Fix printk handler to comply with new symtab convention

Author: r41k0u

pythonbpf/bpf_helper_handler.py

@@ -121,7 +121,8 @@ def bpf_printk_emitter(call, map_ptr, module, builder, func, local_sym_tab=None,
                 "Warning: bpf_printk supports up to 3 arguments, extra arguments will be ignored.")
 
         for expr in exprs[:3]:
-            val = eval_expr(func, module, builder, expr, local_sym_tab, None)
+            val, _ = eval_expr(func, module, builder,
+                               expr, local_sym_tab, None)
             if val:
                 if isinstance(val.type, ir.PointerType):
                     val = builder.ptrtoint(val, ir.IntType(64))
@@ -137,7 +138,6 @@ def bpf_printk_emitter(call, map_ptr, module, builder, func, local_sym_tab=None,
                 print(
                     "Warning: Failed to evaluate expression for bpf_printk argument. It will be converted to 0.")
                 args.append(ir.Constant(ir.IntType(64), 0))
-
         fn_type = ir.FunctionType(ir.IntType(
             64), [ir.PointerType(), ir.IntType(32)], var_arg=True)
         fn_ptr_type = ir.PointerType(fn_type)

pythonbpf/codegen.py

@@ -93,6 +93,7 @@ def compile_to_ir(filename: str, output: str):
 
     module.add_named_metadata("llvm.ident", ["llvmlite PythonBPF v0.0.1"])
 
+    print(f"IR written to {output}")
     with open(output, "w") as f:
         f.write(f"source_filename = \"{filename}\"\n")
         f.write(str(module))
@@ -118,6 +119,7 @@ def compile():
 
     print(f"Object written to {o_file}, {ll_file} can be removed")
 
+
 def BPF() -> BpfProgram:
     caller_frame = inspect.stack()[1]
     caller_file = Path(caller_frame.filename).resolve()
@@ -129,5 +131,5 @@ def BPF() -> BpfProgram:
         "llc", "-march=bpf", "-filetype=obj", "-O2",
         str(ll_file), "-o", str(o_file)
     ], check=True)
-    
+
     return BpfProgram(str(o_file))

pythonbpf/expr_pass.py

@@ -3,7 +3,7 @@
 
 
 def eval_expr(func, module, builder, expr, local_sym_tab, map_sym_tab, structs_sym_tab=None, local_var_metadata=None):
-    print(f"Evaluating expression: {expr}")
+    print(f"Evaluating expression: {ast.dump(expr)}")
     if isinstance(expr, ast.Name):
         if expr.id in local_sym_tab:
             var = local_sym_tab[expr.id][0]

pythonbpf/functions_pass.py

@@ -61,7 +61,7 @@ def handle_assign(func, module, builder, stmt, map_sym_tab, local_sym_tab, struc
                 if val is None:
                     print("Failed to evaluate struct field assignment")
                     return
-                builder.store(val, field_ptr)
+                builder.store(val[0], field_ptr)
                 print(f"Assigned to struct field {var_name}.{field_name}")
                 return
     elif isinstance(rval, ast.Constant):
@@ -114,7 +114,7 @@ def handle_assign(func, module, builder, stmt, map_sym_tab, local_sym_tab, struc
                 # var.align = 8
                 val = handle_helper_call(
                     rval, module, builder, func, local_sym_tab, map_sym_tab, structs_sym_tab, local_var_metadata)
-                builder.store(val, local_sym_tab[var_name][0])
+                builder.store(val[0], local_sym_tab[var_name][0])
                 # local_sym_tab[var_name] = var
                 print(f"Assigned constant {rval.func.id} to {var_name}")
             elif call_type == "deref" and len(rval.args) == 1:
@@ -125,7 +125,7 @@ def handle_assign(func, module, builder, stmt, map_sym_tab, local_sym_tab, struc
                     print("Failed to evaluate deref argument")
                     return
                 print(f"Dereferenced value: {val}, storing in {var_name}")
-                builder.store(val, local_sym_tab[var_name][0])
+                builder.store(val[0], local_sym_tab[var_name][0])
                 # local_sym_tab[var_name] = var
                 print(f"Dereferenced and assigned to {var_name}")
             elif call_type in structs_sym_tab and len(rval.args) == 0:
@@ -155,7 +155,7 @@ def handle_assign(func, module, builder, stmt, map_sym_tab, local_sym_tab, struc
                             rval, module, builder, func, local_sym_tab, map_sym_tab, structs_sym_tab, local_var_metadata)
                         # var = builder.alloca(ir.IntType(64), name=var_name)
                         # var.align = 8
-                        builder.store(val, local_sym_tab[var_name][0])
+                        builder.store(val[0], local_sym_tab[var_name][0])
                         # local_sym_tab[var_name] = var
             else:
                 print("Unsupported assignment call structure")
@@ -462,7 +462,6 @@ def process_bpf_chunk(func_node, module, return_type, map_sym_tab, structs_sym_t
 
     process_func_body(module, builder, func_node, func,
                       ret_type, map_sym_tab, structs_sym_tab)
-
     return func