Fix hashmap access in direct_assign.py

pythonbpf/binary_ops.py

@@ -9,6 +9,7 @@ logger: Logger = logging.getLogger(__name__)
 def recursive_dereferencer(var, builder):
     """dereference until primitive type comes out"""
     # TODO: Not worrying about stack overflow for now
+    logger.info(f"Dereferencing {var}, type is {var.type}")
     if isinstance(var.type, ir.PointerType):
         a = builder.load(var)
         return recursive_dereferencer(a, builder)
@@ -18,7 +19,7 @@ def recursive_dereferencer(var, builder):
         raise TypeError(f"Unsupported type for dereferencing: {var.type}")
 
 
-def get_operand_value(operand, module, builder, local_sym_tab):
+def get_operand_value(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:
@@ -29,14 +30,14 @@ def get_operand_value(operand, module, builder, local_sym_tab):
             return ir.Constant(ir.IntType(64), operand.value)
         raise TypeError(f"Unsupported constant type: {type(operand.value)}")
     elif isinstance(operand, ast.BinOp):
-        return handle_binary_op_impl(operand, module, builder, local_sym_tab)
+        return handle_binary_op_impl(operand, builder, local_sym_tab)
     raise TypeError(f"Unsupported operand type: {type(operand)}")
 
 
-def handle_binary_op_impl(rval, module, builder, local_sym_tab):
+def handle_binary_op_impl(rval, builder, local_sym_tab):
     op = rval.op
-    left = get_operand_value(rval.left, module, builder, local_sym_tab)
+    left = get_operand_value(rval.left, builder, local_sym_tab)
-    right = get_operand_value(rval.right, module, builder, local_sym_tab)
+    right = get_operand_value(rval.right, builder, local_sym_tab)
     logger.info(f"left is {left}, right is {right}, op is {op}")
 
     # Map AST operation nodes to LLVM IR builder methods
@@ -61,8 +62,8 @@ def handle_binary_op_impl(rval, module, builder, local_sym_tab):
         raise SyntaxError("Unsupported binary operation")
 
 
-def handle_binary_op(rval, module, builder, var_name, local_sym_tab):
+def handle_binary_op(rval, builder, var_name, local_sym_tab):
-    result = handle_binary_op_impl(rval, module, builder, local_sym_tab)
+    result = handle_binary_op_impl(rval, builder, local_sym_tab)
     if var_name in local_sym_tab:
         builder.store(result, local_sym_tab[var_name].var)
     return result, result.type

pythonbpf/functions_pass.py

@@ -233,7 +233,7 @@ def handle_assign(
         else:
             logger.info("Unsupported assignment call function type")
     elif isinstance(rval, ast.BinOp):
-        handle_binary_op(rval, module, builder, var_name, local_sym_tab)
+        handle_binary_op(rval, builder, var_name, local_sym_tab)
     else:
         logger.info("Unsupported assignment value type")
 
@@ -406,9 +406,7 @@ def process_stmt(
                     did_return = True
             elif isinstance(stmt.value.args[0], ast.BinOp):
                 # TODO: Should be routed through eval_expr
-                val = handle_binary_op(
+                val = handle_binary_op(stmt.value.args[0], builder, None, local_sym_tab)
-                    stmt.value.args[0], module, builder, None, local_sym_tab
-                )
                 if val is None:
                     raise ValueError("Failed to evaluate return expression")
                 if val[1] != ret_type:

tests/failing_tests/direct_assign.py

@@ -4,6 +4,18 @@ from pythonbpf.maps import HashMap
 
 from ctypes import c_void_p, c_int64
 
+# NOTE: I have decided to not fix this example for now.
+# The issue is in line 31, where we are passing an expression.
+# The update helper expects a pointer type. But the problem is
+# that we must allocate the space for said pointer in the first
+# basic block. As that usage is in a different basic block, we
+# are unable to cast the expression to a pointer type. (as we never
+# allocated space for it).
+# Shall we change our space allocation logic? That allows users to
+# spam the same helper with the same args, and still run out of
+# stack space. So we consider this usage invalid for now.
+# Might fix it later.
+
 
 @bpf
 @map
@@ -14,12 +26,12 @@ def count() -> HashMap:
 @bpf
 @section("xdp")
 def hello_world(ctx: c_void_p) -> c_int64:
-    prev = count().lookup(0)
+    prev = count.lookup(0)
     if prev:
-        count().update(0, prev + 1)
+        count.update(0, prev + 1)
         return XDP_PASS
     else:
-        count().update(0, 1)
+        count.update(0, 1)
 
     return XDP_PASS