Merge pull request #59 from pythonbpf/vmlinux-handler

LGTM

pythonbpf/allocation_pass.py

@@ -5,6 +5,7 @@ from llvmlite import ir
 from dataclasses import dataclass
 from typing import Any
 from pythonbpf.helper import HelperHandlerRegistry
+from .expr import VmlinuxHandlerRegistry
 from pythonbpf.type_deducer import ctypes_to_ir
 
 logger = logging.getLogger(__name__)
@@ -49,6 +50,15 @@ def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
         logger.debug(f"Variable {var_name} already allocated, skipping")
         return
 
+    # When allocating a variable, check if it's a vmlinux struct type
+    if isinstance(stmt.value, ast.Name) and VmlinuxHandlerRegistry.is_vmlinux_struct(
+        stmt.value.id
+    ):
+        # Handle vmlinux struct allocation
+        # This requires more implementation
+        print(stmt.value)
+        pass
+
     # Determine type and allocate based on rval
     if isinstance(rval, ast.Call):
         _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab)

pythonbpf/codegen.py

@@ -5,6 +5,8 @@ from .functions import func_proc
 from .maps import maps_proc
 from .structs import structs_proc
 from .vmlinux_parser import vmlinux_proc
+from pythonbpf.vmlinux_parser.vmlinux_exports_handler import VmlinuxHandler
+from .expr import VmlinuxHandlerRegistry
 from .globals_pass import (
     globals_list_creation,
     globals_processing,
@@ -56,10 +58,13 @@ def processor(source_code, filename, module):
         logger.info(f"Found BPF function/struct: {func_node.name}")
 
     vmlinux_symtab = vmlinux_proc(tree, module)
+    if vmlinux_symtab:
+        handler = VmlinuxHandler.initialize(vmlinux_symtab)
+        VmlinuxHandlerRegistry.set_handler(handler)
+
     populate_global_symbol_table(tree, module)
     license_processing(tree, module)
     globals_processing(tree, module)
-    print("DEBUG:", vmlinux_symtab)
     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)

pythonbpf/expr/__init__.py

@@ -2,6 +2,7 @@ from .expr_pass import eval_expr, handle_expr, get_operand_value
 from .type_normalization import convert_to_bool, get_base_type_and_depth
 from .ir_ops import deref_to_depth
 from .call_registry import CallHandlerRegistry
+from .vmlinux_registry import VmlinuxHandlerRegistry
 
 __all__ = [
     "eval_expr",
@@ -11,4 +12,5 @@ __all__ = [
     "deref_to_depth",
     "get_operand_value",
     "CallHandlerRegistry",
+    "VmlinuxHandlerRegistry",
 ]

pythonbpf/expr/expr_pass.py

@@ -12,6 +12,7 @@ from .type_normalization import (
     get_base_type_and_depth,
     deref_to_depth,
 )
+from .vmlinux_registry import VmlinuxHandlerRegistry
 
 logger: Logger = logging.getLogger(__name__)
 
@@ -27,8 +28,12 @@ def _handle_name_expr(expr: ast.Name, local_sym_tab: Dict, builder: ir.IRBuilder
         val = builder.load(var)
         return val, local_sym_tab[expr.id].ir_type
     else:
-        logger.info(f"Undefined variable {expr.id}")
+        # Check if it's a vmlinux enum/constant
-        return None
+        vmlinux_result = VmlinuxHandlerRegistry.handle_name(expr.id)
+        if vmlinux_result is not None:
+            return vmlinux_result
+
+        raise SyntaxError(f"Undefined variable {expr.id}")
 
 
 def _handle_constant_expr(module, builder, expr: ast.Constant):
@@ -74,6 +79,13 @@ def _handle_attribute_expr(
                 val = builder.load(gep)
                 field_type = metadata.field_type(attr_name)
                 return val, field_type
+
+        # Try vmlinux handler as fallback
+        vmlinux_result = VmlinuxHandlerRegistry.handle_attribute(
+            expr, local_sym_tab, None, builder
+        )
+        if vmlinux_result is not None:
+            return vmlinux_result
     return None
 
 
@@ -130,7 +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))
@@ -332,6 +349,7 @@ def _handle_unary_op(
         neg_one = ir.Constant(ir.IntType(64), -1)
         result = builder.mul(operand, neg_one)
         return result, ir.IntType(64)
+    return None
 
 
 # ============================================================================

pythonbpf/expr/vmlinux_registry.py

@@ -0,0 +1,45 @@
+import ast
+
+
+class VmlinuxHandlerRegistry:
+    """Registry for vmlinux handler operations"""
+
+    _handler = None
+
+    @classmethod
+    def set_handler(cls, handler):
+        """Set the vmlinux handler"""
+        cls._handler = handler
+
+    @classmethod
+    def get_handler(cls):
+        """Get the vmlinux handler"""
+        return cls._handler
+
+    @classmethod
+    def handle_name(cls, name):
+        """Try to handle a name as vmlinux enum/constant"""
+        if cls._handler is None:
+            return None
+        return cls._handler.handle_vmlinux_enum(name)
+
+    @classmethod
+    def handle_attribute(cls, expr, local_sym_tab, module, builder):
+        """Try to handle an attribute access as vmlinux struct field"""
+        if cls._handler is None:
+            return None
+
+        if isinstance(expr.value, ast.Name):
+            var_name = expr.value.id
+            field_name = expr.attr
+            return cls._handler.handle_vmlinux_struct_field(
+                var_name, field_name, module, builder, local_sym_tab
+            )
+        return None
+
+    @classmethod
+    def is_vmlinux_struct(cls, name):
+        """Check if a name refers to a vmlinux struct"""
+        if cls._handler is None:
+            return False
+        return cls._handler.is_vmlinux_struct(name)

pythonbpf/functions/functions_pass.py

@@ -311,7 +311,13 @@ def process_stmt(
 
 
 def process_func_body(
-    module, builder, func_node, func, ret_type, map_sym_tab, structs_sym_tab
+    module,
+    builder,
+    func_node,
+    func,
+    ret_type,
+    map_sym_tab,
+    structs_sym_tab,
 ):
     """Process the body of a bpf function"""
     # TODO: A lot.  We just have print -> bpf_trace_printk for now
@@ -384,7 +390,13 @@ def process_bpf_chunk(func_node, module, return_type, map_sym_tab, structs_sym_t
     builder = ir.IRBuilder(block)
 
     process_func_body(
-        module, builder, func_node, func, ret_type, map_sym_tab, structs_sym_tab
+        module,
+        builder,
+        func_node,
+        func,
+        ret_type,
+        map_sym_tab,
+        structs_sym_tab,
     )
     return func
 

pythonbpf/helper/printk_formatter.py

@@ -3,6 +3,7 @@ import logging
 
 from llvmlite import ir
 from pythonbpf.expr import eval_expr, get_base_type_and_depth, deref_to_depth
+from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
 
 logger = logging.getLogger(__name__)
 
@@ -108,6 +109,16 @@ def _process_name_in_fval(name_node, fmt_parts, exprs, local_sym_tab):
     if local_sym_tab and name_node.id in local_sym_tab:
         _, var_type, tmp = local_sym_tab[name_node.id]
         _populate_fval(var_type, name_node, fmt_parts, exprs)
+    else:
+        # Try to resolve through vmlinux registry if not in local symbol table
+        result = VmlinuxHandlerRegistry.handle_name(name_node.id)
+        if result:
+            val, var_type = result
+            _populate_fval(var_type, name_node, fmt_parts, exprs)
+        else:
+            raise ValueError(
+                f"Variable '{name_node.id}' not found in symbol table or vmlinux"
+            )
 
 
 def _process_attr_in_fval(attr_node, fmt_parts, exprs, local_sym_tab, struct_sym_tab):

pythonbpf/maps/maps_pass.py

@@ -6,6 +6,8 @@ from llvmlite import ir
 from .maps_utils import MapProcessorRegistry
 from .map_types import BPFMapType
 from .map_debug_info import create_map_debug_info, create_ringbuf_debug_info
+from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
+
 
 logger: Logger = logging.getLogger(__name__)
 
@@ -51,7 +53,7 @@ def _parse_map_params(rval, expected_args=None):
     """Parse map parameters from call arguments and keywords."""
 
     params = {}
-
+    handler = VmlinuxHandlerRegistry.get_handler()
     # Parse positional arguments
     if expected_args:
         for i, arg_name in enumerate(expected_args):
@@ -65,7 +67,12 @@ def _parse_map_params(rval, expected_args=None):
     # Parse keyword arguments (override positional)
     for keyword in rval.keywords:
         if isinstance(keyword.value, ast.Name):
-            params[keyword.arg] = keyword.value.id
+            name = keyword.value.id
+            if handler and handler.is_vmlinux_enum(name):
+                result = handler.get_vmlinux_enum_value(name)
+                params[keyword.arg] = result if result is not None else name
+            else:
+                params[keyword.arg] = name
         elif isinstance(keyword.value, ast.Constant):
             params[keyword.arg] = keyword.value.value
 

pythonbpf/vmlinux_parser/vmlinux_exports_handler.py

@@ -0,0 +1,90 @@
+import logging
+from llvmlite import ir
+
+from pythonbpf.vmlinux_parser.assignment_info import AssignmentType
+
+logger = logging.getLogger(__name__)
+
+
+class VmlinuxHandler:
+    """Handler for vmlinux-related operations"""
+
+    _instance = None
+
+    @classmethod
+    def get_instance(cls):
+        """Get the singleton instance"""
+        if cls._instance is None:
+            logger.warning("VmlinuxHandler used before initialization")
+            return None
+        return cls._instance
+
+    @classmethod
+    def initialize(cls, vmlinux_symtab):
+        """Initialize the handler with vmlinux symbol table"""
+        cls._instance = cls(vmlinux_symtab)
+        return cls._instance
+
+    def __init__(self, vmlinux_symtab):
+        """Initialize with vmlinux symbol table"""
+        self.vmlinux_symtab = vmlinux_symtab
+        logger.info(
+            f"VmlinuxHandler initialized with {len(vmlinux_symtab) if vmlinux_symtab else 0} symbols"
+        )
+
+    def is_vmlinux_enum(self, name):
+        """Check if name is a vmlinux enum constant"""
+        return (
+            name in self.vmlinux_symtab
+            and self.vmlinux_symtab[name]["value_type"] == AssignmentType.CONSTANT
+        )
+
+    def is_vmlinux_struct(self, name):
+        """Check if name is a vmlinux struct"""
+        return (
+            name in self.vmlinux_symtab
+            and self.vmlinux_symtab[name]["value_type"] == AssignmentType.STRUCT
+        )
+
+    def handle_vmlinux_enum(self, name):
+        """Handle vmlinux enum constants by returning LLVM IR constants"""
+        if self.is_vmlinux_enum(name):
+            value = self.vmlinux_symtab[name]["value"]
+            logger.info(f"Resolving vmlinux enum {name} = {value}")
+            return ir.Constant(ir.IntType(64), value), ir.IntType(64)
+        return None
+
+    def get_vmlinux_enum_value(self, name):
+        """Handle vmlinux enum constants by returning LLVM IR constants"""
+        if self.is_vmlinux_enum(name):
+            value = self.vmlinux_symtab[name]["value"]
+            logger.info(f"The value of vmlinux enum {name} = {value}")
+            return value
+        return None
+
+    def handle_vmlinux_struct(self, struct_name, module, builder):
+        """Handle vmlinux struct initializations"""
+        if self.is_vmlinux_struct(struct_name):
+            # TODO: Implement core-specific struct handling
+            # This will be more complex and depends on the BTF information
+            logger.info(f"Handling vmlinux struct {struct_name}")
+            # Return struct type and allocated pointer
+            # This is a stub, actual implementation will be more complex
+            return None
+        return None
+
+    def handle_vmlinux_struct_field(
+        self, struct_var_name, field_name, module, builder, local_sym_tab
+    ):
+        """Handle access to vmlinux struct fields"""
+        # Check if it's a variable of vmlinux struct type
+        if struct_var_name in local_sym_tab:
+            var_info = local_sym_tab[struct_var_name]  # noqa: F841
+            # Need to check if this variable is a vmlinux struct
+            # This will depend on how you track vmlinux struct types in your symbol table
+            logger.info(
+                f"Attempting to access field {field_name} of possible vmlinux struct {struct_var_name}"
+            )
+            # Return pointer to field and field type
+            return None
+        return None

tests/passing_tests/vmlinux/simple_struct_test.py

@@ -1,10 +1,26 @@
-from pythonbpf import bpf, section, bpfglobal, compile_to_ir
+import logging
+
+from pythonbpf import bpf, section, bpfglobal, compile_to_ir, map
+from pythonbpf import compile  # noqa: F401
 from vmlinux import TASK_COMM_LEN  # noqa: F401
 from vmlinux import struct_trace_event_raw_sys_enter  # noqa: F401
+from ctypes import c_uint64, c_int32, c_int64
+from pythonbpf.maps import HashMap
 
 # from vmlinux import struct_uinput_device
 # from vmlinux import struct_blk_integrity_iter
-from ctypes import c_int64
+
+
+@bpf
+@map
+def mymap() -> HashMap:
+    return HashMap(key=c_int32, value=c_uint64, max_entries=TASK_COMM_LEN)
+
+
+@bpf
+@map
+def mymap2() -> HashMap:
+    return HashMap(key=c_int32, value=c_uint64, max_entries=18)
 
 
 # Instructions to how to run this program
@@ -16,8 +32,9 @@ from ctypes import c_int64
 @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
-    return c_int64(0)
+    print(f"Hello, World{TASK_COMM_LEN} and {a}")
+    return c_int64(TASK_COMM_LEN + 2)
 
 
 @bpf
@@ -26,4 +43,5 @@ def LICENSE() -> str:
     return "GPL"
 
 
-compile_to_ir("simple_struct_test.py", "simple_struct_test.ll")
+compile_to_ir("simple_struct_test.py", "simple_struct_test.ll", loglevel=logging.DEBUG)
+# compile()