python_exception_handler.h

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#pragma once
 
#include <util/irep/std_code.h>
#include <util/irep/expr.h>
#include <util/message/message.h>
 
#include <nlohmann/json.hpp>
#include <functional>
#include <string>
 
class python_converter;
class type_handler;

class python_exception_handler
{
public:
  explicit python_exception_handler(
    python_converter &converter,
    type_handler &type_handler);
 
  // -----------------------------------------------------------------------
  // Statement converters (called from python_converter::get_block)
  // -----------------------------------------------------------------------

  void get_try_statement(const nlohmann::json &element, codet &block);

  static bool
  body_has_escaping_control_flow(const nlohmann::json &node, bool in_loop);

  static bool
  escape_in_nested_cleanup_scope(const nlohmann::json &node, bool in_loop);

  static bool
  escape_in_nested_cleanup_children(const nlohmann::json &node, bool in_loop);

  void get_raise_statement(const nlohmann::json &element, codet &block);

  void
  get_except_handler_statement(const nlohmann::json &element, codet &block);
 
  // Emit one catch block for a single exception-type node (or null for a bare
  // `except:`); used per type when `except (A, B):` lists a tuple of types.
  void emit_catch_block(
    const nlohmann::json &element,
    const nlohmann::json &type_node,
    codet &block);
 
  // -----------------------------------------------------------------------
  // Assertion helpers (previously python_converter private methods)
  // -----------------------------------------------------------------------

  void handle_list_assertion(
    const nlohmann::json &element,
    const exprt &test,
    code_blockt &block,
    const std::function<void(code_assertt &)> &attach_assert_message);

  void handle_function_call_assertion(
    const nlohmann::json &element,
    const exprt &func_call_expr,
    bool is_negated,
    code_blockt &block,
    const std::function<void(code_assertt &)> &attach_assert_message);
 
  // -----------------------------------------------------------------------
  // Expression helpers (previously function_call_expr / exception_utils)
  // -----------------------------------------------------------------------

  exprt
  gen_exception_raise(const std::string &exc, const std::string &message) const;
 
private:
  python_converter &converter_;
  type_handler &type_handler_;
 
  // ------------------------------------------------------------------
  // Internal helpers
  // ------------------------------------------------------------------

  exprt
  build_builtin_exception(const nlohmann::json &exc, const typet &type) const;

  bool raises_instance_variable(
    const nlohmann::json &exc,
    const std::string &exc_name) const;

  nlohmann::json inject_finally_before_escapes(
    const nlohmann::json &body,
    const nlohmann::json &finalbody,
    bool in_loop);

  void emit_finally_then_escape(
    const nlohmann::json &stmt,
    const nlohmann::json &finalbody,
    nlohmann::json &out);

  unsigned finally_spill_count_ = 0;
 
  exprt make_finally_rethrow_handler(const nlohmann::json &element);
 
  void emit_else_clause(
    const nlohmann::json &element,
    exprt else_block,
    const exprt &no_raise,
    codet &block);

  symbolt create_assert_temp_variable(const locationt &location) const;

  static code_function_callt create_function_call_statement(
    const exprt &func_call_expr,
    const exprt &lhs_var,
    const locationt &location);
};