Allow int** pointers to store binops of type int** op int

Author: r41k0u

pythonbpf/assign_pass.py

@@ -1,7 +1,7 @@
 import ast
 import logging
 from llvmlite import ir
-from pythonbpf.expr import eval_expr, get_base_type_and_depth
+from pythonbpf.expr import eval_expr
 
 logger = logging.getLogger(__name__)
 
@@ -37,10 +37,8 @@ def handle_variable_assignment(
         return False
 
     val, val_type = val_result
+    logger.info(f"Evaluated value for {var_name}: {val} of type {val_type}, {var_type}")
     if val_type != var_type:
-        logger.info(f"val = {val}")
-        logger.info(f"var = {var_ptr}")
-        logger.info(f"truthy {var_type}")
         if isinstance(val_type, ir.IntType) and isinstance(var_type, ir.IntType):
             # Allow implicit int widening
             if val_type.width < var_type.width:
@@ -50,23 +48,17 @@ def handle_variable_assignment(
                 val = builder.trunc(val, var_type)
                 logger.info(f"Implicitly truncated int for variable {var_name}")
         elif isinstance(val_type, ir.IntType) and isinstance(var_type, ir.PointerType):
-            ptr_target, ptr_depth = get_base_type_and_depth(var_type)
-            if ptr_target.width > val_type.width:
-                val = builder.sext(val, ptr_target)
-            elif ptr_target.width < val_type.width:
-                val = builder.trunc(val, ptr_target)
-
-            if ptr_depth > 1:
-                # NOTE: This is assignment to a PTR_TO_MAP_VALUE_OR_NULL
-                var_ptr_tmp = local_sym_tab[f"{var_name}_tmp"].var
-                builder.store(val, var_ptr_tmp)
-                val = var_ptr_tmp
+            # NOTE: This is assignment to a PTR_TO_MAP_VALUE_OR_NULL
+            logger.info(
+                f"Creating temporary variable for pointer assignment to {var_name}"
+            )
+            var_ptr_tmp = local_sym_tab[f"{var_name}_tmp"].var
+            builder.store(val, var_ptr_tmp)
+            val = var_ptr_tmp
         else:
             logger.error(
                 f"Type mismatch for variable {var_name}: {val_type} vs {var_type}"
             )
-            logger.error(f"var_type: {isinstance(var_type, ir.PointerType)}")
-            logger.error(f"val_type: {isinstance(val_type, ir.IntType)}")
             return False
 
     builder.store(val, var_ptr)

pythonbpf/binary_ops.py

@@ -3,42 +3,29 @@
 from logging import Logger
 import logging
 
-logger: Logger = logging.getLogger(__name__)
-
-
-def deref_to_val(var, builder):
-    """Dereference a variable to get its value and pointer chain."""
-    logger.info(f"Dereferencing {var}, type is {var.type}")
-
-    chain = [var]
-    cur = var
+from pythonbpf.expr import get_base_type_and_depth, deref_to_depth
 
-    while isinstance(cur.type, ir.PointerType):
-        cur = builder.load(cur)
-        chain.append(cur)
-
-    if isinstance(cur.type, ir.IntType):
-        logger.info(f"dereference chain: {chain}")
-        return cur, chain
-    else:
-        raise TypeError(f"Unsupported type for dereferencing: {cur.type}")
+logger: Logger = logging.getLogger(__name__)
 
 
-def get_operand_value(operand, builder, local_sym_tab):
+def get_operand_value(func, operand, builder, local_sym_tab):
     """Extract the value from an operand, handling variables and constants."""
     if isinstance(operand, ast.Name):
         if operand.id in local_sym_tab:
             var = local_sym_tab[operand.id].var
-            val, chain = deref_to_val(var, builder)
-            return val, chain, var
+            var_type = var.type
+            base_type, depth = get_base_type_and_depth(var_type)
+            logger.info(f"var is {var}, base_type is {base_type}, depth is {depth}")
+            val = deref_to_depth(func, builder, var, depth)
+            return val, [val], var
         raise ValueError(f"Undefined variable: {operand.id}")
     elif isinstance(operand, ast.Constant):
         if isinstance(operand.value, int):
             cst = ir.Constant(ir.IntType(64), operand.value)
             return cst, [cst], None
         raise TypeError(f"Unsupported constant type: {type(operand.value)}")
     elif isinstance(operand, ast.BinOp):
-        res = handle_binary_op_impl(operand, builder, local_sym_tab)
+        res = handle_binary_op_impl(func, operand, builder, local_sym_tab)
         return res, [res], None
     raise TypeError(f"Unsupported operand type: {type(operand)}")
 
@@ -53,10 +40,10 @@ def store_through_chain(value, chain, builder):
         value = ptr
 
 
-def handle_binary_op_impl(rval, builder, local_sym_tab):
+def handle_binary_op_impl(func, rval, builder, local_sym_tab):
     op = rval.op
-    left, lchain, _ = get_operand_value(rval.left, builder, local_sym_tab)
-    right, rchain, _ = get_operand_value(rval.right, builder, local_sym_tab)
+    left, lchain, _ = get_operand_value(func, rval.left, builder, local_sym_tab)
+    right, rchain, _ = get_operand_value(func, rval.right, builder, local_sym_tab)
     logger.info(f"left is {left}, right is {right}, op is {op}")
 
     logger.info(f"left chain: {lchain}, right chain: {rchain}")
@@ -83,8 +70,8 @@ def handle_binary_op_impl(rval, builder, local_sym_tab):
         raise SyntaxError("Unsupported binary operation")
 
 
-def handle_binary_op(rval, builder, var_name, local_sym_tab):
-    result = handle_binary_op_impl(rval, builder, local_sym_tab)
+def handle_binary_op(func, rval, builder, var_name, local_sym_tab):
+    result = handle_binary_op_impl(func, rval, builder, local_sym_tab)
     if var_name and var_name in local_sym_tab:
         logger.info(
             f"Storing result {result} into variable {local_sym_tab[var_name].var}"

pythonbpf/expr/expr_pass.py

@@ -402,7 +402,7 @@ def eval_expr(
     elif isinstance(expr, ast.BinOp):
         from pythonbpf.binary_ops import handle_binary_op
 
-        return handle_binary_op(expr, builder, None, local_sym_tab)
+        return handle_binary_op(func, expr, builder, None, local_sym_tab)
     elif isinstance(expr, ast.Compare):
         return _handle_compare(
             func, module, builder, expr, local_sym_tab, map_sym_tab, structs_sym_tab