Add docstrings to core modules and helper functions

Co-authored-by: varun-r-mallya <100590632+varun-r-mallya@users.noreply.github.com>

pythonbpf/globals_pass.py

@@ -12,6 +12,16 @@ global_sym_tab = []
 
 
 def populate_global_symbol_table(tree, module: ir.Module):
+    """
+    Populate the global symbol table with BPF functions, maps, and globals.
+    
+    Args:
+        tree: The Python AST to scan for global symbols
+        module: The LLVM IR module (not used in current implementation)
+    
+    Returns:
+        False (legacy return value)
+    """
     for node in tree.body:
         if isinstance(node, ast.FunctionDef):
             for dec in node.decorator_list:
@@ -33,6 +43,17 @@ def populate_global_symbol_table(tree, module: ir.Module):
 
 
 def emit_global(module: ir.Module, node, name):
+    """
+    Emit a BPF global variable into the LLVM IR module.
+    
+    Args:
+        module: The LLVM IR module to add the global variable to
+        node: The AST function node containing the global definition
+        name: The name of the global variable
+    
+    Returns:
+        The created global variable
+    """
     logger.info(f"global identifier {name} processing")
     # deduce LLVM type from the annotated return
     if not isinstance(node.returns, ast.Name):
@@ -117,7 +138,11 @@ def globals_processing(tree, module):
 
 def emit_llvm_compiler_used(module: ir.Module, names: list[str]):
     """
-    Emit the @llvm.compiler.used global given a list of function/global names.
+    Emit the @llvm.compiler.used global to prevent LLVM from optimizing away symbols.
+    
+    Args:
+        module: The LLVM IR module to add the compiler.used metadata to
+        names: List of function/global names that must be preserved
     """
     ptr_ty = ir.PointerType()
     used_array_ty = ir.ArrayType(ptr_ty, len(names))
@@ -138,6 +163,13 @@ def emit_llvm_compiler_used(module: ir.Module, names: list[str]):
 
 
 def globals_list_creation(tree, module: ir.Module):
+    """
+    Collect all BPF symbols and emit @llvm.compiler.used metadata.
+    
+    Args:
+        tree: The Python AST to scan for symbols
+        module: The LLVM IR module to add metadata to
+    """
     collected = ["LICENSE"]
 
     for node in tree.body: