parse.h

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/*

Copyright (C) 1993-2017 John W. Eaton

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
<http://www.gnu.org/licenses/>.

*/

#if ! defined (octave_parse_h)
#define octave_parse_h 1

#include "octave-config.h"

#include <cstdio>

#include <string>

#include <stack>
#include <vector>
#include <map>

#include "lex.h"
#include "symtab.h"
#include "token.h"

class octave_comment_list;
class octave_function;
class octave_user_function;
class tree;
class tree_anon_fcn_handle;
class tree_argument_list;
class tree_array_list;
class tree_cell;
class tree_classdef;
class tree_classdef_attribute_list;
class tree_classdef_body;
class tree_classdef_enum_block;
class tree_classdef_enum_list;
class tree_classdef_events_block;
class tree_classdef_events_list;
class tree_classdef_methods_block;
class tree_classdef_methods_list;
class tree_classdef_properties_block;
class tree_classdef_property_list;
class tree_classdef_superclass_list;
class tree_colon_expression;
class tree_command;
class tree_constant;
class tree_decl_command;
class tree_decl_init_list;
class tree_expression;
class tree_fcn_handle;
class tree_funcall;
class tree_function_def;
class tree_identifier;
class tree_if_clause;
class tree_if_command;
class tree_if_command_list;
class tree_index_expression;
class tree_matrix;
class tree_matrix;
class tree_parameter_list;
class tree_statement;
class tree_statement_list;
class tree_statement_listtree_statement;
class tree_switch_case;
class tree_switch_case_list;
class tree_switch_command;

#include "ovl.h"

// Nonzero means print parser debugging info (-d).
extern int octave_debug;

// TRUE means we printed messages about reading startup files.
extern bool reading_startup_message_printed;

extern OCTINTERP_API std::string
get_help_from_file (const std::string& nm, bool& symbol_found,
                    std::string& file);

extern OCTINTERP_API std::string
get_help_from_file (const std::string& nm, bool& symbol_found);

extern OCTINTERP_API std::string lookup_autoload (const std::string& nm);

extern OCTINTERP_API string_vector autoloaded_functions (void);

extern OCTINTERP_API string_vector
reverse_lookup_autoload (const std::string& nm);

extern OCTINTERP_API octave_function *
load_fcn_from_file (const std::string& file_name,
                    const std::string& dir_name = "",
                    const std::string& dispatch_type = "",
                    const std::string& package_name = "",
                    const std::string& fcn_name = "",
                    bool autoload = false);

extern OCTINTERP_API void
source_file (const std::string& file_name,
             const std::string& context = "",
             bool verbose = false, bool require_file = true,
             const std::string& warn_for = "");

extern OCTINTERP_API octave_value_list
feval (const std::string& name,
       const octave_value_list& args = octave_value_list (),
       int nargout = 0);

extern OCTINTERP_API octave_value_list
feval (octave_function *fcn,
       const octave_value_list& args = octave_value_list (),
       int nargout = 0);

extern OCTINTERP_API octave_value_list
feval (const octave_value_list& args, int nargout = 0);

extern OCTINTERP_API octave_value_list
eval_string (const std::string&, bool silent, int& parse_status, int nargout);

extern OCTINTERP_API octave_value
eval_string (const std::string&, bool silent, int& parse_status);

extern OCTINTERP_API void cleanup_statement_list (tree_statement_list **lst);

namespace octave
{
  // Global access to currently active lexer.
  // FIXME: to be removed after more parser+lexer refactoring.
  extern base_lexer *LEXER;

  class
  base_parser
  {
  public:

    base_parser (base_lexer& lxr);

    ~base_parser (void);

    void reset (void);

    // Error mesages for mismatched end tokens.
    void end_token_error (token *tok, token::end_tok_type expected);

    // Check to see that end tokens are properly matched.
    bool end_token_ok (token *tok, token::end_tok_type expected);

    // Maybe print a warning if an assignment expression is used as the
    // test in a logical expression.
    void maybe_warn_assign_as_truth_value (tree_expression *expr);

    // Maybe print a warning about switch labels that aren't constants.
    void maybe_warn_variable_switch_label (tree_expression *expr);

    // Finish building a range.
    tree_expression *finish_colon_expression (tree_colon_expression *e);

    // Build a constant.
    tree_constant *make_constant (int op, token *tok_val);

    // Build a function handle.
    tree_fcn_handle *make_fcn_handle (token *tok_val);

    // Build an anonymous function handle.
    tree_anon_fcn_handle *
    make_anon_fcn_handle (tree_parameter_list *param_list, tree_statement *stmt);

    // Build a binary expression.
    tree_expression *
    make_binary_op (int op, tree_expression *op1, token *tok_val,
                    tree_expression *op2);

    // Build a boolean expression.
    tree_expression *
    make_boolean_op (int op, tree_expression *op1, token *tok_val,
                     tree_expression *op2);

    // Build a prefix expression.
    tree_expression *
    make_prefix_op (int op, tree_expression *op1, token *tok_val);

    // Build a postfix expression.
    tree_expression *
    make_postfix_op (int op, tree_expression *op1, token *tok_val);

    // Build an unwind-protect command.
    tree_command *
    make_unwind_command (token *unwind_tok, tree_statement_list *body,
                         tree_statement_list *cleanup, token *end_tok,
                         octave_comment_list *lc, octave_comment_list *mc);

    // Build a try-catch command.
    tree_command *
    make_try_command (token *try_tok, tree_statement_list *body,
                      char catch_sep, tree_statement_list *cleanup,
                      token *end_tok, octave_comment_list *lc,
                      octave_comment_list *mc);

    // Build a while command.
    tree_command *
    make_while_command (token *while_tok, tree_expression *expr,
                        tree_statement_list *body, token *end_tok,
                        octave_comment_list *lc);

    // Build a do-until command.
    tree_command *
    make_do_until_command (token *until_tok, tree_statement_list *body,
                           tree_expression *expr, octave_comment_list *lc);

    // Build a for command.
    tree_command *
    make_for_command (int tok_id, token *for_tok, tree_argument_list *lhs,
                      tree_expression *expr, tree_expression *maxproc,
                      tree_statement_list *body, token *end_tok,
                      octave_comment_list *lc);

    // Build a break command.
    tree_command *make_break_command (token *break_tok);

    // Build a continue command.
    tree_command *make_continue_command (token *continue_tok);

    // Build a return command.
    tree_command *make_return_command (token *return_tok);

    // Start an if command.
    tree_if_command_list *
    start_if_command (tree_expression *expr, tree_statement_list *list);

    // Finish an if command.
    tree_if_command *
    finish_if_command (token *if_tok, tree_if_command_list *list,
                       token *end_tok, octave_comment_list *lc);

    // Build an elseif clause.
    tree_if_clause *
    make_elseif_clause (token *elseif_tok, tree_expression *expr,
                        tree_statement_list *list, octave_comment_list *lc);

    // Finish a switch command.
    tree_switch_command *
    finish_switch_command (token *switch_tok, tree_expression *expr,
                           tree_switch_case_list *list, token *end_tok,
                           octave_comment_list *lc);

    // Build a switch case.
    tree_switch_case *
    make_switch_case (token *case_tok, tree_expression *expr,
                      tree_statement_list *list, octave_comment_list *lc);

    // Build an assignment to a variable.
    tree_expression *
    make_assign_op (int op, tree_argument_list *lhs, token *eq_tok,
                    tree_expression *rhs);

    // Define a script.
    void make_script (tree_statement_list *cmds, tree_statement *end_script);

    // Begin defining a function.
    octave_user_function *
    start_function (tree_parameter_list *param_list, tree_statement_list *body,
                    tree_statement *end_function);

    // Create a no-op statement for end_function.
    tree_statement *make_end (const std::string& type, bool eof, int l, int c);

    // Do most of the work for defining a function.
    octave_user_function *
    frob_function (const std::string& fname, octave_user_function *fcn);

    // Finish defining a function.
    tree_function_def *
    finish_function (tree_parameter_list *ret_list,
                     octave_user_function *fcn, octave_comment_list *lc,
                     int l, int c);

    // Reset state after parsing function.
    void
    recover_from_parsing_function (void);

    tree_funcall *
    make_superclass_ref (const std::string& method_nm,
                         const std::string& class_nm);

    tree_funcall *
    make_meta_class_query (const std::string& class_nm);

    tree_classdef *
    make_classdef (token *tok_val, tree_classdef_attribute_list *a,
                   tree_identifier *id, tree_classdef_superclass_list *sc,
                   tree_classdef_body *body, token *end_tok,
                   octave_comment_list *lc);

    tree_classdef_properties_block *
    make_classdef_properties_block (token *tok_val,
                                    tree_classdef_attribute_list *a,
                                    tree_classdef_property_list *plist,
                                    token *end_tok, octave_comment_list *lc);

    tree_classdef_methods_block *
    make_classdef_methods_block (token *tok_val,
                                 tree_classdef_attribute_list *a,
                                 tree_classdef_methods_list *mlist,
                                 token *end_tok, octave_comment_list *lc);

    tree_classdef_events_block *
    make_classdef_events_block (token *tok_val,
                                tree_classdef_attribute_list *a,
                                tree_classdef_events_list *elist,
                                token *end_tok, octave_comment_list *lc);

    tree_classdef_enum_block *
    make_classdef_enum_block (token *tok_val,
                              tree_classdef_attribute_list *a,
                              tree_classdef_enum_list *elist,
                              token *end_tok, octave_comment_list *lc);

    octave_user_function *
    start_classdef_external_method (tree_identifier *id,
                                    tree_parameter_list *pl);

    tree_function_def *
    finish_classdef_external_method (octave_user_function *fcn,
                                     tree_parameter_list *ret_list,
                                     octave_comment_list *cl);

    // Make an index expression.
    tree_index_expression *
    make_index_expression (tree_expression *expr,
                           tree_argument_list *args, char type);

    // Make an indirect reference expression.
    tree_index_expression *
    make_indirect_ref (tree_expression *expr, const std::string&);

    // Make an indirect reference expression with dynamic field name.
    tree_index_expression *
    make_indirect_ref (tree_expression *expr, tree_expression *field);

    // Make a declaration command.
    tree_decl_command *
    make_decl_command (int tok, token *tok_val, tree_decl_init_list *lst);

    // Validate matrix or cell
    bool validate_array_list (tree_expression *e);

    // Validate matrix object used in "[lhs] = ..." assignments.
    tree_argument_list *validate_matrix_for_assignment (tree_expression *e);

    // Finish building an array_list (common action for finish_matrix
    // and finish_cell).
    tree_expression *finish_array_list (tree_array_list *a);

    // Finish building a matrix list.
    tree_expression *finish_matrix (tree_matrix *m);

    // Finish building a cell list.
    tree_expression *finish_cell (tree_cell *c);

    // Maybe print a warning.  Duh.
    void maybe_warn_missing_semi (tree_statement_list *);

    // Set the print flag for a statement based on the separator type.
    tree_statement_list *
    set_stmt_print_flag (tree_statement_list *, char, bool);

    // Finish building a statement.
    template <typename T>
    tree_statement *make_statement (T *arg);

    // Create a statement list.
    tree_statement_list *make_statement_list (tree_statement *stmt);

    // Append a statement to an existing statement list.
    tree_statement_list *
    append_statement_list (tree_statement_list *list, char sep,
                           tree_statement *stmt, bool warn_missing_semi);

    // Generic error messages.
    void bison_error (const std::string& s, int l = -1, int c = -1);

    // Contains error message if Bison-generated parser returns non-zero
    // status.
    std::string parse_error_msg;

    // Have we found an explicit end to a function?
    bool endfunction_found;

    // TRUE means we are in the process of autoloading a function.
    bool autoloading;

    // TRUE means the current function file was found in a relative path
    // element.
    bool fcn_file_from_relative_lookup;

    // FALSE if we are still at the primary function.  Subfunctions can
    // only be declared inside function files.
    bool parsing_subfunctions;

    // Maximum function depth detected.  Used to determine whether
    // we have nested functions or just implicitly ended subfunctions.
    int max_fcn_depth;

    // = 0 currently outside any function.
    // = 1 inside the primary function or a subfunction.
    // > 1 means we are looking at a function definition that seems to be
    //     inside a function.  Note that the function still might not be a
    //     nested function.
    int curr_fcn_depth;

    // Scope where we install all subfunctions and nested functions.  Only
    // used while reading function files.
    symbol_table::scope_id primary_fcn_scope;

    // Name of the current class when we are parsing class methods or
    // constructors.
    std::string curr_class_name;

    // Name of the current package when we are parsing an element contained
    // in a package directory (+-directory).
    std::string curr_package_name;

    // A stack holding the nested function scopes being parsed.
    // We don't use std::stack, because we want the clear method.  Also, we
    // must access one from the top
    std::vector<symbol_table::scope_id> function_scopes;

    // Pointer to the primary user function or user script function.
    octave_function *primary_fcn_ptr;

    // List of subfunction names, initially in the order they are
    // installed in the symbol table, then ordered as they appear in the
    // file.  Eventually stashed in the primary function object.
    std::list<std::string> subfunction_names;

    // Pointer to the classdef object we just parsed, if any.
    tree_classdef *classdef_object;

    // Result of parsing input.
    tree_statement_list *stmt_list;

    // State of the lexer.
    base_lexer& lexer;

    // Internal state of the Bison parser.
    void *parser_state;

  private:

    // No copying!

    base_parser (const base_parser&);

    base_parser& operator = (const base_parser&);
  };

  class
  parser : public base_parser
  {
  public:

    parser (void)
      : base_parser (*(new octave::lexer ()))
    { }

    parser (FILE *file)
      : base_parser (*(new octave::lexer (file)))
    { }

    parser (const std::string& eval_string)
      : base_parser (*(new octave::lexer (eval_string)))
    { }

    parser (octave::lexer& lxr)
      : base_parser (lxr)
    { }

    ~parser (void) { }

    int run (void);

  private:

    // No copying!

    parser (const parser&);

    parser& operator = (const parser&);
  };

  class
  push_parser : public base_parser
  {
  public:

    push_parser (void)
      : base_parser (*(new octave::push_lexer ()))
    { }

    ~push_parser (void) { }

    int run (const std::string& input, bool eof);

  private:

    // No copying!

    push_parser (const push_parser&);

    push_parser& operator = (const push_parser&);
  };
}

#endif