From 45e6ce5e5cf268a286cc3c56f8c426eb7f1762df Mon Sep 17 00:00:00 2001
From: Pragyansh Chaturvedi <pragyanshchaturvedi18@gmail.com>
Date: Mon, 13 Oct 2025 04:01:27 +0530
Subject: [PATCH] Move deref_to_depth to expr/ir_ops.py

---
 pythonbpf/expr/__init__.py           |  3 +-
 pythonbpf/expr/ir_ops.py             | 50 ++++++++++++++++++++++++++++
 pythonbpf/expr/type_normalization.py | 49 ++-------------------------
 3 files changed, 54 insertions(+), 48 deletions(-)
 create mode 100644 pythonbpf/expr/ir_ops.py

diff --git a/pythonbpf/expr/__init__.py b/pythonbpf/expr/__init__.py
index 4b1dac8..4e8f82d 100644
--- a/pythonbpf/expr/__init__.py
+++ b/pythonbpf/expr/__init__.py
@@ -1,5 +1,6 @@
 from .expr_pass import eval_expr, handle_expr, get_operand_value, CallHandlerRegistry
-from .type_normalization import convert_to_bool, get_base_type_and_depth, deref_to_depth
+from .type_normalization import convert_to_bool, get_base_type_and_depth
+from .ir_ops import deref_to_depth
 
 __all__ = [
     "eval_expr",
diff --git a/pythonbpf/expr/ir_ops.py b/pythonbpf/expr/ir_ops.py
new file mode 100644
index 0000000..70f7415
--- /dev/null
+++ b/pythonbpf/expr/ir_ops.py
@@ -0,0 +1,50 @@
+import logging
+from llvmlite import ir
+
+logger = logging.getLogger(__name__)
+
+
+def deref_to_depth(func, builder, val, target_depth):
+    """Dereference a pointer to a certain depth."""
+
+    cur_val = val
+    cur_type = val.type
+
+    for depth in range(target_depth):
+        if not isinstance(val.type, ir.PointerType):
+            logger.error("Cannot dereference further, non-pointer type")
+            return None
+
+        # dereference with null check
+        pointee_type = cur_type.pointee
+        null_check_block = builder.block
+        not_null_block = func.append_basic_block(name=f"deref_not_null_{depth}")
+        merge_block = func.append_basic_block(name=f"deref_merge_{depth}")
+
+        null_ptr = ir.Constant(cur_type, None)
+        is_not_null = builder.icmp_signed("!=", cur_val, null_ptr)
+        logger.debug(f"Inserted null check for pointer at depth {depth}")
+
+        builder.cbranch(is_not_null, not_null_block, merge_block)
+
+        builder.position_at_end(not_null_block)
+        dereferenced_val = builder.load(cur_val)
+        logger.debug(f"Dereferenced to depth {depth - 1}, type: {pointee_type}")
+        builder.branch(merge_block)
+
+        builder.position_at_end(merge_block)
+        phi = builder.phi(pointee_type, name=f"deref_result_{depth}")
+
+        zero_value = (
+            ir.Constant(pointee_type, 0)
+            if isinstance(pointee_type, ir.IntType)
+            else ir.Constant(pointee_type, None)
+        )
+        phi.add_incoming(zero_value, null_check_block)
+
+        phi.add_incoming(dereferenced_val, not_null_block)
+
+        # Continue with phi result
+        cur_val = phi
+        cur_type = pointee_type
+    return cur_val
diff --git a/pythonbpf/expr/type_normalization.py b/pythonbpf/expr/type_normalization.py
index fec53a4..bb5e83b 100644
--- a/pythonbpf/expr/type_normalization.py
+++ b/pythonbpf/expr/type_normalization.py
@@ -1,6 +1,7 @@
-from llvmlite import ir
 import logging
 import ast
+from llvmlite import ir
+from .ir_ops import deref_to_depth
 
 logger = logging.getLogger(__name__)
 
@@ -26,52 +27,6 @@ def get_base_type_and_depth(ir_type):
     return cur_type, depth
 
 
-def deref_to_depth(func, builder, val, target_depth):
-    """Dereference a pointer to a certain depth."""
-
-    cur_val = val
-    cur_type = val.type
-
-    for depth in range(target_depth):
-        if not isinstance(val.type, ir.PointerType):
-            logger.error("Cannot dereference further, non-pointer type")
-            return None
-
-        # dereference with null check
-        pointee_type = cur_type.pointee
-        null_check_block = builder.block
-        not_null_block = func.append_basic_block(name=f"deref_not_null_{depth}")
-        merge_block = func.append_basic_block(name=f"deref_merge_{depth}")
-
-        null_ptr = ir.Constant(cur_type, None)
-        is_not_null = builder.icmp_signed("!=", cur_val, null_ptr)
-        logger.debug(f"Inserted null check for pointer at depth {depth}")
-
-        builder.cbranch(is_not_null, not_null_block, merge_block)
-
-        builder.position_at_end(not_null_block)
-        dereferenced_val = builder.load(cur_val)
-        logger.debug(f"Dereferenced to depth {depth - 1}, type: {pointee_type}")
-        builder.branch(merge_block)
-
-        builder.position_at_end(merge_block)
-        phi = builder.phi(pointee_type, name=f"deref_result_{depth}")
-
-        zero_value = (
-            ir.Constant(pointee_type, 0)
-            if isinstance(pointee_type, ir.IntType)
-            else ir.Constant(pointee_type, None)
-        )
-        phi.add_incoming(zero_value, null_check_block)
-
-        phi.add_incoming(dereferenced_val, not_null_block)
-
-        # Continue with phi result
-        cur_val = phi
-        cur_type = pointee_type
-    return cur_val
-
-
 def _normalize_types(func, builder, lhs, rhs):
     """Normalize types for comparison."""