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

This commit is contained in:
Pragyansh Chaturvedi
2025-10-10 20:36:37 +05:30
parent 9febadffd3
commit 7529820c0b
3 changed files with 24 additions and 45 deletions

View File

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

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@ -3,34 +3,21 @@ from llvmlite import ir
from logging import Logger from logging import Logger
import logging import logging
from pythonbpf.expr import get_base_type_and_depth, deref_to_depth
logger: Logger = logging.getLogger(__name__) logger: Logger = logging.getLogger(__name__)
def deref_to_val(var, builder): def get_operand_value(func, operand, builder, local_sym_tab):
"""Dereference a variable to get its value and pointer chain."""
logger.info(f"Dereferencing {var}, type is {var.type}")
chain = [var]
cur = var
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}")
def get_operand_value(operand, builder, local_sym_tab):
"""Extract the value from an operand, handling variables and constants.""" """Extract the value from an operand, handling variables and constants."""
if isinstance(operand, ast.Name): if isinstance(operand, ast.Name):
if operand.id in local_sym_tab: if operand.id in local_sym_tab:
var = local_sym_tab[operand.id].var var = local_sym_tab[operand.id].var
val, chain = deref_to_val(var, builder) var_type = var.type
return val, chain, var 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}") raise ValueError(f"Undefined variable: {operand.id}")
elif isinstance(operand, ast.Constant): elif isinstance(operand, ast.Constant):
if isinstance(operand.value, int): if isinstance(operand.value, int):
@ -38,7 +25,7 @@ def get_operand_value(operand, builder, local_sym_tab):
return cst, [cst], None return cst, [cst], None
raise TypeError(f"Unsupported constant type: {type(operand.value)}") raise TypeError(f"Unsupported constant type: {type(operand.value)}")
elif isinstance(operand, ast.BinOp): 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 return res, [res], None
raise TypeError(f"Unsupported operand type: {type(operand)}") raise TypeError(f"Unsupported operand type: {type(operand)}")
@ -53,10 +40,10 @@ def store_through_chain(value, chain, builder):
value = ptr 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 op = rval.op
left, lchain, _ = get_operand_value(rval.left, builder, local_sym_tab) left, lchain, _ = get_operand_value(func, rval.left, builder, local_sym_tab)
right, rchain, _ = get_operand_value(rval.right, 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 is {left}, right is {right}, op is {op}")
logger.info(f"left chain: {lchain}, right chain: {rchain}") 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") raise SyntaxError("Unsupported binary operation")
def handle_binary_op(rval, builder, var_name, local_sym_tab): def handle_binary_op(func, rval, builder, var_name, local_sym_tab):
result = handle_binary_op_impl(rval, builder, local_sym_tab) result = handle_binary_op_impl(func, rval, builder, local_sym_tab)
if var_name and var_name in local_sym_tab: if var_name and var_name in local_sym_tab:
logger.info( logger.info(
f"Storing result {result} into variable {local_sym_tab[var_name].var}" f"Storing result {result} into variable {local_sym_tab[var_name].var}"

View File

@ -402,7 +402,7 @@ def eval_expr(
elif isinstance(expr, ast.BinOp): elif isinstance(expr, ast.BinOp):
from pythonbpf.binary_ops import handle_binary_op 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): elif isinstance(expr, ast.Compare):
return _handle_compare( return _handle_compare(
func, module, builder, expr, local_sym_tab, map_sym_tab, structs_sym_tab func, module, builder, expr, local_sym_tab, map_sym_tab, structs_sym_tab