Refactor allocate_mem

Author: r41k0u

pythonbpf/functions/functions_pass.py

@@ -220,6 +220,203 @@ def process_stmt(
     return did_return
 
 
+def _is_helper_call(call_node):
+    """Check if a call node is a BPF helper function call."""
+    if isinstance(call_node.func, ast.Name):
+        # Exclude print from requiring temps (handles f-strings differently)
+        func_name = call_node.func.id
+        return HelperHandlerRegistry.has_handler(func_name) and func_name != "print"
+
+    elif isinstance(call_node.func, ast.Attribute):
+        return HelperHandlerRegistry.has_handler(call_node.func.attr)
+
+    return False
+
+
+def _handle_if_allocation(
+    module, builder, stmt, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
+):
+    """Recursively handle allocations in if/else branches."""
+    if stmt.body:
+        allocate_mem(
+            module,
+            builder,
+            stmt.body,
+            func,
+            ret_type,
+            map_sym_tab,
+            local_sym_tab,
+            structs_sym_tab,
+        )
+    if stmt.orelse:
+        allocate_mem(
+            module,
+            builder,
+            stmt.orelse,
+            func,
+            ret_type,
+            map_sym_tab,
+            local_sym_tab,
+            structs_sym_tab,
+        )
+
+
+def _handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
+    """Handle memory allocation for assignment statements."""
+
+    # Validate assignment
+    if len(stmt.targets) != 1:
+        logger.warning("Multi-target assignment not supported, skipping allocation")
+        return
+
+    target = stmt.targets[0]
+
+    # Skip non-name targets (e.g., struct field assignments)
+    if isinstance(target, ast.Attribute):
+        logger.debug(f"Struct field assignment to {target.attr}, no allocation needed")
+        return
+
+    if not isinstance(target, ast.Name):
+        logger.warning(f"Unsupported assignment target type: {type(target).__name__}")
+        return
+
+    var_name = target.id
+    rval = stmt.value
+
+    # Skip if already allocated
+    if var_name in local_sym_tab:
+        logger.debug(f"Variable {var_name} already allocated, skipping")
+        return
+
+    # 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)
+    elif isinstance(rval, ast.Constant):
+        _allocate_for_constant(builder, var_name, rval, local_sym_tab)
+    elif isinstance(rval, ast.BinOp):
+        _allocate_for_binop(builder, var_name, local_sym_tab)
+    else:
+        logger.warning(
+            f"Unsupported assignment value type for {var_name}: {type(rval).__name__}"
+        )
+
+
+def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
+    """Allocate memory for variable assigned from a call."""
+
+    if isinstance(rval.func, ast.Name):
+        call_type = rval.func.id
+
+        # C type constructors
+        if call_type in ("c_int32", "c_int64", "c_uint32", "c_uint64"):
+            ir_type = ctypes_to_ir(call_type)
+            var = builder.alloca(ir_type, name=var_name)
+            var.align = ir_type.width // 8
+            local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+            logger.info(f"Pre-allocated {var_name} as {call_type}")
+
+        # Helper functions
+        elif HelperHandlerRegistry.has_handler(call_type):
+            ir_type = ir.IntType(64)  # Assume i64 return type
+            var = builder.alloca(ir_type, name=var_name)
+            var.align = 8
+            local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+            logger.info(f"Pre-allocated {var_name} for helper {call_type}")
+
+        # Deref function
+        elif call_type == "deref":
+            ir_type = ir.IntType(64)  # Assume i64 return type
+            var = builder.alloca(ir_type, name=var_name)
+            var.align = 8
+            local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+            logger.info(f"Pre-allocated {var_name} for deref")
+
+        # Struct constructors
+        elif call_type in structs_sym_tab:
+            struct_info = structs_sym_tab[call_type]
+            var = builder.alloca(struct_info.ir_type, name=var_name)
+            local_sym_tab[var_name] = LocalSymbol(var, struct_info.ir_type, call_type)
+            logger.info(f"Pre-allocated {var_name} for struct {call_type}")
+
+        else:
+            logger.warning(f"Unknown call type for allocation: {call_type}")
+
+    elif isinstance(rval.func, ast.Attribute):
+        # Map method calls - need double allocation for ptr handling
+        _allocate_for_map_method(builder, var_name, local_sym_tab)
+
+    else:
+        logger.warning(f"Unsupported call function type for {var_name}")
+
+
+def _allocate_for_map_method(builder, var_name, local_sym_tab):
+    """Allocate memory for variable assigned from map method (double alloc)."""
+
+    # Main variable (pointer to pointer)
+    ir_type = ir.PointerType(ir.IntType(64))
+    var = builder.alloca(ir_type, name=var_name)
+    local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+
+    # Temporary variable for computed values
+    tmp_ir_type = ir.IntType(64)
+    var_tmp = builder.alloca(tmp_ir_type, name=f"{var_name}_tmp")
+    local_sym_tab[f"{var_name}_tmp"] = LocalSymbol(var_tmp, tmp_ir_type)
+
+    logger.info(f"Pre-allocated {var_name} and {var_name}_tmp for map method")
+
+
+def _allocate_for_constant(builder, var_name, rval, local_sym_tab):
+    """Allocate memory for variable assigned from a constant."""
+
+    if isinstance(rval.value, bool):
+        ir_type = ir.IntType(1)
+        var = builder.alloca(ir_type, name=var_name)
+        var.align = 1
+        local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+        logger.info(f"Pre-allocated {var_name} as bool")
+
+    elif isinstance(rval.value, int):
+        ir_type = ir.IntType(64)
+        var = builder.alloca(ir_type, name=var_name)
+        var.align = 8
+        local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+        logger.info(f"Pre-allocated {var_name} as i64")
+
+    elif isinstance(rval.value, str):
+        ir_type = ir.PointerType(ir.IntType(8))
+        var = builder.alloca(ir_type, name=var_name)
+        var.align = 8
+        local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+        logger.info(f"Pre-allocated {var_name} as string")
+
+    else:
+        logger.warning(
+            f"Unsupported constant type for {var_name}: {type(rval.value).__name__}"
+        )
+
+
+def _allocate_for_binop(builder, var_name, local_sym_tab):
+    """Allocate memory for variable assigned from a binary operation."""
+    ir_type = ir.IntType(64)  # Assume i64 result
+    var = builder.alloca(ir_type, name=var_name)
+    var.align = 8
+    local_sym_tab[var_name] = LocalSymbol(var, ir_type)
+    logger.info(f"Pre-allocated {var_name} for binop result")
+
+
+def _allocate_temp_pool(builder, max_temps, local_sym_tab):
+    """Allocate the temporary scratch space pool for helper arguments."""
+    if max_temps == 0:
+        return
+
+    logger.info(f"Allocating temp pool of {max_temps} variables")
+    for i in range(max_temps):
+        temp_name = f"__helper_temp_{i}"
+        temp_var = builder.alloca(ir.IntType(64), name=temp_name)
+        temp_var.align = 8
+        local_sym_tab[temp_name] = LocalSymbol(temp_var, ir.IntType(64))
+
+
 def count_temps_in_call(call_node, local_sym_tab):
     """Count the number of temporary variables needed for a function call."""
 
@@ -255,7 +452,6 @@ def count_temps_in_call(call_node, local_sym_tab):
 def allocate_mem(
     module, builder, body, func, ret_type, map_sym_tab, local_sym_tab, structs_sym_tab
 ):
-    double_alloc = False
     max_temps_needed = 0
 
     def update_max_temps_for_stmt(stmt):
@@ -276,139 +472,23 @@ def update_max_temps_for_stmt(stmt):
 
     for stmt in body:
         update_max_temps_for_stmt(stmt)
-        has_metadata = False
+
+        # Handle allocations
         if isinstance(stmt, ast.If):
-            if stmt.body:
-                local_sym_tab = allocate_mem(
-                    module,
-                    builder,
-                    stmt.body,
-                    func,
-                    ret_type,
-                    map_sym_tab,
-                    local_sym_tab,
-                    structs_sym_tab,
-                )
-            if stmt.orelse:
-                local_sym_tab = allocate_mem(
-                    module,
-                    builder,
-                    stmt.orelse,
-                    func,
-                    ret_type,
-                    map_sym_tab,
-                    local_sym_tab,
-                    structs_sym_tab,
-                )
+            _handle_if_allocation(
+                module,
+                builder,
+                stmt,
+                func,
+                ret_type,
+                map_sym_tab,
+                local_sym_tab,
+                structs_sym_tab,
+            )
         elif isinstance(stmt, ast.Assign):
-            if len(stmt.targets) != 1:
-                logger.info("Unsupported multiassignment")
-                continue
-            target = stmt.targets[0]
-            if not isinstance(target, ast.Name) and not isinstance(
-                target, ast.Attribute
-            ):
-                logger.info("Unsupported assignment target")
-                continue
-            if isinstance(target, ast.Attribute):
-                logger.info(
-                    f"Struct field {target.attr} assignment, will be handled later"
-                )
-                continue
-            var_name = target.id
-            rval = stmt.value
-            if var_name in local_sym_tab:
-                logger.info(f"Variable {var_name} already allocated")
-                continue
-            if isinstance(rval, ast.Call):
-                if isinstance(rval.func, ast.Name):
-                    call_type = rval.func.id
-                    if call_type in ("c_int32", "c_int64", "c_uint32", "c_uint64"):
-                        ir_type = ctypes_to_ir(call_type)
-                        var = builder.alloca(ir_type, name=var_name)
-                        var.align = ir_type.width // 8
-                        logger.info(
-                            f"Pre-allocated variable {var_name} of type {call_type}"
-                        )
-                    elif HelperHandlerRegistry.has_handler(call_type):
-                        # Assume return type is int64 for now
-                        ir_type = ir.IntType(64)
-                        var = builder.alloca(ir_type, name=var_name)
-                        var.align = ir_type.width // 8
-                        logger.info(f"Pre-allocated variable {var_name} for helper")
-                    elif call_type == "deref" and len(rval.args) == 1:
-                        # Assume return type is int64 for now
-                        ir_type = ir.IntType(64)
-                        var = builder.alloca(ir_type, name=var_name)
-                        var.align = ir_type.width // 8
-                        logger.info(f"Pre-allocated variable {var_name} for deref")
-                    elif call_type in structs_sym_tab:
-                        struct_info = structs_sym_tab[call_type]
-                        ir_type = struct_info.ir_type
-                        var = builder.alloca(ir_type, name=var_name)
-                        has_metadata = True
-                        logger.info(
-                            f"Pre-allocated variable {var_name} for struct {call_type}"
-                        )
-                elif isinstance(rval.func, ast.Attribute):
-                    # Map method call
-                    ir_type = ir.PointerType(ir.IntType(64))
-                    var = builder.alloca(ir_type, name=var_name)
-
-                    # declare an intermediate ptr type for map lookup
-                    tmp_ir_type = ir.IntType(64)
-                    var_tmp = builder.alloca(tmp_ir_type, name=f"{var_name}_tmp")
-                    double_alloc = True
-                    # var.align = ir_type.width // 8
-                    logger.info(
-                        f"Pre-allocated variable {var_name} and {var_name}_tmp for map"
-                    )
-                else:
-                    logger.info("Unsupported assignment call function type")
-                    continue
-            elif isinstance(rval, ast.Constant):
-                if isinstance(rval.value, bool):
-                    ir_type = ir.IntType(1)
-                    var = builder.alloca(ir_type, name=var_name)
-                    var.align = 1
-                    logger.info(f"Pre-allocated variable {var_name} of type c_bool")
-                elif isinstance(rval.value, int):
-                    # Assume c_int64 for now
-                    ir_type = ir.IntType(64)
-                    var = builder.alloca(ir_type, name=var_name)
-                    var.align = ir_type.width // 8
-                    logger.info(f"Pre-allocated variable {var_name} of type c_int64")
-                elif isinstance(rval.value, str):
-                    ir_type = ir.PointerType(ir.IntType(8))
-                    var = builder.alloca(ir_type, name=var_name)
-                    var.align = 8
-                    logger.info(f"Pre-allocated variable {var_name} of type string")
-                else:
-                    logger.info("Unsupported constant type")
-                    continue
-            elif isinstance(rval, ast.BinOp):
-                # Assume c_int64 for now
-                ir_type = ir.IntType(64)
-                var = builder.alloca(ir_type, name=var_name)
-                var.align = ir_type.width // 8
-                logger.info(f"Pre-allocated variable {var_name} of type c_int64")
-            else:
-                logger.info("Unsupported assignment value type")
-                continue
-
-            if has_metadata:
-                local_sym_tab[var_name] = LocalSymbol(var, ir_type, call_type)
-            else:
-                local_sym_tab[var_name] = LocalSymbol(var, ir_type)
-
-            if double_alloc:
-                local_sym_tab[f"{var_name}_tmp"] = LocalSymbol(var_tmp, tmp_ir_type)
-
-    logger.info(f"Temporary scratch space needed for calls: {max_temps_needed}")
-    for i in range(max_temps_needed):
-        temp_var = builder.alloca(ir.IntType(64), name=f"__helper_temp_{i}")
-        temp_var.align = 8
-        local_sym_tab[f"__helper_temp_{i}"] = LocalSymbol(temp_var, ir.IntType(64))
+            _handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab)
+
+    _allocate_temp_pool(builder, max_temps_needed, local_sym_tab)
 
     return local_sym_tab