support binary ops with vmlinux enums

Author: varun-r-mallya

pythonbpf/codegen.py

@@ -67,7 +67,7 @@ def processor(source_code, filename, module):
     globals_processing(tree, module)
     structs_sym_tab = structs_proc(tree, module, bpf_chunks)
     map_sym_tab = maps_proc(tree, module, bpf_chunks)
-    func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab, vmlinux_symtab)
+    func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab)
 
     globals_list_creation(tree, module)
 

pythonbpf/expr/expr_pass.py

@@ -142,7 +142,12 @@ def get_operand_value(
             logger.info(f"var is {var}, base_type is {base_type}, depth is {depth}")
             val = deref_to_depth(func, builder, var, depth)
             return val
-        raise ValueError(f"Undefined variable: {operand.id}")
+        else:
+            # Check if it's a vmlinux enum/constant
+            vmlinux_result = VmlinuxHandlerRegistry.handle_name(operand.id)
+            if vmlinux_result is not None:
+                val, _ = vmlinux_result
+                return val
     elif isinstance(operand, ast.Constant):
         if isinstance(operand.value, int):
             cst = ir.Constant(ir.IntType(64), int(operand.value))

tests/passing_tests/vmlinux/simple_struct_test.py

@@ -1,4 +1,4 @@
-from pythonbpf import bpf, section, bpfglobal, compile_to_ir
+from pythonbpf import bpf, section, bpfglobal, compile_to_ir, compile
 from vmlinux import TASK_COMM_LEN  # noqa: F401
 from vmlinux import struct_trace_event_raw_sys_enter  # noqa: F401
 
@@ -16,7 +16,8 @@
 @bpf
 @section("tracepoint/syscalls/sys_enter_execve")
 def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
-    print("Hello, World")
+    a = 2 + TASK_COMM_LEN + TASK_COMM_LEN
+    print(f"Hello, World{a}")
     return c_int64(TASK_COMM_LEN)
 
 
@@ -27,3 +28,4 @@ def LICENSE() -> str:
 
 
 compile_to_ir("simple_struct_test.py", "simple_struct_test.ll")
+compile()