view libinterp/parse-tree/pt-pr-code.h @ 29724:c19f8cbe0fd5

initial implementation of parsing for arguments validaton block (bug #59405) This change allows parsing of arguments validation blocks. Octave should now accept the arguments block syntax in a mostly Matlab compatible way. Multiple argument blocks are allowed. All arguments blocks must appear before any other exectuable statements in a function. Similar to "methods", "properties", etc., "arguments" is defined as a keyword in the octave.gperf file so that converting "arguments" to the ARGUMENTS token in the lexer and parser is simplified but it is not really treated as a reserved keyword in the language. One known problem with the current approach is that function [...] = f (...) arguments = 13; ... end will result in a parse error. A simple workaround is to place another statement (that is not an arguments block) ahead of the "arguments = ..." line in the function. Fixing this problem generally might require a different parsing method that allows a different type of lookahead than we currently use. NOTE: arguments blocks do not currently perform any actions. Since they may provide default values and/or transform arguments to different types or values, ignoring the arguments block can lead to incorrect results. Octave also currently allows arguments blocks in nested functions though they should be rejected. Special treatment of "arguments" and "endarguments" may be disabled by defining the macro DISABLE_ARGUMENTS_VALIDATION_BLOCK. With this macro defined, Octave's lexer will never return the ARGUMENTS token, so the parser will fail to parse these program elements and the behavior should be the same as prior to this change. * pt-args-block.h, pt-args-block.cc: New files. * libinterp/parse-tree/module.mk: Update. * lex.h, lex.ll (lexical_feedback::m_arguments_is_keyword): New member variable. (lexical_feedback::reset): Reset m_arguments_is_keyword to false. (iskeyword, Fiskeyword): Also handle "arguments" as a special case. (base_lexer::make_keyword_token): Handle arguments and endarguments. * parse.h, oct-parse.yy (base_parser::make_arguments_block, base_parser::make_args_attribute_list, base_parser::make_arg_validation, base_parser::make_args_validation_list, base_parser::append_args_validation_list, base_parser::make_arg_size_spec, base_parser::make_arg_validation_fcns): New functions. (function_body, at_first_executable_stmt, function_body1, arguments_block, arguments_beg, args_attr_list, args_validation_list, arg_validation, size_spec, class_name, validation_fcns, default_value): New non-terminals. (ARGUMENTS): New token. (function): Use new function_body and function_body1 non-terminals to accept arguments blocks, but only at the beginning of a function. (fcn_name): Set lexer.m_arguments_is_keyword to true after parsing function name. (param_list_beg): Set lexer.m_arguments_is_keyword to false while parsing function parameter list. (param_list_beg): Reset lexer.m_arguments_is_keyword to true after parsing function parameter list. (tree_arguments_block_type, tree_args_block_attribute_list_type, tree_args_block_validation_list_type, tree_arg_size_spec_type, tree_arg_validation_type, tree_arg_validation_fcns_type): New non-terminal types. Also declare %destructors for them. * octave.gperf (octave_kw_id): New IDs, arguments_kw and endarguments_kw. Provide entries for arguments and endarguments keywords. * pt-all.h: Include pt-args-block.h. * pt-bp.h, pt-bp.cc (tree_breakpoint::visit_arguments_block, tree_breakpoint::visit_args_block_attribute_list, tree_breakpoint::visit_args_block_validation_list, tree_breakpoint::visit_arg_validation, tree_breakpoint::visit_arg_size_spec, tree_breakpoint::visit_arg_validation_fcns): New virtual functions for arguments block elements. * pt-eval.h, pt-eval.cc (tree_evaluator::visit_arguments_block, tree_evaluator::visit_args_block_attribute_list, tree_evaluator::visit_args_block_validation_list, tree_evaluator::visit_arg_validation, tree_evaluator::visit_arg_size_spec, tree_evaluator::visit_arg_validation_fcns): New virtual functions for arguments block elements. * pt-pr-code.h, pt-pr-code.cc (tree_print_code::visit_arguments_block, tree_print_code::visit_args_block_attribute_list, tree_print_code::visit_args_block_validation_list, tree_print_code::visit_arg_validation, tree_print_code::visit_arg_size_spec, tree_print_code::visit_arg_validation_fcns): New virtual functions for arguments block elements. * pt-walk.h, pt-walk.cc (tree_walker::visit_arguments_block, tree_walker::visit_args_block_attribute_list, tree_walker::visit_args_block_validation_list, tree_walker::visit_arg_validation, tree_walker::visit_arg_size_spec, tree_walker::visit_arg_validation_fcns): New virtual functions for arguments block elements. * token.h (end_tok_type): New type, arguments_end.
author John W. Eaton <jwe@octave.org>
date Tue, 01 Jun 2021 13:34:57 -0400
parents 7854d5752dd2
children 796f54d4ddbf
line wrap: on
line source

////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1996-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_pt_pr_code_h)
#define octave_pt_pr_code_h 1

#include "octave-config.h"

#include <stack>
#include <string>

#include "pt-walk.h"

namespace octave
{
  class comment_elt;
  class comment_list;
  class tree_decl_command;
  class tree_expression;

  // How to print the code that the parse trees represent.

  class tree_print_code : public tree_walker
  {
  public:

    tree_print_code (std::ostream& os_arg,
                     const std::string& pfx = "",
                     bool pr_orig_txt = true)
      : m_os (os_arg), m_prefix (pfx), m_nesting (),
        m_print_original_text (pr_orig_txt),
        m_curr_print_indent_level (0), m_beginning_of_line (true),
        m_suppress_newlines (0)
    {
      // For "none".
      m_nesting.push ('n');
    }

    // No copying!

    tree_print_code (const tree_print_code&) = delete;

    tree_print_code& operator = (const tree_print_code&) = delete;

    ~tree_print_code (void) = default;

    void visit_anon_fcn_handle (tree_anon_fcn_handle&);

    void visit_argument_list (tree_argument_list&);

    void visit_arguments_block (tree_arguments_block&);

    void visit_args_block_attribute_list (tree_args_block_attribute_list&);

    void visit_args_block_validation_list (tree_args_block_validation_list&);

    void visit_arg_validation (tree_arg_validation&);

    void visit_arg_size_spec (tree_arg_size_spec&);

    void visit_arg_validation_fcns (tree_arg_validation_fcns&);

    void visit_binary_expression (tree_binary_expression&);

    void visit_break_command (tree_break_command&);

    void visit_colon_expression (tree_colon_expression&);

    void visit_continue_command (tree_continue_command&);

    void visit_decl_command (tree_decl_command&);

    void visit_decl_init_list (tree_decl_init_list&);

    void visit_decl_elt (tree_decl_elt&);

    void visit_simple_for_command (tree_simple_for_command&);

    void visit_complex_for_command (tree_complex_for_command&);

    void visit_spmd_command (tree_spmd_command&);

    void visit_octave_user_script (octave_user_script&);

    void visit_octave_user_function (octave_user_function&);

    void visit_octave_user_function_header (octave_user_function&);

    void visit_octave_user_function_trailer (octave_user_function&);

    void visit_function_def (tree_function_def&);

    void visit_identifier (tree_identifier&);

    void visit_if_clause (tree_if_clause&);

    void visit_if_command (tree_if_command&);

    void visit_if_command_list (tree_if_command_list&);

    void visit_index_expression (tree_index_expression&);

    void visit_matrix (tree_matrix&);

    void visit_cell (tree_cell&);

    void visit_multi_assignment (tree_multi_assignment&);

    void visit_no_op_command (tree_no_op_command&);

    void visit_constant (tree_constant&);

    void visit_fcn_handle (tree_fcn_handle&);

    void visit_parameter_list (tree_parameter_list&);

    void visit_postfix_expression (tree_postfix_expression&);

    void visit_prefix_expression (tree_prefix_expression&);

    void visit_return_command (tree_return_command&);

    void visit_simple_assignment (tree_simple_assignment&);

    void visit_statement (tree_statement&);

    void visit_statement_list (tree_statement_list&);

    void visit_switch_case (tree_switch_case&);

    void visit_switch_command (tree_switch_command&);

    void visit_try_catch_command (tree_try_catch_command&);

    void visit_unwind_protect_command (tree_unwind_protect_command&);

    void visit_while_command (tree_while_command&);

    void visit_do_until_command (tree_do_until_command&);

    void visit_superclass_ref (tree_superclass_ref&);

    void visit_metaclass_query (tree_metaclass_query&);

    void print_fcn_handle_body (tree_expression *);

  private:

    std::ostream& m_os;

    std::string m_prefix;

    std::stack<char> m_nesting;

    bool m_print_original_text;

    // Current indentation.
    int m_curr_print_indent_level;

    // TRUE means we are at the beginning of a line.
    bool m_beginning_of_line;

    // Nonzero means we are not printing newlines and indenting.
    int m_suppress_newlines;

    void reset_indent_level (void) { m_curr_print_indent_level = 0; }

    void increment_indent_level (void) { m_curr_print_indent_level += 2; }

    void decrement_indent_level (void) { m_curr_print_indent_level -= 2; }

    void newline (const char *alt_txt = ", ");

    void indent (void);

    void reset (void);

    void print_parens (const tree_expression& expr, const char *txt);

    void print_comment_list (comment_list *comment_list);

    void print_comment_elt (const comment_elt& comment_elt);

    void print_indented_comment (comment_list *comment_list);

    // Must create with an output stream!

    tree_print_code (void);
  };
}

#endif