "add_code_change",
     "add_nonce_change",
     "add_storage_read",
     "add_storage_write",
     "add_touched_account",
-    "begin_call_frame",
     "build_block_access_list",
-    "commit_call_frame",
     "compute_block_access_list_hash",
-    "handle_in_transaction_selfdestruct",
-    "normalize_balance_changes",
-    "prepare_balance_tracking",
-    "rollback_call_frame",
-    "set_block_access_index",
     "rlp_encode_block_access_list",
-    "track_address_access",
-    "track_balance_change",
-    "track_code_change",
-    "track_nonce_change",
-    "track_storage_read",
-    "track_storage_write",
     "validate_block_access_list_against_execution",
 ]

src/ethereum/forks/amsterdam/block_access_lists/builder.py

@@ -14,7 +14,7 @@
 """
 
 from dataclasses import dataclass, field
-from typing import Dict, List, Set
+from typing import TYPE_CHECKING, Dict, List, Set
 
 from ethereum_types.bytes import Bytes, Bytes32
 from ethereum_types.numeric import U64, U256
@@ -31,6 +31,9 @@
     StorageChange,
 )
 
+if TYPE_CHECKING:
+    from ..state_tracker import StateChanges
+
 
 @dataclass
 class AccountData:
@@ -275,14 +278,15 @@ def add_nonce_change(
     ensure_account(builder, address)
 
     # Check if we already have a nonce change for this tx_index and update it
-    # This ensures we only track the final nonce per transaction
+    # This ensures we only track the final (highest) nonce per transaction
     existing_changes = builder.accounts[address].nonce_changes
     for i, existing in enumerate(existing_changes):
         if existing.block_access_index == block_access_index:
-            # Update the existing nonce change with the new nonce
-            existing_changes[i] = NonceChange(
-                block_access_index=block_access_index, new_nonce=new_nonce
-            )
+            # Keep the highest nonce value
+            if new_nonce > existing.new_nonce:
+                existing_changes[i] = NonceChange(
+                    block_access_index=block_access_index, new_nonce=new_nonce
+                )
             return
 
     # No existing change for this tx_index, add a new one
@@ -374,11 +378,11 @@ def add_touched_account(
     ensure_account(builder, address)
 
 
-def build_block_access_list(
+def _build_from_builder(
     builder: BlockAccessListBuilder,
 ) -> BlockAccessList:
     """
-    Build the final [`BlockAccessList`] from accumulated changes.
+    Build the final [`BlockAccessList`] from a builder (internal helper).
 
     Constructs a deterministic block access list by sorting all accumulated
     changes. The resulting list is ordered by:
@@ -445,3 +449,77 @@ def build_block_access_list(
     account_changes_list.sort(key=lambda x: x.address)
 
     return BlockAccessList(account_changes=tuple(account_changes_list))
+
+
+def build_block_access_list(
+    state_changes: "StateChanges",
+) -> BlockAccessList:
+    """
+    Build a [`BlockAccessList`] from a StateChanges frame.
+
+    Converts the accumulated state changes from the frame-based architecture
+    into the final deterministic BlockAccessList format.
+
+    Parameters
+    ----------
+    state_changes :
+        The block-level StateChanges frame containing all changes from the block.
+
+    Returns
+    -------
+    block_access_list :
+        The final sorted and encoded block access list.
+
+    [`BlockAccessList`]: ref:ethereum.forks.amsterdam.block_access_lists.rlp_types.BlockAccessList  # noqa: E501
+    [`StateChanges`]: ref:ethereum.forks.amsterdam.state_tracker.StateChanges
+
+    """
+    builder = BlockAccessListBuilder()
+
+    # Add all touched addresses
+    for address in state_changes.touched_addresses:
+        add_touched_account(builder, address)
+
+    # Add all storage reads
+    for address, slot in state_changes.storage_reads:
+        add_storage_read(builder, address, slot)
+
+    # Add all storage writes, filtering net-zero changes
+    for (
+        address,
+        slot,
+        block_access_index,
+    ), value in state_changes.storage_writes.items():
+        # Check if this is a net-zero change by comparing with pre-state
+        if (address, slot) in state_changes.pre_storage:
+            if state_changes.pre_storage[(address, slot)] == value:
+                # Net-zero change - convert to read only
+                add_storage_read(builder, address, slot)
+                continue
+
+        # Convert U256 to Bytes32 for storage
+        value_bytes = Bytes32(value.to_bytes(U256(32), "big"))
+        add_storage_write(
+            builder, address, slot, block_access_index, value_bytes
+        )
+
+    # Add all balance changes (balance_changes is keyed by (address, index))
+    for (
+        address,
+        block_access_index,
+    ), new_balance in state_changes.balance_changes.items():
+        add_balance_change(builder, address, block_access_index, new_balance)
+
+    # Add all nonce changes
+    for address, block_access_index, new_nonce in state_changes.nonce_changes:
+        add_nonce_change(builder, address, block_access_index, new_nonce)
+
+    # Add all code changes
+    # Filtering happens at transaction level in eoa_delegation.py
+    for (
+        address,
+        block_access_index,
+    ), new_code in state_changes.code_changes.items():
+        add_code_change(builder, address, block_access_index, new_code)
+
+    return _build_from_builder(builder)

src/ethereum/forks/amsterdam/block_access_lists/rlp_utils.py

@@ -216,10 +216,10 @@ def validate_block_access_list_against_execution(
     # 4. If Block Access List builder provided, validate against it
     # by comparing hashes
     if block_access_list_builder is not None:
-        from .builder import build_block_access_list
+        from .builder import _build_from_builder
 
         # Build a Block Access List from the builder
-        expected_block_access_list = build_block_access_list(
+        expected_block_access_list = _build_from_builder(
             block_access_list_builder
         )