Call eval_expr properly within get_operand_value

pythonbpf/binary_ops.py

@@ -3,13 +3,16 @@ from llvmlite import ir
 from logging import Logger
 import logging
 
-from pythonbpf.expr import get_base_type_and_depth, deref_to_depth
+from pythonbpf.expr import get_base_type_and_depth, deref_to_depth, eval_expr
 
 logger: Logger = logging.getLogger(__name__)
 
 
-def get_operand_value(func, operand, builder, local_sym_tab):
+def get_operand_value(
+    func, module, operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab=None
+):
     """Extract the value from an operand, handling variables and constants."""
+    logger.info(f"Getting operand value for: {ast.dump(operand)}")
     if isinstance(operand, ast.Name):
         if operand.id in local_sym_tab:
             var = local_sym_tab[operand.id].var
@@ -17,36 +20,48 @@ def get_operand_value(func, operand, builder, local_sym_tab):
             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
+            return val
         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
+            cst = ir.Constant(ir.IntType(64), int(operand.value))
+            return cst
         raise TypeError(f"Unsupported constant type: {type(operand.value)}")
     elif isinstance(operand, ast.BinOp):
-        res = handle_binary_op_impl(func, operand, builder, local_sym_tab)
-        return res, [res], None
+        res = handle_binary_op_impl(
+            func, module, operand, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+        )
+        return res
+    else:
+        res = eval_expr(
+            func, module, builder, operand, local_sym_tab, map_sym_tab, structs_sym_tab
+        )
+        if res is None:
+            raise ValueError(f"Failed to evaluate call expression: {operand}")
+        val, _ = res
+        return val
     raise TypeError(f"Unsupported operand type: {type(operand)}")
 
 
-def store_through_chain(value, chain, builder):
-    """Store a value through a pointer chain."""
-    if not chain or len(chain) < 2:
-        raise ValueError("Pointer chain must have at least two elements")
-
-    for ptr in reversed(chain[1:]):
-        builder.store(value, ptr)
-        value = ptr
-
-
-def handle_binary_op_impl(func, rval, builder, local_sym_tab):
+def handle_binary_op_impl(
+    func, module, rval, builder, local_sym_tab, map_sym_tab, structs_sym_tab=None
+):
     op = rval.op
-    left, lchain, _ = get_operand_value(func, rval.left, builder, local_sym_tab)
-    right, rchain, _ = get_operand_value(func, rval.right, builder, local_sym_tab)
+    left = get_operand_value(
+        func, module, rval.left, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+    )
+    right = get_operand_value(
+        func, module, rval.right, builder, local_sym_tab, map_sym_tab, structs_sym_tab
+    )
     logger.info(f"left is {left}, right is {right}, op is {op}")
 
-    logger.info(f"left chain: {lchain}, right chain: {rchain}")
+    # NOTE: Before doing the operation, if the operands are integers
+    # we always extend them to i64. The assignment to LHS will take
+    # care of truncation if needed.
+    if isinstance(left.type, ir.IntType) and left.type.width < 64:
+        left = builder.sext(left, ir.IntType(64))
+    if isinstance(right.type, ir.IntType) and right.type.width < 64:
+        right = builder.sext(right, ir.IntType(64))
 
     # Map AST operation nodes to LLVM IR builder methods
     op_map = {
@@ -70,8 +85,19 @@ def handle_binary_op_impl(func, rval, builder, local_sym_tab):
         raise SyntaxError("Unsupported binary operation")
 
 
-def handle_binary_op(func, rval, builder, var_name, local_sym_tab):
-    result = handle_binary_op_impl(func, rval, builder, local_sym_tab)
+def handle_binary_op(
+    func,
+    module,
+    rval,
+    builder,
+    var_name,
+    local_sym_tab,
+    map_sym_tab,
+    structs_sym_tab=None,
+):
+    result = handle_binary_op_impl(
+        func, module, rval, builder, local_sym_tab, map_sym_tab, structs_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 +402,16 @@ def eval_expr(
     elif isinstance(expr, ast.BinOp):
         from pythonbpf.binary_ops import handle_binary_op
 
-        return handle_binary_op(func, expr, builder, None, local_sym_tab)
+        return handle_binary_op(
+            func,
+            module,
+            expr,
+            builder,
+            None,
+            local_sym_tab,
+            map_sym_tab,
+            structs_sym_tab,
+        )
     elif isinstance(expr, ast.Compare):
         return _handle_compare(
             func, module, builder, expr, local_sym_tab, map_sym_tab, structs_sym_tab

tests/passing_tests/assign/helper.py

@@ -0,0 +1,34 @@
+from pythonbpf import bpf, map, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64, c_uint64
+from pythonbpf.maps import HashMap
+
+# NOTE: An example of i64** assignment with binops on the RHS
+
+
+@bpf
+@map
+def last() -> HashMap:
+    return HashMap(key=c_uint64, value=c_uint64, max_entries=3)
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello_world(ctx: c_void_p) -> c_int64:
+    last.update(0, 1)
+    x = last.lookup(0)
+    print(f"{x}")
+    x = x + 1
+    if x == 2:
+        print("Hello, World!")
+    else:
+        print("Goodbye, World!")
+    return
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()