format chore

Signed-off-by: varun-r-mallya <varunrmallya@gmail.com>

.pre-commit-config.yaml

@@ -21,7 +21,7 @@ ci:
 repos:
 # Standard hooks
 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v6.0.0
+  rev: v4.6.0
   hooks:
   - id: check-added-large-files
   - id: check-case-conflict
@@ -36,7 +36,7 @@ repos:
   - id: trailing-whitespace
 
 - repo: https://github.com/astral-sh/ruff-pre-commit
-  rev: "v0.13.2"
+  rev: "v0.4.2"
   hooks:
     - id: ruff
       args: ["--fix", "--show-fixes"]
@@ -45,7 +45,7 @@ repos:
 
 # Checking static types
 - repo: https://github.com/pre-commit/mirrors-mypy
-  rev: "v1.18.2"
+  rev: "v1.10.0"
   hooks:
     - id: mypy
       exclude: ^(tests)|^(examples)

TODO.md

@@ -1,6 +1,7 @@
 ## Short term
 
 - Implement enough functionality to port the BCC tutorial examples in PythonBPF
+- Static Typing
 - Add all maps
 - XDP support in pylibbpf
 - ringbuf support

examples/clone-matplotlib.ipynb

@@ -12,7 +12,7 @@
     "from pythonbpf import bpf, map, section, bpfglobal, BPF\n",
     "from pythonbpf.helper import pid\n",
     "from pythonbpf.maps import HashMap\n",
-    "from pylibbpf import BpfMap\n",
+    "from pylibbpf import *\n",
     "from ctypes import c_void_p, c_int64, c_uint64, c_int32\n",
     "import matplotlib.pyplot as plt"
    ]

pythonbpf/codegen.py

@@ -4,7 +4,11 @@ from .license_pass import license_processing
 from .functions_pass import func_proc
 from .maps import maps_proc
 from .structs import structs_proc
-from .globals_pass import globals_processing
+from .globals_pass import (
+    globals_list_creation,
+    globals_processing,
+    populate_global_symbol_table,
+)
 from .debuginfo import DW_LANG_C11, DwarfBehaviorEnum, DebugInfoGenerator
 import os
 import subprocess
@@ -40,12 +44,15 @@ def processor(source_code, filename, module):
     for func_node in bpf_chunks:
         logger.info(f"Found BPF function/struct: {func_node.name}")
 
+    populate_global_symbol_table(tree, module)
+    license_processing(tree, 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)
 
-    license_processing(tree, module)
-    globals_processing(tree, module)
+    globals_list_creation(tree, module)
 
 
 def compile_to_ir(filename: str, output: str, loglevel=logging.WARNING):

pythonbpf/functions_pass.py

@@ -146,7 +146,8 @@ def handle_assign(
                     local_sym_tab[var_name].var,
                 )
                 logger.info(
-                    f"Assigned {call_type} constant {rval.args[0].value} to {var_name}"
+                    f"Assigned {call_type} constant "
+                    f"{rval.args[0].value} to {var_name}"
                 )
             elif HelperHandlerRegistry.has_handler(call_type):
                 # var = builder.alloca(ir.IntType(64), name=var_name)
@@ -482,7 +483,8 @@ def allocate_mem(
                         var = builder.alloca(ir_type, name=var_name)
                         has_metadata = True
                         logger.info(
-                            f"Pre-allocated variable {var_name} for struct {call_type}"
+                            f"Pre-allocated variable {var_name} "
+                            f"for struct {call_type}"
                         )
                 elif isinstance(rval.func, ast.Attribute):
                     ir_type = ir.PointerType(ir.IntType(64))

pythonbpf/globals_pass.py

@@ -1,8 +1,121 @@
 from llvmlite import ir
 import ast
 
+from logging import Logger
+import logging
+from .type_deducer import ctypes_to_ir
 
-def emit_globals(module: ir.Module, names: list[str]):
+logger: Logger = logging.getLogger(__name__)
+
+# TODO: this is going to be a huge fuck of a headache in the future.
+global_sym_tab = []
+
+
+def populate_global_symbol_table(tree, module: ir.Module):
+    for node in tree.body:
+        if isinstance(node, ast.FunctionDef):
+            for dec in node.decorator_list:
+                if (
+                    isinstance(dec, ast.Call)
+                    and isinstance(dec.func, ast.Name)
+                    and dec.func.id == "section"
+                    and len(dec.args) == 1
+                    and isinstance(dec.args[0], ast.Constant)
+                    and isinstance(dec.args[0].value, str)
+                ):
+                    global_sym_tab.append(node)
+                elif isinstance(dec, ast.Name) and dec.id == "bpfglobal":
+                    global_sym_tab.append(node)
+
+                elif isinstance(dec, ast.Name) and dec.id == "map":
+                    global_sym_tab.append(node)
+    return False
+
+
+def emit_global(module: ir.Module, node, name):
+    logger.info(f"global identifier {name} processing")
+    # deduce LLVM type from the annotated return
+    if not isinstance(node.returns, ast.Name):
+        raise ValueError(f"Unsupported return annotation {ast.dump(node.returns)}")
+    ty = ctypes_to_ir(node.returns.id)
+
+    # extract the return expression
+    # TODO: turn this return extractor into a generic function I can use everywhere.
+    ret_stmt = node.body[0]
+    if not isinstance(ret_stmt, ast.Return) or ret_stmt.value is None:
+        raise ValueError(f"Global '{name}' has no valid return")
+
+    init_val = ret_stmt.value
+
+    # simple constant like "return 0"
+    if isinstance(init_val, ast.Constant):
+        llvm_init = ir.Constant(ty, init_val.value)
+
+    # variable reference like "return SOME_CONST"
+    elif isinstance(init_val, ast.Name):
+        # need symbol resolution here, stub as 0 for now
+        raise ValueError(f"Name reference {init_val.id} not yet supported")
+
+    # constructor call like "return c_int64(0)" or dataclass(...)
+    elif isinstance(init_val, ast.Call):
+        if len(init_val.args) >= 1 and isinstance(init_val.args[0], ast.Constant):
+            llvm_init = ir.Constant(ty, init_val.args[0].value)
+        else:
+            logger.info("Defaulting to zero as no constant argument found")
+            llvm_init = ir.Constant(ty, 0)
+    else:
+        raise ValueError(f"Unsupported return expr {ast.dump(init_val)}")
+
+    gvar = ir.GlobalVariable(module, ty, name=name)
+    gvar.initializer = llvm_init
+    gvar.align = 8
+    gvar.linkage = "dso_local"
+    gvar.global_constant = False
+    return gvar
+
+
+def globals_processing(tree, module):
+    """Process stuff decorated with @bpf and @bpfglobal except license and return the section name"""
+    globals_sym_tab = []
+
+    for node in tree.body:
+        # Skip non-assignment and non-function nodes
+        if not (isinstance(node, ast.FunctionDef)):
+            continue
+
+        # Get the name based on node type
+        if isinstance(node, ast.FunctionDef):
+            name = node.name
+        else:
+            continue
+
+        # Check for duplicate names
+        if name in globals_sym_tab:
+            raise SyntaxError(f"ERROR: Global name '{name}' previously defined")
+        else:
+            globals_sym_tab.append(name)
+
+        if isinstance(node, ast.FunctionDef) and node.name != "LICENSE":
+            decorators = [
+                dec.id for dec in node.decorator_list if isinstance(dec, ast.Name)
+            ]
+            if "bpf" in decorators and "bpfglobal" in decorators:
+                if (
+                    len(node.body) == 1
+                    and isinstance(node.body[0], ast.Return)
+                    and node.body[0].value is not None
+                    and isinstance(
+                        node.body[0].value, (ast.Constant, ast.Name, ast.Call)
+                    )
+                ):
+                    emit_global(module, node, name)
+                else:
+                    raise SyntaxError(f"ERROR: Invalid syntax for {name} global")
+
+    return None
+
+
+def emit_llvm_compiler_used(module: ir.Module, names: list[str]):
     """
     Emit the @llvm.compiler.used global given a list of function/global names.
     """
@@ -24,7 +137,7 @@ def emit_globals(module: ir.Module, names: list[str]):
     gv.section = "llvm.metadata"
 
 
-def globals_processing(tree, module: ir.Module):
+def globals_list_creation(tree, module: ir.Module):
     collected = ["LICENSE"]
 
     for node in tree.body:
@@ -40,10 +153,11 @@ def globals_processing(tree, module: ir.Module):
                 ):
                     collected.append(node.name)
 
-                elif isinstance(dec, ast.Name) and dec.id == "bpfglobal":
-                    collected.append(node.name)
+                # NOTE: all globals other than
+                # elif isinstance(dec, ast.Name) and dec.id == "bpfglobal":
+                #     collected.append(node.name)
 
                 elif isinstance(dec, ast.Name) and dec.id == "map":
                     collected.append(node.name)
 
-    emit_globals(module, collected)
+    emit_llvm_compiler_used(module, collected)

pythonbpf/helper/bpf_helper_handler.py

@@ -62,7 +62,7 @@ def bpf_map_lookup_elem_emitter(
     """
     if not call.args or len(call.args) != 1:
         raise ValueError(
-            f"Map lookup expects exactly one argument (key), got {len(call.args)}"
+            "Map lookup expects exactly one argument (key), got " f"{len(call.args)}"
         )
     key_ptr = get_or_create_ptr_from_arg(call.args[0], builder, local_sym_tab)
     map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
@@ -145,7 +145,8 @@ def bpf_map_update_elem_emitter(
     """
     if not call.args or len(call.args) < 2 or len(call.args) > 3:
         raise ValueError(
-            f"Map update expects 2 or 3 args (key, value, flags), got {len(call.args)}"
+            "Map update expects 2 or 3 args (key, value, flags), "
+            f"got {len(call.args)}"
         )
 
     key_arg = call.args[0]
@@ -195,7 +196,7 @@ def bpf_map_delete_elem_emitter(
     """
     if not call.args or len(call.args) != 1:
         raise ValueError(
-            f"Map delete expects exactly one argument (key), got {len(call.args)}"
+            "Map delete expects exactly one argument (key), got " f"{len(call.args)}"
         )
     key_ptr = get_or_create_ptr_from_arg(call.args[0], builder, local_sym_tab)
     map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
@@ -254,7 +255,7 @@ def bpf_perf_event_output_handler(
 ):
     if len(call.args) != 1:
         raise ValueError(
-            f"Perf event output expects exactly one argument, got {len(call.args)}"
+            "Perf event output expects exactly one argument, " f"got {len(call.args)}"
         )
     data_arg = call.args[0]
     ctx_ptr = func.args[0]  # First argument to the function is ctx

pythonbpf/helper/helper_utils.py

@@ -270,7 +270,7 @@ def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_ta
                 val = builder.sext(val, ir.IntType(64))
         else:
             logger.warning(
-                "Only int and ptr supported in bpf_printk args. Others default to 0."
+                "Only int and ptr supported in bpf_printk args. " "Others default to 0."
             )
             val = ir.Constant(ir.IntType(64), 0)
         return val

pythonbpf/maps/maps_pass.py

@@ -278,7 +278,9 @@ def process_bpf_map(func_node, module):
         if handler:
             return handler(map_name, rval, module)
         else:
-            logger.warning(f"Unknown map type {rval.func.id}, defaulting to HashMap")
+            logger.warning(
+                f"Unknown map type " f"{rval.func.id}, defaulting to HashMap"
+            )
             return process_hash_map(map_name, rval, module)
     else:
         raise ValueError("Function under @map must return a map")

tests/c-form/globals.bpf.c

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <linux/types.h>
+
+struct test_struct {
+    __u64 a;
+    __u64 b;
+};
+
+struct test_struct w = {};
+volatile __u64 prev_time = 0;
+
+SEC("tracepoint/syscalls/sys_enter_execve")
+int trace_execve(void *ctx)
+{
+    bpf_printk("previous %ul now %ul", w.b, w.a);
+    __u64 ts = bpf_ktime_get_ns();
+    bpf_printk("prev %ul now %ul", prev_time, ts);
+    w.a = ts;
+    w.b = prev_time;
+    prev_time = ts;
+    return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";

tests/failing_tests/globals.py

@@ -0,0 +1,101 @@
+import logging
+
+from pythonbpf import compile, bpf, section, bpfglobal, compile_to_ir
+from ctypes import c_void_p, c_int64, c_int32
+
+@bpf
+@bpfglobal
+def somevalue() -> c_int32:
+    return c_int32(42)
+
+@bpf
+@bpfglobal
+def somevalue2() -> c_int64:
+    return c_int64(69)
+
+@bpf
+@bpfglobal
+def somevalue1() -> c_int32:
+    return c_int32(42)
+
+
+# --- Passing examples ---
+
+# Simple constant return
+@bpf
+@bpfglobal
+def g1() -> c_int64:
+    return c_int64(42)
+
+# Constructor with one constant argument
+@bpf
+@bpfglobal
+def g2() -> c_int64:
+    return c_int64(69)
+
+
+# --- Failing examples ---
+
+# No return annotation
+# @bpf
+# @bpfglobal
+# def g3():
+#     return 42
+
+# Return annotation is complex
+# @bpf
+# @bpfglobal
+# def g4() -> List[int]:
+#     return []
+
+# # Return is missing
+# @bpf
+# @bpfglobal
+# def g5() -> c_int64:
+#     pass
+
+# # Return is a variable reference
+# #TODO: maybe fix this sometime later. It defaults to 0
+# CONST = 5
+# @bpf
+# @bpfglobal
+# def g6() -> c_int64:
+#     return c_int64(CONST)
+
+# Constructor with multiple args
+#TODO: this is not working. should it work ?
+@bpf
+@bpfglobal
+def g7() -> c_int64:
+    return c_int64(1)
+
+# Dataclass call
+#TODO: fails with dataclass
+# @dataclass
+# class Point:
+#     x: c_int64
+#     y: c_int64
+
+# @bpf
+# @bpfglobal
+# def g8() -> Point:
+#     return Point(1, 2)
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def sometag(ctx: c_void_p) -> c_int64:
+    print("test")
+    global somevalue
+    somevalue = 2
+    print(f"{somevalue}")
+    return c_int64(1)
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile_to_ir("globals.py", "globals.ll", loglevel=logging.INFO)
+compile()

tests/failing_tests/undeclared_values.py

@@ -0,0 +1,21 @@
+import logging
+
+from pythonbpf import compile, bpf, section, bpfglobal, compile_to_ir
+from ctypes import c_void_p, c_int64
+
+# This should not pass as somevalue is not declared at all.
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def sometag(ctx: c_void_p) -> c_int64:
+    print("test")
+    print(f"{somevalue}")  # noqa: F821
+    return c_int64(1)
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile_to_ir("globals.py", "globals.ll", loglevel=logging.INFO)
+compile()